danzg
Electrical
- Dec 5, 2008
- 1
Hi,
I am involved in excitation system retrofit project for a 800 kVA, 1500 RPM Pelton-driven synchronous generator. The machine now has the classical DC exciter – magnetic amplifier excitation system. Rated excitation is roughly 44 A, 105V (60A, 200V forcing).
One of the proposed variants we are considering consists of a shaft-mounted three-phase PMG (Permanent Magnet Generator) as a source of AC power, a stationary six-pulse diode rectifier and a two-quadrant IGBT-based DC chopper used to control the excitation voltage. As far as we know this particular scheme is not one of the standard off-the-shelf solutions that are offered by major vendors. I would appreciate:
- any experience with similarly sized direct (not brushless) excitation systems supplied from PMG – advantages and disadvantages? What could be pitfalls?
- any experience with excitation systems using choppers in main excitation circuits (I am aware of many available products but those are usually rated 20 Amps or less and basically intended for supply of exciter excitation in brushless systems)
Many thanks
Darko
I am involved in excitation system retrofit project for a 800 kVA, 1500 RPM Pelton-driven synchronous generator. The machine now has the classical DC exciter – magnetic amplifier excitation system. Rated excitation is roughly 44 A, 105V (60A, 200V forcing).
One of the proposed variants we are considering consists of a shaft-mounted three-phase PMG (Permanent Magnet Generator) as a source of AC power, a stationary six-pulse diode rectifier and a two-quadrant IGBT-based DC chopper used to control the excitation voltage. As far as we know this particular scheme is not one of the standard off-the-shelf solutions that are offered by major vendors. I would appreciate:
- any experience with similarly sized direct (not brushless) excitation systems supplied from PMG – advantages and disadvantages? What could be pitfalls?
- any experience with excitation systems using choppers in main excitation circuits (I am aware of many available products but those are usually rated 20 Amps or less and basically intended for supply of exciter excitation in brushless systems)
Many thanks
Darko