The Study Of Controller For Double-Rotors PMSM Used In Underwater Vehicle

The double-rotor motor control system which is used in underwater vehicle has been designed. The cost and reliability are considered. The reasonable scheme has been established based on analysis the technical index as work condition, the power of the motor and the rotate speed. The system has good performance price ratio.In the dissertation, the study status of the underwater vehicle drive system is introduced firstly, the advantage of the double-rotors motor is argumentated. Then, the operation principle and controlmethods of the double-rotors motor are discussed. The mathematical models of propeller torque, underwater vehicle and PMSM with double rotors are established. Based on these work, a feasible project is presented: (1) The CPU is PIC16F877A, current and rotate-speed double closed loop control is adopted, and the PI parameters is calculated. (2) The position detection of rotor adopting at virtual neutral point of electromotor stator, the changing information of the phase of the stator will be obtained. The band-pass filter is employed to get the third harmonic. And based on analysis the detection circuit has phase shift problem, a phase compensation arithmetic is put forward. The stability of the system has been improved. (3) The startup method, a key matter for double-rotors PMSM drives open-loop method called"3-stage startup method"is analyzed in detail, the synchronous approach from the open-loop to the closed-loop is presented.Lastly, the sofware and hardware project of the double-rotors PMSM senseless control system are propsed. The hardware of the control system includes power supply for drive, a third harmonic zero-crossing detecting circuit, an inverter, current and voltage detecting circuit and the keyboard-display circuit. Using the MPLAB as the development platform, the experiments are carried out with investigated methods and matters on drive. The third harmonic phase compensation is validated at the low-speed and high-speed of motor. The experiment showed that the control system could be stable in operation, can satisfy the demand of the underwater vehicle.