基于满意优化的三电平PWM整流器瞬时开关频率抑制方法  

Instantaneous Switching Frequency Suppression Method for Three-level PWM Rectifier Based on Satisfactory Optimization

作　　者：谭国俊[1] 曹晓冬[1] 王从刚[1] 李浩[1] 

机构地区：[1]中国矿业大学信息与电气工程学院,江苏省徐州市221116

出　　处：《中国电机工程学报》2014年第24期4057-4067,共11页Proceedings of the CSEE

基　　金：江苏省普通高校研究生科研创新计划项目(CXZZ13_0930)~~

摘　　要：提出一种新型的基于满意优化的三电平脉冲宽度调制(pulse width modulation,PWM)整流器有限控制集模型预测控制(finite control set model predictive control,FCS-MPC)方法,将满意优化思想引入模型预测控制的在线规划中,代替传统方法中的权值函数,避免了复杂的加权系数整定过程。然而受到电力电子系统结构的限制,三电平PWM整流器仅可输出27种可行电压矢量,过多的控制约束被引入后,极易造成系统优化无解。该文采用几何分析法揭示了优化无解现象的产生原理,并论证了其与瞬时开关频率过高问题之间的内在联系。通过约束松弛的方式弱化满意和失控的界限,使低优先级指标可以参与在线规划。仿真和实验结果表明,该方法在保证系统功率、中点电位等多项指标达到期望满意度的前提下,最大限度的降低了开关动作频率,避免了高采样频率造成器件局部过热损坏。与经典矢量控制的对比结果可知,在较低的开关频率下(fs≈300 Hz)所提方法可获得更优异的动、稳态性能。This paper proposed an improved finite control set model predictive control （FCS-MPC） for three-level PWM rectifier. In order to avoid the complex adjusting process of weighting coefficient, the concept of satisfactory optimization was introduced into the online optimization for FCS-MPC. However, considering that a three-level PWM rectifier can only provide 27 practical volLage vectors, it is easy to cause the rolling optimization insoluble if too many constraints are added into the online optimization. Principle of the insoluble phenomenon was analyzed by the geometric method. Meanwhile the inner link between the no solution phenomenon and the high instantaneous switching frequency was also demonstrated. The optimized content at low priority can participate in the online optimization, by relaxing constraints to weaken the boundary between the satisfaction and uncontrollability. Simulation and experimental results show that under the condition of keeping the system power, neutral point voltage and some other optimized content reaching the allowed error, the method tries its best to reduce the switching frequency, avoids the local overheating of power device by the high sampling frequency. Compared with the classical field oriented control （FOC）, the proposed MPC can obtain more excellent dynamic and steady state performance at low switching frequency（ fs=300Hz）.

关 键 词：模型预测 直接功率控制 满意优化 缓冲区间 低开关频率 

分 类 号：TM461[电气工程—电器]