采用势函数法的微电网无功控制策略  

Reactive Power Control Strategy of Microgird Using Potential Function Method

作　　者：金鹏[1] 艾欣[1] 王永刚[1] 

机构地区：[1]华北电力大学电气与电子工程学院,北京市昌平区102206

出　　处：《中国电机工程学报》2012年第25期44-51,9,共8页Proceedings of the CSEE

基　　金：国家重点基础研究发展计划项目(973计划)(2009CB219706)~~

摘　　要：由于受到微电网线路阻抗特性等因素的影响,传统的下垂控制存在无功出力难以按照下垂增益分配的问题。分析分布式电源无功出力与空载输出电压之间的关系,并在此基础上提出基于二级控制的微电网无功控制策略。该方案利用无功出力分配关系和空载输出电压的偏离程度构造势函数。微电网中央控制器根据势函数对各分布式电源的空载输出电压进行集中调整,达到改善无功出力分配的目的。仿真结果表明该方案具有良好的动态响应特性和稳态性能。此外,用正则环流无功概念来考察不同负荷水平对分布式电源无功出力分配的影响,进一步验证了所提方案的有效性。Due to the property of line impedance and other factors in microgrid, reactive power supplied by distributed generation units could not be shared in accordance with their voltage droop gains. This paper presented a reactive control strategy of microgird based on secondary control by analyzing the relationship between reactive power and output voltage at no-load. Potential functions which have the objective of reactive power sharing and deviation of output voltage at no-load were established in the proposed method. Microgrid central controller centrally regulated output voltage at no-load of distributed generation units via potential functions, and reactive power sharing among distributed generation units was effectively improved. Perfect dynamic response and steady performances of the proposed scheme were validated by simulation results. In addition, circulating normalised reactive power was introduced to study reactive power sharing among distributed generation units under different load levels, and the validity of the proposed method was further verified.

关 键 词：微电网 分布式电源 下垂控制 无功出力分配 势函数 二级控制 

分 类 号：TM76[电气工程—电力系统及自动化]