FAULT DETECTION IN DUAL MICROPROCESSOR ELECTRONIC TRIP UNIT

摘要

The invention relates to a fault detection method and system in an Electronic Trip Unit (ETU). An ETU includes a Protection Function (PF) and a Metering Function (MF), each of the PF and MF measuring in parallel the same one or more power line parameters. A comparator compares the first measurement and the second measurement and outputs a fault signal when a disagreement is detected with a given level of accuracy between the first measurement and the second measurement. At least one further comparator may be used that compares the first measurement and the second measurement, and a voter circuit that collects signals resulting from each said comparing and detects a fault when at least one fault signal exists among said collected signals.