ARM Based Variable-frequency Speed Regulation System Of Induction Motors

The development of power electronic technology and computer control technology provide a good prospect for alternating current(AC) variable frequency technology. Because AC speed regulation systems have shown their superiority and huge social benefits, inverters with variable frequency speed regulation technology have more and more exuberant vitality. Variable frequency speed regulation technology is a kind of technologies through changing power supply frequency of AC motor to achieve the purpose of AC motor speed control. Generally speaking, variable frequency control is an ideal method of AC speed control.In this thesis, the development of motor, motor control, the microprocessor and power electronic devices is reviewed. Taking an induction motor as the research object and LM3S811 as the controller, a speed regulation system was designed. In the design, constant voltage frequency ratio control mode was used for its simplicity and effectiveness. The hard part of the designed system includes main circuit and control circuit. And the corresponding software of the system was programmed in language C.The main work contents in my work are listed as follows:(1) The development and classification of motors, the development of AC speed regulation systems and the basic types of speed regulation systems are introduced. After comparisions, the final design scheme is selected.(2) The principles, mathematical models and mechanical characteristics of induction motors are introduced. The principles and characteristics of the constant voltage- frequency ratio control are also studied.(3) The simulation of AC constant voltage frequency ratio control system of induction motors was studied by the MATLAB/Simulink platform.(4) The hardware structure of the control system was designed Including the main circuit, control circuit, drive circuit and protection circuit.(5) The software of the control system was also designed, including the startup program, the main program, the ADC program and the constant voltage-frequency ratio control program.(6) According to some existing problems in my work, some recommendations for futher work in the future are given.