1. PS3: Protection & Control of Series Compensated Networks
Q8 b) What are the requirements of utilities in terms of certification tests for relays and/or protection systems before applying these to series compensated lines?

2. Electricity Supply Network

3. SP AusNet Network
1998
330KV
Double Circuit
225km

4. Project Objectives Compensation: 50 %
DDTS
No 1 line
Compensation: 50 %
Transfer Capability restored to 1500 MW, 36% improvement
Total project cost $A13.5 M
Completion period 14 months
No 2 line
SMTS

5. Capacitor Arrangement
DDTS
SMTS
Bypass Circuit Breaker
Spark Gap
MOV
Discharge
Reactor

6. Distance Relay Problems
Distorted Distance Measurement
Incorrect Directionality (Voltage & Current inversions)
Transient over- and under-reach ( Sub- sychronous Transient Oscillations)
Nonlinear & solid by-passing of capacitors initiate transient changes of :
Voltage magnitude and polarity
Impedance measured

7. Incorrect Reach A B E D C
Line # 2
Line # 1
Line # 3

8. Fault Simulations

10. Internal Fault jX
Forward (operating) reach
dynamic
static
First cycle
Second cycle
Third cycle Z R
Reverse (blocking)
SMTS, No 1 (Faulty) Line Relay, Fault on No 1 line, MOV, no Gap

11. External Fault jX
Forward (operating) reach Z
dynamic
static
First cycle
Second cycle
Third cycle R
Reverse (blocking)
SMTS, No 2 (Healthy) Line Relay, Fault on No 1 line, MOV, no gap

12. Relay Selection 2 x Distance + existing Power Line Carrier
reliable
Under/over reach
transmission time 30ms
1 x Current Diff + new μWave Radio
many faults faster than distance schemes
signal fading

13. Operating Times 1 2 3 5 10 20 30 40 50 60 SMTS Loc 1 Loc 2 Loc 3 Loc 510 20 30 40 50 60
SMTS
Loc 1
Loc 2
Loc 3
Loc 5
DDTS
X SEL/S
X SEL/D
X LFCB/S
X LFCB/D
Y ALPS/S
Y ALPS/D 1 2 3 5

14. Summary Transient fault studies essential for SC Lines
Difficulty to gather data.
Automatic Test Equipment extremely useful design tool
Derived from paper: “Fault simulation studies for protection of series compensated lines”
Adam Klebanowski, GPU PowerNet, Victoria, Australia
Asia Pacific Regional ProTest (DOBLE) User Group Meeting, Melbourne, Australia, 1999