电压暂降时并网逆变器电流的VSG抑制技术研究

虚拟同步发电机(Virtual Synchronous Generator,VSG)控制技术能提升分布式电源对电网友好性。然而,电网电压暂降时,传统VSG控制会导致逆变器输出的电流过大,为此提出了一种VSG电流抑制控制方法。文章对电网电压暂降情况的检测进行分析与改进;在此基础上,利用VSG生成的指令电压进行参考电流计算,使VSG在各种电压暂降的情况下能实现对逆变器输出电流的幅值抑制。该方法结构简单,能实现不同故障情况下的电流控制。仿真结果验证了所提控制方法的正确性与有效性。

Research on VSG suppression technology of grid-connected inverter current under Grid Voltage Sag

Virtual synchronous generator(VSG)control technology can improve the grid-friendliness of distributed power supplies.However,the traditional VSG control will cause the current output of the inverter to be too large when the grid voltage drops.Therefore,a VSG current suppression control method is proposed in this paper.Firstly,the detection and improvement of the voltage sag of the power grid are analyzed and improved.On this basis,the reference voltage calculated by the VSG is used to calculate the reference current,so that the VSG can realize the output current amplitude suppression of the inverter under various voltage sag conditions.The method has a simple structure and can realize current control under different fault conditions.The simulation results verify the correctness and effectiveness of the proposed control method.