基于改进下垂法的微电网逆变器并联控制技术  

Parallel Control Technology for Microgrid Inverters Based on Improved Droop Method

作　　者：周奇勋[1,2] 张红 曹世宏 黎文权 曹浩翔 李萌[1] ZHOU Qixun;ZHANG Hong;CAO Shihong;LI Wenquan;CAO Haoxiang;LI Meng(School of Electrical and Control Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;Key Laboratory of Embedded System and Service Computing(Ministry of Education),Tongji University,Shanghai 200092,China;Construction Engineering Research Institute,Xi’an 710054,China)

机构地区：[1]西安科技大学电气与控制工程学院,西安710054 [2]同济大学嵌入式系统与服务计算教育部重点实验室,上海200092 [3]总后勤部建筑工程研究所,西安710054

出　　处：《电力系统及其自动化学报》2018年第8期25-31,共7页Proceedings of the CSU-EPSA

基　　金：国家自然科学基金资助项目(51307137);同济大学嵌入式系统与服务计算教育部重点实验室开放课题基金资助项目(ESSCKF 2016-05);中国博士后基金资助项目(2014M552618);西安科技大学博士(后)启动资金资助项目(2014QDJ082);西安科技大学科研培育基金资助项目(201317)

摘　　要：为实现逆变器并联系统在线路阻抗不同情况下实现功率均分和环流抑制,同时为了提高系统的动态响应,提出了一种改进的逆变器并联下垂控制方法。针对传统下垂法反馈信号不可能准确测到等效线路阻抗后的公共节点电压,采用逆变器输出端电压推导出了改进功率计算公式,提高了微电网逆变器并联均流控制器的控制精度;针对微电网逆变器并联时不同电压等级连接线路阻抗不同引起的无功环流,设计了线路压降补偿环节,改善了逆变器并联系统的均流性能;针对利用低通滤波器计算功率时对并联系统动态响应的影响,在传统下垂法的基础上增加积分环节和微分环节,加快了系统的动态响应,消除了静态误差。仿真结果表明,该改进下垂控制法可以很好地实现逆变器的功率均分和环流抑制,提高了系统响应速度。To realize power-sharing and circulating current suppression of a parallel inverter system with different line impedances while improvingthe dynamic response of the system,an improved parallel inverter droop control method is proposed.Considering that the feedback signal from the conventional droop method cannot accurately measurethe public node voltage of equivalent line impedance,an improved power formula is derived by means of the inverter output voltage,so as to improve the control precision of the parallel current-sharing controller in themicrogrid inverter;as for the reactive circulating currentin the parallel connection of microgrid inverters,which is caused by different connection line impedances at different voltage levels,aline voltage drop compensation link is designed to improve the currentsharing performance of the parallel inverter system;in light of the effect on the dynamic response of the parallel system when using a low-pass filter to calculate power,integral and differential links are added on the basis of the traditional droop method,which accelerates the dynamic response of the system and eliminates static errors.Simulation results show that the improved droop control method can achieve the power-sharing and circulating current suppression for the inverter,and improve the response speed of the system.

关 键 词：微电网 下垂控制 并联 线路阻抗 环流 

分 类 号：TM46[电气工程—电器]