基于双PWM技术的变频调速系统的设计

用PWM整流技术代替传统的二极管整流能改善交流调速系统的功率因数。直接功率控制技术的系统结构和算法简单，对于交流侧电压的不平衡和谐波失真有一定的补偿作用；电机控制采用直接转矩控制技术，该方法把转矩直接作为被控量，并且对电机参数不敏感，不受转子参数的影响，简单易行，在很大程度上克服了矢量控制技术的缺点。通过Matlab＼Simulink仿真，验证了双PWM调速策略可以保证交流调速系统的高功率因数和电机优良的调速性能。

Design of AC Drive System Based on Dual-PWM

Instead of traditional diode rectifier, PWM rectifier is introduced to improve power factor of AC drive system. Due to the simplicity of structure and algorithm for direct power control （DPC）, the compensation for voltage unbalance and harmonic distortion in AC side can be brought, direct torque control （DTC） is used in motor control for that it can directly control the torque, is insensitive to motor＇s parameters with simple operation, is without influence of rotor parameters and overcomes many faults of vector control to a large degree. Via Matlab/Simulink simulation, it shows that the dual-PWM can both guarantee the high power factor of AC drive system and excellent performance of motor speed control.