The Design And Implement Of Large Intelligent Asynchronous Motor Soft Start Device

The asynchronous motor is widely used in electric drive system, because its structure is compact and simple, its operating efficiency is reliable, its maintenance is convenient and economical. The control method of asynchronous motor has been put in a high priority as the most important drive execution device in industrial production industry. The traditional way to start the asynchronous motor has the shortcoming of starting current and mechanical torque is too large, the overall performance and practicality is poor. Such as the stator resistance string starting method,star-delta starting method,magnetron buck starting method, autotransformer starting method.To solve the problem above, this thesis designed and implemented the large intelligent asynchronous motor soft start device. The main contents are as follows:Firstly, the thesis introduced the principle of motor soft start and choose the model of control core and thyristor.Choosing and designing the soft start main circuit topology, the upper computer system and overall soft start system.Secondly,choosing the soft start controlling method. Obtain the training samples of neural network control algorithm by matlab simulation. Then training the BP and RBF Neural Networks respectively with the same training samples.Thirdly,design the circuit of soft start device. Designing and simulating the thyristor surge circuit,the thyristor trigger circuit, the voltage and current sensing circuit, motor speed measurement circuit.Then simulate the overall soft start device.Fourthly, conduct the design and production of DSP control module. Design the core board and the bottom board of DSP control module PCB. Analysis the EMC of core board PCB before and after manual wiring is finished by Ansoft Designer software.Finish the hardware production of bottom board PCB.Finally, design the upper computer Interface. Design the Login interface,directory interface, serial port setting interface, working condition monitoring interface, soft start controlling interface, working history searching interface and working state history waveform searching interface.In Summary, the thesis complete the design and implement of large intelligent asynchronous motor soft start device.It provides references for start controlling of large asynchronous motor.