Technical characteristics of Customized high torque dc motor
The motors used in the AC system mainly include induction motors and permanent magnet synchronous Motors. Among them, the permanent magnet synchronous motors can be divided into sinusoidal inverse potential permanent magnet synchronous motors and DC motors with Square wave inverse potential according to different working principles., Due to the different working principles of DC motors, their driving current is different from the control method.
The inverse electromotive force of a sinusoidal permanent magnet synchronous motor is sine shaped. For the motor to produce a smooth torque, the current flowing through the motor winding must also be sinusoidal, which must know the continuous rotor position signal. The inverter can provide the motor with sinusoidal voltage or current. Therefore, the permanent magnet synchronous motor needs to use a high-resolution position encoder or a rotating Transformer, and the control algorithm is also more complicated.
The reverse electromotive force of a DC motor is a trapezoidal wave. As long as the motor windings the square wave current, the torque is straight. Therefore, the DC motor does not need a high-resolution position sensor, the feedback device is simple, and the control algorithm is relatively simple. In addition, the air gap magnetic field of the DC motor trapezoidal wave has a higher utilization rate to the iron center than the gas gap magnetic field of the sine wave of the permanent magnet synchronous motor; The DC motor has higher power density and higher output torque per unit volume than the permanent magnet synchronous motor. Therefore, the application and research of permanent magnet DC motor are paid more and more attention
Compared with DC motors and asynchronous Motors, the key technical features of DC motors are:
1, through electronic control to obtain similar DC motor operation characteristics, has a good controllability, wide speed range.
2, need rotor position feedback information and electronic multiphase inverter drive.
3, is essentially an AC motor, because there is no spark and wear problem of the brush and the commutator, can work at high speed, can get higher reliability, long working life, no need for regular maintenance.
4, DC motor power factor is high, rotor without loss and heat, has a higher efficiency: There is data comparison, 7.5 kW asynchronous motor efficiency of 86.4 %, the same capacity of DC motor efficiency of 92.4 %.
There must be an electronic control component, the total cost is higher than the DC motor.
