| At present,a normal high-speed and high-power air compressor system consists of a low-speed and high-torque induction motor with a geared-up mechanical unit to drive the impeller rotating.If the impeller is directly driven by a high-speed motor,the complicated mechanical gearbox can be removed,which can not only improve efficiency and reliability but also reduce volume,weight and maintenance cost of the system.However,with the speed of rotor increased,the iron loss of the motor increases at the same time,causing the more heat in the motor which is difficultly dissipated and resulting the rotor temperature over safe operation area.Compared with the widespread three-phase induction motor,multi-phase permanent magnet synchronous motor has the advantages of lower rotor loss and higher power density.With the development of power devices and digital signal processors all these years,the inverters for multi-phase motor drive system have been promoted more realizable and reliable.Therefore,in this paper a directly drive turbo system based high-speed triple three-phase permanent magnet synchronous motor is proposed for the application of high-power air compressor,which eliminates the huge gearbox driven by the low-speed and high-torque motor,substituted with a triple three-phase high-speed PMSM driving the impeller directly.Firstly,the stator winding spatial distribution of triple three-phase PMSM is introduced and compared with the usual three-phase PMSM.Then,the regular patterns of harmonic magnetic potential space distribution about any phase generalized multiphase motor are deduced.According to the distribution of air gap magnetic field and stator winding structure,the equivalent circuit of triple three-phase permanent magnet synchronous motor is proposed and its equivalent mathematical model is derived.In order to solve the problem of complex mutual inductance coupling among eighteen stator windings in triple three-phase permanent magnet synchronous motor,the phase currents crossed compensation field-oriented control strategy based on three-phase full-bridge inverter groups is proposed in this paper.After that,another triple three-phase PMSM driving topology based on multi-phase phase-shifting transformers is introduced and researched to reduce the cost of motor drive hardware.The research object in this paper is a 50000rpm/10 k W triple three-phase high-speed permanent magnet synchronous motor drive system which is applied to the air compressor in the aviation environmental regulation system.The corresponding simulation models based on MATLAB/Simulink are established and the effects of proposed control schemes are verified.Finally,a co-simulation model of currents closed-loop control for triple three-phase high-speed permanent magnet synchronous motor is constructed in which MATLAB/Simulink contains phase current control algorithm,Ansys Simplorer contains power drive circuit topology and Ansys Maxwell contains motor finite element electromagnetic simulation model.The winding current response in the finite element electromagnetic simulation is taken as the feedback of the motor drive control algorithm each time step,and the full-bridge inverter power switches drive signals are calculated to control the winding voltage excitation of the triple three-phase PMSM in each simulation step time.The effectiveness and reliability of the proposed control algorithm are verified once again by the co-simulation results,and the comparative analysis of rotor loss of the motor is given.The feasibility and reliability of the proposed control algorithm are verified by the co-simulation results again.The rotor loss of triple three-phase PMSM and three-phase PMSM with the same rated speed and power are compared.Co-simulation results prove that triple three-phase PMSM can reduce the rotor eddy loss so it is suitable for high-speed and high-power applications. |
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