information measuring device

Fault Point Locating Function

This device locates the distance from the substation to the fault
point when the occurrence of a breaking current 50F,85F,or 64P
on the line is detected under the basic condition of receiving 54F
open signal when a short circuit or ground fault occurs between
substations for DC electric railway.

Via distant sub-station○○. ○ ○ ○km(km) -km

power command
Substation A

54F opencurrent
detector

Substation B○○. ○kmCurrent
Waveform
communications
department

information measuring device

power supply(section)

54F opencurrent
detector△△. △kmShort circuit andground fault
failureVia distantsub-station

Current
Waveform
communications
department

information measuring device

electrical
wirepower supply(section)rail△△. △km○○. ○kmGPS
antenna
information
measuring device

Current Waveform

information
measuring deviceGPSantennaconnecting line
disconnect device

disconnect device

Purpose and role of the device
Finding the point of failure soonest when a power line failure occurs is an important factor in reducing
downtime.Therefore, it is desirable to shorten the time required to search for failure points from theviewpoint of stable transportation.
In response to this, a new fault locating function has been developed that locates the fault point
based on the ratio of the fault currents in the substations on both sides of the fault point.

Transmission of location results
Fault location results can be transmitted to the power command (via a remote control station) alongwith the fault occurrence time and fault waveform.

Saving and viewing of the results
The results of identification by the information measurement device are stored in the device together
with the time of occurrence and waveform of the failure, and can be viewed on the touch panel
screen of the device.

Information Management
Information stored in the information measurement device, such as labeling results, time ofoccurrence, and fault waveform, can be transferred to a USB memory.
By using the playback software (PC software), it is easy to check and edit the recorded information.

Device configuration
The current waveform at the time of the fault is communicated between the information measurement
devices of each substation, and the fault point is marked from the current ratio.
Fault point determination is possible only with the following devices
Information measurement device ・・・・ for calculating failure points
Current detector ・・・・・・ for measurement of current waveform
Contact circuit breaker ・・・・ for current waveform transmission between substations
GPS antenna ・・・・・・ for time synchronization between information measurement devices

Selection principle
54F

HCT

R1

L1

L2

HCT 54F

R2IALAIB

LBRARBEE

A ssFault Point

B ssD0IA

A ss
T1

T2t

T1

T2t

IB

B ssFig. 1 Principle diagram
The formula for calculating the fault point distance from Substation A is shown in Equation (1).

I B
(D0 + DA + DB ) − DAFault Point Distance =I A + I B...... (1) Equation

D0 =Distance between substations
DA = A substation internal inductance equivalent distance
DB = B substation internal inductance equivalent distance
ΔIA and ΔIB aretime-synchronized averages around the rise of the fault current in both substations
If we assume that ΔIA and ΔIB are the values near the rising edgeE di A 
I A =  =
 dt  t =0 L A + L1E diB I B =  = dt  t =0 LB + L2