Computer modelling of auxiliary power systems at the Palo Verde nuclear generating station: a new approach

A new method was developed by Palo Verde Nuclear Generating Station (PVNGS) electrical design engineering personnel to update the plant auxiliary power system loading, voltage regulation, and short circuit calculations. Innovative techniques were used to model all significant circuit elements and switching arrangements of the AC distribution system from the switchyard to the terminals of all three-phase load equipment. A computer program was developed in-house to interpret the network model, retrieve component data from existing databases, and generate comprehensive load flow, voltage, and short circuit results. The program provides a means to quickly and easily run “what if” scenarios to analyze any credible plant event. This method has provided plant engineers with a flexible and readily-available tool which has resulted in a better understanding of the distribution system performance and a fully auditable, easy to maintain calculation