modern solutions for voltage control in the romanian
TRANSCRIPT
Modern solutions for voltage control in the Romanian transmission grid
Costel Constantin
System Operational Planning DepartmentNational Dispatching Center
October 2019
Voltage control in Romanian transmission grid
Main voltage control objectives:
➢ Maintain an appropriate high voltage profile;
➢ Increase the system voltage stability margin;
➢ Minimize the power system losses;
➢ Optimization of reactive power flow.
Equipments for voltage and reactive power control in transmission grid:
❑ Synchronous generators;
❑ Wind power plants;
❑ On-load Tap changing transformers;
❑ Shunt reactors;
❑ Generators in compensator mode;
❑ Disconnection of transmission OHLs.
Voltage control in Romanian transmission grid
Equipments for voltage and reactive power control:
❑ Synchronous generators:
▪ Generators terminal voltage (NPP, most of TPP and HPP);
▪ Automatic voltage control on the HV busbars (Brazi Vest 400 kV and 220 kV, Lotru 220 kV);
❑ Wind power plants;
▪ Automatic voltage control on the HV busbar 400 kV S/S Tariverde, Rahman, Stupina, Gura
Ialomtei.
Voltage control in Romanian transmission grid
Equipments for voltage and reactive power control:
❑ Synchronous generators:
▪ Generators terminal voltage (NPP, most of TPP and HPP);
▪ Automatic voltage control on the HV busbars (Brazi Vest 400 kV and 220 kV, Lotru 220 kV);
❑ Wind power plants;
▪ Automatic voltage control on the HV busbars 400 kV S/S Tariverde, Rahman, Stupina, Gura
Ialomtei.
-300-275-250-225-200-175-150-125-100-75-50-250255075100125150175200225250275300325350375400425450475500525550575600
380
385
390
395
400
405
410
415
420
425
430
435
440
445
450
P [
MW
], [
Q M
VA
r]
V [
kV]
Statia 400/110 kV Tariverde - Grafic P,Q,V
V1 V2 P Q
30.09.2019
Voltage control in Romanian transmission grid
Equipments for voltage and reactive power control:
❑ Generators in compensator mode in Lotru and Vidraru HPP.
106186.40
507942.65
1242872.30
1729278.06
1660175.81
1346988.82
0
200000
400000
600000
800000
1000000
1200000
1400000
1600000
1800000
2000000
2013 2014 2015 2016 2017 2018
Reactive energy costs for voltage controlin transmission grid [RON]
Voltage control in Romanian transmission grid
Equipments for voltage and reactive power control:
❑ Disconnection of transmission OHLs.
2318559
2896613
2307789
2997835 29556493123315
1514491 13903771260854 1190419 1269757
1509676
0
500000
1000000
1500000
2000000
2500000
3000000
3500000
2013 2014 2015 2016 2017 2018
Disconnection of OHLs from transmission grid for voltage control [hours x km]
400 kV
220 kV
Modern solutions for voltage control
Location of FACTS
devices:
❑ Sibiu Sud 400 kV;
❑ Bradu 400 kV.
Sistem studies:
➢ Steady-state;
➢ Stability analysis;
➢ Power losses study;
➢ Harmonics analysis.
✓ Technology
SVC or STATCOM
✓ Rated Power
Modern solutions for voltage control
✓ Technology
SVC or STATCOM
✓ Rated Power
Feasibility study
▪ Cost-benefits analysis;
▪ Economic efficiency
indicators of investments.
Shunt FACTS devices
Static VAr Compensator
➢ Thyristor controlled reactor (TCR) –
continuously controlled inductance;
➢ Thyristor switched capacitors (TSC) –
switched on/off;
➢ Fixed filters for low order harmonics
filtering.
Static Synchronous Compensator
➢ DC voltage source;
➢ Voltage source converter;
➢ Shunt coupling transformer;
HV bus
Dynamic model of SVC for stability studies
Dynamic model of SVC for stability studies
0 1 2 3 4 5 6 7 8 9 10380
385
390
395
400
405
410
s
kV
[gil1_fSVC] VOLTAGE AT NODE : GIAL41 Unit : kV
[gil1_SVC] VOLTAGE AT NODE : GIAL41 Unit : kVWithout SVC
With SVC
Impact of SVC on oscillations damping
Dynamic model of STATCOM for stability studies
Dynamic model of STATCOM for stability studies
0 1 2 3 4 5 6 7 8 9 10390
395
400
405
410
s
kV
[lss1_EU] VOLTAGE AT NODE : SMIR41 Unit : kV
[lss1_WECC] VOLTAGE AT NODE : SMIR41 Unit : kV
Without STATCOM
With STATCOM
Impact of STATCOM on oscillations damping
Applications of shunt FACTS devices in the
Romanian transmission grid
➢ Voltage control in Sibiu Sud and Bradu areas;
➢ Damping of active power and voltage oscillations;
➢ Voltage and transient stability margins improvement;
➢ Optimization of reactive power flow;
➢ Reduces power losses on transmission lines.