Flux weakening AC motor control by voltage vector angle deflection

摘要

A method for controlling a three phase AC motor includes generating an operating point error signal based upon a difference between a reference operating point and an actual operating point. A first control method is used to determine a first motor control vector, whereby magnitude and angle values of the first control vector are determined. A second control method is used to determine a second control vector from the operating point error signal, whereby the second control vector is a voltage vector with a constant magnitude. A pulse width modulated voltage is applied to the AC motor. The pulse width modulated voltage is dependent upon the first motor control vector when the AC motor is operating below voltage output saturation. The pulse width modulated voltage is dependent upon the second motor control vector when the AC motor is operating at voltage output saturation.

主权项

1. A method for controlling a three phase AC motor, comprising:
generating an operating point error signal based upon a difference between a reference operating point of the AC motor and an actual operating point of the AC motor; using a first control method to determine a first three phase motor control vector from the operating point error signal, whereby magnitude and angle values of the first three phase motor control vector are determined; using a second control method to determine a second three phase motor control vector from the operating point error signal, whereby the second three phase motor control vector is a voltage vector with a constant magnitude and only an angle value of the second three phase motor control vector is controlled; and applying a pulse width modulated voltage to the AC motor, wherein the pulse width modulated voltage is dependent upon the first three phase motor control vector when the AC motor is operating below voltage output saturation, and wherein the pulse width modulated voltage is dependent upon the second three phase motor control vector when the AC motor is operating at voltage output saturation.