scholarly journals Reactive power sharing among distributed generators in a microgrid by using virtual current

2021 ◽  
Vol 12 (1) ◽  
pp. 99
Author(s):  
Eder A. Molina-Viloria ◽  
John Edwin Candelo Becerra ◽  
Fredy Edimer Hoyos Velasco
Keyword(s):  
Control Strategy ◽  
Power Distribution ◽  
Reactive Power ◽  
Power Sharing ◽  
Current Loop ◽  
Load Variations ◽  
Margin Of Stability ◽  
Distributed Generators ◽  
Current Controller ◽  
Electrical Loads

This paper presents a new autonomous effective power distribution control strategy for three-phase parallel inverters. The proposal uses a controller that can provide the system with accurate power sharing among distributed generators installed in the microgrid once some load variations are presented in the network. The methodology uses a virtual current loop introduced into the current controller of the inverter to optimize the output signal, which goes directly to the PWM. This virtual current is obtained by using a virtual impedance loop. Furthermore, a small-signal model of the system is used to check stability of the proposed control strategy, which was developed for island mode operation of the microgrid. Simulations were performed for a microgrid with two generators and a load with five households and implemented in MATLAB/Simulink software. The results show that the model provides a wide margin of stability and a rapid response when electrical loads change, thus fulfilling the reactive power sharing among generators. The proposed method shows a large margin of stability and a rapid transient response of the system.

scholarly journals Autonomous microgrid based parallel inverters using droop controller for improved power sharing

2020 ◽  
Vol 9 (6) ◽  
pp. 2302-2310
Author(s):  
Siddaraj Siddaraj ◽  
Udaykumar R. Yaragatti ◽  
Nagendrappa H. ◽  
Vikash Kumar Jhunjhunwala
Keyword(s):  
Energy Source ◽  
Reactive Power ◽  
Active Power ◽  
Power Sharing ◽  
Voltage Source ◽  
Voltage Source Inverters ◽  
Distributed Generators ◽  
Current Controller ◽  
Power Frequency

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.

scholarly journals Reactive power sharing in microgrid using virtual voltage

2021 ◽  
Vol 11 (4) ◽  
pp. 2743
Author(s):  
Eder A. Molina-Viloria ◽  
John E. Candelo Becerra ◽  
Fredy E. Hoyos Velasco
Keyword(s):  
Power Control ◽  
Control Strategy ◽  
Reactive Power ◽  
Low Voltage ◽  
Active Power ◽  
Power Sharing ◽  
Droop Control ◽  
Matlab Simulink ◽  
Distributed Generators ◽  
Additional Coefficient

The traditional droop control strategy has been applied previously in microgrids (MGs) to share accurately the active power. However, in some cases the result obtained when sharing reactive power is not the best, because of the parameters related to the distances from distributed generators (DGs) to the loads and the power variations. Therefore, this paper proposes a reactive power control strategy for a low voltage MG, where the unequal impedance related to the distances between generators and loads requires adjustments to work with the conventional frequency and voltage droop methods. Thus, an additional coefficient is calculated from parameters of the network that relate the location of elements. The test is perfomed by simulations in the MATLAB-Simulink software, considering a three-node MG with three DGs and a load that can change power at different periods of time. The results show that it is possible to improve reactive power sharing between the DGs located in the MG according to the load changes simulated and to improve voltages with this method.

scholarly journals An Improved Droop Control Strategy for Reactive Power Sharing in Islanded Microgrid

2015 ◽  
Vol 30 (6) ◽  
pp. 3133-3141 ◽  
Author(s):  
Hua Han ◽  
Yao Liu ◽  
Yao Sun ◽  
Mei Su ◽  
Josep M. Guerrero
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Power Sharing ◽  
Droop Control ◽  
Islanded Microgrid

Reactive power sharing control strategy of multi-inverter based on weak communication

2021 ◽  
Author(s):  
Junfei Han ◽  
Lingyu Sun ◽  
Yuqiang Wang ◽  
Chaoyu Yu ◽  
Pengcheng Wang ◽  
...  
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Power Sharing

A Novel Control Strategy for Three-Phase Four-Wire STATCOM

2012 ◽  
Vol 516-517 ◽  
pp. 1722-1727 ◽  
Author(s):  
Wei Jun Yun ◽  
Gang Yao ◽  
Li Dan Zhou ◽  
Chen Chen ◽  
Jun Min Pan
Keyword(s):  
Control Strategy ◽  
Power Distribution ◽  
Distribution System ◽  
Reactive Power ◽  
Control Method ◽  
Loop Control ◽  
Power Distribution System ◽  
Imbalance Problem ◽  
Three Phase ◽  
Close Loop Control

Nowadays Static Synchronous Compensator (STATCOM) has gradually become one of the representative techniques in the field of dynamic reactive power compensation in the power distribution system. This paper analyzed the topology and the voltage imbalance problem of the up and down capacitors on DC side of the three-phase four-wire STATCOM. In allusion to the imbalance problem of neutral point, a novel control strategy based on the control of zero-sequence current was proposed. By the triple close-loop control strategy, the STATCOM can achieve great control accuracy and dynamic performance. Simulation result proves that the proposed control method is effective.

A Self-Adjusting Droop Control Strategy to Improve Reactive Power Sharing in Islanded Microgrid

2020 ◽  
Vol 11 (3) ◽  
pp. 1624-1635 ◽  
Author(s):  
Dharmendra Kumar Dheer ◽  
Yusuf Gupta ◽  
Suryanarayana Doolla
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Power Sharing ◽  
Droop Control ◽  
Islanded Microgrid

scholarly journals Decentralize power sharing control strategy in islanded microgridsDecentralize power sharing control strategy in islanded microgrids

2020 ◽  
Vol 20 (2) ◽  
pp. 752
Author(s):  
Mubashir Hayat Khan ◽  
Shamsul Aizam Zulkifli ◽  
Erum Pathan ◽  
Elhassan Garba ◽  
Ronald Jackson ◽  
...  
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Pi Controller ◽  
Power Sharing ◽  
Control Technique ◽  
Droop Control ◽  
Low Load ◽  
Islanded Mode ◽  
The Stability ◽  
The Cost

<a name="_Hlk16093850"></a><span>Droop control technique is one of the renowned techniques which does not need any communication connection between Distibuted Generations (DG), hence the cost, as well as the reliability of the microgrid (MG) system can be reduced. MG is operated in two modes as their functionality and structure is concern. These are the grid connected or islanded (stand-alone) mode. DGs operating values may have different ratings of voltage, power and line impedance. The power sharing in these operatng conditions is not shared equally by all DGs connected in the system and also during load changes conditions power sharing accuracy is difficult to achieve. In this paper, a droop power control is used to balance the power sharing in islanded mode. As from the results, the active power sharing is equally shared from all DGs connected in the microgrid system. However, reactive power sharing accuracy always disturbed when there is impedance mismatch among the different DG feeders. The accuracy is done by monitoring the effects when load changes for low load to high load or vice versa. The Proportional Integral (PI) controller has been used to minimize the reactive power errors. At the end, the power droop is capable to share power accurately and results prove the stability and reliability of the proposed technique.</span>

scholarly journals Control Strategy to Regulate Voltage and Share Reactive Power Using Variable Virtual Impedance for a Microgrid

2019 ◽  
Vol 9 (22) ◽  
pp. 4876 ◽  
Author(s):  
Eder Molina ◽  
John E. Candelo-Becerra ◽  
Fredy E. Hoyos
Keyword(s):  
Power Control ◽  
Electric Vehicles ◽  
Control Strategy ◽  
Reactive Power ◽  
Control Variable ◽  
Control Voltage ◽  
Primary Control ◽  
Distributed Generator ◽  
Distributed Generators ◽  
Virtual Impedance

This paper presents a control strategy to regulate voltage and share reactive power from distributed generators in a microgrid when electric vehicles (EVs) are connected and disconnected at different nodes and times. The control strategy considers fixed and variable virtual impedances created in the microgrid (MG) when loads change (EVs are connected or disconnected). Fixed virtual impedance is related to the distance from each house to the power inverter and is used as an input of the primary control. Variable virtual impedance is associated with the distance from each EV to the power inverter and is also used as an input of the primary control. Thus, the control of the inverter seeks to regulate the voltage where the EVs create variations in the network. The results show that the control strategy regulates well the voltage of different nodes, and the reactive power is distributed to renewable generators based on the distance from the loads to the inverters. By considering the fixed and variable virtual impedances in the primary control, voltage can be regulated, assuming various consumptions of EVs in the network. This result is promising for reactive power control and sharing for each distributed generator (DG) in a microgrid where a great number of EVs affect the operation.

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