Impressive Efficiency Results obtained during tests conducted by PM Generators Ltd.

PM Generators Ltd. is best known for its world class permanent magnet alternators and best quality products. PM Generators Ltd. has further taken steps to maintain their competency in the industry by conducting efficiency tests the results of which continue to prove that PMGL manufactures the most efficient products in the industry.

Need of the tests
PM Generators Ltd. makes sure that only the best products are manufactured at its facility. For this purpose it conducts research and development of newer designs with increased efficiencies and better outputs. Similar tests were conducted to test the efficiencies obtained at varying speeds for a recently built permanent magnet alternator. These alternators are perceived as the future of renewable energy generation. Hence it is all the more important to develop more efficiency in this field.

Process of Conduction of Tests

Efficiency is output by input in terms of percentage. For a permanent magnet alternator, the output is in the form of electrical energy and the input is mechanical energy. So it was basically needed to measure the two results, the input and the output to calculate the efficiency. Since the output is electrical, the loaded voltage and current are measured. The input side is mechanical energy which is generally provided by a motor. The factors to be considered here are speed and torque. All these quantities help to calculate the efficiency of the machine.


The alternator tested was rated at 750rpm. The required efficiency was not only at the rated speed but also at half speed and the customer’s cut-in speed. At the rated rpm, the PMGL alternator achieved 95% efficiency. At 400 rpm it was over 90% efficient and was 74% at 200rpm.

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The efficiency of more than 90% at less than the rated speed is worth noting. All alternator models at PM Generators Ltd. give very high efficiencies between 85% and 95%.