These motors are created for the application requirements of variable velocity drive systems. We offer both the subsequent types of motors:

• Constant Torque: Motors particularly designed to handle continuous torque loads, such as for example conveyors, positive displacement pumps, cranes, etc.
• Variable Torque: Motors specifically designed to handle adjustable torque loads such as pumps and fans.
Due to rapid switching and reflections in the cables, motors are at the mercy of more Variable Drive Motor voltage tension in the windings when fed by frequency converters than with sinusoidal supply voltage. The effect of these voltages is definitely an increase as high as 2.5 times the motor’s nominal voltage. This stresses the motor winding insulation and can cause it to breakdown, resulting in feasible sparking. ABB recommends:

Between 500 V or more to 600 V, the motor needs to have reinforced winding insulation, or the drive must have a du/dt filter.
Above 600 V, the motor needs to have reinforced winding insulation and the drive is required to possess a du/dt filter.
If the cable length between your drive and engine is greater than 150 meters and the voltage is between 600 and 690 V, the motor will need to have reinforced winding insulation.
A variable-frequency drive is a system for controlling the rotational velocity of an alternating current electric engine. It regulates the frequency of the electrical power supplied to the motor. A adjustable frequency drive is usually a specific kind of adjustable-quickness drive. Variable-frequency drives are also known as adjustable-frequency drives (AFD), variable-quickness drives (VSD), AC drives, or inverter drives.

Automatic frequency control contain an primary electrical circuit converting the alternating current into a direct current, after that converting it back into an alternating current with the required frequency. Internal energy loss in the automatic frequency control is rated ~3.5%
Variable-frequency drives are trusted on pumps and machine device drives, compressors and in ventilations systems for large buildings. Variable-frequency motors on followers save energy by enabling the volume of air flow moved to complement the system demand.
Reasons for employing automatic frequency control may both be related to the features of the application and for saving energy. For example, automatic frequency control is utilized in pump applications where the flow can be matched either to volume or pressure. The pump adjusts its revolutions to confirmed setpoint with a regulating loop. Adjusting the movement or pressure to the real demand reduces power consumption.
An AC motor rate control-also referred to as a adjustable frequency drive, adjustable frequency drive, variable swiftness drive, adjustable velocity drive and AC inverter-is an electro-mechanical object that can be used to improve the output swiftness of an AC engine by adjusting the input frequency in to the motor.