In a recent development, ACME Jodhpur Solar Power Pvt. Ltd. (ACME Jodhpur), ACME Rewa Solar Energy Pvt. Ltd. (ACME Rewa), and ACME Solar Holdings Private Limited (ASHPL) have filed a petition on September 15, 2022, urging authorities to address persistent voltage tripping issues at the 220 kV Bhadla Grid Sub-station in Rajasthan. ACME Solar is seeking compliance with the Rajasthan Electricity Grid Code Regulations 2008 (as amended) and Indian Electricity Grid Code Regulations 2010 (as amended) while also requesting compensation for their loss of generation.
ASHPL, the parent company, had established ACME Jodhpur and ACME Rewa as Special Purpose Vehicles (SPVs) to develop 100 MW Solar Power Projects each at Bhadla Phase-III Solar Park in Rajasthan, operated by Saurya Urja Company of Rajasthan Ltd. (SUCRL). These projects play a vital role in supplying solar power through a dedicated line connected to SUCRL’s 33/200 kV Pooling Sub-Station located at Bhadla, Phase-III Solar Park. This substation acts as the point of interconnection with the grid, and it is further linked to the Rajasthan Vidyut Prasaran Nigam Ltd. (RVPN)’s 400/220 kV Grid Sub-Station (Bhadla GSS) through two 220 kV transmission lines.
However, ACME Solar has been grappling with severe over-voltage and under-voltage issues at the Bhadla GSS since 2018. These problems have led to abnormal tripping of solar inverters, damage to electrical components, and significant loss in power generation. The consistent under-voltage problems have hindered the projects from operating at their full potential. Despite repeated attempts to address the issue and seek redressal, neither the situation has improved nor has RVPN taken any steps to remedy it.
Despite SUCRL acknowledging the voltage tripping issue, no remedial measures have been undertaken by RVPN, and the State Load Despatch Centre (SLDC) has similarly failed to resolve these disturbances. These disruptions have had a severe impact on energy generation by ACME Solar, resulting in financial losses and added stress on the substation equipment, making daily operations increasingly challenging.
SUCRL has also expressed concern over the voltage issues at Bhadla GSS and has requested RVPN, to address these problems, but to no avail. Contrary to RVPN’s claim that no tripping occurred at the 220 kV GSS RVPN Bhadla end from April 2021 to October 2022, except due to supply failure from other sources, ACME Solar asserts that their projects suffered significant generation losses due to voltage fluctuations at Bhadla GSS.
To pinpoint the root causes of under-voltage, ACME Solar enlisted the services of Hitachi Energy India, which conducted a steady-state analysis. According to Hitachi’s report, the evacuation constraint and tripping issues are linked to problems at Bhadla GSS, which falls under the jurisdiction of RVPN and SLDC.
As a permanent solution, RVPN verbally confirmed the installation of a 500 MVA Transformer at the 400 kV Bhadla GSS. Additionally, SLDC discussed the low voltage and tripping of 220 kV transmission lines from SUCRL’s Pooling Sub-Station to RVPN’s Bhadla GSS. They proposed disabling the under-voltage protection on these lines to prevent unnecessary tripping, highlighting that the Indian Electricity Grid Code (IEGC) does not contain provisions to trip a feeder under low-voltage conditions.
The regulatory commission has examined the petitioners’ concerns and the compensation sought, which amounts to ₹5.80 Crore for revenue loss. They note that while the petitioners point to grid disturbances and low voltage at Bhadla GSS, the Respondents partly attribute the issue to generators not providing the required reactive support. The Central Electricity Authority’s (CEA) Technical Standard for Connectivity to the Grid Amendment Regulations, 2013 is cited, emphasizing the importance of generators supplying dynamically varying reactive power support to maintain the power factor within specified limits.
The commission acknowledges the significance of dynamically varying reactive support in ensuring voltage stability and grid reliability. They stress the need for generators to supply or absorb reactive power to counterbalance low or high grid voltage and bring it within nominal values. Therefore, the commission directs the petitioners to make suitable arrangements to inject or draw reactive power by the Central Electricity Authority Regulations.
Furthermore, the commission issues directives to RVPN and SLDC to take all necessary actions to maintain voltage within specified limits, thus ensuring a more stable and reliable grid for the benefit of all stakeholders involved in the solar power projects at Bhadla Phase-III Solar Park.
The petitioners’ concerns regarding persistent voltage tripping issues at Bhadla GSS have prompted regulatory attention, with directives aimed at resolving these problems and ensuring a more stable and reliable grid for the affected solar power projects.
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