The Combination And Application Of Permanent Magnet Synchronous Motors With Inverter Technology

The Combination and Application of Permanent Magnet Synchronous Motors with Inverter Technology

Frequency conversion and variable speed control are two very different speed control methods for electric motor products. Variable polarity speed control can only realize multiple speed gears of the same motor, and the corresponding gears correspond to constant speed; while variable frequency speed control can realize smooth transition or soft start of a certain number of poles of motor speed, which can make the motor run stably at any speed.

Permanent magnet synchronous motor is also the use of frequency conversion technology, to achieve the soft speed control of the motor, according to the actual demand of the load automatically adjust the motor speed, to achieve the purpose of energy saving.

Permanent magnet synchronous motor and asynchronous inverter motor has a common point, that is, inverter power supply. Due to the inverter power supply, permanent magnet synchronous motor can achieve soft start and frequency operation, but the inverter software control is different, some inverter manufacturers also introduced a better performance of the permanent magnet motor special inverter.

Permanent magnet synchronous motor is divided into self-starting permanent magnet synchronous motor and frequency control permanent magnet synchronous motor according to the start-up mode, self-starting permanent magnet synchronous motor generally adopts high-performance rare-earth permanent magnet material, with asynchronous start squirrel cage in the structure of the rotor, it can be directly used for power supply at industrial frequency and run at a fixed rotational speed, and it can be powered by frequency inverter and used for speed control condition. Frequency control permanent magnet synchronous motor rotor without winding or start squirrel cage, can not be self-starting, must be driven by special frequency converter, theoretically, the rotor does not heat without loss, energy saving effect is extremely good.

In view of the above, some people may ask: how to choose the permanent magnet synchronous motor? Ms. Sen suggests, should be in accordance with the actual supporting equipment and working conditions: direct replacement of ordinary motors, should be selected from the start permanent magnet synchronous motor; for the starting torque is not high, the main energy-saving fans and pumps to achieve energy-saving loads, can be used to replace the inverter frequency synchronous motor with a self-starting permanent magnet synchronous motor asynchronous motors, and also through the change of inverter frequency The same by changing the frequency conversion parameters modulation ratio or carrier ratio to improve motor performance, can achieve better energy-saving effect; require a wide range of speed control (i.e., wide-frequency operating requirements), high power density equipment, can only be used inverter speed control permanent magnet synchronous motor.

Self-starting permanent magnet synchronous motor application earlier, in the frequency conversion technology is not yet very mature era, small power industrial equipment using self-starting permanent magnet synchronous motor, direct frequency grid power supply, to achieve than the general asynchronous motor energy-saving effect.

From the analysis of energy saving and speed regulation of the overall demand, frequency conversion speed permanent magnet synchronous motor will become an era of motor new favorite. With the increasing popularity of frequency conversion technology, frequency conversion speed permanent magnet synchronous motor will gradually replace the most widely used asynchronous motor into various industries.