An Improved Droop Control Strategy for Low-Voltage Microgrids Based on Distributed Secondary Power Optimization Control

作     者：Li, Demin Zhao, Bo Wu, Zaijun Zhang, Xuesong Zhang, Leiqi 

作者机构：Southeast Univ Sch Elect Engn Nanjing 210096 Jiangsu Peoples R China State Grid Zhejiang Elect Power Res Inst Hangzhou 310014 Zhejiang Peoples R China 

出 版 物：《ENERGIES》 (能源)

年 卷 期：2017年第10卷第9期

页      面：1347页

核心收录：

学科分类：0820[工学-石油与天然气工程] 08[工学] 0807[工学-动力工程及工程热物理] 

基　　金：National High Technology Research and Development Program of China [2015AA050104] Key R&R Program of Jiangsu province [BE2015012-1] 

主　　题：low-voltage microgrids improved droop control distributed secondary power optimization control consensus algorithm accurate reactive power sharing 

摘      要：To achieve accurate reactive power sharing and voltage frequency and amplitude restoration in low-voltage microgrids, a control strategy combining an improved droop control with distributed secondary power optimization control is proposed. The active and reactive power that each distributed generator (DG) shares is calculated by extracting load information and utilizing a power sharing ratio, and is reset to be the nominal power to recalculate droop gains. The droop control curves are reconstructed according to the nominal active and reactive power and the recalculated droop gains. The reconstructed active power-frequency droop control can regulate active power adaptively and keep frequency at a nominal value. Meanwhile, the reconstructed reactive power voltage droop control can reduce voltage amplitude deviation to a certain extent. A distributed secondary power optimization control is added to the reconstructed reactive power voltage droop control by using average system voltage. The average system voltage is obtained by using a consensus algorithm in a distributed, sparse communication network which is constituted by all controllers of DGs. As a result, accurate reactive power sharing is realized, average system voltage is kept at a nominal value, and all voltage amplitude deviations are further reduced. Due to the absence of a microgrid central controller, the reliability of the strategy is enhanced. Finally, the simulation results validate the proposed method.