Power distribution network fault indication system and method

Abstract

The invention discloses a power distribution network fault indication system. The system comprises a voltage monitoring module, a three-phase line monitoring module, a monitoring background and a GPStime service module; the GPS time service module is used for time synchronization; the voltage monitoring module comprises a first GPS time service unit which is connected with the GPS time service module and used for calibrating a clock of the voltage monitoring module; the three-phase line monitoring module comprises second GPS time service units, and the second GPS time service units are arranged on each phase line of a three-phase system of a power distribution network, are connected with the GPS time service module and are used for calibrating a clock of the three-phase line monitoring module; and the three-phase line monitoring module is used for responding to a data interrogation command, acquiring a fault current signal corresponding to a fault moment point and returning the faultcurrent signal to the monitoring background. According to the system of the invention, precise time synchronization and wide-area synchronization are realized, and the fault positioning precision is improved. The invention also discloses a power distribution network fault indication method.

Description

technical field [0001] The invention relates to the technical field of distribution network automation, in particular to a distribution network fault indication system and method. Background technique [0002] At present, distribution network fault indicators are generally required to have the ability to indicate ground faults. Since the zero-sequence current of the fault indicator needs to be obtained through three-phase current synthesis, it is difficult to obtain when the three phases of the fault indicator are out of sync. Accurate zero-sequence current values, especially when the zero-sequence current amplitude is low when the ground is high-impedance. The traditional fault indicator generally uses the electric field sensor signal on the three-phase monitoring module to synthesize and use it as the start signal. Only one phase of the three-phase monitoring module has a GPS timing module, and the other two phases are calibrated by the distance correction method. Therefor...

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Problems solved by technology

[0002] At present, distribution network fault indicators are generally required to have the ability to indicate ground faults. Since the zero-sequence current of the fault indicator needs to be obtained through three-phase current synthesis, it is difficult to obtain when the three phases of the fault indicator are out of sync. Accurate zero-sequence current values, especially at low zero-sequence current amplitudes with high-impedance grounding

The traditional fault indicator generally uses the electric field sensor signal on the three-phase monitoring module to synthesize and use it as the start signal. Only one phase of the three-phase monitoring module has a GPS timing module, and the other two phases are calibrated by the distance correction method. Therefore , the synchronization accuracy of the three-phase monitoring module can only reach 100us level, so the synthesized electric field also has a large error, and it is difficult to use the zero-sequence voltage to start accurately. have a great impact

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