This document summarizes a research paper that proposes using an Active Power Conditioner (APC) to improve power quality in microgrids that utilize renewable energy sources like wind power. The APC acts as an interface between renewable energy sources and the microgrid's AC bus. It can inject energy into the microgrid, compensate for current harmonics, and correct the power factor. Simulation results showed the APC's innovative control strategy is effective at maintaining balanced and sinusoidal grid currents with unity power factor, even with unbalanced and nonlinear loads. This improves power quality issues in microgrids, which can be subject to disturbances from intermittent renewable energy sources.
Improved Power Quality by using STATCOM Under Various Loading ConditionsIJMTST Journal
A Power quality problem is an occurrence manifested as a nonstandard voltage, current or frequency that
results in a failure or a mis-operation of end user equipment’s. Utility distribution networks, sensitive
industrial loads and critical commercial operations suffer from various types of outages and service
interruptions which can cost significant financial losses. With the restructuring of power systems and with
shifting trend towards distributed and dispersed generation, the issue of power quality is going to take
newer dimensions. Injection of the wind power into an electric grid affects the power quality. The
performance of the wind turbine and thereby power quality are determined on the basis of measurements
and the norms followed according to the guideline specified in International Electro-technical Commission
standard, IEC-61400. 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 and these are measured according to national/international guidelines.
Static Compensator (STATCOM) is connected at a point of common coupling with a battery energy storage
system (BESS) to mitigate the power quality issues. The battery energy storage is integrated to sustain the
real power source under fluctuating wind power. Here two control schemes for STATCOM are Fuzzy logic
controller and hybrid Fuzzy logic controller. We can better response for hybrid fuzzy compare to fuzzy logic
controller. The STATCOM control scheme for the grid connected wind energy generation system for power
quality improvement is simulated using MATLAB/SIMULINK in power system block set. Finally the proposed
scheme is applied for both balanced and unbalanced linear nonlinear loads.
A CONTROL APPROACH FOR GRID INTERFACING INVERTER IN 3 PHASE 4 WIRE DISTRIBUT...IJMER
With the increase in load demand, the Renewable Energy Sources (RES) are
increasingly connected in the distribution systems which utilizes power electronic
Converters/Inverters. Nowadays, 3-phase 4-wire distribution power system has been widely used in
residential and office buildings, manufacturing facilities, schools etc This paper presents a novel
control strategy for achieving maximum benefits from the grid-interfacing inverters when installed in
3-phase 4-wire distribution systems. The inverter can thus be utilized as: 1) power converter to inject
power to the grid, and 2) shunt APF to compensate current unbalance, load current harmonics and
load neutral current. All of these functions may be accomplished either individually or
simultaneously. This new control concept is demonstrated with extensive MATLAB/Simulink
simulation studies
Power Quality Improvement of Grid Interconnection of renewable Energy Based D...IJERA Editor
This paper presents a grid interfacing inverter which compensates power quality problems and also interface Renewable Energy Sources with the help of electric grid. Renewable Energy Sources are being increasingly connected in distribution system utilizing power electronic converters. Grid interfacing inverter can be used: 1) To improve the transfer of active power harvested from RES; 2) To meet load reactive power demand support ; 3) To reduce current harmonics by incorporating the current harmonic compensator at point of common coupling(PCC) ; 4) current unbalance and neutral current compensation in case of 3-phase 4-wire system. The fuzzy logic can be used in many applications especially, when the process/models are complex to analyse by using classical methods. Mainly fuzzy logic controller is used to control DC capacitor voltage. Simulations are carried out using MATLAB/SIMULINK to verify the performance of the controller. The output shows the controller has fast dynamic response high accuracy of tracking DC voltage reference and robust to load parameters variations.
Performance Analysis of DC Micro Grid with PV-Fuel Cell Hybrid GenerationIJMREMJournal
Conventional energy resources are being replaced by Renewable energy sources mainly due to increasing
environmental concerns. Photovoltaic (PV) and Fuel cell (FC) are suitable to be used in modern DC microgrids
due to their DC output. In this research work, a DC microgrid structure is proposed for small residential areas
using hybrid PV and FC generation. Power Electronic converters are used to regulate generated voltage of the
two sources for integration to a common DC bus. Proposed system is simulated using MATLAB SIMULINK to
observe its performance. Simulation results show that output voltage is properly maintained at different DC
Comparison of upqc and dvr in wind turbine fed fsig under asymmetric faultselelijjournal
This paper presents the mitigation of faults in wind turbine connected fixed speed induction generator using unified power quality conditioner and static compensator. The UPQC consists of shunt and series converters connected back-to-back through a dc-to-dc step up converter. The presence of the dc-to-dc step converter permits the UPQC to compensate faults for long duration. The series converter is connected to the supply side whereas the shunt converter is connected to the load side. The control system of the proposed UPQC is based on Id-Iq theory. The DVR consists of shunt and series converters connected back-to-back through a dc-to-dc step up converter. The presence of the dc-to-dc step converter permits the DVR to compensate faults for long duration. The series converter is connected to the supply side whereas the shunt converter is connected to the load side. The control system of the proposed DVR is based on
hysteresis voltage controlThe proposed wind turbine fed fixed speed induction generator is evaluated and simulated using MATLAB/SIMULINK environment with UPQC and DVR under asymmetric faults
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.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Improved Power Quality by using STATCOM Under Various Loading ConditionsIJMTST Journal
A Power quality problem is an occurrence manifested as a nonstandard voltage, current or frequency that
results in a failure or a mis-operation of end user equipment’s. Utility distribution networks, sensitive
industrial loads and critical commercial operations suffer from various types of outages and service
interruptions which can cost significant financial losses. With the restructuring of power systems and with
shifting trend towards distributed and dispersed generation, the issue of power quality is going to take
newer dimensions. Injection of the wind power into an electric grid affects the power quality. The
performance of the wind turbine and thereby power quality are determined on the basis of measurements
and the norms followed according to the guideline specified in International Electro-technical Commission
standard, IEC-61400. 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 and these are measured according to national/international guidelines.
Static Compensator (STATCOM) is connected at a point of common coupling with a battery energy storage
system (BESS) to mitigate the power quality issues. The battery energy storage is integrated to sustain the
real power source under fluctuating wind power. Here two control schemes for STATCOM are Fuzzy logic
controller and hybrid Fuzzy logic controller. We can better response for hybrid fuzzy compare to fuzzy logic
controller. The STATCOM control scheme for the grid connected wind energy generation system for power
quality improvement is simulated using MATLAB/SIMULINK in power system block set. Finally the proposed
scheme is applied for both balanced and unbalanced linear nonlinear loads.
A CONTROL APPROACH FOR GRID INTERFACING INVERTER IN 3 PHASE 4 WIRE DISTRIBUT...IJMER
With the increase in load demand, the Renewable Energy Sources (RES) are
increasingly connected in the distribution systems which utilizes power electronic
Converters/Inverters. Nowadays, 3-phase 4-wire distribution power system has been widely used in
residential and office buildings, manufacturing facilities, schools etc This paper presents a novel
control strategy for achieving maximum benefits from the grid-interfacing inverters when installed in
3-phase 4-wire distribution systems. The inverter can thus be utilized as: 1) power converter to inject
power to the grid, and 2) shunt APF to compensate current unbalance, load current harmonics and
load neutral current. All of these functions may be accomplished either individually or
simultaneously. This new control concept is demonstrated with extensive MATLAB/Simulink
simulation studies
Power Quality Improvement of Grid Interconnection of renewable Energy Based D...IJERA Editor
This paper presents a grid interfacing inverter which compensates power quality problems and also interface Renewable Energy Sources with the help of electric grid. Renewable Energy Sources are being increasingly connected in distribution system utilizing power electronic converters. Grid interfacing inverter can be used: 1) To improve the transfer of active power harvested from RES; 2) To meet load reactive power demand support ; 3) To reduce current harmonics by incorporating the current harmonic compensator at point of common coupling(PCC) ; 4) current unbalance and neutral current compensation in case of 3-phase 4-wire system. The fuzzy logic can be used in many applications especially, when the process/models are complex to analyse by using classical methods. Mainly fuzzy logic controller is used to control DC capacitor voltage. Simulations are carried out using MATLAB/SIMULINK to verify the performance of the controller. The output shows the controller has fast dynamic response high accuracy of tracking DC voltage reference and robust to load parameters variations.
Performance Analysis of DC Micro Grid with PV-Fuel Cell Hybrid GenerationIJMREMJournal
Conventional energy resources are being replaced by Renewable energy sources mainly due to increasing
environmental concerns. Photovoltaic (PV) and Fuel cell (FC) are suitable to be used in modern DC microgrids
due to their DC output. In this research work, a DC microgrid structure is proposed for small residential areas
using hybrid PV and FC generation. Power Electronic converters are used to regulate generated voltage of the
two sources for integration to a common DC bus. Proposed system is simulated using MATLAB SIMULINK to
observe its performance. Simulation results show that output voltage is properly maintained at different DC
Comparison of upqc and dvr in wind turbine fed fsig under asymmetric faultselelijjournal
This paper presents the mitigation of faults in wind turbine connected fixed speed induction generator using unified power quality conditioner and static compensator. The UPQC consists of shunt and series converters connected back-to-back through a dc-to-dc step up converter. The presence of the dc-to-dc step converter permits the UPQC to compensate faults for long duration. The series converter is connected to the supply side whereas the shunt converter is connected to the load side. The control system of the proposed UPQC is based on Id-Iq theory. The DVR consists of shunt and series converters connected back-to-back through a dc-to-dc step up converter. The presence of the dc-to-dc step converter permits the DVR to compensate faults for long duration. The series converter is connected to the supply side whereas the shunt converter is connected to the load side. The control system of the proposed DVR is based on
hysteresis voltage controlThe proposed wind turbine fed fixed speed induction generator is evaluated and simulated using MATLAB/SIMULINK environment with UPQC and DVR under asymmetric faults
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.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Improvement of Power Quality using Fuzzy Logic Controller in Grid Connected P...IAES-IJPEDS
In this paper, the design of combined operation of UPQC and PV-ARRAY is designed. The proposed system is composed of series and shunt inverters connected back to back by a dc-link to which pv-array is connected. This system is able to compensate voltage and current related problems both in inter-connected mode and islanding mode by injecting active power to grid. The fundamental aspect is that the power electronic devices (PE) and sensitive equipments (SE) are normally designed to work in non-polluted power system, so they would suffer from malfunctions when supply voltage is not pure sinusoidal. Thus this proposed operating strategy with flexible operation mode improves the power quality of the grid system combining photovoltaic array with a control of unified power quality conditioner. Pulse Width Modulation (PWM) is used in both three phase four leg inverters. A Proportional Integral (PI) and Fuzzy Logic Controllers are used for power quality improvement by reducing the distortions in the output power. The simulated results were compared among the two controller’s strategies With pi controller and fuzzy logic controller
This paper presents a droop control technique for equal power sharing in islanded microgrid. In this study, the proposed controller is based on the frequency droop method, is applied to a robust droop controller in parallel connected inverters. The previous robust droop controller deals with voltage droop method. A modification has been formed against this controller by adding a fuzzy logic controller with the frequency droop method. The only sharing error which is concentrated in this paper is the error in sharing the rated frequency among the inverters. By adapting fuzzy in the robust droop, it tries to eliminate the frequency error, hence that the frequency reference of the inverters keeps maintain at 50Hz. A derivation of generalized models of a single-phase parallel-connected inverter system is shown. The simulation results show that the proposed controller with FLC is able to improve the stability of frequency reference and the performance of power sharing between the inverters under the inductive line impedance.
LOAD FREQUENCY CONTROL IN TWO AREA NETWORK INCLUDING DGIAEME Publication
Automatic Generation Control (AGC) is associate integral a part of Energy Management
System. This paper deals with the automatic generation control of interconnected multi area grid
network. The first purpose of the AGC is to balance the full system generation against system load
and losses so the specified frequency and power interchange with neighboring systems are
maintained. Any pair between generation and demand causes the system frequency to deviate from
regular worth. So high frequency deviation could result in system collapse. This necessitates
associate correct and quick acting controller to take care of constant nominal frequency. The
limitations of the conventional controls are slow and lack of efficiency in handling system nonlinearity.
This leads to develop a control technique for AGC. In this paper both conventional and
PI viz. Proportional Integral controller approach of automatic generation control has been
examined. PI based AGC has been used for all optimization purposes. System performance has
been evaluated at various disturbances such as, load disturbances, grid disturbances and both load
and grid disturbances. Various responses due to conventional and proposed PI based AGC
controllers have been compared at load disturbances, grid disturbances and both load and grid
disturbances.
Enhancement in Power Quality With Grid Interconnection of Renewable Energy So...IJERA Editor
At present the 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 power converter to inject power generated from RES to the grid and 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.
In this paper, using a neural controller and a genetic optimization algorithm to control the voltage as well as, control the frequency of the grid along with the management of the reactive power of the micro-grid to control the output power during islanding using Simultaneous bilateral power converters with voltage/frequency droop strategy and optimization of PI coefficients of parallel power converters by genetic-neural micro-grid algorithm to suppress AC side-current flow that increases stability and improvement of conditions frequency and voltage are discussed. Given the performance of the micro-grid in two simulation scenarios, namely transition from on-grid to off-grid, the occurrence of a step change in load in island mode as well as return to working mode is connected. The ability to detect the robust performance and proper performance of two-level neural controller. The controller performance time was also very good, indicating the appropriate features of the method used to design the controller, namely two-level neural, genetics. The main advantage of this method is its simplicity of design. The method used is also efficient and resistant to changes in the system, which results from the simulations.
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.
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 project 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 can thus be utilized as:
1) power converter to inject power generated from RES to the grid &
2) shunt APF to compensate current unbalance, load current harmonics, load reactive power demand and load neutral current.
A Power quality problem is an occurrence of nonstandard voltage, current or frequency that results in a
failure or a misoperation of end user equipments. Utility distribution networks, sensitive industrial loads and
critical commercial operations suffer from various types of outages and service interruptions which can cost
significant financial losses. With the increase in load demand, the Renewable Energy Sources (RES) are
increasingly connected in the distribution systems which utilizes power electronic Converters/Inverters. This
paper presents a single-stage, three-phase grid connected solar photovoltaic (SPV) system. The proposed system
is dual purpose, as it not only feeds extracted solar energy into the grid but it also helps in improving power
quality in the distribution system. The presented system serves the purpose of maximum power point tracking
(MPPT), feeding SPV energy to the grid, harmonics mitigation of loads connected at point of common coupling
(PCC) and balancing the grid currents. The SPV system uses a three-phase voltage source converter (VSC) for
performing all these functions. An improved linear sinusoidal tracer (ILST)-based control algorithm is proposed
for control of VSC. In the proposed system, a variable dc link voltage is used for MPPT. An instantaneous
compensation technique is used incorporating changes in PV power for fast dynamic response. The SPV system
is first simulated in MATLAB along with Simulink and simpower system toolboxes.
Overview: Simulation Analysis of low voltage DC micro grid - An investigation...IJSRD
The micro grid concept has the potential to solve major problems arising from large penetration of distributed generation in distribution systems. The micro grid was designed to operate connected to the main network. The micro grid operated appropriately for different steady state operating conditions. A proper control strategy should be implemented for a successful operation of a micro grid. This paper presents a performance study of a dc micro-grid when it is used a voltage droop technique to regulated the grid voltage and to control the load sharing between different sources like Photovoltaic cell , Fuel Cell, Batteries, etc. Some aspects about centralized (master-slave) and decentralized (voltage droop) control strategies are presented. In this paper, the work done in the field of Micro Grid has been reviewed.
This paper deals with controlling a grid-connected dual-active bridge multilevel inverter for renewable energy integration. The concept of direct power control is integrated with model predictive control algorithm, which is termed as predictive direct power control, to control the real and reactive power injected into the power grid. The proposed multilevel inverter allows more options of feasible voltage vectors for switching vector selections in order to generate multilevel outputs, and thereby obtaining high power quality in the power grid. By using the predictive direct power control, simulation results show that the proposed multilevel inverter produces lower power ripple and manage to achieve currents with low total harmonic distortion which are well within the IEEE standard. The modeling and simulation of the system are implemented and validated by MATLAB Simulink software.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Mitigation of Voltage Fluctuations in Power System Using STATCOMIJERA Editor
Wind energy being a renewable source of energy is enjoying a rapid growth globally. However, wind energy being an uncontrollable source of energy coupled with the fact that it uses distributed induction generators for power conversion poses a challenge in integrating a large scale wind-farm into a weak power system. An actual weak power system with two large Wind-Farms (WFs) coupled to it is introduced as part of this study. A model of this integrated system along with a STATCOM for steady state and dynamic impact study is developed in the MATLAB/Simulink environment. The power quality issues are highlighted and a centralized STATCOM is proposed to solve the issue of the voltage fluctuations in particular in addition to addressing the other issues. Based on the results obtained from the simulation, the system voltage control issues are analyzed and the location of STATCOM is assessed. Finally, a STATCOM control strategy for suppression of voltage fluctuations is presented.
Analysis and Simulation of Solar PV Connected with Grid Accomplished with Boo...YogeshIJTSRD
This paper deals with a solar PV array connected with grid system. This system consists of PV cells with 30 KW system, Boost converter, three phase inverter with suitable control system and three phase load. This paper gives analysis of each components of the system. The output voltage from the solar PV cells are variable according to radiation intensity and temperature so in order to connect with grid the output voltage should be fixed and converted to AC voltage and this job will be done by an inverter. A very effective control system has been developed for the inverter based on pulse width modulation. This paper presents an intensive performance and dynamic behavior of a grid related PV energy conversion system. The PV system is developed and simulated with the help of MATLAB Simulink software environment. Abhishek Verma | Dr. Anup Mishra | Brahma Nand Thakur "Analysis and Simulation of Solar PV Connected with Grid Accomplished with Boost Converter and PWM Based Inverter" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-3 , April 2021, URL: https://www.ijtsrd.com/papers/ijtsrd40056.pdf Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/40056/analysis-and-simulation-of-solar-pv-connected-with-grid-accomplished-with-boost-converter-and-pwm-based-inverter/abhishek-verma
Control of Two Stage PV Power System under the Unbalanced Three Phase Grid Vo...ijtsrd
This paper proposes a dynamic power decoupling DPD strategy for the three phase grid tied PV power system without increasing the dc link capacitance. Under normal condition, the interleaved boost converter will extract the maximum power point MPP from the PV array and the three phase inverter will inject the power to the grid. During the unbalanced grid fault scenario, the input power and current of the interleaved boost converter will be controlled by the proposed DPD to achieve the power decoupling capability as well as to eliminate the dc link voltage oscillation. The proposed work has been carried out in MATLAB, and the results are presented. Manasa | Nirmaladevi ""Control of Two Stage PV Power System under the Unbalanced Three-Phase Grid Voltages"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-2 , February 2020,
URL: https://www.ijtsrd.com/papers/ijtsrd30091.pdf
Paper Url : https://www.ijtsrd.com/engineering/electrical-engineering/30091/control-of-two-stage-pv-power-system-under-the-unbalanced-three-phase-grid-voltages/manasa
Comparative of Conventional and Intelligence Controller based Hybrid Generati...IJERD Editor
Harmonic pollution of the power supply system has risen significantly in recent years due primarily
to an increase of non-linear loads connected to the utility through residential, commercial and industrial
customers. This paper, proposed a solution to eliminate the harmonics introduced by the nonlinear loads in
steady and in transients. It presents a predictive current control strategy for achieving maximum benefits from
these grid-interfacing inverters implementing conventional DC link controller and intelligence controller, when
installed in 3-phase 4-leg voltage source inverter (VSI). The inverter is controlled to perform as a multi-function
device by incorporating active power filter functionality. The use of a four-leg voltage-source inverter allows
the compensation of current harmonic components, as well as unbalanced current generated by three-phase
nonlinear loads. Renewable energy resources (RES) are being increasingly connected in distribution systems
utilizing power electronic converters. The compensation performance of the proposed active power filter and the
associated hybrid PV/Wind system generation scheme with new control scheme is demonstrated to improve the
power quality features is simulated using MATLAB/SIMULINK.
Improvement of Power Quality using Fuzzy Logic Controller in Grid Connected P...IAES-IJPEDS
In this paper, the design of combined operation of UPQC and PV-ARRAY is designed. The proposed system is composed of series and shunt inverters connected back to back by a dc-link to which pv-array is connected. This system is able to compensate voltage and current related problems both in inter-connected mode and islanding mode by injecting active power to grid. The fundamental aspect is that the power electronic devices (PE) and sensitive equipments (SE) are normally designed to work in non-polluted power system, so they would suffer from malfunctions when supply voltage is not pure sinusoidal. Thus this proposed operating strategy with flexible operation mode improves the power quality of the grid system combining photovoltaic array with a control of unified power quality conditioner. Pulse Width Modulation (PWM) is used in both three phase four leg inverters. A Proportional Integral (PI) and Fuzzy Logic Controllers are used for power quality improvement by reducing the distortions in the output power. The simulated results were compared among the two controller’s strategies With pi controller and fuzzy logic controller
This paper presents a droop control technique for equal power sharing in islanded microgrid. In this study, the proposed controller is based on the frequency droop method, is applied to a robust droop controller in parallel connected inverters. The previous robust droop controller deals with voltage droop method. A modification has been formed against this controller by adding a fuzzy logic controller with the frequency droop method. The only sharing error which is concentrated in this paper is the error in sharing the rated frequency among the inverters. By adapting fuzzy in the robust droop, it tries to eliminate the frequency error, hence that the frequency reference of the inverters keeps maintain at 50Hz. A derivation of generalized models of a single-phase parallel-connected inverter system is shown. The simulation results show that the proposed controller with FLC is able to improve the stability of frequency reference and the performance of power sharing between the inverters under the inductive line impedance.
LOAD FREQUENCY CONTROL IN TWO AREA NETWORK INCLUDING DGIAEME Publication
Automatic Generation Control (AGC) is associate integral a part of Energy Management
System. This paper deals with the automatic generation control of interconnected multi area grid
network. The first purpose of the AGC is to balance the full system generation against system load
and losses so the specified frequency and power interchange with neighboring systems are
maintained. Any pair between generation and demand causes the system frequency to deviate from
regular worth. So high frequency deviation could result in system collapse. This necessitates
associate correct and quick acting controller to take care of constant nominal frequency. The
limitations of the conventional controls are slow and lack of efficiency in handling system nonlinearity.
This leads to develop a control technique for AGC. In this paper both conventional and
PI viz. Proportional Integral controller approach of automatic generation control has been
examined. PI based AGC has been used for all optimization purposes. System performance has
been evaluated at various disturbances such as, load disturbances, grid disturbances and both load
and grid disturbances. Various responses due to conventional and proposed PI based AGC
controllers have been compared at load disturbances, grid disturbances and both load and grid
disturbances.
Enhancement in Power Quality With Grid Interconnection of Renewable Energy So...IJERA Editor
At present the 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 power converter to inject power generated from RES to the grid and 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.
In this paper, using a neural controller and a genetic optimization algorithm to control the voltage as well as, control the frequency of the grid along with the management of the reactive power of the micro-grid to control the output power during islanding using Simultaneous bilateral power converters with voltage/frequency droop strategy and optimization of PI coefficients of parallel power converters by genetic-neural micro-grid algorithm to suppress AC side-current flow that increases stability and improvement of conditions frequency and voltage are discussed. Given the performance of the micro-grid in two simulation scenarios, namely transition from on-grid to off-grid, the occurrence of a step change in load in island mode as well as return to working mode is connected. The ability to detect the robust performance and proper performance of two-level neural controller. The controller performance time was also very good, indicating the appropriate features of the method used to design the controller, namely two-level neural, genetics. The main advantage of this method is its simplicity of design. The method used is also efficient and resistant to changes in the system, which results from the simulations.
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.
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 project 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 can thus be utilized as:
1) power converter to inject power generated from RES to the grid &
2) shunt APF to compensate current unbalance, load current harmonics, load reactive power demand and load neutral current.
A Power quality problem is an occurrence of nonstandard voltage, current or frequency that results in a
failure or a misoperation of end user equipments. Utility distribution networks, sensitive industrial loads and
critical commercial operations suffer from various types of outages and service interruptions which can cost
significant financial losses. With the increase in load demand, the Renewable Energy Sources (RES) are
increasingly connected in the distribution systems which utilizes power electronic Converters/Inverters. This
paper presents a single-stage, three-phase grid connected solar photovoltaic (SPV) system. The proposed system
is dual purpose, as it not only feeds extracted solar energy into the grid but it also helps in improving power
quality in the distribution system. The presented system serves the purpose of maximum power point tracking
(MPPT), feeding SPV energy to the grid, harmonics mitigation of loads connected at point of common coupling
(PCC) and balancing the grid currents. The SPV system uses a three-phase voltage source converter (VSC) for
performing all these functions. An improved linear sinusoidal tracer (ILST)-based control algorithm is proposed
for control of VSC. In the proposed system, a variable dc link voltage is used for MPPT. An instantaneous
compensation technique is used incorporating changes in PV power for fast dynamic response. The SPV system
is first simulated in MATLAB along with Simulink and simpower system toolboxes.
Overview: Simulation Analysis of low voltage DC micro grid - An investigation...IJSRD
The micro grid concept has the potential to solve major problems arising from large penetration of distributed generation in distribution systems. The micro grid was designed to operate connected to the main network. The micro grid operated appropriately for different steady state operating conditions. A proper control strategy should be implemented for a successful operation of a micro grid. This paper presents a performance study of a dc micro-grid when it is used a voltage droop technique to regulated the grid voltage and to control the load sharing between different sources like Photovoltaic cell , Fuel Cell, Batteries, etc. Some aspects about centralized (master-slave) and decentralized (voltage droop) control strategies are presented. In this paper, the work done in the field of Micro Grid has been reviewed.
This paper deals with controlling a grid-connected dual-active bridge multilevel inverter for renewable energy integration. The concept of direct power control is integrated with model predictive control algorithm, which is termed as predictive direct power control, to control the real and reactive power injected into the power grid. The proposed multilevel inverter allows more options of feasible voltage vectors for switching vector selections in order to generate multilevel outputs, and thereby obtaining high power quality in the power grid. By using the predictive direct power control, simulation results show that the proposed multilevel inverter produces lower power ripple and manage to achieve currents with low total harmonic distortion which are well within the IEEE standard. The modeling and simulation of the system are implemented and validated by MATLAB Simulink software.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Mitigation of Voltage Fluctuations in Power System Using STATCOMIJERA Editor
Wind energy being a renewable source of energy is enjoying a rapid growth globally. However, wind energy being an uncontrollable source of energy coupled with the fact that it uses distributed induction generators for power conversion poses a challenge in integrating a large scale wind-farm into a weak power system. An actual weak power system with two large Wind-Farms (WFs) coupled to it is introduced as part of this study. A model of this integrated system along with a STATCOM for steady state and dynamic impact study is developed in the MATLAB/Simulink environment. The power quality issues are highlighted and a centralized STATCOM is proposed to solve the issue of the voltage fluctuations in particular in addition to addressing the other issues. Based on the results obtained from the simulation, the system voltage control issues are analyzed and the location of STATCOM is assessed. Finally, a STATCOM control strategy for suppression of voltage fluctuations is presented.
Analysis and Simulation of Solar PV Connected with Grid Accomplished with Boo...YogeshIJTSRD
This paper deals with a solar PV array connected with grid system. This system consists of PV cells with 30 KW system, Boost converter, three phase inverter with suitable control system and three phase load. This paper gives analysis of each components of the system. The output voltage from the solar PV cells are variable according to radiation intensity and temperature so in order to connect with grid the output voltage should be fixed and converted to AC voltage and this job will be done by an inverter. A very effective control system has been developed for the inverter based on pulse width modulation. This paper presents an intensive performance and dynamic behavior of a grid related PV energy conversion system. The PV system is developed and simulated with the help of MATLAB Simulink software environment. Abhishek Verma | Dr. Anup Mishra | Brahma Nand Thakur "Analysis and Simulation of Solar PV Connected with Grid Accomplished with Boost Converter and PWM Based Inverter" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-3 , April 2021, URL: https://www.ijtsrd.com/papers/ijtsrd40056.pdf Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/40056/analysis-and-simulation-of-solar-pv-connected-with-grid-accomplished-with-boost-converter-and-pwm-based-inverter/abhishek-verma
Control of Two Stage PV Power System under the Unbalanced Three Phase Grid Vo...ijtsrd
This paper proposes a dynamic power decoupling DPD strategy for the three phase grid tied PV power system without increasing the dc link capacitance. Under normal condition, the interleaved boost converter will extract the maximum power point MPP from the PV array and the three phase inverter will inject the power to the grid. During the unbalanced grid fault scenario, the input power and current of the interleaved boost converter will be controlled by the proposed DPD to achieve the power decoupling capability as well as to eliminate the dc link voltage oscillation. The proposed work has been carried out in MATLAB, and the results are presented. Manasa | Nirmaladevi ""Control of Two Stage PV Power System under the Unbalanced Three-Phase Grid Voltages"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-2 , February 2020,
URL: https://www.ijtsrd.com/papers/ijtsrd30091.pdf
Paper Url : https://www.ijtsrd.com/engineering/electrical-engineering/30091/control-of-two-stage-pv-power-system-under-the-unbalanced-three-phase-grid-voltages/manasa
Comparative of Conventional and Intelligence Controller based Hybrid Generati...IJERD Editor
Harmonic pollution of the power supply system has risen significantly in recent years due primarily
to an increase of non-linear loads connected to the utility through residential, commercial and industrial
customers. This paper, proposed a solution to eliminate the harmonics introduced by the nonlinear loads in
steady and in transients. It presents a predictive current control strategy for achieving maximum benefits from
these grid-interfacing inverters implementing conventional DC link controller and intelligence controller, when
installed in 3-phase 4-leg voltage source inverter (VSI). The inverter is controlled to perform as a multi-function
device by incorporating active power filter functionality. The use of a four-leg voltage-source inverter allows
the compensation of current harmonic components, as well as unbalanced current generated by three-phase
nonlinear loads. Renewable energy resources (RES) are being increasingly connected in distribution systems
utilizing power electronic converters. The compensation performance of the proposed active power filter and the
associated hybrid PV/Wind system generation scheme with new control scheme is demonstrated to improve the
power quality features is simulated using MATLAB/SIMULINK.
Power Quality Improvement with Multilevel Inverter Based IPQC for MicrogridIJMTST Journal
A micro grid is a hybrid power system consists of several distributed resources and local loads .Now a
days with increasing on a day to day life micro grid plays a vital role in power generation using Renewable
Energy Sources. Usage of power electronic devices in a micro grid results in harmonic generation and leads to
various power quality issues. Inorder to overcome voltage fluctuations and over current a magnetic flux
control based variable reactor is proposed. The performance of IPQC can be verified by using
MATLAB/SIMULINK`
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.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
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
OPTIMAL CURRENT REGULATION STRATEGY FOR THREE-PHASE BACK-TOBACK ACTIVE POWER ...Ijorat1
Abstract: The objective of this paper is to propose a three phase back-to-back power conditioner with optimal a current
regulation strategy in microgrid. To achieve high stability ,the frequency and the voltage of the microgrid is controlled
by using bidirectional power flow control .The active and reactive power of Active Power Conditioner(APC) is used
here. The dc-link capacitor is the main component of the back-to-back power conditioner for power decoupling and
power flow balancing. Optimal current regulation strategy is developed to improve the power quality and stability of
the micro grids as well as to reduce the dc link capacitance. Under steady state, the optimal ac current regulation is
able to achieve the dc-link voltage regulation and to reduce the injected ac line current variation. Simulation result was
used to demonstrate the feasibility and performance of the proposed active power conditioner.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
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.
A Novel Technique for Enhancing Active and Reactive Power Quality for Renewab...IJMER
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 results.
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.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Operation and Control of Grid Connected Hybrid AC/DC Microgrid using Various RESIAES-IJPEDS
This paper proposes a Hybrid AC/DC Microgrid in alliance with Photo Voltaic (PV) energy, Wind Energy and Proton Exchange Membrane (PEM) Fuel cells. Microgrids are becoming increasingly attractive to the researchers because of the less greenhouse gases, low running cost, and flexibility to operate in connection with utility grid. The Hybrid AC/DC Microgrid constitutes independent AC and DC subgrids, where all the corresponding sources and loads are connected to their respective buses and these buses are interfaced using an interfacing converter. The Hybrid AC/DC Microgrid increases system efficiency by reducing the multiple reverse conversions involved in conventional RES integration to grid. A Small Hybrid AC/DC Microgrid in grid connected mode was modeled and simulated in MATLAB- SIMULINK environment. The simulation results prove the stable operation considering the uncertainty of generations and loads.
Research Inventy : International Journal of Engineering and Scienceresearchinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Implementation of a grid-tied emergency back-up power supply for medium and l...IJECEIAES
Emergency back-up power supply units are necessary in case of grid power shortage, considerably poor regulation and costly establishment of a power system facility. In this regard, power electronic converters based systems emerge as consistent, properly controlled and inexpensive electrical energy providers. This paper presents an implemented design of a grid-tied emergency back-up power supply for medium and low power applications. There are a rectifier-link boost derived DC-DC battery charging circuit and a 4-switch push-pull power inverter (DC-AC) circuit, which are controlled by pulse width modulation (PWM) signals. A changeover relay based transfer switch controls the power flow towards the utility loads. During off-grid situations, loads are fed power by the proposed system and during on-grid situations, battery is charged by an AC-link rectifier-fed boost converter. Charging phenomenon of the battery is controlled by a relay switched protection circuit. Laboratory experiments are carried out extensively for different loads. Power quality assessments along with back-up durations are recorded and analyzed. In addition, a cost allocation affirms the economic feasibility of the proposed framework in case of reasonable consumer applications. The test-bed results corroborate the reliability of the research work.
Simulation of a 13-Level Inverter with Facts Capability for Distributed Energ...IJMTST Journal
This Paper Presents A whole New resonant twin active bridge(DAB) topology, that uses a tuned inductor-capacitor-inductor(LCL) network. As compared to ancient DAB topologies, the planned topologies significantly reduced the bridge current, lowering every physical phenomenon and alter losses and conjointly VA rating associated with the bridges. The performance of the DAB is investigated using a mathematical model at a lower place varied operational conditions. Experiment results of a model is reduced the outflow current of the circuit. are presented with discussion to demonstrate the improved performance of the LCL DAB topology. Result clearly that the planned DAB Topology provide higher efficiency over an oversized vary of every input voltage and as compared to ancient DAB topology
Similar to International Journal of Engineering Research and Development (IJERD) (20)
A Novel Method for Prevention of Bandwidth Distributed Denial of Service AttacksIJERD Editor
Distributed Denial of Service (DDoS) Attacks became a massive threat to the Internet. Traditional
Architecture of internet is vulnerable to the attacks like DDoS. Attacker primarily acquire his army of Zombies,
then that army will be instructed by the Attacker that when to start an attack and on whom the attack should be
done. In this paper, different techniques which are used to perform DDoS Attacks, Tools that were used to
perform Attacks and Countermeasures in order to detect the attackers and eliminate the Bandwidth Distributed
Denial of Service attacks (B-DDoS) are reviewed. DDoS Attacks were done by using various Flooding
techniques which are used in DDoS attack.
The main purpose of this paper is to design an architecture which can reduce the Bandwidth
Distributed Denial of service Attack and make the victim site or server available for the normal users by
eliminating the zombie machines. Our Primary focus of this paper is to dispute how normal machines are
turning into zombies (Bots), how attack is been initiated, DDoS attack procedure and how an organization can
save their server from being a DDoS victim. In order to present this we implemented a simulated environment
with Cisco switches, Routers, Firewall, some virtual machines and some Attack tools to display a real DDoS
attack. By using Time scheduling, Resource Limiting, System log, Access Control List and some Modular
policy Framework we stopped the attack and identified the Attacker (Bot) machines
Hearing loss is one of the most common human impairments. It is estimated that by year 2015 more
than 700 million people will suffer mild deafness. Most can be helped by hearing aid devices depending on the
severity of their hearing loss. This paper describes the implementation and characterization details of a dual
channel transmitter front end (TFE) for digital hearing aid (DHA) applications that use novel micro
electromechanical- systems (MEMS) audio transducers and ultra-low power-scalable analog-to-digital
converters (ADCs), which enable a very-low form factor, energy-efficient implementation for next-generation
DHA. The contribution of the design is the implementation of the dual channel MEMS microphones and powerscalable
ADC system.
Influence of tensile behaviour of slab on the structural Behaviour of shear c...IJERD Editor
-A composite beam is composed of a steel beam and a slab connected by means of shear connectors
like studs installed on the top flange of the steel beam to form a structure behaving monolithically. This study
analyzes the effects of the tensile behavior of the slab on the structural behavior of the shear connection like slip
stiffness and maximum shear force in composite beams subjected to hogging moment. The results show that the
shear studs located in the crack-concentration zones due to large hogging moments sustain significantly smaller
shear force and slip stiffness than the other zones. Moreover, the reduction of the slip stiffness in the shear
connection appears also to be closely related to the change in the tensile strain of rebar according to the increase
of the load. Further experimental and analytical studies shall be conducted considering variables such as the
reinforcement ratio and the arrangement of shear connectors to achieve efficient design of the shear connection
in composite beams subjected to hogging moment.
Gold prospecting using Remote Sensing ‘A case study of Sudan’IJERD Editor
Gold has been extracted from northeast Africa for more than 5000 years, and this may be the first
place where the metal was extracted. The Arabian-Nubian Shield (ANS) is an exposure of Precambrian
crystalline rocks on the flanks of the Red Sea. The crystalline rocks are mostly Neoproterozoic in age. ANS
includes the nations of Israel, Jordan. Egypt, Saudi Arabia, Sudan, Eritrea, Ethiopia, Yemen, and Somalia.
Arabian Nubian Shield Consists of juvenile continental crest that formed between 900 550 Ma, when intra
oceanic arc welded together along ophiolite decorated arc. Primary Au mineralization probably developed in
association with the growth of intra oceanic arc and evolution of back arc. Multiple episodes of deformation
have obscured the primary metallogenic setting, but at least some of the deposits preserve evidence that they
originate as sea floor massive sulphide deposits.
The Red Sea Hills Region is a vast span of rugged, harsh and inhospitable sector of the Earth with
inimical moon-like terrain, nevertheless since ancient times it is famed to be an abode of gold and was a major
source of wealth for the Pharaohs of ancient Egypt. The Pharaohs old workings have been periodically
rediscovered through time. Recent endeavours by the Geological Research Authority of Sudan led to the
discovery of a score of occurrences with gold and massive sulphide mineralizations. In the nineties of the
previous century the Geological Research Authority of Sudan (GRAS) in cooperation with BRGM utilized
satellite data of Landsat TM using spectral ratio technique to map possible mineralized zones in the Red Sea
Hills of Sudan. The outcome of the study mapped a gossan type gold mineralization. Band ratio technique was
applied to Arbaat area and a signature of alteration zone was detected. The alteration zones are commonly
associated with mineralization. The alteration zones are commonly associated with mineralization. A filed check
confirmed the existence of stock work of gold bearing quartz in the alteration zone. Another type of gold
mineralization that was discovered using remote sensing is the gold associated with metachert in the Atmur
Desert.
Reducing Corrosion Rate by Welding DesignIJERD Editor
The paper addresses the importance of welding design to prevent corrosion at steel. Welding is
used to join pipe, profiles at bridges, spindle, and a lot more part of engineering construction. The
problems happened associated with welding are common issues in these fields, especially corrosion.
Corrosion can be reduced with many methods, they are painting, controlling humidity, and also good
welding design. In the research, it can be found that reducing residual stress on the welding can be
solved in corrosion rate reduction problem.
Preheating on 500oC and 600oC give better condition to reduce corosion rate than condition after
preheating 400oC. For all welding groove type, material with 500oC and 600oC preheating after 14 days
corrosion test is 0,5%-0,69% lost. Material with 400oC preheating after 14 days corrosion test is 0,57%-0,76%
lost.
Welding groove also influence corrosion rate. X and V type welding groove give better condition to reduce
corrosion rate than use 1/2V and 1/2 X welding groove. After 14 days corrosion test, the samples with
X welding groove type is 0,5%-0,57% lost. The samples with V welding groove after 14 days corrosion test is
0,51%-0,59% lost. The samples with 1/2V and 1/2X welding groove after 14 days corrosion test is 0,58%-
0,71% lost.
Router 1X3 – RTL Design and VerificationIJERD Editor
Routing is the process of moving a packet of data from source to destination and enables messages
to pass from one computer to another and eventually reach the target machine. A router is a networking device
that forwards data packets between computer networks. It is connected to two or more data lines from different
networks (as opposed to a network switch, which connects data lines from one single network). This paper,
mainly emphasizes upon the study of router device, it‟s top level architecture, and how various sub-modules of
router i.e. Register, FIFO, FSM and Synchronizer are synthesized, and simulated and finally connected to its top
module.
Active Power Exchange in Distributed Power-Flow Controller (DPFC) At Third Ha...IJERD Editor
This paper presents a component within the flexible ac-transmission system (FACTS) family, called
distributed power-flow controller (DPFC). The DPFC is derived from the unified power-flow controller (UPFC)
with an eliminated common dc link. The DPFC has the same control capabilities as the UPFC, which comprise
the adjustment of the line impedance, the transmission angle, and the bus voltage. The active power exchange
between the shunt and series converters, which is through the common dc link in the UPFC, is now through the
transmission lines at the third-harmonic frequency. DPFC multiple small-size single-phase converters which
reduces the cost of equipment, no voltage isolation between phases, increases redundancy and there by
reliability increases. The principle and analysis of the DPFC are presented in this paper and the corresponding
simulation results that are carried out on a scaled prototype are also shown.
Mitigation of Voltage Sag/Swell with Fuzzy Control Reduced Rating DVRIJERD Editor
Power quality has been an issue that is becoming increasingly pivotal in industrial electricity
consumers point of view in recent times. Modern industries employ Sensitive power electronic equipments,
control devices and non-linear loads as part of automated processes to increase energy efficiency and
productivity. Voltage disturbances are the most common power quality problem due to this the use of a large
numbers of sophisticated and sensitive electronic equipment in industrial systems is increased. This paper
discusses the design and simulation of dynamic voltage restorer for improvement of power quality and
reduce the harmonics distortion of sensitive loads. Power quality problem is occurring at non-standard
voltage, current and frequency. Electronic devices are very sensitive loads. In power system voltage sag,
swell, flicker and harmonics are some of the problem to the sensitive load. The compensation capability
of a DVR depends primarily on the maximum voltage injection ability and the amount of stored
energy available within the restorer. This device is connected in series with the distribution feeder at
medium voltage. A fuzzy logic control is used to produce the gate pulses for control circuit of DVR and the
circuit is simulated by using MATLAB/SIMULINK software.
Study on the Fused Deposition Modelling In Additive ManufacturingIJERD Editor
Additive manufacturing process, also popularly known as 3-D printing, is a process where a product
is created in a succession of layers. It is based on a novel materials incremental manufacturing philosophy.
Unlike conventional manufacturing processes where material is removed from a given work price to derive the
final shape of a product, 3-D printing develops the product from scratch thus obviating the necessity to cut away
materials. This prevents wastage of raw materials. Commonly used raw materials for the process are ABS
plastic, PLA and nylon. Recently the use of gold, bronze and wood has also been implemented. The complexity
factor of this process is 0% as in any object of any shape and size can be manufactured.
Spyware triggering system by particular string valueIJERD Editor
This computer programme can be used for good and bad purpose in hacking or in any general
purpose. We can say it is next step for hacking techniques such as keylogger and spyware. Once in this system if
user or hacker store particular string as a input after that software continually compare typing activity of user
with that stored string and if it is match then launch spyware programme.
A Blind Steganalysis on JPEG Gray Level Image Based on Statistical Features a...IJERD Editor
This paper presents a blind steganalysis technique to effectively attack the JPEG steganographic
schemes i.e. Jsteg, F5, Outguess and DWT Based. The proposed method exploits the correlations between
block-DCTcoefficients from intra-block and inter-block relation and the statistical moments of characteristic
functions of the test image is selected as features. The features are extracted from the BDCT JPEG 2-array.
Support Vector Machine with cross-validation is implemented for the classification.The proposed scheme gives
improved outcome in attacking.
Secure Image Transmission for Cloud Storage System Using Hybrid SchemeIJERD Editor
- Data over the cloud is transferred or transmitted between servers and users. Privacy of that
data is very important as it belongs to personal information. If data get hacked by the hacker, can be
used to defame a person’s social data. Sometimes delay are held during data transmission. i.e. Mobile
communication, bandwidth is low. Hence compression algorithms are proposed for fast and efficient
transmission, encryption is used for security purposes and blurring is used by providing additional
layers of security. These algorithms are hybridized for having a robust and efficient security and
transmission over cloud storage system.
Application of Buckley-Leverett Equation in Modeling the Radius of Invasion i...IJERD Editor
A thorough review of existing literature indicates that the Buckley-Leverett equation only analyzes
waterflood practices directly without any adjustments on real reservoir scenarios. By doing so, quite a number
of errors are introduced into these analyses. Also, for most waterflood scenarios, a radial investigation is more
appropriate than a simplified linear system. This study investigates the adoption of the Buckley-Leverett
equation to estimate the radius invasion of the displacing fluid during waterflooding. The model is also adopted
for a Microbial flood and a comparative analysis is conducted for both waterflooding and microbial flooding.
Results shown from the analysis doesn’t only records a success in determining the radial distance of the leading
edge of water during the flooding process, but also gives a clearer understanding of the applicability of
microbes to enhance oil production through in-situ production of bio-products like bio surfactans, biogenic
gases, bio acids etc.
Gesture Gaming on the World Wide Web Using an Ordinary Web CameraIJERD Editor
- Gesture gaming is a method by which users having a laptop/pc/x-box play games using natural or
bodily gestures. This paper presents a way of playing free flash games on the internet using an ordinary webcam
with the help of open source technologies. Emphasis in human activity recognition is given on the pose
estimation and the consistency in the pose of the player. These are estimated with the help of an ordinary web
camera having different resolutions from VGA to 20mps. Our work involved giving a 10 second documentary to
the user on how to play a particular game using gestures and what are the various kinds of gestures that can be
performed in front of the system. The initial inputs of the RGB values for the gesture component is obtained by
instructing the user to place his component in a red box in about 10 seconds after the short documentary before
the game is finished. Later the system opens the concerned game on the internet on popular flash game sites like
miniclip, games arcade, GameStop etc and loads the game clicking at various places and brings the state to a
place where the user is to perform only gestures to start playing the game. At any point of time the user can call
off the game by hitting the esc key and the program will release all of the controls and return to the desktop. It
was noted that the results obtained using an ordinary webcam matched that of the Kinect and the users could
relive the gaming experience of the free flash games on the net. Therefore effective in game advertising could
also be achieved thus resulting in a disruptive growth to the advertising firms.
Hardware Analysis of Resonant Frequency Converter Using Isolated Circuits And...IJERD Editor
-LLC resonant frequency converter is basically a combo of series as well as parallel resonant ckt. For
LCC resonant converter it is associated with a disadvantage that, though it has two resonant frequencies, the
lower resonant frequency is in ZCS region[5]. For this application, we are not able to design the converter
working at this resonant frequency. LLC resonant converter existed for a very long time but because of
unknown characteristic of this converter it was used as a series resonant converter with basically a passive
(resistive) load. . Here, it was designed to operate in switching frequency higher than resonant frequency of the
series resonant tank of Lr and Cr converter acts very similar to Series Resonant Converter. The benefit of LLC
resonant converter is narrow switching frequency range with light load[6] . Basically, the control ckt plays a
very imp. role and hence 555 Timer used here provides a perfect square wave as the control ckt provides no
slew rate which makes the square wave really strong and impenetrable. The dead band circuit provides the
exclusive dead band in micro seconds so as to avoid the simultaneous firing of two pairs of IGBT’s where one
pair switches off and the other on for a slightest period of time. Hence, the isolator ckt here is associated with
each and every ckt used because it acts as a driver and an isolation to each of the IGBT is provided with one
exclusive transformer supply[3]. The IGBT’s are fired using the appropriate signal using the previous boards
and hence at last a high frequency rectifier ckt with a filtering capacitor is used to get an exact dc
waveform .The basic goal of this particular analysis is to observe the wave forms and characteristics of
converters with differently positioned passive elements in the form of tank circuits.
Simulated Analysis of Resonant Frequency Converter Using Different Tank Circu...IJERD Editor
LLC resonant frequency converter is basically a combo of series as well as parallel resonant ckt. For
LCC resonant converter it is associated with a disadvantage that, though it has two resonant frequencies, the
lower resonant frequency is in ZCS region [5]. For this application, we are not able to design the converter
working at this resonant frequency. LLC resonant converter existed for a very long time but because of
unknown characteristic of this converter it was used as a series resonant converter with basically a passive
(resistive) load. . Here, it was designed to operate in switching frequency higher than resonant frequency of the
series resonant tank of Lr and Cr converter acts very similar to Series Resonant Converter. The benefit of LLC
resonant converter is narrow switching frequency range with light load[6] . Basically, the control ckt plays a
very imp. role and hence 555 Timer used here provides a perfect square wave as the control ckt provides no
slew rate which makes the square wave really strong and impenetrable. The dead band circuit provides the
exclusive dead band in micro seconds so as to avoid the simultaneous firing of two pairs of IGBT’s where one
pair switches off and the other on for a slightest period of time. Hence, the isolator ckt here is associated with
each and every ckt used because it acts as a driver and an isolation to each of the IGBT is provided with one
exclusive transformer supply[3]. The IGBT’s are fired using the appropriate signal using the previous boards
and hence at last a high frequency rectifier ckt with a filtering capacitor is used to get an exact dc
waveform .The basic goal of this particular analysis is to observe the wave forms and characteristics of
converters with differently positioned passive elements in the form of tank circuits. The supported simulation
is done through PSIM 6.0 software tool
Amateurs Radio operator, also known as HAM communicates with other HAMs through Radio
waves. Wireless communication in which Moon is used as natural satellite is called Moon-bounce or EME
(Earth -Moon-Earth) technique. Long distance communication (DXing) using Very High Frequency (VHF)
operated amateur HAM radio was difficult. Even with the modest setup having good transceiver, power
amplifier and high gain antenna with high directivity, VHF DXing is possible. Generally 2X11 YAGI antenna
along with rotor to set horizontal and vertical angle is used. Moon tracking software gives exact location,
visibility of Moon at both the stations and other vital data to acquire real time position of moon.
“MS-Extractor: An Innovative Approach to Extract Microsatellites on „Y‟ Chrom...IJERD Editor
Simple Sequence Repeats (SSR), also known as Microsatellites, have been extensively used as
molecular markers due to their abundance and high degree of polymorphism. The nucleotide sequences of
polymorphic forms of the same gene should be 99.9% identical. So, Microsatellites extraction from the Gene is
crucial. However, Microsatellites repeat count is compared, if they differ largely, he has some disorder. The Y
chromosome likely contains 50 to 60 genes that provide instructions for making proteins. Because only males
have the Y chromosome, the genes on this chromosome tend to be involved in male sex determination and
development. Several Microsatellite Extractors exist and they fail to extract microsatellites on large data sets of
giga bytes and tera bytes in size. The proposed tool “MS-Extractor: An Innovative Approach to extract
Microsatellites on „Y‟ Chromosome” can extract both Perfect as well as Imperfect Microsatellites from large
data sets of human genome „Y‟. The proposed system uses string matching with sliding window approach to
locate Microsatellites and extracts them.
Importance of Measurements in Smart GridIJERD Editor
- The need to get reliable supply, independence from fossil fuels, and capability to provide clean
energy at a fixed and lower cost, the existing power grid structure is transforming into Smart Grid. The
development of a smart energy distribution grid is a current goal of many nations. A Smart Grid should have
new capabilities such as self-healing, high reliability, energy management, and real-time pricing. This new era
of smart future grid will lead to major changes in existing technologies at generation, transmission and
distribution levels. The incorporation of renewable energy resources and distribution generators in the existing
grid will increase the complexity, optimization problems and instability of the system. This will lead to a
paradigm shift in the instrumentation and control requirements for Smart Grids for high quality, stable and
reliable electricity supply of power. The monitoring of the grid system state and stability relies on the
availability of reliable measurement of data. In this paper the measurement areas that highlight new
measurement challenges, development of the Smart Meters and the critical parameters of electric energy to be
monitored for improving the reliability of power systems has been discussed.
Study of Macro level Properties of SCC using GGBS and Lime stone powderIJERD Editor
One of the major environmental concerns is the disposal of the waste materials and utilization of
industrial by products. Lime stone quarries will produce millions of tons waste dust powder every year. Having
considerable high degree of fineness in comparision to cement this material may be utilized as a partial
replacement to cement. For this purpose an experiment is conducted to investigate the possibility of using lime
stone powder in the production of SCC with combined use GGBS and how it affects the fresh and mechanical
properties of SCC. First SCC is made by replacing cement with GGBS in percentages like 10, 20, 30, 40, 50 and
by taking the optimum mix with GGBS lime stone powder is blended to mix in percentages like 5, 10, 15, 20 as
a partial replacement to cement. Test results shows that the SCC mix with combination of 30% GGBS and 15%
limestone powder gives maximum compressive strength and fresh properties are also in the limits prescribed by
the EFNARC.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Neuro-symbolic is not enough, we need neuro-*semantic*
International Journal of Engineering Research and Development (IJERD)
1. International Journal of Engineering Research and Development
e-ISSN: 2278-067X, p-ISSN: 2278-800X, www.ijerd.com
Volume 8, Issue 8 (September 2013), PP. 41-46
www.ijerd.com 41 | Page
Power Quality Improvement in Microgrid Using
Advanced Active Power Conditioner
1
B.Naresh, 2
V. K.R.Mohan Rao, 3
Y.Rambabu
1
PG Scholar, 2
Associate Professor, 3
Assistant Professor
1, 2, 3
Holy Mary Institute of Technology & Science
Abstract:- Wind energy conversion systems are now occupying important space in the research of renewable
energy sources with microgrid. The main challenge in wind power generation is power quality problem and their
connection with the distribution network in microgrid. The main factor behind poor power quality is the impact
of harmonics in current and voltage in power network. In microgrid the converter and rectifier are using to
convert AC-DC-AC to interconnection of wind power and load to microgrid. The converter and rectifier are
producing the significant harmonics. In this paper presents a three-phase Active Power Conditioner to improve
power quality in microgrids based on renewable energy. A microgrid is a weak electrical grid which can be
easily subject to disturbances. The Active Power Conditioner (APC) presented in this paper acts as an interface
between renewable energy sources and the AC bus of a microgrid and uses an improved control strategy, which
makes possible to inject energy in the microgrid, compensate the current harmonics and correct the power
factor. Simulation results show the validity of the innovative control strategy.
Keywords:- Active Power Conditioner, Microgrids, Renewable Energy, Current control, Harmonics
I. INTRODUCTION
Due to an increase in power demand and fossil fuel shortage, renewable energy supplies have become
an essential to full fill the energy demand in the age of technology. The wind power plants have huge
contribution to the production of renewable energy. Although wind power plant have a major contribution in
renewable energy, the power generated by wind turbines overtime is uneven due to the unpredictable nature of
their primary sources of power which increases the problems inherent to the integration of a great number of
wind turbines into microgrid. The contribution of wind power plants faces certain challenge like voltage and
frequency regulation [1].
In an electrical power system microgrid is the name given to a group of electric loads and power
generation from different sources like wind, solar etc. operation as a controllable system that inject electric
power to its local area and regional grid [2][3]. The microgrid play an important role to enhance local reliability,
increase efficiency, support local voltage, voltage sag correction, on provide uninterruptible power supply
function [4][5].
A possible solution to overcome the above mentioned drawback is to use the APC as a power interface
between the renewable energy sources and the AC bus of the microgrids as shown in Fig. 1. The APC has
proved to be an important alternative to compensate current and voltage disturbances in power distribution
systems [6], [7]. Different APC topologies have been presented in the technical literature [8], but most of them
are not adapted for microgrids applications.
Figure 1. APC for Microgrid applications
2. Power Quality Improvement in Microgrid Using Active Power Conditioner
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This paper presents an APC used to improve the power quality in a microgrid. The attention will be
mainly focused on the innovative control strategy, which allows injecting energy in the microgrid, compensating
the current harmonics, correcting the power factor and balancing the supply voltage at the PCC. The validity of
the control strategy has been proved through many simulation tests using SimPowerSystems from
MATLAB/SIMULINK.
II. MICROGRID STRUCTURE
The MicroGrid structure assumes an aggregation of loads and microsources operating as a single
system providing both power and heat. The majority of the microsources must be power electronic based to
provide the required flexibility to insure controlled operation as a single aggregated system. This control
flexibility allows the MicroGrid to present itself to the bulk power system as a single controlled unit, have plug-
and-play simplicity for each microsource, and meet the customers’ local needs. These needs include increased
local reliability and security.
Key issues that are part of the MicroGrid structure include the interface, control and protection
requirements for each microsource as well as MicroGrid voltage control, power flow control, load sharing
during islanding, protection, stability, and over all operation. The ability of the MicroGrid to operate connected
to the grid as well as smooth transition to and from the island mode is another important function.
Figure 2 illustrates the basic MicroGrid architecture. The electrical system is assumed to be radial with three
feeders – A, B, and C – and a collection of loads. The microsources are either microturbines or fuel cells
interfaced to the system through power electronics. The Point of Common Coupling (PCC) is on the primary
side of the transformer and defines the separation between the grid and the MicroGrid. At this point the
MicroGrid must meet the prevailing
interface requirements, such as defined in draft standard IEEE P1547.
The sources on Feeder A & B allow full exploration of situations where the microsources are placed
away from the common feeder bus to reduce line losses, support voltage and/or use its waste heat. Multiple
microsources on a radial feeder increase the problem of power flow control and voltage support along the feeder
when compared to all sources being placed at the feeder’s common bus, but this placement is key to the plug-
and-play concept. The feeders are usually 480 volts or smaller. Each feeder has several circuit breakers and
power and voltage flow controllers. The power and voltage controller near each microsource provides the
control signals to the source, which regulates feeder power flow and bus voltage at levels prescribed by the
Energy Manager. As downstream loads change, the local microsource’s power is increased or decreased to hold
the total power flow at the dispatched level.
Fig.2 MicroGrid Architecture
3. Power Quality Improvement in Microgrid Using Active Power Conditioner
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III. ACTIVE POWER CONDITIONER TOPOLOGY
The most utilised topology, to manage four currents, is four-leg converters [9]. This topology has
proved better controllability [10] than the classical three-leg four-wire converter but the latter is preferred
because of its lower number of power semiconductor devices. In this paper, it is shown that using an adequate
control strategy, even with a simple three-leg four-wire system, it is possible to mitigate disturbances like
voltage unbalance, THD and others. The topology of the investigated APC and its interconnection with the
microgrid is presented in Fig. 2. It consists of a three-leg four-wire voltage source inverter. In this type of
applications, the VSI operates as a current controlled voltage source. In order to provide the neutral point, two
capacitors are used to split the DC-link voltage and tie the neutral point to the mid-point of the two capacitors.
This topology allows the current to flow in both directions through the switches and the capacitors, causing
voltage deviation between the DC capacitors.
𝑖𝑓𝑎 + 𝑖𝑓𝑏 + 𝑖𝑓𝑐 = 𝑖𝑓𝑁 ……………………(1)
where:
𝑖𝑓𝑎 , 𝑖𝑓𝑏 , 𝑖𝑓𝑐 are phase APC currents and ifN is the APC neutral current.
Therefore, the total DC voltage will oscillate not only at the switching frequency but also at the
corresponding frequency of the neutral current. As shown in [2], if the current control is made by hysteresis, the
above mentioned drawback can be limited with a dynamic offset level added to both limits of the hysteresis
band.
For the investigated topology presented in Fig. 3, the current at (PCC) is:
𝑖𝑙𝑥 + 𝑖𝑓𝑥 = 𝑖 𝑥 …………………………….(2)
Figure 2. APC topology
𝑖 𝑥 , 𝑖𝑙𝑥 , 𝑖𝑓𝑥 are the microgrid side current, the load current, and the APC current respectively. The x index points
the a, b and c current phases.
The instantaneous load current is:
𝑖𝑙𝑥 = 𝑖𝑙𝑥
1
+ 𝑖𝑙𝑥𝑘 + 𝑖𝑙𝑥𝑞 …………………………..(3)
where:
- 𝑖𝑙𝑥
1
the fundamental active current component;
-𝑖𝑙𝑥𝑘 the addition of current harmonics;
- 𝑖𝑙𝑥𝑞 the reactive current component.
The three-phase APC current is given by:
𝑖𝑓𝑥 = 𝑖𝑓𝑥
1
+ 𝑖𝑓𝑥
~
………………………………..(4)
𝑖𝑓𝑥
1
- the fundamental conditioner current component;
𝑖𝑓𝑥
~
- the deforming component of the current.
As shown in Fig. 3 the current drawn from the grid has to be sinusoidal and moreover, in phase with the voltage
at PCC. Consequently, the control strategy for the APC has to be designed in order to ensure a sinusoidal wave
for the grid current (ix).
4. Power Quality Improvement in Microgrid Using Active Power Conditioner
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𝑖𝑙𝑥
1
+ 𝑖𝑙𝑥𝑘 + 𝑖𝑙𝑥𝑞 + 𝑖𝑓𝑥
1
+ 𝑖𝑓𝑥
~
= 𝑖 𝑥 …………………………(5)
The APC switches generate undesirable current harmonics around the switching frequency and its
multiples. Considering the switching frequency of the APC sufficiently high, these undesirable current
harmonics can be filtered with the LR passive filter.
IV. CONTROL OF THE APC
A. Control Strategy
There are many ways to design a control algorithm for an APC [11]. Generally, the controller design is
made considering that the grid voltage at the PCC is balanced. In a microgrid, the supply voltage itself can be
distorted and/or unbalanced. Consequently, the controller of an APC used to improve the power quality in the
microgrid has to be designed according to the weakness of this kind of grid.
The proposed control algorithm is a compensation method that makes the APC compensate the current
of a non-linear load by forcing the microgrid side current to become sinusoidal and balanced (Fig. 3). The
controller requires the three-phase grid current (ia, ib, ic), the three-phase voltage at the Pcc (va, vb, vc) and the
DC-link voltage (VDC). As shown in Fig. 4, the sinusoidal waveform and the phase of the grid current reference
(ia*, ib*, ic*) comes from the line voltage thanks to a PLL. The magnitude of the same current is obtained by
passing the error signal (ε) between the DC-link voltage (Vdc) and a reference voltage (V*
dc) through a PI
controller.
Figure 4. APC control strategy
Using this magnitude and phase displacement of 120° and 240° respectively, the reference three-phase
grid currents 𝑖 𝑎
∗
, 𝑖 𝑏
∗
𝑎𝑛𝑑 𝑖 𝑐
∗
can be expressed as:
B. Switching control
As shown in Fig. 4, the hysteresis control has been used to keep the controlled current inside a defined
band around the references. The status of the switches is determined according to the error. When the current is
increasing and the error exceeds a certain positive value, the status of the switches changes and the current
begins to decrease until the error reaches a certain negative value. Then, the switches status changes again.
Compared with linear controllers, the non-linear ones based on hysteresis strategies allow faster dynamic
response and better robustness with respect to the variation of the non-linear load. A drawback of the hysteresis
5. Power Quality Improvement in Microgrid Using Active Power Conditioner
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strategies is the switching frequency which is not constant and can generate a large side harmonics band around
the switching frequency.
To avoid this drawback, the switching frequency can be fixed using different solutions like variable
hysteresis bandwidth or modulated hysteresis. But this is not the object of this paper.
V. SIMULATION RESULTS
The simulation was performed on the MATLAB/ SIMULINK package. Simulink is a software package
for modelling, simulating and analyzing dynamic systems. It supports linear and nonlinear systems, modeled in
continuous time, sampled time, or a hybrid of the two. Systems can also be multirate, i.e., having different parts
that are sampled or updated at different rates. In this the simulink models of the shunt active filter with
hysteresis current controller are given along with simulation results.
An extensive simulation study is carried out using MATLAB/Simulink in order to verify the proposed control
strategy. To achieve balanced sinusoidal grid currents at unity power factor, the 3-leg grid interfacing inverter is
actively controlled using renewable energy source. The simulation results are grouped and presented according
to the following power quality indicators: THD(Total Harmonic Distortion),power factor and unbalanced load.
A. Harmonics compensation
During this case study, the APC is investigated using a three-phase diode bridge rectifier with a 60Ω
resistor in series with a 0.1mH inductor at the DC side.
Fig.5- shows the nonlinear load current
Fig. 6-shows the APC side current
Fig.7 shows the source side current
Fig.5,6,7 shows the currents at the PCC. As can be seen, most of the current required by the load is
injected by the APC and the balance comes from the microgrid, The current absorbed by the rectifier is not
sinusoidal
B. Power factor correction
The second case study shows the effectiveness of the APC to compensate the power factor. The power
faction can be controlled with the capacitor banks, but this is the manual operation. In distorted conditions the
results are power and also the capacitor life is shorter. So maintenance cost also high. For this case study, the
load is composed by a three-phase inductor in series with a three-phase resistor and requires about 3KW active
power and 4kVAR reactive power.
6. Power Quality Improvement in Microgrid Using Active Power Conditioner
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Fig.8- Before Compensation
Fig.9- After Compensation
Fig.8 illustrates the load current, the microgrid side current and the supply voltage respectively at the
PCC of phase-a. As shown in fig.9 the measured power factor between the load current and the supply voltage is
0.58. Thanks to the proposed control strategy, the APC is able to impose a unity power factor between the
microgrid side currents and the supply voltage. The phase of the microgrid side currents is inverted relatively to
the phase of supply voltages at the PCC because the power injected by the APC exceeds the power required by
the load. Consequently, the surplus renewable energy is injected into the microgrid.
VI. CONCLUSIONS
In this paper, an APC used to improve power quality in microgrids based on renewable energy has
been presented. The APC is controlled using an innovative control strategy allowing the line current at the point
of common coupling to be balanced and sinusoidal even when the load is unbalanced.
This approach presents the following advantages:
The control system is simpler, because only three sinusoidal waveforms have to be generated for the
reference currents.
These sinusoidal waveforms to control the current are generated in phase with the main supply,
allowing unity power-factor operation.
The control of the three-phase line current enables the three-phase voltage balance at the PCC, allowing
excellent regulation characteristics.
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[1]. Majid mumtaz, “ Harmonic Domain modeling of wind based microgrid”, university of Glasgow, 2012.
[2]. Dvorsky E, Hejtmankova P. Skorpil J. “ Control of micro-grids with renewable power sources”, IEEE,
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[3]. Lasseter R.H. micrgrids In: IEEE power eng SOC transindistrib conf. pp 305-308,2002
[4]. Marnay c, Venkataramana G, microgrids in the evolving electrical generation and delivery
infrastructure. In:IEEE power eng SOC gen meet: pp 18-22, 2006.
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[6]. M. Abdusalama, P. Poureb, S. Karimia and S. Saadatea “New digital reference current generation for
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[8]. B. Singh, K. Al-Haddad, A. Chandra “A Review of Active Filters for Power Quality Improvement”
IEEE Transactions on Power Electronics, vol. 46, pp. 960-971, October 1999.
[9]. J. Chen, F. Liu , S. Mei, “Nonlinear disturbance attenuation control for four-leg active power filter
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[10]. M. Ucara and E. Ozdemir “Control of a 3-phase 4-leg active power filter under non-ideal mains voltage
condition,” Electric Power Systems Research, vol. 78, pp. 58-73, January 2008.
[11]. A. Zhikang, S. Wenji Z. Ruixiang and F. Chunming Tu “Development of Hybrid Active Power Filter
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