正弦和空间矢量PWM逆变器死区效应分析与补偿

给出了PWM逆变器死区效应引起的误差电压矢量,采用矢量合成的方法,推导了死区效应作用下电机绕组产生的合成电压矢量的幅值和相位计算公式,结合仿真分析了合成电压矢量的特征。为保证开关管实际开通时间与理想给定开通时间相等,提出了死区的时间补偿方法,结合SVPWM的特点,得到了简化算式。从消除误差电压矢量着手,提出了死区的电压补偿方法,根据SPWM和SVPWM调制方法不同,分别计算出在定子三相静止坐标系和两相静止坐标系内做死区电压补偿的算式。实验结果表明,所提出的补偿方法能使电机相电流波形正弦化,提高了逆变器输出性能。

Dead-time Effects Analysis and Compensation of SPWM and SVPWM Inverter

Error voltage vectors caused by dead-time effects of PWM inverter were given,the vector synthesis method was adapted to educe amplitude and phase formulas of synthesized voltage vector produced by 3-phase stator windings under dead-time effects,the characteristic of synthesized voltage vector was analyzed with simulations.In order to make practical conduct time equal to ideal given time of switching devices,a dead-time compensation method based on time was proposed,simple arithmetic was obtained with the characteristic of space vector PWM(SVPWM).A dead-time compensation method based on voltage was proposed also to eliminate error voltage vector,compensation formulas were calculated in 3-phase and 2-phase static reference frame respectively corresponding to SPWM and SVPWM.Experimental results show that the proposed method can make motor phase current waveform sinusoidal,and improved the output performance of the inverter.