可有效降低共模电压的矩阵变换器调制方法研究

矩阵变换器以其诸多理想特性受到越来越多的关注.而PWM调制技术的应用不可避免地会产生高频共模电压,对电气设备的运行会产生相当大的危害.分析了矩阵变换器共模电压产生的机理,基于双电压合成策略,提出了一种可有效降低矩阵变换器共模电压最大值的优化方法.该方法通过调整零输出电压组合所对应的输入相电压,可将共模电压的最大值从输入相电压幅值降低为原来的0.577倍,同时保持输出电压和输入电流的局部平均值不受影响.并通过调整开关顺序,使一个开关周期内的换流次数保持8次不变.仿真结果验证了结论的正确性.

Research on Modulation Strategy of Matrix Converter to Reduce Common-mode Voltage

Matrix converter has received considerable attention due to its nearly ideal characteristics.The use of PWM modulation technology will cause highfrequency common-mode voltage inevitably,which would be very dangerous to the electrical equipment.The mechanism of common-mode voltage of matrix converter was analyzed,and based on the two line voltage synthesis strategy, an approach to reduce common-mode voltage at the output of a matrix converter was presented.By changing the input phase of zero-output voltages combination, the method can reduce the peak value of common-mode voltage from 1 to 0.577 times the peak value of input phase voltage,and has no effect on the local averaged value in duty time of output voltage and input current.By rearranging the switching sequence,the number of switch commutations in each cycle period remains 8.The validity of the conclusion is demonstrated by simulation results.