Study On Drive And Control System Of Five-Phase Pmsm And Fault-Tolerant Operation

With the development of motor control theories, modern power electronics and microelectronic technologies, the motor drive field has exceeded the bondage of standard three-phase power supply system, researching on multi-phase motor drive and control system develops rapidly. Due to the needs of ship propulsion, aerospace, hybrid vehicles applications and high power applications, compared with three-phase motor drive system, multi-phase motor drive system has the adventages of low voltage high power and high availability. Therefore, more and more researchers pay close attention to multi-phase motor drive system. Taking five phase permanent magnet synchronous motor is derived for the object, Five-Phase PMSM mathematical model, vector control system and the fault-tolerant control in the key technologies are researched, the platform of FPGA-based Five-Phase PMSM is constructed, and taking the correlative experiment on the platform.Firstly, this paper establishs the mathematical model of Five-Phase PMSM in the natural coordinate, according to the difference of winding inductors and flux linkage between the sine winding and non-sinusoidal winding Five-Phase PMSM, the Park transformation matrix is derived,and the mathematical model of two winding type Five-Phase PMSM in the synchronization reference frame is built respectively. Secondly, vector control, which applys to the different characteristics of model of the motors with different structures, is studied, according to the different injection currents, this study analyzes the output results of Five-Phase PMSM on the vector control system, which is built by Simulink. Comparative analysis of Near Two Vectors (NTV) SVPWM and Near Four Vectors (NFV) SVPWM from the bus voltage utilization and output voltage harmonic content is done, using Simulink tool proves the correctness of two different SVPWM control.Thirdly, in order to reduce unknown quantity of the optimal phasecurrent under fault conditions, a theory of mirror symmetry is proposed, against three harmonic back EMFs and fundamental harmonic back EMFs for 0.257, by calculating output average power and harmonic power(2ω,4ω,6ω), with zero torque pulsations, zero neutral current and minimum stator ohmic loss as constraint conditions, related equations are established, the phase angles and amplitudes of the currents under faults condition (Single-Phase, Non-adjacent Double-Phase, Adjacent Double-Phase open) are given, the proposed control techniques can successfully operate Five-Phase PMSM under different fault conditions with low torque pulsations and high output torque, and conclusion is verified by using Ansoft simulation. At last, FPGA-based Five-Phase PMSM vector control system of platform is constructed, and power drive circuit is introduced, PI controller, coordinate transformation, SVPWM and SPI module are expounded, and the realization of vector control, two kinds of SVPWM algorithm and fault-tolerant control of Single-Phase open, which are achieved on the platform, demonstrate the feasibility.