Effective Communication-Based Reactive Power Sharing Scheme for Meshed Microgrid in an Islanded Mode

2021 ◽  
Author(s):  
Anitha Daniel ◽  
Suchitra Dayalan
Keyword(s):  
Power System ◽  
Reactive Power ◽  
Local Area ◽  
Power Sharing ◽  
Matlab Simulation ◽  
Distributed Generators ◽  
Control Scheme ◽  
Islanded Mode ◽  
Radial Network ◽  
Virtual Impedance

Microgrids (MGs) are the most sought out and feasible solution for the present energy crisis. MG is a group of Distributed Generators (DGs) interacting with each other to provide energy to a defined local area. The inclusion of DGs into the conventional power system at various voltage levels has altered the topology of the power system and their control techniques. Hence, the MGs can no longer be considered as a traditional radial network but rather a meshed network. The control and operation of such practical MGs become a challenge, especially when operated in the islanded mode. This research paper considers a realistic meshed MG operating in an islanded mode for study. In an islanded MG, the issues of real and reactive power sharing among DGs are addressed so that the power contribution of each DG is proportional to its rating, thus preventing overload and ensuring reliable operation. A communication-based virtual impedance estimation is proposed in addition to the droop controller for proportionate real and reactive power sharing among DGs in a meshed MG. With the increased complexity of meshed MG, the proposed communication-based control scheme offers an efficient reactive power sharing between DGs without the feeder and network impedance requirements. A MATLAB simulation study proves the effectiveness of the proposed control strategy for a meshed MG with equal DG ratings and unequal DG ratings under changing load conditions.

scholarly journals The new power sharing method for threephase parallel inverters with nonlinear loads

2015 ◽  
Vol 18 (1) ◽  
pp. 16-28
Author(s):  
Phuong Minh Le ◽  
Dai Tan Le ◽  
Hoa Thi Xuan Pham
Keyword(s):  
Reactive Power ◽  
Energy System ◽  
Active Power ◽  
Power Sharing ◽  
Control Loop ◽  
Output Impedance ◽  
Nonlinear Loads ◽  
Control Scheme ◽  
Virtual Impedance

This paper presents a new method for controling parallel inverters to share active power and reactive power in the energy system with non-linear loads. In these systems, the virtual output impedance is usually added to the control loop of each inverter to improve the active power and reactive power sharing as well as the quality of the voltage system. Paper also proposes a kind of virtual impedance as a second-order general-integrator (SOGI) scheme. The simulation results in Matlab Simulink show the ability of the proposed controller to good share power P-Q, when connected with unbalanced and nonlinear loads. By using the proposed algorithm allows to reduce the voltage THD to 1.9% and 1.2% for unbalanced and nonlinear loads according by comparision with traditional control scheme.

scholarly journals Multiloop low bandwidth communication-based power sharing control for microgrids

2020 ◽  
Vol 21 (2) ◽  
pp. 682
Author(s):  
Erum Pathan ◽  
Afarulrazi Abu Bakar ◽  
Mubashir Hayat Khan ◽  
Muhammad Asad ◽  
Haider Arshad
Keyword(s):  
Reactive Power ◽  
Power Sharing ◽  
Control Technique ◽  
Voltage Source ◽  
Computational Burden ◽  
Voltage Source Inverters ◽  
Control Techniques ◽  
Equivalent Impedance ◽  
Control Scheme ◽  
Virtual Impedance

<span>In parallel-connected inverter-based microgrids, the reactive power sharing accuracy can not have satisfactory results effortlessly. Mismatch in feeder impedances of the parallel-connected inverter-based microgrids is a significant cause of inaccurate reactive power-sharing. In voltage source inverters (VSI) based microgrids, especially for the islanded mode of operation, the conventional centralized or decentralized control techniques are not much helpful to control the voltage deviations due to impedance mismatch. Mismatch of the feeder impedance is compensated by the addition of fixed virtual impedance. Whereas, the change in the virtual impedance is compensated by adaptive virtual impedance-based control techniques which are helpful to mitigate power-sharing errors, but in most of the control schemes virtual impedance-based control mechanism needs pre-knowledge of feeder impedance which increases the computational burden. This paper presents a decentralized virtual impedance-based power sharing control. In the proposed control solution to mitigate reactive power sharing errors in distributed generation (DG) units, mismatch of the parallel-connected feeder impedance is equalized by regulating the addition of equivalent impedance to each DG inverter. Proposed control technique offers an independent implementation without any pre-knowledge of the feeder impedance. Hence, the implementation of the control scheme is a straightforward and computational burden is also reduced. Simulation results show the effectiveness of the control scheme. </span>

An Islanding Microgrid Power Sharing Approach Using Enhanced Virtual Impedance Control Scheme

2013 ◽  
Vol 28 (11) ◽  
pp. 5272-5282 ◽  
Author(s):  
Jinwei He ◽  
Yun Wei Li ◽  
Josep M. Guerrero ◽  
Frede Blaabjerg ◽  
Juan C. Vasquez
Keyword(s):  
Impedance Control ◽  
Power Sharing ◽  
Control Scheme ◽  
Virtual Impedance

scholarly journals Consensus Control for Reactive Power Sharing Using an Adaptive Virtual Impedance Approach

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2026 ◽  
Author(s):  
Ahmed S. Alsafran ◽  
Malcolm W. Daniels
Keyword(s):  
Rate Of Convergence ◽  
Reactive Power ◽  
Impedance Control ◽  
Power Sharing ◽  
Control Methods ◽  
Triangle Mesh ◽  
Secondary Control ◽  
Consensus Control ◽  
Communication Topology ◽  
Virtual Impedance

Reactive power sharing among distributed generators (DGs) in islanded microgrids (MGs) presents control challenges, particularly in the mismatched feeder line condition. Improved droop control methods independently struggle to resolve this issue and centralized secondary control methods exhibit a high risk of collapse for the entire MG system under any failure in the central control. Distributed secondary control methods have been recently proposed to mitigate the reactive power error evident in the presence of mismatched feeder lines. This paper details a mathematical model of an adaptive virtual impedance control that is based on both leaderless and leader-followers consensus controls with a novel triangle mesh communication topology to ensure accurate active and reactive power sharing. The approach balances an enhanced rate of convergence with the anticipated implementation cost. A MATLAB/Simulink model with six DG units validates the proposed control performance under three different communication structures: namely, ring, complete, and triangle mesh topologies. The results suggest that leaderless consensus control is a reliable option with large DG systems, while the leader-followers consensus control is suitable for the small systems. The triangle mesh communication topology provides a compromise approach balancing the rate of convergence and the expected cost. The extensibility and scalability are advantages of this topology over the alternate ring and complete topologies.

scholarly journals Modeling of Multiple Master–Slave Control under Island Microgrid and Stability Analysis Based on Control Parameter Configuration

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2223 ◽  
Author(s):  
Haifeng Liang ◽  
Yue Dong ◽  
Yuxi Huang ◽  
Can Zheng ◽  
Peng Li
Keyword(s):  
Reactive Power ◽  
Control Method ◽  
Mutual Influence ◽  
Renewable Energy Sources ◽  
System Stability ◽  
Voltage Source ◽  
Stable Operation ◽  
Parameter Configuration ◽  
Islanded Mode ◽  
Virtual Impedance

The stable operation of a microgrid is crucial to the integration of renewable energy sources. However, with the expansion of scale in electronic devices applied in the microgrid, the interaction between voltage source converters poses a great threat to system stability. In this paper, the model of a three-source microgrid with a multi master–slave control method in islanded mode is built first of all. Two sources out of three use droop control as the main control source, and another is a subordinate one with constant power control which is also known as real and reactive power (PQ) control. Then, the small signal decoupling control model and its stability discriminant equation are established combined with “virtual impedance”. To delve deeper into the interaction between converters, mutual influence of paralleled converters of two main control micro sources and their effect on system stability is explored from the perspective of control parameters. Finally, simulation and analysis are launched and the study serves as a reference for parameter setting of converters in a microgrid.

Sign in / Sign up

Export Citation Format

Share Document