Research On Vector Control Of Household Inverter Air-conditioner Compressor

The interior permanent magnet synchronous motor (IPMSM) has been widely used in many industrial fields for its high efficiency and good performance, especially in the air-conditioner compressor and gas pipeline compressor drive system. Therefore, the traditional air conditioning system based on asynchronous motor has been gradually replaced by the interior permanent magnet synchronous motor (PMSM) . Due to the limitation of the objective conditions, the IPMSM, being responsible for driving can not install the rotor position sensor. In this paper, the research on the vector control system and the speed sensorless estimation of the IPMSM is carried out.As the core of inverter air-conditioner, the speed control system composed of interior permanent magnet synchronous motor has the characteristics of multiple-input multiple-output, strong coupling, nonlinear and time delay which result in poor regulation on real-time adjustment relying on the simple PID controller and even single intelligent algorithm. Especially when compressor running in low speed region, without covering of air sound produced by high speed, the noise due to the large rotating speed pulsation will become the main interference source to the rest of the users. Therefore, the dynamic response ability of the system, the speed control precision and the intelligent degree of the control system need to be improved. In this paper, the advanced fuzzy immune PID controller is designed. The improved fuzzy immune controller uses immune algorithm to optimize the membership function and control rules in different stages to reduce the computational complexity greatly.At the same time, the weighting factor is introduced to realize the control mode conversion between fuzzy control and fuzzy immune PID control. The improved fuzzy immune PID controller can overcome the shortcoming of the traditional fuzzy immune PID which can only optimize the proportional factor and realize the real-time parallel intelligent optimization of proportional, integral and differential parameters.The effect of IPMSM full speed range sensorless controlled only by one method is not ideal. Therefore, the composite observer strategy is proposed, namely that the combination of high frequency pulse injection method and the extended back EMF method, which has good control effect in low and high speed domain respectively. However, the combination of the two kinds of sensorless technology needs to take the joint effect and the switching problem in different speed range into account. The participation degrees of two sensorless technology are determined by weight coefficient changing in linear style. But the speed estimation error of the method in the vicinity of the speed switching point is large, and the linear selection of the weight function is not conducive to the combination of the two estimation methods. So it's necessary to establish a multi-object optimization. In this paper, the genetic algorithm is applied to realize the real-time optimization of the weight coefficient so that the effect degree of the two sensorless control technologies are allocated reasonably.In order to verify the correctness of this study, the Matlab is used to simulate the full range vector control system of the IPMSM inverter air conditioner compressor. The simulation results show that the improved fuzzy immune PID controller can effectively suppress the speed ripple in low speed region, and improve the steady speed precision and dynamic response performance of the full speed range. Meanwhile the simulation results also indicates that the weight coefficients of rotor position compound observer optimized by genetic algorithm make the IPMSM works in speed conversion area with more smooth growth performance and the full speed control of inverter air-conditioner is realized effectively.