矩阵式电力变换器换流策略的改进

Improvement of commutation strategy of matrix converter

分析了双电压合成控制策略和传统四步安全换流策略的特点,以矩阵变换器的可靠换流为目标,提出了基于电压法四步安全换流策略的改进方法,包括设计出新的PWM脉冲发生方式和采用电压法三步安全换流策略.新的PWM脉冲发生方式既满足了双电压合成策略需要发出不规则PWM脉冲的要求,也简化了脉冲发生电路设计,采用电压法三步安全换流策略使得换流时间减少了1/3,改善了输出波形质量,同时提高了换流的可靠性.最后通过实验方法验证了改进后的矩阵变换器换流策略的可靠性与正确性.

Aiming at the safe commutation of matrix converter, analyszed the character of two-line voltage synthesis control strategy and the traditional four-steps safe commutation and presented an advanced commutation method based on input voltage. The method includes a new pulse and a three-steps safe commutation strategy based on the voltage method. The new method of generating PWM can not only generate irregular PWM pulses required by twoline voltage synthesis strategy but also simplify the design of PWM generating circuit. With the three-step safe commutation strategy based on the voltage method, the commutation time can be reduced by one-third and enhance the quality of the output waveform as well as the availability of commutation. Finally, the results of experiment demonstrate the availability and correctness of the advanced commutation strategy of matrix converter.