Abstract:
A method of determining a fault direction parameter of a fault on an AC transmission line of a power distribution system relative to a measurement location of the transmission line. The method includes measuring a time-dependent AC current of the transmission line at the measurement location to obtain time-domain current data indicative of the measured current, obtaining a time of the fault on the transmission line, identifying first and second times by identifying a periodically re-occurring feature of the current data, such that the fault time is between the first and second times, extracting, from the current data, an offset indicative parameter indicative of a time offset of the current at the fault time and between the first and second times, calculating an offset direction parameter by comparing the offset indicative parameter to a non-offset indicative parameter, and establishing the fault direction parameter based on the offset direction parameter.
Abstract:
A method of determining a fault direction parameter of a fault on an AC transmission line of a power distribution system relative to a measurement location of the transmission line. The method includes measuring a time-dependent AC current of the transmission line at the measurement location to obtain time-domain current data indicative of the measured current, obtaining a time of the fault on the transmission line, identifying first and second times by identifying a periodically re-occurring feature of the current data, such that the fault time is between the first and second times, extracting, from the current data, an offset indicative parameter indicative of a time offset of the current at the fault time and between the first and second times, calculating an offset direction parameter by comparing the offset indicative parameter to a non-offset indicative parameter, and establishing the fault direction parameter based on the offset direction parameter.
Abstract:
An exemplary method and apparatus are directed to distributed waveform recording for fault monitoring and analysis of a fault condition in a power distribution system. One or more instrument transformers along with merging units and a plurality of Intelligent Electronic Devices (IEDs) distributed in a plurality of hierarchical levels. The distributed waveform recording corresponds to a fault event at different levels in the power distribution system data is carried out by at least two devices configured to detect an event for recording and perform waveform recording. The data used for waveform recording and the data for detection of the event are based on a single stream of the sampled measured value data and are thereby are time synchronized.
Abstract:
A protection relay is disclosed that generates a trip signal to operate a circuit breaker in case of a fault condition. A first module provides measurement and analysis of power parameters of the power line connecting the power equipment that is being protected, the protection being provided by generating a first trip signal for operating a circuit breaker connected in the power line. One or more second modules can boost performance of the protection relay by measurement and analysis of power parameters-to generate a second trip signal for operating a circuit breaker connected in the power line. The first trip signal and the second trip signal are logically combined to generate a trip signal that operates the circuit breaker.
Abstract:
A method of determining a fault parameter of a fault on an AC transmission line 10 of a power distribution system 1 relative to a measurement location 12 of the transmission line 10 comprising: measuring a time-dependent current of the transmission line 10 at the measurement location 12; transmitting a current signal indicative of the measured current to a decision logic section 36, the current signal comprising a plurality of pre-fault current values and a plurality of post-fault current values; determining, by the decision logic section 36, a plurality of phase difference values indicative of respective phase differences between respective pre-fault current values and respective post-fault current values; accumulating the plurality of phase difference values into an accumulated phase difference parameter; obtaining the fault parameter by comparing the accumulated phase difference parameter to a threshold value; and outputting the determined fault parameter.