Permanent Magnet Synchronous Generator

In a permanent magnet generator, the magnetic field of rotor is produced by permanent magnets.

Permanent magnet generators do not require DC supply for the excitation circuit. They do not contact brushes and slip rings. In permanent magnet alternators, speed is directly proportional to voltage of the alternator.

Synchronous generators form the majority source of commercial electrical energy generation. They are used to convert mechanical power output of gas turbines, steam turbines, reciprocating engines, wind turbines, hydro turbines into electrical power for the grid. They are known as synchronous generators as the frequency is directly proportional to the number of permanent magnet stator poles and the rpm.

PMSG for use in Wind Turbines

Of all the generators that are used in wind turbines the PMSGs have maximum merits for the following features:

o Stable
o Secure
o Small Dimension
o Functional without DC supply
o Works at low speed
o Works without gearbox

Permanent magnet synchronous generators make a solution as a variable-speed generator.
PMSG are suitable for use in wind turbines as they are stable and secure during normal operation, have small overall dimensions as compared to wound rotor synchronous generators (WRSGs) and do not require an additional DC supply for excitation circuit or winding. With a multi-pole synchronous generator it can operate at low speeds and in absence of gearbox.