A Coordinated Current Control Method for Electrically Excited Synchronous Motors

Abstract

The invention discloses a current coordination control method of an electrically-excited synchronous motor, which belongs to the field of motor control. In the method, an exciting current, a torque current and a compensation current in a electrically-excited synchronous motor system are defined. Under coordination control of the currents, a stator q shaft current serves as the exciting current and is used for generating an air gap magnetic field so as to keep a stator air gap flux linkage constant; a rotor current serves as the torque current and acts with the air gap magnetic field to generate electromagnetic torque; and a stator d shaft current serves as the compensation current, and a certain proportion relation is maintained between the stator d shaft current and the rotor current, so that a stator air gap magnetomotive force and a rotor air gap magnetomotive force in the direction of a d shaft are cancelled. The realization mode of the method is simple, the magnetic circuit saturation problem under a heavy duty is overcome, the linear relation between the electromagnetic torque and the torque current can be basically maintained if multiple overload torque is output, and the torque output capability is substantially improved; in addition, the torque response speed is greatly improved, and the problem of an insufficient inverter output voltage under the heavy duty condition is solved.

Description

Technical field [0001] The invention belongs to the field of motor control, and particularly relates to a current coordinated control method of an electrically excited synchronous motor. Background technique [0002] In some important applications, such as elevator drives, heavy-duty machine tools, mining machinery, and ship electric propulsion, in order to improve control accuracy and operational reliability, low-speed and high-torque direct drive methods are often used. At the same time, in electric vehicle drives, short-term The intermittent overload operation mode expects the motor to output a high multiple of overload torque. In the occasions where the speed and position dynamic response requirements are extremely high, such as the high-voltage circuit breaker motor driving the operating mechanism, the effective action time is tens of ms. Not only can the motor output multiple overload torque, but the torque response speed can reach the amount of ms. level. Therefore, impr...

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Problems solved by technology

In the existing research on electric excitation synchronous motors, electric excitation synchronous motors with damping windings are more widely used, and damping windings can speed up the torque current response speed, but the air gap flux linkage oriented vector control is very complicated in the dynamic process, and with the At the end of the dynamic process, the current of the damping winding gradually decays, which cannot offset the armature reaction effect of the stator current, and it is difficult to output multiple overload torques solely by the function of the damping winding

However, there are few related researches on electric excitation synchronous motors without damping windings, which mainly focus on the improvement of traditional basic control strategies, and almost no corresponding researches solve the two problems of output torque capability and torque response speed at the same time.

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