The Research And Design On Controller Of Permanent Magnet Brushless DC Motor For Lube Oil Pump

Brushless DC Motor (BLDCM) has many advantages, such as high efficiency and good speedregulating performance. It has been widely used in motion control areas. The control technology ofBLDCM is now relatively mature. However, the research and design of BLDCM controller alwayscost too high, which has restricted its further development. In this paper, a controller used to drive thelube oil pump has been designed. For the maximum production interests, a control system with richerfunctions and lower costs has been designed.In this paper, plenty of domestic and international literatures are checked. The characteristics,working principles, mathematic models and common control strategies of BLDCM controller areanalyzed. And the commutation torque ripple caused by different chopping modes is also beenanalyzed. By contrasting with several control strategies, a system based on special motor control chipand MCU has been proposed, adopting H-on_L-pwm chopper method which causes a smallercommutation torque ripple.Then, a detailed circuit design of system based on MC33035is discussed. The speed feedbacksignal is provided by MC33039, the electronic velometer. In this way, the speed closed-loop controlhas been realized. Three-phase full bridge inverter has been chosen as the main circuit. the controlcircuit to realize the motor Functions such as starting, reversion, braking and speed regulation can areachieved by this controller.For the above pure hardware controller cannot regulate speed accurately, a software systembased on AT89S52is proposed. A new method of using look-up table to realize PI control is proposedin this paper. By this way, the control precision and response of system are both improved. Moreover,circuits like keys, LED display and communication are added, which expanding controller functionsand making the control system more controllable and more hommization. LEDs are driven byTM1620, which saves many I/O ports and improves the utilization rate of AT89S52. And thecommunication is achieved by MAX485, which can realize a remote data transmission.Finally, a simulation model of BLDCM system is established to validate the correctness andrationality of this control strategy. Both steady and dynamic performance of system is improved byadopting closed-loop control. Then, a control system which achieved start, reverse and speed controlis built. Experimental results show that the proposed system is stable, strong anti-interference andcost-effective, meeting the requirements of control system and has a great market application value.