Development of permanent magnet synchronous motor and armature reaction

There are three types of components of a permanent magnet synchronous motor, namely: machine-side voltage transformer, machine-side current transformer, and excitation transformer. This content has been introduced before, so everyone must have understood it. Moreover, permanent magnet synchronous motors also have frequency conversion equipment for fast current tracking systems, DSP signal processors and high-function neodymium iron boron permanent magnet materials, which have brought unlimited vitality to the development of various types of permanent magnet synchronous motors and their control systems. So what are the development and armature reaction of permanent magnet synchronous motors? Next, the editor will introduce this issue in detail!

Armature reaction:

When the permanent magnet synchronous motor is no-load, there is only one permanent magnet magnetic field rotating at synchronous speed in the air gap, which generates a three-phase symmetrical induced electromotive force in the armature winding. When a three-phase symmetrical load is applied, a three-phase symmetrical current will flow through the armature winding, thereby generating an armature reactive magnetic field. The magnetic field in the motor air gap is generated by the simultaneous action of the armature magnetomotive force and the permanent magnet magnetomotive force.

Compared with the no-load condition, the air gap magnetic field of the motor has changed. The influence of the fundamental wave of armature magnetomotive force on the fundamental wave magnetic field of the air gap is called armature reaction.

The armature reaction changes the amplitude and spatial phase of the air gap magnetic field. In addition to being directly related to the electromechanical energy conversion, it also has a demagnetization or magnetizing effect, which has a profound impact on the operating performance of the motor. The nature of the armature reaction (magnetization, demagnetization or cross-magnetization) depends on the relative position of the armature magnetomotive force and the main magnetic field in space. The phase difference between this relative position, the excitation electromotive force and the load current f (internal power factor angle).

develop:

The permanent magnet synchronous ageless wheel motor and control system are a new generation of green elevator drive equipment. This type of foreign elevator-specific frequency conversion equipment has quite complete software support, can accept the reaction signal of any position sensor, has a self-learning function, actively identifies motor parameters, and actively performs initial positioning when realizing magnetic field oriented servo, and has the same features as DC motors. Excellent linear torque control characteristics. Because of its small size, high efficiency, high power factor, small oscillation, low noise, and good leveling accuracy, it has a large market in high-rise buildings, machine room-less elevators, and household elevators. However, the motor needs to directly output large torque and reduce low-speed torque fluctuations, which poses certain design difficulties.

The driving equipment of electric vehicles, hybrid electric vehicles and electric boats are also permanent magnet synchronous motors. In this kind of application, special attention needs to be paid to the magnetic circuit structure, and a large Xp/Xd value is sought to achieve a large constant power speed regulation range and large dynamic torque.

The permanent magnet synchronous motor has fast dynamic response, hard mechanical properties, ly wide speed range, and a fully digital permanent magnet synchronous servo system with good low-speed stability, accurate position and trajectory control, and is an important execution component in modern automation equipment. , can be widely used in high-precision CNC machine tools, robots, etc. At present, the domestic market is still dominated by imported products.