These motors are designed for the application form requirements of variable speed drive systems. We offer both the subsequent types of motors:

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

Between 500 V and up to 600 V, the motor will need reinforced winding insulation, or the drive must have a du/dt filter.
Above 600 V, the motor will need reinforced winding insulation and the drive must have got a du/dt filter.
If the cable length between the drive and engine is greater than 150 meters and the voltage is between 600 and 690 V, the electric motor will need to have reinforced winding insulation.
A variable-frequency drive is something for controlling the rotational acceleration of an alternating current electric motor. It settings the frequency of the electrical power supplied to the motor. A adjustable frequency drive can be a specific type of adjustable-rate drive. Variable-frequency drives are also known as adjustable-frequency drives (AFD), variable-quickness drives (VSD), AC drives, or inverter drives.

Automatic frequency control consist of an primary electrical circuit converting the alternating electric current into a direct current, after that converting it back to an alternating electric current with the required frequency. Internal energy reduction in the automatic frequency control is rated ~3.5%
Variable-frequency drives are trusted on pumps and machine tool drives, compressors and in ventilations systems for large buildings. Variable-frequency motors on fans save energy by allowing the volume of surroundings moved to complement the system demand.
Reasons for employing automatic frequency control may both be linked to the features of the application form and for saving energy. For instance, automatic frequency control is used in pump applications where the flow is matched either to volume or pressure. The pump adjusts its revolutions to confirmed setpoint via a regulating loop. Adjusting the circulation or pressure to the real demand reduces power usage.
An AC motor acceleration control-also referred to as a adjustable frequency drive, adjustable frequency drive, variable quickness drive, adjustable velocity drive and AC inverter-is an electro-mechanical object that can be used to improve the output acceleration of an AC electric motor by adjusting the input frequency in to the motor.