We all know that the frequency converter is a power control device that uses frequency conversion technology microelectronics technology to control AC motor by changing the working power supply frequency of the motor. Simply put, the motor uses the frequency converter to adjust the speed. So, in the age of no frequency converter, how is the motor to achieve speed adjustment? Explosion-proof motor manufacturers today to give you a popularization of this problem, do understand the look over!
When there was no frequency converter, it was basically the world of DC motor speed regulation system, if the last century before the 1960s, when the thyristor was born, it was still driven by the generator to speed the DC motor. The following Xiaobian will give you three kinds of speed regulation:
Slip speed regulation: is the meaning of "slip" to speed regulation, the actual motor speed is unchanged after starting, it is through the "slip head" between the motor the load to slip, so that the speed on the load side is lower.
Pole change speed regulation: In addition to frequency conversion speed regulation, there is actually a debugging method, that is, by changing the number of poles to achieve speed change, such as the four-pole motor speed of 1,500 revolution, the eight-pole is only 750 revolution.
Dc motor speed control system: as long as the size of the armature current is adjusted, you can directly achieve accurate torque control of the motor, which can easily meet the control requirements of constant torque, which is also the root cause of the DC motor speed control system low speed torque is very good.