Permanent Margnet Alternators: Voltage and RPM
It is important for the customers as well as the manufacturers to know the voltage and rpm specifications of the product. But exactly how are they related?
Simply said, voltage generated in an alternator is directly proportional to the speed of the generator or the prime mover; E = K x Flux x speed x turns
That means that on double the rpm of the generator and the AC voltage is doubled. Any permanent magnet alternatorhas its designed RPM at a rated voltage and load condition.
The two factors that go into consideration when planning a complete energy system using permanent magnet generators are the following:
• An increase in rpm will increase the voltage.
• An increase in load will lower the voltage.
There can be two alternators of the same size but a change in the winding will allow one to be designed to run at a low range of RPM and the other designed to run at very high RPM. They could be rated for different power and operate at different V or I.
