Three-Phase AC Asynchronous Working Principle Of Electric Locomotive

The battery locomotive working principle of three-phase AC asynchronous motors: Three-phase symmetrical windings. When three-phase symmetrical AC power is passed in, a rotating magnetic field will be generated in the space. This magnetic field will cut the rotor conductor, which will generate induced electromotive force and induced current in the rotor. And rotate in the same direction as the synchronous speed.

The frequency of China's industrial electricity (50Hz for civilian use) is 50Hz, and the rotating magnetic field generated is also 50Hz, which is equivalent to 50 / second = 3000 / minute, which determines that the motor speed is 1500 (4 poles) Note: The formula for calculating the motor speed is n = 60f / t Note: n is the motor speed, f is the power frequency, China is 50 Hz, and t is the number of motor pole pairs.

The battery locomotive working principle of variable frequency motor is the same as the working principle of three-phase AC asynchronous motor. The variable frequency motor changes the speed of the motor by changing the frequency of the input three-phase AC power. In a word, the frequency conversion is used to adjust the speed. Ordinary three-phase AC asynchronous motors can also be used as variable-frequency motors. There is no essential difference, except that the frequency-variable motors are optimized for the influence of frequency. The operating frequency of variable-frequency motors is generally 5Hz ~ 100Hz.

Frequency conversion is to change the battery locomotive frequency. The frequency conversion equipment is called frequency converter and Siemens is called vector controller. The original frequency converter simply changed the frequency conversion. The current frequency converter can re-modulate the voltage, current, and frequency, that is, vector control.