模糊控制在三相PWM整流器无差拍控制中的应用

Application of Fuzzy Control Theory to Deadbeat Control Scheme in Three-phase Pulse Width Modulation Rectifier

无差拍电流控制为了补偿控制延时,需要对参考电流进行超前预测,由于参考变化的不确定性,单一的预测算法在不同参考变化情况下可能产生较大的电流超调或者相位滞后。本文通过对三种常用预测算法进行比较分析,得出预测参数与电流超调和相位滞后之间的关系,以此提出一种基于模糊控制的预测算法。该算法针对不同的参考电流变化选择合适的预测参数,折衷考虑电流超调和相位滞后的影响,限制电流超调最大值,优化相位滞后。最后,结合TMS320F2812数字信号处理器(digital signal processor,DSP)控制平台在三相电压型脉宽调制(pulse width modulation,PWM)整流器上进行实验,验证了理论分析的正确性。

Usually, the deadbeat control strategy uses a forward predictive algorithm of the reference current to compensate the control delay. Because of the uncertainty of reference variations, single predictive algorithm may cause large current overshoot or phase delay in different reference changes. The paper obtained the relationship among the predictive parameter, the current overshoot and the phase delay after comparing and analyzing three commonly used predictive algorithms. Based on it, a new predictive algorithm was introduced using fuzzy control method. This algorithm chose appropriate predictive parameter according to different reference current changes, which was a tradeoff between current overshoot and phase delay. As a result, the maximum value of current overshoot is constrained and the phase delay is optimized. Finally, an experimental prototype of a three-phase voltage source pulse width modulation （PWM） rectifier controlled by a TMS320F2812 digital signal processor （DSP） was built and tested. Experimental results verified the validity of the proposed approach.