Various magnetic flux-strong magnetic type permanent magnet synchronous motor

Abstract

The present invention discloses a topology structure of a various magnetic flux-strong magnetic type permanent magnet synchronous motor. The motor is an air gap linkage on-line adjustable radial magnetic flux motor, comprises a rotor and a stator iron core which are coaxially arranged from inside to outside, wherein the rotor employs low-coercive force permanent magnetism materials to realize online adjusting of the magnetic steel linkage and avoid that the magnetic steel is demagnetized at the normal work; the rotor armature current needs to include increased magnetic component, and a rotor quadrature-axis magnetic circuit is provided with a plurality of flux barriers to allow the direct-axis inductance to be larger than the quadrature-axis inductance in order to obtain a positive reluctance torque; the rotor employs a structure being the same as a traditional permanent magnet synchronous motor, and when the motor needs speed regulation, the vector control method is configured to lead in direct-axis pulse current in the armature winding for magnetizing and degaussing of the magnetic steel so as to realize online adjusting of the air-gap linkage.

Description

Technical field [0001] The invention belongs to the field of synchronous motor topology, and more specifically, relates to a variable magnetic flux-strong magnetic permanent magnet synchronous motor. Background technique [0002] In recent years, the drive motors for new energy vehicles have mostly adopted built-in permanent magnet synchronous motors (IPMSM), which have the advantages of high power density, good mechanical characteristics, and high speed range. They have received wide attention and attention in the drive system of electric vehicles. application. However, the direct-axis inductance of the built-in permanent magnet synchronous motor is usually smaller than the quadrature-axis inductance. In order to utilize the reluctance torque and achieve field weakening control, the current trajectory is located in the second quadrant. The current always contains a weak magnetic component, which increases the loss and uses the magnetic steel. The rate is low. In addition, afte...

AI Technical Summary

Problems solved by technology

However, the direct-axis inductance of the built-in permanent magnet synchronous motor is usually smaller than the quadrature-axis inductance. In order to use the reluctance torque and realize the field weakening control, the current trajectory is located in the second quadrant, and the current always contains a field weakening component, which increases the loss and the utilization of the magnet. low rate

In addition, after the motor enters the high-speed stage, it is necessary to weaken the motor by increasing the direct-axis demagnetization current component to control the motor terminal voltage not to exceed the limit value of the inverter voltage. At this time, the large field-weakening current makes The copper loss of the motor increases, resulting in a decrease in the efficiency of the motor, and due to the limitation of the power level of the inverter, the current also has a limited value, resulting in a limitation in the degree of field weakening of the motor and a narrow range of speed adjustment

[0003] In the prior art, a mechanical magnetic modulation type permanent magnet synchronous motor is proposed. The mechanical magnetic modulation device is used to change the strength of the internal magnetic field of the motor, thereby reducing the weak magnetic current at high speed and improving the working efficiency of the motor. However, the mechanical magnetic modulation type permanent magnet motor The magnetic adjustment device is relatively complicated, and increases the volume and weight of the entire motor to a certain extent, so it is not conducive to improving the power density and efficiency of the motor

Images