A Simplified Procedure for Determining the Auxiliary Bus Voltage and Angle During Bus Transfer

During a power station auxiliary bus transfer the bus residual voltage and angle relative to the reserve bus voltage are critical for the first .5 second. A procedure is presented that determines the auxiliary bus voltage during the critical period of the bus transfer. For this simplified procedure a gas fired steam turbine generator auxiliary system is the test case used. The procedure is equally applicable to a nuclear steam turbine generator auxiliary system. The effect of residual motor current is reviewed. Motor speed may also be determined with reasonable accuracy.