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Cover Story | April 2017

Blackouts under control

We could avoid blackouts for four years does not mean that our grid infrastructure is robust. Implementation of plans at state level has to be expedited to yield better results.

Just think of power going off while an important surgery is taking place in a hospital and it will not get back for a day or two. The kind of disruption an electricity blackout arising from grid collapse can cause is enormous for different people at various places. Grid collapse is the worst-case scenario for any transmission utility too. If this happens, states that draw power from that particular network face veritable 'darkness' socially and economically.

Two consecutive days of grid collapse has left almost half of India's population without power in July 2012. Three out of five major grids - northern, north-eastern and eastern - have crashed. Over 20 states have reportedly been affected. Trains have been stalled, markets have closed down, and institutions and offices have been forced to announce holidays. This was nothing short of a 'manmade' national calamity that brought economic activity to a grinding halt.

This has come as a wake-up call for the Indian government reminding it of the urgency to upgrade the grid mechanism in the country through latest technologies and processes. India has five regional grids - northern, southern, eastern, north-eastern and western and all are connected.

Soon it became apparent that the failures were due to a combination of a variety of shortcomings in the power sector, though mainly because of a lack of grid discipline at state level - not sticking to the amount of power it needed and resorting to overdrawing, and the inability of the grid to break such states (particularly Uttar Pradesh or UP) from the network in time, resulting in grid collapse.

The tripping of lines and minor grid disturbances in regional grids had come down significantly over the years since 2012 collapse. However, these are clearly on the rise in the quarter ended December 2016, if one were to study POSOCO reports.

Reasons
Though the overarching reason that triggered the grid crash was overdrawal of power by UP without notice, it exposed the vulnerability of the grid at various levels.

'The real problem was, that was the time Western region had very good generating trends. But that was also the time wind power was generating at the maximum. The demand in the region was very low. Whereas it was paddy season in the north, and they wanted to draw more power. During the same time, Power Grid Corporation of India Ltd (PGCIL) has taken up the Bina-Gwaliar-Agra II line for maintenance, so it did not have sufficient capacity to transmit. That lead to the crash,' says Dr Pramod Deo, who was the Chairman of the Central Electricity Regulatory Commission (CERC) in 2012, when the grid collapse took place. He has retired in 2013.

When CERC was hearing the matter SLDCs of both Maharsahtra and Gujarat said they had nothing to do with it as wind power is a must use form, and cannot be stopped. 'The simple thing they should have done is to ask their thermal plants to shut down. They should not have been simply looking at the frequency, though it is one of the important parameters. Even as the NLDC (National Load Despatch Centre) and Western Region LDC had given enough signals that there is not enough corridor available, they had ignored it. That is what happens when they are fixated with one parameter. That is the real reason why it happened,' Deo added.

At the time of grid collapse, the sector was suffering from a peak load deficit of 15,000 MW and the states were eager to draw more power than what was allocated to them, according to the Centre for Science and Environment (CSE). Hydropower plants were running at lower capacity due to drought. And the states did not have a mechanism to limit their power drawal at the specified limits.

Executives of the power distribution companies (discoms) of UP, Punjab, Haryana, Rajasthan, Himachal Pradesh and Jammu and Kashmir, who had been summoned by CERC for hearing, said that political pressure was there for withdrawing more than their allotted share of electricity. Even turning a blind eye to overdrawals by some states was the result of a 'political decision', according to media reports in 2012.

Frequency
The penal provisions are applied based on frequency. (See the list of steps taken after 2012 grid collapse to improve grid discipline in the in-box) As a measure of tightening grid discipline and putting a check on over- or under-drawals, the frequency band was tightened from 49.5-50.2 Hz to 49.7-50.2 Hz, which was further revised in January 2014 to 49.9- 50.05Hz. Any deviation in adherence to the frequency bands will attract penal provisions.

POSOCO also studies Frequency Response Characteristics (FRC). FRC is a measure of the change in frequency to a given mismatch in load and generation. Frequency response in an electric power system is essentially provided by natural reduction of loads with frequency (also called as load damping) and primary response of generators. The importance of primary response has been brought out in clause 5.2 of the CERC (Indian Electricity Grid Code) Regulations, 2010. Primary response is of quintessential importance for maintaining the system security in light of integration of renewable generation, interconnection of neighbouring countries, impact of frequency variation on line flows and voltages, avoidance of large fluctuations in frequency and for restoration during Disturbances and Islanding.

POSOCO has identified five events of FRCs during the quarter ending December 2016, resulting in the total generation loss of 5,450 MW, load loss of 1500 MW and load shedding of 930 MW.

Penal provisions
Brought in to arrest or taper deviations, Indian Electricity Grid Code Regulations, 2010 (IEGC 2010), along with four amendments as well as State Grid Code, provide various provisions to maintain grid discipline. The penal provisions for overdrawing power from the grid are as per provisions of the IEGC and/or directions issued by RLDCs under Sections 29, 142 & 143 of the Electricity Act, 2003.

The CERC (Deviation Settlement Mechanism) Regulations 2014, itself provides for provisions with respect to schedule deviation beyond the permissible frequency band. These regulations were further amended to include the definition of error by drawing and generating entities against their schedule to let respective load despatch agencies initiate necessary action to contain such behaviour. The regulation now not only includes charges for deviation at frequency linked rate, but also introduces additional surcharge for deviations with narrow frequency band.

If any LDC observes such behaviour consistently, then it may approach CERC for seeking direction against the errant drawing or generating entities against the regulatory non-compliance.

In the backdrop of increased power supply demands, maintaining grid discipline is a big challenge, and the safety of power grid is the responsibility of all member institutions of each region.

Technology
To track these deviations indulged in by various stakeholders in the regional LDCs and at the national level, there have been several steps taken 'to enhance the technology available to visualize the status of the grid as well as automatic grid islanding and system protection schemes at various levels of system operations at the SLDCs, RLDCs and NLDC to ensure that there is quick reaction to any instability in the grid,' said the spokesperson of India Power Corporation Limited (IPCL).

'Technical systems which include real time despatch, frequency meters, supervisory control and data acquisition system (SCADA), energy management system, etc., were deployed at load centres to monitor the frequency of power, at a given time,' says Deo.

Measures such as frequency-based automatic load shedding schemes, system protection schemes, primary response from generators through Free Governor / Restricted Governor mode of operation are, at present, in place to prevent grid outages and power swings. Further, RLDCs and SLDCs also keep a watch on the overloading of grid elements even under normal frequency band of operation and advice the concerned utility to check the overloading which may lead to grid outages/power swings.

Grid incidents
In the October-December 2016, the latest quarter for which the details of grid incidents and grid disturbances are available, the overall events under these two parameters went up to 177, from 141 during the same quarter the previous year, reflecting that the instances of grid failures are on the rise year-on-year. Instances of grid anomalies rose in case of Northern, Southern and North-Eastern regions, while such instances fell in Western and Eastern regions. (See Table)

In the quarter ending December 2016, the overall number of grid disturbances of the first category (when less than 10 per cent of the antecedent generation or load in a regional grid is lost) have come down to 80 from 94 during the same quarter the previous year. Except for the Northern region grid, where the disturbances went up to 23 during the quarter from 17 the previous year, all other regions witnessed fall in such disturbances. There were no disturbances reported in the other four categories of higher consequences as it did during the same quarter the previous year.

As far as grid incidents are concerned, the overall number of grid incidents of the first category involving tripping of one or more power system elements of the grid at 220kV grid level went up steeply to 26 incidents from the meagre 7 in the previous year's quarter. In this category, Western, Southern and North-Eastern regions witnessed steep rise in the number of incidents occurred.

In the second category involving grid levels of 400 kV and above also the overall incidents have gone up to 70 from 40 the previous year. In this category, incidents in Northern, Southern and North-Eastern regions rose, while that of Western region they fell.

Deo feels that the recent spurt in demand for power was due to impending elections (in 5 states held in January-March 2017). 'When you have elections, you want to give more electricity. And you cannot buy electricity on the exchanges at that low rate. One of the other things you do is to overdraw. If you overdraw you have to pay penalty and that comes calling later.

That is the reason the problem started coming up recently.'

Tariffs
If states want to improve supply they have to buy electricity. They do not want to buy through long term PPAs also. Instead they pay average capacity charge and do not buy. And they buy it on the exchanges, where the price is hovering around `2-2.3 per kWh due to excess supply. 'That is the real problem we have,' says Deo.

'If they buy electricity as they have signed PPAs, they have to go for tariff revision. So instead of going for tariff revision, they go for load shedding,' Deo added.

Even the discoms are suffering losses due to under-charging for agriculture use, if one has to go by experiences of Maharashtra and Gujarat. While the cost of supply is at `6.50 per unit, the per unit charges for agriculture is `3.40/ unit. For the first time for agriculture they have increased it further from `3.10 to `3.40 in Maharashtra. Besides the government gives direct subsidy to farmers, which brings down the user charges to `1.20, Deo explains. In Gujarat it is even worse, at `2.46 they are contributing only 45 per cent of the cost.

In some states Punjab and Tamil Nadu power supply is free to the agriculture sector. Rajasthan has not revised the prices for many years, they have done it now. Chandrababu Naidu has raised the prices in the erstwhile united Andhra Pradesh (AP), and lost the election in 2004. After that even AP is wary of raising power prices. 'If something is used then somebody has to pay for the same,' Deo points out.

Renewables
The entry of renewable sources like solar and wind energy is set to change the dynamics of grid management, with their nature of intermittence. Already, the transmission system in India is one of the largest interconnected transmission systems in the world. There are scores of entities either injecting or drawing power from the grid at all times. As renewable sources are connected to the grid, these sellers and buyers will double the complexity in terms of numbers.

'And wind and solar are not like thermal power stations generating at commercial level. This will be according to the forecasting and scheduling, that have been made mandatory. For that CERC has also come out with deviation settlement mechanism (DSM), and the Forum of Regulators (FOR) has also prepared a model regulation. The states have to adopt these regulations in true spirit and that they are not doing. That is also going to create great problems,' says Deo.

Power grid has taken up development of green corridor to enable physical transfer of renewable power, and that will take some time.

'Gone are the days when NTPC plants were running at 90-95 per cent capacity. Now they are running at 55 per cent. Many of the thermal power plants now have to back down. CERC has come up with new regulation. This has kind of created volatility. That is the diverse situation you are facing,' says former CERC chairman.

Looking ahead
Transmission has been the weakest link of the Indian power sector. The 2012 grid collapse has highlighted the problem immensely. The whole transmission mechanism has to gear up for induction and supply of power on a large scale from renewable sources like solar and wind in the next couple of years.

Though the Centre seems to do everything to set the modern grid systems in place, one should not forget that power is a state subject, and it is they who have to implement the reforms in letter and spirit and raise tariffs to ensure that the discoms are not the losers in the business.

'The various measures taken so far have resulted in avoidance of any major grid failure and improving grid discipline. Most of the time, the frequency is being maintained within the limits,' says former CERC chairman.

There is a significant role for three critical factors, namely - policy and regulatory measures, market mechanics as well as technology - in ensuring that grid participating entities with load-generation balance responsibilities are able to manage temporal deviations smoothly by addressing load and generation imbalances quickly and effectively,' said IPCL spokesperson.

Enforcement without political inclinations has a critical role, it should be a non-negotiable policy.

For maintaining grid stability, the policy and regulatory measures taken including implementation of the Availabilty Based Tariff (ABT) mechanism as also the Deviation Settlement Mechanism (DSM) and Unscheduled Interchange (UI) mechanism have had a huge role to play in creating a self-correcting frequency balancing system. Work on these systems should be taken up on a war footing.

PGCIL, the grid monopoly till a few years back, has also taken up installation of static var compensator (SVC) that would help improve the electricity flow by controlling high-voltage electricity transmission networks, in its technical push.

NGOs like Prayas are doing a yeoman service to the power sector too. The government should help it to scale up the project through which it has introduced a device to study power quality at various levels to improve the real standard of living of the people by increasing the access of quality power and its benefits to common man. Ultimately, the government should ensure that the common man is not short circuited.

Steps taken to improve Grid Discipline since 2012 blackout
After the massive grid failure occurred on 30-31 July 2012, the Grid Disturbance Enquiry Committee headed by Chairperson, Central Electricity Authority (CEA) made a number of recommendations to prevent future recurrence of such grid disturbances. The Ministry of Power has taken numerous steps for implementation of the recommendations.

These, inter alia, include:

  • Tightening of frequency band from 49.5-50.2 Hz to 49.7-50.2 Hz, which was further revised in January 2014 to 49.9- 50.05Hz
  • Introduction of congestion charges in events of line outages by State Transmission units (STUs)
  • Control of unscheduled drawal. (Existing limit is 12% of schedule or 150 MW, for RE rich states it is 200 and 250 MW)
  • Independent third party protection audit.
  • Corrective action by PGCIL to renovate and upgrade their system.
  • Installation of optic-fibre network between all substations of PGCIL for advanced real time communication.
  • Preparation of Islanding Schemes in different states for sustained supply in emergency.
  • Revision of Transmission Planning Criteria (TPC).
  • Coordinated outage planning of inter-state and inter-regional transmission elements.
  • Introduction of frequency control through governor mode of operation by the generating companies.
  • Introduction of ancillary services for frequency control and voltage management.
  • To maintain strict grid discipline, Regional Load Dispatch Centres (RLDC) take action in accordance with Electricity Act, 2003 and the Indian Electricity Grid Code (IEGC) for supervision and control over Inter-State Transmission System (ISTS).
  • Action is initiated by CERC under Sections 142 & 143 of the Electricity Act, 2003 against the states violating the grid discipline.

  • In the matter of calculation of Total Transfer Capability (TTC), Available Transfer Capability (ATC) and Transmission Reliability Margin (TRM), CERC, in 2013, further directed CEA to constitute a National Reliability Council, with participation from CTU, CEA, RPCs/ State Representatives and IITs, which shall approve computation of TTC of various transmission corridors for the month, for the purpose of reliable operation of the grid. Accordingly, NRC for Electricity was in 2014, which looks into all aspects of reliability of the National Grid.
(Source: Dr Pramod Deo, Former Chairman, CERC)

''Post-2012 measures avoided major grid failures''
With the present grid control system, is there any guarantee now that the states do not over-draw and put the entire distribution system in peril? Are there more measures in the offing?
It is observed that the various measures discussed above have resulted in avoidance of any major grid failure and improving grid discipline. Most of the time, the frequency is being maintained within the limits.

However, following measures are under discussions at various fora for further improving the grid discipline:

a.The FOR has come up with SAMAST report which recommends the roadmap for
i. Deployment and implementation of framework on forecasting, scheduling and deviation settlement of wind and solar generating stations at the state level
ii. Introduction/implementation of Availability Based Tariff (ABT) framework at the State level as mandated in the National Electricity Policy and Tariff Policy
iii. Introduction of Ancillary Services and Reserves at the state level iv. Implementation of automatic generation and primary control within states
b.Model Forecasting and Scheduling (F&S) Framework for Wind and Solar at state level has been published by FOR
c.Preparation of Model Deviation Settlement Mechanism (DSM) Regulations for states is in process.
Implementation of these frameworks at state level will further improve the grid discipline and facilitate injection of RE power in the grid.

India has witnessed a massive power grid failure in July-August 2012 due to overdrawing by some states. What are the steps taken from then on to improve Grid Discipline?
The massive grid failure occurred on 30-31 July, 2012. The Grid Disturbance Enquiry Committee headed by Chairperson, CEA made number of recommendations to prevent future recurrence of such grid disturbances. The Ministry of Power has taken a number of steps for implementation of the recommendations of the Enquiry Committee.

These inter- alia, include:

  • Tightening of frequency band from 49.5-50.2 Hz to 49.7-50.2 Hz. (Further revised in January 2014. Existing frequency band is 49.9- 50.05Hz)
  • Introduction of congestion charges in events of line outages by STUs
  • Control of unscheduled drawal. (Existing limit is 12% of schedule or 150 MW, for RE rich states it is 200 and 250 MW)
  • Independent third party protection audit.
  • Corrective action by PGCIL to renovate and upgrade their system.
  • Installation of optic-fibre network between all substations of PGCIL for advanced real time communication.
  • Preparation of Islanding Schemes in different states for sustained supply in emergency.
  • Revision of Transmission Planning Criteria (TPC).
  • Coordinated outage planning of inter-state and inter-regional transmission elements.
  • Introduction of frequency control through governor mode of operation by the generating companies.
  • Introduction of ancillary services for frequency control and voltage management.
  • To maintain strict grid discipline, Regional Load Dispatch Centres (RLDC) take action in accordance with Electricity Act, 2003 and the Indian Electricity Grid Code (IEGC) for supervision and control over Inter-State Transmission System (ISTS).
  • Action is initiated by Central Electricity Regulatory Commission (CERC) under Sections 142 & 143 of the Electricity Act, 2003 against the states violating the grid discipline.
  • Further CERC, vide its Order dated 11.12.2013 in the matter of calculation of Total Transfer Capability (TTC), Available Transfer Capability (ATC) and Transmission Reliability Margin (TRM) directed CEA to constitute a National Reliability Council, with participation from CTU, CEA, RPCs/ State Representatives and IITs, which shall approve computation of TTC of various Transmission corridors for the month, for the purpose of reliable operation of the grid. Accordingly, National Reliability Council for Electricity was constituted on 21.2.2014, which looks in to all aspects of reliability of the National Grid.

What is the outcome of implementation of penalties and other provisions? Data on violations and imposed penalties along with State-wise data is available.
Indian Electricity Grid Code Regulations, 2010 (IEGC 2010) along with four amendments as well as State Grid Code provide the various provisions to maintain grid discipline. The penal provisions for overdrawing power from the grid are as per provisions of the IEGC and/or directions issued by RLDCs under Sections 29, 142 & 143 of the Electricity Act, 2003.

The details of penalties imposed by CERC during last 3 years 2009 to 2012 and the penalty deposited by erring power companies of the Northern Region are as under:
Table
What are the new systems and processes that were adopted at the Central & State level grid networks to identify frequency fluctuations and automatic disconnection of errant grid(s)?

Technical systems which include real time despatch, frequency meters, supervisory control and data acquisition system (SCADA), energy management system, etc., are deployed at load centres to monitor the frequency of power, at a given time. Measures such as frequency based automatic load shedding schemes, system protection schemes, primary response from generators through Free Governor / Restricted Governor mode of operation are, at present, in place to prevent grid outages and power swings. Further, RLDCs and SLDCs also keep a watch on the overloading of grid elements even under normal frequency band of operation and advice the concerned utility to check the overloading which may lead to grid outages/power swings

What are the measures taken to cope with grid operations in emergency situations like thunder storms and other natural calamities and eventualities?
The Disaster management related provisions of Grid Standards Regulations of CEA specify the measures to be taken during such emergency situations. (Ref: Regulation 31 of CEA's Grid Standards Regulations, 2010)

'Policy, market, technology addressing imbalances quickly'
IPCL Spokesperson
With the present system, is there any guarantee now that the states do not over-draw power and put the entire distribution system in peril? Are there more measures in the offing?
The transmission system in India is one of the largest interconnected transmission systems in the world. There are scores of entities either injecting or drawing power from the grid at all times. For maintaining grid stability, the policy and regulatory measures taken including implementation of the ABT mechanism as also the DSM and UI mechanism have had a huge role to play in creating a self-correcting frequency balancing system.

Furthermore, there have been several steps taken to develop an ancillary market as well as provide avenues through power market mechanism to buy or sell excess power rapidly through 24 x 7 power markets, TAM - Intraday etc., now the entities have avenue to either purchase from organized market or sell in organized market rather than relying upon deviation from schedule.

In addition, there have been several steps taken to enhance the technology available to visualize the status of the grid as well as automatic grid islanding and system protection schemes at various levels of system operations at the SLDCs, RLDCs and the NLDC to ensure that there is quick reaction to any instability in the grid.

Therefore, there is a significant role for three critical factors, namely - policy and regulatory measures, market mechanics as well as technology - in ensuring that grid participating entities with load-generation balance responsibilities are able to manage temporal deviations smoothly by addressing load and generation imbalances quickly and effectively.

With better interventions of the aforesaid three critical factors, it is expected that any load-generation imbalances are immediately handled and do not result into unscheduled interchanges that impact the stability of the grid.

India has witnessed a massive power grid failure in July-August 2012 due to overdrawing by some states. What are the steps taken from then on to improve Grid Discipline?
The massive grid failure of July 2012 can be viewed as the challenge the Indian power system was facing since long. Few to highlight are as below:
Situational Issues: Sudden spurt in agricultural/weather beating demand in NR region on account of monsoon failure, combined with surplus from WR region by higher generation availability and significant under-drawal by constituents. This resulted in heavy power flow towards NR region from WR and ER. The power flow from WR-ER link was against the envisaged power flow as per planning.

Apart from this, the 765 kV Bina-Gwalior-Agra II line was under shutdown.
Grid Indiscipline: The constituents of WR and NR region ignored the regulatory compliances with respect to notices issued by regional load despatch agencies and continued with under drawal/Over-injection in WR and overdrawal in NR region.

There was an absence of Primary response from generators even with rising frequency, which on 30th July was 50.95 Hz and rose to 51.4 Hz on 31st July.

Technical Issues: That day 400 kV Bina-Gwalior-Agra II was under shut down and 400 kV Zerda - Kankroli line also tripped, this resulted in significant reduction in reliability margin. Furthermore, there was a lack of system protection scheme in 400 kV Bina-Gwaliar-Agra II.

There was no consideration of N-1-1 criteria in transmission planning, which led to reduced margin for reliability.

Failure of defence mechanisms/safety net in the form of load shedding schemes through Under Frequency Relays, Rate of change of frequency relays and islanding schemes in the NR and ER were observed.

Institutional Issues: Lack of adequacy and competency of manpower as well as availability of suitable tool at load despatch centers. Lack of PMU based synchronization technology leading to insufficient visualization and situation awareness at regional and state load despatch centres.

Regulatory Issues: The prevailing CERC (Grant of Connectivity, Long-term Access and Medium-term Open Access in inter-State Transmission and related matters) permitting connectivity to the grid even without identification of beneficiaries at the time of application are resulting in unforeseen power flows across the synchronous grid.

Apart from above, the excessive reliance on UI rather than organized market for meeting demand requirements without any financial deterrents has enhanced in UI causing frequency issues.

As per the Clause 5.2(m) of the CERC (Indian Electricity Grid Code) Regulations, 2010, prevailing range for grid frequency in India was 49.5-50.2 Hz. To contain the large variation in trans-regional power flow for a small variation in grid frequency the CERC (Indian Electricity Grid Code) (First Amendment) Regulations, 2012 envisaged tightening of the permissible range of frequency to 49.7- 50.2 Hz. However, the above Regulation has been stayed by the Hon'ble Madras High Court. This also contributed in whatever small manner towards grid destabilization.

Further to the massive blackout, CERC took cognizance of the issue and directed POSOCO and CTU to investigate the matter and present final report along with recommendations to avoid such instances in future.

Few of the steps taken thereafter can be summarized as below:

  • Instructions were given to for deployment of System Protection Schemes (SPS systems) in NR region to curtail load in NR region in case of loss of injection from 400 kV Agra-Gwalior lines
  • Extensive audit of protection system was instructed and initiated
  • Defense plan of the states has been instructed and initiated to employ special protection schemes, Islanding schemes and automatic demand management schemes.
  • CERC introduced CERC (Ancillary Services Operations) Regulations 2015 along with detailed procedure to have dynamic reserves and primary response from generators in case of contingency events
  • CERC introduced CERC (Deviation Settlement Mechanism) Regulations 2014 to introduce tightening of the grid frequency with further narrower band of 0.1 Hz, which was earlier in band of 0.2 Hz.

Are there any penal provisions or fines for violations that have come into force for ensuring grid discipline, what are the provisions governing them? What is the outcome of implementation of penalties and other provisions?
CERC (DSM) Regulations 2014, itself provides for provisions with respect to schedule deviation beyond the permissible frequency band.

CERC (DSM) Regulations 2014 was further amended to include the definition of error by drawing and generating entities against their schedule to let respective load despatch agencies initiate necessary action to contain such behavior. The regulation now not only includes charges for deviation at frequency linked rate, but also introduces additional surcharge for deviations with narrow frequency band.

If any load dispatch center observes such behavior consistently, then it may approach CERC for seeking direction against the errant drawing or generating entities against the regulatory non-compliance.
Section 142 of the Electricity Act 2003 provides powers to CERC to penalize entities not complying with regulations and directions of CERC.

What are the new systems and processes that were adopted at the Central and state level grid networks to identify frequency fluctuations and automatic disconnection of errant grid(s)?
The massive blackout's aftermath has initiated plethora of schemes towards system strengthening and correcting deviations in power system. Few to mention are as below:

  • PGCIL has initiated implementation of PMU based Synchrophasor technology to ensure greater visualization of regional data.
  • With synchronization of SR with NEW grid, the benefit of larger integrated grid may be realised as now the change in frequency even for a large change in Load or Generation might be small
  • PGCIL started allowing publishing Aggregate Transfer Capability data on periodic basis with expeditious review to incorporate any real time changes in system
  • SPS systems have now been installed in all trans-regional and intra-regional links which cater to demand or generation sensitivity.
  • RLDCs have been identified with procedure to introduce ancillary services to contain grid deviation from benchmark in case of contingencies
  • SCADA and telemetry has been introduced with greater accuracy level incorporating advance technological features for real time data updation among SLDCs and RLDCs with NLDC.

What are the measures taken to cope with grid operations in emergency situations like thunder storms and other natural calamities and eventualities?
PGCIL and POSOCO have introduced Emergency Response Management System with detailed protocol and procedure defined for pre-defined agencies in the event of natural calamities or eventualities.

Apart from this, the latest Smart Grid focused technological intervention (FACTS, Transmission lines with dynamic line rating systems, Phasor data concentrators etc) has significantly improved reliability of power system.

As a seasoned industry leader/transmission company, what is your contribution to the stability of the grid and what are your future plans?
Though the system operation is the responsibility of statute notified agencies, each and every stakeholder is mandated with unwritten responsibility of ensuring grid compliance. A small list of activities can help contributing towards grid security, few to mention are as below:

  • Adherence to Scheduled Drawal/Injection
  • Adequate reactive compensation either by FGMO in generation or by having SVCs in distribution system
  • Employing N-1-1 transmission and distribution planning criteria in design linked with grid

Prayas Experiment
Prayas, an NGO working in power sector too, has started an experiment. It has introduced a simple device which can be installed at a factory or residence. It gives the voltage, frequency and interruption levels, and a SIM card is provided in that. Depending upon the area, they are collecting that data. It is on a small scale now, around 350 devices were given, most of it in Maharashtra, but some outside too. But it does not help, unless you do this on a statistical sample basis, on a larger scale. The cost of this device is only Rs 7000 at present, and there are two manufacturers of the device in Pune. If they were to make it on a large scale, the costs will come down further, making it easily affordable.

If they are given to the consumers - residential or industrial, then they can challenge the discoms from different areas. They can go to the regulator and say see this is what the distribution company is doing. You have set a prescribed standard of performance, but it is not being met. That means they have to be penalised. That is, something like a movement that is required. Prayas does not have money to do it on that scale. Some kind of a consumer movement is to be started. (As told to BS Srinivasalu Reddy by Dr Pramod Deo)

- BS Srinivasalu Reddy

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