Energy saving
Home » Blog » Energy saving » Improve induction motor efficiency

Improve induction motor efficiency

The efficiency of an induction motor is determined by intrinsic losses that can be reduced only by changes in motor design. Intrinsic losses are of two types: fixed losses - independent of motor load, and variable losses - dependent on load. Fixed losses consist of magnetic core losses and friction and windage losses. Variable losses consist of resistance losses in the stator and in the rotor and miscellaneous stray losses. So by reducing these losses we can improve efficiency of induction motor.

Changing the rotation direction will not improve efficiency.
Core loss and copper, those are the dominant losses. Improve them and you will get better efficiency. Changing the slot shape etc will help considerably, as will using copper in the rotor. BUT, you can't do either one without affecting the performance of the motor, specifically the starting torque and current as well as the maximum torque and current. In addition, if the motor is designed to have aluminum cage, then changing the cage material to copper won't help the efficiency much since the rotor slot and end rings are not optimally designed.

Improving slot fill will help your copper loss, by putting bigger wires in the stator slot, the wire resistance will reduce and the copper loss will go down. Reducing the end turn height of the windings will also help reduce copper losses.
Stray losses are the only one which can improve efficiency without affecting size of the induction motor. This can be reduced by reducing harmonies in the machine, which can be controlled by selecting slot combination, winding layout, size of air gap, saturation, concentricity of air gap etc.

If an induction motor has to run in both direction and uses a bi directional fan it is inefficient. uni directional fans are used in higher ratings to improve efficiency. further direction of rotation is determined by the driven equipment and cannot be changed at will. Minimising losses both core and copper and stray losses, better cooling ,improvement in cooling fan design a combination of all this suitably balanced will improve efficiency but there is always a limitation on max value imposed by certain conditions of application, materials, willingness of customers to pay.

Post a Comment:

    
Calculate (9 * 3) =

You may also like:

There are three different more or less widely used types of constant on-time control. The first one is where the off-time is varied with an error signal. A loop with this type of control has a ...
Grounding (or Earthing) - intentionally connecting something to the ground. This is typically done to assist in dissipating static charge and lightning energy since the earth is a poor conductor of electricity ...
In bushing insulation test there are three major current elements which any of those could affect the test result. These current elements are Capacitive current, leakage current and creepage current. In Tan ...
If there is frequent current-limitation or overcurrent alarm during the variable speed drive running, we should check the loads and inverter IGBT module is normal or not, if its good, then the failure is the ...
Generally, variable frequency drive contains two components: rectifier and inverter. The rectifier converts incoming AC power to DC power, then the inverter converts DC power to the desired frequency AC power. ...
Gozuk Service Gozuk Blog: all about electric motor control & drives industries development in energy saving applications.

Featured

Like pumps, fans consume significant electrical energy while serving several applications. In many plants, the VFDs (variable ... energy consumedA frequency inverter controls AC motor speed. The frequency inverter converts the fixed supply frequency (60 Hz) to a ... Motor starter (also known as soft starter, motor soft starter) is a electronic device integrates soft start, soft stop, ... Soft starter allows the output voltage decreases gradually to achieve soft stop, in order to protect the equipment. Such as the ... Soft Starter reduces electric motor starting current to 2-4 times during motor start up, reduces the impact to power grid during ...

In Discussion