1 Industrial Systems BUS2000 Busbar Differential Protection System Differential overcurrent system with percentage restraint protection

2 Industrial Systems Typical Busbar Arrangements –Single Busbar –Double Busbar with Coupler –Breaker and a Half –Double Breaker –Double Busbar with Transfer Bar –Segregated Busbars with Coupler

3 Industrial Systems Typical Single Busbar Arrangement

4 Industrial Systems Typical Double Busbar with Coupler Arrangement

5 Industrial Systems Typical Breaker and a Half Arrangement

6 Industrial Systems Typical Double Breaker Busbar Arrangement

7 Industrial Systems Typical Double Busbar with Transfer Bar

8 Industrial Systems Typical Segregated Busbar with Coupler

9 Industrial Systems Types of Protection Schemes –Low Impedance –High Impedance Medium Values High Values

10 Industrial Systems Low Impedance Protection

11 Industrial Systems Saturation of the Auxiliary CTs A. Primary Fault Current B. Secondary Current from the Source CTs C. Secondary Current in the Faulty CT D. Differential Current

12 Industrial Systems Low Impedance Protection Current Detection + Second Criteria –Time-delayed Overcurrent Relays –Directional Overcurrent Relays –Restraint Overcurrent relays –CT Saturation Detectors

13 Industrial Systems High Impedance Protection Scheme

14 Industrial Systems High Impedance Protection WHERE: R L = CONNECTION WIRES RESISTANCE I F = SECONDARY RMS CURRENT VALUE IN TI 3 V R = DIFFERENTIAL RELAY VOLTAGE V S = CT MINIMUM SATURATION VOLTAGE V OP = OPERATION VOLTAGE V R = I F x (2R L + R S ) V OP > V R Stability Criteria V S > V OP Operation Criteria TI 3 Totally Saturated R S CT Secondary Winding R Value

15 Industrial Systems Differential Overcurrent Relay with Percentage Restraint & Stabilizing Resistor

16 Industrial Systems BUS2000-External Fault

17 Industrial Systems BUS2000-Internal Fault

18 Industrial Systems BUS Differential Unit Block Diagram

19 Industrial Systems BUS2000-Sensitivity Algorithm (1)

20 Industrial Systems BUS2000-Sensitivity Algorithm (2)

21 Industrial Systems BUS2000-Sensitivity Algorithm (3)

22 Industrial Systems External Fault with CT Saturation

23 Industrial Systems BUS2000-Stability Algorithm

24 Industrial Systems BUS2000-Stability Limit

25 Industrial Systems BUS2000-Operation Characteristic

26 Industrial Systems BUS2000-Auxiliary CT. Magnetizing Curve of the Secondary Side

27 Industrial Systems BUS2000-Alarm Unit Block Diagram

28 Industrial Systems Breaker Failure Block Diagram

29 Industrial Systems Numerical Monitoring Module –Differential and Restraint Currents Metering Information –Full Human-Machine Interface (Keypad + Graphic Display) –IRIG-B Time Synchronization –Alarm Treatment –Differential Protection Outputs Status

30 Industrial Systems Numerical Monitoring Module (cont) –Oscillography Waveform Capture –Event Record –RS232 or fiber optics Communications –Configurable I/O –Undervoltage Supervision

31 Industrial Systems BUS2000-Single Busbar (6 feeders) Differential Protection

32 Industrial Systems BUS2000-Overcurrent and Breaker Failure (5 feeders) Protection

33 Industrial Systems BUS2000-Test Rack

34 Industrial Systems BUS2000-Numerical Monitoring Module

35 Industrial Systems External Connections Diagram of Single Busbar BUS2000 System

36 Industrial Systems BUS2000-Settings –K for Sensitivity –K and RE as low as possible –RE for CT requirements for Overvoltage Conditions

37 Industrial Systems Key Advantages –Flexibility –Independent setttings for K and RE done in the field without any additional changes –Wide Setting Range –Suitable for all kinds of installations –Measurement Units Supervision –Current Circuits Supervision

38 Industrial Systems Key Advantages (cont’d) –Single-Three Phase Breaker Failure –Test Rack Independent from the protection –Easy Commisioning (accesible terminal blocks) –Suitable for updating of old Substations –Operating Principles well proven in the field –Numerical Monitoring Module