Design And Research Of PMSM Control System For Small Power Ship Electric Propulsion

In recent years, with the development of relating technology, Reliability, efficiency and propulsion power of the marine electric propulsion were improved remarkably, its application scope extends continuously. Now, more and more small ships adopt electric propulsion system, including working ships, tourist ships. In small power electric propulsion system, the thrust motor and its control is the key technology. But now, the motor control products are always imported from other countries. Research and develop this product is important for our country. This paper selects small power motor (about 10-20kW) as the research object, makes a deep research about its control.First, the paper analysis the loading of the electric propulsion system briefly, makes a math model of the hull-propeller, and chooses Vector control technology as the control method. Then, based on theoretical analysis, this paper designs a PMSM control system, and it can be used in small power electric propulsion system. The paper presents the hardware design scheme. The control part uses DSP chip, and it's a special chip for motor control. The drive part uses intelligent power module, it integrated IGBT and protection circuits. These chips simplify the process of design, and improve the reliability of the system. The control part implements these function: out put of PWM single, detecting the position of the rotor and the speed of the motor, also measure the current and communication with the computer. The driver part outputs the three-phase current of the motor, it includes many functional circuits, such as driver circuit, peripheral circuit of IPM, current and voltage measurement circuits. Considering characteristics of the system, this paper uses DSP assembly language to complete the software, and adopts modularized manner to improve the flexibility and transportability of the program. The program can be dividing into four parts: initialization, main loop, main interrupt and communication part. Some flow charts and important models of the software are introduced in details. The paper proposed a dead-time compensation method, it solves the voltage distortion efficiently, benefits the performance of the system. At last, a simulation test about the small power electric propulsion system is made in Matlab/Simulink, result shows the feasibility of the design scheme. Also real experiment about the control system is done with motor testing platform, and result indicates that the control system has excellent dynamic and static performance. These offer a certain value for reference about the deep research of small power electric propulsion system.