question about paraleling on
question about paraleling on
(OP)
I want to connect two generators to the same step up transformer and then, get 0,90 cos on the connection to the grid...this means each gen set with the same amount of reactive, does somebody do it?





RE: question about paraleling on
The task would be easier if both the gens are identical. This assumes that the grid can absorb the amount of VAR your gens would produce.
Rafiq Bulsara
http://www.srengineersct.com
RE: question about paraleling on
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RE: question about paraleling on
But i still thinking about if there are some problems in the fact of two units working together..
thanks a lot
RE: question about paraleling on
With balanced loads, the voltage from A phase to B phase is at 90 degrees to the current on C phase. However, reactive current on C phase will be in phase with the Voltage from A to B.
The the current from the C phase CT is dropped across a resistor and the resulting voltage added to the sensing input of the AVR.
Real current produces a voltage at right angles to the sensed voltage and it has little effect on the voltage sensed by the AVR.
Reactive current produces a voltage that is in phase with the sensed voltage and it is significant. This feature is built in to many AVRs, but it is basically a resistor and a pair of terminals for the connection of the CT output.
You should be able to find a diagram for a cross current compensation circuit or a quadrature compensation circuit in many textbooks. The instructions with some AVRs include a quadrature compensation circuit.
Bill
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"Why not the best?"
Jimmy Carter
RE: question about paraleling on
This indication of VAR exchange or circulating currents between the generators. You need to ensure that on no-load condition (with grid side breaker open and gen breaker closed), there is no circulating current between the two gens while paralleled with each other.
Rafiq Bulsara
http://www.srengineersct.com
RE: question about paraleling on
When a generator is paralleled with the grid, the grid controls the voltage, the excitation controls the flow of VARs.
Bill
--------------------
"Why not the best?"
Jimmy Carter