Failure analysis of low-voltage power and control circuits [power stations]

Circuit protection and alternative approaches are often hard to quantify in advance of design. The author discusses two proven techniques-a probability method using a decision tree and a component damage method for predicting the weakest circuit component. These methods are applicable to circuits typically found in both fossil and nuclear generating stations and provide simple tools for selecting circuitry arrangements or components. The protection circuits used in probability analyses are not necessarily new developments but are representative of applications that exist in many plants. An improvement is indicated in each of the examples discussed