WEG New GTA Plus GeneratorMarcelo J. de Oliveira Generator Sales Department WEG Exportadora S.A.

In today's excitation world for brushless typegenerators there are basically a PMG(Permanent Magnet Generator) and a non-PMGgenerator. WEG has developed a generator withthe traditional auxiliary coil or auxiliary winding,but has gone one step further and addedmagnets in the main exciter stator. Thisexcitation system has been called I-PMG(Internal PMG) due to its similar performance to atraditional PMG.

The auxiliary winding is responsible to provideindependent power for the voltage regulatorunder all sorts of load, with no electrical link to themain winding. This way, load application,rejection or any other variation will not impact thepower input for the voltage regulator. WEG'sauxiliary winding ensures 300% of short circuitcurrent up to 10 seconds.

Traditional PMG's are also responsible toprovide the necessary level of residual voltagethat initiates the generation process. In WEG'sGTA design the magnets are imbedded in themain exciter stator, and it generates around 100Vguaranteed versus a no guarantee of up to 15Von a non-PMG generator.

WEG's I-PMG benefits compared to non-PMGgenerators are:- better motor starting capabilities- better performance under loads with high THD- better performance under load variations- short circuit capabilities- quaranteed residual voltage (no need forflashing)

- paralleling ready (unique to WEG on standardgenerators)

WEG's I-PMG benefits compared to traditionalPMG generators are:

- usually shorter envelope (see picture below)- less components for maintenance and cost- easier access to the diodes bridge for monitoringand maintenance (compared to “add-ons”)

- All low voltage 4-pole WEG generators have I-PMG benefits, from 15 to 4200kVA.

- All WEG generators from 50kVAand up have avoltage regulator with paralleling capabilities asstandard.