An enumerative analysis of major power blackouts in Asian region in the last two decades

Power System represents an interconnected network, where generation, transmission and distribution of electrical energy takes place. They are complex systems constituting various components like synchronous generators, motors, transformers, circuit breakers, transmission lines etc. A power system is required to operate in a reliable manner, thus providing continuous power supply of good quality. This requires the power system to be stable. Blackouts can occur due to equipment failure, human errors, natural disasters, overloading / imbalance, cyber-attacks, lack of redundancy etc. When they act in a combined manner/ if one of those issues lead to the other issue, widespread and long - lasting blackouts happen. Severities of the blackouts depend on geographical extent, duration of its existence, financial repercussions, and initial services being broken, public safety. This paper discusses the major blackouts that have occurred in the Asian region, in the last two decades, along with their causes and consequences.


Introduction
Total power disruption; which is a complete loss of supply of electricity; that can occur anywhere unexpectedly; in a geographical area; is called as a Power blackout.If power outage becomes more severe; it results in a Power Blackout.Recovery of the power back to normal is usually quite a difficult task for the power stations and utilities; which depends on finding out the basic reason for the occurrence of the power blackout.The deadlines for the repair depending on the structure of the defaulted electrical grid [1].The causes for these blackouts could be many; like errors from human end; natural calamities; sudden failure of equipment; and more [2].Power blackouts may last from days to few months.Few factors on which the duration on which clearance of an occurred blackout depends are the reason for the blackout; the stretch or range of damage faced by the whole power framework; the quantity of assets which are available to be used in the process of repair; and the degree of efficiency of the emergency kickback techniques [3].When it comes to the consequences of blackouts; it can be really acute; that could result in endangered public safety; social disintegration; financial losses; human losses and influence of environment [1][4].These can rapidly and alarmingly affect the daily lives of innumerable people.Thus; it is very important to understand about power blackouts.Thus; it is mandatory to work towards keeping the power system stable; even when faults occur; by isolating the faulty component alone; hence allowing the healthy portion of the power system to operate.This will obviously help in preventing power blackout and cascaded failures [5]; [6] to [12].The Bina -Gwalior is connected by a 400 KV transmission line.At 2.35AM (IST); this line tripped.This line was feeding Agra -Bareilly transmission section.This caused breakers to trip; at the station.This resulted in cascaded power failures in the grid; leading to shut down of major power stations in the states; enlisting huge power shortage [13].This was assumed to be the worst of its kind in a decade [14].Airport in Delhi; the busiest one in South Asia ; was able to continue its functioning; with the help of back -up power; in 15 seconds [15].Traffic signals did not work.Passenger train operation was ceased [13].Many hospital services were interfered; while few carried on with back-up generators [14].Operation of water treatment plants stopped for hours [16].People were unable to draw well water due to nonavailability of electrical supply to pumps [17].According to PGCIL (Power Grid Corporation of India Ltd) and NRLDC (Northern Regional Load Dispatch Centre); Uttar Pradesh; Haryana and Punjab were involved in overdraw.ASSOCHAM (Associated Chambers of Comers and Industry of India); declared that the blackout severely impacted businesses [18].80% of service restoration took about15 hours [14].Power company reported that A fairly large breakdown that exposed major technical faults in India's grid system.Something went terribly wrong which caused the backup safety systems to fail.[19]  This occurred in accordance of problem in area near Taj Mahal [19].The system again failed at 13.02 IST; resulting in affected parts of the power systems of India going offline.NTPCL terminated 38% of generation capacity [20].People were without power in 22 states out of 28 ones in India [21].The northern; north central; east central and east coast railway zones were the most badly affected ones; due to the collapse of power grid [16].About 200 miners who got trapped underground; in eastern India were found and rescued later.This occurred due to the failure of lifts [22].In the Northern grid-Delhi; Haryana; Himachal Pradesh; Jammu and Kashmir; Punjab; Rajasthan; Uttar Pradesh and Uttarakhand; were the affected.In Eastern grid-Bihar; Jharkhand; Odisha; West Bengal; and Sikkim were affected.In North-eastern grid-Arunachal Pradesh; Assam; Manipur; Meghalaya; Mizoram; Nagaland and Tripura were affected [23].The day the collapse occurred; initiatives were taken to ascertain the cause of failure; to be reported in a timeline of 15 days [24].It was found that four factors lead to this power blackout as found by the investigation committee.They are Multiple scheduled and forced outages; lead to weakening of inter-regional power transmission corridors.On Bina-Gwalior-Agra link; a high loading of 400KVA was spotted.Directives were given by RLDCs; to reduce over -drawing by utilities in the northern region; and under -drawing or excess generation in western region.These were not properly incorporated by SLDCs.Due to malfunctioning of the protection system; the Bina-Gwalior-Agra link was lost.Committee suggested a number of counsels to escape failures in future.It also stressed the need for audit of protection systems [25].

Pakistan blackout-2023
This event is a Nationwide outage of power that occurred in Pakistan on 23rd January 2023 at 7.34 AM [26].The blackout lasted for more than12 hours; while even longer in some areas.It is listed as the 2nd major grid crash in the last 2 years [27].This occurred due to sudden drop in frequency of power transmission system; due to voltage fluctuation between Jamshoro and Dadu cities [28].It resulted in an extensive blackout.The affected regions were found to be Islamabad; Karachi; Lahore; Peshawar; Quetta and; and also many small cities and towns [29].Post the breakdown; more than 220 million people were hurled into darkness; in Pakistan.Hospitals informed that they managed by switching back-up generators; though interruptions continued.Internet services and mobile networks were affected.People lost access to withdraw money due to non-working of ATM's; because of non-availability of back-up power [30].
Textile industry lost 70 million dollars [31]. Water pumps also failed.Electricity infrastructure of Pakistan is quite delicate and complex.So; the issue in one portion of the grid would lead to collapse across the entire network.Energy shortages are also common leading to recurrent power outages.

Bangladesh blackout-2022
On 4th October 2022; this power blackout had occurred throughout Bangladesh [40].This situation had prolonged for about 7 hours [41].Defective operation of the country's power grid around 2PM; resulted in this power blackout; as claimed by Bangladesh Power Board [42].Power supply was broken in Dhaka and many huge cities; as the power plant stumbled [43].The functioning of export -based garment industry was impaired in Bangladesh due to this power blackout.In this situation; as generator's ability to work was poor; Bangladesh Garment Manufacturers and export Association; had to close their offices [44].

Interpretations
Cascaded events cause the electrical distance between generator and loads to increase; thus tripping the major transmission lines.This resulted in divergence of load angles of generators and insufficient coupling between the generating systems due to synchronizing power lag.When there is greater angle difference between two regions; the line between them will be sluggish with low voltage [45].Thus; while operating the power system; it is vital to maintain flat voltage profile; which provides great security [46].Most of the blackouts were found to have occurred due to voltage collapse conditions.

Conclusion
The present power status in India is a struggle and needs to be handled with care.The generated power supply seems to be much less than the demand that has to be met; which obviously results in shortage of power in industries in the country.Power blackouts are mostly a cause of sequence of events instead of one single issue.Still it is very much necessary to search that one single issue that commenced the entire process.Once the prior history of major and correctly reported power blackouts in the Asian countries is discussed and analyzed; that provides the required learning.This would positively help to assess and prevent blackouts and also provides knowledge to handle them during occurrence of power blackouts.

Table 1
Details of power blackouts in Asian region

Table 2
Details of power blackout in India on 30 July 2012

Table 3
Details of power blackout in India on 31 July 2012

Table 4
Details of power blackout in Pakistan on 23 rd January 2023 This power blackout occurred on 2ndJanuary 2001; in India.Poor and in adequate transmission equipment; causing substation failure in Uttar Pradesh; was the trigger to this power blackout.This caused crashing of northern grid.It affected almost 230 million people in north India; who depended for power supply from this second biggest interconnected network in the country.This interrupted the railway services too[32].It lasted for16 to 20 hours.The loss was calculated to be approximately 5 billion rupees.

Table 5
[38]ils of power blackout in India on 2 nd January 2001This blackout occurred on 9th January; 2021[33][34]; at 11.41 PM; local time.The outage was triggered by An Engineering Fault; in Guddu Power Plant in South Pakistan.This resulted in tripping of system and eventually the close down of the entire system [35][36].Major cities like Karachi; Multan; Lahore; Rawalpindi; Peshawar; Quetta; Narowal; Bahawalpur and also the capital Islamabad[37].80%to90% of power was disconnected[38].A fine of 50 million rupees was thrust on National Transmission and Dispatch Company (NTDC) by National Electric Power regulatory Authority (NEPRA); post an enquiry on this incident.The fine was found to be imposed due to improper provision of electricity supply[39].

Table 6
Details of power blackout in Pakistan on 9 th January 2021

Table 7
Details of power blackout in Bangladesh on 4 th October 2022