Untitled Document
Untitled Document
You may need to enable or update / install Adobe Flash Player Plug-in to display JPE e-Book in your device properly. If you use Google Chrome, please find information here
> Archives > Current Issues
JPE, Vol. 19, No. 1, January 2019
Unbalanced Power Sharing for Islanded Droop-Controlled Microgrids
Yaoqin Jia, Daoyang Li, and Zhen Chen
Area Power Quality and Utility Application
Abstract Studying the control strategy of a microgrid under the load unbalanced state helps to improve the stability of the system. The magnitude of the power fluctuation, which occurs between the power supply and the load, is generated in a microgrid under the load unbalanced state is called negative sequence reactive power Q-. Traditional power distribution methods such as P-f, Q-E droop control can only distribute power with positive sequence current information. However, they have no effect on Q- with negative sequence current information. In this paper, a stationary-frame control method for power sharing and voltage unbalance compensation in islanded microgrids is proposed. This method is based on the proper output impedance control of distributed generation unit (DG unit) interface converters. The control system of a DG unit mainly consists of an active-power-frequency and reactive-power-voltage droop controller, an output impedance controller, and voltage and current controllers. The proposed method allows for the sharing of imbalance current among the DG unit and it can compensate voltage unbalance at the same time. The design approach of the control system is discussed in detail. Simulation and experimental results are presented. These results demonstrate that the proposed method is effective in the compensation of voltage unbalance and the power distribution.
Keyword Distributed generators,Microgrid,Power sharing,Voltage unbalance compensation
Untitled Document