基于变压恒频的电梯电机软起动器谐波分析与补偿

Harmonics Analysis and Compensations of Elevator Motor Soft-Starter Based on VVCF

电梯设备中的感应电机通常采用三相六支反并联晶闸管为驱动装置的软起动器来实现电机软起动和能耗降低。在晶闸管强迫换流作用下,定子电压和电流产生大量谐波,会给电机带来损耗甚至影响电梯运行。针对这一问题,以晶闸管驱动感应电机系统为研究对象,建立了该对象的电路数学模型,采用变压恒频(VVCF)模式,计算了各次谐波频谱特性,设计了新的补偿控制律。计算结果和补偿结果通过计算机仿真加以验证,最终试验证明这一方法是有效的。

Induction motors in elevator equipment usually use a soft starter with three-phase six anti-parallel thyristors as the driving device to achieve soft start of the motor and to reduce energy consumption.Under the forced commutation of the thyristor,the stator voltage and current produce certain amounts of harmonics,which bring losses to the motor and even affect the operation of the elevator.Aiming at this problem,taking the thyristor-driven induction motor system as the research object,the circuit mathematical model of this object is established,the variable voltage constant frequency(VVCF)mode is adopted,the harmonic spectrum characteristics of each order are calculated,and a new compensation control law is designed.The calculation results and compensation results are verified by computer simulation,and the experiment proves that this method is effective.