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
existing
transmission
infrastructure
by
enhancing
transmission capacity using emerging technologies
at 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
Technology Application

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 Integration at Planning Stage
 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
High Power Intensity Corridor
Road Map for Indian Power System
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
230 m
64 m
Increase
in Transmission
voltage
Voltage
Upgradation
1200kV
Voltage
(kV)
765kV
800kV
HVDC
500kV
HVDC
400kV
220kV
1977
1990
2000
Complexities with high voltage AC system
• Reactive Power Management
• Availability of switchgear
• Corona Loss
• Sustainability of grid during contingencies
2012
Year
2017-18
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
• Lattice Tower *
• Pole Structure *
* Base width at ground level
400 kV
9.0 m
1.85 m
220 kV
6.0 m
1.4 m
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
Air Insulated S/s (AIS)
Area : 30-35 Acres
Gas Insulated S/s (GIS)
Area : 6-8 Acres
O&M – Upcoming Technology
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
Technology being Adopted
 High Voltage line
 EHVAC : 400kV  765kV  1200kV
 HVDC : 500kV  800kV
 Increase the capacity of trans. corridor through HSIL/reconductoring 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
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
Static Var Compensator(SVC)
• Combination of FC or
TSC + TCR
• Stabilize voltage in the
systems and controls
overvoltages
• Reduces transmission
losses
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 Pole
Type
Towers
Type
Tower
DOUBLE CIRCUIT TOWER
1
MULTI CIRCUIT TOWER
2
(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 multicircuit line in Jaldapara
Sanctuary without felling of
single tree
75.0 metres
72.5 metres
Protection of Wild Life
Specially
designed
high - rise
towers
(75m)
to
reduce tree
cutting
(Reduced
from 90000
to 14739 in
Rajaji
National
Park)
50 mtr
9 - 25 mtr
4 - 5 mtr approx
Application
of Multi ckt
and Compact
towers to
reduce
corridor
requirement
Multi-ckt Tower
HVDC Tower
Green Substation
GIS S/s
Hybrid Switchgear
Pioneering Efforts

800 kV, 6,000 MW HVDC
 1200kV UHVAC
 High
Temperature
Low
Sag
(HTLS) Conductor lines
 High Surge Impedance Loading
Line
 Mobile Substation
 Superconductor
+/- 800 KV HVDC TRANSMISSION LINE
TOWER
B Type Tower
1200 kV National Test Station
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
substation and transmission equipments.
of
• Indigenous development shall help in reduction of cost and
convenience of O&M
Test Station Configuration
400kV line
400kV line
Satna line
400kV Bina Bus
1200kV line
1200/400kV Transformer
1200/400kV Transformer
To 400kV Satna line
38
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
1200 kV Tower
72.5 m
Qutab Minar
55m
S/C Tower –A type
125 m
D/C Tower
1200kV Test Station
1200kV Test Station
44
1200kV Gantry Structure
1200kV Towers- S/c
A type 55 m
D type
46
1200kV Transformer
Fig: 1200kV BHEL Transformer with cooler assembly fitted
Fig: 1200kV bushing mounted on BHEL
transformer at Bina 1200kV National Test Station
47
1200kV CVT
48
1200kV Test Station

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 Transmission Corridor
1200kV Wardha-Aurangabad Line
• 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
1200kV
51
1200kV Wardha-Aurangabad Line
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
52
1200kV Wardha-Aurangabad Line
CONDUCTOR BUNDLE
• .
Conductor-Bundle
Octagonal ACSR Moose
ELECTRICAL CLEARANCES
Power Frequency live-metal clearance
Switching Surge Clearance (1.75 p.u.)
Phase to Phase Switching
2.4 m
8m
24m
Ground Clearance
24m (10kV/m electric
field limit)
53
400 kV D/C Up-gradable
to 1200 kV AC Tower Configuration
Insulation Level Comparison
6
5.25
5
4.15
P.U.
4
3.06
3.22
LIWL
SIWL
3
2.37
2.45
1.84
2
1
0
245
420
800
System Voltage (kV)
1200
Challenges in 1200kV Transmission
• 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
Reactive Power Characteritics-1200kV Line
3000
Recative Flow ( MVAR)
2000
1000
0
0
-1000
500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000
Power Flow (M W)
-2000
-3000
Wardha-Aurangabad Line
High Surge Impedance Loading Line(HSIL)
Symmetrical bundle spacing
0.457 m
0.457 m
Surge Impedance = 270-300 ohm
Non-symmetrical bundle spacing
1.1 m
0.9 m
Surge Impedance = 200-210 ohm
Expanded Conductor Bundle
Increase in SIL with Sub-conductor Spacing for 400
KV D/C (QUAD MOOSE) LINE
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
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
Features of Indian Power System
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.
Need for Smart Grid
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(SIPS) for
Scheme(RAS)
and
System
Integrated
Protection
– 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
Smart Grid
…contd
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.