基于Buck-Boost电路的三电平逆变器

在研究三电平逆变器时，由于直流侧存在中点电压偏移，导致逆变器交流侧输出波形产生畸变，使逆变器不能满足运行状态要求。为此本文针对二极管箝位式三电平逆变器中点电压不平衡问题，详细分析了三电平逆变器产生中点电压不平衡的原因。并在前人研究的于Buck-Boost电路平衡方法基础上，提出了一种基于该方法的中点电压平衡控制策略，并基于Matlab/Simulink仿真平台对本文提出的平衡控制策略进行了仿真研究，仿真结果表明本文提出的平衡控制策略可有效抑制二极管箝位式三电平并网逆变器中点电压不平衡，且在一些条件下效果比小矢量平衡方法要好。

Study on Control Technology of Neutral-Point-Voltage Balance for Three Level Inverter

In the study of three level inverter, due to the unbalance of neutral-point-voltage, resulting in the output waveform distortion, which made the inverter can not meet the operational requirements. For this, the diode clamped three level inverter causes neutral-point-voltage unbalance is analyzed in this paper, and a control strategy based on the Buck-Boost balance circuit is presented, which is verified by Matlab/Simulink. The simulation results show that the control strategy presented in this paper for the Buck-Boost balance circuit, can effectively suppress the unbalance of neutral-point-voltage, and the effect of conditions in some way better than small vector adjustment by SVPWM.