Abstract: Aiming at the requirement of axial gas separation force balance between dynamic and static scroll discs of scroll compressor, the variation law of axial gas separation force of scroll compressor was studied, and the scheme of dynamic force balance using electromagnetic method was put forward.The lag phenomena and corresponding causes in dynamic tracking control of electromagnetic force with iron core were analyzed.After the summarizing of traditional PID controls and the traditional control methodsfor lagging system, the dynamic electromagnetic force control method with advance tracking PID was discussed.The control block diagram was firstly given out, and then its stability was analyzed, the time domain implementation method was also deduced.The influence of different parameters on the control performance was analyzed, after which an adaptive advance tracking PID algorithm was presented to find the optimal number of tracking steps in advance. The experimental platform of electromagnetic mechanism and control system was built, and the control method was verified by experiments. The results show that the dynamic electromagnetic force control method based on the adaptive advance tracking PID algorithm can better track the target curve dynamically. The optimal number of advance steps required varies with frequency, and the optimal steps of advance tracking required for different frequencies can be determined by the proposed adaptive algorithm.
Key words: scroll compressor; axial force; electromagnetic force; advance tracking control