The document summarizes power blackouts that occurred in India on July 30-31, 2012. It provides background on India's power grid system and describes how planned line maintenance and failures of other lines led to overloading and eventual tripping of multiple transmission lines, resulting in the first blackout on July 30th affecting 8 states. Efforts to restore power are also outlined. The second larger blackout on July 31st affecting 21 states is also summarized, including impacts like trapped miners. Technical recommendations to prevent such widespread outages are mentioned.
Indian grid system is a synchronized system and presently operating as National Grid. India has five provincial grids altogether as per geological region which covers the distinct states electrical power framework to be specific these are Northern Grid, Eastern Grid, Western Grid, Southern Grid and North-Eastern Grid. Southern Grid isnt synchronized with whatever is left of the areas and consequently keeps running on a marginally different frequency and associated with Western Grid and Eastern Grid through HVDC links. A power outage is the total or partial loss of energy to a territory and is the most serious type of blackout that can happen. Power outage is a transgression to the interconnected power framework. At the point when interconnected power framework goes out of step, it is basic and essential to distinguish it quickly, and islanding ought to be taken to counteract boundless power outage. Two extreme power outages influenced the greater part of northern and eastern India on 30th and 31st July 2012. The 30th July 2012 power outage influenced more than 300 million individuals and was the then-biggest power blackout ever, tallying number of individuals influenced, beating the January 2001 India power outage. Within the 24 hours of restoration of this, another blackout strokes the northern part of the country. The outage of 31st July is the biggest power blackout exceeding the previous one. Abhay Nath Dubey | Dr. Deepika Chauhan | Md. Asif Iqbal"A Case-Study on Blackout" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-3 , April 2018, URL: http://www.ijtsrd.com/papers/ijtsrd11287.pdf http://www.ijtsrd.com/engineering/electrical-engineering/11287/a-case-study-on-blackout/abhay-nath-dubey
Power Quality is a combination of Voltage profile, Frequency profile, Harmonics contain and reliability of power supply.
The Power Quality is defined as the degree to which the power supply approaches the ideal case of stable, uninterrupted, zero distortion and disturbance free supply.
High Voltage Direct Current technology has certain characteristics which
make it especially attractive for transmission system applications. HVDC
transmission system is useful for long-distance transmission, bulk power delivery and
long submarine cable crossings and asynchronous interconnections. The study of
faults is essential for reasonable protection design because the faults will induce a
significant influence on operation of HVDC transmission system. This paper provides
the most dominant and frequent faults on the HVDC systems such as DC Line-to-
Ground fault and Line-to-Line fault on DC link and some common types of AC faults
occurs in overhead transmission system such as Line-to-Ground fault, Line-to-Line
fault and L-L-L fault. In HVDC system, faults on rectifier side or inverter side have
major affects on system stability. The various types of faults are considered in the
HVDC system which causes due to malfunctions of valves and controllers, misfire
and short circuit across the inverter station, flashover and three phase short circuit.
The various faults occurs at the converter station of a HVDC system and
Controlling action for those faults. Most of the studies have been conducted on line
faults. But faults on rectifier or inverter side of a HVDC system have great impact on
system stability. Faults considered are fire-through, misfire, and short circuit across
the inverter station, flashover, and a three-phase short circuit in the ac system. These
investigations are studied using matlab simulink models and the result represented in
the form of typical time responses.
Indian grid system is a synchronized system and presently operating as National Grid. India has five provincial grids altogether as per geological region which covers the distinct states electrical power framework to be specific these are Northern Grid, Eastern Grid, Western Grid, Southern Grid and North-Eastern Grid. Southern Grid isnt synchronized with whatever is left of the areas and consequently keeps running on a marginally different frequency and associated with Western Grid and Eastern Grid through HVDC links. A power outage is the total or partial loss of energy to a territory and is the most serious type of blackout that can happen. Power outage is a transgression to the interconnected power framework. At the point when interconnected power framework goes out of step, it is basic and essential to distinguish it quickly, and islanding ought to be taken to counteract boundless power outage. Two extreme power outages influenced the greater part of northern and eastern India on 30th and 31st July 2012. The 30th July 2012 power outage influenced more than 300 million individuals and was the then-biggest power blackout ever, tallying number of individuals influenced, beating the January 2001 India power outage. Within the 24 hours of restoration of this, another blackout strokes the northern part of the country. The outage of 31st July is the biggest power blackout exceeding the previous one. Abhay Nath Dubey | Dr. Deepika Chauhan | Md. Asif Iqbal"A Case-Study on Blackout" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-3 , April 2018, URL: http://www.ijtsrd.com/papers/ijtsrd11287.pdf http://www.ijtsrd.com/engineering/electrical-engineering/11287/a-case-study-on-blackout/abhay-nath-dubey
Power Quality is a combination of Voltage profile, Frequency profile, Harmonics contain and reliability of power supply.
The Power Quality is defined as the degree to which the power supply approaches the ideal case of stable, uninterrupted, zero distortion and disturbance free supply.
High Voltage Direct Current technology has certain characteristics which
make it especially attractive for transmission system applications. HVDC
transmission system is useful for long-distance transmission, bulk power delivery and
long submarine cable crossings and asynchronous interconnections. The study of
faults is essential for reasonable protection design because the faults will induce a
significant influence on operation of HVDC transmission system. This paper provides
the most dominant and frequent faults on the HVDC systems such as DC Line-to-
Ground fault and Line-to-Line fault on DC link and some common types of AC faults
occurs in overhead transmission system such as Line-to-Ground fault, Line-to-Line
fault and L-L-L fault. In HVDC system, faults on rectifier side or inverter side have
major affects on system stability. The various types of faults are considered in the
HVDC system which causes due to malfunctions of valves and controllers, misfire
and short circuit across the inverter station, flashover and three phase short circuit.
The various faults occurs at the converter station of a HVDC system and
Controlling action for those faults. Most of the studies have been conducted on line
faults. But faults on rectifier or inverter side of a HVDC system have great impact on
system stability. Faults considered are fire-through, misfire, and short circuit across
the inverter station, flashover, and a three-phase short circuit in the ac system. These
investigations are studied using matlab simulink models and the result represented in
the form of typical time responses.
Unit I: Introduction to Protection System:
Introduction to protection system and its elements, functions of protective relaying, protective zones, primary and backup protection, desirable qualities of protective relaying, basic terminology.
Relays:
Electromagnetic, attracted and induction type relays, thermal relay, gas actuated relay, design considerations of electromagnetic relay.
Unit-II: Relay Application and Characteristics:
Amplitude and phase comparators, over current relays, directional relays, distance relays, differential relay.
Static Relays: Comparison with electromagnetic relay, classification and their description, over current relays, directional relay, distance relays, differential relay.
Unit-III Protection of Transmission Line:
Over current protection, distance protection, pilot wire protection, carrier current protection, protection of bus, auto re-closing,
Unit-IV: Circuit Breaking:
Properties of arc, arc extinction theories, re-striking voltage transient, current chopping, resistance switching, capacitive current interruption, short line interruption, circuit breaker ratings.
Testing Of Circuit Breaker: Classification, testing station and equipments, testing procedure, direct and indirect testing.
Unit-V Apparatus Protection:
Protection of Transformer, generator and motor.
Circuit Breaker: Operating modes, selection of circuit breakers, constructional features and operation of Bulk Oil, Minimum Oil, Air Blast, SF6, Vacuum and d. c. circuit breakers.
This directional over current relay employs the principle of actuation of the relay....It has a metallic disc free to rotate between the poles of two...
Wide area monitoring systems (WAMS) are essentially based on the new data acquisition technology of phasor measurement and allow monitoring transmission system conditions over large areas in view of detecting and further counteracting grid instabilities.
POWER QUALITY IMPROVEMENT AND FAULT RIDE THROUGH OF GRID CONNECTED WIND ENE...Bharadwaj S
This work tries to improve the power quality by compensating reactive power with Active Power Filters and also to analyze Fault Ride Through of Grid connected wind energy conversion systems.
A power quality presentation includes definitions of power quality, most common power quality problems and the solutions, standard carves, and practical example of an active filter. Presented by - Eng. Shemy Elhady
About Transmission Line.
Transmission Lines
Classification Of Transmission Lines
Overhead Power Line
Advantages Of Overhead Transmission Lines
Disadvantages Of Overhead Transmission Lines
Nominal “T” Method
Nominal “Pi” Model of a Medium Transmission Line
Underground Transmission Lines
Classification Of Underground Cables
Advantages Of Underground Cables
Disadvantages Of Underground Cables
Unit I: Introduction to Protection System:
Introduction to protection system and its elements, functions of protective relaying, protective zones, primary and backup protection, desirable qualities of protective relaying, basic terminology.
Relays:
Electromagnetic, attracted and induction type relays, thermal relay, gas actuated relay, design considerations of electromagnetic relay.
Unit-II: Relay Application and Characteristics:
Amplitude and phase comparators, over current relays, directional relays, distance relays, differential relay.
Static Relays: Comparison with electromagnetic relay, classification and their description, over current relays, directional relay, distance relays, differential relay.
Unit-III Protection of Transmission Line:
Over current protection, distance protection, pilot wire protection, carrier current protection, protection of bus, auto re-closing,
Unit-IV: Circuit Breaking:
Properties of arc, arc extinction theories, re-striking voltage transient, current chopping, resistance switching, capacitive current interruption, short line interruption, circuit breaker ratings.
Testing Of Circuit Breaker: Classification, testing station and equipments, testing procedure, direct and indirect testing.
Unit-V Apparatus Protection:
Protection of Transformer, generator and motor.
Circuit Breaker: Operating modes, selection of circuit breakers, constructional features and operation of Bulk Oil, Minimum Oil, Air Blast, SF6, Vacuum and d. c. circuit breakers.
This directional over current relay employs the principle of actuation of the relay....It has a metallic disc free to rotate between the poles of two...
Wide area monitoring systems (WAMS) are essentially based on the new data acquisition technology of phasor measurement and allow monitoring transmission system conditions over large areas in view of detecting and further counteracting grid instabilities.
POWER QUALITY IMPROVEMENT AND FAULT RIDE THROUGH OF GRID CONNECTED WIND ENE...Bharadwaj S
This work tries to improve the power quality by compensating reactive power with Active Power Filters and also to analyze Fault Ride Through of Grid connected wind energy conversion systems.
A power quality presentation includes definitions of power quality, most common power quality problems and the solutions, standard carves, and practical example of an active filter. Presented by - Eng. Shemy Elhady
About Transmission Line.
Transmission Lines
Classification Of Transmission Lines
Overhead Power Line
Advantages Of Overhead Transmission Lines
Disadvantages Of Overhead Transmission Lines
Nominal “T” Method
Nominal “Pi” Model of a Medium Transmission Line
Underground Transmission Lines
Classification Of Underground Cables
Advantages Of Underground Cables
Disadvantages Of Underground Cables
Identification of Reactive Power Reserve in Transmission NetworkIDES Editor
The paper describes importance of the reactive
power control basing on the failures and control problems in
the Polish transmission networks. A detailed description of the
operational difficulties is provided. The paper also presents a
highly automated method identifying voltage control areas
(VCA), areas prone to voltage instability, and reactive power
reserves requirement ensuring voltage stability under all
considered contingencies. During the completion of the VCA
project testing of the VCA software was limited to power flow
models of the Polish Power Grid Operator (PSE) System. A
detailed description of the operational difficulties is provided.
Conclusions, repairs and prevention undertaking are also
described.
After a blackout
If a blackout (a near total loss of generation and load) takes place, efforts have to be taken to bring back the
system to a normal state at the earliest. It may surprise you to know that this (black starting!) is not an easy
task. We shall see why in this lecture.
Once a generator is tripped, restarting it requires a significant amount of power. Power is required for 2 types of
activities:
a) Survival Power: For emergency lighting, battery chargers etc. Usually the requirement is 0.3% of the
generator capacity.
b)
Startup Power: For starting power plant auxiliaries (pumps etc.) Interestingly, nuclear and thermal units
require approximately 8 % of the unit capacity for auxiliaries alone! Therefore, a 500 MW generator
requires approximately 40 MW for running its auxiliaries.
Hydro and Gas units, on the other hand, require only about 0.5-2% of unit capacity for auxiliaries and can be
started usually from in-house DG sets.
The major steps required for restoration are:
a) Islands which have survived need to be stabilised for frequency and need to be used for starting other
units
b) Hydro/Gas units which require less startup power need to be started using in-house DG sets.
c) Larger thermal units need to be fed "startup power" from: 1) Islands which have survived 2)
Blackstarted generators 3) Other synchronous grids (temporarily)
d) Started units are synchronised with one another.
e) Loads and Generation have to be matched as much as possible to avoid large frequency variations.
Governors have a major role in stabilizing frequency in an island.
SAP Sapphire 2024 - ASUG301 building better apps with SAP Fiori.pdfPeter Spielvogel
Building better applications for business users with SAP Fiori.
• What is SAP Fiori and why it matters to you
• How a better user experience drives measurable business benefits
• How to get started with SAP Fiori today
• How SAP Fiori elements accelerates application development
• How SAP Build Code includes SAP Fiori tools and other generative artificial intelligence capabilities
• How SAP Fiori paves the way for using AI in SAP apps
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
4. CERC report
CERC conducted an investigation on the causes
• Full report on grid disturbance (CERC Order in Petition No.
167/Suo-Motu/2012 dated 1st Aug2012).
• CERC released the report titled “Status of action taken on
recommendation of the enquiry committee on grid disturbance
in northern region on 30th July 2012 and in Northern, Eastern
& North-Eastern Region on 31st JULY 2012”
4
5. 2. India National Grid – Hierarchy
Indian Grid -
NLDC
Southern
New Grid Region - RLDC
Northern Western Eastern North-Eastern
SLDC
Region -RLDC Region - RLDC Region - RLDC Region - RLDC
SLDC SLDC SLDC SLDC
SLDC - State Load Dispatch Centre
5
6. Types of Transmission line
• Mostly within the state
220kV
• Long distance (State-State, Region – Region)
400kV
• Long distance state – Region- Region transmission
765kV
• Latest technology for long distance power transmission with minimum losses.
500 kV - • These are much popular in the off-shore wind farm transmission lines in the UK
HVDC
HVDC – High Voltage Direct Current
These systems use direct current for the bulk transmission of electrical power, in contrast with the more common
alternating current systems. For long-distance transmission, HVDC systems may be less expensive and suffer lower
electrical losses. 6
8. What is grid disturbance?
A grid is said to be
disturbed when :
f) there is a power a) there is an under
failure in the grid voltage (U/V)
e) there is a rapid fall
b) there is over
or rise in frequency (
voltage (O/V)
+dF/dT or -dF/dT )
d) there is over c) there is under
frequency (O/F) frequency (U/F)
8
10. 29th July – evening before blackout
The 400 kV Bina- Gwalior-Agra-
2 was under planned shutdown
since 28thJuly 2012 for up-
gradation work to 765kV.
At 10:18pm, 400 kV Zerda- 28th July 2012 At 3:15pm, 29th July - 220
Kankroli Emergency outage kV Kota-Badod Tripped due
for a period of two hours to to operation of distance
take out one Tool & Plant (T protection three phase
& P) which got stuck with Zone-1 indications at Badod
one polymer insulator. end.
10:18pm 3:15pm
At 3:40pm, 220 kV Binmal
9:45pm 3:40pm (PG)- Sirohi - Phase to earth
At 9:45pm, 400 kV Bhinmal-
fault. The two 220 kV
Kankroli Tripped due to
outlets to Bhinmal(RVPNL)
insulator de-capping.
and one to Sanchore were
in service from Bhinmal.
10
13. Reason for blackout -30th July 2012 Summary
400kV Bina-Gwalior-Agra 2
line was under planned
shutdown. This caused stress
Once almost all the 400kV on other lines. Failure in load
lines tripped overnight management and planning
(from WR to NR) and even
many 200kV lines tripped, Large amount of
now the power from WR unscheduled import of
started to flow to NR power by the Northern
though ER. This caused region from western and
power swings in the ER and eastern region.
more lines started tripping
and caused a complete
blackout. Action was not taken to
reduce the Total Transfer
Capability (TTC) after shut
Sipat stage-1 plant was down of Zerda-Kankroli 400
under trial operation and KV line, . The TTC is shown
caused unscheduled as 2000 MW before and
injection of power. after the shutdown of 400
KV line.
Some gas and thermal plants Lack of observation and
where tripped in NR due to coordination!
forced outage and shortage
of coal.
Irregular Maintenance and
lack of monitoring
13
15. Restoration – after blackout 30 th July
• The blackout happened exactly at time – 2.33am . This affected 8 states and 1
U.T (Rajasthan, Haryana, New Delhi, J&K, Punjab, U.P, Himachal Pradesh,
Uttarakhand and Chandigarh)
• Emergency loads like railway station, hospitals, airport were supplied with
power by 8am
• By 10am 40% of the loads where restored.
• 100% load was restored by 4pm evening the same day.
Following slides shows how the restoration process was carried out!
15
19. 4. 31ST July Blackout
• The Black out happened exactly at time – 1.00pm . This affected 21 states and
1 Union Territory. This caused much bigger effect than the 30th July Blackout.
• The following states were affected by the grid failure:
– States on the northern grid: Delhi, Haryana, Himachal Pradesh, Jammu &
Kashmir, Punjab, Rajasthan, Uttar Pradesh, Uttarakhand
– States on the eastern grid: Bihar, Jharkhand, Orissa, West Bengal
– States on the northeast grid: Arunanchal Pradesh, Assam, Manipur, Meghalaya,
Mizoram, Nagaland, Sikkim
• The worst sufferers were 265 miners who got trapped in coal mines in West
Bengal and Jharkhand due to the power outage. They were evacuated after
hours of agony.
19
21. Frequency shoot up at western region (WR)
In the Western Region due to loss of
export to rest of the NEW grid, the
frequency shot up to 51.46 Hz and
many generating units and
transmission lines tripped due to
process related issues and high
voltage respectively.
The frequency stabilized at around
51.0 Hz. The rise in frequency only
illustrates the poor level of
primary response.
21
22. Reason for blackout 31st July 2012 Summary
Loss of 400 kV Bina-Gwalior link: Similar
to the initiation of the disturbance on 30th
July, 2012, tripping of 400 kV Bina-Gwalior
line on zone-3 protection of distance relay,
due to load encroachment, caused the NR
system to separate from the WR system.
The UFR load shedding
was not adequate to bring Weak Inter-regional
the frequency back to a Corridors due to multiple
safer level of 49.5 Hz and outages
above.
Inadequate Response by
SLDCs to RLDCs’ High Loading on 400 kV
instructions on this day Bina-Gwalior-Agra link
also to reduce overdrawl by -NR utilized Unscheduled
the NR utilities and Interchange (UI) and this
underdrawal by the WR lead to overloading
utilities
22
23. Restoration after blackout -31st July
• Total affected load because of Blackout was 48,000MW
• Emergency loads like railway station, hospitals were supplied
with power by 3:30pm
• 100% load was restored by 9.30pm evening, the same day.
23
25. 5. Technical Recommendations -1
• Review protection schemes along with Immediate review of zone-3 philosophy
• Synchro-phasor measurements from PMUs should be explored for protection systems
• A complete independent audit of time synchronization of DRs, ELs and PMUs
• Frequency band tightening up close to 50 Hz
• Review of UI mechanism
• STUs should immediately enable under frequency and df/dt based load shedding schemes
• Faster algorithm for calculation of TTC.
• The regulatory provisions regarding absorption of reactive power by generating units needs
to be implemented
25
26. Technical Recommendations -2
• Installation of adequate static and dynamic reactive power compensators should be
planned.
• Functioning of existing PMUs and availability of their output to RLDCs and accuracy of time
synchronization should be monitored on daily basis and, if required, corrective actions should be
taken on priority basis.
• The Synchro-phasor based WAMS employing PMUs offer a wide applications for real time
monitoring and control of the system, specially under the dynamic conditions.
• Adequate number of PMUs should be installed to improve the visibility and real time
monitoring of the system.
• Possibility of voltage collapse prediction, sensing global power system conditions derived from
local measurements may be explored
26
27. Technical Recommendations -3
• Islands: Efforts should be made to design islanding scheme based on frequency
sensing relays so that in case of imminent grid failure, electrical islands can be
formed. This will also help in faster restoration of grid.
• The Communication network should be strengthened by putting fiber optic
communication system. Further, the Communication network should be
maintained properly to ensure reliability of data.
• UPS - RTUs and communication equipment should have uninterrupted power
supply with proper battery backup so that in case of total power failure,
supervisory control and data acquisition channels do not fail.
• Telemetry facility at all generating station and transmission liens – at the
earliest.
27
28. Technical Recommendations -4
• A standard procedure for preparatory activities and sequence of start up
may be put in place by the stations to restore units as early as possible
particularly in contingencies
• An audit of devices such as HVDC, TCSC, SVC and to ensure their
stability features are enabled.
• For smooth operation of grid systems, it is absolutely important that all the
power generating and distributing stations are connected on a very reliable
telecom network.
(i) A proper network may be built up preferably using MPLS (Multi Protocol Label
Switching)
(ii) IT network may be built using dedicated fibres to avoid any cyber attack on the
power system.
28
29. 6. Policy Recommendations-1
• Implementation of various regulations issued under the Electricity Act, 2003 and look
into violation SERIOUSLY.
• Real-time security desk in all the shifts to be manned by engineer capable of
carrying out TTC calculations (in NLDC and RLDC).
• LDC and Regulatory Commissions related to non-compliance of regulatory
provisions including that for noncompliance of directions and non-payment of UI
charges, need review.
• The present organizational set up of Load Dispatch Centres need to be reviewed.
• Training and certification of system operators need to be given focused attention.
29
30. Policy Recommendations-2
• There is need to reinforce system study groups in power sector organizations to
analyze the system behavior under different network status/ tripping of
lines/outage of generators. Where these do not exist, these should be created.
• Intra-State transmission system needs to be planned and strengthened in a better way
to avoid problems of frequent congestion
• Special task force - involving experts from academics, power utilities and system
operators, to carry out a detailed analysis of the present grid conditions and
anticipated scenarios which might lead to any such disturbances in future.
• Sufficient financial incentives need to be given to certified system operators so that
system operation gets recognized as specialized activity.
30
31. 7. Proposed protection study
• Phasor Measurement Units (PMU)
• These are highly sophisticated instruments to measure change in
Installation voltage/current in milliseconds.
of PMUs :
31
32. Relay Protection
• These connected on the transmission lines
• Distance relays will sense a fault/disturbance in the grid and give a trip command
Distance to the incomer breaker whenever the grid disturbance exceeds a set limit.
Relays: • By opening the incomer breaker, the plant/line is isolated from the grid.
• These perform mathematical algorithms and to offer very high accuracy &
resolution.
Numeric • These help in detection of dF/dT fault (change in frequency)
Relays:
32
33. Study of Zone 3 faulty tripping by DR
• Line Fault - Usually any fault in the zone 3 region due to phase-phase fault, phase-
ground or other faults will activate the distance relay to open the circuit (Circuit
Breaker – VCB/SF6-CB)
• Overloading - If there is overloading this will also create a low impedance on the
lines and lead to zone 3 fault alert. Before the far distance relays operate, the local
relays should sense this and the appropriate load shedding should be done.
• Failure - If failure of load shedding, the far distance relay operate and this leads to
blackout of the entire distribution lines. (This can be a major reason for 30,31st July
blackout, So proper considerations should be made for load characteristics)
Please find a example picture in the next slide.
33
35. Study of UFR /(dF/dT) under load encroachment
conditions
• What really happened – to the protective UFR and dF/dT relays? Why didn’t they
help in load shedding to improve the declining frequency in Northern region (NR and
ER during 31st) on 30th blackout.
• Similarly in the western region the frequency rose up to 51.4Hz, and none of the
generators units responded to this frequency hike.
• A separate study has been proposed by the authorities to study regarding the settings
of these relays and fix the issues associated.
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36. Study on effects of : TCSC and SVC
How these compensators affect
What is a compensator? the protection distance relay
operation?
• A compensator is used in transmission • The Distance Relays (DR) use
lines/grid/load for voltage stability, impedance measurement to determine
reducing net losses, limiting short circuit the presence of faults.
currents, damping power oscillations by
compensation of real and reactive • The capacitance cancels or compensates
power. some of the inductance of the line and
therefore the relay (DR) may perceive a
fault to be in its first zone when the fault
is actually in the second or third zone of
protection.
TCSC – Thyristor Controlled Series Capacitors
SVC – Static VAR Compensator
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38. 8. Why Smart Grids?
If you can measure it, you can manage it…
To improve efficient
Distribution
To maximize
Generation
cyber safety
To improve communication
between various LDS’
To monitor the loads and shed
loads when stress increase or
frequency decrease rapidly.
To avoid unscheduled transfer
of power and blackouts
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39. Smart Grid for India
BESCOM has
begun work on
its Rs 87-crore T&D
smart grid Losses
project in the >30%
City.
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40. Features of Smart Grids
• Smart Metering
• On line monitoring portal – with help of SCADA systems
• Home automation
Local Load level • Public charging stations – for electric cars/bikes
• Smart Distribution
• Load/demand management
• Energy Audit
T & D level • Smart protection controls
• Renewable energy source integration or Distributed Generation
Smart
Generation
Here are some slides on Smart Grid solution from GE
40
45. Distributed Power Generation
• Distributed Generation is nothing but Generation at site.
• The most popular source for distributed generation is solar PV
• Germany has the largest percentage mix of solar PV DG at LV level in their total
energy mix. Germany has also developed their own grid codes for LV generation and
grid connection (recent policy– reactive power control, using solar grid inverter).
Source: BELELECTRIC
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46. Distribution level voltage issues (LV)
• The voltage level at the end consumer side face voltage drop due to transmission
losses, line impedance (R+JXL) and increase in load.
source: GE
46
47. Pros and Cons of Distributed Generation
• Here the voltage level gets stabilized due to the feed in power from solar. This can greatly reduce
the stress and disturbance on transmission lines.
• This can also increase the voltage above a certain level when more solar generators are present
and the inverters are forced to trip (overvoltage). This is dangerous and can cause blackouts.
• In 2011, Germany came up with some modifications in their grid codes with reactive power
controlled solar inverters.
• Distributed Generation can reduce the overall T&D losses (from HV, MV, to distribution LV).
source: GE
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48. LV level frequency and voltage control
• Recently grid tie solar inverters come with intelligent active and reactive power control
to keep the LV grid voltage and frequency under control.
• As shown in the graph below , when the frequency exceed a certain limit - the active
power control comes into play and reduces the overall power output to stabilize the
local grid.
• Similarly when there is a voltage increase, the reactive power is absorbed by the GT
solar inverters and this stabilizes the output accordingly (check image down).
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49. Summary
• In this presentation we had a look at the various events, issues and recovery
process carried out before and after the 2012,July blackout.
• The recommendation from the committee was also discussed.
• Study on the various protection relays and fault tripping
• Study on effects of capacitor compensators (SVC, TCSC) on protection
relays
• Required changes for the future – Smart Grids (Smart metering,
communication and renewable energy / distribution generation)
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51. Reference and Credits
Concept papers:
TCSC FOR PROTECTION OF TRANSMISSION LINE
P.S.Chaudhari#i, P. P.Kulkarni#2, R.M.Holmukhe#3, Mrs.P.A.Kulkarni #4 #iScientist, DRDO, Pune, India, #2DRDO, Pune, India
#,,3,4 Bharati Vidyapeeth University College of Engineering, Pune, India.
Pictures and other data:
• PMU - http://www.qualitrolcorp.com/Products/Q_PMU9/18/36_Phasor_measurement_units_%28PMU%29/
• www.erlphase.com(http://www.erlphase.com/downloads/data_sheets/L_PRO_4000_line_protection_relay_ds.pdf)
• http://phasormeasurements.blogspot.in/
• Distributed Generation – BELELECTRIC
• Blackout picture: http://www.desismartgrid.com/2012/08/indian-power-grid-blackout-reasons-and-future-requirements/
Blackout official data:
• Full report on grid disturbance (CERC Order in Petition No. 167/Suo-Motu/2012 dated 1st Aug2012).
• Status of action taken on recommendation of the enquiry committee on grid disturbance in northern region on 30th July 2012
and in Northern, Eastern & North-Eastern Region on 31st July 2012.
Smart Grid:
• GE - http://www.gedigitalenergy.com/communications.htm
• GE - http://www.gedigitalenergy.com/multilin/catalog/Transmission.htm#prl
• L&T - http://www.larsentoubro.com/lntcorporate/ebg/html/grid_islanding.htm
• SMA
• BESCOM - http://www.deccanherald.com/content/288701/bescom-ropes-us-firm-smart.html
• Indian Smart Grid Task Force
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