不平衡电网电压下三相并网逆变器的控制策略分析

Analysis of Three-phase Solar Inverter Control Strategy under Unbalanced Grid Voltage

针对不平衡电网电压并网成功率低,逆变器控制能力不足的问题,对不平衡电力数据进行整定,通过设计径向基函数(RBF)自适应控制网络完成电力设备在三相不平衡环境下的配合调节,由PI调节器完成参数调节,进而增加并网成功率;采用模型预测控制(MPC)算法对三相异常数据进行排查,通过对比两种不同环境下并网关系推算最佳并网策略,实现电力设备的安全并网。试验表明,采用的KLH系列逆变器,容量为2 KVA/220 V,用这种方式并网产生的不平衡电压变化为85.8 V,并网成功率为95.2%。

In view of the low success rate of unbalanced grid voltage grid connection and insufficient inverter control capability,this paper processes the unbalanced power data,and completes the power equipment in the third stage by designing a radial basis function(RBF)adaptive control network.The coordination adjustment under the phase imbalance environment is adjusted by the PI regulator to increase the success rate of grid connection.The model predictive control(MPC)algorithm is used to investigate the three-phase abnormal data,and the two different environments are compared.The grid connection relationship calculates the best grid connection strategy to realize the safe grid connection of power equipment.The test shows that the KLH series inverter used in this study has a capacity of 2 KVA/220 V,the unbalanced voltage change generated in the grid connection is 85.8 V,and the grid connection success rate is 95.2%.