please send me a power point presentation about the topic protection of transmission lines using gps.this is my mail id amma.mouna[at]gmail.com please mail me[/b]
This is a new technique for the protection of transmission systems through the use of global positioning system (GPS) and transients generated by failures. In this scheme, the relay contains a failure transient detection system together with a communication unit, which is connected to the power line through the CVT high voltage coupling capacitors. The relays are installed on each busbar in a transmission network. These detect the high frequency transient voltages generated by failures and record the instant of time corresponding to when the initial waveform generated by the fault reaches the busbar. The decision to fire is based on the components that are propagated through the system. Extensive simulation studies of the technique were performed to examine the response to different power systems and fault conditions. The communication unit is used to transmit and receive digital signals encoded from the local information to and from the associated relays in the system. In each substation, the relay determines the location of the fault by comparing the GPS time measured locally with those received from the adjacent substations, the extensive simulation studies presented here demonstrate the feasibility of the scheme.