The Research Of Chopped-Soft-Starter Based On DSP

Along with the development of power electronic technology and microcomputer control technology,to reduce the big electric current produces the electrical network voltage impact and so on negative influence when the three-phase asynchronous motor starts,the article in view of the present situation of domestic electric motor soft start at present and future trend of development,it expands the realizing method of three-phase exchange asynchronous electric motor chopped wave style.It proceeds many studies including main circuit,controlling circuit,driving circuit and the design of system's software,whose main thought is that pulse controls electronic power switch component IGBT to be on and be off by the fact that DSP produces PWM,it adjusts the empty space ratio and makes the voltage that the stator holds when the electric motor start electric current according to in advance setting up good curve change,so it reduces the starting electric current and realizes the asynchronous electric motor starts.The main task is said as follow:In the first place, the character and harmonious wave of three-phase asynchronous motors is studied. the paper analyses the AC electrocircuit chopper of voltage modulated and the soft starting method.In the second place , three-phase asynchronous motors system is analyzed and simulated with MATLAB, the simulating results basically accord with analyzed results of the paper. the theory of discrete frequency method and saving power are analyzed and simulated. The compareations show the new starting mode of voltage chopper is more excellent and feasible.And then,it introduces the composition structure of the chopped soft wave style and analyses the design of main circuit, controlling circuit, protecting circuit,detecting circuit.Finally the article introduces the designing method of software based DSP and explains the basic method and concrete step that DSP produces PWM.