基于恒定频率转矩控制器的感应电机直接转矩控制

Direct Torque Control of Induction Motor Based on Constant Frequency Torque Controller

为了解决传统直接转矩控制中开关频率变化大和转矩脉动高的缺点,提出了一种恒定频率转矩控制器(CFTC)。该方法是将转矩误差与两个幅值相同、相位互差180°的三角波比较,取代传统的滞环比较器,并对所提出的控制器进行建模和线性化。仿真结果表明所提出的CFTC能够保持开关频率恒定,并且在低速下动态响应好,控制精确性更高,输出转矩得到有效降低且更加平滑。

The traditional direct torque control（DTC） of induction motor has two disadvantages, variable switching fre- quency and high torque ripple. To solve the above problems, a constant switching torque controller （ CFTC ） was proposed. In order to replace the traditional hysteresis eomparator, the method compared the torque error with two triangular waveforms which were 180°out of phase with each other and had the same amplitude, and the proposed controller was modeled and lin- earized. The simulation results show that the proposed CFTC could keep switching frequency stable and had higher preci- sion and better dynamic response at low speed, and the output torque can be effectively reduced and become more smooth.