SVPWM逆变器死区效应补偿方法的研究

针对伺服系统矢量控制系统，提出了一种可以补偿死区误差电压并消除零电流钳位效应的死区补偿方法。在分析了影响死区效应的因素以及等效死区时间的表达式的基础上，采用平均死区时间补偿法，在两相静止轴系中对等效死区时间产生的误差电压进行了补偿。为了提高电流极性检测的准确性，利用旋转轴系中的励磁电流和转矩电流分量经过坐标反变换，判断电流在两相静止轴系所处的扇区来决定需要施加的补偿电压。另外为了更好地消除由于死区时间而产生的零电流钳位效应，将一种消除零电流钳位效应的方法结合到上述补偿方法中。最后通过TMS320F2812 DSP芯片来实现补偿算法，并在11kW伺服电机矢量控制系统中验证了补偿算法的有效性。
ABSTRACT: A dead-time compensation strategy is presented to compensate dead-time error-voltage and eliminate zero-current clamping effect for servo motor vector control system. The factor influencing dead-time effect is analyzed, and expression of equivalent dead time is deduced. Average dead-time compensation technique is adopted to compensate error-voltage at two-phase stationary frame. To improve accuracy of detection of current direction, components of magnetizing current and torque current are transformed into two-phase stationary frame. Therefore compensating voltage vector can be decided according to the sector the current vector is locating. In addition, a kind of zero-current clamping effect eliminating scheme is adopted combining with the above compensation method to improve the compensation performance. The proposed compensation method is performed with TMS320F2812 DSP chip. Experimental results demonstrate the efficiency of the dead-time compensation method in 11kW servo motor vector control system.
关键词：伺服系统，空间矢量PWM，死区效应，零电流钳位，补偿