Method and device for controlling weak magnetism of permanent magnet synchronous motor

Abstract

The invention discloses a method and a device for controlling weak magnetism of a permanent magnet synchronous motor. The method comprises the steps: reducing the counter potential of the permanent magnet synchronous motor through regulating the set value of d-axis current and the set value of q-axis current under an equivalent rotor coordinate system, wherein the set value of the d-axis current and the set value of the q-axis current are obtained through the following methods: comparing an actual angular speed signal of a rotor with a preset angular speed signal, and performing proportional integral (PI) regulation on a comparison signal to obtain the set toque of the rotor; obtaining the initial set value of the d-axis current according to the set torque; obtaining the regulated value of the d-axis current according to the actual angular speed signal, an output voltage signal and the maximum set voltage value of a traction inverter; obtaining the set value of the d-axis current according to the initial set value of the d-axis current and the regulated value of the d-axis current; and then, obtaining the set value of the q-axis current according to the set torque and the set value of the d-axis current.

Description

technical field [0001] The invention relates to permanent magnet synchronous motor technology, in particular to a field weakening control method and device for permanent magnet synchronous motors. Background technique [0002] In recent years, with the rapid development of power electronics technology, microelectronics technology, new motor control theory and rare earth permanent magnet materials, permanent magnet synchronous motors have been rapidly popularized and applied. The permanent magnet synchronous motor has the advantages of small size, low loss and high efficiency. Today, when energy saving and environmental protection are paid more and more attention, it is very necessary to study it. [0003] The vector control technology of the permanent magnet synchronous motor can make the permanent magnet synchronous motor obtain good transient response characteristics, and realize fast response to load disturbance and change of given value, so it has been widely used. The ...

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Problems solved by technology

And the given value i of the d-axis current obtained above sd * and the given value i of the q-axis current sq * The way of the motor has no direct relationship with the torque of the motor. Therefore, the adjustment of the d-axis current and the q-axis current in the prior art is likely to cause problems such as unstable torque of the motor and poor robustness.

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