AC Motor Speed Control

The applications of AC motors involve mostly in industrial areas wherever these motors are required to control heavy-duty machines. In power plants wherever timeliness & accuracy are very essential for the operation, then AC motors have to be controlled. So, a variety of techniques may be used for controlling ac motor frequency & speed.

 

There are several techniques to control the AC motor speed like altering the number of poles within extremely small increments, altering the motor's slip & altering the AC signal's frequency.

From the above techniques, altering the poles is not used regularly as it is not efficient for frequent control.

 

Another technique like altering the rotor slip of the motor is mostly used once the AC motor is designed mainly for high slip. So by using this technique, this motor should be equivalent to the electric load. So when the power is changed then load speed will be changed. In addition, this load must include extensive inertial components.

 

The most frequently used technique for controlling the speed of an AC motor is altering the frequency of the motor. By using this technique, AC motor drives with variable speed are utilized to change the motor speed which is known as VFD (variable frequency drives), ASD (adjustable speed drives), or AC inverters.

 

A six-step inverter, PWN, or vector flux is used to adjust the AC frequency. A variable voltage inverter or six-step inverter mainly changes the power from AC to DC & after that, it switches to reproduce a sine wave. By using the PWM technique, DC voltage is changed quickly to equivalent "area under the curve."

 

By considering these AC motor speed control techniques, we can operate a power plant where AC motors are utilized to power fans, pumps, etc. These applications need preciseness to maintain an operation running efficiently. The simple technique is to install consistent AC drives which are mainly designed to control the motor speed precisely.

 

These methods are available with different control settings so that one can simply discover speed controls to meet the requirements of your application. The main benefits of ac motor speed controls are the operating of machines can be controlled smoothly, acceleration control, production rates can be adjusted, savings of energy, etc.