Pan India 'lights switch off'

N Shyamsundar Singh *

On 5th April 2020, at about 2:30 pm, Shri. Y. Rupachandra Singh, Editor-in-Chief of IMPACT TV rang me up and asked me “Kaka, would you please come to the studio to-day at 5:30pm and take part as one of the panelists in the discussion on “Pan India Lights Switch Off” (Manunghutna) which is being telecast live”.

The topic was really interesting and I wanted to share the knowledge I have in it with viewers.

However, on a second thought, I found that I need to have more technical information and data like the total number of households/consumers in India, the peak demand, the load likely to be reduced due to switching off of the domestic lights, permissible system frequency band etc. with which I can highlight the facts in a more practical and simpler way.

These shortcomings that emerged following my long dissociation from relevant activities did not allow me to appreciate the proposal. Rather, it urged me to realize that I missed the opportunity to perform in the public interest because of my own failure to update knowledge in time in this high-tech-era.

The National Grid of India, the largest power supply network of its kind in the world, comprises mainly of several hundreds of generating plants of different designs and capacities, a large number of power stations and distribution sub-stations of various capacities and their associated transmission and distribution lines.

It also includes several switching & control stations and Load Despatch Centers designated as National Load Despatch Centre (NLDC), Regional Load Despatch Centre (RLDC) and State Load Despatch Centre (SLDC).

Few thousands of Power Engineers/ Power System Operators are working in close co-ordination with each other with the help of advanced communication system installed in these vital stations. These engineers are always keeping their eyes open round the clock to ensure trouble free power supply to crores of consumers of the country.

It is worth noting here that the synchronous operation of the vast National Grid as a single system is not an easy task and secondly, securing the system stability (synchronism) even in the transient odd situation like load throw off or load throw in is also equaling challenging for the operators.

Notably, the frequency may increase and go beyond 50 Hz which is the standard for the system where the demand decreases and vice versa. However, the changes in the frequency may be managed within the permissible operational frequency band through proper scheduling of the generating stations without losing the synchronism.

Their main concern is the consistent maintenance of the synchronism of the power system by all possible means.

Simply because, loss of synchronism shall cause total power failure and result in all kinds of damage and inconvenience which are something unimaginable particularly at a time when the entire nation is struggling against the fast spread of dreaded COVID – 19.

Therefore, the concerned engineers might have done exhaustive studies beforehand taking into consideration the possible fluctuations in the demand that may occur one at 9 pm and another after 9:09 pm.

The event passed off satisfactorily and it was a success of the people of India in general and of the power engineers in particular. It has also proved once again that the engineers are always a couple of steps ahead of others and they always look forward to developing technologies that meet the changing requirements of the users.

A Press Note, a self-explanatory that contains important details, circulated by the President, the Institution of Engineers (India) with the advice to approach the local media for wide publication in the interest of general public, is produced below.

Institution of Engineers (India) Congratulates Power Engineers of the Country for Excellent Operation of National Grid during pan India ‘Lights Switch Off’ Event.

Er. Narendra Singh, President, The Institution of Engineers (India) congratulated the power engineers of the Country working in National Load Despatch Centre, State Load Despatch Centres, Power Grid, DISCOMs, Transmission Utilities, NTPC, NHPC, SJVNL, THDC, IPPs etc. who rose to the occasion to meet this unprecedented challenge and managed the National Grid operations successfully, maintaining the power system parameters during the ‘lights switch off’ event on 5th April.

Heeding to the call of Hon’ble Prime Minister, about 23 crore consumers (18 crore rural households and 5 crore urban households), at 9 PM on 5th April, voluntarily switched off their lights for 9 minutes.

This resulted in abnormal load fluctuation – large reduction of power within 2-4 minutes and then sudden recovery 9 minutes later, which called for extremely careful planning and power management at the generation end as well as in the Transmission and Distribution elements.

While sharing the incident with Press and Media, President, The Institution of Engineers (India) said that the total reduction in all India demand recorded during the event was 31089 MW.

The all-India demand which was 1,16,880 MW at 8.45 pm started reducing, reaching a minimum demand of 85,799 MW at 9.10pm. Subsequently, the demand started picking up and settled to around 1,14,400 MW at 10.10pm.

The meticulous planning and grid management resulted in maintaining the Grid Frequency during the entire period in the range from 50.26 Hz to 49.70 Hz. The reduction of the total 10950 MW generation capacity during this period was shared by the three major sources - thermal (6992 MW), gas (1951 MW) and wind generation (2007 MW).

Advance actions such as switching off transmission lines, changing SVC, STATCOM, HVDC set points etc. were taken prior to the event for keeping voltages and line loading within permissible limits.

Er. Narendra Singh, President, The Institution of Engineers (India) said that in this challenging conditions, operation of Indian National Grid, which is largest Synchronous Grid in the world, with stability, has been a momentous and remarkable achievement for which Power engineers of the country deserve accolades.

While lauding the extraordinary work being done by medical professionals in fighting the COVID19 pandemic, he highlighted the fact that engineers are contributing significantly during this ‘lock-down’ period by maintaining a variety of essential services and many are also engaged in innovating much needed cost-effective medical equipment such as ventilators.