Design And Research On Control System Of Ship Propulsive Permanent Magnet Synchronous Motor

In recent years, ship electric propulsion systems have been becoming the major development trend of the dynamic systems in marine engineering due to the advantages of reducing fuel consumption, improving the ship maneuverability and saving space. Because of the advantages of high efficiency, large power density and rapid dynamic response, the permanent magnet synchronous motors have been widely applied to the electric compact propulsion systems. This paper investigates the control scheme and speed performance for ship permanent magnet synchronous propulsion motors.Firstly, this paper constructs the dynamic models of permanent magnet synchronous motors in various coordinates, and the vector control for the ship propulsive permanent magnet synchronous motors is studied. The paper analyzes the load characteristics of ship propellers for establishing the ship-propeller mathematical model. According to the propeller load characteristics and vector control theory, a simulation model established for the overall ship-motor-propeller. The model realizes the ia=0 control strategy of vector control. Moreover, based on theoretical analysis, a hardware design of ship propulsive permanent magnet synchronous motors is proposed, which consists of control circuit based on TMS320F28335 DSP, uncontrolled rectifier bridge and filter circuit, three-phase half bridge inverter bridge and the absorbing circuit, the IGBT driving circuit with M57962L driver chip, and the hardware protection circuit. In CCS3.3 development environment, modular design method is utilized for software design using assembly and C languages. The system software is consisted of three main components, i.e., the initial program, the main program and the interrupt servicing program. Some flow charts and speed and current double-closed-loop controller are introduced in details. The paper proposed a SVPWM algorithm with dead-zone compensation, it effectively suppress the effect of the dead-zone, improves the performance of the system.Finally, a device for variable-frequency driving of mini-type ship electric propulsion is developed, and the output waves and debugging waves are measured for analyzing the detail system performance. Experimental results demonstrate that the control system possesses remarkable steady-state and transient performance, and it is able to achieve the speed control of ship propulsive permanent magnet synchronous motors with high-accuracy.