Southern States Smart Tap User Manual

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> Directional Fault Sensing > Smart Tap

APPLICATION GUIDE

Smart Tap

Fault Location in

Transmission Networks

Fault location and load restoration in transmission networks.

Faults on tapped transmission lines can result in signicant outage times and customer dissatisfaction. Commonly used

substation based fault locating solutions for tapped transmission lines can be problematic when trying to locate the specic

line segment where the fault occurred. Using Smart Tap technology, the fault location information is reported through the

SCADA system allowing the system operator to determine which line segment has experienced the fault.

For momentary faults, the SCADA fault information can assist the crews in the location and elimination of the source

of the momentary fault. For permanent faults, the operator can isolate the faulted section and minimize outage times.

Information from each line tap provides an indicator of a fault and fault direction, it also provides deterministic information

to allow proper sectionalizing.

For example, in a transmission network with four taps, there are nine possible sections where the fault could occur.

• Faulted section is not identied

• Trial and error approach required to clear fault

• For permanent faults, breakers are reclosed into fault to locate faulted

section

• The trial and error approach repeated until proper section is identied

• Not possible to identify sections where momentary faults occur

Smart Tap is an innovative new technology that correctly identies the faulted section for low current momentary

faults and over current permanent faults.

KEY FEATURES

• Detects low current and over current faults

• Detects magnitude and direction of permanent and

momentary faults

• Works on looped transmission lines with radial load taps

• Does not require PTs to determine fault direction

• Direction indication points to faulted section

• Reports information to SCADA operator

• Can be congured for automatic operation

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APPLICATION GUIDE

MOMENTARY OR PERMANENT FAULT

> Directional Fault Sensing > Smart Tap

Line fault between two taps. Smart Tap generates fault direction ags at each sensing point. These ags can be sent to the

SCADA system and displayed on the operators single line diagram. These direction indicators represented as arrows on this

diagram point to the faulted line segment.

PERMANENT FAULT

Faulted Line Section Isolated

In the case of a permanent fault, The SCADA operator can open the switches which will isolate the faulted section after

the breakers have locked out for the remote controlled switches. If the switches are manually operated the crews can be

dispatched to the proper section to isolate the fault without the guess work of trying several locations before the proper location

is identied. The power to the customer can be quickly restored while the crews are clearing the source of the fault.

SSIPOWER SENSORS AND AUTOMATION

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APPLICATION GUIDE

> Directional Fault Sensing > Smart Tap

FAULT SENSING CHARACTERISTICS OF SMART TAP

Low current faults can trip the breaker and be cleared on the instantaneous

reclose operation. Smart Tap detects the direction of these faults and provides

information to the investigative team on the section where the fault occurred. The

detection of the direction of these kinds of faults is very sensitive due to pre-fault

compensation. Small changes in ground current are detected and the direction of

the fault is calculated. This information is not reported unless the substation circuit

breaker trips and a momentary outage exists.

Over current faults can be detected with sudden changes in line current. Pre-

fault compensation allows the over current set points to be set incrementally above

the short term average load current. These direction indications are only reported if

the substation breaker trips out the line.

Smart Tap detects the direction of low current fauts with

the use of pre-fault compensation system which enables

the detection of faults with magnitude less than the current

unbalance in the network.

Smart Tap can work with a variety of current sensing devices.

Conventional CTs and the SSIPower CMD

to 362 KV. Line post sensor devices can be used at 46 KV and

below.

II can be used up

CMD® II Line Post Sensor

Smart Tap does not require the use of high voltage PTs to nd fault direction. Voltage synchronization can be from any AC power source

APPLICATIONS

Substations and

Switching Stations

Manual and Remote

Controlled Switches

SSIPOWER SENSORS AND AUTOMATION

Circuit Switchers

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APPLICATION GUIDE

> Directional Fault Sensing > Smart Tap

System Integration Options

SMART TAP OPERATION

The inputs are from any current sensors capable of providing an analog signal of the current and fault current waveforms.

Potential transformer inputs can be accommodated, if desired but are optional. Smart Tap measures and reports fault

information either to a local RTU or through a self contained communication system to a remote location.

SYSTEM INTEGRATION OPTIONS

Smart Tap provides direction information to SCADA. through local RTU and SCADA communication network. Direction

indicators can be displayed on the SCADA diagrams and to provide information to the operator to guide the sectionalizing

switching steps.

SCADA Display with Fault Direction Indication

RTUs or Modems

Smart Tap can be integrated into the substation and

SCADA networks with the use of optional substation

touch screen HMI servers and ICCP servers available

from SSI Power.

Smart Tap

HMI Server

Smart Tap Application Server

ICCP

DNP

30 Georgia Avenue Hampton, GA 30228 P 770-946-4562 F 770-946-8106 sales@southernstatesLLC.com

www.southernstatesLLC.com

Smart Tap

is a registered Trademark of SSIPower