Electrical power industry restructuring has created highly vibrant and competitive market that altered many aspects of the power industry. In this changed scenario, scarcity of energy resources, increasing power generation cost, environment concern, ever growing demand for electrical energy necessitate optimal economic dispatch. Practical economic dispatch (ED) problems have nonlinear, non-convex type objective function with intense equality and inequality constraints. The conventional optimization methods are not able to solve such problems as due to local optimum solution convergence. Metaheuristic optimization techniques especially Improved Particle Swarm Optimization (IPSO) has gained an incredible recognition as the solution algorithm for such type of ED problems in last decade. The application of IPSO in ED problem, which is considered as one of the most complex optimization problem has been summarized in present paper. This paper illustrates successful implementation of the Improved Particle Swarm Optimization (IPSO) to Economic Load Dispatch Problem (ELD). Power output of each generating unit and optimum fuel cost obtained using IPSO algorithm has been compared with conventional techniques. The results obtained shows that IPSO algorithm converges to optimal fuel cost with reduced computational time when compared to PSO and GA for the three, six and IEEE 30 bus system.
A Hybrid Control Scheme for Fault Ride-Through Capability using Line-Side Con...Suganthi Thangaraj
As the wind power installations are increasing in number, Wind Turbine Generators (WTG) are required to have Fault Ride-Through (FRT) capabilities. Lately developed grid operating codes demand the WTGs to stay connected during fault conditions, supporting the grid to recover faster back to its normal state. In this paper, the generator side converter incorporates the maximum power point tracking algorithm to extract maximum energy from wind turbine system. A hybrid control scheme for energy storage systems (ESS) and braking choppers for fault ride-through capability and a suppression of the output power fluctuation is proposed for permanent-magnet synchronous generator (PMSG) wind turbine systems. During grid faults, the dc-link voltage is controlled by the ESS instead of the line-side converter (LSC), whereas the LSC is exploited as a STATCOM to inject reactive current into the grid for assisting in the grid voltage recovery. A simple model of the proposed system is developed and simulated in MATLAB environment. The effectiveness of the system is validated through extensive simulation results
Modified T-type topology of three-phase multi-level inverter for photovoltaic...IJECEIAES
In this article, a three-phase multilevel neutral-point-clamped inverter with a modified t-type structure of switches is proposed. A pulse width modulation (PWM) scheme of the proposed inverter is also developed. The proposed topology of the multilevel inverter has the advantage of being simple, on the one hand since it does contain only semiconductors in reduced number (corresponding to the number of required voltage levels), and no other components such as switching or flying capacitors, and on the other hand, the control scheme is much simpler and more suitable for variable frequency and voltage control. The performances of this inverter are analyzed through simulations carried out in the MATLAB/Simulink environment on a threephase inverter with 9 levels. In all simulations, the proposed topology is connected with R-load or RL-load without any output filter.
Resource aware wind farm and D-STATCOM optimal sizing and placement in a dist...IJECEIAES
Doubly fed induction generators (DFIG) based wind farms are capable of providing reactive power compensation. Compensation capability enhancement using reactors such as distributed static synchronous compensator (D-STATCOM) while connecting distribution generation (DG) systems to grid is imperative. This paper presents an optimal placement and sizing of offshore wind farms in a coastal distribution system that is emulated on an IEEE 33 bus system. A multi-objective formulation for optimal placement and sizing of the offshore wind farms with both the location and size constraints is developed. Teaching learning algorithm is used to optimize the multi-objective function constraining on the capacity and location of the offshore wind farms. The proposed formulation is a multi-objective problem for placement of the wind generator in the power system with dynamic wind supply to the power system. The random wind speed is generated as the input and the wind farm output generated to perform the optimal sizing and placement in the distributed system. MATLAB based simulation developed is found to be efficient and robust.
Impact of hybrid FACTS devices on the stability of the Kenyan power system IJECEIAES
Flexible alternating current transmission system (FACTS) devices are deployed for improving power system’s stability either singly or as a combination. This research investigates hybrid FACTS devices and studies their impact on voltage, small-signal and transient stability simultaneously under various system disturbances. The simulations were done using five FACTS devices-static var compensator (SVC), static synchronous compensator (STATCOM), static synchronous series compensators (SSSC), thyristor controlled series compensator (TCSC) and unified power flow controller (UPFC) in MATLAB’s power system analysis toolbox (PSAT). These five devices were grouped into ten pairs and tested on Kenya’s transmission network under specific contingencies: the loss of a major generating machine and/or transmission line. The UPFC-STATCOM pair performed the best in all the three aspects under study. The settling times were 3 seconds and 3.05 seconds respectively for voltage and rotor angle improvement on the loss of a major generator at normal operation. The same pair gave settling times of 2.11 seconds and 3.12 seconds for voltage and rotor angle stability improvement respectively on the loss of a major transmission line at 140% system loading. From the study, two novel techniques were developed: A performance-based ranking system and classification for FACTS devices.
This paper presents an online efficiency optimization method for the interior permanent magnet synchronous motor (IPMSM) drive system in an electric vehicle (EV). The proposed method considers accurately the total system losses including fundamental copper and iron losses, harmonic copper and iron losses, magnet loss, and inverter losses. Therefore, it has the capability to always guarantee maximum efficiency control. A highly trusted machine model is built using finite element analysis (FEA). This model considers accurately the magnetic saturation, spatial harmonics, and iron loss effect. The overall system efficiency is estimated online based on the accurate determination of system loss, and then the optimum current angle is defined online for the maximum efficiency per ampere (MEPA) control. A series of results is conducted to show the effectiveness and fidelity of proposed method. The results show the superior performance of proposed method over the conventional offline efficiency optimization methods.
The gravitational search algorithm for incorporating TCSC devices into the sy...IJECEIAES
This paper proposes a gravitational search algorithm (GSA) to allocate the thyristor-controlled series compensator (TCSC) incorporation with the issue of reactive power management. The aim of using TCSC units in this study is to minimize active and reactive power losses. Reserve beyond the thermal border, enhance the voltage profile and increase transmission-lines flow while continuing the whole generation cost of the system a little increase compared with its single goal base case. The optimal power flow (OPF) described is a consideration for finding the best size and location of the TCSCs devices seeing techno-economic subjects for minimizing fuel cost of generation units and the costs of installing TCSCs devices. The GSA algorithm's high ability in solving the proposed multi-objective problem is tested on two 9 and 30 bus test systems. For each test system, four case studies are considered to represent both normal and emergency operating conditions. The proposed GSA method's simulation results show that GSA offers a practical and robust highquality solution for the problem and improves system performance.
Design and fabrication of rotor lateral shifting in the axial-flux permanent-...IJECEIAES
The development of axial-flux permanent-magnet (AFPM) machines has become a mature technology. The single-stator double-rotor (SSDR) AFPM structure has advantages on the compactness and the low up to medium power applications so the microscale size and low-cost applications are reachable to be designed. The research main objectives are designing and manufacturing the lateral shifting from the north poles of the first rotor face the north poles of the second rotor (NN) to the north poles of the first rotor face the south poles of the second rotor (NS) categories as well as finding the best performance of the proposed method and implementing in a low cost and micro-scale AFPMG. The novel lateral shifting on the one of the rotors shows performance at 19.2 0 has the highest efficiency at 88.39% during lateral shifting from N–N (0 0 ) to N–S (36 0 ) on rotor 2.
Design methodology of smart photovoltaic plant IJECEIAES
In this article, we present a new methodology to design an intelligent photovoltaic power plant connected to an electrical grid with storage to supply the laying hen rearing centers. This study requires a very competent design methodology in order to optimize the production and consumption of electrical energy. Our contribution consists in proposing a robust dimensioning synthesis elaborated according to a data flow chart. To achieve this objective, the photovoltaic system was first designed using a deterministic method, then the software "Homer" was used to check the feasibility of the design. Then, controllers (fuzzy logic) were used to optimize the energy produced and consumed. The power produced by the photovoltaic generator (GPV) is optimized by two fuzzy controllers: one to extract the maximum energy and another to control the batteries. The energy consumed by the load is optimized by a fuzzy controller that regulates the internal climate of the livestock buildings. The proposed control strategies are developed and implemented using MATLAB/Simulink.
A Hybrid Control Scheme for Fault Ride-Through Capability using Line-Side Con...Suganthi Thangaraj
As the wind power installations are increasing in number, Wind Turbine Generators (WTG) are required to have Fault Ride-Through (FRT) capabilities. Lately developed grid operating codes demand the WTGs to stay connected during fault conditions, supporting the grid to recover faster back to its normal state. In this paper, the generator side converter incorporates the maximum power point tracking algorithm to extract maximum energy from wind turbine system. A hybrid control scheme for energy storage systems (ESS) and braking choppers for fault ride-through capability and a suppression of the output power fluctuation is proposed for permanent-magnet synchronous generator (PMSG) wind turbine systems. During grid faults, the dc-link voltage is controlled by the ESS instead of the line-side converter (LSC), whereas the LSC is exploited as a STATCOM to inject reactive current into the grid for assisting in the grid voltage recovery. A simple model of the proposed system is developed and simulated in MATLAB environment. The effectiveness of the system is validated through extensive simulation results
Modified T-type topology of three-phase multi-level inverter for photovoltaic...IJECEIAES
In this article, a three-phase multilevel neutral-point-clamped inverter with a modified t-type structure of switches is proposed. A pulse width modulation (PWM) scheme of the proposed inverter is also developed. The proposed topology of the multilevel inverter has the advantage of being simple, on the one hand since it does contain only semiconductors in reduced number (corresponding to the number of required voltage levels), and no other components such as switching or flying capacitors, and on the other hand, the control scheme is much simpler and more suitable for variable frequency and voltage control. The performances of this inverter are analyzed through simulations carried out in the MATLAB/Simulink environment on a threephase inverter with 9 levels. In all simulations, the proposed topology is connected with R-load or RL-load without any output filter.
Resource aware wind farm and D-STATCOM optimal sizing and placement in a dist...IJECEIAES
Doubly fed induction generators (DFIG) based wind farms are capable of providing reactive power compensation. Compensation capability enhancement using reactors such as distributed static synchronous compensator (D-STATCOM) while connecting distribution generation (DG) systems to grid is imperative. This paper presents an optimal placement and sizing of offshore wind farms in a coastal distribution system that is emulated on an IEEE 33 bus system. A multi-objective formulation for optimal placement and sizing of the offshore wind farms with both the location and size constraints is developed. Teaching learning algorithm is used to optimize the multi-objective function constraining on the capacity and location of the offshore wind farms. The proposed formulation is a multi-objective problem for placement of the wind generator in the power system with dynamic wind supply to the power system. The random wind speed is generated as the input and the wind farm output generated to perform the optimal sizing and placement in the distributed system. MATLAB based simulation developed is found to be efficient and robust.
Impact of hybrid FACTS devices on the stability of the Kenyan power system IJECEIAES
Flexible alternating current transmission system (FACTS) devices are deployed for improving power system’s stability either singly or as a combination. This research investigates hybrid FACTS devices and studies their impact on voltage, small-signal and transient stability simultaneously under various system disturbances. The simulations were done using five FACTS devices-static var compensator (SVC), static synchronous compensator (STATCOM), static synchronous series compensators (SSSC), thyristor controlled series compensator (TCSC) and unified power flow controller (UPFC) in MATLAB’s power system analysis toolbox (PSAT). These five devices were grouped into ten pairs and tested on Kenya’s transmission network under specific contingencies: the loss of a major generating machine and/or transmission line. The UPFC-STATCOM pair performed the best in all the three aspects under study. The settling times were 3 seconds and 3.05 seconds respectively for voltage and rotor angle improvement on the loss of a major generator at normal operation. The same pair gave settling times of 2.11 seconds and 3.12 seconds for voltage and rotor angle stability improvement respectively on the loss of a major transmission line at 140% system loading. From the study, two novel techniques were developed: A performance-based ranking system and classification for FACTS devices.
This paper presents an online efficiency optimization method for the interior permanent magnet synchronous motor (IPMSM) drive system in an electric vehicle (EV). The proposed method considers accurately the total system losses including fundamental copper and iron losses, harmonic copper and iron losses, magnet loss, and inverter losses. Therefore, it has the capability to always guarantee maximum efficiency control. A highly trusted machine model is built using finite element analysis (FEA). This model considers accurately the magnetic saturation, spatial harmonics, and iron loss effect. The overall system efficiency is estimated online based on the accurate determination of system loss, and then the optimum current angle is defined online for the maximum efficiency per ampere (MEPA) control. A series of results is conducted to show the effectiveness and fidelity of proposed method. The results show the superior performance of proposed method over the conventional offline efficiency optimization methods.
The gravitational search algorithm for incorporating TCSC devices into the sy...IJECEIAES
This paper proposes a gravitational search algorithm (GSA) to allocate the thyristor-controlled series compensator (TCSC) incorporation with the issue of reactive power management. The aim of using TCSC units in this study is to minimize active and reactive power losses. Reserve beyond the thermal border, enhance the voltage profile and increase transmission-lines flow while continuing the whole generation cost of the system a little increase compared with its single goal base case. The optimal power flow (OPF) described is a consideration for finding the best size and location of the TCSCs devices seeing techno-economic subjects for minimizing fuel cost of generation units and the costs of installing TCSCs devices. The GSA algorithm's high ability in solving the proposed multi-objective problem is tested on two 9 and 30 bus test systems. For each test system, four case studies are considered to represent both normal and emergency operating conditions. The proposed GSA method's simulation results show that GSA offers a practical and robust highquality solution for the problem and improves system performance.
Design and fabrication of rotor lateral shifting in the axial-flux permanent-...IJECEIAES
The development of axial-flux permanent-magnet (AFPM) machines has become a mature technology. The single-stator double-rotor (SSDR) AFPM structure has advantages on the compactness and the low up to medium power applications so the microscale size and low-cost applications are reachable to be designed. The research main objectives are designing and manufacturing the lateral shifting from the north poles of the first rotor face the north poles of the second rotor (NN) to the north poles of the first rotor face the south poles of the second rotor (NS) categories as well as finding the best performance of the proposed method and implementing in a low cost and micro-scale AFPMG. The novel lateral shifting on the one of the rotors shows performance at 19.2 0 has the highest efficiency at 88.39% during lateral shifting from N–N (0 0 ) to N–S (36 0 ) on rotor 2.
Design methodology of smart photovoltaic plant IJECEIAES
In this article, we present a new methodology to design an intelligent photovoltaic power plant connected to an electrical grid with storage to supply the laying hen rearing centers. This study requires a very competent design methodology in order to optimize the production and consumption of electrical energy. Our contribution consists in proposing a robust dimensioning synthesis elaborated according to a data flow chart. To achieve this objective, the photovoltaic system was first designed using a deterministic method, then the software "Homer" was used to check the feasibility of the design. Then, controllers (fuzzy logic) were used to optimize the energy produced and consumed. The power produced by the photovoltaic generator (GPV) is optimized by two fuzzy controllers: one to extract the maximum energy and another to control the batteries. The energy consumed by the load is optimized by a fuzzy controller that regulates the internal climate of the livestock buildings. The proposed control strategies are developed and implemented using MATLAB/Simulink.
Normally, the character of the wind energy as a renewable energy sources has uncertainty in generation. To resolve the Optimal Power Flow (OPF) drawback, this paper proposed a replacement Hybrid Multi Objective Artificial Physical Optimization (HMOAPO) algorithmic rule, which does not require any management parameters compared to different meta-heuristic algorithms within the literature. Artificial Physical Optimization (APO), a moderately new population-based intelligence algorithm, shows fine performance on improvement issues. Moreover, this paper presents hybrid variety of Animal Migration Optimization (AMO) algorithmic rule to express the convergence characteristic of APO. The OPF drawback is taken into account with six totally different check cases, the effectiveness of the proposed HMOAPO technique is tested on IEEE 30-bus, IEEE 118-bus and IEEE 300-bus check system. The obtained results from the HMOAPO algorithm is compared with the other improvement techniques within the literature. The obtained comparison results indicate that proposed technique is effective to succeed in best resolution for the OPF drawback.
Heuristic remedial actions in the reliability assessment of high voltage dire...IJECEIAES
Planning of high voltage direct current (HVDC) grids requires inclusion of reliability assessment of alternatives under study. This paper proposes a methodology to evaluate the adequacy of voltage source converter/VSCHVDC networks. The methodology analyses the performance of the system using N-1 and N-2 contingencies in order to detect weaknesses in the DC network and evaluates two types of remedial actions to keep the entire system under the acceptable operating limits . The remedial actions are applied when a violation of these limits on the DC system occurs; those include topology changes in the network and adjustments of power settings of VSC converter stations. The CIGRE B4 DC grid test system is used for evaluating the reliability/adequacy performance by means of the proposed methodology in this paper. The proposed remedial actions are effective for all contingencies; then, numerical results are as expected. This work is useful for planning and operation of grids based on VSC-HVDC technology.
The development of modeling wind speed plays a very important in helping to obtain the actual wind speed data for the benefit of the power plant planning in the future. The wind speed in this paper is obtained from a PCE-FWS 20 type measuring instrument with a duration of 30 minutes which is accumulated into monthly data for one year (2019). Despite the many wind speed modeling that has been done by researchers. Modeling wind speeds proposed in this study were obtained from the modified Rayleigh distribution. In this study, the Rayleigh scale factor (Cr) and modified Rayleigh scale factor (Cm) were calculated. The observed wind speed is compared with the predicted wind characteristics. The data fit test used correlation coefficient (R2), root means square error (RMSE), and mean absolute percentage error (MAPE). The results of the proposed modified Rayleigh model provide very good results for users.
Coordinated planning in improving power quality considering the use of nonlin...IJECEIAES
Power quality has an important role in the distribution of electrical energy. The use of non-linear load can generate harmonic spread which can reduce the power quality in the radial distribution system. This research is in form of coordinated planning by combining distributed generation placement, capacitor placement and network reconfiguration to simultaneously minimize active power losses, total harmonic distortion (THD), and voltage deviation as an objective function using the particle swarm optimization method. This optimization technique will be tested on two types of networks in the form 33-bus and 69-bus IEEE Standard Test System to show effectiveness of the proposed method. The use of MATLAB programming shows the result of simulation of increasing power quality achieved for all scenario of proposed method.
Small Signal Stability Improvement and Congestion Management Using PSO Based ...IDES Editor
In this paper an attempt has been made to study the
application of Thyristor Controlled Series Capacitor (TCSC)
to mitigate small signal stability problem in addition to
congestion management of a heavily loaded line in a
multimachine power system. The Flexible AC Transmission
System (FACTS) devices such as TCSC can be used to control
the power flows in the network and can help in improvement
of small signal stability aspect. It can also provide relief to
congestion in the heavily loaded line. However, the
performance of any FACTS device highly depends upon its
parameters and placement at suitable locations in the power
network. In this paper, Particle Swarm Optimization (PSO)
method has been used for determining the optimal locations
and parameters of the TCSC controller in order to damp small
signal oscillations. Transmission Line Flow (TLF) Sensitivity
method has been used for curtailment of non-firm load to
limit power flow congestion. The results of simulation reveals
that TCSC controllers, placed optimally, not only mitigate
small signal oscillations but they can also alleviate line flow
congestion effectively.
Optimizing of the installed capacity of hybrid renewable energy with a modifi...IJECEIAES
The lack of wind speed capacity and the emission of photons from sunlight are the problem in a hybrid system of photovoltaic (PV) panels and wind turbines. To overcome this shortcoming, the incremental conductance (IC) algorithm is applied that could control the converter work cycle and the switching of the buck boost therefore maximum efficiency of maximum power point tracking (MPPT) is reached. The operation of the PV-wind hybrid system, consisting of a 100 W PV array device and a 400 W wind subsystem, 12 V/100 Ah battery energy storage and LED, the PV-wind system requires a hybrid controller for battery charging and usage and load lamp and it’s conducted in experimental setup. The experimental has shown that an average increase in power generated was 38.8% compared to a single system of PV panels or a single wind turbine sub-system. Therefore, the potential opportunities for increasing power production in the tropics wheather could be carried out and applied with this model.
Frequency regulation service of multiple-areas vehicle to grid application in...IJECEIAES
Regarding a potential of electric vehicles, it has been widely discussed that the electric vehicle can be participated in electricity ancillary services. Among the ancillary service products, the system frequency regulation is often considered. However, the participation in this service has to be conformed to the hierarchical frequency control architecture. Therefore, the vehicle to grid (V2G) application in this article is proposed in the term of multiple-areas of operation. The multiple-areas in this article are concerned as parking areas, which the parking areas can be implied as a V2G operator. From that, V2G operator can obtain the control signal from hierarchical control architecture for power sharing purpose. A power sharing concept between areas is fulfilled by a proposed adaptive droop factor based on battery state of charge and available capacity of parking area. A nonlinear multiplier factor is used for the droop adaptation. An available capacity is also applied as a limitation for the V2G operation. The available capacity is analyzed through a stochastic character. As the V2G application has to be cooperated with the hierarchical control functions, i.e. primary control and secondary control, then the effect of V2G on hierarchical control functions is investigated and discussed.
The optimal solution for unit commitment problem using binary hybrid grey wol...IJECEIAES
The aim of this work is to solve the unit commitment (UC) problem in power systems by calculating minimum production cost for the power generation and finding the best distribution of the generation among the units (units scheduling) using binary grey wolf optimizer based on particle swarm optimization (BGWOPSO) algorithm. The minimum production cost calculating is based on using the quadratic programming method and represents the global solution that must be arriving by the BGWOPSO algorithm then appearing units status (on or off). The suggested method was applied on “39 bus IEEE test systems”, the simulation results show the effectiveness of the suggested method over other algorithms in terms of minimizing of production cost and suggesting excellent scheduling of units.
Power system operation considering detailed modelling of the natural gas supp...IJECEIAES
The energy transition from fossil-fuel generators to renewable energies represents a paramount challenge. This is mainly due to the uncertainty and unpredictability associated with renewable resources. A greater flexibility is requested for power system operation to fulfill demand requirements considering security and economic restrictions. In particular, the use of gas-fired generators has increased to enhance system flexibility in response to the integration of renewable energy sources. This paper provides a comprehensive formulation for modeling a natural gas supply network to provide gas for thermal generators, considering the use of wind power sources for the operation of the electrical system over a 24-hour period. The results indicate the requirements of gas with different wind power level of integration. The model is evaluated on a network of 20 NG nodes and on a 24-bus IEEE RTS system with various operative settings during a 24-hour period.
An optimum location of on-grid bifacial based photovoltaic system in Iraq IJECEIAES
Bifacial photovoltaic (PV) module can gain 30% more energy compared to monofacial if a suitable location were chosen. Iraq (a Middle East country) has a variable irradiation level according to its geographic coordinates, thus, the performance of PV systems differs. This paper an array (17 series, 13 parallel) was chosen to produce 100 kWp for an on-grid PV system. It investigates the PV system in three cities in Iraq (Mosul, Baghdad, and Basrah). Effect of albedo factor, high and pitch of the bifacial module on energy yield have been studied using PVsyst (software). It has been found that the effect is less for a pitch greater than 6 m. The energy gained from bifacial and monofacial PV system module in these cities shows that Mosul is the most suitable for installing both PV systems followed by Baghdad and lastly Basrah. However, in Basrah, the bifacial gain is 12% higher in the energy than monofacial as irradiation there is higher than the other locations, especially for elevation above 1.5 m. Moreover, the cost of bifacial array is 7.23% higher than monofacial, but this additional cost is acceptable since the bifacial gain is about 11.3% higher energy compared to the monofacial.
Benchmarking study between capacitive and electronic load technic to track I-...IJECEIAES
To detect defects of solar panel and understand the effect of external parameters such as fluctuations in illumination, temperature, and the effect of a type of dust on a photovoltaic (PV) panel, it is essential to plot the Ipv=f(Vpv) characteristic of the PV panel, and the simplest way to plot this I-V characteristic is to use a variable resistor. This paper presents a study of comparison and combination between two methods: capacitive and electronic loading to track I-V characteristic. The comparison was performed in terms of accuracy, response time and instrumentation cost used in each circuit, under standard temperature and illumination conditions by using polycrystalline solar panel type SX330J and monocrystalline solar panels type ET-M53630. The whole system is based on simple components, less expensive and especially widely used in laboratories. The results will be between the datasheet of the manufacturer with the experimental data, refinements and improvements concerning the number of points and the trace time have been made by combining these two methods.
Stand-alone applications of Photovoltaic (PV) can be found in water pumping systems for rural area. The proper electric motor must be chosen for optimal considerations. One of the modern electric motor called brushless motor (BLDC) can be an alternative for this application although it has complexity in control. Powering such a motor by using electric energy generating by PV modules will be an interesting problem. In this paper, a PV powered BLDC motor system is proposed. The PV modules must produce maximum power at any instant time and then this power must be able to rotate the motor. By combining sequential stator energizing due to a rotor detection and a PWM concept, the speed of BLDC can be controlled. Meanwhile, to get maximum power of PV modules, detection of voltage and current of the modules are required to be calculated. Digital Signal Control (DSC) is implemented to handle this control strategy and locks the width of the PWM signal to maintain the PV modules under maximum power operation. The effectiveness of the proposed system has been verified by simulation works. Finally the experimental works were done to validate.
In industrial electric drive systems, it is common to find objects that need to solve the problem of angular position control, moving the object from one position to another asymptotically with no over-correction and guarantee. calculation of maximum fast impact. This is a multi-target optimization problem with many different solutions. This paper presents a method of constructing a PMSM motor position controller with a variable structure using dSPACE 1104 card. The system consists of a position control loop with a variable structure that is an outer loop and a speed control loop degree is the inner loop. In which, the speed adjustment loop uses adaptive law to compensate for uncertain functions and build a sliding mode observation to estimate load torque, friction and noise. The results of the simulation study were verified on Matlab-Simulink environment and experimented on dSPACE 1104 card to check the correctness of the built controller algorithm. The research results in the paper are the basis for the evaluation and setting up of control algorithms, design of electric drive systems in industry and the military.
The hardware implementation of sensorless brushless direct current motor drive incorporating H-infinity control strategy with optimized weights by particle swarm optimization in the speed control is carried out in this work. The methodology involved in the design of brushless direct current (BLDC) motor control with sensorless position detection technique, the design of H-infinity speed controller, steps involved in particle swarm optimization for optimizing coefficients of its weights and the hardware implementation is discussed in detail in this paper. Texas Instruments microcontroller board C2000 Delfino Launchpad LAUNCHXL F28377S and driver BOOSTXL DRV8301 are used for realization of the speed controller. The code is developed using C2000 hardware support package in MATLAB/SIMULINK platform. A comprehensive performance analysis is accomplished during starting of the motor and during the fast application and removal of load. This strategy is found to be robust resulting in faster load disturbance rejection and better reference speed tracking. The experimental results of the proposed strategy are compared with that of conventional proportional-integral (PI) controller. The time domain parameters are also compared. It is found that the proposed strategy exhibits better performance characteristics during transients and sudden disturbances in load.
Decentralised PI controller design based on dynamic interaction decoupling in...IJECEIAES
An enhanced method for design of decenralised proportional integral (PI) controllers to control various variables of flotation columns is proposed. These columns are multivariable processes characterised by multiple interacting manipulated and controlled variables. The control of more than one variable is not an easy problem to solve as a change in a specific manipulated variable affects more than one controlled variable. Paper proposes an improved method for design of decentralized PI controllers through the introduction of decoupling of the interconnected model of the process. Decoupling the system model has proven to be an effective strategy to reduce the influence of the interactions in the closed-loop control and consistently to keep the system stable. The mathematical derivations and the algorithm of the design procedure are described in detail. The behaviour and performance of the closed-loop systems without and with the application of the decoupling method was investigated and compared through simulations in MATLAB/Simulink. The results show that the decouplers - based closedloop system has better performance than the closed-loop system without decouplers. The highest improvement (2 to 50 times) is in the steady-state error and 1.2 to 7 times in the settling and rising time. Controllers can easily be implemented.
This paper presents simulation and experimental results of anti-windup PI controller to improve induction machine speed control based on direct torque control (DTC) strategy. Problems like rollover can arise in conventional PI controller due to saturation effect. In order to avoid such problems anti-windup PI controller is presented. This controller is simple for implementation in practice. The proposed anti-windup PI controller demonstrates better dynamic step changes response in speed in terms of overshoots. All simulation work was done using Simulink in the MATLAB software. The experimental results were obtained by practical implementation on a dSPACE 1104 board for a 1.5 KW induction machine. Simulation and experimental results have proven a good performance and verified the validity of the presented control strategy.
Optimal Placement of D-STATCOM Using Hybrid Genetic and Ant Colony Algorithm ...IJAPEJOURNAL
In this work, a modern algorithm by hybrid genetic algorithm and ant colony algorithm is designed to placement and then simulated to determine the amount of reactive power by D-STATCOM. Also this method will be able to minimize the power system losses that contain power loss in transmission lines. Furthermore, in this design a IEEE 30-bus model depicted and three D-STATCOM are located in this system according to Economic Considerations. The optimal placement of each D-STATCOM is computed by the ant colony algorithm. In order to optimize placement for each D-STATCOM, two groups of ant are selected, which respectively located in near nest and far from the nest. Moreover, for every output simulation of D-STATCOM that is used to produce or absorb of reactive power, a genetic algorithm to minimizing the total network losses is applied. Finally, the result of this simulation shows net losses reduction about 150% that it verifies the new algorithm performance.
Single core configurations of saturated core fault current limiter performanc...IJECEIAES
Economic growth with industrialization and urbanization lead to an extensive increase in power demand. It forced the utilities to add power generating facilities to cause the necessary demand-generation balance. The bulk power generating stations, mostly interconnected, with the penetration of distributed generation result in an enormous rise in the fault level of power networks. It necessitates for electrical utilities to control the fault current so that the existing switchgear can continue its services without upgradation or replacement for reliable supply. The deployment of fault current limiter (FCL) at the distribution and transmission networks has been under investigation as a potential solution to the problem. A saturated core fault current limiter (SCFCL) technology is a smart, scalable, efficient, reliable, and commercially viable option to manage fault levels in existing and future MV/HV supply systems. This paper presents the comparative performance analysis of two single-core SCFCL topologies impressed with different core saturations. It has demonstrated that the single AC winding configuration needs more bias power for affecting the same current limiting performance with an acceptable steady-state voltage drop contribution. The fault state impedance has a transient nature, and the optimum bias selection is a critical design parameter in realizing the SCFCL applications.
Normally, the character of the wind energy as a renewable energy sources has uncertainty in generation. To resolve the Optimal Power Flow (OPF) drawback, this paper proposed a replacement Hybrid Multi Objective Artificial Physical Optimization (HMOAPO) algorithmic rule, which does not require any management parameters compared to different meta-heuristic algorithms within the literature. Artificial Physical Optimization (APO), a moderately new population-based intelligence algorithm, shows fine performance on improvement issues. Moreover, this paper presents hybrid variety of Animal Migration Optimization (AMO) algorithmic rule to express the convergence characteristic of APO. The OPF drawback is taken into account with six totally different check cases, the effectiveness of the proposed HMOAPO technique is tested on IEEE 30-bus, IEEE 118-bus and IEEE 300-bus check system. The obtained results from the HMOAPO algorithm is compared with the other improvement techniques within the literature. The obtained comparison results indicate that proposed technique is effective to succeed in best resolution for the OPF drawback.
Heuristic remedial actions in the reliability assessment of high voltage dire...IJECEIAES
Planning of high voltage direct current (HVDC) grids requires inclusion of reliability assessment of alternatives under study. This paper proposes a methodology to evaluate the adequacy of voltage source converter/VSCHVDC networks. The methodology analyses the performance of the system using N-1 and N-2 contingencies in order to detect weaknesses in the DC network and evaluates two types of remedial actions to keep the entire system under the acceptable operating limits . The remedial actions are applied when a violation of these limits on the DC system occurs; those include topology changes in the network and adjustments of power settings of VSC converter stations. The CIGRE B4 DC grid test system is used for evaluating the reliability/adequacy performance by means of the proposed methodology in this paper. The proposed remedial actions are effective for all contingencies; then, numerical results are as expected. This work is useful for planning and operation of grids based on VSC-HVDC technology.
The development of modeling wind speed plays a very important in helping to obtain the actual wind speed data for the benefit of the power plant planning in the future. The wind speed in this paper is obtained from a PCE-FWS 20 type measuring instrument with a duration of 30 minutes which is accumulated into monthly data for one year (2019). Despite the many wind speed modeling that has been done by researchers. Modeling wind speeds proposed in this study were obtained from the modified Rayleigh distribution. In this study, the Rayleigh scale factor (Cr) and modified Rayleigh scale factor (Cm) were calculated. The observed wind speed is compared with the predicted wind characteristics. The data fit test used correlation coefficient (R2), root means square error (RMSE), and mean absolute percentage error (MAPE). The results of the proposed modified Rayleigh model provide very good results for users.
Coordinated planning in improving power quality considering the use of nonlin...IJECEIAES
Power quality has an important role in the distribution of electrical energy. The use of non-linear load can generate harmonic spread which can reduce the power quality in the radial distribution system. This research is in form of coordinated planning by combining distributed generation placement, capacitor placement and network reconfiguration to simultaneously minimize active power losses, total harmonic distortion (THD), and voltage deviation as an objective function using the particle swarm optimization method. This optimization technique will be tested on two types of networks in the form 33-bus and 69-bus IEEE Standard Test System to show effectiveness of the proposed method. The use of MATLAB programming shows the result of simulation of increasing power quality achieved for all scenario of proposed method.
Small Signal Stability Improvement and Congestion Management Using PSO Based ...IDES Editor
In this paper an attempt has been made to study the
application of Thyristor Controlled Series Capacitor (TCSC)
to mitigate small signal stability problem in addition to
congestion management of a heavily loaded line in a
multimachine power system. The Flexible AC Transmission
System (FACTS) devices such as TCSC can be used to control
the power flows in the network and can help in improvement
of small signal stability aspect. It can also provide relief to
congestion in the heavily loaded line. However, the
performance of any FACTS device highly depends upon its
parameters and placement at suitable locations in the power
network. In this paper, Particle Swarm Optimization (PSO)
method has been used for determining the optimal locations
and parameters of the TCSC controller in order to damp small
signal oscillations. Transmission Line Flow (TLF) Sensitivity
method has been used for curtailment of non-firm load to
limit power flow congestion. The results of simulation reveals
that TCSC controllers, placed optimally, not only mitigate
small signal oscillations but they can also alleviate line flow
congestion effectively.
Optimizing of the installed capacity of hybrid renewable energy with a modifi...IJECEIAES
The lack of wind speed capacity and the emission of photons from sunlight are the problem in a hybrid system of photovoltaic (PV) panels and wind turbines. To overcome this shortcoming, the incremental conductance (IC) algorithm is applied that could control the converter work cycle and the switching of the buck boost therefore maximum efficiency of maximum power point tracking (MPPT) is reached. The operation of the PV-wind hybrid system, consisting of a 100 W PV array device and a 400 W wind subsystem, 12 V/100 Ah battery energy storage and LED, the PV-wind system requires a hybrid controller for battery charging and usage and load lamp and it’s conducted in experimental setup. The experimental has shown that an average increase in power generated was 38.8% compared to a single system of PV panels or a single wind turbine sub-system. Therefore, the potential opportunities for increasing power production in the tropics wheather could be carried out and applied with this model.
Frequency regulation service of multiple-areas vehicle to grid application in...IJECEIAES
Regarding a potential of electric vehicles, it has been widely discussed that the electric vehicle can be participated in electricity ancillary services. Among the ancillary service products, the system frequency regulation is often considered. However, the participation in this service has to be conformed to the hierarchical frequency control architecture. Therefore, the vehicle to grid (V2G) application in this article is proposed in the term of multiple-areas of operation. The multiple-areas in this article are concerned as parking areas, which the parking areas can be implied as a V2G operator. From that, V2G operator can obtain the control signal from hierarchical control architecture for power sharing purpose. A power sharing concept between areas is fulfilled by a proposed adaptive droop factor based on battery state of charge and available capacity of parking area. A nonlinear multiplier factor is used for the droop adaptation. An available capacity is also applied as a limitation for the V2G operation. The available capacity is analyzed through a stochastic character. As the V2G application has to be cooperated with the hierarchical control functions, i.e. primary control and secondary control, then the effect of V2G on hierarchical control functions is investigated and discussed.
The optimal solution for unit commitment problem using binary hybrid grey wol...IJECEIAES
The aim of this work is to solve the unit commitment (UC) problem in power systems by calculating minimum production cost for the power generation and finding the best distribution of the generation among the units (units scheduling) using binary grey wolf optimizer based on particle swarm optimization (BGWOPSO) algorithm. The minimum production cost calculating is based on using the quadratic programming method and represents the global solution that must be arriving by the BGWOPSO algorithm then appearing units status (on or off). The suggested method was applied on “39 bus IEEE test systems”, the simulation results show the effectiveness of the suggested method over other algorithms in terms of minimizing of production cost and suggesting excellent scheduling of units.
Power system operation considering detailed modelling of the natural gas supp...IJECEIAES
The energy transition from fossil-fuel generators to renewable energies represents a paramount challenge. This is mainly due to the uncertainty and unpredictability associated with renewable resources. A greater flexibility is requested for power system operation to fulfill demand requirements considering security and economic restrictions. In particular, the use of gas-fired generators has increased to enhance system flexibility in response to the integration of renewable energy sources. This paper provides a comprehensive formulation for modeling a natural gas supply network to provide gas for thermal generators, considering the use of wind power sources for the operation of the electrical system over a 24-hour period. The results indicate the requirements of gas with different wind power level of integration. The model is evaluated on a network of 20 NG nodes and on a 24-bus IEEE RTS system with various operative settings during a 24-hour period.
An optimum location of on-grid bifacial based photovoltaic system in Iraq IJECEIAES
Bifacial photovoltaic (PV) module can gain 30% more energy compared to monofacial if a suitable location were chosen. Iraq (a Middle East country) has a variable irradiation level according to its geographic coordinates, thus, the performance of PV systems differs. This paper an array (17 series, 13 parallel) was chosen to produce 100 kWp for an on-grid PV system. It investigates the PV system in three cities in Iraq (Mosul, Baghdad, and Basrah). Effect of albedo factor, high and pitch of the bifacial module on energy yield have been studied using PVsyst (software). It has been found that the effect is less for a pitch greater than 6 m. The energy gained from bifacial and monofacial PV system module in these cities shows that Mosul is the most suitable for installing both PV systems followed by Baghdad and lastly Basrah. However, in Basrah, the bifacial gain is 12% higher in the energy than monofacial as irradiation there is higher than the other locations, especially for elevation above 1.5 m. Moreover, the cost of bifacial array is 7.23% higher than monofacial, but this additional cost is acceptable since the bifacial gain is about 11.3% higher energy compared to the monofacial.
Benchmarking study between capacitive and electronic load technic to track I-...IJECEIAES
To detect defects of solar panel and understand the effect of external parameters such as fluctuations in illumination, temperature, and the effect of a type of dust on a photovoltaic (PV) panel, it is essential to plot the Ipv=f(Vpv) characteristic of the PV panel, and the simplest way to plot this I-V characteristic is to use a variable resistor. This paper presents a study of comparison and combination between two methods: capacitive and electronic loading to track I-V characteristic. The comparison was performed in terms of accuracy, response time and instrumentation cost used in each circuit, under standard temperature and illumination conditions by using polycrystalline solar panel type SX330J and monocrystalline solar panels type ET-M53630. The whole system is based on simple components, less expensive and especially widely used in laboratories. The results will be between the datasheet of the manufacturer with the experimental data, refinements and improvements concerning the number of points and the trace time have been made by combining these two methods.
Stand-alone applications of Photovoltaic (PV) can be found in water pumping systems for rural area. The proper electric motor must be chosen for optimal considerations. One of the modern electric motor called brushless motor (BLDC) can be an alternative for this application although it has complexity in control. Powering such a motor by using electric energy generating by PV modules will be an interesting problem. In this paper, a PV powered BLDC motor system is proposed. The PV modules must produce maximum power at any instant time and then this power must be able to rotate the motor. By combining sequential stator energizing due to a rotor detection and a PWM concept, the speed of BLDC can be controlled. Meanwhile, to get maximum power of PV modules, detection of voltage and current of the modules are required to be calculated. Digital Signal Control (DSC) is implemented to handle this control strategy and locks the width of the PWM signal to maintain the PV modules under maximum power operation. The effectiveness of the proposed system has been verified by simulation works. Finally the experimental works were done to validate.
In industrial electric drive systems, it is common to find objects that need to solve the problem of angular position control, moving the object from one position to another asymptotically with no over-correction and guarantee. calculation of maximum fast impact. This is a multi-target optimization problem with many different solutions. This paper presents a method of constructing a PMSM motor position controller with a variable structure using dSPACE 1104 card. The system consists of a position control loop with a variable structure that is an outer loop and a speed control loop degree is the inner loop. In which, the speed adjustment loop uses adaptive law to compensate for uncertain functions and build a sliding mode observation to estimate load torque, friction and noise. The results of the simulation study were verified on Matlab-Simulink environment and experimented on dSPACE 1104 card to check the correctness of the built controller algorithm. The research results in the paper are the basis for the evaluation and setting up of control algorithms, design of electric drive systems in industry and the military.
The hardware implementation of sensorless brushless direct current motor drive incorporating H-infinity control strategy with optimized weights by particle swarm optimization in the speed control is carried out in this work. The methodology involved in the design of brushless direct current (BLDC) motor control with sensorless position detection technique, the design of H-infinity speed controller, steps involved in particle swarm optimization for optimizing coefficients of its weights and the hardware implementation is discussed in detail in this paper. Texas Instruments microcontroller board C2000 Delfino Launchpad LAUNCHXL F28377S and driver BOOSTXL DRV8301 are used for realization of the speed controller. The code is developed using C2000 hardware support package in MATLAB/SIMULINK platform. A comprehensive performance analysis is accomplished during starting of the motor and during the fast application and removal of load. This strategy is found to be robust resulting in faster load disturbance rejection and better reference speed tracking. The experimental results of the proposed strategy are compared with that of conventional proportional-integral (PI) controller. The time domain parameters are also compared. It is found that the proposed strategy exhibits better performance characteristics during transients and sudden disturbances in load.
Decentralised PI controller design based on dynamic interaction decoupling in...IJECEIAES
An enhanced method for design of decenralised proportional integral (PI) controllers to control various variables of flotation columns is proposed. These columns are multivariable processes characterised by multiple interacting manipulated and controlled variables. The control of more than one variable is not an easy problem to solve as a change in a specific manipulated variable affects more than one controlled variable. Paper proposes an improved method for design of decentralized PI controllers through the introduction of decoupling of the interconnected model of the process. Decoupling the system model has proven to be an effective strategy to reduce the influence of the interactions in the closed-loop control and consistently to keep the system stable. The mathematical derivations and the algorithm of the design procedure are described in detail. The behaviour and performance of the closed-loop systems without and with the application of the decoupling method was investigated and compared through simulations in MATLAB/Simulink. The results show that the decouplers - based closedloop system has better performance than the closed-loop system without decouplers. The highest improvement (2 to 50 times) is in the steady-state error and 1.2 to 7 times in the settling and rising time. Controllers can easily be implemented.
This paper presents simulation and experimental results of anti-windup PI controller to improve induction machine speed control based on direct torque control (DTC) strategy. Problems like rollover can arise in conventional PI controller due to saturation effect. In order to avoid such problems anti-windup PI controller is presented. This controller is simple for implementation in practice. The proposed anti-windup PI controller demonstrates better dynamic step changes response in speed in terms of overshoots. All simulation work was done using Simulink in the MATLAB software. The experimental results were obtained by practical implementation on a dSPACE 1104 board for a 1.5 KW induction machine. Simulation and experimental results have proven a good performance and verified the validity of the presented control strategy.
Optimal Placement of D-STATCOM Using Hybrid Genetic and Ant Colony Algorithm ...IJAPEJOURNAL
In this work, a modern algorithm by hybrid genetic algorithm and ant colony algorithm is designed to placement and then simulated to determine the amount of reactive power by D-STATCOM. Also this method will be able to minimize the power system losses that contain power loss in transmission lines. Furthermore, in this design a IEEE 30-bus model depicted and three D-STATCOM are located in this system according to Economic Considerations. The optimal placement of each D-STATCOM is computed by the ant colony algorithm. In order to optimize placement for each D-STATCOM, two groups of ant are selected, which respectively located in near nest and far from the nest. Moreover, for every output simulation of D-STATCOM that is used to produce or absorb of reactive power, a genetic algorithm to minimizing the total network losses is applied. Finally, the result of this simulation shows net losses reduction about 150% that it verifies the new algorithm performance.
Single core configurations of saturated core fault current limiter performanc...IJECEIAES
Economic growth with industrialization and urbanization lead to an extensive increase in power demand. It forced the utilities to add power generating facilities to cause the necessary demand-generation balance. The bulk power generating stations, mostly interconnected, with the penetration of distributed generation result in an enormous rise in the fault level of power networks. It necessitates for electrical utilities to control the fault current so that the existing switchgear can continue its services without upgradation or replacement for reliable supply. The deployment of fault current limiter (FCL) at the distribution and transmission networks has been under investigation as a potential solution to the problem. A saturated core fault current limiter (SCFCL) technology is a smart, scalable, efficient, reliable, and commercially viable option to manage fault levels in existing and future MV/HV supply systems. This paper presents the comparative performance analysis of two single-core SCFCL topologies impressed with different core saturations. It has demonstrated that the single AC winding configuration needs more bias power for affecting the same current limiting performance with an acceptable steady-state voltage drop contribution. The fault state impedance has a transient nature, and the optimum bias selection is a critical design parameter in realizing the SCFCL applications.
Multi Area Economic Dispatch Using Secant Method and Tie Line MatrixIJAPEJOURNAL
In this paper, Secant method and tie line matrix are proposed to solve multi area economic dispatch (MAED) problem with tie line loss. Generator limits of all generators in each area are calculated at given area power demands plus export (or import) using secant method and the generator limits of all generators are modified as modified generator limits. Central economic dispatch (CED) problem is used to determine the output powers of all generators and finally power flows in all tie lines are determined from tie line matrix. Here, Secant method is applied to solve the CED problem. A modified tie line matrix is used to find power flow in each tie line and then tie line loss is calculated from the power flow in each tie line. The proposed approach has been tested on two-area (two generators in each area) system and four-area (four generators in each area) system. It is observed from various cases that the proposed approach provides optimally best solution in terms of cost with tie line loss with less computational burden.
Improvement of voltage profile for large scale power system using soft comput...TELKOMNIKA JOURNAL
In modern power system operation, control, and planning, reactive power as part of power system component is very important in order to supply electrical load such as an electric motor. However, the reactive current that flows from the generator to load demand can cause voltage drop and active power loss. Hence, it is essential to install a compensating device such as a shunt capacitor close to the load bus to improve the voltage profile and decrease the total power loss of transmission line system. This paper presents the application of a genetic algorithm (GA), particle swarm optimization (PSO), and artificial bee colony (ABC)) to obtain the optimal size of the shunt capacitor where those capacitors are located on the critical bus. The effectiveness of the proposed technique is examined by utilizing Java-Madura-Bali (JAMALI) 500 kV power system grid as the test system. From the simulation results, the PSO and ABC algorithms are providing satisfactory results in obtaining the capacitor size and can reduce the total power loss of around 15.873 MW. Moreover, a different result is showed by the GA approach where the power loss in the JAMALI 500kV power grid can be compressed only up to 15.54 MW or 11.38% from the power system operation without a shunt capacitor. The three soft computing techniques could also maintain the voltage profile within 1.05 p.u and 0.95 p.u.
Evolutionary algorithm solution for economic dispatch problemsIJECEIAES
A modified firefly algorithm (FA) was presented in this paper for finding a solution to the economic dispatch (ED) problem. ED is considered a difficult topic in the field of power systems due to the complexity of calculating the optimal generation schedule that will satisfy the demand for electric power at the lowest fuel costs while satisfying all the other constraints. Furthermore, the ED problems are associated with objective functions that have both quality and inequality constraints, these include the practical operation constraints of the generators (such as the forbidden working areas, nonlinear limits, and generation limits) that makes the calculation of the global optimal solutions of ED a difficult task. The proposed approach in this study was evaluated in the IEEE 30-Bus test-bed, the evaluation showed that the proposed FA-based approach performed optimally in comparison with the performance of the other existing optimizers, such as the traditional FA and particle swarm optimization. The results show the high performance of the modified firefly algorithm compared to the other methods.
Economic dispatch by optimization techniquesIJECEIAES
The current paper offers the solution strategy for the economic dispatch problem in electric power system implementing ant lion optimization algorithm (ALOA) and bat algorithm (BA) techniques. In the power network, the economic dispatch (ED) is a short-term calculation of the optimum performance of several electricity generations or a plan of outputs of all usable power generation units from the energy produced to fulfill the necessary demand, although equivalent and unequal specifications need to be achieved at minimal fuel and carbon pollution costs. In this paper, two recent meta-heuristic approaches are introduced, the BA and ALOA. A rigorous stochastically developmental computing strategy focused on the action and intellect of ant lions is an ALOA. The ALOA imitates ant lions' hunting process. The introduction of a numerical description of its biological actions for the solution of ED in the power framework. These algorithms are applied to two systems: a small scale three generator system and a large scale six generator. Results show were compared on the metrics of convergence rate, cost, and average run time that the ALOA and BA are suitable for economic dispatch studies which is clear in the comparison set with other algorithms. Both of these algorithms are tested on IEEE-30 bus reliability test system.
This paper discusses the possible applications of particle swarm optimization (PSO) in the Power system. One of the problems in Power System is Economic Load dispatch (ED). The discussion is carried out in view of the saving money, computational speed – up and expandability that can be achieved by using PSO method. The general approach of the method of this paper is that of Dynamic Programming Method coupled with PSO method. The feasibility of the proposed method is demonstrated, and it is compared with the lambda iterative method in terms of the solution quality and computation efficiency. The experimental results show that the proposed PSO method was indeed capable of obtaining higher quality solutions efficiently in ED problems.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Determining the Pareto front of distributed generator and static VAR compens...IJECEIAES
The integration of distributed generators (DGs), which are based on renewable energy sources, energy storage systems, and static VAR compensators (SVCs), requires considering more challenging operational cases due to the variability of DG production contributed by different characteristics for different time sequences. The size, quantity, technology, and location of DG units have major effects on the system to benefit from the integration. All these aspects create a multi-objective scope; therefore, it is considered a multi-objective mixed-integer optimization problem. This paper presents an improved multi-objective salp swarm optimization algorithm (MOSSA) to obtain multiple Pareto efficient solutions for the optimal number, location, and capacity of DGs and the controlling strategy of SVC a radial distribution system. MOSSA is a bio-inspired optimizer based on swarm intelligence techniques and it is used in finding the optimal solution for a global optimization problem. Two sets of objective functions have been formulated minimizing DGs and SVC cost, voltage violation, energy losses, and system emission cost. The usefulness of the proposed MOSSA has been tested with the 33-bus and 141-bus radial distribution systems and the qualitative comparisons against two well-known algorithms, multiple objective evolutionary algorithms based on decomposition (MOEA/D), and multiple objective particle swarm optimization (MOPSO) algorithm.
Optimal power flow with distributed energy sources using whale optimization a...IJECEIAES
Renewable energy generation is increasingly attractive since it is non-polluting and viable. Recently, the technical and economic performance of power system networks has been enhanced by integrating renewable energy sources (RES). This work focuses on the size of solar and wind production by replacing the thermal generation to decrease cost and losses on a big electrical power system. The Weibull and Lognormal probability density functions are used to calculate the deliverable power of wind and solar energy, to be integrated into the power system. Due to the uncertain and intermittent conditions of these sources, their integration complicates the optimal power flow problem. This paper proposes an optimal power flow (OPF) using the whale optimization algorithm (WOA), to solve for the stochastic wind and solar power integrated power system. In this paper, the ideal capacity of RES along with thermal generators has been determined by considering total generation cost as an objective function. The proposed methodology is tested on the IEEE-30 system to ensure its usefulness. Obtained results show the effectiveness of WOA when compared with other algorithms like non-dominated sorting genetic algorithm (NSGA-II), grey wolf optimization (GWO) and particle swarm optimization-GWO (PSOGWO).
Optimal Reactive Power Scheduling Using Cuckoo Search AlgorithmIJECEIAES
The article describes multidisciplinary design process of high-performance electric generator for advanced aircrafts by analytical methods and computer modeling techniques (electromagnetic, thermal and mechanical calculations). New technical solutions used in its development are described. The main ideas are revealed of the method of EG voltage stabilization we used. To improve the heat dissipation efficiency, we have developed a new cooling system, and provide its study and description in this paper. The advantages of this cooling system include the fact that EG is made with dry, uncooled rotor. This allowed eliminating additional pumps, and significantly reducing tThis paper solves an optimal reactive power scheduling problem in the deregulated power system using the evolutionary based Cuckoo Search Algorithm (CSA). Reactive power scheduling is a very important problem in the power system operation, which is a nonlinear and mixed integer programming problem. It optimizes a specific objective function while satisfying all the equality and inequality constraints. In this paper, CSA is used to determine the optimal settings of control variables such as generator voltages, transformer tap positions and the amount of reactive compensation required to optimize the certain objective functions. The CSA algorithm has been developed from the inspiration that the obligate brood parasitism of some Cuckoo species lay their eggs in nests of other host birds which are of other species. The performance of CSA for solving the proposed optimal reactive power scheduling problem is examined on standard Ward Hale 6 bus, IEEE 30 bus, 57 bus, 118 bus and 300 bus test systems. The simulation results show that the proposed approach is more suitable, effective and efficient compared to other optimization techniques presented in the literature.he size of CSD. According to the results of our study, we created an experimental full capacity layout, and its studies are also provided in this paper.
Optimal planning of RDGs in electrical distribution networks using hybrid SAP...IJECEIAES
The impact of the renewable distributed generations (RDGs), such as photovoltaic (PV) and wind turbine (WT) systems can be positive or negative on the system, based on the location and size of the DG. So, the correct location and size of DG in the distribution network remain an obstacle to achieving their full possible benefits. Therefore, the future distribution networks with the high penetration of DG power must be planned and operated to improve their efficiency. Thus, this paper presents a new methodology for integrated of renewable energy-based DG units with electrical distribution network. Since the main objective of the proposed methodology is to reduce the power losses and improve the voltage profile of the radial distribution system (RDS). In this regard, the optimization problem was formulated using loss sensitivity factor (LSF), simulated annealing (SA), particle swarm optimization (PSO) and a combination of loss sensitivity index (LSI) with SA and PSO (LSISA, LSIPSO) respectively. This paper contributes a new methodology SAPSO, which prevents the defects of SA and PSO. Optimal placement and sizing of renewable energy-based DG tested on 33-bus system. The results demonstrate the reliability and robustness of the proposed SAPSO algorithm to find the near-optimal position and size of the DG units to mitigate the power losses and improve the radial distribution system's voltage profile.
Network loss reduction and voltage improvement by optimal placement and sizin...nooriasukmaningtyas
Minimization of real power loss and improvement of voltage authenticity of
the network are amongst the key issues confronting power systems owing to
the heavy demand development problem, contingency of transmission and
distribution lines and the financial costs. The distributed generators (DG) has
become one of the strongest mitigating strategies for the network power loss
and to optimize voltage reliability over integration of capacitor banks and
network reconfiguration. This paper introduces an approach for the
optimizing the placement and sizes of different types of DGs in radial
distribution systems using a fine-tuned particle swarm optimization (PSO).
The suggested approach is evaluated on IEEE 33, IEEE 69 and a real
network in Malaysian context. Simulation results demonstrate the
productiveness of active and reactive power injection into the electric power
system and the comparison depicts that the suggested fine-tuned PSO
methodology could accomplish a significant reduction in network power loss
than the other research works.
Similar to IMPROVED SWARM INTELLIGENCE APPROACH TO MULTI OBJECTIVE ED PROBLEMS (20)
MITIGATION OF UNBALANCED FAULTS IN DISTRIBUTION SYSTEM USING FD-STATCOM WITH ...Suganthi Thangaraj
Power quality is certainly a major concern in the present era. This paper proposes a flexible D-STATCOM with a new controller scheme. And it supplies power to sensitive loads under Islanding conditions. This paper introduces the performance of FD-STATCOM system to mitigate power quality problems under all types of system related disturbances such as L-L &DLG faults. A 12 pulse IGBT based D-STATCOM is designed using MATLAB. Here the super capacitor is used as the storage device. The realibility of the control scheme in the system response to the voltage disturbances caused by LL&DLG faults and Islanded operating conditions are obviously proved in the simulation results.
ENHANCING RELIABILITY BY RECONFIGURATION OF POWER DISTRIBUTION SYSTEMS CONSID...Suganthi Thangaraj
The paper describes an effective method to reconfigure a power distribution system using optimization techniques. Here genetic algorithm is used for the reconfiguration to enhance reliability and to reduce losses. The reliability at the load points is evaluated using probabilistic reliability approach. For finding minimal cut sets and losses different algorithms are used. To maximise the reliability and to reduce the losses, the status of the switch is controlled using genetic algorithm. The effectiveness of the system is tested in 33 bus distribution system.
An Improved Differential Evolution Algorithm for Congestion Management Consid...Suganthi Thangaraj
In deregulated electricity market, Congestion Management (CM) is one of the most significant issues in order to maintain
the system in secure state and to get the reliable system operation. While addressing Congestion Management voltage
stability should also be taken into account. This paper elucidates an Improved Differential Evolution (IDE) algorithm to
alleviate Congestion in transmission line by rescheduling of generators while considering voltage stability. Differential
Evolution (DE) is one of the heuristic, population based algorithm which is well suited for solving complex and non-linear
optimization problems. A Double Best Mutation Operator (DBMO) is proposed to improve DE algorithm’s convergence
rate. In order to validate suitability of the suggested approach, it has been evaluated on the IEEE-30 bus test system on
both base case loading as well as 10% increased load. The test system has been also examined under critical line outages.
The results and discussions clearly depicts the effectiveness of the projected approach in solving Congestion Management
Problem.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
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IMPROVED SWARM INTELLIGENCE APPROACH TO MULTI OBJECTIVE ED PROBLEMS
1. C.Jeevakarunya, Mrs.S.T.Suganthi / International Journal of Engineering Research and Applications
(IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 2,Mar-Apr 2012, pp.1203-1211
1203 | P a g e
IMPROVED SWARM INTELLIGENCE APPROACH TO MULTI
OBJECTIVE ED PROBLEMS
C.Jeevakarunya*, Mrs.S.T.Suganthi**
*(M.E-Power system Engineering, Department of EEE, SNS college of Technology, Anna University, Coimbatore-2)
** (Assistant professor, Department of EEE, SNS college of Technology, Anna University, Coimbatore-2)
ABSTRACT
Electrical power industry restructuring has created highly vibrant and competitive market that altered many aspects
of the power industry. In this changed scenario, scarcity of energy resources, increasing power generation cost, environment
concern, ever growing demand for electrical energy necessitate optimal economic dispatch. Practical economic dispatch
(ED) problems have nonlinear, non-convex type objective function with intense equality and inequality constraints. The
conventional optimization methods are not able to solve such problems as due to local optimum solution convergence.
Metaheuristic optimization techniques especially Improved Particle Swarm Optimization (IPSO) has gained an incredible
recognition as the solution algorithm for such type of ED problems in last decade. The application of IPSO in ED problem,
which is considered as one of the most complex optimization problem has been summarized in present paper. This paper
illustrates successful implementation of the Improved Particle Swarm Optimization (IPSO) to Economic Load Dispatch
Problem (ELD). Power output of each generating unit and optimum fuel cost obtained using IPSO algorithm has been
compared with conventional techniques. The results obtained shows that IPSO algorithm converges to optimal fuel cost with
reduced computational time when compared to PSO and GA for the three, six and IEEE 30 bus system.
Keywords: Economic Load dispatch, Evolutionary Algorithms, GA, PSO
1. INTRODUCTION
ECONOMIC dispatch (ED) problem is one of the fundamental issues in power system operation. In essence, it is an
optimization problem and its objective is to reduce the total generation cost of units, while satisfying constraints. Previous
efforts on solving ED problems have employed various mathematical programming methods and optimization techniques.
These conventional methods include the lambda-iteration method, the base point and participation factors method, and the
gradient method. [1], [2], [18], [19].In these numerical methods for solution of ED problems, an essential assumption is that
the incremental cost curves of the units are monotonically increasing piecewise-linear functions. Unfortunately, this
assumption may render these methods infeasible because of its nonlinear characteristics in practical systems. These nonlinear
characteristics of a generator include discontinuous prohibited zones, ramp rate limits, and cost functions which are not
smooth or convex. Furthermore, for a large-scale mixed-generating system, the conventional method has oscillatory problem
resulting in a longer solution time. A dynamic programming (DP) method for solving the ED problem with valve-point
modeling had been presented by [1], [2]. However, the DP method may cause the dimensions of the ED problem to become
extremely large, thus requiring enormous computational efforts.
In order to make numerical methods more convenient for solving ED problems, artificial intelligent techniques, such as
the Hopfield neural networks, have been successfully employed to solve ED problems for units with piecewise quadratic fuel
cost functions and prohibited zones constraint [3], [4]. However, an unsuitable sigmoidal function adopted in the Hopfield
model may suffer from excessive numerical iterations, resulting in huge calculations.
In the past decade, a global optimization technique known as genetic algorithms (GA) or simulated annealing (SA),
which is a form of probabilistic heuristic algorithm, has been successfully used to solve power optimization problems such
as feeder reconfiguration and capacitor placement in a distribution system [1],[5]–[7]. The GA method is usually faster than
the SA method because the GA has parallel search techniques, which emulate natural genetic operations. Due to its high
potential for global optimization, GA has received great attention in solving ED problems. In some GA applications, many
constraints including network losses, ramp rate limits, and valve-point zone were considered for the practicability of the
proposed method. Among these, Walters and Sheble presented a GA model that employed units‘ output as the encoded
parameter of chromosome to solve an ED problem for valve-point discontinuities [5].Chen and Chang presented a GA
method that used the system incremented cost as encoded parameter for solving ED problems that can take into account
network losses, ramp rate limits, and valve-point zone [8]. Fung et al. presented an integrated parallel GA incorporating
simulated annealing (SA) and tabu search (TS) techniques that employed the generator‘s output as the encoded parameter
[9]. For an efficient GA method, Yalcinoz have used the real-coded representation scheme, arithmetic crossover, mutation,
and elitism in the GA to solve more efficiently the ED problem, and it can obtain a high-quality solution with less
computation time [10].
2. C.Jeevakarunya, Mrs.S.T.Suganthi / International Journal of Engineering Research and Applications
(IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 2,Mar-Apr 2012, pp.1203-1211
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Though the GA methods have been employed successfully to solve complex optimization problems, recent research has
identified some deficiencies in GA performance. This degradation in efficiency is apparent in applications with highly
epistatic objective functions (i.e., where the parameters being optimized are highly correlated) [the crossover and mutation
operations cannot ensure better fitness of offspring because chromosomes in the population have similar structures and their
average fitness is high toward the end of the evolutionary process] [11],[16]. Moreover, the premature convergence of GA
degrades its performance and reduces its search capability that leads to a higher probability toward obtaining a local
optimum [11].Particle swarm optimization (PSO), first introduced by Kennedy and Eberhart, is one of the
modern heuristic algorithms. It was developed through simulation of a simplified social system, and has been found to be
robust in solving continuous nonlinear optimization problems [13]–[17]. The PSO technique can generate high-quality
solutions within shorter calculation time and stable convergence characteristic than other stochastic methods [14]–[17].
Although the PSO seems to be sensitive to the tuning of some weights or parameters, many researches are still in progress
for proving its potential in solving complex power system problems [16]. Researchers including Yoshida et al. have
presented a PSO for reactive power and voltage control (VC) considering voltage security assessment. The feasibility of their
method is compared with the reactive tabu system (RTS) and enumeration method on practical power system, and has shown
promising results [18].Naka et al. have presented the use of a hybrid PSO method for solving efficiently the practical
distribution state estimation problem [19].
In this paper, a PSO method for solving the ED problem in power system is proposed. The proposed method considers
the nonlinear characteristics of a generator such as ramp rate limits and prohibited operating zone for actual power system
operation. The feasibility of the proposed method was demonstrated for three different systems [8], [20], respectively.
2. PROBLEM DESCRIPTION
The ED is one sub problem of the unit commitment (UC) problem. It is a nonlinear programming optimization one.
Practically, while the scheduled combination units at each specific period of operation are listed, the ED planning must
perform the optimal generation dispatch among the operating units to satisfy the system load demand, spinning reserve
capacity, and practical operation constraints of generators that include the ramp rate limit and the prohibited operating zone
[12].
2.1 Practical Operation Constraints of Generator
For convenience in solving the ED problem, the unit generation output is usually assumed to be adjusted smoothly and
instantaneously. Practically, the operating range of all online units is restricted by their ramp rate limits for forcing the units
operation continually between two adjacent specific operation periods [1], [2]. In addition, the prohibited operating zones in
the input-output curve of generator are due to steam valve operation or vibration in a shaft bearing. Because it is difficult to
determine the prohibited zone by actual performance testing or operating records, the best economy is achieved by avoiding
operation in areas that are in actual operation. Hence, the two constraints of generator operation must be taken into account
to achieve true economic operation.
2.1.1) Ramp Rate Limit: According to [3], [5], and [8], the inequality constraints due to ramp rate limits for unit generation
changes are given
a) As generation increases
Pi-Pi
0
≤URi (1)
b) As generation decreases
Pi-Pi
0
≤DRi (2)
Where Pi is the current output power and Pi
0
is the previous output power. URi is the up ramp limit of the i-th generator
(MW/time-period); and DRi is the down ramp limit of the i-th generator (MW/time period).
2.1.2) Prohibited Operating Zone: References [2], [3], and [8] have shown the input-output performance curve for a typical
thermal unit with many valve points. These valve points generate many prohibited zones. In practical operation, adjusting the
generation output Pi of a unit must avoid unit operation in the prohibited zones. The feasible operating zones of unit can be
described as follows:
Pi
min
≤Pi≤ Pi,1
l
(3)
Pi,j-1
u
≤Pi≤ Pi,j
l
,j=2….ni (4)
Pi, ni
u
≤ Pi,≤ Pi
max
(5)
2.2 OBJECTIVE FUNCTION
The objective of ED is to simultaneously minimize the generation cost rate and to meet the load demand of a power
system over some appropriate period while satisfying various constraints. To combine the above two constraints into a ED
problem, the constrained optimization problem at specific operating interval can be modified as
Minimize F t = = ai (Pi
2
) +bi(Pi)+ci (6)
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(IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 2,Mar-Apr 2012, pp.1203-1211
1205 | P a g e
2.2.1Constraints
i) Power balance
i=Pd + Pl (7)
ii) Generator operation constraints
max (Pi
min
, Pi
0
- DRi) ≤ Pi ≤ min( Pi
max
, Pi
0
-+URi) (8)
Pi = Pi
min
≤Pi≤ Pi,1
l
(9)
Pu
i,j-1≤Pi≤ Pi,j
l
,j=2….ni (10)
Pu
i, ni≤ Pi,≤ Pi
max
(11)
iii) Line flow constraints
PLf,k ≤ Pmax
Lf,k, k=l….L (12)
where the generation cost function Fi(Pi) is usually expressed as a quadratic polynomial; ai, bi, and ci are the cost coefficients
of the i-th generator is the number of generators committed to the operating system; Pi is the power output of the i-th
generator; PLf,k is the real power flow of line j ; k is the number of transmission lines; and the total transmission network
losses is a function of unit power outputs that can be represented using B coefficients
Pl = lmBmnPln (13)
iv) Reactive power limit
Q i
min
≤ Qi ≤ Q i
max
(14)
v) Voltage limits
Vi
min
≤ Vi ≤ Vi
max
(15)
3. OVERVIEW OF PSO
PSO is a population based stochastic optimization technique developed by Dr.Ebehart and Dr. Kennedy in 1995,
inspired by social behavior of bird flocking or fish schooling. PSO shares many similarities with evolutionary computation
techniques such as GA. The system is initialized with a population of random solutions and searches for optima by updating
generations. However, unlike GA, PSO has no evolution operators such as crossover and mutation. In PSO, the potential
solutions, called particles, fly through the problem space by following the current optimum particles. The detailed
information will be given in following sections. Compared to GA, the advantages of PSO are that PSO is easy to implement
and there are few parameters to adjust. PSO has been successfully applied in many areas like Function optimization, artificial
neural network training, fuzzy system control, and other areas where GA can be applied.
The PSO belongs to the class of direct search methods used to find an optimal solution to an objective function (aka
fitness function) in a search space. Direct search methods are usually derivative-free, meaning that they depend only on the
evaluation of the objective function. The PSO algorithm is simple, in the sense that even the basic form of the algorithm
yields results, it can be implemented by a programmer in short duration, and it can be used by anyone with an understanding
of objective functions and the problem at hand without needing an extensive background in mathematical optimization
theory. The PSO is a stochastic, population-based computer algorithm modeled on swarm intelligence. PSO is inspired by a
kind of social optimization. A problem is given, and some way to evaluate a proposed solution to it exists in the form of a
fitness function. A communication structure or social network is also defined, assigning neighbors for each individual to
interact with. Then a population of individuals defined as random guesses at the problem solutions is initialized. These
individuals are candidate solutions. They are also known as the particles, hence the name particle swarm. An iterative
process to improve these candidate solutions is set in motion. The particles iteratively evaluate the fitness of the candidate
solutions and remember the location where they had their best success. The individual's best solution is called the particle
best or the local best. Each particle makes this information available to their neighbors. They are also able to see where their
neighbors have had success. Movements through the search space are guided by these successes, with the population usually
converging, by the end of a trial, on a problem solution better than that of non-swarm approach using the same methods. The
PSO shares many similarities with evolutionary computation techniques such as GA. The system is initialized with a
population of random solutions and searches for optima by updating generations. However, unlike GA, PSO has no
evolution operators such as crossover and mutation.
PSO simulates the behaviors of bird flocking. In PSO, each single solution is a "bird" in the search space. We call it
"particle". All of particles have fitness values, which are evaluated by the fitness function to be optimized, and have
velocities, which direct the flying of the particles. The particles fly through the problem space by following the current
optimum particles. PSO is initialized with a group of random particles (solutions) and then searches for optima by updating
generations. In every iteration, each particle is updated by following two "best" values. The first one is the best solution
(fitness) it has achieved so far. (The fitness value is also stored.) This value is called pbest. Another "best" value that is
tracked by the particle swarm optimizer is the best value, obtained so far by any particle in the population. This best value is
a global best and called g-best. When a particle takes part of the population as its topological neighbors, the best value is a
local best and is called p-best. After finding the two best values, the particle updates its velocity and positions with following
equations.
4. C.Jeevakarunya, Mrs.S.T.Suganthi / International Journal of Engineering Research and Applications
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Vi
(u+1)
=W*Vi
(u)
+C1*rand()*(pbesti-Pi
(u)
)+ C2*rand()*(gbesti-Pi
(u)
) (16)
Pi
(u+1)
=Pi
(u)
+ Vi
(u+1)
(17)
In the above equation,
The term rand ( )*(pbest i -Pi
(u)
) is called particle memory influence
The term rand ( )*( gbesti -Pi
(u)
) is called swarm influence.
Vi
(u)
which is the velocity of ith particle at iteration ‗u‘ must lie in the range
Vmin ≤ Vi
(u)
≤ Vmax The parameter Vmax determines the resolution, or fitness, with which regions are to be searched
between the present position and the target position
a. If Vmax is too high, particles may fly past good solutions. If Vmin is too small, particles may not explore sufficiently
beyond local solutions.
b. In many experiences with PSO, Vmax was often set at 10-20% of the dynamic range on each dimension.
c. The constants C1and C2 pull each particle towards pbest and gbest positions.
d. Low values allow particles to roam far from the target regions before being tugged back. On the other hand, high
values result in abrupt movement towards, or past, target regions.
e. The acceleration constants C1 and C2 are often set to be 2.0 according to past experiences
f. Suitable selection of inertia weight ‘ω‘ provides a balance between global and local explorations, thus requiring less
iteration on average to find a sufficiently optimal solution.
In general, the inertia weight w is set according to the following equation,
(18)
where w -is the inertia weighting factor
Wmax - maximum value of weighting factor
Wmin - minimum value of weighting factor
ITERmax - maximum number of iterations
ITER - current number of iteration
The Equation (5.1) is used to calculate the particle's new velocity according to its previous velocity and the distances of
its current position from its own best experience (position) and the group's best experience. Then the particle flies towards a
new position according to Equation (2). The performance of each particle is measured according to a predefined fitness
function , this is related to the problem to be solved.
The step by step procedure of PSO algorithm is given as follows
a. Initialize a population of particles with random values and velocities within the d-dimensional search space.
Initialize the maximum allowable velocity magnitude of any particle Vmax. Evaluate the fitness of each particle and
assign the particle's position to pbest position and fitness to pbest fitness. Identify the best among the pbest as gbest.
b. Change the velocity and position of the particle according to Equations (5.1) and Equations (5.2) respectively.
c. For each particle, evaluate the fitness, if all decisions variables are within the search ranges.
d. Compare the particle's fitness evaluation with its previous pbest. If the current value is better than the previous
pbest, then set the pbest value equal to the current value and the pbest location equal to the current location in the d
dimensional search space.
e. Compare the best current fitness evaluation with the population gbest. If the current value is better than the
population gbest, then reset the gbest to the current best position and the fitness value to current fitness value.
f. Repeat steps 2-5 until a stopping criterion, such as sufficiently good gbest fitness or a maximum number of
iterations i function evaluations is met.
4. PSO IMPLEMENTATION TO ELD
When the losses are considered the optimization process becomes little bit complicated. Since the losses are dependent
on the power generated of the each unit, in each generation the loss changes. The P-loss can be found out by using the
equation
(19)
5. C.Jeevakarunya, Mrs.S.T.Suganthi / International Journal of Engineering Research and Applications
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Vol. 2, Issue 2,Mar-Apr 2012, pp.1203-1211
1207 | P a g e
Where Bmn are the loss co-efficient. The loss co-efficient can be calculated from the load flow equations or it may be given
in the problem. However in this work for simplicity the loss coefficient are given which are the approximate one. Some parts
are neglected.
The sequential steps to find the optimum solution are
a. The power of each unit, velocity of particles, is randomly generated which must be in the maximum and minimum
limit. These initial individuals must be feasible candidate solutions that satisfy the practical operation constraints.
b. Each set of solution in the space should satisfy the following equation
i=Pd + Pl (20)
Pl calculated by using above equation .Then equality constraints are checked. If any
c. Combination doesn‘t satisfy the constraints then they are set according to the power balance equation.
(21)
d. The cost function of each individual Pgi, is calculated in the population using the evaluation function F. Here F is
F=a*(Pgi) 2
+b*Pgi +c (22)
where a, b, c are constants. The present value is set as the pbest value.
e. Each pbest values are compared with the other pbest values in the population. The best evaluation value among the
pbest is denoted as gbest.
f. The member velocity v of each individual Pg is updated according to the velocity update equation
Vid
(u+1)
=w *Vi
(u)
+C1*rand ( )*(pbest id -Pgid
(u)
+C2*rand ( )*( gbestid -Pgid
(u)
) (23)
where u is the number of iteration.
g. The velocity components constraint occurring in the limits from the following conditions are checked
Vdmin = -0.5*Pmin (24)
Vdmax = +0.5*Pmax (25)
h. The position of each individual Pg is modified according to the position update equation
P gid
(u+1)
= P gid
(u)
+ V id
(u+1)
(26)
i. The cost function of each new is calculated If the evaluation value of each individual is better than previous pbest;
the current value is set to be pbest. If the best pbest is better than gbest, the value is set to be gbest.
j. If the number of iterations reaches the maximum, then go to step 10.Otherwise, go to step 2.
k. The individual that generates the latest gbest is the optimal generation power of each unit with the minimum total
generation cost.
5. IMPROVED SWARM INTELLIGENCE APPROACH TO ELD
Especially, most of the PSO algorithms are aimed at unconstrained problems. For the constrained problems, the
approach introduced is just the traditional combination of primitive PSO and the penalty function. It was investigated that the
simple penalty function strategy cannot be integrated well with PSO algorithms because it does not utilize the historical
memory information, which is an essential of PSO. Besides penalty functions face the difficulty of maintaining a balance
between obtaining feasibility even as finding optimality. Thus, in order to solve constrained ELD problem optimization a
new constraints handling strategy is used for improvement the optimization mechanism of PSO algorithm. The proposed
approach is called preservation of Feasible Solutions Method (FSM). This method for constraint handling with PSO was
adapted by Hu and Eberhart in [8]. In the proposed method, fitness function and constraints are handled separately. Fitness
function is used to guide search direction. Constraints are used to check the feasibility of particles. When implementing this
technique into the global version of PSO, the initialization process involves forcing all particles into the feasible space before
any evaluation of the objective function has begun. Upon evaluation of the objective function, only particles which remain in
the feasible space are counted for the new PBest and GBest values (or lBest for the local version).Although extra loops are
needed to find feasible solutions, the time complexity is not high as expected. A feasible solution has to satisfy all the
constraints. Once a constraint is not satisfied, it is not necessary to test other constraints. Thus, the overall time complexity is
not proportional to the number of needed loops and the computation time will be much less. The idea here is to accelerate the
6. C.Jeevakarunya, Mrs.S.T.Suganthi / International Journal of Engineering Research and Applications
(IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 2,Mar-Apr 2012, pp.1203-1211
1208 | P a g e
iterative process of tracking feasible solutions by forcing the search space to contain only solutions that do not violate any
constraints.
The process of the modified PSO algorithm for solution of the ELD problem can be summarized as follows:
a. Read the original data including power system data and the PSO parameters.
b. Set the generation counter t=0, Initialize randomly the particles of the population, Repeat initializing particle
until it satisfies all the constraints.
Note that it is very important to create a group of individuals satisfying the equality constraint (3) and inequality
constraints (4). i.e.: summation of all elements of individual i. P and the created element of individual at random
should be located within its boundary. Although, we can create element of individual at random satisfying the
inequality constraint by mapping [0, 1] into [Pmax-Pmin], the particles are randomly generated between the
maximum and the minimum operating limits of the generators. In the ED problems the number of online generating
units is the ‗dimension‘ of this problem. For example, if there are N units, the i th particle is represented as follows:
Pi = ( Pi1 , Pi2 , Pi3 , . . . , PiN ).
c. The particle velocities are generated randomly in the range[-Vj
max
,Vj
max
].The maximum velocity limit in the jth
dimension is computed as follows:
Vj
max=
, max , minj jX X
R
(27)
Where, R is the chosen number of intervals in the jth dimension. For all the examples tested using the PSO
approach, Vmax was set at 10–20% of the dynamic range of the variable on each dimension.
d. Calculate the evaluation value of each particle, in the population using the evaluation function (1) as initial fitness
and set initial position particles as the initial Pbest value of the particles. The initial best value among the particle
swarm is set to initial Gbest.
e. Let t=t+1.
f. update velocities and positions for all the dimensions in each particle by Eq. (16).and (17).
g. Calculate the fitness value of the new particles by power flow calculation and object function.
h. Update Pbest by using preserving feasibility strategy.If the new value is better than the previous Pbest and the
particle is in the feasible space, then the new value is set to Pbest and then selected the particle with the best Pbest
value among all the swarm as the Gbest.
i. The best value among all the Pbest values, Gbest, is identified.
j. Go to step (5) until a termination criterion is met, usually a sufficiently good fitness value or a maximum number
of generation is chosen for termination criterion.
5. SIMULATION RESULTS
The applicability and validity of the PSO algorithm for practical applications has been tested on various test cases.
The obtained best solution in fifty runs are compared with the results obtained using GA [2]. All the programs are developed
using MATLAB 7.01 and the system configuration is Intel Core 2 Duo with 4 GHz speed and 4GB RAM.
In this section, to demonstrate the effectiveness of the proposed method, the IPSO are applied to solve the three, six, and
thirty bus systems by considering the constraints of the ED problem. The simulation results are compared with PSO and GA
method reported in literature. The parameters of the IPSO such as c1 and c2 are set as 2.05, K =0.729 , Vmin =0.4, Vmax =0.9,
Table I, II, III shows the data of the test system. The best results obtained from the IPSO are compared with the PSO and
GA. The results show that the proposed approaches have high solution quality than others method as depicted. Table IV, V,
VI shows the effectiveness in term of the solution quality among 100 trials of proposed methods. The solutions of the
proposed methods higher quality than the rest methods in term of minimum cost, average cost, maximum cost,
computational time and solution deviation.
The cost coefficients and generation limits of three units system are taken from [2]. Transmission loss for this system is
calculated using matrix.
TABLE I
GENERATING UNIT CAPACITY AND COEFFICIENTS: THREE GENERATING UNIT SYSTEM
a
i
($/MWh
2
)
b
i
($/MWh)
c
i
P
min
(MW)
P
max
(MW)
0.008 7 200 10 85
0.009 6.3 180 10 80
7. C.Jeevakarunya, Mrs.S.T.Suganthi / International Journal of Engineering Research and Applications
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0.007 6.8 140 10 70
ai,bi,ci are the fuel cost coefficients and Pmax and Pmin are the real power limits.
TABLE II
SIX GENERATING UNIT SYSTEM
a
i
($/MWh
2
)
b
i
($/MWh)
c
i
P
min
(MW)
P
max
(MW)
0.0070 7 240 100 500
0.0095 10 200 50 200
0.0090 8.5 220 80 300
0.0090 11 200 50 150
0.0080 10.5 220 50 200
0.0075 12 120 50 120
TABLE III
IEEE 30 BUS SYSTEM
UNIT
S
p
i
MAX
(MW)
p
i
MIN
(MW)
a
i
($/MWh
2
)
b
i
($/MWh)
C
i
1 50 200 0.00375 2.00 0
2 20 80 0.01750 1.75 0
5 15 50 0.06250 1.00 0
8 10 35 0.00834 3.25 0
11 10 30 0.02500 3.00 0
13 12 40 0.02500 3.00 0
The results including the generation cost, and power losses are shown below. The result gives the optimum generations
for minimum total cost and seems to be efficient for solving non convex ELD problems. The IPSO algorithms were tested
and the results were presented for various test systems. Results showed that IPSO methods are well suited for obtaining the
best solution for fuel cost functions of differentiable, non smooth, and non differentiable of the test systems.
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1210 | P a g e
TABLE IV
SIMULATION RESULT FOR THREE BUS SYSTEM
TABLE V
SIMULATION RESULT FOR SIX BUS SYSTEM
IPSO PSO GA
P1(MW) 323.6373 276.2339 277.322
P2(MW) 76.685 106.1268 105.2414
P3(MW) 158.435 143.868 144.5728
P4(MW) 50.00 54.5248 55.6876
P5(MW) 51.976 80.5364 82.7985
P6(MW) 50.00 50.00 51.000
Pl(MW) 10.73541 11.29094 11.6883
F($/hr) 8352.61 8388.13 8390.93
TABLE VI
SIMULATION RESULT FOR IEEE 30 BUS SYSTEM
6. CONCLUSION
In this paper, we have successfully employed the IPSO method to solve the ELD problem with the generator constraints.
The IPSO algorithm has been demonstrated to have superior features, including high-quality solution, stable convergence
characteristic, and good computation efficiency. Many nonlinear characteristics of the generator such as ramp rate limits,
valve-point zones, and non smooth cost functions are considered for practical generator operation in the proposed method.
The results show that the proposed method was indeed capable of obtaining higher quality solution efficiently in ED
problems.
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P2(MW) 64.595 64.5435 64.0299
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Pl(MW) 2.302049 2.540060 2.678
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P
L
(MW) 8.010 8.122 9.1
F($/hr) 796.51 801.085 803.08
9. C.Jeevakarunya, Mrs.S.T.Suganthi / International Journal of Engineering Research and Applications
(IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 2,Mar-Apr 2012, pp.1203-1211
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