Dynamic Compensation for Large Solar Park Integration

Dynamic

Background

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.

Pilot Scope & Outcomes

The GTG-RISE pilot will enable Dynamic Reactive Power Control from NTPC’s NP Kunta (250 MW) Solar Park for providing voltage regulation services at PCC during evening/off peak solar generation timings. The key activities under this pilot are enhancement of existing control facilities and will enable Software/hardware retrofits and communication enablement at solar plant (SCADA system and solar inverters) and NLDC for generation of DRPC signal at NLDC, receiving the signal at solar plant and providing command to the inverter to regulate output.

The pilot will provide insights for interconnection standards, invertor specifications and regulatory mechanisms for dynamic reactive control and compensation. It would help States to develop/improve the appropriate standards and commercial frameworks to support greater RE integration into the grid.

Stage 1: Technical Support

  • Testing of Reactive Control and other parameters as per “Technical Standard for Connectivity to the Grid” regulations issued by CEA
  • Power quality measurement and development of mitigation strategy

Stage 1: Regulatory Support

  • Provide insights for techno-commercial pathways for regulators and STUs/LDCs for state transmission utilities/system operators; designing cost-effective mechanism to address voltage stability issues due to large RE parks
  • Knowledge Dissemination & Capacity Building of RE Generators, STUs and LDCs on framework for automatic reactive control

Pilot Progress

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.