基于数字控制器的高性能变频调速系统被越来越广泛应用于工业生产。该文结合高性能变频调速系统应用中的三个关键技术问题——直流预励磁起动电机,电机参数辨识和无速度传感器矢量控制中的磁链闭环观测,对高性能变频调速离散控制带来的离散时间匹配、信号输入同步、输出信号受开关器件约束限制等离散控制问题进行深入研究,并提出相应离散控制结构改进方法。讨论改进控制结构中抗干扰与信号同步措施,分析计算频率与控制误差的关系等问题。该研究结论在55kW与160kW异步电机变频调速实验中得到验证。
The adjustable speed drives (ASD) system based on the digital system is widely applied in the industrial field.This paper focused on three specific aspects about the discrete control strategy for the ASD system,i.e.,the discrete time matching method,synchronization of the input and limitation of the output.On this basis,three critical techniques applied in the high-performance ASD system for the induction motor,i.e.,DC pre-excitation,parameter identification and flux observer in the sensorless control,were effectively implemented.The improved synchronization and anti-interference solutions were also introduced,and the relationship between the global error and the iteration step was analyed.The experiments on the 55 kW and the 160 kW ASD systems validated the effectiveness of the proposed design methods.