双重d-q空间下五相电压源逆变器空间矢量脉宽调制死区效应分析与补偿

Analysis and Compensation of Dead-time Effects in Five-phase Voltage Source Inverters With Space Vector PWM Techniques Based on Dual d-q Space Concept

电压源逆变器(voltage source inverter,VSI)受到死区效应以及开关暂态过程等非线性因素的影响,导致负载电机定子相电流中含有低次谐波,畸变率较大。针对五相VSI系统,在分析其双重d-q子谐波空间及电压矢量空间状态分布的基础上,进行空间矢量脉宽调制算法死区效应的研究。然后,以五相永磁同步电机矢量控制算法为例,根据仿真中设置不同的死区时间得到的电压谐波含量,验证理论分析的正确性,同时对其电流控制方案进行改进,实现双重d-q空间下的谐波电流闭环抑制,从而对VSI系统死区效应进行补偿,达到了消除电机电流中低次谐波的目的。计算机仿真和硬件在环半实物实验结果均验证了该方案的正确性和有效性。

There occurs serious distortion in stator phase currents of multi-phase load motor because of the nonlinear factors caused by dead-zone and switching transition. In this paper, based on dual d-q spaces concept and voltage vectors distribution, dead-time effects in five-phase voltage source inverter （VSI） with space vector pulse width modulation （SVPWM） was discussed and deduced. Then taking field oriented control method as an example, simulation results illustrate the effectiveness of theoretical analysis in various dead times condition. A modified current control scheme was proposed to fully compensate dead-time effect of inverter and provide very perfect sinusoidal currents. Computer simulation and hardware-in-loop （HIL） experimental results show the validity and effectiveness of the proposed dead time compensation scheme.