A system and method for field-weakening speed regulation of a permanent magnet synchronous motor

Abstract

The invention relates to a system and a method for performing weakening magnetism speed adjustment on a permanent magnet synchronous motor. The system comprises a current feedback computation module, a current loop PI adjustor module, a transformation output module, an advance angle computation module and a torque list searching module, wherein the advance angle computation module computes an advance angle theta lead according to a d axis voltage reference value Vd and a q axis voltage reference value Vq; the torque list searching module converts the q axis voltage reference value Vq to a torque value T, and searches a real q axis current value Iq in the torque list according to the advance angle theta lead and the torque value T; and a real q axis reference voltage instruction V q-real is obtained by conversion. According to the system and the method, the weakening magnetism speed adjustment can be performed on the permanent magnet synchronous motor conveniently by acquiring the torque list of a torque-current relation and searching the torque list according to the computed advance angle, the torque output capability of the motor is used to the greatest extent, and the problem that a current instruction is not accurate due to change of a torque-current coefficient is solved.

Description

technical field [0001] The invention relates to motor drive technology, more specifically, to a system and method for field-weakening speed regulation of a permanent magnet synchronous motor, and a method for obtaining a torque table of the permanent magnet synchronous motor. Background technique [0002] With the advancement of power electronics technology and permanent magnet material technology, the performance of permanent magnet synchronous motors has been greatly improved. Since the air-gap main magnetic field of a permanent magnet synchronous motor is generated by a permanent magnet, which can be adjusted differently from an electric excitation synchronous motor, only by applying a direct-axis field-weakening component in the stator current can the field-weakening speed expansion be realized. However, the traditional field-weakening method increases the direct-axis field-weakening component of the stator current through the PI regulator, which cannot take into account...

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Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a method for obtaining the torque table of the permanent magnet synchronous motor, and to provide a method for obtaining the torque table of the permanent magnet synchronous System and method for field-weakening speed regulation of permanent magnet synchronous motor with torque meter

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