Will the speed of high and low voltage motors be different?

A netizen asked, what is the speed of the low-voltage motor? For this problem, we communicate with you from the following aspects.

1. Motor speed is related to pole number and power frequency.

The speed of the motor depends on the number of motor poles and the power frequency. For the power frequency motor, due to the limitation of the power frequency, the maximum speed of the motor, that is, the synchronous speed of the 2P motor, is 3000 rpm. With the increase of the number of motor poles, the speed of the motor is slowing down, so it can only be changed through a reducer if necessary.

Whether it is a high-voltage motor or a low-voltage motor, the rated voltage of the motor will not affect the rotational speed of the motor. However, in view of the mechanical performance characteristics of the related parts and bearings of the motor and the characteristics of the motor structure, it is difficult to manufacture high-voltage and high-speed motors, mainly involving the vibration and electrical performance control of the motor.

2. Variation characteristics of speed of variable frequency motor.

In order to meet the special requirements of different working conditions for the motor speed, in the case that the power frequency motor can't meet it, we can only greatly increase or decrease the motor speed by means of frequency converter, that is, through the frequency of power input by the motor. Compared with the low-voltage motor, due to the limitations of the high-voltage motor matching the inverter, such as the bottleneck technology breakthrough of the inverter and the manufacturing cost, there are relatively few high-voltage variable-frequency motors, that is, the variable-frequency motors are more concentrated in the low-voltage motor, so that the speed range of the low-voltage motor will be very wide, and it may have a particularly high speed, or it may reach a lower speed without a reducer.

However, the characteristics of variable frequency motor running in different frequency ranges are different. In more cases, high frequency operation is more common, and the ultra-low frequency state is only the starting process of the motor, and most of them are close to the power frequency range of the motor.

With the improvement of equipment automation and intelligence, the diversification of motor categories, the combination with other speed regulating components and the linkage of control systems are constantly upgrading and improving, and the speed range of equipment driven by motors will be wider, which naturally puts forward higher requirements for the mechanical properties of related parts.