Summary: | 碩士 === 義守大學 === 電子工程學系碩士班 === 95 === In current stage, there are three kinds of motor used by electric vehicle: brush dc motor, brushless dc motor and switched reluctance motor. Since switched reluctance motor control difficultly, it is much less popular than brush dc motor and brushless dc motor. Because of lower cost, easy to control and control stability, brush dc motor is widely used in building electric vehicle. However, brush dc motor had become more inadequate in later development due to short operating life. On the contrary, brushless dc motor has characters such as high efficiency, excellent reliability, enough locked rotor torque and mature contract technology. Hence, brushless dc motor is becoming to substitute for brush dc motor.
In this thesis, the major core of system is using low-cost microcontroller and all frameworks are building by driver circuit, control sensor feedback circuit, power supply and input/output circuit.
A PID algorithm is used to implement double close loop; current and speed loops. The proposed algorithms can greatly improve the speed controllability and stability. Carefully handle the PWM mechanism provided by the microcontroller, the two closed PID loops could be easily accomplished. Besides the smoothly speed control, the system safety monitoring and driver circuit protecting mechanisms are also considered in this thesis.
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