变频调速电动机最佳起动频率选择

Selection on Optimum Starting Frequency of Variable-Frequency Adjustable-Speed Motor

分析了PWM控制电压型变频器供电变频调速电动机,在不同的起动频率下起动时,电动机转动转矩和起动电流的变化规律,以及由于高次谐波引起的趋肤效应使定、转子导体电阻阻值显著增加对电动机起动特性的影响,寻找到既满足电动机起动转矩要求,又不超过变频器过载电流的最佳起动频率范围。

For variable-frequency adjustable-speed motor fed by voltage inverter controlled by PWM, the variable regulation of starting torque and starting current at different starting frequencies are analyzed. The influence of skin effect caused by high-order harmonic on starting performance of motor is described also. The optimum starting frequency range, which meets requirements of starting torque and does not exceed overload eurrent of inverter, is discovered.