China 12v dc gear motor technical characteristics
The electric motor used in the AC system mainly includes two kinds of induction motor and permanent magnet synchronous motor. Among them, the permanent magnet synchronous motor can be divided into a sine wave back EMF and a square wave back EMF according to different working principles. DC motors, because of the different working principle of DC motors, their drive current and control methods can be different.
The back electromotive force of a sinusoidal permanent magnet synchronous motor is sinusoidal. To make the motor produce smooth torque, the current flowing in the motor winding must also be sinusoidal. It is necessary to know the continuous rotor position signal, and the inverter can This provides a sinusoidal voltage or current to the motor. Therefore, a permanent magnet synchronous motor requires a high resolution position encoder or resolver, and the control algorithm is also complicated.
The back electromotive force of the China 12v dc gear motor is trapezoidal. The motor winding only needs to input the square wave current, and 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 is higher than that of the permanent magnet synchronous motor sine wave air gap magnetic field; and the DC motor has higher power density than the permanent magnet synchronous motor, and the output torque per unit volume is larger. Therefore, the application and research of permanent magnet DC motors have received more extensive attention.
Compared with DC and asynchronous motors, the key technical features of DC motors are:
1. Obtained similar operating characteristics of DC motor by electronic control, with good controllability and wide speed regulation range.
2. Rotor position feedback information and electronic multi-phase inverter drive are required.
3, in essence, the AC motor, because there is no spark and wear problems of the brush and the commutator, can work at high speed, can get higher reliability, long working life, no need for frequent maintenance.
4, DC motor power factor is high, the rotor has no loss and heat, there is high efficiency: there is data comparison, 7.5kw asynchronous motor efficiency is 86.4%, the same capacity DC motor efficiency can reach 92.4%.
5, must have electronic control part, the total cost is higher than DC motor.
