New Technologies in
Transmission
MANJU GUPTA
POWERGRID
May 1, 2012
Issues in Transmission Development
• Right-of-Way (ROW)
Environmental
Wild life sanctuary
Urban areas
• Coordinated development of cost effective Tr.
corridor
• Flexibility in upgradation of transfer capacity
matching with power transfer requirement
• Long distances between Resource Rich areas and
Load centres
Issues in Transmission Development
• Optimisation of investment
• Resettlement and Rehabilitation
• Non-discriminatory open access
Market driven exchanges may influence pattern of power flow
Periodic review and strengthening
Necessitates optimal utilization of existingtransmission infrastructure by enhancingtransmission capacity using emerging technologiesat marginal investment
Technology Integration
To ensure development of Power System in
an optimal manner –
• Enhance the capacity of existing system –
Tr. asset management- using emerging technologies at marginal investment to
get optimal transmission cost
• Technology for new system keeping in view
long-term perspective
To fulfill above objectives, focus in all stages of
Transmission system need to be given
– Planning stage
– Design stage
– Construction stage
– Operation and Maintenance (O&M) stage
– Grid Management stage
Technology Application
High Intensity (MW/m) transmission corridor by increasing
Voltage level
Current order
Both Voltage & Current
Regulation of Power flow by
HVDC
Hybrid AC & HVDC
Flexible AC Transmission devices
Technology Integration at Planning Stage
Road Map for Indian Power System
High Power Intensity Corridor
RoW
(m)
Capacity
(MW)
MW/m
RoW
400kV S/c 52 500 9.6
400kV D/c 46 1000 21.8
765kV S/c 64 2500 39
765kV D/c 69 4000 58
800kV DC 70 6000 85
64 m230 m
1977 1990 2000 2012 2017-18
Voltage
(kV)
Year
220kV400kV
500kV
HVDC
765kV
800kV
HVDC
Increase in Transmission voltage
Complexities with high voltage AC system
• Reactive Power Management
• Availability of switchgear
• Corona Loss
• Sustainability of grid during contingencies
Voltage Upgradation
1200kV
Technology Integration at Planning Stage..contd
Increase in Current Order
Multi Conductor Bundle Line
400kV, 800kV, 1200 kV AC etc.
High Temperature Low Sag (HTLS) Conductor
ACSS (Aluminium Conductor Steel Supported)
ACAR (Aluminium Conductor Alloy Reinforced)
Invar conductor
Gap type conductor
High Surge Impedance Loading Line(HSIL)
Emerging Technology at Design Stage
Transmission line
Tower Structure - Compact / Pole type structure
Reduction in land use by Pole type tower as compared to lattice type
400 kV 220 kV
• Lattice Tower * 9.0 m 6.0 m
• Pole Structure * 1.85 m 1.4 m
* Base width at ground level
Emerging Technology at Design Stage – Substation
Equipment
Space reduction – Compact substation, SAS (S/s
Automation System) having standard communication
models which have inter operability of control &
protection devices
Area : 30-35 Acres Area : 6-8 Acres
Air Insulated S/s (AIS) Gas Insulated S/s (GIS)
Mobile Sub-stations
For faster restoration of supply
Restoration time - 10 to 15 days.
In- Principle acceptance from CERC & Beneficiaries
Aerial Patrolling of Transmission Lines
Ministry of Defense/ DGCA are approached
Use of Unmanned Aerial Vehicle (UAV) is also being explored
National Transmission Management Centre
Remote Operation and control of Trans. Elements / Unmanned
substations.
To enhance Grid reliability while improving Asset Productivity
Reduction in down time
Availability of Experts round the clock
On Line Transformer Monitoring
For prediction of fault in advance
O&M – Upcoming Technology
High Voltage line
Increase the capacity of trans. corridor through HSIL/re-
conductoring with HTLS /Upgradation
Utilisation of transmission lines upto full thermal capacity –
Series capacitors, SVC, FACTS
Optimization of Tower design – tall tower, multi-ckt. tower
GIS substation
EHVAC : 400kV 765kV 1200kV
HVDC : 500kV 800kV
Technology being Adopted
765 KV SUBSTATION AT
SEONI
765 KV SUBSTATION AT SEONI
765 KV SUBSTATION AT SEONI
Impact of Series Capacitor on
Transmission capability
Series Capacitor installation at Raipur
• Combination of FC or
TSC + TCR
• Stabilize voltage in the
systems and controls
overvoltages
• Reduces transmission
losses
Static Var Compensator(SVC)
•
Static Var Compensator(SVC)
• 2 nos. + 140MVAR SVCs
in operation at 400/220kV
Kanpur S/s
•SVCs to be implemented
• +600 / -400 MVAR at
Ludhiana
• +400/ -300 MVAR at
Kankroli
• +300 / -200 MVAR at
New Wampoh
ROW = 85 Mts ROW = 64 Mts
Pole Type TowersPole Type Tower
21
DOUBLE CIRCUIT TOWER MULTI CIRCUIT TOWER
(45 m. High) (70 m. High)
Multi-conductor Bundle line
220 KV S/C Chukha-Birpara line
upgraded with 400/220 KV multi-
circuit line in Jaldapara
Sanctuary without felling of
single tree
220 KV S/C Chukha-Birpara line
upgraded with 400/220 kV multi-circuit
line in Jaldapara Sanctuary without
felling of single tree
72.5
me
tres
75.0
metr
es
Protection of Wild LifeSpecially
designed
high - rise
towers
(75m) to
reduce tree
cutting
(Reduced
from 90000
to 14739 in
Rajaji
National
Park)
Application
of Multi ckt
and Compact
towers to
reduce
corridor
requirement
9 - 25 mtr
50 mtr
4 - 5 mtr approx
Multi-ckt Tower
HVDC Tower
Green Substation
GIS S/s
Hybrid Switchgear
800 kV, 6,000 MW HVDC
1200kV UHVAC
High Temperature Low Sag
(HTLS) Conductor lines
High Surge Impedance Loading
Line
Mobile Substation
Superconductor
Pioneering Efforts
+/- 800 KV HVDC TRANSMISSION LINE
TOWER
B Type Tower
Establishment of 1200kV UHVAC Test Station at Bina
in association with 33 domestic manufacturers
– For indigenous development of 1200KV technology
– Indigenous development of equipments shall help in
• To conduct developmental tests to optimize design of
substation and transmission equipments.
• Indigenous development shall help in reduction of cost and
convenience of O&M
1200 kV National Test Station
38
Satna line
400kV Bina Bus
To 400kV Satna line
1200kV line1200/400kV Transformer
1200/400kV Transformer
400kV line400kV line
Test Station Configuration
1200kV Transformer successfully developed, tested and commissioned.
Test Setup for 1200kV Transformer 1200kV Transformer successfully tested
1200 kV Transformer successfully Developed, Tested and Commissioned
1200kV CVT and LA
72.5 m55m 125 m
Qutab Minar S/C Tower –A type D/C Tower
1200 kV Tower
1200kV Test Station
44
1200kV Test Station
1200kV Gantry Structure
46
A type 55 m
D type
1200kV Towers- S/c
47
Fig: 1200kV bushing mounted on BHEL
transformer at Bina 1200kV National Test Station
Fig: 1200kV BHEL Transformer with cooler assembly fitted
1200kV Transformer
48
1200kV CVT
The initial operational experience of 1200kV Test
Station will prove to be the cornerstone of future
commercial projects
The results and feedback of the various field tests/
trials carried out at 1200kV National Test Station
shall be useful for developing field proven
equipment of 1200KV system in India
India’s first 1200 kV UHVAC Transmission Line
from Wardha to Aurangabad is already under
construction
1200kV Test Station
1200kV Transmission Corridor
• It’s India’s first 1200 kV UHVAC Transmission Line –
400kV Double circuit line upgradable to 1200kV
• Towers and Foundations are designed considering
1200kV parameters
• Tower designs are suitable for operation of two
circuits of 400kV
• Earth-wire to be provided considering 1200kV
• Line insulation to be initially provided for 400kV
• Bunching of conductor bundle along with change of
insulator string to be carried out when upgrading to
1200kV51
1200kV Wardha-Aurangabad Line
52
Nominal Voltage 1150 kV
Highest voltage 1200 kV
Surge Impedance Loading (SIL) 6030 MW
LIWL 2400- Switchgear
SIWL 1800 kV-Switchgear
CFO 1913 kV peak
One min. Power Freq withstand 1200 kV
Electric field at ROW* 4.0 kV/m (criteria less than
5kV/m)
ROW 90 m
1200kV Wardha-Aurangabad Line
• .
53
CONDUCTOR BUNDLE
Conductor-Bundle Octagonal ACSR Moose
ELECTRICAL CLEARANCES
Power Frequency live-metal clearance 2.4 m
Switching Surge Clearance (1.75 p.u.) 8 m
Phase to Phase Switching 24m
Ground Clearance 24m (10kV/m electric
field limit)
1200kV Wardha-Aurangabad Line
400 kV D/C Up-gradable
to 1200 kV AC Tower Configuration
Insulation Level Comparison
5.25
4.15
3.22
2.45
3.06
2.37
1.84
0
1
2
3
4
5
6
245 420 800 1200
System Voltage (kV)
P.U
. LIWL
SIWL
• Handling very huge amount of Power
transfer (6000-8000MW)
• Reactive Power management
• Large size of equipments
• Transport Limitations
• Cost Optimization
Due to the above factors, reduced Insulation Level (margin)
has been adopted for 1200kV system
Challenges in 1200kV Transmission
-3000
-2000
-1000
0
1000
2000
3000
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000
Power Flow (MW)
Re
ca
tiv
e F
low
( M
VA
R)
Reactive Power Characteritics-1200kV Line
Wardha-Aurangabad Line
High Surge Impedance Loading Line(HSIL)
0.457 m
0.457 m
1.1 m
0.9 m
Symmetrical bundle spacing Non-symmetrical bundle spacing
Surge Impedance = 270-300 ohm Surge Impedance = 200-210 ohm
Expanded Conductor Bundle
Sub-conductor
Spacing
457 mm 1000 mm
XL (ohms/km) 0.16178 0.14322
XC (Mohms-km) 0.11032 0.09361
SI (ohms) 134 116
SIL (MW) 1198 1382
Increase in SIL with Sub-conductor Spacing for 400
KV D/C (QUAD MOOSE) LINE
Substation Equipment for
Disaster Management
… ERS-Substation
Snapshots : ERS S/S
ERS S/S - unloading from Aircraft
ERS S/S under transportation
ERS-Substation - Need
POWERGRID has played a vital role in quick restoration
of power supplies across the country by extensive use of
ERS for Transmission Lines. However, there is no quick
restoration means in S/S to cater to an emergency situation.
ERS-S/S readily fills this gap by providing a technological
solution to address the need for:
Disasters damaging S/S
Transformer Failure
Planned transformer outages for internal Inspection
Additional Usage of ERS-S/S
Terrorist attacks & Sabotage
Temporary increase in S/S Capacity
Alternative arrangement in case of delay in S/S commissioning
Address sudden spurt in secure load requirement viz., National Events like Commonwealth games etc.
Superconducting Transmission
Proposal:
“To lay down experimental Super conducting AC
line at 220 kV voltage level to study the feasibility
of Technology in India”
Objective:• To install and operate a superconducting cable
system under realistic conditions in the grid.
• Assessing the performance by carrying out
suitable tests
• Exploring possible application areas
Project Schematic
Indian Power System is characterized by
Large generation addition on continuous basis
Continuous expansion of grid through increasing grid connectivity -
leading to spread of the grid geographically
Power flow in multi direction
Wide variation in generation as well as demand on daily/seasonal
basis
Open Access and frequency linked Unscheduled Interchange (UI)
mechanism in place
Continuous demand for digital grade power and economic dispatch.
Features of Indian Power System
With the above growing aspects in view, it is important to know the
dynamic state of grid in terms of –
Angular and Voltage stability
How much increase in transfer capacity can take place at different instances on
various transmission elements
Control & regulation of power flow to maintain grid parameters
Remedial Action Scheme(RAS) and System Integrated Protection
Scheme(SIPS) for
– In the event of severe contingency occurs/likely to occur which may lead
to grid disturbances, identify what corrective actions to be taken and its
implementation
Above aspects call for development of Smart Grid comprising Wide Area
Measurements (WAM) using Phasor Measurement Unit(PMU), Adaptive
Islanding, Self-healing aspects. This shall facilitate safety, security and
reliability in operation of large & geographically spread grid
Need for Smart Grid
For this, there is a need to develop of intelligent Grid
with State-of-the-Art features like-
– Phasor Measurement Technique
– Wide Area Measurement (WAM)
– Adoptive Islanding
– Self healing Grids
– Probabilistic Assessment, Dynamic Stability Assessment and
Voltage Stability Assessment (VSA) technique etc.
Smart Grid …contd