Grid-India issues paper on grid-forming inverter technology
Author: PPD Team Date: January 7, 2026
Grid Controller of India Limited (GRID-INDIA) has released a detailed discussion paper on “Grid-Forming Technology and Possible Applications in the Indian Power System,” prepared by the National Load Despatch Centre (NLDC). The document reviews grid-forming (GFM) inverter technology, compares it with the currently used grid-following (GFL) systems, and invites stakeholder comments until 28 February 2026.
The paper places the discussion within India’s renewable transition. The country has set targets of installing 500 GW of non-fossil capacity by 2030 and achieving net-zero emissions by 2070. As of 31 July 2025, Variable Renewable Energy (VRE) capacity is 1,71,156 MW. Alongside this growth, the paper notes operational challenges between January 2022 and July 2025, when about 68 incidents involved renewable generation loss of more than 1,000 MW, mainly in Rajasthan, Gujarat and Karnataka. Causes included fault ride-through issues, inadequate voltage and reactive support, low-frequency oscillations under weak grid conditions, and low system strength measured by Short Circuit Ratio (SCR).
The document explains the core technology difference. Today, most utility-scale inverters in India are Grid-Following (GFL) devices, which function as current sources that synchronise using Phase-Locked Loop (PLL) signals and inject power based on commands. These work well in strong grids but face constraints in weak systems or when inverter penetration is high. In contrast, Grid-Forming (GFM) inverters act as voltage sources. They can establish and maintain voltage and frequency even without a strong external grid. According to GRID-INDIA, potential capabilities include stronger performance in weak grids, better voltage and frequency support, inherent synchronisation without PLL dependence, black-start capability and island operation.
Extensive simulation studies form a key part of the paper. Using test systems and an all-India model focused on Rajasthan, NLDC evaluated 20% , 30% and 40%penetration of GFM alongside different placement strategies. The findings indicate stable operation under low SCR conditions, improved voltage stability, faster system recovery after disturbances, a reduction in the Rate of Change of Frequency (RoCoF), and progressive benefit with higher GFM adoption. The study also notes that concentrated GFM deployment strengthens local clusters, while distributed deployment supports broader system stability.
The document reviews international experience, referencing operational projects such as Hornsdale Power Reserve and Dalrymple in Australia, Blackhillock in Great Britain, Kapolei Energy Storage in the United States and the Amaala microgrid in Saudi Arabia. It also observes ongoing global development of GFM standards by AEMO, NGESO, ENTSO-E and the Universal Interoperability for Grid-Forming Inverters (UNIFI) consortium.
Based on its assessment, GRID-INDIA suggests the targeted introduction of GFM capability. Key recommendations include considering mandatory GFM capability for new large Battery Energy Storage System (BESS) projects above defined capacity thresholds, such as 50 MW, especially in weak-grid areas, launching large pilot projects, gradually aligning national technical standards with global frameworks, and ensuring coordinated implementation between technology providers, developers, system operators, regulators and policy agencies.
The paper concludes that grid-forming technology could play an important role in maintaining stability, resilience and reliability as India moves toward a renewable-heavy and inverter-based power system.
The featured photograph is for representation only.