光伏发电系统输出功率突变引发的逆变器端部过电压机理研究

Research on Overvoltage Mechanism of Photovoltaic Power Generation System Caused by Output Power Changed

光伏发电系统输出功率突变会导致逆变器端部瞬间过电压,造成逆变器内部滤波元件过压损坏,危及光伏发电装备的运行安全。目前,关于此类过压问题的机理不清,相关研究鲜有报道。该文针对光伏发电系统输出功率突变导致的逆变器端部过电压问题,建立包含控制器的逆变器端电压分析模型,揭示由控制器快速响应与端口LC滤波器相互作用而激发的逆变器端部欠阻尼振荡引起的端部过电压机理。基于PSCAD仿真平台和实验平台搭建光伏逆变器联网系统,仿真和实验结果验证所建立模型和理论分析的正确性及有效性。

A sudden change in the output power of photovoltaic （PV） power generation system can cause transient overvoltage at the end of inverter. The overvoltage will cause the internal filter components of the inverter damaged and endanger the operational safety of the power generation equipment for PV. At present, the mechanism of this kind of overvoltage problem is unclear, and related research has rarely been reported. In this paper, an inverter terminal voltage analysis model which contains controller was established for the overvoltage caused by the output power sudden changed of the PV power system. The terminal overvoltage mechanism caused by underdamped oscillation which is the result of the interaction of rapid response of the controller and the LC filter. Based on PSCAD simulation software and experimental platform, a PV power generation system was set up. Simulation and experimental results verify the correctness of the established model and theoretical analysis method.