Induction Generator Reduced Voltage Starting
Induction Generator Reduced Voltage Starting
(OP)
The local utility will not accept the voltage sag produced by a small (750kW) induction generator being connected to their system. The generator breaker is closed after the unit is rotated to synchronous speed by the prime mover. The current inrush is therefore primarily composed of VARS to establish the magnetic field. One option as a method of mitigating this problem is using reduced voltage starting to limit the inrush and resulting voltage sag. The question is how to size the transformer and what configuration/transition of a bypass contactor should be used. Of course economics is an issue, so the smallest possible size transformer is the goal. Does anyone have any good references on this subject?






RE: Induction Generator Reduced Voltage Starting
http://www.puc.state.tx.us/electric/business/dg/dgmanua...
where the Utility suggests hardware for starting the induction generator as an induction motor.
RE: Induction Generator Reduced Voltage Starting
We performed the test by placing a resistor in the CT circuit and recording the current wave form during inrush. Also we recorded machine speed, voltage and breaker position. The test were performed at about 95%, 98% 100% 102% and 105% rated speed.
Perhaps you can test your unit in a similar way to determine the best closing point and decrease your inrush,
jpl.
RE: Induction Generator Reduced Voltage Starting
I like jplinns' idea aswell, I must try it.
RE: Induction Generator Reduced Voltage Starting
What transformer are you refering to? Do you plan to use an Autotransformer type RV starter?
We have provided solid state starters for exactly that application and they work perfectly. A bypass contactor is configured in simple paralell to the SCRs and closes once the SCRs are at full conduction.
"Venditori de oleum-vipera non vigere excordis populi"
RE: Induction Generator Reduced Voltage Starting
RE: Induction Generator Reduced Voltage Starting
RE: Induction Generator Reduced Voltage Starting
RE: Induction Generator Reduced Voltage Starting
http://www.qsl.net/ns8o/Induction_Generator.html
for:
Yes, but... are there problems? Well, there is no active voltage regulation, but keeping it within a tested load rating can keep it within any voltage parameters that you set. I feel that a voltage range between 105 and 126 volts is perfectly reasonable.
RE: Induction Generator Reduced Voltage Starting