A micro-grid is a part of power system which able to operates in grid or islanding mode. The most important variable that able to give us information about the stability in islanded micro-grid network is the frequency dynamical responses. The frequency analysis for multi-area micro-grid network model may involve a complicated of mathematical equations. This makes the researcher intending to omit several unnecessary parameters in order to simplify the equations. The purpose of this paper is to show an approach to derive the mathematical equations to represent the average behavior of frequency dynamical responses for two different micro-grid areas. Both of networks are assumed to have non-identical distributed generator behavior with different parameters. The prime mover and speed governor systems are augmented with the general swing equation. The tie line model and the information of rotor angle was considered. Then, in the last section, the comparison between this technique with the conventional approach using centre of inertia (COI) technique was defined.
Navigation of Mobile Inverted Pendulum via Wireless control using LQR TechniqueIJMTST Journal
Mobile Inverted Pendulum (MIP) is a non-linear robotic system. Basically it is a Self-balancing robot
working on the principle of Inverted pendulum, which is a two wheel vehicle, balances itself up in the vertical
position with reference to the ground. It has four configuration variables (Cart position, Cart Velocity,
Pendulum angle, Pendulum angular velocity) to be controlled using only two control inputs. Hence it is an
Under-actuated system. This paper focuses on control of translational acceleration and deceleration of the
MIP in a dynamically reasonable manner using LQR technique. The body angle and MIP displacement are
controlled to maintain reference states where the MIP is statically unstable but dynamically stable which
leads to a constant translational acceleration due to instability of the vehicle. In this proposal, the
implementation of self balancing robot with LQR control strategy and the implementation of navigation
control of the bot using a wireless module is done. The simulation results were compared between PID control
and LQR control strategies.
Implementation of a Voltage Multiplier based on High Step-up Converter using FLCIJMTST Journal
A Front end of the Photovoltaic Solar Panel is been proposed based on Step-Up Converter. The use of
distributed energy resources is increasingly being pursued as a supplement and an alternative to large
conventional central power stations. The specification of a power electronic interface is subject to
requirements related not only to the renewable energy source itself but also to its effects on the power-system
operation, especially where the intermittent energy source constitutes a significant part of the total system
capacity. Implementing a voltage multiplier module, an asymmetrical interleaved high step-up converter
obtains high step-up gain without operating at an extreme duty ratio. The voltage multiplier module is
composed of a conventional boost converter and coupled inductors. An extra conventional boost converter is
integrated into the first phase to achieve a considerably higher voltage conversion ratio. The two-phase
configuration not only reduces the current stress through each power switch, but also constrains the input
current ripple, which decreases the conduction losses of metal–oxide–semiconductor field-effect transistors.
In addition, the proposed converter functions as an active clamp circuit, which alleviates large voltage spikes
across the power switches. Finally, the simulation circuitry with a 40V input voltage and 230V output voltage
is operated to verify its performance analysis with respect to the Fuzzy Logic Controller. The highest
efficiency is 97.75%.
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.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Modeling of the magnetizing phenomena of doubly fed induction generator using...IJECEIAES
Doubly fed Induction Generators (DFIGs) are quite common in wind energy conversion systems because of their variable speed nature and the lower rating of converters. Magnetic flux saturation in the DFIG significantly affect its behavior during transient conditions such as voltage sag, sudden change in input power and short circuit. The effect of including saturation in the DFIG modeling is significant in determining the transient performance of the generator after a disturbance. To include magnetic saturation in DFIG model, an accurate representation of the magnetization characteristics is inevitable. This paper presents a qualitative modeling for magnetization characteristics of doubly fed induction generator using neuro-fuzzy systems. Neuro-fuzzy systems with one hidden layer of Gaussian nodes are capable of approximating continuous functions with arbitrary precision. The results obtained are compared with magnetization characteristics obtained using discrete fourier transform, polynomial and exponential curve fitting. The error analysis is also done to show the effectiveness of the neuro fuzzy modeling of magnetizing characteristics. By neuro-fuzzy algorithm, fast learning convergence is observed and great performance in accuracy is achieved.
The electrical and environmental parameters of polymer solar cells (PSC) provide important information on their performance. In the present article we study the influence of temperature on the voltage-current (I-V) characteristic at different temperatures from 10 °C to 90 °C, and important parameters like bandgap energy Eg, and the energy conversion efficiency η. The one-diode electrical model, normally used for semiconductor cells, has been tested and validated for the polemeral junction. The PSC used in our study are formed by the poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM). Our technique is based on the combination of two steps; the first use the Least Mean Squares (LMS) method while the second use the Newton-Raphson algorithm. The found results are compared to other recently published works, they show that the developed approach is very accurate. This precision is proved by the minimal values of statistical errors (RMSE) and the good agreement between both the experimental data and the I-V simulated curves. The obtained results show a clear and a monotonic dependence of the cell efficiency on the studied parameters.
In a distributed generation system, divers renewable agents are connected to the low voltage 3 phase utility grid by an inverter which is used as power condition and must assurance the higher efficiency of the renewable agent. To achieve this level of efficiency, a unitary power factor between the utility grid voltages and the inverter currents is necessary, and a synchronization algorithm is required for the perfect synchronization between the 3-phase utility grid and the renewable agent. The aim of this paper is to present the optimization of the performance of a Synchronization controller for a 3-phase photovoltaic grid-connected system, assessing its accuracy under different conditions and studying their drawbacks and advantages. A grid connected photovoltaic system with a nominal power of 5 kW is used so as to assess the behavior of the synchronization algorithm when the 3 phase utility grid is affected by some disturbances such as voltage unbalances.
Navigation of Mobile Inverted Pendulum via Wireless control using LQR TechniqueIJMTST Journal
Mobile Inverted Pendulum (MIP) is a non-linear robotic system. Basically it is a Self-balancing robot
working on the principle of Inverted pendulum, which is a two wheel vehicle, balances itself up in the vertical
position with reference to the ground. It has four configuration variables (Cart position, Cart Velocity,
Pendulum angle, Pendulum angular velocity) to be controlled using only two control inputs. Hence it is an
Under-actuated system. This paper focuses on control of translational acceleration and deceleration of the
MIP in a dynamically reasonable manner using LQR technique. The body angle and MIP displacement are
controlled to maintain reference states where the MIP is statically unstable but dynamically stable which
leads to a constant translational acceleration due to instability of the vehicle. In this proposal, the
implementation of self balancing robot with LQR control strategy and the implementation of navigation
control of the bot using a wireless module is done. The simulation results were compared between PID control
and LQR control strategies.
Implementation of a Voltage Multiplier based on High Step-up Converter using FLCIJMTST Journal
A Front end of the Photovoltaic Solar Panel is been proposed based on Step-Up Converter. The use of
distributed energy resources is increasingly being pursued as a supplement and an alternative to large
conventional central power stations. The specification of a power electronic interface is subject to
requirements related not only to the renewable energy source itself but also to its effects on the power-system
operation, especially where the intermittent energy source constitutes a significant part of the total system
capacity. Implementing a voltage multiplier module, an asymmetrical interleaved high step-up converter
obtains high step-up gain without operating at an extreme duty ratio. The voltage multiplier module is
composed of a conventional boost converter and coupled inductors. An extra conventional boost converter is
integrated into the first phase to achieve a considerably higher voltage conversion ratio. The two-phase
configuration not only reduces the current stress through each power switch, but also constrains the input
current ripple, which decreases the conduction losses of metal–oxide–semiconductor field-effect transistors.
In addition, the proposed converter functions as an active clamp circuit, which alleviates large voltage spikes
across the power switches. Finally, the simulation circuitry with a 40V input voltage and 230V output voltage
is operated to verify its performance analysis with respect to the Fuzzy Logic Controller. The highest
efficiency is 97.75%.
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.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Modeling of the magnetizing phenomena of doubly fed induction generator using...IJECEIAES
Doubly fed Induction Generators (DFIGs) are quite common in wind energy conversion systems because of their variable speed nature and the lower rating of converters. Magnetic flux saturation in the DFIG significantly affect its behavior during transient conditions such as voltage sag, sudden change in input power and short circuit. The effect of including saturation in the DFIG modeling is significant in determining the transient performance of the generator after a disturbance. To include magnetic saturation in DFIG model, an accurate representation of the magnetization characteristics is inevitable. This paper presents a qualitative modeling for magnetization characteristics of doubly fed induction generator using neuro-fuzzy systems. Neuro-fuzzy systems with one hidden layer of Gaussian nodes are capable of approximating continuous functions with arbitrary precision. The results obtained are compared with magnetization characteristics obtained using discrete fourier transform, polynomial and exponential curve fitting. The error analysis is also done to show the effectiveness of the neuro fuzzy modeling of magnetizing characteristics. By neuro-fuzzy algorithm, fast learning convergence is observed and great performance in accuracy is achieved.
The electrical and environmental parameters of polymer solar cells (PSC) provide important information on their performance. In the present article we study the influence of temperature on the voltage-current (I-V) characteristic at different temperatures from 10 °C to 90 °C, and important parameters like bandgap energy Eg, and the energy conversion efficiency η. The one-diode electrical model, normally used for semiconductor cells, has been tested and validated for the polemeral junction. The PSC used in our study are formed by the poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM). Our technique is based on the combination of two steps; the first use the Least Mean Squares (LMS) method while the second use the Newton-Raphson algorithm. The found results are compared to other recently published works, they show that the developed approach is very accurate. This precision is proved by the minimal values of statistical errors (RMSE) and the good agreement between both the experimental data and the I-V simulated curves. The obtained results show a clear and a monotonic dependence of the cell efficiency on the studied parameters.
In a distributed generation system, divers renewable agents are connected to the low voltage 3 phase utility grid by an inverter which is used as power condition and must assurance the higher efficiency of the renewable agent. To achieve this level of efficiency, a unitary power factor between the utility grid voltages and the inverter currents is necessary, and a synchronization algorithm is required for the perfect synchronization between the 3-phase utility grid and the renewable agent. The aim of this paper is to present the optimization of the performance of a Synchronization controller for a 3-phase photovoltaic grid-connected system, assessing its accuracy under different conditions and studying their drawbacks and advantages. A grid connected photovoltaic system with a nominal power of 5 kW is used so as to assess the behavior of the synchronization algorithm when the 3 phase utility grid is affected by some disturbances such as voltage unbalances.
Load frequency control of a two area hybrid system consisting of a grid conne...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Application of AHP algorithm on power distribution of load shedding in island...IJECEIAES
This paper proposes a method of load shedding in a microgrid system operated in an Island Mode, which is disconnected with the main power grid and balanced loss of the electrical power. This proposed method calculates the minimum value of the shed power with reference to renewable energy sources such as wind power generator, solar energy and the ability to control the frequency of the generator to restore the frequency to the allowable range and reduce the amount of load that needs to be shed. Computing the load importance factor (LIF) using AHP algorithm supports to determine the order of which load to be shed. The damaged outcome of load shedding, thus, will be noticeably reduced. The experimental results of this proposed method is demonstrated by simulating on IEEE 16-Bus microgrid system with six power sources.
Defining Control Strategies for Micro Grids Islanded Operation with Maximum P...IAES-IJPEDS
This paper explains about an intelligent control method for the maximum
power point tracking (MPPT) of a photo voltaic system with different
temperature and insolation conditions. This method uses a fuzzy logic
controller applied to a DC-DC converter. The different steps of the design of
this controller are presented together with its simulation and the feasibility of
control methods to be adopted for the operation of a micro grid when it
becomes isolated. Normally, the micro grid operates in interconnected mode
with the medium voltage network; however, scheduled or forced isolation
can take place. In such conditions, the micro grid must have the ability to
operate stably and autonomously. An evaluation of the need of storage
devices and load to take off strategies is included in this paper. The MPPT of
a photovoltaic system for Micro Grid operaion using a Fuzzy logic control
scheme is successfully designed and simulated by using MATLAB/Simulink
Software.
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.
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
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.
Micro-Turbine Generation Control System Optimization Using Evolutionary algor...IJERA Editor
Distribution systems management is becoming an increasingly complicated issue due to the introduction of new technologies, new energy trading strategies, and new deregulated environment. In the new deregulated energy market and considering the incentives coming from the technical and economical fields, it is reasonable to consider Distributed Generation (DG) as a viable option to solve the lacking electric power supply problem. This paper presents a mathematical distribution system planning model considering three planning options to system expansion and to meet the load growth requirements with a reasonable price as well as the system power quality problems. DG is introduced as an attractive planning option in competition with voltage regulator devices and Interruptible load. This paper presents a dynamic modelling and simulation of a high speed single shaft micro-turbine generation (MTG) system for grid connected operation and shows genetic algorithm (GA) role in improvement of control system operation. The model is developed with the consideration of the main parts including: compressor-turbine, permanent magnet (PM) generator, three phase bridge rectifier and inverter. The simulation results show the capability of Genetic Algorithm for controlling MTG system. The model is developed in Mat lab / Simulink.
Wind Turbine Generator Tied To Grid Using Inverter Techniques and Its DesignsIJSRD
This paper proposes a method of using small sizes WTG of 300W low capacity turbine in small grid channel with inverter techniques. Power can be fed directly to grid by improving durability and eliminating battery usage, using WTG inverter technique. The proposed wind tied with grid by PMG includes boost converter and three phase inverter. For tracking wind speed with variations of wind power MPPT method is used. Interleaving technique is adopted for different frequency variables to improve power capacity. Final result proves WTG helps in improving wind power application as shown in simulation result.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
A Study of Shading Effect on Photovoltaic Modules with Proposed P&O Checking ...Yayah Zakaria
Sun irradiation levels and associated temperature changes are the main factors that influence the conversion of solar energy into electricity. Most energy is produced during a hot sunny day as the sun irradiation is at the maximum level and uniform throughout the solar photovoltaic (PV). However, most solar PV were frequently get shadowed, completely or partially, by the neighbouring buildings, trees and passing clouds. Consequently, the solar PV has lower voltage and current output, hence,
multiple maximum power points (MPP) are existed on the PV curve, which could cause confusion to the conventional Maximum Power Point Tracker (MPPT) to track the true MPP for the PV system. Thus, it is important to examine the impacts of partial shading on the solar PV in order to extract the maximum possible power. This paper presents a MATLAB-based modelling for simulation and experimental setup to study the I-V and P-V characteristics of a solar module under a non-uniform irradiation due to partial shading condition (PSC). Furthermore, this study is also proposed an effective method (a variable step size of P&O with checking algorithm) that is low cost and higher tracking efficiency. Thus, this study is essential in improving and evaluating any new MPPT algorithm under the PSC.
IMPROVED SWARM INTELLIGENCE APPROACH TO MULTI OBJECTIVE ED PROBLEMSSuganthi Thangaraj
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.
Comparison of backstepping, sliding mode and PID regulators for a voltage inv...IJECEIAES
In the present paper, an efficient and performant nonlinear regulator is designed for the control of the pulse width modulation (PWM) voltage inverter that can be used in a standalone photovoltaic microgrid. The main objective of our control is to produce a sinusoidal voltage output signal with amplitude and frequency that are fixed by the reference signal for different loads including linear or nonlinear types. A comparative performance study of controllers based on linear and non-linear techniques such as backstepping, sliding mode, and proportional integral derivative (PID) is developed to ensure the best choice among these three types of controllers. The performance of the system is investigated and compared under various operating conditions by simulations in the MATLAB/Simulink environment to demonstrate the effectiveness of the control methods. Our investigation shows that the backstepping controller can give better performance than the sliding mode and PID controllers. The accuracy and efficiency of the proposed backstepping controller are verified experimentally in terms of tracking objectives.
Performance analysis of various parameters by comparison of conventional pitc...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Performance analysis of various parameters by comparison of conventional pitc...eSAT Journals
Abstract This paper deals with a variable speed wind turbine coupled with a permanent magnet synchronous generator connected through a two mass drive train. This drive train is connected to synchronous generator and after the conversion process finally connected to grid and the idea of transmission over a long distance makes the use of converter necessary and at the receiving end. The inverter is used to convert it back and the inverter is designed with a proper gate signal to get the best output three phase voltages. The fuzzy logic controller is used to track generator speed with varying wind speed to optimize turbine aerodynamic efficiency in the outer speed loop. Pitch angle control of wind turbine has been used widely to reduce torque and output power variation in high rated wind speed areas .The machine side converter is designed to extract maximum power from the wind. In this work a WECS connected with grid is designed in Matlab and a Fuzzy controller is designed to improve the output and we can see the major difference in DC link voltage and reactive power in transmission line. From the outputs we can also go through the reactive power issue which system is best for inductive load or capacitive load. The simple PI system is good for capacitive load and the fuzzy system is better option for the inductive load. The results of both the system of normal controller and fuzzy controller is compared and analyzed. Key Words: Fuzzy logic controller (FLC), permanent magnet synchronous generator (PMSG), insulated gate bipolar transistor (IGBT) , Pulse width modulation (PWM), Wind energy conversion system, DC link capacitor. FACTS Flexible A.C Transmission system, PI proportional integral
Voltage and frequency control of microgrid in presence of micro-turbine inter...IJECEIAES
The active and reactive load changes have a significant impact on voltage
and frequency. In this paper, in order to stabilize the microgrid (MG) against
load variations in islanding mode, the active and reactive power of all
distributed generators (DGs), including energy storage (battery), diesel
generator, and micro-turbine, are controlled. The micro-turbine generator is
connected to MG through a three-phase to three-phase matrix converter, and
the droop control method is applied for controlling the voltage and
frequency of MG. In addition, a method is introduced for voltage and
frequency control of micro-turbines in the transition state from gridconnected mode to islanding mode. A novel switching strategy of the matrix
converter is used for converting the high-frequency output voltage of the
micro-turbine to the grid-side frequency of the utility system. Moreover,
using the switching strategy, the low-order harmonics in the output current
and voltage are not produced, and consequently, the size of the output filter
would be reduced. In fact, the suggested control strategy is load-independent
and has no frequency conversion restrictions. The proposed approach for
voltage and frequency regulation demonstrates exceptional performance and
favorable response across various load alteration scenarios. The suggested
strategy is examined in several scenarios in the MG test systems, and the
simulation results are addressed.
Load frequency control of a two area hybrid system consisting of a grid conne...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Application of AHP algorithm on power distribution of load shedding in island...IJECEIAES
This paper proposes a method of load shedding in a microgrid system operated in an Island Mode, which is disconnected with the main power grid and balanced loss of the electrical power. This proposed method calculates the minimum value of the shed power with reference to renewable energy sources such as wind power generator, solar energy and the ability to control the frequency of the generator to restore the frequency to the allowable range and reduce the amount of load that needs to be shed. Computing the load importance factor (LIF) using AHP algorithm supports to determine the order of which load to be shed. The damaged outcome of load shedding, thus, will be noticeably reduced. The experimental results of this proposed method is demonstrated by simulating on IEEE 16-Bus microgrid system with six power sources.
Defining Control Strategies for Micro Grids Islanded Operation with Maximum P...IAES-IJPEDS
This paper explains about an intelligent control method for the maximum
power point tracking (MPPT) of a photo voltaic system with different
temperature and insolation conditions. This method uses a fuzzy logic
controller applied to a DC-DC converter. The different steps of the design of
this controller are presented together with its simulation and the feasibility of
control methods to be adopted for the operation of a micro grid when it
becomes isolated. Normally, the micro grid operates in interconnected mode
with the medium voltage network; however, scheduled or forced isolation
can take place. In such conditions, the micro grid must have the ability to
operate stably and autonomously. An evaluation of the need of storage
devices and load to take off strategies is included in this paper. The MPPT of
a photovoltaic system for Micro Grid operaion using a Fuzzy logic control
scheme is successfully designed and simulated by using MATLAB/Simulink
Software.
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.
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
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.
Micro-Turbine Generation Control System Optimization Using Evolutionary algor...IJERA Editor
Distribution systems management is becoming an increasingly complicated issue due to the introduction of new technologies, new energy trading strategies, and new deregulated environment. In the new deregulated energy market and considering the incentives coming from the technical and economical fields, it is reasonable to consider Distributed Generation (DG) as a viable option to solve the lacking electric power supply problem. This paper presents a mathematical distribution system planning model considering three planning options to system expansion and to meet the load growth requirements with a reasonable price as well as the system power quality problems. DG is introduced as an attractive planning option in competition with voltage regulator devices and Interruptible load. This paper presents a dynamic modelling and simulation of a high speed single shaft micro-turbine generation (MTG) system for grid connected operation and shows genetic algorithm (GA) role in improvement of control system operation. The model is developed with the consideration of the main parts including: compressor-turbine, permanent magnet (PM) generator, three phase bridge rectifier and inverter. The simulation results show the capability of Genetic Algorithm for controlling MTG system. The model is developed in Mat lab / Simulink.
Wind Turbine Generator Tied To Grid Using Inverter Techniques and Its DesignsIJSRD
This paper proposes a method of using small sizes WTG of 300W low capacity turbine in small grid channel with inverter techniques. Power can be fed directly to grid by improving durability and eliminating battery usage, using WTG inverter technique. The proposed wind tied with grid by PMG includes boost converter and three phase inverter. For tracking wind speed with variations of wind power MPPT method is used. Interleaving technique is adopted for different frequency variables to improve power capacity. Final result proves WTG helps in improving wind power application as shown in simulation result.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
A Study of Shading Effect on Photovoltaic Modules with Proposed P&O Checking ...Yayah Zakaria
Sun irradiation levels and associated temperature changes are the main factors that influence the conversion of solar energy into electricity. Most energy is produced during a hot sunny day as the sun irradiation is at the maximum level and uniform throughout the solar photovoltaic (PV). However, most solar PV were frequently get shadowed, completely or partially, by the neighbouring buildings, trees and passing clouds. Consequently, the solar PV has lower voltage and current output, hence,
multiple maximum power points (MPP) are existed on the PV curve, which could cause confusion to the conventional Maximum Power Point Tracker (MPPT) to track the true MPP for the PV system. Thus, it is important to examine the impacts of partial shading on the solar PV in order to extract the maximum possible power. This paper presents a MATLAB-based modelling for simulation and experimental setup to study the I-V and P-V characteristics of a solar module under a non-uniform irradiation due to partial shading condition (PSC). Furthermore, this study is also proposed an effective method (a variable step size of P&O with checking algorithm) that is low cost and higher tracking efficiency. Thus, this study is essential in improving and evaluating any new MPPT algorithm under the PSC.
IMPROVED SWARM INTELLIGENCE APPROACH TO MULTI OBJECTIVE ED PROBLEMSSuganthi Thangaraj
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.
Comparison of backstepping, sliding mode and PID regulators for a voltage inv...IJECEIAES
In the present paper, an efficient and performant nonlinear regulator is designed for the control of the pulse width modulation (PWM) voltage inverter that can be used in a standalone photovoltaic microgrid. The main objective of our control is to produce a sinusoidal voltage output signal with amplitude and frequency that are fixed by the reference signal for different loads including linear or nonlinear types. A comparative performance study of controllers based on linear and non-linear techniques such as backstepping, sliding mode, and proportional integral derivative (PID) is developed to ensure the best choice among these three types of controllers. The performance of the system is investigated and compared under various operating conditions by simulations in the MATLAB/Simulink environment to demonstrate the effectiveness of the control methods. Our investigation shows that the backstepping controller can give better performance than the sliding mode and PID controllers. The accuracy and efficiency of the proposed backstepping controller are verified experimentally in terms of tracking objectives.
Performance analysis of various parameters by comparison of conventional pitc...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Performance analysis of various parameters by comparison of conventional pitc...eSAT Journals
Abstract This paper deals with a variable speed wind turbine coupled with a permanent magnet synchronous generator connected through a two mass drive train. This drive train is connected to synchronous generator and after the conversion process finally connected to grid and the idea of transmission over a long distance makes the use of converter necessary and at the receiving end. The inverter is used to convert it back and the inverter is designed with a proper gate signal to get the best output three phase voltages. The fuzzy logic controller is used to track generator speed with varying wind speed to optimize turbine aerodynamic efficiency in the outer speed loop. Pitch angle control of wind turbine has been used widely to reduce torque and output power variation in high rated wind speed areas .The machine side converter is designed to extract maximum power from the wind. In this work a WECS connected with grid is designed in Matlab and a Fuzzy controller is designed to improve the output and we can see the major difference in DC link voltage and reactive power in transmission line. From the outputs we can also go through the reactive power issue which system is best for inductive load or capacitive load. The simple PI system is good for capacitive load and the fuzzy system is better option for the inductive load. The results of both the system of normal controller and fuzzy controller is compared and analyzed. Key Words: Fuzzy logic controller (FLC), permanent magnet synchronous generator (PMSG), insulated gate bipolar transistor (IGBT) , Pulse width modulation (PWM), Wind energy conversion system, DC link capacitor. FACTS Flexible A.C Transmission system, PI proportional integral
Voltage and frequency control of microgrid in presence of micro-turbine inter...IJECEIAES
The active and reactive load changes have a significant impact on voltage
and frequency. In this paper, in order to stabilize the microgrid (MG) against
load variations in islanding mode, the active and reactive power of all
distributed generators (DGs), including energy storage (battery), diesel
generator, and micro-turbine, are controlled. The micro-turbine generator is
connected to MG through a three-phase to three-phase matrix converter, and
the droop control method is applied for controlling the voltage and
frequency of MG. In addition, a method is introduced for voltage and
frequency control of micro-turbines in the transition state from gridconnected mode to islanding mode. A novel switching strategy of the matrix
converter is used for converting the high-frequency output voltage of the
micro-turbine to the grid-side frequency of the utility system. Moreover,
using the switching strategy, the low-order harmonics in the output current
and voltage are not produced, and consequently, the size of the output filter
would be reduced. In fact, the suggested control strategy is load-independent
and has no frequency conversion restrictions. The proposed approach for
voltage and frequency regulation demonstrates exceptional performance and
favorable response across various load alteration scenarios. The suggested
strategy is examined in several scenarios in the MG test systems, and the
simulation results are addressed.
This paper presents a thorough control structure of the distributed generators inside the microgrid during both grid-connected and islanded operation modes. These control structures of the DGs voltage source inverters are implemented in synchronous reference frame (SRF) and controlled using linear PI controllers. By implementing the control structures, the desired real and reactive power can be efficiently transferred to the local loads and the utility load by the microgrid generating units. A modified droop control technique is introduced to facilitate the microgrid performance during both modes of operation. The active and reactive power sharing of the load demand between the utility grid and the microgrid can be performed by this drop control technique during the islanded mode. The system performance during intentional islanding event and utility load increase is investigated. The effectiveness of the offered control structures is confirmed through simulation results during both modes of operation.
Droop control method for parallel dc converters used in standalone pv wind po...eSAT Journals
Abstract The rising rate of consumption and price of fossil fuel along with environmental pollution by conventional power generation draw global attention to renewable energy sources and technology. Paper gives analysis study on current sharing issues of parallel DC converters in standalone photovoltaic (PV) WIND system. Solar wind power generating system with maximum power point tracking (MPPT) technique – incremental conductance method is used for the simulation analysis. The main drawbacks of parallel converters used in system are poor power sharing and voltage drop. The paper describes about instantaneous droop calculation considering effect of cable resistance using droop index to improve the power sharing performance. The control technique is simulated using MATLAB/SIMULINK in PV- wind power generating system with MPPT and case study has been done on the control strategy and verifies the effectiveness of adaptive droop control on output converter voltage. Key Words: Microgrid; droop method; incremental conductance (Incond); maximum power point tracking (MPPT).
Voltage Support and Reactive Power Control in Micro-grid using DGIJMER
Distribution Generators(DGs) are the renewable energy resource which can be connected to
the grid. When it is connected to the grid it should be operated with controlled voltage and reactive
power control. And in autonomous mode(i.e disconnected mode) it should operate in backup generation
mode. These DGs are connected towards the micro grid operation. The proposed control system
facilitates flexible and robust DG operational characteristics such as active/reactive power (PQ) or
active power/voltage (PV) bus operation in the grid- connected mode, regulated power control in
autonomous micro-grid mode, smooth transition between autonomous mode and PV or PQ grid
connected modes and vice versa, reduced voltage distortion under heavily nonlinear loading conditions,
and robust control performance under islanding detection delays. Evaluation results are presented to
demonstrate the flexibility and effectiveness of the proposed controller
This work includes the establishment of a Photovoltaic system connected to the grid by means of an inverter. The fundamental goal of the work is to incorporate an advanced active power flow management scheme in order to adopt load at any weather condition along with the advantage of maximum active power flow and zero harmonics from PV inverter to the grid. The outcome of analysis and control design of grid connected PV inverter using a Proportional-Integral (PI) control technique is based on synchronous dq rotating reference frame so as to achieve maximum output voltage and record the active power. It has been observed that the model provides a better rate of stability as compared to the existing topology.
4.power quality improvement in dg system using shunt active filterEditorJST
Injection of power generated by the wind turbine system into an electric grid mainly effects the power quality. The performance of this wind turbine and its power quality is determined on the basis of its measurement of power ratings as per IEEE standards. The influence of the wind turbine in the grid system concerning the power quality measurements are the active power, reactive power, variation of voltage, flicker, harmonics, and electrical behavior of switching operation. To mitigate the power quality problems this paper proposes the shunt compensator techniques. Here, the proposed system is verified experimentally using both STATCOM and TSC compensators. This control schemes for grid connected wind energy system is simulated using Matlab/Simulink.
Grid Interconnection of Renewable Energy Sources at the Distribution Level Wi...Pradeep Avanigadda
Renewable energy resources (RES) are being increasingly
connected in distribution systems utilizing power electronic
converters. This paper presents a novel control strategy for
achieving maximum benefits from these grid-interfacing inverters
when installed in 3-phase 4-wire distribution systems. The inverter
is controlled to perform as a multi-function device by incorporating
active power filter functionality. The inverter can thus be
utilized as: 1) power converter to inject power generated from
RES to the grid, and 2) shunt APF to compensate current unbalance,
load current harmonics, load reactive power demand and
load neutral current. All of these functions may be accomplished
either individually or simultaneously. With such a control, the
combination of grid-interfacing inverter and the 3-phase 4-wire
linear/non-linear unbalanced load at point of common coupling
appears as balanced linear load to the grid. This new control
concept is demonstrated with extensive MATLAB/Simulink simulation
studies and validated through digital signal processor-based
laboratory experimental results.
Index Terms—Active power filter
Modeling and Simulation of Wind Energy Conversion System Interconnected with ...idescitation
The global electrical energy consumption is steadily rising and consequently there
is a demand to increase the power generation capacity. A significant percentage of the
required capacity increase can be based on renewable energy sources.The integration of
Distributed Generations into grid has a great importance in improving system reliability.
The power generation with renewable energy sources is essential in now-a-days to control
the atmospheric pollution and global warming. To get fast tracking for maximum power, it
is preferable to use incremental conductance method. MPPT control for variable speed
wind turbine is driven by Induction Generator. The wind turbine generator is operated
such that the rotor speed varies according to wind speed to adjust the duty cycle of power
inverter and maximizes wind energy conversion system efficiency. The system includes the
wind turbine, induction generator, three phase rectifier, DC link voltage controller, three
phase inverter. In this paper, modeling and simulation of wind energy conversion system
(WECS) with incremental conductance maximum power point tracking (MPPT) is
presented. This WECS is connected to electric utility to measure the performance. In this
paper, the objective such as optimal location and sizing of DG units are studied to check the
system performance in reducing the power losses, increase in voltage profile and reliability.
For analyzing the performance of WECS, a case study is carried out on IEEE 15 bus radial
distribution system. The case studies shows that there is gradual improvement in voltage
profile, reduction in power losses and variation in reliability indices and results were
simulated in the MATLAB/SIMULINK. The results shown in this paper can contribute well
to electrical utilities with radial distribution systems.
STATCOM Based Wind Energy System by using Hybrid Fuzzy Logic ControllerIJMTST Journal
The influence of the hybrid system in the grid system concerning the power quality measurements are the active power, reactive power, voltage deviation, flicker, harmonics, and electrical behavior of switching operation and these are measured according to International Electro-Technical Commission (IEC). The STATCOM provides reactive power support to hybrid system and load. These voltage fluctuations can be eliminated with the help of advanced reactive power compensator device such as SVC and STATCOM. This work focus on design, modeling and analysis of FACTS device in wind farm interconnected with grid during fault. These devices can be controlled by Synchronous Reference Frame theory. The performance is analyzed with the help of PI controller and Fuzzy logic technique. by using Matlab/Simulink Model.
Optimal parameters of inverter-based microgrid to improve transient response IJECEIAES
The inertia issues in a microgrid can be improved by modifying the inverter control strategies to represent a virtual inertia simulation. This method employs the droop control strategy commonly used to share the power of a load among different power sources in the microgrid. This paper utilizes a modified droop control that represents this virtual inertia and applies an optimization algorithm to determine the optimal parameters and improve transient response. The results show better control when different variations are presented in the loads, leading the microgrid to have a better control of the operation. The optimization method applied in this research allows improvement to the transient response, thus avoiding unnecessary blackouts in the microgrid.
Similar to Average dynamical frequency behaviour for multi-area islanded micro-grid networks (20)
Amazon products reviews classification based on machine learning, deep learni...TELKOMNIKA JOURNAL
In recent times, the trend of online shopping through e-commerce stores and websites has grown to a huge extent. Whenever a product is purchased on an e-commerce platform, people leave their reviews about the product. These reviews are very helpful for the store owners and the product’s manufacturers for the betterment of their work process as well as product quality. An automated system is proposed in this work that operates on two datasets D1 and D2 obtained from Amazon. After certain preprocessing steps, N-gram and word embedding-based features are extracted using term frequency-inverse document frequency (TF-IDF), bag of words (BoW) and global vectors (GloVe), and Word2vec, respectively. Four machine learning (ML) models support vector machines (SVM), logistic regression (RF), logistic regression (LR), multinomial Naïve Bayes (MNB), two deep learning (DL) models convolutional neural network (CNN), long-short term memory (LSTM), and standalone bidirectional encoder representations (BERT) are used to classify reviews as either positive or negative. The results obtained by the standard ML, DL models and BERT are evaluated using certain performance evaluation measures. BERT turns out to be the best-performing model in the case of D1 with an accuracy of 90% on features derived by word embedding models while the CNN provides the best accuracy of 97% upon word embedding features in the case of D2. The proposed model shows better overall performance on D2 as compared to D1.
Design, simulation, and analysis of microstrip patch antenna for wireless app...TELKOMNIKA JOURNAL
In this study, a microstrip patch antenna that works at 3.6 GHz was built and tested to see how well it works. In this work, Rogers RT/Duroid 5880 has been used as the substrate material, with a dielectric permittivity of 2.2 and a thickness of 0.3451 mm; it serves as the base for the examined antenna. The computer simulation technology (CST) studio suite is utilized to show the recommended antenna design. The goal of this study was to get a more extensive transmission capacity, a lower voltage standing wave ratio (VSWR), and a lower return loss, but the main goal was to get a higher gain, directivity, and efficiency. After simulation, the return loss, gain, directivity, bandwidth, and efficiency of the supplied antenna are found to be -17.626 dB, 9.671 dBi, 9.924 dBi, 0.2 GHz, and 97.45%, respectively. Besides, the recreation uncovered that the transfer speed side-lobe level at phi was much better than those of the earlier works, at -28.8 dB, respectively. Thus, it makes a solid contender for remote innovation and more robust communication.
Design and simulation an optimal enhanced PI controller for congestion avoida...TELKOMNIKA JOURNAL
In this paper, snake optimization algorithm (SOA) is used to find the optimal gains of an enhanced controller for controlling congestion problem in computer networks. M-file and Simulink platform is adopted to evaluate the response of the active queue management (AQM) system, a comparison with two classical controllers is done, all tuned gains of controllers are obtained using SOA method and the fitness function chose to monitor the system performance is the integral time absolute error (ITAE). Transient analysis and robust analysis is used to show the proposed controller performance, two robustness tests are applied to the AQM system, one is done by varying the size of queue value in different period and the other test is done by changing the number of transmission control protocol (TCP) sessions with a value of ± 20% from its original value. The simulation results reflect a stable and robust behavior and best performance is appeared clearly to achieve the desired queue size without any noise or any transmission problems.
Improving the detection of intrusion in vehicular ad-hoc networks with modifi...TELKOMNIKA JOURNAL
Vehicular ad-hoc networks (VANETs) are wireless-equipped vehicles that form networks along the road. The security of this network has been a major challenge. The identity-based cryptosystem (IBC) previously used to secure the networks suffers from membership authentication security features. This paper focuses on improving the detection of intruders in VANETs with a modified identity-based cryptosystem (MIBC). The MIBC is developed using a non-singular elliptic curve with Lagrange interpolation. The public key of vehicles and roadside units on the network are derived from number plates and location identification numbers, respectively. Pseudo-identities are used to mask the real identity of users to preserve their privacy. The membership authentication mechanism ensures that only valid and authenticated members of the network are allowed to join the network. The performance of the MIBC is evaluated using intrusion detection ratio (IDR) and computation time (CT) and then validated with the existing IBC. The result obtained shows that the MIBC recorded an IDR of 99.3% against 94.3% obtained for the existing identity-based cryptosystem (EIBC) for 140 unregistered vehicles attempting to intrude on the network. The MIBC shows lower CT values of 1.17 ms against 1.70 ms for EIBC. The MIBC can be used to improve the security of VANETs.
Conceptual model of internet banking adoption with perceived risk and trust f...TELKOMNIKA JOURNAL
Understanding the primary factors of internet banking (IB) acceptance is critical for both banks and users; nevertheless, our knowledge of the role of users’ perceived risk and trust in IB adoption is limited. As a result, we develop a conceptual model by incorporating perceived risk and trust into the technology acceptance model (TAM) theory toward the IB. The proper research emphasized that the most essential component in explaining IB adoption behavior is behavioral intention to use IB adoption. TAM is helpful for figuring out how elements that affect IB adoption are connected to one another. According to previous literature on IB and the use of such technology in Iraq, one has to choose a theoretical foundation that may justify the acceptance of IB from the customer’s perspective. The conceptual model was therefore constructed using the TAM as a foundation. Furthermore, perceived risk and trust were added to the TAM dimensions as external factors. The key objective of this work was to extend the TAM to construct a conceptual model for IB adoption and to get sufficient theoretical support from the existing literature for the essential elements and their relationships in order to unearth new insights about factors responsible for IB adoption.
Efficient combined fuzzy logic and LMS algorithm for smart antennaTELKOMNIKA JOURNAL
The smart antennas are broadly used in wireless communication. The least mean square (LMS) algorithm is a procedure that is concerned in controlling the smart antenna pattern to accommodate specified requirements such as steering the beam toward the desired signal, in addition to placing the deep nulls in the direction of unwanted signals. The conventional LMS (C-LMS) has some drawbacks like slow convergence speed besides high steady state fluctuation error. To overcome these shortcomings, the present paper adopts an adaptive fuzzy control step size least mean square (FC-LMS) algorithm to adjust its step size. Computer simulation outcomes illustrate that the given model has fast convergence rate as well as low mean square error steady state.
Design and implementation of a LoRa-based system for warning of forest fireTELKOMNIKA JOURNAL
This paper presents the design and implementation of a forest fire monitoring and warning system based on long range (LoRa) technology, a novel ultra-low power consumption and long-range wireless communication technology for remote sensing applications. The proposed system includes a wireless sensor network that records environmental parameters such as temperature, humidity, wind speed, and carbon dioxide (CO2) concentration in the air, as well as taking infrared photos.The data collected at each sensor node will be transmitted to the gateway via LoRa wireless transmission. Data will be collected, processed, and uploaded to a cloud database at the gateway. An Android smartphone application that allows anyone to easily view the recorded data has been developed. When a fire is detected, the system will sound a siren and send a warning message to the responsible personnel, instructing them to take appropriate action. Experiments in Tram Chim Park, Vietnam, have been conducted to verify and evaluate the operation of the system.
Wavelet-based sensing technique in cognitive radio networkTELKOMNIKA JOURNAL
Cognitive radio is a smart radio that can change its transmitter parameter based on interaction with the environment in which it operates. The demand for frequency spectrum is growing due to a big data issue as many Internet of Things (IoT) devices are in the network. Based on previous research, most frequency spectrum was used, but some spectrums were not used, called spectrum hole. Energy detection is one of the spectrum sensing methods that has been frequently used since it is easy to use and does not require license users to have any prior signal understanding. But this technique is incapable of detecting at low signal-to-noise ratio (SNR) levels. Therefore, the wavelet-based sensing is proposed to overcome this issue and detect spectrum holes. The main objective of this work is to evaluate the performance of wavelet-based sensing and compare it with the energy detection technique. The findings show that the percentage of detection in wavelet-based sensing is 83% higher than energy detection performance. This result indicates that the wavelet-based sensing has higher precision in detection and the interference towards primary user can be decreased.
A novel compact dual-band bandstop filter with enhanced rejection bandsTELKOMNIKA JOURNAL
In this paper, we present the design of a new wide dual-band bandstop filter (DBBSF) using nonuniform transmission lines. The method used to design this filter is to replace conventional uniform transmission lines with nonuniform lines governed by a truncated Fourier series. Based on how impedances are profiled in the proposed DBBSF structure, the fractional bandwidths of the two 10 dB-down rejection bands are widened to 39.72% and 52.63%, respectively, and the physical size has been reduced compared to that of the filter with the uniform transmission lines. The results of the electromagnetic (EM) simulation support the obtained analytical response and show an improved frequency behavior.
Deep learning approach to DDoS attack with imbalanced data at the application...TELKOMNIKA JOURNAL
A distributed denial of service (DDoS) attack is where one or more computers attack or target a server computer, by flooding internet traffic to the server. As a result, the server cannot be accessed by legitimate users. A result of this attack causes enormous losses for a company because it can reduce the level of user trust, and reduce the company’s reputation to lose customers due to downtime. One of the services at the application layer that can be accessed by users is a web-based lightweight directory access protocol (LDAP) service that can provide safe and easy services to access directory applications. We used a deep learning approach to detect DDoS attacks on the CICDDoS 2019 dataset on a complex computer network at the application layer to get fast and accurate results for dealing with unbalanced data. Based on the results obtained, it is observed that DDoS attack detection using a deep learning approach on imbalanced data performs better when implemented using synthetic minority oversampling technique (SMOTE) method for binary classes. On the other hand, the proposed deep learning approach performs better for detecting DDoS attacks in multiclass when implemented using the adaptive synthetic (ADASYN) method.
The appearance of uncertainties and disturbances often effects the characteristics of either linear or nonlinear systems. Plus, the stabilization process may be deteriorated thus incurring a catastrophic effect to the system performance. As such, this manuscript addresses the concept of matching condition for the systems that are suffering from miss-match uncertainties and exogeneous disturbances. The perturbation towards the system at hand is assumed to be known and unbounded. To reach this outcome, uncertainties and their classifications are reviewed thoroughly. The structural matching condition is proposed and tabulated in the proposition 1. Two types of mathematical expressions are presented to distinguish the system with matched uncertainty and the system with miss-matched uncertainty. Lastly, two-dimensional numerical expressions are provided to practice the proposed proposition. The outcome shows that matching condition has the ability to change the system to a design-friendly model for asymptotic stabilization.
Implementation of FinFET technology based low power 4×4 Wallace tree multipli...TELKOMNIKA JOURNAL
Many systems, including digital signal processors, finite impulse response (FIR) filters, application-specific integrated circuits, and microprocessors, use multipliers. The demand for low power multipliers is gradually rising day by day in the current technological trend. In this study, we describe a 4×4 Wallace multiplier based on a carry select adder (CSA) that uses less power and has a better power delay product than existing multipliers. HSPICE tool at 16 nm technology is used to simulate the results. In comparison to the traditional CSA-based multiplier, which has a power consumption of 1.7 µW and power delay product (PDP) of 57.3 fJ, the results demonstrate that the Wallace multiplier design employing CSA with first zero finding logic (FZF) logic has the lowest power consumption of 1.4 µW and PDP of 27.5 fJ.
Evaluation of the weighted-overlap add model with massive MIMO in a 5G systemTELKOMNIKA JOURNAL
The flaw in 5G orthogonal frequency division multiplexing (OFDM) becomes apparent in high-speed situations. Because the doppler effect causes frequency shifts, the orthogonality of OFDM subcarriers is broken, lowering both their bit error rate (BER) and throughput output. As part of this research, we use a novel design that combines massive multiple input multiple output (MIMO) and weighted overlap and add (WOLA) to improve the performance of 5G systems. To determine which design is superior, throughput and BER are calculated for both the proposed design and OFDM. The results of the improved system show a massive improvement in performance ver the conventional system and significant improvements with massive MIMO, including the best throughput and BER. When compared to conventional systems, the improved system has a throughput that is around 22% higher and the best performance in terms of BER, but it still has around 25% less error than OFDM.
Reflector antenna design in different frequencies using frequency selective s...TELKOMNIKA JOURNAL
In this study, it is aimed to obtain two different asymmetric radiation patterns obtained from antennas in the shape of the cross-section of a parabolic reflector (fan blade type antennas) and antennas with cosecant-square radiation characteristics at two different frequencies from a single antenna. For this purpose, firstly, a fan blade type antenna design will be made, and then the reflective surface of this antenna will be completed to the shape of the reflective surface of the antenna with the cosecant-square radiation characteristic with the frequency selective surface designed to provide the characteristics suitable for the purpose. The frequency selective surface designed and it provides the perfect transmission as possible at 4 GHz operating frequency, while it will act as a band-quenching filter for electromagnetic waves at 5 GHz operating frequency and will be a reflective surface. Thanks to this frequency selective surface to be used as a reflective surface in the antenna, a fan blade type radiation characteristic at 4 GHz operating frequency will be obtained, while a cosecant-square radiation characteristic at 5 GHz operating frequency will be obtained.
Reagentless iron detection in water based on unclad fiber optical sensorTELKOMNIKA JOURNAL
A simple and low-cost fiber based optical sensor for iron detection is demonstrated in this paper. The sensor head consist of an unclad optical fiber with the unclad length of 1 cm and it has a straight structure. Results obtained shows a linear relationship between the output light intensity and iron concentration, illustrating the functionality of this iron optical sensor. Based on the experimental results, the sensitivity and linearity are achieved at 0.0328/ppm and 0.9824 respectively at the wavelength of 690 nm. With the same wavelength, other performance parameters are also studied. Resolution and limit of detection (LOD) are found to be 0.3049 ppm and 0.0755 ppm correspondingly. This iron sensor is advantageous in that it does not require any reagent for detection, enabling it to be simpler and cost-effective in the implementation of the iron sensing.
Impact of CuS counter electrode calcination temperature on quantum dot sensit...TELKOMNIKA JOURNAL
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
A progressive learning for structural tolerance online sequential extreme lea...TELKOMNIKA JOURNAL
This article discusses the progressive learning for structural tolerance online sequential extreme learning machine (PSTOS-ELM). PSTOS-ELM can save robust accuracy while updating the new data and the new class data on the online training situation. The robustness accuracy arises from using the householder block exact QR decomposition recursive least squares (HBQRD-RLS) of the PSTOS-ELM. This method is suitable for applications that have data streaming and often have new class data. Our experiment compares the PSTOS-ELM accuracy and accuracy robustness while data is updating with the batch-extreme learning machine (ELM) and structural tolerance online sequential extreme learning machine (STOS-ELM) that both must retrain the data in a new class data case. The experimental results show that PSTOS-ELM has accuracy and robustness comparable to ELM and STOS-ELM while also can update new class data immediately.
Electroencephalography-based brain-computer interface using neural networksTELKOMNIKA JOURNAL
This study aimed to develop a brain-computer interface that can control an electric wheelchair using electroencephalography (EEG) signals. First, we used the Mind Wave Mobile 2 device to capture raw EEG signals from the surface of the scalp. The signals were transformed into the frequency domain using fast Fourier transform (FFT) and filtered to monitor changes in attention and relaxation. Next, we performed time and frequency domain analyses to identify features for five eye gestures: opened, closed, blink per second, double blink, and lookup. The base state was the opened-eyes gesture, and we compared the features of the remaining four action gestures to the base state to identify potential gestures. We then built a multilayer neural network to classify these features into five signals that control the wheelchair’s movement. Finally, we designed an experimental wheelchair system to test the effectiveness of the proposed approach. The results demonstrate that the EEG classification was highly accurate and computationally efficient. Moreover, the average performance of the brain-controlled wheelchair system was over 75% across different individuals, which suggests the feasibility of this approach.
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For image segmentation, level set models are frequently employed. It offer best solution to overcome the main limitations of deformable parametric models. However, the challenge when applying those models in medical images stills deal with removing blurs in image edges which directly affects the edge indicator function, leads to not adaptively segmenting images and causes a wrong analysis of pathologies wich prevents to conclude a correct diagnosis. To overcome such issues, an effective process is suggested by simultaneously modelling and solving systems’ two-dimensional partial differential equations (PDE). The first PDE equation allows restoration using Euler’s equation similar to an anisotropic smoothing based on a regularized Perona and Malik filter that eliminates noise while preserving edge information in accordance with detected contours in the second equation that segments the image based on the first equation solutions. This approach allows developing a new algorithm which overcome the studied model drawbacks. Results of the proposed method give clear segments that can be applied to any application. Experiments on many medical images in particular blurry images with high information losses, demonstrate that the developed approach produces superior segmentation results in terms of quantity and quality compared to other models already presented in previeous works.
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Drug addiction is a complex neurobiological disorder that necessitates comprehensive treatment of both the body and mind. It is categorized as a brain disorder due to its impact on the brain. Various methods such as electroencephalography (EEG), functional magnetic resonance imaging (FMRI), and magnetoencephalography (MEG) can capture brain activities and structures. EEG signals provide valuable insights into neurological disorders, including drug addiction. Accurate classification of drug addiction from EEG signals relies on appropriate features and channel selection. Choosing the right EEG channels is essential to reduce computational costs and mitigate the risk of overfitting associated with using all available channels. To address the challenge of optimal channel selection in addiction detection from EEG signals, this work employs the shuffled frog leaping algorithm (SFLA). SFLA facilitates the selection of appropriate channels, leading to improved accuracy. Wavelet features extracted from the selected input channel signals are then analyzed using various machine learning classifiers to detect addiction. Experimental results indicate that after selecting features from the appropriate channels, classification accuracy significantly increased across all classifiers. Particularly, the multi-layer perceptron (MLP) classifier combined with SFLA demonstrated a remarkable accuracy improvement of 15.78% while reducing time complexity.
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It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
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Average dynamical frequency behaviour for multi-area islanded micro-grid networks
1. TELKOMNIKA Telecommunication, Computing, Electronics and Control
Vol. 18, No. 6, December 2020, pp. 3324~3330
ISSN: 1693-6930, accredited First Grade by Kemenristekdikti, Decree No: 21/E/KPT/2018
DOI: 10.12928/TELKOMNIKA.v18i6.16805 3324
Journal homepage: http://journal.uad.ac.id/index.php/TELKOMNIKA
Average dynamical frequency behaviour for multi-area islanded
micro-grid networks
M. Saifuzam Jamri, Muhammad Nizam Kamarudin, Mohd Luqman Mohd Jamil
Centre for Robotics and Industrial Automation (CeRIA), Faculty of Electrical Engineering,
Universiti Teknikal Malaysia Melaka, Malaysia
Article Info ABSTRACT
Article history:
Received May 28, 2020
Revised Aug 24, 2020
Accepted Sep 3, 2020
A micro-grid is a part of power system which able to operates in grid or
islanding mode. The most important variable that able to give us information
about the stability in islanded micro-grid network is the frequency dynamical
responses. The frequency analysis for multi-area micro-grid network model
may involve a complicated of mathematical equations. This makes
the researcher intending to omit several unnecessary parameters in order to
simplify the equations. The purpose of this paper is to show an approach to
derive the mathematical equations to represent the average behavior of
frequency dynamical responses for two different micro-grid areas. Both of
networks are assumed to have non-identical distributed generator behavior
with different parameters. The prime mover and speed governor systems are
augmented with the general swing equation. The tie line model and
the information of rotor angle was considered. Then, in the last section,
the comparison between this technique with the conventional approach using
centre of inertia (COI) technique was defined.
Keywords:
Distributed generator
Frequency responses
Islanded micro-grid
State-space representation
Two area networks
This is an open access article under the CC BY-SA license.
Corresponding Author:
Mohd Saifuzam bin Jamri,
Centre for Robotics and Industrial Automation (CeRIA),
Faculty of Electrical Engineering,
Universiti Teknikal Malaysia Melaka,
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia.
Email: saifuzam@utem.edu.my
1. INTRODUCTION
Micro-grid is a part of a power system which used an electricity sources consist dispatchable
generation and non-dispatchable renewable energy that are capable of operating in either parallel or
independent towards the main power grid [1-4]. Furthermore, micro-grid can operate in both grid connected
and islanded mode. When the micro-grid is operates in island mode, the crucial situation is an energy balance
between supply and demand because the load is dominantly supplied by the local sources. If there are any
imbalance in the network, the system can lead to significant frequency deviations [5-8]. Many research work
related to the micro-grid power system frequency study with variety of motivation has been done and most of
them involved the large system network with multiple generators and multi area. A lot of mathematical
equations has been derived to model the physical network.
The research work in [9-15] discussed about the investigation about frequency load control for
the power system network with multiple connected distributed generator. The utilized of neural predictive [16]
and linear quadratic regulator (LQR) method [17] in controling the frequency via multi-area microgrid system
basically used the large order of mathematical equations. The power sharing and frequency control strategy via
2. TELKOMNIKA Telecommun Comput El Control
Average dynamical frequency behaviour for multi-area islanded micro-grid... (Mohd Saifuzam bin Jamri)
3325
multi-area islanded power system is disccused in [18-20]. These works shows the important of frequency
deviations information in order to analyse the level of stability of the network.
The complicated mathematical models are crucial to implement and make the researcher think about
the way to simplify it by removing the unwanted parameter and put some assumption and approximation. These
situation brings the assumption of coherent generator behaviour when the multiple generators are operating in
the same area network [21]. Furthermore, same approach have been done for the multi area network with the tie
line bias control which interconnected between areas [22-24]. However, the average frequency dynamical
response of the whole system is defined through the center of inertia approach, and not in state-space
representation [25]. This paper shows an approach to derive the state-space mathematical model of multi-area
micro-grid network. The motivation of this research work is to derive and determine the evarage dynamical
behaviour of frequency network by using similarity transformation and decomposition approach. The proposed
micro-grid model was validated with the different load demand profile. At the end of the analysis, the comparison
with the conventional approach using centre of inertia (COI) has been made.
2. RESEARCH METHOD
2.1. Generator model
The main goal is to ensure that the derived mathematical equations must be able to represent
the interconnected, load sharing and frequency control. After that, one generator system was derived by using
several approximation processes to represent their average behavior. Figure 1 show the interconnected of two
areas of micro-grid.
Figure 1: The interconnected of two areas of micro-grids network
The system network is assumed to have 2 busses and 2 generators while each generator is assumed to
be equipped with the prime mover and speed governor. The model was divided into four main parts which are
rotating mass, prime mover, speed governor and load model. Each part was modeled separately and augmented
all together to become one model. The swing equation can be used to model the generator and the micro-grid
network as shown in (1). This equation describes the deviations of frequency response in per unit base.
2𝐻
𝜔 𝑠
𝑑∆𝜔
𝑑𝑡
= ∆𝑃𝑚 − ∆𝑃𝑒 (1)
Where ∆𝑃𝑚, ∆𝑃𝑒 and ∆𝜔 are the deviations of mechanical power, electrical load demand and frequency
respectively. 𝐻 is the per unit inertia constant which related to the kinetic energy at the synchronous speed with
respect to generator rating. The source of mechanical power for rotating mass is commonly known as the prime
mover. The model for prime mover is related to the changes in mechanical power output ∆𝑃𝑚 to the changes
in steam position ∆𝑃𝑔𝑉. This work, used the simplest prime mover model which can be approximated with
a single time constant 𝜏 𝑇 resulting in the following:
𝑑∆𝑃 𝑚
𝑑𝑡
=
1
𝜏 𝑇
(∆𝑃𝑔𝑣 − ∆𝑃𝑚) (2)
The speed governor system ∆𝑃𝑔𝑣 is depends on the electrical load demand. When the load demand
suddenly increased, the electrical load power exceeds the mechanical power and resulting the power deficiency.
The amount of power deficiency will influence the amount of kinetic energy stored in the rotating system.
The reduction in kinetic energy will cause the turbine speed and consequently the generator frequency to fall.
This change in speed is sensed by the turbine governor and act to adjust the turbine input valve to change
the mechanical power output to bring the speed to a new steady-state. The equation which directly describe
the speed governor behavior is as follows:
𝑑∆𝑃 𝑔𝑣
𝑑𝑡
=
1
𝜏 𝑔𝑣
(𝑘∆𝑃𝑟𝑒𝑓 −
∆𝜔
𝑅
− ∆𝑃𝑔𝑣) (3)
3. ISSN: 1693-6930
TELKOMNIKA Telecommun Comput El Control, Vol. 18, No. 6, December 2020: 3324 - 3330
3326
The speed governor mechanism act as the comparator whose take the different between the reference set power 𝑃𝑟𝑒𝑓
and the power
𝜔
𝑅
where 𝑅 is represent the slope of the curve in speed governor characteristics. 𝑘 is the integrator gain
constant to satisfy the rate of change of 𝑃𝑟𝑒𝑓 during automatic generation control operation. The load on a power
system consists of variety of electrical devices. It can be divided into two types which are loads independent of
frequency such as lighting and heating loads, and load dependent to frequency such as motor loads. The sensitivity
of such loads is depends on their speed-load characteristics and can be approximately defined by:
∆𝑃𝑒 = ∆𝑃𝐿 + 𝐷∆𝜔 (4)
∆𝑃𝐿 is the non-frequency sensitive load change and 𝐷∆𝜔 is the frequency sensitive load change. 𝐷 is expressed
as percent change in load divide by percent change in frequency.
2.2. Modeling the two micro-grid area
2.2.1. Tie-line model
In this section, each micro-grid area was assumed to have one generator model. The complete
mathematical equation for two micro-grid area take into account the information of generator rotor angle
𝑑𝛿 𝑖
𝑑𝑡
= 𝜔𝑖. Where 𝑖 is represented the number of area. This information is important to ensure the cooperative
behavior between both areas in term of amount of power sharing over the tie-line. During normal operation,
the real power transferred over the tie line is given by:
𝑃𝑖𝑗 =
|𝐸 𝑖||𝐸 𝑗|
𝑋 𝑖𝑗
𝑠𝑖𝑛𝛿𝑖𝑗 (5)
Where 𝑋𝑖𝑗 = 𝑋𝑖 + 𝑋𝑡𝑖𝑒 + 𝑋𝑗 and 𝛿𝑖𝑗 = 𝛿𝑖 − 𝛿𝑗 while 𝑖 and 𝑗 represent the area 1 and area 2 respectively.
Linearizing this equation by assuming the small deviation in the tie line power flow ∆𝑃12 from the nominal value:
∆𝑃𝑖𝑗 =
𝑑𝑃 𝑖𝑗
𝑑𝛿 𝑖𝑗
|
𝛿 𝑖𝑗0
∆𝛿𝑖𝑗 (6)
= 𝑃𝑠∆𝛿𝑖𝑗
𝑃𝑠 is the power angle at the initial operating angle 𝛿𝑖𝑗0
= 𝛿𝑖0
− 𝛿𝑗0
and it was defined as the synchronizing
power coefficient and then the tie line power deviation is take on the form:
∆𝑃𝑖𝑗 = 𝑃𝑠(∆𝛿𝑖 − ∆𝛿𝑗) (7)
The direction of power flow is dictated by the rotor angle difference. As shown in (7) show the example of
power flows from area one to area two when ∆𝑃𝑖𝑗 is positive. As shown in (4) and (7) can be combined into
(1) to become one complete equation for rotating generator as follows:
𝑑∆𝜔 𝑖
𝑑𝑡
=
1
2𝐻 𝑖
(∆𝑃 𝑚𝑖 − 𝑃𝑠(∆𝛿𝑖 − ∆𝛿𝑗) − 𝐷𝑖∆𝜔𝑖 − ∆𝑃𝐿𝑖) (8)
𝑑∆𝜔𝑗
𝑑𝑡
=
1
2𝐻𝑗
(∆𝑃 𝑚𝑗 − 𝑃𝑠(∆𝛿𝑗 − ∆𝛿𝑖) − 𝐷𝑗∆𝜔𝑗 − ∆𝑃𝐿𝑗)
2.2.2. Tie-line bias control
The rule of thumb of micro-grid system operation connected between two areas is to ensure the whole
system operating at the nominal frequency. So, this is able to consider the area control error (ACE) where each
area tends to reduce the frequency error to zero. The 𝐴𝐶𝐸𝑖 was integrated to have the rate of change with
respect to time and its information is used as ∆𝑃𝑟𝑒𝑓𝑖 for combine with speed governor model as shown in (3).
𝑑∆𝑃 𝑟𝑒𝑓𝑖
𝑑𝑡
=
𝑑∆𝐴𝐶𝐸 𝑖
𝑑𝑡
= ∆𝑃𝑖𝑗 +
∆𝜔 𝑖
𝑅 𝑖
+ 𝐷𝑖∆𝜔𝑖 (9)
= ∆𝑃𝑖𝑗 + ∆𝐵𝑖
2.2.3. State-space representation
As shown in (1-3), (8) and (9) can be written into the state-space representation. From the equation
developed, each area will provide five state variables. Since it takes into account all the information required
4. TELKOMNIKA Telecommun Comput El Control
Average dynamical frequency behaviour for multi-area islanded micro-grid... (Mohd Saifuzam bin Jamri)
3327
for two areas interconnection, the total state variables will become ten. The system can be represented in state
space as follows:
𝑥̇ = 𝐴𝑥 + 𝐵𝑢 (10)
The matrix 𝐴 and 𝐵 is arranged as shown in (11) and (12).
𝐴 =
[
−𝐷1 2𝐻1⁄ 0 − 𝑃𝑠 2𝐻1⁄ 𝑃𝑠 2𝐻1⁄ 1 2𝐻1⁄ 0 0 0 0 0
0 −𝐷2 2𝐻2⁄ 𝑃𝑠 2𝐻2⁄ − 𝑃𝑠 2𝐻2⁄ 0 1 2𝐻1⁄ 0 0 0 0
1 0 0 0 0 0 0 0 0 0
0 1 0 0 0 0 0 0 0 0
0 0 0 0 −1 𝜏 𝑇1⁄ 0 1 𝜏 𝑇1⁄ 0 0 0
0 0 0 0 0 −1 𝜏 𝑇2⁄ 0 1 𝜏 𝑇2⁄ 0 0
−1 𝜏 𝑔𝑣1 𝑅1⁄ 0 0 0 0 0 −1 𝜏 𝑔𝑣1⁄ 0 𝐾1 𝜏 𝑔𝑣1⁄ 0
0 −1 𝜏 𝑔𝑣2 𝑅2⁄ 0 0 0 0 0 −1 𝜏 𝑔𝑣2⁄ 0 𝐾2 𝜏 𝑔𝑣2⁄
−𝐵1 0 −𝑃𝑠 𝑃𝑠 0 0 0 0 0 0
0 −𝐵2 𝑃𝑠 −𝑃𝑠 0 0 0 0 0 0 ]
(11)
𝐵 = [−
1
2𝐻1
−
1
2𝐻2
0 0 0 . . . . . .0 ]
𝑇(1𝑥10)
(12)
2.2.4. An average behavior
In this section, an average behavior was determined by using similarity transformation method.
The new state variables are introduced which described the plus-minus average behavior as follows:
𝑧 𝑎 =
1
2
𝜐1 +
1
2
𝜐2 (13)
𝑧 𝑏 =
1
2
𝜐1 −
1
2
𝜐2 (14)
𝑧 is the new state variables while 𝜐 is the generator state variable. This equation would generate
the transformation matrix which would be used to generate the new vector matrix. A system in previous section
can be transformed to a similar system,
𝑧̇ = 𝑇𝐴𝑇−1
𝑧 + 𝑇𝐵𝑢 (15)
𝑇 is the transformation matrix where the columns are the coordinates of the basis vectors of the new state
vectors 𝑧 space.
3. SIMULATION SETUP
Area 1 and area 2 are assumed to have different parameters as shown in Table 1 so that their behavior
towards any load change is not identical.
Table 1. Parameter of two area micro-grid
Area 1 2
Speed regulation, R 0.05 0.0625
Frequency-sensitivity, D 0.6 0.9
Inertia constant, H 5 4
Governor time constant, 𝜏 𝑔𝑣 0.2 0.3
Turbine time constant, 𝜏 𝑇 0.5 0.6
Integrator gain, Ki = 0.3
By utilizing the matrix as shown in section 2.3 and 2.4, then substitute the parameters in Table 1, the state-space
representation is composed and transformed into plus-minus averaging model as follows:
[
𝜔 𝑎
𝛿 𝑎
𝑃𝑚𝑎
𝑃𝑔𝑣𝑎
𝑃𝑟𝑒𝑓𝑎
𝜔 𝑏
𝛿 𝑏
𝑃 𝑚𝑏
𝑃𝑔𝑣𝑏
𝑃𝑟𝑒𝑓𝑏]
=
[
−0.0862
1
0
−76.6650
−18.75
0.0263
0
0
−23.3350
−1.85
0
0
0
0
0
0
0
0
0
0
0.1125
0
−1.8350
0
0
−0.0125
0
−0.1650
0
0
0
0
1.8350
−4.1650
0
0
0
0.1650
−0.8350
0
0
0
0
1.25
0
0
0
0
0.25
0
0.0263
0
0
−23.3350
−1.85
−0.0862
1
0
−76.6650
−18.75
0.05
0
0
0
0
−0.45
0
0
0
−4
−0.0125
0
−0.1650
0
0
0.1125
0
−1.8350
0
0
0
0
0.1650
−0.8350
0
0
0
1.8350
−4.1650
0
0
0
0
0.25
0
0
0
0
1.25
0 ]
(16)
5. ISSN: 1693-6930
TELKOMNIKA Telecommun Comput El Control, Vol. 18, No. 6, December 2020: 3324 - 3330
3328
This is the state-space representation for describing the average behavior of two areas system. It can
be seen that the state vectors of the equation are divided into two partitions which related to the plus-minus
average. In order to get an average behavior of the whole network, it is possible to reduce the system order by
only taking the upper half of the state vectors and state matrix and ignore the minus average model equations
at the lower half of state vectors. The proposed model was tested under two conditions which are single sudden
load change in area 1 with 0.2 per unit deviation. The equation is reduced as follow:
𝑍 𝑎𝑣 =̇ 𝐴 𝑎𝑣 𝑍 𝑎𝑣 + 𝐵𝑎𝑣 𝑢
𝐴 𝑎𝑣 =
[
−0.0862
1
0
−76.6650
−18.75
0
0
0
0
0
0.1125
0
−1.8350
0
0
0
0
1.8350
−4.1650
0
0
0
0
1.25
0 ]
(17)
𝐵𝑎𝑣 = [−0.05 0 0 0 0] 𝑇
(18)
4. RESULTS AND ANALYSIS
4.1. Simulation results for frequency dynamical behavior
Figure 2 shows the deviations of per unit frequency dynamical response under load change in area 1
respectively. From the observations, the frequency deviation in area 1 gives more oscillations compare to area
2 since the sudden load change is highly dominant in area 1. The micro-grid system in area 2 gives a back-up
role to the micro-grid system in area 1. It clearly be seen that area 2 only contribute several amount of power
during the first moment of load change because of small frequency deviations. This phenomenon happened
due to the power flow sharing between two areas through the tie-line. Since the model considered the ACE,
the system frequency of each area will go back to the nominal after several second. The average frequency
response for the whole network can be seen in Figure 3.
Figure 2. Dynamical frequency responses for each
area networks
Figure 3. An average frequency deviation of the
whole network.
4.2. Comparison with convetional approach
The conventional approach basically only utilizes the information of inertia constant and frequency
deviations in each area to form an equation called as the center of inertia (COI) frequency.
∆𝜔 𝑐𝑜𝑖 =
∑ 𝐻 𝑖 𝜔 𝑖𝑖=1,2..
∑ 𝐻 𝑖𝑖=1,2..
(19)
Figure 4 shows the results comparison between proposed average state-space model and COI approach
as shown in (19). The result shows that the proposed average state-space model yields the similar shape like
the conventional. However, the proposed method gives a little bit lower oscillation and goes to steady-state
faster compared to COI method.
6. TELKOMNIKA Telecommun Comput El Control
Average dynamical frequency behaviour for multi-area islanded micro-grid... (Mohd Saifuzam bin Jamri)
3329
Figure 4. Comparison between proposed model and COI approach
5. CONCLUSION
The state-space mathematical model for two areas micro-grid system have been derived which
considered the tie-line model and bias control. The state-space mathematical model for average frequency
dynamical behaviour for the whole system have been derived by utilized the similarity transformation and model
decomposition technique. Compare with the aveage frequency computed using COI approach, the results shows
that the proposed technique is possible to use if the state-space representation model is needed. The proposed
average model as shown in (17) is marginally stable due to the zero eigenvalue in the state matrix which would
caused the feasiblity problem for the certain cases. However, this zero eigenvalue can be neglected since the other
state variables does not depend on it.
ACKNOWLEDGEMENTS
The authors gratefully acknowledge the Center for Robotics and Industrial Automation, Universiti
Teknikal Malaysia Melaka (CeRIA) for research facilities and support, to the Center for Research and
Innovation Management (CRIM) for funding and publication facility.
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BIOGRAPHIES OF AUTHORS
M.Saifuzam Jamri was born in October 1984. He received his bachelor degree in Electrical
Engineering (Power Electronics & Drives) from Universiti Teknikal Malaysia Melaka,
Malaysia in 2007 and received the Master Degree in Electrical Power Engineering from
Universiti Teknologi Malaysia in 2009. He is currently worked with the Universiti Teknikal
Malaysia Melaka (UTeM) as a lecturer and belongs to Centre for Robotics and Industrial
Automation (CeRIA) group. His interest is in power system study and micro-grid including
load frequency control (LFC) and renewable energy integration. He is currently persuing the
PhD in University Tekninal Malaysia Melaka under Faculty of Electrical Engineering.
Muhammad Nizam Kamarudin was born in Selangor, Malaysia. He received the B.Eng
(Hons.) Electrical from the Universiti Teknologi MARA, Malaysian in 2002, and M.Sc in
Automation and Control from the University of Newcastle Upon Tyne, United Kingdom in
2007. He received the Doctor of Philosophy in Electrical Engineering from the Universiti
Teknologi Malaysia in 2015. He is currently with the Universiti Teknikal Malaysia Melaka
(UTeM). He is the member of the Board of Engineers, Malaysia and Institute of Engineers,
Malaysia. His research interests include nonlinear controls and robust control systems. Before
joining UTeM, he worked as a Technical Engineer at the magnetron department of Samsung
Electronics Malaysia.
Mohd Luqman Mohd Jamil received B.Eng. degree from the Universiti Teknologi MARA,
Shah Alam, Malaysia, in 2000, M.Sc. degree from Univeristy of Newcastle upon Tyne, U.K.,
in 2003, and Ph.D. degree from The University of Sheffield, Sheffield, U.K., in 2011, all in
electrical engineering. He is currently an academician in Faculty of Electrical Engineering,
University Teknikal Malaysia Melaka, Melaka, Malaysia. He is also an active researcher in
Power Electronics and Drives Research Group (PEDG) that established under the same
faculty. .His research interests include the design, control and analysis of permanent-magnet
machines.