无死区模糊准PR控制算法在变频恒流源中的应用

Fuzzy non-ideal proportional-resonant controller with no dead time strategy for variable frequency constant current power supply

针对变压器振动频响法所进行的变频恒流试验的需要,提出了无死区的模糊准PR控制的变频恒流源的设计.利用准PR控制,跟踪给定的参考电流信号,实现了稳定电流输出的同时消除了PID等控制所存在的静差误差问题;设计了无死区策略,消除因为设置死区时间而引起的谐波含量过大的问题;同时引入模糊控制算法,结合准PR控制,实现初始电流的快速跟踪,提高系统的动态响应时间及可靠性.仿真结果表明,在感性负载情况下,该系统可以实现对正弦电流参考的无静差跟踪,并具有谐波分量小和动态响应快等优点.该变频恒流源所提供的电流输出可满足变压器变频恒流试验的要求.

In order to satisfy the need of variable frequency constant current experiment for transformer vibration frequency response analysis, a variable frequency constant current power supply u- sing fuzzy non-ideal PR （proportional-resonant） controller with no dead time strategy is designed. Using the non-ideal PR controller makes the current tracking AC（ alternating current） reference without error in magnitude and angle which exists in the PID （proportion integration differentiation） controller; The excessive harmonics problems caused by dead time are eliminated by designing the no dead time strategy; The fuzzy controller is used to shorten the dynamic response time of the power supply and improve its reliability, and makes the current tracing reference fast in the first period. The simulation results show that in the case of inductive load, the power supply using all these methods has the advantage of no static error in tracing AC reference, small harmonic components, fast dynamic response, etc. As a result the power supply can provide a good current output to meet the requirements of variable frequency constant current experiment.