1. Development basis of permanent magnet synchronous motor
a.Application of high performance rare earth permanent magnet materials
Rare earth permanent magnet materials have gone through three stages: SmCo5, Sm2Co17, and Nd2Fe14B. Currently, permanent magnet materials represented by NdFeB have become the most widely used type of rare earth permanent magnet materials due to their excellent magnetic properties.
b.Application of new control theory
In recent years, control algorithms have developed rapidly. Among them, vector control algorithms have solved the driving strategy problem of AC motors in principle, making AC motors have good control performance. The emergence of direct torque control makes the control structure simpler, and has the characteristics of strong circuit performance for parameter changes and fast torque dynamic response speed. Indirect torque control technology solves the problem of large torque pulsation of direct torque at low speed, and improves the speed and control accuracy of the motor.
c.Application of high-performance power electronic devices and processors
Modern power electronics technology is an important interface between the information industry and traditional industries, and a bridge between weak current and controlled strong current. The development of power electronics technology enables the realization of drive control strategies.
In the 1970s, a series of general-purpose inverters appeared, which could convert industrial frequency power into variable frequency power with continuously adjustable frequency, thus creating conditions for variable frequency speed regulation of AC power. These inverters have soft start capability after the frequency is set, and the frequency can rise from zero to the set frequency at a certain rate, and the rising rate can be continuously adjusted within a wide range, solving the starting problem of synchronous motors.
3. Current technology
a. Permanent magnet synchronous motor design technology
Compared with ordinary electric excitation motors, permanent magnet synchronous motors have no electric excitation windings, collector rings and excitation cabinets, which greatly improves not only stability and reliability, but also efficiency.
Among them, built-in permanent magnet motors have the advantages of high efficiency, high power factor, high unit power density, strong weak magnetic speed expansion capability and fast dynamic response speed, making them an ideal choice for driving motors.
Permanent magnets provide the entire excitation magnetic field of permanent magnet motors, and cogging torque will increase the vibration and noise of the motor during operation. Excessive cogging torque will affect the low-speed performance of the motor speed control system and the high-precision positioning of the position control system.
b.Permanent magnet synchronous motor simulation technology
The presence of permanent magnets in permanent magnet motors makes it difficult for designers to calculate parameters, such as the design of no-load leakage flux coefficient and pole arc coefficient. Generally, finite element analysis software is used to calculate and optimize the parameters of permanent magnet motors. Finite element analysis software can calculate motor parameters very accurately, and it is very reliable to use it to analyze the impact of motor parameters on performance.
Media Contact
Company Name: Anhui Mingteng Permanent-Magnetic Machinery & Electrical Equipment Co., Ltd.
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Country: China
Website: https://www.mingtengmotor.com/