Adani, Azure, ACME plants found non-compliant after grid disturbances
The Northern Regional Load Despatch Centre (NRLDC) has identified multiple renewable energy generating stations that failed to comply with Low Voltage Ride Through (LVRT) and High Voltage Ride Through (HVRT) requirements during two major grid disturbance events in April and May 2026. The findings were presented during the latest meeting of the Renewable Energy Sub-Committee of the Northern Regional Power Committee (NRPC).
The first event occurred on April 13, 2026, at 11:00 hrs, when a sharp voltage dip led to the loss of around 1,100 MW of renewable generation. NRLDC said no fault was observed, but the voltage dip resulted in widespread generation loss, with system frequency falling by 0.16 Hz.
The second event occurred on May 12, 2026, at 14:13 hrs after the 765 kV Sikar_2-Aligarh Circuit 2 tripped due to a phase-to-phase (R-B) fault. The disturbance resulted in the loss of around 1,500 MW of renewable generation, with frequency declining by 0.18 Hz.
Plants identified as non-compliant
For the April 13 event, NRLDC identified 10 renewable plants as non-compliant with the Central Electricity Authority (CEA) Technical Standards for Connectivity to the Grid. These included projects operated by Azure Power, ACME, NTPC, Rising Sun Energy, Gorbea Solar, SBSR Power Cleantech, ReNew Solar Urja, Adani Hybrid Energy and AMP Energy. Two plants, Renew Surya Jyoti Pvt Ltd and Neemba Solar Plant, were subsequently removed from the list after data review confirmed compliance.
For the May 12 event, NRLDC identified more than 21 non-compliant plants, including projects owned by Adani, Azure Power, ReNew, SB Energy, Clean Solar Power, Ambuja Cements, Essel Saurya Urja, ABC Renewable Energy, NTPC, Avaada and AMP Energy.
According to NRLDC, several generating stations were found to be non-compliant in more than 50% of the last four grid disturbance events analysed.
Failure to meet recovery requirement
Under the CEA Technical Standards, generating stations must remain connected during voltage disturbances, prioritise reactive power support and restore at least 90% of pre-fault active power within one second after voltage restoration.
NRLDC found that multiple renewable plants failed to restore the required level of active power within the stipulated time.
Data gaps affected analysis
NRLDC also reported that phasor measurement unit (PMU) data from more than 30 renewable plants was unavailable or not reporting during the two events, limiting detailed analysis.
Only two renewable energy developers, Avaada and Juniper, had submitted Root Cause Analysis (RCA) reports at the time of the meeting. Several developers, including Adani Group companies, ACME Group companies, Azure Power entities and NTPC’s Kolayat plant, were yet to submit RCAs. NTPC attributed the delay to pending support from inverter manufacturer KEHUA.
NRPC seeks faster compliance
The committee expressed concern over the limited submission of RCA reports and asked developers to strengthen in-house technical capabilities instead of relying primarily on original equipment manufacturers (OEMs).
NRPC directed all concerned renewable energy plants to submit pending RCA reports to NRLDC, ensure compliance with LVRT and HVRT requirements at the Point of Interconnection (POI), submit event data in accordance with the Indian Electricity Grid Code (IEGC) and CEA Grid Standards, and coordinate with inverter and power plant controller (PPC) OEMs to address the identified issues.
The committee also asked the National Solar Energy Federation of India (NSEFI) to take a more proactive role in coordinating with renewable energy developers and OEMs to improve compliance and ensure timely submission of RCA reports.
The featured photograph is for representation only.
