Dynamic Compensation for Large Solar Park Integration

Dynamic

With increasing RE penetration comes the need to address RE power output variability. Variability can cause frequency deviations and voltage instability. The former can be addressed through a combination of technology and operating practices. Voltage stability, however, needs to be addressed locally by State Transmission Utilities to maintain grid reliability as more RE is added into the grid. This issue poses a greater challenge for states such as Rajasthan, where RE parks are located far from load centers. It means the power they generate needs to be transmitted over a long distance, with its voltage regulated during that transmission.

MOP and USAID have agreed that one of the GTG-RISE pilots should focus on reactive power management issues associated with deploying large solar parks in RE rich states. The pilot will examine whether standards and regulations that address voltage stability in the state transmission network are adequate in the context of a particular solar park’s deployment. The pilot will help regulators design cost-effective mechanisms to address voltage stability.

The pilot scope includes assessment (and possible enhancement) of dynamic reactive power support capability of inverters for supporting RE interconnection point voltages during peak and off-peak generation at Ultra Solar Power Plant, NP Kunta in Andhra Pradesh. It will also evaluate inter se response of inverters vis-à-vis STATCOMs at various voltage levels to derive insights on what would be the most optimal / least cost choice for state transmission systems.

The pilot will model options for India’s RE-rich states as they consider how to ensure that solar power inverters and STATCOMs can adequately stabilize frequency fluctuations, and minimize the overall impact on power quality associated with RE deployment. The pilot outcomes will help states develop/improve the appropriate standards and commercial frameworks to support greater RE integration into the grid.

GTG-RISE team, with support from NTPC and POSOCO, has already finalize the scope of work and selection of grantee for the implementation of the AGC and DRPC pilot at both NP Kunta solar power plant and POSOCO, New Delhi is under progress. The next stage of the pilot aims at providing strategic control logics in AGC software and enablement of AGC and DRPC capability in solar inverters at NTPC’s 250 MW Ultra Mega Solar Power Plant, NP Kunta.