逆变器输出电压模型及新型死区补偿方法

摘要

The influence of dead-time on three-phase voltage source inverter output voltage using SVPWM modulation is analyzed in the paper.In order to reduce the voltage distortion,current harmonics and torque ripple caused by the dead time effects,dead-time compensation is needed.This paper presents the method of estimating current vector angle indirectly by power-factor angle,and gives the relationship between the position of output current vector and the direction of three-phase current.On this basis,the compensated voltage value is calculated.At last,in order to test the performances of this method,experiments are carried out using TMS320F2812 controller.The experimental results proved the validity of the proposed method.%针对电压源型逆变器,建立了逆变器输出电压的数学模型,该模型描述了死区时间、功率器件管压降、开通时间、关断时间和相电流对逆变器输出电压的影响。基于该数学模型提出了一种新型的死区补偿方法。在该补偿方法的实现过程中,需要对电流方向进行精确判断,为此基于空间矢量角的概念,提出了一种新型的利用功率因数角实现的电流方向间接检测方法,该方法能够有效地抑制各种扰动引起的电流方向误判断。最后,利用TMS320F2812DSP控制器对这种死区补偿方法的性能进行了检验,实验结果证明了该方法的有效性。