Study On Vector Control System And Open-phase Fault Tolerant Operation Of Five-phase Dual-rotor Permanent Magnet Synchronous Motor

In recent years, as the need of urban environmental and energy conservation, the electric vechicals(EVs) has attracted more and more attention and research boom. As the key energy conversion components of the EVs, study of the motor is also getting a lot of attention. Motors which used to EVs with the require severse characteristics: high torque density so that reduce the volume occupied by the motor in the car effectively; widely speed-adjust range; good speed performance; high reliability which allowed the motor to continue to work with outputting certain torque for some time. Therefore, the five-phase dual-rotor permanent magnet synchronous motor(DRPMSM), which combines the multi-phase technology and dual-rotor technology, meets all the above described requirements of the motor used in EVs. This article will study high-performance motor control strategy and fault control strategy of the five-phase DRPMSM.Firstly, we will introduce the structure of the motor, which consists of inner motor and outer motor, corresponding to which it has two drive motors: series drive mode and parallel drive mode. Considering mutual inductance matrix of these two sets of windings, mathematical model of the motor is established in the natural coordinate system and in the rotating coordinate system respectively, which provides theoretical basis for xector control of the motor and decoupling controlof the inner motor and outer motor.Secondly, this article investigates high performance motor control strategy under normal operation, which focuses on the space vector control strategy of the motor. On the basis of the three-phase space vector control strategies(SVPWM), we deduces the five phase SVPWM usd for DRPMSM, additional we listed two different five-phase SVPWM(adjacent to the two vector synthesis mode and adjacent four vector synthesis method) modulation methods and compare their performances(Near two vector synthesis mode and Near four vector synthesis method). Since the Near four vector synthesis modulation method can effectively reduce the output harmonic and limit third harmonic current, so this modulation method is used in the experiment verification.Thirdly, all open circuit fault types and corresponding fault tolerance techniques in different drive modes are analyzed. A fault-tolerance control strategy of injecting currents containing a certain third harmonic component is proposed for five-phase DRPMSM to ensure performance after faults in the motor or drive circuit. For adjacent double-phase faults in the motor, based on where the additional degrees of freedom are used, two different fault-tolerance current calculation schemes are adopted and the torque results are compared. Decoupling of the inner motor and outer motor is investigated under fault-tolerant conditions in parallel drive mode. The finite element analysis(FMA) results verify the effectiveness of the techniques.Finally, set FPGA as the control core, we design the five-phase DRPMSM control and drive system. In the controller section, using hardware description language(Verilog), we designed PI controller module, AD converter control module, coordinate transformation module and SVPWM module, and we test each module by simulation or experiment. Finally, we finish space vector of the motor, which verify the effectiveness of verify space vector control strategy of the motor and decoupling of the inner motor and outer motor. Finally, co-simulation results based on Simulink-Simplorer-Maxwell verify the effectiveness of the fault-tolerant techniques proposed in this paper.