三相光伏并网逆变器开关损耗抑制策略

Switching Losses Suppression Method for Three-phase PV Grid-connected Inverter

针对并网接口逆变器输出电流需要快速动态响应的运行特点,采用电流滞环控制方法控制逆变器并网,滞环调制采用瞬时值比较方式,它具有自动峰值限制能力、电流跟踪精度高、动态响应快、不依赖负载参数和无条件稳定等优点。针对电流滞环控制开关频率高的缺点,提出一种基于低开关损耗的新型滞环控制方法,对三相并网逆变器进行控制并网,对其工作原理进行了详细分析。与传统滞环控制法相比,在保证并网电流质量的同时大大减小平均开关频率,从而减少了开关损耗。理论分析和仿真结果验证了此方法的正确性、有效性。

Parallel interface inverter output current needs operation characteristics of fast dynamic response, so the hysteresis current control method is adopted to control the inverter grid,which uses comparative instantaneous way.h has the ability to limit the peak automatically, high current tracking accuracy,fast dynamic response, independent of the load parameters and unconditionally stable.For the drawbacks of the high frequency of hysteresis current control switch, a new type of hysteresis control method bases on low switching losses is proposed, three-phase grid-connected inverter control grid is done,and its working principle is analysed.Compared with traditional hysteresis control meth- ods, while ensuring the quality of the grid current,the average switching frequency and the swithing losses are re- duced.Theoretical analysis and simulation results verify the correctness and effectiveness of this method.