阶梯波合成整流器及其闭环控制策略

Rectifier Based on Staircase Synthesize Technique and Its Close-loop Control Strategy

研究一种阶梯波合成整流器,该整流器具有开关频率低、输出电流谐波含量小、滤波器体积小以及输入功率因数和输出直流电压可调节等优点,非常适合大功率应用场合。由于开关频率较低,传统的高频脉宽调制(pulse width modulation,PWM)整流器的闭环设计方法不能用于瞬时值闭环控制器设计,为实现阶梯波合成整流器的瞬时值闭环控制,该文对其进行了详细地数学建模和分析。在系统的带宽范围内,把高阶滤波器等效为一阶电感滤波器,并采用相位补偿措施降低PWM调制环节延时给系统带来的影响。在简化模型的基础上,设计瞬时值反馈闭环控制器。通过参数优化设计,可以获得优良的系统动态响应性能。仿真和试验结果验证该控制器的性能。

A staircase synthesized rectifier was introduced which is suitable for high power applications due to its low switching frequency,low line current harmonics,less volume filter and controllable power factor as well as adjustable output DC voltage. But it＇s hard to design instantaneous feedback close-loop-control with the aid of conventional pulse width modulation （PWM） rectifier＇s close-loop design method because of a much narrow bandwidth. This paper presented the rectifier model in detail,and the characteristics of the model were analyzed. The high order filter was simplified as an L-filter in the system bandwidth and phase compensation was adopted to reduce the negative affect to the rectifier by the PWM modulation delay. Based on these,the instantaneous feedback close-loop control strategy was proposed,and the parameters of the controller were optimized to get high-speed response capability. The results of simulation and experiment are provided to verify the controller＇s performance.