METHOD AND APPARATUS FOR CONTROL OF AN AC ELECTRIC MOTOR WITH FIELD WEAKENING

摘要

A method and apparatus for control of an alternating current electric motor with field weakening, including setting a required operating point (Ud REQ) for a motor field voltage component as a function of a difference between actual (ld FBCK) and required (ld REQ) motor field current components, and setting a required operating point (Uq REQ) for a motor torque voltage component as a function of a difference between actual (lq FBCK) and required (|q LIM_REQ) motor torque current components. The method also includes setting a field weakening constituent (ld REQ_FW) for the required operating point (Ud REQ) for the motor field voltage component as a function of a difference between a required operating point (Uq REQ) and an available value (Uq LIM) of the motor torque voltage component and as a function of a difference between actual (lq FBCK) and required (|q LIM_REQ) motor torque current components.