Study Of The Soft Starter With Pump-control Function Based On DSP

The three phase asynchronous motor is most used in industry, agriculture, daily life and etc because of its simple structure, stable running, and lower price. But, high starting current brings when asynchronous motors start up directly, which will take negative influence to electrical equipment and mechanism. Different load has different need of starting characteristics and the specific need is emphasized.In view of the three phase asynchronous motor tradition starting question and the new need of future, the paper introduce a new-style soft starter which based on DSP (TMS320F2812).It has three start modes: the ramp voltage start, the limit current start, and the pump-control start which is different from the traditional soft starter. The soft starter can reduce the water hammer when a pump is started or stopped, and release the vibration of transfer system. Mainly carries on as following works:Firstly, on the basis of the research on the mathematical model of the asynchronous, analyzed the basic principle and control method of the soft starter, it can be found that the water hammer can be decreased or avoided by using the soft starter with torque closed-loop control function.Secondly, Different control method of soft starter was analyzed and simulated by MATLAB. It was proved that the new pump-control function can be realized by torque loop control. In the third chapter, every control scheme and torque measure techniques were discussed.Lastly, the control hardware circuits of the soft starter were built. A chip of TMS320F2812 made by TI Company is the core of the soft start controller. A detail introduction of hardware circuits, such as the power supply circuits, the AC sample circuits, the communication circuits and so on, is given in the following passages. Every software design of control schemes, main program and communication program were introduced, the figures of programs were also given.