基于改进模糊免疫PID的变频空调低速域控制研究

Research on the Speed Control Based on Improved Fuzzy Immune PID for Inverter Air-Conditioner in Low Speed Domain

针对家用变频空调压缩机工作于低速域时其转速波动大的问题,以内埋式永磁同步电机(IPMSM)的最大转矩电流比控制系统为平台,设计了改进的模糊免疫PID智能转速控制器。优化的转速控制器利用免疫算法对隶属函数和控制规则进行分阶段优化,大大降低了计算复杂度;同时,引入加权因子,实现了控制器在模糊控制和模糊免疫PID控制之间的控制模式转换。改进的模糊免疫PID控制器克服了传统模糊免疫PID只针对比例系数进行免疫优化的缺点,可实现比例、积分、微分参数的免疫智能实时并行优化。为验证改进控制器的有效性,以MATLAB为平台,以纯滞后系统为控制对象,对改进后和传统的模糊免疫PID控制器的单位阶跃响应控制效果进行对比。对比结果表明前者具有更高的控制精度和更短的上升时间。利用改进的模糊免疫PID代替控制系统中传统的转速控制器,可使压缩机低速域的响应速度和稳态精度得到明显改善。

Considering the problem of high fluctuation of speed of the compressor in inverter air conditioner running in low speed domain,the improved fuzzy immune PID intelligent speed controller is designed with the maximum torque current ratio control system of interior permanent magnet synchronous motor（ IPMSM） as the platform.The optimized speed controller uses immune algorithm to carry out staged optimization for membership function and control rules,thus the complexity of calculation can be greatly reduced.In addition,the weighting factor is introduced to realize the control mode transformation between fuzzy control and fuzzy immune PID control.The improved fuzzy immune PID controller will overcome the shortcomings of traditional fuzzy immune PID which only optimizes the proportional coefficient; it can realize the real-time optimization of the immune system with proportional,integral and differential parameters.In order to verify the effectiveness of the improved controller,with MATLAB as the platform and the dead time system as the control object,the control effects of improved and traditional fuzzy immune PID controllers for step response are compared,the result shows that the improved controller has higher control precision and less rise time.By adopting the improved fuzzy immune PID controller to replace the traditional speed controller in control system,the response speed of the compressor in low speed domain and the steady state accuracy are obviously improved.