Grid Controller of India Limited (GRID-INDIA) is a division of the Ministry of Power, Government of India. The new name of Power System Operation Corporation Limited (POSOCO) is Grid Controller of India Limited (Grid-India) since 9 November 2022. It is responsible to monitor and ensure round the clock integrated operation of Indian Power System. It consists of 5 Regional Load Despatch Centres (RLDCs) and the National Load Despatch Centre (NLDC).

The load despatch functions, earlier handled by Power Grid Corporation of India Limited (PGCIL), have been entrusted to Grid-India (previously known as POSOCO).

Central Government, through Ministry of Power in exercise of the power conferred by sub-section (3) of Section 26 and sub-section (2) of Section 27 of the Electricity Act, 2003 by notification dt. 27 September 2010 in the Gazette of India, notified that the Power System Operation Corporation Ltd (POSOCO), a wholly owned subsidiary of the Power Grid Corporation of India Limited (a Government Company), shall operate National Load Despatch Centre and the five Regional Load Despatch Centers, with effect from 1 October 2010.

The subsidiary was set up on the recommendations of a government committee headed by Mr. G.B. Pradhan (additional secretary) in the Union Ministry of Power. To make load despatch centres, financially self-reliant and autonomous, the committee recommended independent and sustainable revenue streams. The move to separate the two functions is in keeping with the provisions of the Electricity Act, 2003, which seeks to separate commercial interests from load management functions. The Pradhan Committee report had recommended setting up a separate representative board structure overseeing the functions of the five regional load despatch centres (RLDCs) run by PGCIL—the northern, eastern, north-eastern, western and southern regions at that time. The subsidiary was eventually made a separate company effective from 2 January 2017.

Several steps were taken by Central Government and Regulators in formation of POSOCO. Some of the major milestones are listed below.

• Pre 1994: RLDCs were operated by CEA with budgetary support from Government of India.
• 1994–1996: RLDCs transferred in a progressive manner to POWERGRID. Budgetary support from GOI stopped.
• July 1998: CEA finalized an Ad hoc arrangement for reimbursement of RLDC expenses (Rs. 12 Crores for 1996–97)
• 8 May 2003: CERC approved RLDC fees and charges from 2000–2001 (Rs. 21.52 Crores in the starting year)
• 2005 onwards: ULDC scheme charges merged with RLDC fees & charges and approved by CERC
• 22 August 2006: Meeting among Committee of Secretaries to discuss upon constitution of Wholly Owned Govt. of India corporation to carry out all functions as an Independent System Operator.
• 5 November 2007: Interactive session convened by Ministry of Power with Forum of Regulators and State Government. Pradhan Committee on Ring fencing of LDCs constituted in Feb 2008 after this meeting.
• 4 July 2008: MoP Directive for creation of POSOCO, with Board Structure & gradual separation after 5 years.
• 11 August 2008: Gireesh B. Pradhan Committee Report on "Manpower, Certification and Incentives for System Operation and Ring-fencing Load Despatch Centres" submitted. Report accepted and a meeting called on 7 October 2008 by Secretary Power.
• 15 November 2008: Forum of Regulators (FOR) approves formation of ‘Forum of Load Despatchers (FOLD) and approves FOLD charter in Jan 2009.
• November 2008: Report of "Open Access-Theory and Practice", endorsed by Forum of Regulators.
• 20 March 2009: Power System Operation Corporation Ltd. established with the objective of ring-fencing operation; incorporated as a 100% subsidiary of POWERGRID with authorized share capital of Rs.200 crores.
• March 2009: Satnam Singh Task force report on "Capital Expenditure and Issues Related to Emoluments for Personnel in Load Despatch Centres" submitted.
• June 2009: Rakesh Nath Committee Report on "Manpower Selection, Recruitment Procedure and Tenures for Personnel in SLDCs"
• 18 September 2009: CERC Regulations for the Fees and Charges as envisaged under the Electricity Act 2003, thus providing financial autonomy of POSOCO.
• 19 March 2010: Dhiman Committee Report on "Training and Certification of System Operators" submitted.
• 23 March 2010: Commencement of Business by POSOCO.
• 1 June 2010: Transfer of manpower from POWERGRID to POSOCO on secondment basis.
• 9 June 2010: Ministry of Power designated National Power Training Institute (NPTI) as the Certification Authority for executives of SLDCs, RLDCs and NLDC for an initial period of 3 yrs. i.e. up to 31 March 2013
• 26 September 2010: Gazette notification by Central Govt. of India that the POSOCO a wholly owned subsidiary of POWERGRID shall operate RLDCs/NLDC w.e.f. 1 Oct 2010.
• 1 October 2010: POSOCO notified for operation of NLDC/RLDCs.
• April 2011 – September 2011: 6 batches basic certification training at PSTI Bengaluru
• November 2011: First online certification test completed leading to 266 certified operators.
• 15 March 2015: Sanction by President for setting up of POSOCO as Govt. owned company.
• 19 December 2016: Gazette notification by Central Govt. of India notifying POSOCO as a wholly owned Government company with effect from 3 January 2017.
• October 2018: Report on Capacity Building of Indian Load Despatch Centres by Forum of Regulators

• 9 November 2022: Name of POSOCO changed to Grid Controller of India Limited (Grid-India).

The POSOCO was formed as an umbrella organization to give a corporate structure to RLDCs and NLDC to ensure integrated operation of Regional and National Power Systems to facilitate transfer of electric power within and across the regions and transnational exchange of power.