I Brief Introduction

TYHD-AI5/110 OverheadLine Communicable Fault Indicator is applied to  6KV-110kV overhead power line ,is a device to indicate and detect  line fault current,10 years running life of power line fault current indicator , monitoring short-circuit and earth fault, is exposy resin insulated .This system is composed of two parts, one is gathering unit and the other is collection unit.gathering unit monitors line running status real-time. When fault happened ,the gathering unit can quickly locate phase-phase short-circuit area,the fault line and fault point can be judged quickly and accurately.in the meantime, the alarm flag turn red and appear flashlight and the fault signal also be transmitted to collection unit. After receiving signal from gathering unit, the collection unit send the received data to master monitoring station through wireless communication (GPRS/CDMA etc.)

The master station monitoring software analyze the received data and network topology, then to confirm the fault location and appear audible and visual alarm signal, in the meantime, the master station send the analyzed fault information to the operator’s cellphone and help them to find the fault point quickly, it reduces the power-off duration and improve the power supply reliability. Note: gathering unit is named fault indicator and collection unit is DTU originally.

The alarm mode and other parameters can be customized by clients. 

II. principle instruction

1. application principle

The fault indicator’s gathering unit uses gripping structure and coil to induct line current and electrical field signal, these signals are gathered and dealt with through low power consumption single-chip and finish the line load current calculation&short-circuit detection and realize short-distance wireless communication through inner-equipped wireless module with low power consumption,then send the signals to collection unit.

When gathering unit detects that the line current is corresponds to short-circuit characteristics, it immediately transmit the fault information to collection unit nearby through wireless module, in the meantime, alarm appears in means of red flag and flashlight, the collection unit receives every kind of signals then real-time transmit them to the master station monitoring platform through remote wireless communication, the master station will complete the data analysis and fault judgement.

Device application principle is as following diagram:

                  communicable fault indicator application principle

2. fault detection principle:

TYHD-AI5/110 overhead line remote transmission fault indicator is composed of gathering unit and collection unit. gathering units complete the judgement of short-circuit and local alarm;collection unit completes the fault signals and data transmission.

2.1 short-circuit detection principle:

Short-circuit detection adopts load current self-adaption intelligent sudden changes method. According to the characteristics of short-circuit, it judges the fault through electromagnetic inductive method to detect the sudden changed current in line and sudden changed current duration,it is a kind of fault detection device which automatically adapts to load current changes and only related with short-circuit current component.The short-circuit detection principle is that the line current will change as the following diagram when fault happen

• From running current sudden changed to fault current, that is, there is a positive △I change.
• 

               fault indicator short-circuit judgement criteria

• Current protective appliance of Upstream circuit-breaker will drive the circuit-breaker triggered or the fuse wire is fused out, its fault current existing duration is the fault current clearance duration of circuit-breaker(=protective appliance alarm time+switch alarm time+fault current arc failure time), or fusing time of fuse cut-out.
• (3) Line is powered off, the line current and voltage is decreased to zero.

According to this characteristic, the short-circuit detection criteria of self-adaption short-circuit fault indicator can be summarized as following

(1) △IF＞Iset

(2) T1＜△T＜T2

(3) IH＝0,UH＝0

In the above, △IF is fault current component or current variable quantity, Iset is interior default value, there is a little difference for different type of indicator installed in different site.△T is fault lasting time,T1,T2 are interior default value,it is determined by system’s protection and switch performance; T1 is the fastest time that the fault is cleared,T2 is the most possible longest duration required for fault clearance ,IH,UH are current and voltage value after fault.the above judgment criteria can be described as: when line current gets a positive sudden change,its changed quantity is above a certain setting value, then the current and voltage decreased to zero in a short time, then the line current is judged as fault current. Obviously, it is only related with short-circuit current component when fault happen and there is not direct relation with line current value in normal working status. So it is a fault detection device which can adapt to load current changes. Its judgement criteria is comparatively complete and can largely reduce the possiblity of mis-alarm.

III Functions

1. gathering unit introduction

• fault indication
• short-circuit and earth fault indication: when short-circuit or earth fault happened,the gathering unit in the correspoding phase of the fault line area detects the fault and sends out the alarm indication.
• Fault alarm is transmitted remotely: the fault alarm information is outputted in the means of wireless communication.
• intelligent reset:
• permanent fault: automatically reset after power restore in a very short time
• transient fault: automatically reset, the reset time can be configured as 4,8,12,24 hours before delivery.
• Anti-misalarm for load wave: in the status of non-fault wave for line current, the gathering unit will not mis alarm the fault.
• Automatically avoid switching-in rush current : when line is powering switch(or recloseing),the gathering unit installed this line can escape the rush current and not mis-alarm.
• recloser minimum recognition time:
• the gathering unit can recognize the transient fault with the recloser duration of 0.2 seconds and can alarm accurately.
• The gathering unit installed in non-fault branch will not mis-alarm when sense recloser rush current after experiencing 0.2 seconds of recloser interval power outage.
• Live install and uninstall:the gathering unit for overheadline can be installed and uninstalled lively, in the duration of operation,it will not mis-alarm.

2. collection unit introduction

• wireless receiving data:Receiving fault point signals transmitted from gathering unit through short-distance wireless network.
• Remotely wireless public network sending: Through GSM/GPRS in the means of alternate mode sending the siganls of working status , gathering unit status, fault information to the master station and make sure the line running status is transmitted reliably.
• Support multi-power supply: power supply setting is flexible. rugular equipped is solar panel. single-phase power taking PT also can be equipped.
• flexible stand-by power supply equipped :5AH/8AH/12AHFlexible stand-by power supply equipped: using solar panel power supply mode, equipped with free-maintanance of 5AH/8AH/12AH storange battery and super capacitor,the storage battery can keep the collection unit working continously 30 days in the condition of battery fully incharged; Also adopts to PT supply mode,equipped with 40F super capacitor and make sure data can be uploaded reliably after power off. Note: For 110KV system, solar panel is recommended.
• communication is chooseable:IEC60870－5－101 or 104 can be chooseable to connect the third party device or scada system to upload fault and load current information.
• remote upgrade:software program upgrading remotely is supported.
• easy maintenance:Parameters can be configured easily by Wireless setting device and to make upgrading maintanance .
• Events record: 1000 pieces of events can be recorded maximum and can provide abundant data support for system fault analysis.
• Hearbeat can ne configured: every kind of information in working status can be transmitted to master station regularyly, the transmitting time can be self-defined.
• Clock synchronization and timing : support master station software protocals or Beidou satellite, GPS clock timing function,the collection unit clock error is less than 1s.

IV Technical specification

1. invironemenatal index:

• ambient temperature:-40～70℃
• Relative humidity:5～100%
• atmospheric pressure:70kPa～106kPa
• altitude:＜2000m
• pollution grade:not lower than grade V.

2. System index:

• System voltage:≤110kV
• System frequency:50Hz
• conductor cross-section:35～240 mm²
• suitable for maximun over-current protection delay:3S

3. Main technical performance and parameters

3.1 gathering unit

• short-circuit judgement accuracy rate:100%
• short-circuit alarm current minimum lasting time recogizable:between 20ms～40ms
• alarm error:short-circuit alarm starting error≦±10%,
• wilrless communication distance:≤20 meters
• Average power consumption:＜30μA
• Running life:running continuously 10 years
• net weight:≤0.5kg
• protection grade:IP68

3.2 collection unit

• rated working voltage:DC 6V/DC 12V
• connection numbers for gathering units:9 pcs of gathering units；
• timing accuaracy:≤1s/24h；
• average non-fault time(MTBF):＞70000 hours
• communication module equipped:4G/3G/2G
• solar panel capacity:≧12W(equipped by local standard)
• stand-by battery capacity:≧12AH(equipped by local standard)
• Protection grade:IP65
• size and dimention:height×width×thickness=388mm×366mm×368mm
• weight:＜5Kg
• installtion mode:hoop fixation

    Insatalltion and uninstallation

Insatallation

a) By fitting the bracket installed in the hot sticks, screw detaching sheet nut to let the sheet fully retracted into the interior of the column (ie: try to tighten the sides, leaving enough space so as not to block the indicator when installing).

b)put the indicator into the bracket , and make the spring device to hook with the indicator spring, and rotate the spring device down firmly until after the indicator spring pulled position retractor can hook, then hook the spring with retractor and pull t he spring device out. And use the same method to the other side of the same end of the indicator spring to hook retractors.

c) Aligning the overhead lines pushed up and under the pressure of the overhead lines the indicator springs are divorced from the retractor spring and stucked overhead lines firmly.

removal

a)Install the bracket in the hot sticks,and let the hook outward open, and screw detaching sheet nut to let the sheet leaned out of the column.It is best to made the screws on both sides of the detaching sheet leaving 4-5 buckle (wire length).

b) lift bracket alignment the fault indicator installed in the overhead line and hard pushed up, so that the fault indicator clipped in the bracket, forced to drop down the hot sticks, the indicator can be removed.

Note: This device can be made by client's requirment for different parameters.