Analytical Studies Of Voltage And Current Transients During Fast Bus Transfer In A.C. Auxiliary System Of Thermal Power Station

This paper presents a powerful approach to analyse the voltages and currents during auxiliary bus transfer. A generalized computer program using multi-motor modelling suitable for analysis of a number of motors connected on the unit bus has been developed. In the first part of the study, auxiliary bus voltage decay and phase angle, speed fall of various motors, motor residual voltage and current and bus frequency are investigated at discrete time interval of 0.001 second. In the second part of the study the in-rush currents in the individual motors at different instants of closing of the reserve bus are predicted. Also, the bus-voltage recovery characteristic i s obtained. A test case is also illustrated.