Title: Siemens 7UT6 Differential Protection Relay
1Siemens 7UT6Differential Protection Relay
EEPM 563
Aidil Azwin Zainul Abidin SE 20019 Daniel Andrew
Sen SE 20240 Azlin Aziz SE 20206 Hardanjit S
Gosal SP 20054 Jasni b. Rose SE 20144 Wong Lee
Ming Jolene SE 20207 Renuga Verayiah SE
20237 Rohayiah Mohd Shahuri SE 20241 Sairul
Izwan Safie SE 20221 Wan Noraireen Wan Md
Nor SE 20212 20 November 2005
2The Problem
- Simulation tripping of the Siemens 7UT6
Differential Protection Relay - using MatLab
- for vector groups D0, D1, D5, D6, D7, and D11
- The program allows the user to input protection
parameters, which are then used in the simulation - Graphs showing the phase currents and voltages of
the 3 phases are displayed upon completion of the
simulation
3Background
- Kirchoffs Current Law
- The sum of currents entering a node is equal to
the sum of currents leaving the node
4Common Practice
- A differential protection scheme would usually
include - The differential protection relay itself
- The Current transformers on both primary and
secondary windings - An interposing transformer to compensate
difference in vector and current
5Scope
- This paper will investigate the use of a relay
that will eliminate the use of the interposing
transformer (ICT). - This is significant because
- Vector group compensation for primary and
secondary windings can be done without changing
the ICT. - The calculation of stabilizing resistor, RS for
an earth fault relay can be simplified without
the presence of the ICT.
6Simulink Model
77UT6 Relay Block Diagram
8Vector CompensationMatrix
9Zero Sequence Current Elimination Matrix
10Decision (Trip Logic)
- The relay will trip as soon as it detects a fault
in any one of the three faults. - The future output of the relay would also depend
on the present output. - Once the relay outputs a 0 it continue to output
0 to avoid the breaker from opening and closing.
11D11 Vector Group Single phase to ground fault
12D11 Vector Group Double phase to ground fault
13D11 Vector Group Double phase-to-phase fault
14D11 Vector Group Triple phase fault to ground
15D11 Vector Group Triple phase-to-phase fault
16D11 Vector Group Out of zone fault
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