ENERGY EFFICIENT MOTORS Submitted by: Nishchal Sharma EEE 0581324907

What’s The Need ??? Energy crisis in the world will be one of the factors to impede the economic growth of both developing and developed countries. If new oil and gas reserves are not found, the whole country with a high population growth will have serious problem. The alternative solution to this energy crisis is to optimize the use of available non-renewable energy or to device efficient machines running on renewable energy.

Losses in a Machine winding losses Iron losses 1. Eddy current losses 2. Hysteresis losses Friction losses Windage losses

Energy efficient machines can be designed by….. By redesigning the basic machine structure By selection of energy efficient core and winding materials By interfacing the machine with external devices

Induction Motors Due to easy construction, cheapness, high efficiency, ruggedness induction motors are widely used. Long operating life and almost zero maintenance are added advantages. Almost 95% of the motors used in house hold appliances, industries and commercial enterprises employ induction motors.

Energy Efficient Core Material Normally core loss in a machine is around 30~ 50% of the total losses and about 3% of the machine rating. Using core material having high permeability and low loss. 1.Electrical steel of grades 8050, 8050H, 5350,5350H 2.Using die cast copper cage Die cast copper rotor reduced total energy losses by 15~23%.

Synchronous machines using superconducters Efficiency improvements near 1% Decreased size and weight for equivalent ratings Ability to manufacture larger size generators than is possible with conventional technology Improved steady state and transient system performance Reduced life-cycle costs

Efficiency Optimization using the Skin Effect The skin effect may be utilized to optimize the performance of squirrel cage induction motors. Double cage rotors are used to increase rotor resistance at start up. An outer cage of high resistance material such as brass and inner cage of low resistance such as copper. Outer cage limits the starting current.

Benefit Comparison Power (hp) Energy Efficiency Regulations Minimum Nominal Efficiency  Premium Efficiency motors 1 82.5% 85.5% 10 89.5% 91.7% 25 93.6% 50 93.0% 94.5% 100 94.1% 95.4% 200 95.0% 95.8%

Conclusions Using of improved magnetic materials Replacement of Aluminum cage with Copper cage Design of permanent magnet machines. Utilizing skin effect for efficiency Use of superconducting materials in the machine

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