Distributed data acquisition system for substation bus protection and monitoring

A new method for substation bus bar monitoring has been developed using a distributed data acquisition system and fiber optic communications. The advantages of this system include more accurate data sampling, ability to re-create the fault condition with the stored data in a simulation, a more secure transmission system with the use of fiber optics, and to prevent the false tripping of protection breakers. This new system involves current transformers, data acquisition models (DAM), and a data processing model. Each transmission line connected to the substation bus bar will have its own DAM that will sample the transmission lines three phase currents and voltages at the rate of 3,840 Hz. The samples will be converted to a 16-bit digital sample, and sent over a fiber optic network to a data processing module located in the control house. The fiber optic network will utilize a star topology and a custom designed protocol. The DAMs will be synchronized with a clocking signal sent from the data processing model. The data processing model will collect and process the sampled data to check for fault conditions on the bus bar. The data processor will then either trip the circuit breaker or sound an alarm, if a fault condition is detected.