Module 6 : Preventive, Emergency and Restorative Control
Lecture 30 : A Blackout !
Objectives
In this lecture you will learn the following
Definition of blackouts and their occurences.
A detailed description of the January 2001 Collapse of Northern Regional Grid of India
When can a blackout occur ?
In the previous lecture we saw how a system can go from an alert state to an emergency state because of
equipment limit violations or instability. The first line of defence against these undesirable transients is to carry
out static and dynamic security analysis (using computer simulations) in order to check the system behaviour
under different contingency situations (if they were to occur). Preventive Control actions ensure that any such
contingency (if it occurs) does not lead to equipment limit violation or instability.
Emergency control actions come into play if an actual disturbance takes place and is evolving into an
equipment limit violation or instability, or both. These actions try to prevent an emergency situation from
deteriorating into a near-complete loss of generation and load (a blackout !).
Inspite of security analysis and preventive actions (done during actual operation), and emergency control
actions (usually pre-designed offline), blackouts do occur. It should be understood that because of the large
number and diversity of equipment in a power system, every disturbance and contingency scenario cannot be
anticipated . Moreover there may be mal-operation of protective equipment and relays.
Therefore, blackouts have occured from time to time in the world. In this lecture we describe a real life event -
the January 2001 blackout of the northern regional grid of India.
The January 2001 collapse of the Northern Regional Grid of India
North India enters new millennium shivering in the dark (Indian Express, Wednesday, January 3, 2001)
NEW DELHI, JANUARY 2: Virtually the entire northern India, from Jammu and Kashmir to Uttar Pradesh, faced
its worst ever blackout in the last five years as seven states went without power for nearly sixteen hours since
around four in the morning on Tuesday.....
Overview of the Northern Regional Grid (adapted from the REPORT OF THE COMMITTEE ON GRID DISTURBANCE
IN NORTHERN REGION ON 2ND JANUARY, 2001 authored by V.V.R.K.Rao & R.N.Srivastava -
http://powermin.nic.in/reports/report_disturbance_northern_rg.htm, and the text of the submission by Power
Grid Corporation of India Ltd (PGCIL) before the Central Electricity Regulatory Commission on 15-1-2001)
Northern Regional Grid is the 2nd largest inter-connected network (synchronous grid) in the country. As on 1st
January, 2001 Northern Regional Power System had an Installed capacity of 27042 MW comprising of 8311 MW
Hydro (31%), 17597 MW thermal (including GT and Diesel plants) (65%), and 1130 MW Nuclear (4.0%) and
balance 4 MW wind. The share of state sector (16190 MW) and central sector (10852 MW) in the total capacity
was 60% and 40%. The Region has a hydro-thermal mix of 31:69.During the period up to December, 2000, the
Northern Region had been facing peak shortage of 10% and energy shortage of about 6%. Against a
requirement of 98 billion units of energy, the actual met had been about 92 billion units. The peak demand met
was of the order of 19860 MW against a restricted peak demand of 21740 MW. The shortages vary from month
to month.
The Northern Regional Power System has major thermal power stations located at the coal based pit heads at
Singrauli, Rihand, Obra and Anpara. The Region has major hydro electric power stations located in the
Himalayan belt, such as Bhakra, Dehar, Pong, Chamera, Baira-Siul and Salal, Uri and the hydro power stations
in the Yamuna region of UP. A number of thermal power Stations are also located near the load centres, such as
, Tanda, Unchahar, Panki, Dadri, Parichha, Harduaganj, Badarpur, Indraprastha, Rajghat, Panipat, Ropar,
Bhatinda, Suratgarh and Kota and also the Rajasthan and Narora Atomic Power Stations. Also the Region
includes Gas Turbine Power Stations at Auraiya, Anta, Dadri, Indraprastha and Srinagar.
The large coal pit head thermal power stations are located in the extreme South-Eastern part of the Regional
grid. Therefore, there is a large flow of power from the South-Eastern part to the Central and Western parts of
the grid round the year. During winter months when the flows dwindle to their annual minimum value, many of
hydro stations are shut down during night off peak hours. To handle the bulk transmission of power, a point-to-
point high voltage direct current link, viz. ± 500 kV HVDC Rihand-Dadri bipole with a capacity of 1500 MW has
been established which operates in parallel with an extensive 400 kV A.C. transmission system and the
underlying 220 kV network. There also exists a high voltage 500 MW capacity back-to-back DC link between
Singrauli in Northern Region and Vindhyachal in the Western Region over which power exchanges are carried out
between the two regions. A 2x140 MVAR SVC (Static Var Compensator) is also provided at 400 kV substation at
Kanpur which helps in improving the stability of the system. For a grid diagram of the system, view the same
below (courtesy NRLDC website : www.nrldc.org).
(the above maps can also be viewed from this site :
http://nrldc.org/nrldc/powermaps.asp)
(Click on the Maps to enlarge)
Lecture 30 : A Blackout !
Objectives
In this lecture you will learn the following
Definition of blackouts and their occurences.
A detailed description of the January 2001 Collapse of Northern Regional Grid of India
When can a blackout occur ?
In the previous lecture we saw how a system can go from an alert state to an emergency state because of
equipment limit violations or instability. The first line of defence against these undesirable transients is to carry
out static and dynamic security analysis (using computer simulations) in order to check the system behaviour
under different contingency situations (if they were to occur). Preventive Control actions ensure that any such
contingency (if it occurs) does not lead to equipment limit violation or instability.
Emergency control actions come into play if an actual disturbance takes place and is evolving into an
equipment limit violation or instability, or both. These actions try to prevent an emergency situation from
deteriorating into a near-complete loss of generation and load (a blackout !).
Inspite of security analysis and preventive actions (done during actual operation), and emergency control
actions (usually pre-designed offline), blackouts do occur. It should be understood that because of the large
number and diversity of equipment in a power system, every disturbance and contingency scenario cannot be
anticipated . Moreover there may be mal-operation of protective equipment and relays.
Therefore, blackouts have occured from time to time in the world. In this lecture we describe a real life event -
the January 2001 blackout of the northern regional grid of India.
The January 2001 collapse of the Northern Regional Grid of India
North India enters new millennium shivering in the dark (Indian Express, Wednesday, January 3, 2001)
NEW DELHI, JANUARY 2: Virtually the entire northern India, from Jammu and Kashmir to Uttar Pradesh, faced
its worst ever blackout in the last five years as seven states went without power for nearly sixteen hours since
around four in the morning on Tuesday.....
Overview of the Northern Regional Grid (adapted from the REPORT OF THE COMMITTEE ON GRID DISTURBANCE
IN NORTHERN REGION ON 2ND JANUARY, 2001 authored by V.V.R.K.Rao & R.N.Srivastava -
http://powermin.nic.in/reports/report_disturbance_northern_rg.htm, and the text of the submission by Power
Grid Corporation of India Ltd (PGCIL) before the Central Electricity Regulatory Commission on 15-1-2001)
Northern Regional Grid is the 2nd largest inter-connected network (synchronous grid) in the country. As on 1st
January, 2001 Northern Regional Power System had an Installed capacity of 27042 MW comprising of 8311 MW
Hydro (31%), 17597 MW thermal (including GT and Diesel plants) (65%), and 1130 MW Nuclear (4.0%) and
balance 4 MW wind. The share of state sector (16190 MW) and central sector (10852 MW) in the total capacity
was 60% and 40%. The Region has a hydro-thermal mix of 31:69.During the period up to December, 2000, the
Northern Region had been facing peak shortage of 10% and energy shortage of about 6%. Against a
requirement of 98 billion units of energy, the actual met had been about 92 billion units. The peak demand met
was of the order of 19860 MW against a restricted peak demand of 21740 MW. The shortages vary from month
to month.
The Northern Regional Power System has major thermal power stations located at the coal based pit heads at
Singrauli, Rihand, Obra and Anpara. The Region has major hydro electric power stations located in the
Himalayan belt, such as Bhakra, Dehar, Pong, Chamera, Baira-Siul and Salal, Uri and the hydro power stations
in the Yamuna region of UP. A number of thermal power Stations are also located near the load centres, such as
, Tanda, Unchahar, Panki, Dadri, Parichha, Harduaganj, Badarpur, Indraprastha, Rajghat, Panipat, Ropar,
Bhatinda, Suratgarh and Kota and also the Rajasthan and Narora Atomic Power Stations. Also the Region
includes Gas Turbine Power Stations at Auraiya, Anta, Dadri, Indraprastha and Srinagar.
The large coal pit head thermal power stations are located in the extreme South-Eastern part of the Regional
grid. Therefore, there is a large flow of power from the South-Eastern part to the Central and Western parts of
the grid round the year. During winter months when the flows dwindle to their annual minimum value, many of
hydro stations are shut down during night off peak hours. To handle the bulk transmission of power, a point-to-
point high voltage direct current link, viz. ± 500 kV HVDC Rihand-Dadri bipole with a capacity of 1500 MW has
been established which operates in parallel with an extensive 400 kV A.C. transmission system and the
underlying 220 kV network. There also exists a high voltage 500 MW capacity back-to-back DC link between
Singrauli in Northern Region and Vindhyachal in the Western Region over which power exchanges are carried out
between the two regions. A 2x140 MVAR SVC (Static Var Compensator) is also provided at 400 kV substation at
Kanpur which helps in improving the stability of the system. For a grid diagram of the system, view the same
below (courtesy NRLDC website : www.nrldc.org).
(the above maps can also be viewed from this site :
http://nrldc.org/nrldc/powermaps.asp)
(Click on the Maps to enlarge)
