voltage regulation of genset

[emiluz]

What is the advantage of having a PMG than just getting the supply of the regulator from the stator winding? How does the voltage regulator work for a PMG operated Genset?

 

[dpc]

During a fault or large motor starting, the voltage at the stator can drop to nearly zero, which cuts off the voltage supply to the voltage regulator and exciter. With a PMG, the pilot field of the exciter is powered even with no stator output voltage. This greatly improves generator performance for motor starting, etc. This is especially helpful for standby and emergency generators.

Voltage Regulator works basically the same. Takes ac in and gives dc voltage out that goes to the field of the exciter, generally a rotating brushless exciter.

 

[waross]

A PMG holds the voltage up better and recovers faster under block loading and motor starting. Systems which derive the first stage excitation power from the main generator output may suffer voltage collapse under short curcuit conditions.
The PMG supplies energy to the Automatic Voltage Regulator where it is rectified and sent to the field of the brushless exciter. The stability of the supply energy supply from the PMG is not affected by the stator voltage drops associated with loading.
respectfully

 

[emiluz]

waht is the relationship between the sensing voltage and the voltage from the PMG in a Voltage regulator. which is the supply? the PMG or the sensing?how does the PMG system works?

 

[catserveng]

Basler has a very good technical paper on designing excitation systems that should help answer your questions about basic AVR and excitation system functionallity

http://www.basler.com/downloads/Design_exc.pdf

 

[matrixabc]

some manufactures, don't offer PMG, and they will argue that there is no determent to auxiliary winding over PMG, but they can not guarantee that if the set was left for a long period of time(months) it would excite every time, and you may have to flash the field, but a PMG is guaranteed.