Characteristics of permanent magnet synchronous motor

The classification characteristics of permanent magnet synchronous motor one, the characteristics of permanent magnet synchronous motor permanent magnet synchronous motor structure simple, small volume, light weight, small loss, high efficiency, compared with DC motor, it has no DC motor commutator brush other shortcomings. Compared with asynchronous motor, it does need reactive excitation current, so it has high efficiency, high power factor, large moment inertia ratio, low loss of stator current resistance, measurable rotor parameters good control performance. However, compared with asynchronous motor, it also has disadvantages of high cost difficult starting. Compared with the common synchronous motor, it saves excitation device, simplifies structure improves efficiency. PMSM vector control system can achieve high-precision, high dynamic performance, large-scale speed control positioning control, so the PMSM vector control system has attracted the attention of scholars at home abroad.

China is rich in permanent magnetic materials, especially rare-earth permanent magnetic materials Nd-Fe-B resources are very rich in China. The reserves of rare-earth minerals are about 4 times of the total of other countries in the world, known as "Rare Earth Kingdom". The research level of rare earth permanent magnet materials rare earth permanent magnet motors has reached the international advanced level. Therefore, permanent magnet synchronous motor has a good application prospect for our country. 2、 Classification of permanent magnet synchronous motor the geometry of the rotor magnet steel of permanent magnet synchronous motor is different, so the distribution of rotor magnetic field in space can be divided into sine wave trapezoid wave. Therefore, when the rotor rotates, there are two kinds of back EMF waves generated on the stator: one is sine wave, the other is trapezoid wave. So the principle, model control method of two kinds of synchronous motors are different. In order to distinguish the AC speed regulating system of permanent magnet synchronous motor composed of them, it is customary to call the speed regulating system composed of sine wave permanent magnet synchronous motor as the speed regulating system of sine type permanent magnet synchronous motor (PMSM)