多电平三相电压源逆变器结构优化设计

Structural Optimization Design of Multi-level Three-phase Voltage Source Inverter

目前多电平三相电压源逆变器被广泛应用于高压、大功率电子设备中,为解决传统三相电压源逆变器运行中出现的直流侧电容电压失衡问题,基于空间矢量调制开关直流电源对逆变器结构进行优化设计。建立多电平三相电压源逆变器等效模型,利用60°坐标的空间矢量调制算法实现空间矢量调制,利用电容电压平衡算法充分考虑不同矢量间的切换顺序,实现电容电流平衡。实验结果表明,对比传统方法,该方法调制多电平三相电压源逆变器输出线电压波形畸变率为0.18%,电容点电压波动可控制在3 V以内,优于对比方法,具有更好的应用性能。

At present,multi-level three-phase voltage source inverters are widely applied in high-voltage and high-power electronic equipment.To solve the problem of DC-side capacitor voltage imbalance during the operation of the traditional three-phase voltage source inverter,the inverter structure is optimized in this paper based on the space vector modulation switch DC power supply.The equivalent model of a multi-level three-phase voltage source inverter is established,the space vector modulation algorithm of the 60°coordinate is used to realize the space vector modulation,and the capacitor voltage balance algorithm is used to fully take into account the switching sequence between different vectors,thus realizing the capacitor current balance.Experimental results show that compared with the traditional method,the proposed method can modulate the multi-level three-phase voltage source inverter,the output line voltage waveform distortion rate is 0.18%,and the voltage fluctuation at the capacitor point can be controlled within 3 V,indicating that this method is superior to the comparison method and has a better application performance.