The Experts below are selected from a list of 1389 Experts worldwide ranked by ideXlab platform
Arindam Ghosh - One of the best experts on this subject based on the ideXlab platform.
-
improved control strategy for accurate load power sharing in an Autonomous Microgrid
Iet Generation Transmission & Distribution, 2017Co-Authors: Blessy John, Firuz Zare, Arindam Ghosh, Sumedha RajakarunaAbstract:This study proposes a decentralised droop control method for guaranteeing precise load sharing among distributed resources in an islanded Microgrid. Distributed resources are usually fed through power electronic converters and the switching harmonics produced by them are eliminated by third-order output LCL filters. Output impedance is considered as a major factor for finding exact power-angle droop coefficient in droop design - neglecting this factor can affect the load sharing accuracy. Even though an acceptable active power sharing can be achieved with higher droop gains, increased droop gain may adversely affect the Microgrid stability. Here, a modified angle droop control is proposed such that the dependence on the output inductance on the real power sharing is removed. Thus, the lower droop coefficients are sufficient for droop sharing and the system stability is not endangered. It has been assumed that the Microgrid is converter-dominated, where a proportionalresonant controller has been utilised for converter switching control. This controller has an outer voltage loop and an inner current loop. A harmonic term has been added to the voltage loop to facilitate more accurate reactive power sharing. Simulation studies are conducted using PSCAD/EMTDC to validate the efficacy of the proposed controller.
-
Power sharing control of batteries within Autonomous Microgrids based on their state of charge
2015 Australasian Universities Power Engineering Conference (AUPEC), 2015Co-Authors: Tahoura Hosseinimehr, Farhad Shahnia, Arindam GhoshAbstract:This paper presents a new power sharing approach among parallel battery storage systems within an Autonomous Microgrid. The proposed approach considers the state of charge (SoC) of the batteries to control the ratio of their output powers. To facilitate this, a new SoC-based droop control is proposed. In this method, the ratio of output power for all the batteries is determined as a function of their SoC level. This ratio will be varied over time. In order to make the output power of each storage unit independent from the SoC level of the rest of storage units, a modified droop-based voltage control technique is applied for the other energy resources of the Microgrid. By the help of the modified control system, the output power reduction of batteries is only picked up by the energy resources. The studies and discussions are validated through PSCAD/EMTDC simulation studies.
-
Overload prevention in an Autonomous Microgrid using battery storage units
2014 IEEE PES General Meeting | Conference & Exposition, 2014Co-Authors: Megha Goyal, Arindam Ghosh, Farhad ShahniaAbstract:A new control strategy for smooth transition of a battery storage unit (BSU) is proposed in this paper to prevent overloading in an Autonomous hybrid Microgrid. The BSU is controlled to come online to prevent overloading to the distributed generators (DGs) in the Autonomous Microgrid and to go offline when the load demand is less than the total rating of the DGs in the Microgrid. The Microgrid can contain either inertial DG or non-inertial DGs, which are controlled in a frequency droop. The sensing of switching on and switching off of the BSU depends on the frequency signal, which is developed in the paper. The proposed strategy is validated through PSCAD/EMTDC simulation studies.
-
Different power sharing techniques for converter-interfaced DERs in an Autonomous Microgrid
2014 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC), 2014Co-Authors: Tahoura Hosseinimehr, Farhad Shahnia, Ruwan P.s. Chandrasena, Arindam GhoshAbstract:This paper discusses three different techniques which can be used for power sharing control and adjustment among parallel converter-interfaced distributed energy resources in an Autonomous Microgrid. This ratio is decided by the distribution network tertiary controller and passed by the Microgrid central controller to the primary controllers of each energy resource. In this paper limitations of the first two methods are discussed in detail and the proposed (third) method is designed such that it overcomes the limitations of the other two methods. The studies and discussions are validated for an Autonomous Microgrid under consideration through PSCAD/EMTDC-based simulations studies.
-
Advanced Battery Storage Control for an Autonomous Microgrid
Electric Power Components and Systems, 2013Co-Authors: Ritwik Majumder, Gerard Ledwich, Saikat Chakrabarti, Arindam GhoshAbstract:Abstract A new control method for battery storage to maintain acceptable voltage profile in Autonomous Microgrids is proposed in this article. The proposed battery control ensures that the bus voltages in the Microgrid are maintained during disturbances such as load change, loss of micro-sources, or distributed generations hitting power limit. Unlike the conventional storage control based on local measurements, the proposed method is based on an advanced control technique, where the reference power is determined based on the voltage drop profile at the battery bus. An artificial neural network based controller is used to determine the reference power needed for the battery to hold the Microgrid voltage within regulation limits. The pattern of drop in the local bus voltage during power imbalance is used to train the controller off-line. During normal operation, the battery floats with the local bus voltage without any power injection. The battery is charged or discharged during the transients with a high g...
Firuz Zare - One of the best experts on this subject based on the ideXlab platform.
-
improved control strategy for accurate load power sharing in an Autonomous Microgrid
Iet Generation Transmission & Distribution, 2017Co-Authors: Blessy John, Firuz Zare, Arindam Ghosh, Sumedha RajakarunaAbstract:This study proposes a decentralised droop control method for guaranteeing precise load sharing among distributed resources in an islanded Microgrid. Distributed resources are usually fed through power electronic converters and the switching harmonics produced by them are eliminated by third-order output LCL filters. Output impedance is considered as a major factor for finding exact power-angle droop coefficient in droop design - neglecting this factor can affect the load sharing accuracy. Even though an acceptable active power sharing can be achieved with higher droop gains, increased droop gain may adversely affect the Microgrid stability. Here, a modified angle droop control is proposed such that the dependence on the output inductance on the real power sharing is removed. Thus, the lower droop coefficients are sufficient for droop sharing and the system stability is not endangered. It has been assumed that the Microgrid is converter-dominated, where a proportionalresonant controller has been utilised for converter switching control. This controller has an outer voltage loop and an inner current loop. A harmonic term has been added to the voltage loop to facilitate more accurate reactive power sharing. Simulation studies are conducted using PSCAD/EMTDC to validate the efficacy of the proposed controller.
-
enhancing stability of an Autonomous Microgrid using a gain scheduled angle droop controller with derivative feedback
International Journal of Emerging Electric Power Systems, 2010Co-Authors: Ritwik Majumder, Gerard Ledwich, Arindam Ghosh, Firuz ZareAbstract:This paper discusses the stability of an Autonomous Microgrid in which, load sharing by a gain scheduled angle droop controller with derivative feedback is proposed. It is assumed that all the DGs are connected through Voltage Source Converter (VSC). The VSCs are controlled by state feedback controller to achieve desired voltage and current outputs that are decided by a droop controller. First a load sharing strategy is derived in terms of droop controller gain and converter output inductance, combining angle droop controller and DC load flow analysis. Then state space models of converters with its associated feedback controller are derived to investigate system stability as a function of the droop controller gain and converter output inductance through eigen value analysis. It is shown that with proposed angle droop controllers, where the droop gains are scheduled based on the output power along with derivative feedback it is possible to achieve a higher stability margin with better load sharing. These observations are then verified through simulation studies using PSCAD/EMTDC. It will be shown that the simulation results closely agree with stability behavior predicted by the eigenvalue analysis.
-
Enhancing the stability of an Autonomous Microgrid using DSTATCOM
International Journal of Emerging Electric Power Systems, 2010Co-Authors: Ritwik Majumder, Gerard Ledwich, Arindam Ghosh, Firuz ZareAbstract:This paper proposes a method for enhancing stability of an Autonomous Microgrid with distribution static compensator (DSTATCOM) and power sharing with multiple distributed generators (DG). It is assumed that all the DGs are connected through voltage source converter (VSC) and all connected loads are passive, making the Microgrid totally inertia less. The VSCs are controlled by either state feedback or current feedback mode to achieve desired voltage-current or power outputs, respectively. A modified angle droop is used for DG voltage reference generation. Power sharing ratio of the proposed droop control is established through derivation and verified by simulation results. A DSTATCOM is connected in the Microgrid to provide ride through capability during power imbalance in the Microgrid, thereby enhancing the system stability. This is established through extensive simulation studies using PSCAD.
-
Improvement of stability and load sharing in an Autonomous Microgrid using supplementary droop control loop
IEEE Transactions on Power Systems, 2010Co-Authors: Ritwik Majumder, Rajat Majumder, Balarko Chaudhuri, Gerard Ledwich, Arindam Ghosh, Firuz ZareAbstract:This paper investigates the problem of appropriate load sharing in an Autonomous Microgrid. High gain angle droop control ensures proper load sharing, especially under weak system conditions. However, it has a negative impact on overall stability. Frequency-domain modeling, eigenvalue analysis, and time-domain simulations are used to demonstrate this conflict. A supplementary loop is proposed around a conventional droop control of each DG converter to stabilize the system while using high angle droop gains. Control loops are based on local power measurement and modulation of the d-axis voltage reference of each converter. Coordinated design of supplementary control loops for each DG is formulated as a parameter optimization problem and solved using an evolutionary technique. The supplementary droop control loop is shown to stabilize the system for a range of operating conditions while ensuring satisfactory load sharing.
-
power sharing and stability enhancement of an Autonomous Microgrid with inertial and non inertial dgs with dstatcom
International Conference on Pervasive Services, 2009Co-Authors: Ritwik Majumder, Gerard Ledwich, Arindam Ghosh, Firuz ZareAbstract:This paper proposes a method of enhancing system stability with a distribution static compensator (DSTATCOM) in an Autonomous Microgrid with multiple distributed generators (DG). It is assumed that there are both inertial and non-inertial DGs connected to the Microgrid. The inertial DG can be a synchronous machine of smaller rating while inertia less DGs (solar) are assumed as DC sources. The inertia less DGs are connected through Voltage Source Converter (VSC) to the Microgrid. The VSCs are controlled by either state feedback or current feedback mode to achieve desired voltage-current or power outputs respectively. The power sharing among the DGs is achieved by drooping voltage angle. Once the reference for the output voltage magnitude and angle is calculated from the droop, state feedback controllers are used to track the reference. The angle reference for the synchronous machine is compared with the output voltage angle of the machine and the error is fed to a PI controller. The controller output is used to set the power reference of the synchronous machine. The rate of change in the angle in a synchronous machine is restricted by the machine inertia and to mimic this nature, the rate of change in the VSCs angles are restricted by a derivative feedback in the droop control. The connected distribution static compensator (DSTATCOM) provides ride through capability during power imbalance in the Microgrid, especially when the stored energy of the inertial DG is not sufficient to maintain stability. The inclusion of the DSATCOM in such cases ensures the system stability. The efficacies of the controllers are established through extensive simulation studies using PSCAD.
Ritwik Majumder - One of the best experts on this subject based on the ideXlab platform.
-
Advanced Battery Storage Control for an Autonomous Microgrid
Electric Power Components and Systems, 2013Co-Authors: Ritwik Majumder, Gerard Ledwich, Saikat Chakrabarti, Arindam GhoshAbstract:Abstract A new control method for battery storage to maintain acceptable voltage profile in Autonomous Microgrids is proposed in this article. The proposed battery control ensures that the bus voltages in the Microgrid are maintained during disturbances such as load change, loss of micro-sources, or distributed generations hitting power limit. Unlike the conventional storage control based on local measurements, the proposed method is based on an advanced control technique, where the reference power is determined based on the voltage drop profile at the battery bus. An artificial neural network based controller is used to determine the reference power needed for the battery to hold the Microgrid voltage within regulation limits. The pattern of drop in the local bus voltage during power imbalance is used to train the controller off-line. During normal operation, the battery floats with the local bus voltage without any power injection. The battery is charged or discharged during the transients with a high g...
-
Advanced battery storage control for an Autonomous Microgrid
Science & Engineering Faculty, 2013Co-Authors: Ritwik Majumder, Gerard Ledwich, Saikat Chakrabarti, Arindam GhoshAbstract:A new control method for battery storage to maintain acceptable voltage profile in Autonomous Microgrids is proposed in this article. The proposed battery control ensures that the bus voltages in the Microgrid are maintained during disturbances such as load change, loss of micro-sources, or distributed generations hitting power limit. Unlike the conventional storage control based on local measurements, the proposed method is based on an advanced control technique, where the reference power is determined based on the voltage drop profile at the battery bus. An artificial neural network based controller is used to determine the reference power needed for the battery to hold the Microgrid voltage within regulation limits. The pattern of drop in the local bus voltage during power imbalance is used to train the controller off-line. During normal operation, the battery floats with the local bus voltage without any power injection. The battery is charged or discharged during the transients with a high gain feedback loop. Depending on the rate of voltage fall, it is switched to power control mode to inject the reference power determined by the proposed controller. After a defined time period, the battery power injection is reduced to zero using slow reverse-droop characteristics, ensuring a slow rate of increase in power demand from the other distributed generations. The proposed control method is simulated for various operating conditions in a Microgrid with both inertial and converter interfaced sources. The proposed battery control provides a quick load pick up and smooth load sharing with the other micro-sources in a disturbance. With various disturbances, maximum voltage drop over 8% with conventional energy storage is reduced within 2.5% with the proposed control method.
-
Control of battery storage to improve voltage profile in Autonomous Microgrid
2011 IEEE Power and Energy Society General Meeting, 2011Co-Authors: Ritwik Majumder, Gerard Ledwich, Saikat Chakrabarti, Arindam GhoshAbstract:This paper proposes a new control method for battery storage in an Autonomous Microgrid. The battery output is controlled in such a manner that the bus voltages in the Microgrid system are maintained during disturbances such as load change, loss of micro sources or power limit in the DGs. An artificial neural network (ANN) based controller is used to determine the reference power for the battery to hold the Microgrid voltage within regulation limit. The pattern of drop in local bus voltage during power imbalance is used to train the controller offline. Depending on the rate of voltage fall, it is switched to power control mode to inject the reference power determined by the proposed controller. After a defined time period the battery power injection is reduced to zero using slow reverse droop characteristics ensuring a slow rate of increase in power demand from the other DGs. The proposed control method is tested for various operating conditions in a Microgrid with both inertial and converter interfaced sources.
-
enhancing stability of an Autonomous Microgrid using a gain scheduled angle droop controller with derivative feedback
International Journal of Emerging Electric Power Systems, 2010Co-Authors: Ritwik Majumder, Gerard Ledwich, Arindam Ghosh, Firuz ZareAbstract:This paper discusses the stability of an Autonomous Microgrid in which, load sharing by a gain scheduled angle droop controller with derivative feedback is proposed. It is assumed that all the DGs are connected through Voltage Source Converter (VSC). The VSCs are controlled by state feedback controller to achieve desired voltage and current outputs that are decided by a droop controller. First a load sharing strategy is derived in terms of droop controller gain and converter output inductance, combining angle droop controller and DC load flow analysis. Then state space models of converters with its associated feedback controller are derived to investigate system stability as a function of the droop controller gain and converter output inductance through eigen value analysis. It is shown that with proposed angle droop controllers, where the droop gains are scheduled based on the output power along with derivative feedback it is possible to achieve a higher stability margin with better load sharing. These observations are then verified through simulation studies using PSCAD/EMTDC. It will be shown that the simulation results closely agree with stability behavior predicted by the eigenvalue analysis.
-
Enhancing the stability of an Autonomous Microgrid using DSTATCOM
International Journal of Emerging Electric Power Systems, 2010Co-Authors: Ritwik Majumder, Gerard Ledwich, Arindam Ghosh, Firuz ZareAbstract:This paper proposes a method for enhancing stability of an Autonomous Microgrid with distribution static compensator (DSTATCOM) and power sharing with multiple distributed generators (DG). It is assumed that all the DGs are connected through voltage source converter (VSC) and all connected loads are passive, making the Microgrid totally inertia less. The VSCs are controlled by either state feedback or current feedback mode to achieve desired voltage-current or power outputs, respectively. A modified angle droop is used for DG voltage reference generation. Power sharing ratio of the proposed droop control is established through derivation and verified by simulation results. A DSTATCOM is connected in the Microgrid to provide ride through capability during power imbalance in the Microgrid, thereby enhancing the system stability. This is established through extensive simulation studies using PSCAD.
Yan Qi - One of the best experts on this subject based on the ideXlab platform.
-
a statistical model to determine the capacity of battery supercapacitor hybrid energy storage system in Autonomous Microgrid
International Journal of Electrical Power & Energy Systems, 2014Co-Authors: Yunfei Mu, Yan QiAbstract:Abstract Battery–supercapacitor hybrid energy storage system (BSHS) is a key component for regulating the frequency in Autonomous Microgrid. The lifetime and capacity are two important aspects for the efficient and economic use of BSHS. In this paper, the above two aspects are investigated in detail. Firstly, a new frequency control strategy based on hysteretic loop is developed for BSHS to extend the battery lifetime by avoiding small charge/discharge cycles. Then a capacity statistical model which is composed of statistical analysis, time-domain simulation and a capacity determination algorithm is proposed. Monte Carlo simulation is implemented to the statistical model to obtain the capacity distributions of BSHS. Finally, a benchmark low voltage Microgrid is established as the test system using the commercial software DIgSILENT. Simulation results verify the effectiveness of the hysteretic loop control strategy and the capacity statistical model. The obtained capacity distributions of BSHS are used to determine the optimum capacity according to the needs of operation. The results also show that the hysteretic loop control strategy can reduce the capacity of Battery Energy Storage System (BESS) while increase the capacity of Supercapacitor Storage System (SCSS).
-
Dynamic frequency control of Autonomous Microgrid based on family-friendly controllable loads
2013 IEEE PES Innovative Smart Grid Technologies Conference (ISGT), 2013Co-Authors: Yan Qi, Hongjie Jia, Yunfei MuAbstract:Autonomous Microgrid (AMG) develops fast in recent years due to the capability of supplying power to remote areas and avoiding high investment on transmission facilities. Frequency is a key issue for the stable operation of AMG with a large penetration of intermittent renewable energy resources, such as the wind turbines (WT), photovoltaic generators (PV), etc. The fast development of demand response technology provides a new opportunity for the frequency control of AMG. In this paper, a novel decentralized demand-side control (DDC) strategy for family-friendly controllable refrigerators considering customer comfort levels is proposed to regulate the frequency of AMG in coordination with energy storage system (ESS). The refrigerators under DDC respond to the local frequency signals and dynamically adjust their operation cycles. Meanwhile, a customer participation degree which is proportional to the frequency deviation is introduced to evaluate the customer comforts when participate in the frequency regulation. Finally, a benchmark low voltage AMG is established as the test system to verify the effectiveness of the DDC strategy. Simulation results show that the DDC strategy not only can improve the frequency control effect of AMG effectively, but also can reduce the capacity of ESS to a certain extent.
Gerard Ledwich - One of the best experts on this subject based on the ideXlab platform.
-
Advanced Battery Storage Control for an Autonomous Microgrid
Electric Power Components and Systems, 2013Co-Authors: Ritwik Majumder, Gerard Ledwich, Saikat Chakrabarti, Arindam GhoshAbstract:Abstract A new control method for battery storage to maintain acceptable voltage profile in Autonomous Microgrids is proposed in this article. The proposed battery control ensures that the bus voltages in the Microgrid are maintained during disturbances such as load change, loss of micro-sources, or distributed generations hitting power limit. Unlike the conventional storage control based on local measurements, the proposed method is based on an advanced control technique, where the reference power is determined based on the voltage drop profile at the battery bus. An artificial neural network based controller is used to determine the reference power needed for the battery to hold the Microgrid voltage within regulation limits. The pattern of drop in the local bus voltage during power imbalance is used to train the controller off-line. During normal operation, the battery floats with the local bus voltage without any power injection. The battery is charged or discharged during the transients with a high g...
-
Advanced battery storage control for an Autonomous Microgrid
Science & Engineering Faculty, 2013Co-Authors: Ritwik Majumder, Gerard Ledwich, Saikat Chakrabarti, Arindam GhoshAbstract:A new control method for battery storage to maintain acceptable voltage profile in Autonomous Microgrids is proposed in this article. The proposed battery control ensures that the bus voltages in the Microgrid are maintained during disturbances such as load change, loss of micro-sources, or distributed generations hitting power limit. Unlike the conventional storage control based on local measurements, the proposed method is based on an advanced control technique, where the reference power is determined based on the voltage drop profile at the battery bus. An artificial neural network based controller is used to determine the reference power needed for the battery to hold the Microgrid voltage within regulation limits. The pattern of drop in the local bus voltage during power imbalance is used to train the controller off-line. During normal operation, the battery floats with the local bus voltage without any power injection. The battery is charged or discharged during the transients with a high gain feedback loop. Depending on the rate of voltage fall, it is switched to power control mode to inject the reference power determined by the proposed controller. After a defined time period, the battery power injection is reduced to zero using slow reverse-droop characteristics, ensuring a slow rate of increase in power demand from the other distributed generations. The proposed control method is simulated for various operating conditions in a Microgrid with both inertial and converter interfaced sources. The proposed battery control provides a quick load pick up and smooth load sharing with the other micro-sources in a disturbance. With various disturbances, maximum voltage drop over 8% with conventional energy storage is reduced within 2.5% with the proposed control method.
-
Control of battery storage to improve voltage profile in Autonomous Microgrid
2011 IEEE Power and Energy Society General Meeting, 2011Co-Authors: Ritwik Majumder, Gerard Ledwich, Saikat Chakrabarti, Arindam GhoshAbstract:This paper proposes a new control method for battery storage in an Autonomous Microgrid. The battery output is controlled in such a manner that the bus voltages in the Microgrid system are maintained during disturbances such as load change, loss of micro sources or power limit in the DGs. An artificial neural network (ANN) based controller is used to determine the reference power for the battery to hold the Microgrid voltage within regulation limit. The pattern of drop in local bus voltage during power imbalance is used to train the controller offline. Depending on the rate of voltage fall, it is switched to power control mode to inject the reference power determined by the proposed controller. After a defined time period the battery power injection is reduced to zero using slow reverse droop characteristics ensuring a slow rate of increase in power demand from the other DGs. The proposed control method is tested for various operating conditions in a Microgrid with both inertial and converter interfaced sources.
-
enhancing stability of an Autonomous Microgrid using a gain scheduled angle droop controller with derivative feedback
International Journal of Emerging Electric Power Systems, 2010Co-Authors: Ritwik Majumder, Gerard Ledwich, Arindam Ghosh, Firuz ZareAbstract:This paper discusses the stability of an Autonomous Microgrid in which, load sharing by a gain scheduled angle droop controller with derivative feedback is proposed. It is assumed that all the DGs are connected through Voltage Source Converter (VSC). The VSCs are controlled by state feedback controller to achieve desired voltage and current outputs that are decided by a droop controller. First a load sharing strategy is derived in terms of droop controller gain and converter output inductance, combining angle droop controller and DC load flow analysis. Then state space models of converters with its associated feedback controller are derived to investigate system stability as a function of the droop controller gain and converter output inductance through eigen value analysis. It is shown that with proposed angle droop controllers, where the droop gains are scheduled based on the output power along with derivative feedback it is possible to achieve a higher stability margin with better load sharing. These observations are then verified through simulation studies using PSCAD/EMTDC. It will be shown that the simulation results closely agree with stability behavior predicted by the eigenvalue analysis.
-
Enhancing the stability of an Autonomous Microgrid using DSTATCOM
International Journal of Emerging Electric Power Systems, 2010Co-Authors: Ritwik Majumder, Gerard Ledwich, Arindam Ghosh, Firuz ZareAbstract:This paper proposes a method for enhancing stability of an Autonomous Microgrid with distribution static compensator (DSTATCOM) and power sharing with multiple distributed generators (DG). It is assumed that all the DGs are connected through voltage source converter (VSC) and all connected loads are passive, making the Microgrid totally inertia less. The VSCs are controlled by either state feedback or current feedback mode to achieve desired voltage-current or power outputs, respectively. A modified angle droop is used for DG voltage reference generation. Power sharing ratio of the proposed droop control is established through derivation and verified by simulation results. A DSTATCOM is connected in the Microgrid to provide ride through capability during power imbalance in the Microgrid, thereby enhancing the system stability. This is established through extensive simulation studies using PSCAD.
