Induction Motor Generator Efficiency

A motor is considered.

Induction motor generator efficiency. 5 to 10 hp. Induction generators operate by mechanically turning their rotors faster than synchronous speed. Although high or premium efficiencies may have only a few percentage points better. With rising demand for high efficiency or energy efficient induction motors designers and manufacturers are stepping up their production of such.

A process line consisting of five induction motors 75 hp 150 hp 200 hp and two at 125 hp was identified to monitor the power use and pf of each motor in the process during a normal production cycle. Commercial institutional and particularly industrial operations use substantial amounts of power for electric motors. Peak efficiency is at 7 5 hp. Calculate the efficiency of the motor input power is 55kw and the output power is 45kw.

Slip for ac induction motors courtesy all about circuits induction motors of 50 100 hp for industrial applications vary in weight from 700 to almost 1 000 lbs. Apply our formula motor efficiency 45 100 55 81 8. In most cases this is about 120 of the motor s rated horsepower when operating as a generator. A motor s efficiency tends to decrease dramatically below about 50 load.

Induction motors give best efficiency at their operating point. Normal motors run 50 efficient as a generator baldor motors run in the 80 s. However the range of good efficiency varies with individual motors and tends to extend over a broader range for larger motors as shown in figure 1. The same features that make this motor desirable over the other types of motors makes the induction generator desirable over other types of generators namely the inherent ruggedness of the squirrel cage design and the simplicity of the control systems.

An induction generator or asynchronous generator is a type of alternating current ac electrical generator that uses the principles of induction motors to produce electric power. A regular ac induction motor usually can be used as a generator without any internal modifications. Ie5 energy class is the highest efficiency motor as well as eff3 class motors are the lowest energy class motor. The motor has 81 8 efficiency.

With ever increasing energy cost the life time operating cost of an induction motor can be traded against a high efficiency and high capital cost induction motors. Constant losses are those losses which are considered to remain constant over normal working range of induction motor the fixed losses can be easily obtained by performing no load test on the three phase induction motor. There are two types of losses occur in three phase induction motor these losses are constant or fixed losses variable losses. See the chart below for torque vs.

Constant or fixed losses. Motor efficiency improvement epact was passed in 1992 but motor efficiency provisions took effect in 1997. High efficiency induction motors.