In modern society every sector needs continuous power on demand. To achieve this voltage,
current and frequency, these parameters of the power system should be at rated values. Because of
remote generation, transmission and distribution, we are failing to receive the reliable power. To
overcome this problem, the Distribution energy sources (DES) become more suitable solution. This
generated power from DES is supplied to local loads and this can be connected to the main grid
through the Micro-Grid (MG). Micro-grids will operate in two modes, A Grid-connected mode and in
an Islanded mode. During islanding mode, one Distributed Generation (DG) unit should share output
generation power with other unit in exact accordance with the load. Need to control Real and Reactive
power effectively for the load to operate without disturbance. Hence in the present work, Voltage
Source Inverter (VSI) and Proportional Integral Derivative(PID) controller in power conversion
process to get required real and reactive power for the normal operation of micro-grid. The proposed
method has been applied to a designed test Simulink model for different types of Grid connected and
Isolated modes. The simulation results obtained show that, this method can improves the reliability and
smooth operation of the micro-grid system.
Autonomous microgrid based parallel inverters using droop controller for impr...journalBEEI
The existing microgrid has become a challenge to the sustainable energy source to provide a better quality of power to the consumer. To build a reliable and efficient microgrid, designing a droop controller for the microgrid is of utmost importance. In this paper, multiple voltage source inverters connected in parallel using an active power-frequency/reactive power-voltage droop scheme. The proposed method connected to two distributed generators local controllers, where each unit consists of a droop controller with an inner voltage-current controller and a virtual droop controller. By adding this controller to the microgrid reliability and load adaptability of an islanded system can be improved. This concept applied without any real-time communication to the microgrid. Thus, simulated using MATLAB/Simulink, the obtained results prove the effectiveness of the autonomous operation's microgrid model.
Seamless Transitions between Grid-Connected and Stand-Alone Operations of Dis...IJERD Editor
Control of the Distributed Generation (DG) system is important in both grid-connected and standalone
modes and the system stability becomes very crucial during the transfer between these two modes. If the
system does not have a proper transfer procedure, severe transient voltages or currents will occur, which may
damage the entire system. A seamless transfer can ensure smooth operation and quick attainment of steady state.
In order to solve these transition problems, this paper presents the development and test of a control strategy for
DG capable of working in grid-connected and intentional islanding connection modes with seamless transitions
from both operational modes.
Improving Voltage Profile of Islanded Microgrid using PI Controller IJECEIAES
In islanding operating mode of microgrid, the voltage and frequency of system must be maintained by the microgrid, or else the system will crumble due to the characteristics of different distributed generators (DG) utilized in microgrid. The voltage and frequency lost provision when main grid is disconnected. This paper presents PI controller based voltage controller to regulate voltage to its normal condition. The controller is proposed to be utilized individually with each distributed generator (DG) in microgrid. The controller compares inverter output voltage with voltage at point of common coupling (PCC) and its output is feed to PWM pulse generator to generate appropriate pulses for inverter to regulate voltage to its nominal value. The simulation results of proposed system are shown using MATLAB/Simulink platform.
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.
The proposed work comprises of an MPPT controlled Photovoltaic (PV) source, in conjunction with a supercapacitor, cascaded with a Sliding Mode Controlled (SMC) Inverter, supplying variable linear and nonlinear loads. The effects of varying solar irradiation and its intermittency have been effectively managed by the MPPT controlled boost converter and charge controlled supercapacitor respectively. The charge controller bucks and boosts the terminal voltage and realizes the power flow in a bidirectional manner. Seamless action has been obtained by the proposed model under varying irradiation and for varying load conditions. The performance of the SMC controlled Inverter, when compared with a PI controlled Inverter, has been found to be superior in terms of power quality and robustness of the supply system.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
In modern society every sector needs continuous power on demand. To achieve this voltage,
current and frequency, these parameters of the power system should be at rated values. Because of
remote generation, transmission and distribution, we are failing to receive the reliable power. To
overcome this problem, the Distribution energy sources (DES) become more suitable solution. This
generated power from DES is supplied to local loads and this can be connected to the main grid
through the Micro-Grid (MG). Micro-grids will operate in two modes, A Grid-connected mode and in
an Islanded mode. During islanding mode, one Distributed Generation (DG) unit should share output
generation power with other unit in exact accordance with the load. Need to control Real and Reactive
power effectively for the load to operate without disturbance. Hence in the present work, Voltage
Source Inverter (VSI) and Proportional Integral Derivative(PID) controller in power conversion
process to get required real and reactive power for the normal operation of micro-grid. The proposed
method has been applied to a designed test Simulink model for different types of Grid connected and
Isolated modes. The simulation results obtained show that, this method can improves the reliability and
smooth operation of the micro-grid system.
Autonomous microgrid based parallel inverters using droop controller for impr...journalBEEI
The existing microgrid has become a challenge to the sustainable energy source to provide a better quality of power to the consumer. To build a reliable and efficient microgrid, designing a droop controller for the microgrid is of utmost importance. In this paper, multiple voltage source inverters connected in parallel using an active power-frequency/reactive power-voltage droop scheme. The proposed method connected to two distributed generators local controllers, where each unit consists of a droop controller with an inner voltage-current controller and a virtual droop controller. By adding this controller to the microgrid reliability and load adaptability of an islanded system can be improved. This concept applied without any real-time communication to the microgrid. Thus, simulated using MATLAB/Simulink, the obtained results prove the effectiveness of the autonomous operation's microgrid model.
Seamless Transitions between Grid-Connected and Stand-Alone Operations of Dis...IJERD Editor
Control of the Distributed Generation (DG) system is important in both grid-connected and standalone
modes and the system stability becomes very crucial during the transfer between these two modes. If the
system does not have a proper transfer procedure, severe transient voltages or currents will occur, which may
damage the entire system. A seamless transfer can ensure smooth operation and quick attainment of steady state.
In order to solve these transition problems, this paper presents the development and test of a control strategy for
DG capable of working in grid-connected and intentional islanding connection modes with seamless transitions
from both operational modes.
Improving Voltage Profile of Islanded Microgrid using PI Controller IJECEIAES
In islanding operating mode of microgrid, the voltage and frequency of system must be maintained by the microgrid, or else the system will crumble due to the characteristics of different distributed generators (DG) utilized in microgrid. The voltage and frequency lost provision when main grid is disconnected. This paper presents PI controller based voltage controller to regulate voltage to its normal condition. The controller is proposed to be utilized individually with each distributed generator (DG) in microgrid. The controller compares inverter output voltage with voltage at point of common coupling (PCC) and its output is feed to PWM pulse generator to generate appropriate pulses for inverter to regulate voltage to its nominal value. The simulation results of proposed system are shown using MATLAB/Simulink platform.
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.
The proposed work comprises of an MPPT controlled Photovoltaic (PV) source, in conjunction with a supercapacitor, cascaded with a Sliding Mode Controlled (SMC) Inverter, supplying variable linear and nonlinear loads. The effects of varying solar irradiation and its intermittency have been effectively managed by the MPPT controlled boost converter and charge controlled supercapacitor respectively. The charge controller bucks and boosts the terminal voltage and realizes the power flow in a bidirectional manner. Seamless action has been obtained by the proposed model under varying irradiation and for varying load conditions. The performance of the SMC controlled Inverter, when compared with a PI controlled Inverter, has been found to be superior in terms of power quality and robustness of the supply system.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
This article proposes a novel scheme to improve the doubly-fed induction generator (DFIG) behavior during grid fault. The DFIG’s are sensitives to voltage variations when abrupt variations of the wind velocity arrive. For enhancing DFIG behavior, protecting the converters, and smoothing the fluctuations power output of the DFIG under sag voltage; a novel hybrid energy storage system scheme and its controller are proposed. The main advantages of our approach are a faster response and suppressing overvoltage on DC bus and globally less stress in the storage system. The control structure decreases the tiredness on the battery and restores the DC bus voltage rapidly, globally the battery system operating time increases. The results obtained by simulations in MATLAB validate the benefits of the suggested control.
A study of voltage regulation in microgrid using a DSTATCOMjournalBEEI
A well-prepared abstract enables the reader to identify the basic content. This paper presents the solution of voltage fluctuations in urgent situations by providing voltage and reactive support from a distribution static synchronous compensator (DSTATCOM) in the grid. Also, it analyses the influences of DSTATCOM as a voltage controller and compares the system performance with and without DSTATCOM. The DSTATCOM is used in the study to maintain voltage in the microgrid (MG) to be around the rated value after Microgrid disturbance. A successful simulink model of the photovoltaic (PV) system and the proposed DSTATCOM are illustrated to work together as the Microgrid. Microgrids could provide unique resilience and reliability when the environment encountered with less water, higher temperatures, more frequent and harsh wildfires, and severe weather events. The proposed DSTATCOM was installed in different locations in the MG and the best location was chosen to achieve the goal of improved power quality and efficiency. In this paper, two scenarios are discussed with and without DSTATCOM. The simulation results show the difference between the MG with and without DSTATCOM and how the DSTATCOM can amplify power quality in the Microgrid. The proposed DSTATCOM has the capability to improve dampen power oscillations during transit events.
Control strategies for seamless transfer between the grid-connected and isla...IJECEIAES
Design of control strategies for Distributed generation systems is very important to achieve smoother transition between the grid connected and islanding modes of operation. The transition between these two modes of operation should be seamless, without any severe transients during the changeover. In this paper, two different control strategies namely inverter output current control and indirect grid current control for the seamless transfer between the modes of operation has been explored for the suitability. The design and analysis of the cascaded control loops based on Proportional Integral (PI) controller has been dealt in detail for both inverter output current control and indirect grid current control strategy. Control parameters are designed using the control system toolbox in MATLAB. A 10kW grid connected microgrid system has been designed and simulated in MATLAB/Simulink and the results are presented under grid connected operation, islanding operation and the transition between the modes considering fault condition in the grid side. The simulation studies are carried out using both the control strategies and the results are presented to validate the design methodology.
PID Compensator Control Scheme of Synchronous Buck DC-DC Converter with ZVS L...IJRES Journal
This paper deals with PID compensator control of Synchronous Rectifier (SR) Buck Converter to improve its conversion efficiency under different load conditions with the help of a Zero Voltage Switching(ZVS)Logic Circuit. Since the freewheeling diode is replaced by a high frequency switch MOSFET in this buck configuration, the SR control technique itself will be sufficient under heavy load condition to attain better normal mode performance. However, this technique does not hold well in light load condition, due to increased switching losses. A newPID compensator control techniqueis introduced in the paper will enable synchronous buck converter to realize ZVS, while feeding light load. This is also cost effective and highly efficient simple control method without use of extra auxiliary switches and RLC components. This control technique also proved to be efficient under input voltage variations. Simulation is done for proving stabilization provided by the PID compensator with the help of ZVS logic circuit for synchronous rectifier (SR) buck converter in MATLAB Simulink.
Fuzzy Based Analysis of Inverter Fed Micro Grid in Islanding Operation-Experi...IJPEDS-IAES
Islanding operation in essence connotes isolating part of a power system not unlike distributed generation. This thesis puts forward fuzzy logic controller for inverter fed micro-grid in islanding operations which is assessed using hardware implementation. It’s assisted by power electronics which imparts the control and flexibility essential for the micro grid concept. A correctly designed controller guarantees that the micro grid can meet its utility’s demands. The efficacy and robustness is deliberated in the design of fuzzy system. The testing is performed by employing hardware components namelyATMEGA-328microcontroller, TLP250 opto-coupler and a MOSFET circuit. The test results demonstrate very good consistency and show noteworthy implications of the control of micro grid using inverters and fuzzy controllers.
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.
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
Enhanced dynamic performance of grid feeding distributed generation under va...IJECEIAES
Controlling weak grid-connected systems is very challenging. In transient, frequency and voltage oscillations may lead to voltage and/or frequency stability problems and finally lead to system collapse. During steady-state operation and at the point of common coupling (PCC), voltage degradation and grid voltage background harmonics restrict the inverter's functionality, reduce the power flow capability and cause poor power quality. With weak grid connection, grid impedance variance will contaminate the voltage waveform by harmonics and augment the resonance, destabilizing the inverter operation. In this paper, complete mathematical modeling is carried out and state feedback-plus-integral control is implemented to support the stabilization of the system. The proposed controller is adopted to provide a smooth transient under sudden load change by controlling the injected grid current under different grid inductance values. Furthermore, the proposed control is used to reduce the order and size of the inverter output filter while maintaining system stability. The proposed control has been compared with the conventional proportional integral (PI) controller under different scenarios to validate its effectiveness and to strengthen its implementation as a simple controller for distributed generator applications.
Modeling and simulation for PV, Fuel cell Based MICROGRID under Unbalanced L...IJMER
Distributed generation has attracted great attention in recent years, thanks to the progress
in new-generation technologies and advanced power electronics. The Microgrid has been a successful
example by integrating various generation sources with the existing power distribution network
through power electronic converters. This paper proposes a PV, Fuel cell based microgrid and a new
control strategy for the islanded operation of a multi-bus medium voltage (MV) microgrid. The
proposed control strategy of each DG comprises a proportional resonance (PR) controller with an
adjustable resonance frequency, a droop control strategy, and a negative-sequence impedance
controller (NSIC). The PR and droop controllers are, respectively, used to regulate the load voltage
and share the average power components among the DG units. The NSIC is used to effectively
compensate the negative-sequence currents of the unbalanced loads and to improve the performance
of the overall microgrid system. Moreover, the NSIC minimizes the negative-sequence currents in the
MV lines and thus, improving the power quality of the microgrid. The performance of the proposed
control strategy is verified with PV, Fuel cell inputs by using digital time-domain simulation studies in
the MATLAB/SIMULINK software environment
Control of grid connected inverter system for sinusoidal current injection wi...ijiert bestjournal
The control strategy for the grid connected inverter (GCI) during abnormal conditions like voltage sag,swell and line to ground fault has been presented. The strategy adopted here operates even during faulty conditions,unlike the conventional controller which fails to operate during fault y conditions. The Multi-Reference Frame (MRF) PI Controller is used for this purpose. In order to study the D ynamic Performance of the system,it is simulated in Matlab Simulink environment. The overall system is simulated for normal condition that is without the presence of fault,and with the presence of fault. The performance is also studied during abnormal conditions of the grid and its results are analyzed. The simulat ion results exhibit improved performance of the system during normal as well as abnormal conditions.
Analysis of Low Frequency Oscillations in Autonomous Microgrid in Staic and D...Godwin Lobo
This presentation gives a overview of my B.E. final project we were working on in 2016.The hardware implementation and MATLAB simulation were main objectives.Hope you find it useful in your research.Use the reference given at the end of the slides.
for any more info please contact me- 7745058138-godwin1994lobo@gmail.com
The primary focus of the journal is on Information Technology and Computer Engineering. This suggests that the journal covers a wide range of topics within these disciplines.
The International Journal of Engineering and Science (IJES)theijes
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.
This article proposes a novel scheme to improve the doubly-fed induction generator (DFIG) behavior during grid fault. The DFIG’s are sensitives to voltage variations when abrupt variations of the wind velocity arrive. For enhancing DFIG behavior, protecting the converters, and smoothing the fluctuations power output of the DFIG under sag voltage; a novel hybrid energy storage system scheme and its controller are proposed. The main advantages of our approach are a faster response and suppressing overvoltage on DC bus and globally less stress in the storage system. The control structure decreases the tiredness on the battery and restores the DC bus voltage rapidly, globally the battery system operating time increases. The results obtained by simulations in MATLAB validate the benefits of the suggested control.
A study of voltage regulation in microgrid using a DSTATCOMjournalBEEI
A well-prepared abstract enables the reader to identify the basic content. This paper presents the solution of voltage fluctuations in urgent situations by providing voltage and reactive support from a distribution static synchronous compensator (DSTATCOM) in the grid. Also, it analyses the influences of DSTATCOM as a voltage controller and compares the system performance with and without DSTATCOM. The DSTATCOM is used in the study to maintain voltage in the microgrid (MG) to be around the rated value after Microgrid disturbance. A successful simulink model of the photovoltaic (PV) system and the proposed DSTATCOM are illustrated to work together as the Microgrid. Microgrids could provide unique resilience and reliability when the environment encountered with less water, higher temperatures, more frequent and harsh wildfires, and severe weather events. The proposed DSTATCOM was installed in different locations in the MG and the best location was chosen to achieve the goal of improved power quality and efficiency. In this paper, two scenarios are discussed with and without DSTATCOM. The simulation results show the difference between the MG with and without DSTATCOM and how the DSTATCOM can amplify power quality in the Microgrid. The proposed DSTATCOM has the capability to improve dampen power oscillations during transit events.
Control strategies for seamless transfer between the grid-connected and isla...IJECEIAES
Design of control strategies for Distributed generation systems is very important to achieve smoother transition between the grid connected and islanding modes of operation. The transition between these two modes of operation should be seamless, without any severe transients during the changeover. In this paper, two different control strategies namely inverter output current control and indirect grid current control for the seamless transfer between the modes of operation has been explored for the suitability. The design and analysis of the cascaded control loops based on Proportional Integral (PI) controller has been dealt in detail for both inverter output current control and indirect grid current control strategy. Control parameters are designed using the control system toolbox in MATLAB. A 10kW grid connected microgrid system has been designed and simulated in MATLAB/Simulink and the results are presented under grid connected operation, islanding operation and the transition between the modes considering fault condition in the grid side. The simulation studies are carried out using both the control strategies and the results are presented to validate the design methodology.
PID Compensator Control Scheme of Synchronous Buck DC-DC Converter with ZVS L...IJRES Journal
This paper deals with PID compensator control of Synchronous Rectifier (SR) Buck Converter to improve its conversion efficiency under different load conditions with the help of a Zero Voltage Switching(ZVS)Logic Circuit. Since the freewheeling diode is replaced by a high frequency switch MOSFET in this buck configuration, the SR control technique itself will be sufficient under heavy load condition to attain better normal mode performance. However, this technique does not hold well in light load condition, due to increased switching losses. A newPID compensator control techniqueis introduced in the paper will enable synchronous buck converter to realize ZVS, while feeding light load. This is also cost effective and highly efficient simple control method without use of extra auxiliary switches and RLC components. This control technique also proved to be efficient under input voltage variations. Simulation is done for proving stabilization provided by the PID compensator with the help of ZVS logic circuit for synchronous rectifier (SR) buck converter in MATLAB Simulink.
Fuzzy Based Analysis of Inverter Fed Micro Grid in Islanding Operation-Experi...IJPEDS-IAES
Islanding operation in essence connotes isolating part of a power system not unlike distributed generation. This thesis puts forward fuzzy logic controller for inverter fed micro-grid in islanding operations which is assessed using hardware implementation. It’s assisted by power electronics which imparts the control and flexibility essential for the micro grid concept. A correctly designed controller guarantees that the micro grid can meet its utility’s demands. The efficacy and robustness is deliberated in the design of fuzzy system. The testing is performed by employing hardware components namelyATMEGA-328microcontroller, TLP250 opto-coupler and a MOSFET circuit. The test results demonstrate very good consistency and show noteworthy implications of the control of micro grid using inverters and fuzzy controllers.
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.
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
Enhanced dynamic performance of grid feeding distributed generation under va...IJECEIAES
Controlling weak grid-connected systems is very challenging. In transient, frequency and voltage oscillations may lead to voltage and/or frequency stability problems and finally lead to system collapse. During steady-state operation and at the point of common coupling (PCC), voltage degradation and grid voltage background harmonics restrict the inverter's functionality, reduce the power flow capability and cause poor power quality. With weak grid connection, grid impedance variance will contaminate the voltage waveform by harmonics and augment the resonance, destabilizing the inverter operation. In this paper, complete mathematical modeling is carried out and state feedback-plus-integral control is implemented to support the stabilization of the system. The proposed controller is adopted to provide a smooth transient under sudden load change by controlling the injected grid current under different grid inductance values. Furthermore, the proposed control is used to reduce the order and size of the inverter output filter while maintaining system stability. The proposed control has been compared with the conventional proportional integral (PI) controller under different scenarios to validate its effectiveness and to strengthen its implementation as a simple controller for distributed generator applications.
Modeling and simulation for PV, Fuel cell Based MICROGRID under Unbalanced L...IJMER
Distributed generation has attracted great attention in recent years, thanks to the progress
in new-generation technologies and advanced power electronics. The Microgrid has been a successful
example by integrating various generation sources with the existing power distribution network
through power electronic converters. This paper proposes a PV, Fuel cell based microgrid and a new
control strategy for the islanded operation of a multi-bus medium voltage (MV) microgrid. The
proposed control strategy of each DG comprises a proportional resonance (PR) controller with an
adjustable resonance frequency, a droop control strategy, and a negative-sequence impedance
controller (NSIC). The PR and droop controllers are, respectively, used to regulate the load voltage
and share the average power components among the DG units. The NSIC is used to effectively
compensate the negative-sequence currents of the unbalanced loads and to improve the performance
of the overall microgrid system. Moreover, the NSIC minimizes the negative-sequence currents in the
MV lines and thus, improving the power quality of the microgrid. The performance of the proposed
control strategy is verified with PV, Fuel cell inputs by using digital time-domain simulation studies in
the MATLAB/SIMULINK software environment
Control of grid connected inverter system for sinusoidal current injection wi...ijiert bestjournal
The control strategy for the grid connected inverter (GCI) during abnormal conditions like voltage sag,swell and line to ground fault has been presented. The strategy adopted here operates even during faulty conditions,unlike the conventional controller which fails to operate during fault y conditions. The Multi-Reference Frame (MRF) PI Controller is used for this purpose. In order to study the D ynamic Performance of the system,it is simulated in Matlab Simulink environment. The overall system is simulated for normal condition that is without the presence of fault,and with the presence of fault. The performance is also studied during abnormal conditions of the grid and its results are analyzed. The simulat ion results exhibit improved performance of the system during normal as well as abnormal conditions.
Analysis of Low Frequency Oscillations in Autonomous Microgrid in Staic and D...Godwin Lobo
This presentation gives a overview of my B.E. final project we were working on in 2016.The hardware implementation and MATLAB simulation were main objectives.Hope you find it useful in your research.Use the reference given at the end of the slides.
for any more info please contact me- 7745058138-godwin1994lobo@gmail.com
The primary focus of the journal is on Information Technology and Computer Engineering. This suggests that the journal covers a wide range of topics within these disciplines.
The International Journal of Engineering and Science (IJES)theijes
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.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
Gen AI Study Jams _ For the GDSC Leads in India.pdf
sikder2018.pdf
1. Fractional Order Robust PID Controller Design for Voltage
Control of Islanded Microgrid
Abstract—This paper emblems the application of fractional
order PID (FOPID) controller into a single phase islanded
microgrid having a single power source to control the fluc-
tuations in its output voltage. The proffered controller has
adaptability in devise as the controller provides more parame-
ters than integer Order PID controller (IOPID)to tune it. The
proffered controller is devised using Nelder-Mead optimization
technique. Use of the optimization technique gives increased
performance of the system. The controller is applied into the
system under uncertainties and different load settings. After
assessment of performance, it is observed that the application
of the proffered controller can cut down the voltage fluctuations
of the system and afford fast response with robust performance.
Index Terms—Control, Microgrid, Fractional Order PID.
1. Introduction
The appetence of an uninterrupted flow of low-cost elec-
tricity is rising with the advancement of modern technology
and distributed energy production systems are being set up
in low exhaustion areas for the realization of the appe-
tence [1]. These types of energy supplies are worthwhile
as they are occupied adjacent to the consumer loads [2].
Green energy appliances like geothermal power, PV solar
generators, wind generators, biogas, hydroelectric plants are
some of the distributed generators [3]. These distributed
energy generators get associated to energy storages as well
as loads and construct a system which is known as microgrid
system [1]. Microgrid gets connected to the main grid to
meet the appetence of the electric energy. The construction
of microgrid includes slightly one distributed energy gen-
erator, energy reservoir and consumer loads. The system
gets more responsive, robust and rapid than conventional
synchronous generators because of getting interfaced with
power electronic converters [4]. Grid connected mode and
islanded mode are two operational conditions followed by
the microgrid [5], [6]. Point of common coupling (PCC) is
a system that is used by microgrid to get connected to the
main grid in grid connected mode. The main gets support
by using the grid connected mode and it also reduces the
burden on nonrenewable energy resources. In this mode,
Voltage and frequency ratings of the supply line comes from
the main grid and the microgrid system can maintain both
discharging and receiving network with the main grid. In
the act of breakdown of the regular grid, the islanded mode
supports the significant loads and supply continuous power
to the associated loads. These breakdown occurs due to the
poor power quality, voltage collapse, faults in the regular
grid and also for natural calamities. It supports both main
grid and regional loads by increasing the accuracy of the
generated electric power.
Sustainable energy resources make the islanded microgrid
system disparate from the regular grid control [7]. These
resources are the instigators for DG units. The conduction
of the sustainable energy resources rely on different factors
like weather, speed of wind, power of sunlight, speed of
water flow etc and these factors make the output voltage of
the microgrid system to fluctuate and cause risky action in
use [8], [9].
Number of control schemes have been proffered to control
the microgrid voltage. A leading scheme is droop control
method [10].It restricts the precision in sharing power due
to divergence in voltage. Decentralized control [11] and
Distributed control [12] schemes have been brought in to
improve the precision in sharing power by removing voltage
divergence. It suffers the low bandwidth in communication
network.
Hierarchical control scheme provides steady-state perfor-
mance and advanced bandwidth in the control [13] of mi-
crogrid voltage. The performance of this controller depends
on 3 consecutive levels. The levels can be termed as pri-
mary control, secondary control and tertiary control. It may
deviates the performance due to fall down of one level that
ensure the poor performance of MG.
Linear quadratic regulator (LQR) [14], [15] can be
used in getting better voltage regulation and simultaneous
load sharing in microgrids. The system gets shortage in
robustness while working with LQR controller, if the plant
dynamics is shifted [16].
Model Predictive Controller (MPC) have been proffered
for robust performance in microgrid [17] . The design of
MPC controller depends on order of the system. Controller
of higher order is needed for controlling higher order system
and this phenomenon can feel necessity for having progres-
sive system of digital signal processing.
Proportional-Integral-Derivative (PID) controllers have
been proffered to regulate voltage in microgrid [5]. The PID
controller has the major drawback of having lower band-
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2. Voltage Source
Inverter
dc
v
L
C
line
R
Load
G
v
L
i G
i
C
i
dc
s v
v
)LJSinglePhaseIslandedMicrogrid
width and very low in robustness when the plant dynamics
is shifted [18].
The intention of this article is solely to compensate the
fluctuation of microgrid voltage in various load dynamics.
Variation in load dynamics may endure a lot of fluctuation
in microgrid voltage that may cause risky activity of the MG
system . Motivated by this fluctuation problem in microgrid,
a high performance robust apprehend controller is proffered
in this article. benefaction of this article is to devise the
fractional order PID (FOPID) controller for maintaining the
performance of microgrid system. The proffered controller
may provide more tuning parameters compared to integer
order control. The number of tuning parameter provides the
minimum level of steady state error and higher bandwidth.
The benefits of proposed controller is its design flexibility,
obvious implemention and independence of the system or-
der. Parameter values of proffered controller has been found
using trial and error method with respect to the appropriate
performance indication.
The remaining of the article has been standardized as
follows. Modeling of the islanded microgrid is presented in
section II. Section III describes the devision of the FOPID
controller to control the above system. Section IV describes
the evaluation of microgrid perfomance using the proposed
controller. Conclusion of the article has been carried out in
Section V.
2. Modelling of Microgrid
Schematic of a single phase islanded microgrid sourced
by a single power generator is expounded in Fig. 1. It is
observed from the Fig. 1 is that the inductor voltage vL is,
vL = L
diL
dt
(1)
Hence,
diL
dt
=
vL
L
(2)
where iL is the inductor current.
Here,
vs = vL + vG (3)
Hence,
vL = vs − vG (4)
From Eq. (2),
diL
dt
=
vs − vG
L
(5)
where vG is the grid voltage and vs is the voltage after
inverted by VSI. The voltage is the multiplication output of
the duty cycle (α) with dc source voltage (vdc).
The laplace transformation of the Eq. (2)
VL(s) = sLiL(s) (6)
Hence,
IL(s) =
VL(s)
sL
=
Vs(s) − VG(s)
sL
(7)
The capacitor voltage which can be termed as the grid
voltage can be accessed as,
dvG
dt
=
1
C
iC (8)
where iC can be termed as the current through capacitor.
The state space representation of a system can be shown as,
dx
dt
= Ax + Bu (9)
and
y = Cx + Du (10)
Where, x = [iL; vG] represents the state vector, A =
[0, −1/L; 1/c, 0] represents the state coefficient matrix, B =
[1/L; 0] represents the control vector, u = vs represents
the input control variable, y = [0 : vG] represents the
output vector, C = [0, 1] represents the output coefficient
vector, D = 0 represents the transient vector. Here, d = iG
represents disturbance that is created as a result of unknown
composition in microgrid system. It is originated during the
turn on or off of the load during the activation period of
microgrid. From equation (9) and (10)it is accessed,
d
dt
iL
vG
=
0 − 1
L
1
C 0
iL
vG
+
iL
0
vs
+
0
− 1
C
iG
and the system output,
y =
vG
=
0 1
iL
vG
The ratings of the components of the microgrid plant are
presented by Table 1.
TABLE 1: Component ratings of microgrid plant
Components Ratings
Source DC voltage (Vdc) 300V
Capacitance (Ct) 15μF
Inductance (Lt) 2mH
Wire Resistance (Rline) 0.45 Ω
Load Resistance (R) 40 Ω
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3. 3. Design of Controller
The devise of PID controller of fractional order using
trial and error method is discussed abruptly in this section.
3.0.1. Fractional Order Controller. Fractional Order Con-
trol (FOC) is an abstraction of the Integer Order Con-
trol(IOC) into the order of fraction. [19]. The Order ab-
straction goes here:
Dα
=
⎧
⎨
⎩
dα
dtα , ifα 0
1, ifα = 0
t
0
dτ−α
, ifα 0
⎫
⎬
⎭
(11)
where α Re is the order of the fractional order system.
The definitions representing fractional order derivative goes
here:
The order of the system is defined by Riemann and Liouville
[20] that generalizes the following definition:
Dα
t f(t) =
dm
dtm
[
1
Γ(m − α)
t
0
f(τ)
(t − τ)(α + 1 − m)
dτ]
(12)
where mZ+
, (m − 1) α ≤ m, α − m − 1 1, Dα
t f(t)
representing the derivative of the function of time f(t) of the
order of α (positive non-integer number) in the limit 0 to t,
1
Γ(m−a) represents the inverse fractional factorial of (m−α)
and τ is a variable in complex plane.
Another definition is proposed by Grunwald and Letnikov
[21] that generalizes the following definition: ,
Dα
f(t) = lim
h→0
1
hα
t−α
h
m=0
(−1)m Γ(α + 1)
m!Γ(α − m + 1)
f(t − mh)
(13)
where, Dα
t f(t) representing the α (positive non-integer
number) order derivative of the function of time f(t) in the
limit 0 to t.
3.0.2. Fractional Order PID Controller. The parallel form
of the fractional PID controller, called the PIλ
Dμ
controller
[22] has the following transfer function:
C(s) = Kp +
Ki
sλ
+ Kdsμ (14)
where Kp, Ki, Kd, λ and μ are the proportional gain, in-
tegral gain, derivative gain, order of the integral component
and order of the derivative component respectively.
The fundamental purpose of the controller design is to
take care of the unwanted fluctuations in the output voltage
of the islanded microgrid. The encouragement is to gain
stable output voltage without fluctuation and robust perfor-
mance while the system undergoes uncertainty. It can be
seen that the fractional order PID controller gives more flexi-
bility in tuning than conventional PID controller because the
conventional PID controller gives three parameters to tune
the controller where the fractional order PID controller gives
five parameters for getting it tuned. The order of the integral
)
(
)
( s
v
s
y G
Plant
G(s)
Controller
C(s)
)
(
)
( s
v
s
u s
-
)LJClosed-loopsystem
and differential components of the PID controller can be set
at a fractional order to have an optimum response from the
system.
Fig. 2 serves as the block diagram of the system with the
proferred controller in closed loop. Where, G(s) represents
transfer function of the microgrid system which is the ratio
of input supply voltage vs(s) to grid output voltage vG(s)
according to the single phase microgrid system in Fig.
1 . C(s) represents the transfer function of the proffered
controller. u(s) represents the reference voltage and y(s)
represents the output from the system.
The closed-loop transfer function of the feedforward
interconnection of the plant G(s) with the controller C(s)
can be obtained as:
Gc(s) =
G(s) ∗ C(s)
1 − G(s) ∗ C(s)
(15)
Parameters of the controller has been selected using trial
and error method. The values are presented in Table 2.
TABLE 2: Parameter values for Fractional Order PID Con-
troller
Parameter Value
Kp 240
Ki 4.8 × 106
Kd
3 × 10−3
λ 1 × 10−2
μ 1.99
4. Evaluation of Performance
Performance of the microgrid under the application of
FOPID is evaluated in this section.
4.1. Step and frequency analysis
Fig. 3(a) represents the analogy of the open-loop step
response with closed-loop step response.It is observed that
oscillation is created in the open-loop response whereas the
closed loop system gives an instant response with low steady
state error. The obtained result ensure the high performance
of the fractional order PID controller. Fig. 3(b) represents
the analogy of the open-loop bode plot with closed-loop
bode plot. Form the figure, it is observed that resonance
frequency 5600 rad/s occurs at 40 dB without controller. In
the closed loop response, the controller is able to 40 dB
damping of voltage fluctuations that establishes a speedy
and snug activity of microgrid.
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4. Plant
G(s)
Controller
C(s)
-
Plant
G(s)
Controller
C(s)
-
Magnitude
(dB)
(a) (b)
(a) (b)
Magnitude
(dB)
(c)
)LJ (a) The addition of Uncertainty into the system, (b) Step response of the analogy of open-loop and closed-loop
system under uncertainty,(c) Bodediagram of the analogy of open-loopand closed-loop system underuncertainty.The
blueline(-)isforrepresentingtheopen-loopresponseandtheredline(- - )isforrepresentingtheclosed-loopresponse.
(a) (b) (c) (d)
)LJSchematicofdifferentloads(a)Unknownload,(b)Dynamicload,(c)Non-linearload,(d)Harmonicload.
4.2. Robustness of FOPID controller
The robustness analysis of FOPID controller is verified
in this section. Fig. 4(a) represents the integration of uncer-
tainty to test the the robustness of FOPID controller. Here,
G(s) represents the microgrid system, Wi(s) and Δi(s) rep-
resent the plant variatons. The value of uncertainty is chosen
as twenty five percent of the amplitude of the reference
signal. The obtained result for uncertainty is presented in
4(b) and 4(c). All of the results for uncertainty confirms the
closedloop system remain stable with high bandwidth and
less time require to reach steady-state value. This perfor-
mance ensures that the proffered controller is robust against
uncertainties.
4.3. Performance against Unknown Load
Fig. 5(a) represents the schematic of an unknown load
that is having a parallel connection with microgrid. Fig. 6(a)
represents the performance of the system under unknown
load conditions with and without getting connected to the
controller. The analogy of the open-loop and closed-loop
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5. (a) (b)
(c) (d)
)LJPerformanceevaluationwithdifferentloads(a)Unknownload,(b)Dynamicload,(c)Non-linearload,(d)Harmonic
load.Thesolidline(-)isforrepresentingtheReferenceSinewave,solidline(-)isforrepresentingtheopen-loopoutput
waveformanddashedline(- - )isforrepresentingtheclosed-loopoutputwaveform.
output voltage show that the closed loop voltage has high
in performance than open-loop voltage.
4.4. Performance against Dynamic Load
A single phase induction motor is taken as a dynamic
load that is shown in Fig. 5(b). Analogy of performance
of open-loop and closed-loop system under dynamic load
is presented in Fig. 6(b) . It is seen that the open-loop
signal oscillates and even if the oscillation is reduced, it
can not track the reference signal. Initially, the closed loop
response also oscillates but it tracks the reference voltage at
0.005 seconds. The comparison ensures that the closed-loop
is better as compared to open-loop system.
4.5. Performance against Nonlinear Load Dynam-
ics
Fig. 5(c) represents the model of a non-linear load which
is a two-phase four-pulse diode-bridge rectifier. Fig. 6(c)
shows the analogy of the open-loop and closed-loop voltage
under the admittance of non-linear load which ensures the
high performance of proffered controller.
4.6. Performance against Harmonic Load
Fig.5(d) represents the schamatic of a load that creates
harmonics. The schematic consists of a resistance connected
in series with a current source having amplitude of 7A
and frequency of 150 Hz. Fig.6(d) shows the result of
investigation. The investigation shows that the open-loop
voltage oscillates and even if the oscillation is reduced,
the response can not track the reference signal. Initially,
the closed voltage also oscillates but it tracks the reference
voltage at 0.0057 seconds.
So,it is observed that the proffered controller provides
balanced, efficient and high accuracy voltages.
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6. 5. Conclusion
In the article, the design of Fractional-Order PID Con-
troller is proffered for a single phase islanded microgrid sys-
tem which runs with a single energy source. The application
of FOPID to the microgrid system makes it spectacle that
the proffered controller certifies a fast, robust and precise
operation of the microgrid system.
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