一种新颖的空间电压矢量调制逆变器的死区补偿方法

Novel Dead-Time Compensation Strategy for Space Voltage Vector PWM Inverter

介绍了用于三相逆变器的空间矢量调制 (Space vector pulse width modulation,SVPWM)的基本原理。为防止逆变器的桥臂发生“直通”,必须设置“死区”时间。在分析死区效应对空间电压矢量调制输出电压影响的基础上 ,提出死区电压矢量的概念 ,给出死区电压矢量的求取方法。在一个控制周期中 ,可以预先求出几个死区电压矢量的合成作用矢量 ,对参考空间电压矢量进行校正 ,达到消除死区效应的目的。该方法简单 ,不需附加硬件 ,只需要对原控制软件修改即可实现。实验结果表明 。

The space vector pulse width modulation (SVPWM) strategy has characteristics of easy digital realization, it is widely used in inverter. The 'dead time' must be set to prevent the two power switches in the same leg of the inverter shorting directly. The dead time effect will decrease the performance of the inverter if the dead time is considerable comparing with the on time of the power switches, and so the compensation is needed. By analyzing the basic influence of the 'dead time effect' acting on the output voltage of SVPWM inverter, the concept of the dead time voltage vector is put forward. The method for evaluating the dead time voltage vector is deduced. By using the method, the reference voltage space vector of the SVPWM strategy can be modified for eliminating the dead time effect. The method is simple and doesn′t need any additional hardware. It can be realized by modifying the control software. Experimental result proves that it is effective.