JPS60156829U - Earth fault directional relay - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of drawings]

Figure 1 is a bank configuration diagram of a distribution substation, Figure 2 a %
d is a waveform diagram of current and voltage at the time of a ground fault fault, Figure 3 is a block diagram showing an example of a conventional earth fault direction relay, Figure 4 is a phase characteristic diagram of the same ground fault direction relay, and Figure 5 is a diagram of the zero direction relay. Fig. 6 is an equivalent circuit diagram of a phase current transformer, and Fig. 6 is a waveform diagram of a band-pass filter for the fundamental wave. Fig. 8 is a circuit diagram of the passive filter in the same embodiment, Fig. 9 is a waveform diagram for explaining the operation, Fig. 10 is an equivalent circuit diagram of the system when a ground fault occurs, and Fig. 1
Figure 1 is a graph showing the relationship between Kennible's ground capacity and the peak value of the pulse current. ZCT...Zero-phase current transformer, GPT...Grounding instrument transformer, TA and TV...Input transformer, BPF,
and BPF2...bandpass filter for fundamental wave, P
C... Phase comparison circuit, D... Zero-sequence current detection circuit, A
ND...AND circuit, X...output relay, Vl...
- Input limiting clipper (varistor), PF...passive filter, R□ and R2...resistor, C...capacitor.

Claims (1)

[Scope of utility model registration request] The fundamental waves of the zero-sequence current and zero-sequence voltage are extracted using an active bandpass filter, their phases are compared, and the ground that operates the paper power relay is determined when there is a predetermined phase relationship and the zero-sequence current is above a predetermined level. In the short-circuit direction relay, a passive filter or an insert whose circuit constants are selected so that the output is below the upper limit of the dynamic range of the active bandpass filter is installed on the input side of the suctive bandpass filter of the zero-sequence current input section. A ground fault directional relay characterized by: