Exciters and PMG

Brushless exciter systems

- For electrics alternators -

PMG RES20008

specializes in Brushless exciter systems for power stations alternators and produces machines from 20 KW (600 mm diameter) to more than 300 KW (2400 mm diameter) covering the entire market needs .

The Exciters which we offer are designed to be assembled directly on the shaft of the main alternator without modification. They are provided with a rotating rectifier bridge and they are adapted to each alternator : Electric characteristics, shaft diameter, mechanical fixations. Furthermore, they can replace existing commutator exciters on hydraulic alternators in order to obtain a brushless system.

Exciters for power stations alternators.

exciters are made as follows :

• The rotor is assembled directly on a main alternator shaft, and is constructed with a varnished electrical lamination , windings are made of enameled wire or copper bars and which are fixed to the rotating rectifier bridge.
• The stator is manufactured with magnetic lamination . The number of poles define the frequency of exit (between 4 and 80 poles, according to the nominal RPM of the main alternator).
• Low speeds, from 100 to 1800 RPM, for hydraulic applications or diesels.
• Hight speeds, from 3000 to 3600 RPM, for turbo alternators.

Excitateur RK 12014

Exciters associated with the rotating rectifier bridge

The current generated by the exciter must be rectified to be injected into the polar wheel of the main alternator, it's the job of the rotating rectifier. It consists generally of 6 diodes and can be equipped with over voltage protection or other safety devices.
Optimum reliability is obtained by use of a rectifier equipped only with diodes. Exciter stator is fed by a voltage regulator.

Electric diagram.

The exciters can be supplied with P M G :

Exciter system with P M G (permanent magnet generators).

Exciters for Hydro-electric Power Stations :

The majority of hydro-electric power stations were built before 1970. Today with new technologies, these power stations can increase their production of energy by 20% by renovating the unit harnesses alternator. The infrastructure is preserved, this relatively inexpensive solution is used worldwide.
With these modifications, the exciter system easily be modified to brushless system.

is one of the few companies worldwide who can offer the transformation of these original exciters to brushless exciters by re-using the original magnetic circuit thus cutting costs.


have already renovated any power stations worldwide.

Exciters for hydraulic production             Exciters for turbo-alternator

specializes in exiters and PMG.

We can provide new alternators for hydraulic production or for renewing machines.
We can also offer a total solution for you including voltage regulators.

PMG rotor

The advantages of Brushless exciters :

• No maintenance
• No replacement of brushes.
• No pollution in main the alternator and exciter.
• Better insulation of the main alternator.
• Increased alternator life.
• Possibility of autonomous functioning of the block with a PMG alternator
• The restoration, replacement of rings or exciter comutators with brusless exciters.

Exciter rotor with rectifier bridge for hydraulic machine   Exciter rotor in placewith main alternator 1500 RPM on balancing tool

Exciter rotor for tubo alternator 3000 RPM

Asynchronious exciter in place on motor

Exciteur with rectifier bridge and PMG

• To download the PMG EMG-EMCO documentation.
• To download the PMG Catalogue.
• To download the Excitaters & PMG general documentation.
• To download the Excitaters & PMG documentation.
• To download the principle of Excitaters & PMG.
• To download an exemple of an EMG Exciter.
• To download an other exemple of an EMG Exciter.
• To download hydro examples.
• To download an exemple of a convertion to PMG.