铁磁损耗对直接转矩控制低速性能的影响及补偿方法研究

Study of Compensation Method and Iron Loss Influence on DTC Low-speed Performance

为了探讨铁磁损耗对直接转矩控制(DTC)性能的影响,在两相静止坐标系下建立了考虑铁磁损耗的异步电机动态等效数学模型。基于考虑和不考虑铁磁损耗两种情况对传统DTC控制性能进行了分析比较,结果表明铁磁损耗会造成电机低速时的实际输出转矩减小,电机的动态响应速度变慢。并在基于考虑铁磁损耗的情况下提出一种对铁磁损耗补偿的方法,使传统的估算转矩更接近于实际输出转矩,提高了转矩控制性能。实验结果证明了补偿控制方法的有效性,并能改善DTC系统的低速性能。

In order to study the effect of iron loss to direct torque control performance. The dynamic equivalent mathematical model of inductor motor considering iron loss is established under two-phase static coordinates. And the performance caused by conventional DTC controller between the inductor motor model taking no account of iron loss and the one taking iron loss into account is analyzed eontrastively. It is manifested that the iron loss would caused torque decreasing at low speed and slower speed response of inductor motor direct torque control. Therefore, a kind of eompensator based on dynamic equivalent mathematical model of inductor motor considering iron loss is proposed to make conventional torque estimation be closer to actual output torque, and the performance of torque control is improved too. What＇s more, the validity of proposed compensate method is verified by experiment results. Especially, it can promote the low-speed performance of direct torque control.