摘要
虚拟同步发电机(virtual synchronous generator,VSG)可实现分布式电源友好并网。然而,电网电压不平衡时,传统VSG控制会导致三相并网电流不平衡,为此提出一种VSG平衡电流控制方法。首先分析了VSG在电网电压不平衡情况下存在的问题及其与传统逆变器控制的区别;在此基础上,利用VSG在dq坐标系下的特点设计电流指令计算方法,使VSG在各种类型的不平衡电压下实现负序电流抑制。该方法计算逻辑简单,且能够实现不同工况下的自适应控制。仿真和实验结果表明了所提控制方法的正确性和有效性。
Virtual Synchronous Generator（VSG） can make distributed generation friendly connect to power grid. However, when three-phase gridvoltage becomes unbalanced, traditional VSG control will lead to unbalanced three-phase current. To solve this problem, a VSG balanced current control method is proposed. VSG problem caused by unbalanced grid voltage and its distinction from traditional inverter control are demonstrated. Then, a current reference calculation method is designed based on VSG features in d-q coordinate system tosuppress negative-sequence current under different types of unbalanced voltage. Calculation logic of the method is simple, and can realize self-adaptive control under different conditions. Simulation and experiment results verify validity and effectiveness of the proposed method.
出处
《电网技术》
EI
CSCD
北大核心
2016年第3期904-909,共6页
Power System Technology
基金
国家自然科学基金创新研究群体项目(51321005)~~
关键词
虚拟同步发电机
并网控制
不平衡电压
负序电流抑制
virtual synchronous generator
grid-connection control
unbalanced voltage
negative-sequence current suppression
