Working principle of permanent magnet motor for new energy vehicles

New energy vehicle permanent magnet motors have attracted much attention from all walks of life in the motor industry. They are composed of a motor body and a driver. This type of permanent magnet motor is a typical mechatronics product. It is a DC motor with a magnetic field established by one or more permanent magnets. Its performance is similar to that of a separately excited DC motor with stable excitation current. The speed can be easily adjusted by changing the armature voltage. Compared with separately excited DC motors, this type of motor has the characteristics of small size, high efficiency, simple structure, and less copper consumption. It is also the primary type of low-power DC motor. So what are the working principles of new energy vehicle permanent magnet motors? Next, the editor will introduce it to you in detail!

One of the working principles:

Nowadays, the stator windings of electric motors are ly made into a three-phase symmetrical star connection, which is somewhat similar to a three-phase asynchronous motor. There are magnetized permanent magnets stuck on the rotor of the motor. In order to detect the polarity of the motor rotor, a position sensor is installed in the motor. The driver is composed of power electronic devices and integrated circuits, and its corresponding functions are: receiving the start, stop, and braking signals of the motor to control the starting, stopping, and braking of the motor; receiving position sensor signals and forward rotation signals, which can It is used to control the on and off of each power tube of the inverter bridge to generate continuous torque; it accepts speed instructions and speed response signals to control and adjust its corresponding speed; and provides maintenance and display, etc.

Working principle two:

The position sensor coding of the new energy vehicle permanent magnet motor can make the magnetic field axis position of the energized two-phase windings the rotor magnetic field axis position. Therefore, no matter where the starting position of the rotor is, the motor will produce a large enough starting rotation at the moment of starting. torque, so there is no need for an additional starting winding on the rotor.

Because the stator magnetic field axis can be regarded as perpendicular to the rotor axis, when the iron core is not saturated, the uniform electromagnetic torque generated is proportional to the winding current, consistent with the current-torque characteristics of a separately excited DC motor.

Working principle three:

Because the permanent magnet motor of new energy vehicles operates in a self-controlled manner, it does not have an additional starting winding on the rotor like a synchronous motor that starts under heavy load under variable frequency speed regulation, and it will not vibrate or lose power when the load changes suddenly. step.

For the permanent magnets of small and medium-capacity new energy vehicle permanent magnet motors, they ly use earth neodymium iron boron (Nd-Fe-B) materials with high magnetic energy product. Therefore, the volume of the earth permanent magnet brushless motor is smaller than that of the three-phase asynchronous motor of the same capacity.