Wound Rotor Asynchronous Motor Starting Process To Analyze And Determine The Starting Parameters

Three-phase asynchronous motor is be used most widely in machine in industry for it's simple structure, reliable capacity, easy to maintain and low rotational inertia . But the starting current is 5 to 10 times to rated current, that will cause machinery and electric equipment damage on the motor or the driven equipment , will decrease voltage of the power system . We must adopt Step-down starting when power capacity is too limited to direct starting. Resistance ,reactor, autotransformer and Y/△ step-down voltage starting can be used to cub modal. These starting methods listed are not perfectly, which is step to step starting. Frequent starting and stopping can not be realized because it create a great impact on the current. Variable rotor resistance starting are adopted for the coiled asynchronous. This method are not perfectly too for it's unreliability. So we use frequent-sensitive resistance as starting component. The component are too easy to damaged at high temperature .Today variable frequency starting ,intelligent soft starting and liquid resistance starting are usually used . It is well known that variable frequency is reliable which be used on huge load. Liquid resistance starting can improve starter specific property with small starting current ,that is not exceed 1.3 times of rated current.In this paper, we analyzed the starting processing of winding asynchronous motor (6KV/4000KW) which is combined liquid resistance starting with variable frequency and variable voltage starting(including calculating power factor,resistance of rotor), that was be using in our actual production ,in theory。In this paper, we build a dynamic mathematic model of three-phase induction motor in A-B-C system and afford some methods which take effect to starting performance of motor concerning saturation effect, skin effect and so on . First we analyzed every starting performance of motor in theory. On base of this , we took account for parameters of voltage, frequency, load , rotational inertia, and changed motor starting parameters, then gave computer simulation to make starting method in...