异步电机降压起动的起动时间、起动功率和起动损耗

摘要

为了限制异步电机较大的起动电流,经常采用降压起动的方法.但目前对异步电机降压起动的问题研究较少.以电机理论为基础,利用电机的机械特性曲线,分析了异步电机降压Uσ起动时的起动时间、起动功率和起动损耗.设Uσ与额定电压UN之比为降压系数σ(0＜σ＜1),与额定电压UN起动时相比,降压Uσ起动时的起动时间tσ增大到1/σ2,起动功率△Pσ减小到1/σ2,起动损耗△W不变,降压起动不能节能.%In order to limit the larger starting current of induction motor, re duced-voltage startup is used frequently, but up to now, studies of reduced-voltage startup for induction motors have been relatively scarce.Therefore based on the electric theory, and using torque-speed characteristic curve of induction motor, the startup time, startup power and startup loss of induction motor are analyzed when the reduced-voltage Uσ startup.Set the ratio of Uσ to rated-voltage UN is reduced-voltage coefficient σ(0 ＜ σ ＜ 1 ), compared with the rated-voltageUN startup, can get that the reduced-voltage Uσ startup time tσincreased to 1/(σ2) times, startup power APσ reduced to 1/(σ2), startup loss △ W is unchanged, reduced-voltage startup can not be energy-saving.