兆瓦级逆变器并联系统中点平衡及环流控制  

Neutral Point Balance and Circulation Control in Parallel System of MW Level Inverter

作　　者：卫楚奇 石磊[1] 周百灵[1] WEI Chu-qi;SHI Lei;ZHOU Bai-ling(State Grid Electric Power Research Institute,Nanjing 211106,China)

机构地区：[1]国网电力科学研究院,江苏南京211106

出　　处：《电力电子技术》2020年第9期30-32,共3页Power Electronics

摘　　要：针对兆瓦级三电平逆变器并联系统,研究一种基于零序电压补偿的无差拍环流控制方法,并研究了改进空间矢量脉宽调制(SVPWM)的策略来保证三电平逆变器中点电压平衡。首先分析了并网逆变器并联系统中零序电流的等价模型,根据零序电流反馈量得到零序电压补偿量,进而抑制零序环流。然后针对三电平逆变器,分析了利用重新分配正负小矢量的作用时间来控制其中点电压平衡的方法。最后,通过仿真和实验验证了该环流抑制方法和中点电压平衡策略的有效性。A deadbeat circulating current control method based on zero sequence voltage compensation is studied for the parallel system of MW level three-level inverter,and an improved space vector pulse width modulation(SVPWM)strategy is proposed to ensure the balance of neutral point voltage of the three-level inverter.Firstly,the equivalent model of zero sequence current in parallel system of grid connected inverter is analyzed.According to the feedback of zero sequence current,the zero sequence voltage compensation is obtained,and then the zero sequence circulating current is suppressed.Then,for the three-level inverter,the method of controlling the middle point voltage balance by redistributing the action time of positive and negative small vectors is analyzed.Finally,the effectiveness of the circulating current suppression method and the neutral point voltage balance strategy is verified by simulation and experiment.

关 键 词：逆变器 零序环流 中点电压平衡 

分 类 号：TM464[电气工程—电器]