面向多逆变器的微电网电压控制策略

针对微电网孤岛运行时有功和无功分量严重耦合引起的无功功率无法精确分配和增加虚拟电抗带来的电压跌落问题,在虚拟同步发电机(virtual synchronous generator,VSG)一次电压控制器的基础上,提出一种在线计算电压控制器参考输入电压的新算法,根据调度有功和无功功率预先估算感应电动势,补偿VSG固有下垂特性和线路阻抗的电压跌落,保证VSG按照设定的U-Q下垂特性运行;设计二次电压控制,用以解决上层调度的周期性、负荷波动的随机性及一次电压控制的有差性等带来的电压质量问题;最后,在Matlab/Simulink仿真平台上验证了所提方案的效果。

Voltage Control Strategies for Microgrid With Multiple Inverters

For dealing with inaccurate distribution of reactive power caused by sever coupling between active and reactive component and voltage droop by adding virtual reactance to inverter during islanded operation of microgrid,a new online estimation of reference voltage for the first voltage controller of virtual synchronous generator(VSG) was proposed.An anticipant electromotive force(EMF) was estimated in advance according to the dispatched active and reactive power.This method would ensure VSG operating in the designed U-Q droop by compensating the voltage droop of inherent droop feature of VSG and line impedance;The second voltage controller was designed to solve the problem of voltage quality caused by dispatching periodicity in the microgrid central controller,the randomicity of load disturbance,the discrepancy of first voltage control and so on.Finally,the proposed scheme is testified on the Matlab/Simulink platform.