Research On The Control System Of PMSM Fed By Quasi Z-Source Inverter

As the core component of the air conditioning system,the selection of the type and performance of the drive motor for compressor is particularly important.Due to its high efficiency,high reliability and high power density,the permanent magnet synchronous motor is widely used in the air conditioning compressor system.In addition,the air conditioning compressor system has higher requirements for power conversion module as well.The voltage boost network is often need to realize power factor correction.However,the boost network has some defects,the switching loss is introduced,the use of electrolytic capacitor limits the life of the system,and the shoot-through state of inverter bridge is never allowed.As a novel single-stage topology,quasi Z-source inverter can realize the ability of both DC-DC boost and DC-AC inverter at the same time,while no additional power devices are required.It allows the bridge arm to be shoot-through as well.In this context,this paper mainly studies the permanent magnet synchronous motor control system fed by quasi Z-source inverter:At first,this paper introduces the mathematical model and vector control strategies of permanent magnet synchronous motor.Secondly,the working principle of the quasi Z-source inverter is introduced,the small signal model is built to analyze the dynamic performance,and the voltage and current double closed-loop control structure is introduced accordingly.Several modified space vector pulse width modulation methods with shooting-through zero vectors are introduce,and the simulation under the DC input are given.Then,under single phase AC input system,this paper presents a novel control strategy for electrolytic capacitor-less quasi Z-source inverter,to make the whole system have the capability of both power factor correction and voltage sag resistance,which extends system life as well.Taking permanent magnet synchronous motor as the object,this paper presents a new electrolytic capacitor-less control strategy based on the inverter input power tracking,to improve the input power factor further.The strategy are verified to be ture through simulation under the single AC input system.At last,the hardware experiment platform is built based on the DSP chip MC56F8247,and the hardware circuit module and software architecture are briefly described and analyzed in this paper.The correctness and feasibility of the proposed scheme are verified by hardware experiment.