We operate Brush Electric Machines Frame BDAX-365ER generators equipped with EX2000 PWM digital exciters that are brushless. These exciters were supplied with AVR, FVR, UEL, RCC, OEL, and V/hz limiter as standard features. Optional PSS and VAR/PF controllers were also supplied. The units have the ability to operate in AVR, VAR control, and PF control modes.
NERC requires our synchronous generators to be operated in Automatic Voltage Regulation unless permission is given to operate them otherwise. They also require an annual Reactive Capability test, wherein the units are required to produce the maximum lagging (positive) VARs for a period of 1 hour and, because we are black start capable, the minimum leading (negative) VARs for an instantaneous reading.
And now the issue:
We are limited by the OEL and UEL at +/- 5% of rated generator voltage(13.8 kV). However the manufacturer of the generator says that their machine is capable of +/- 10%.
Are UEL and OEL bypassed when regulator control is in Auto with generator mode in VAR control?
Are they bypassed when regulator is in Manual?
How much does a somewhat high grid voltage reduce the machines ability to produce lagging VARs?
NERC requires our synchronous generators to be operated in Automatic Voltage Regulation unless permission is given to operate them otherwise. They also require an annual Reactive Capability test, wherein the units are required to produce the maximum lagging (positive) VARs for a period of 1 hour and, because we are black start capable, the minimum leading (negative) VARs for an instantaneous reading.
And now the issue:
We are limited by the OEL and UEL at +/- 5% of rated generator voltage(13.8 kV). However the manufacturer of the generator says that their machine is capable of +/- 10%.
Are UEL and OEL bypassed when regulator control is in Auto with generator mode in VAR control?
Are they bypassed when regulator is in Manual?
How much does a somewhat high grid voltage reduce the machines ability to produce lagging VARs?