关键词: 变频器, 异步电机, 电机损耗, 协同优化, 容错控制, 损耗模型

Abstract: Aiming at the problem of isolating the control objectives of asynchronous motors driven by frequency converters under non ideal working conditions, considering the contradictory dependence relationship between switching frequency and motor losses, a fault-tolerant control method was proposed for the coordinated optimization of switching frequency and motor losses of asynchronous motors driven by frequency converters. Analyzing the driving situation of asynchronous motors by frequency converters, in the d-q coordinate system, by injecting second and fourth harmonic components that have been analytically calculated into the stator current,the electromagnetic torque ripple of asynchronous motors under non ideal operating conditions was effectively suppressed; by modulating the fundamental and harmonic components of the rotor magnetic flux through switching frequency modulation,changing the switching frequency affects the magnetic flux and reduces the losses of asynchronous motors, achieving collaborative optimization fault-tolerant control of asynchronous motors. The experimental results show that the studied method can effectively reduce motor losses and improve motor service life during motor operation; and it can efficiently resist external interference to the motor, ensuring normal operation and reducing the number of motor failures,significantly reducing the frequency of failures and downtime.

Key words: frequency converter, asynchronous motor, motor loss, collaborative optimization, fault-tolerant control, loss model