农用伺服电机的新颖在线死区补偿方法

Online Novel Dead-time Compensation Method of Agricultural Servo Motor

对SVPWM伺服系统死区效应及在线死区补偿方法进行了探讨。常用的平均死区时间补偿技术是根据参考电压伏秒面积等于补偿后伏秒面积原则,由于难以准确地得到电流的极性所以可能出现误补偿。该文在分析了死区效应对输出电压电流影响的基础上,提出了一种低成本的死区补偿方法。并通过将相电流进行旋转坐标变换计算电流矢量角,间接判断电流极性准确的求出了电流的过零点,从而得到较好的补偿效果。最后在基于TMS320F2812研发的伺服驱动器上测试软件,结果证明了该方法的正确性,有效地减小了死区时间造成的电流畸变并使零电流箝位现象得到明显改善。

The dead-time effect of SVPWM servo system and online dead-time compensation method was discussed. Common average dead- time compensation is based on the principle that the volt-second area of reference voltage equals to the volt-second area after compensation. It is difficult to obtain accurate polarity of the current, so error compensation may appear. After analyzing the dead zone effect on the output volt- age and current influence, this article proposes a low-cost method of dead-time compensation. And by the phase current rotating coordinate transformation to calculate the current vector angle, indirectly determining the current polarity, it can accurately calculate current zero cross- ings and obtain better compensation effect. Finally, based on TMS320F2812 developed low pressure servo drive test software. It proves the correctness of the method which effectively reduces the dead time caused by the current distortion and zero-current clamping phenomenon has been significantly improved.