Fault Ride Through of Solar Photovoltaic Based Three Phase Utility Interactive Central Inverter

The purpose of low voltage ride through the requirement for utility-interactive type inverters like microinverters, string inverters, and central inverters is to maintain the grid stability, power loss reduction, voltage support/boost by reactive power support during sudden fluctuations in grid voltage. In this paper, the performance of solar PV-based grid-connected central inverters of 350 kW is evaluated during its operation of low voltage ride through (LVRT), high voltage ride through (HVRT), and frequency ride through (FRT). The evaluation is based on “Technical Standards for grid connectivity,” published by CEA, India, in February 2019. The inverter is evaluated at a power of 350 kW using the grid simulator of the 540 kVA facility available at the CPRI laboratory. The LVRT, HVRT, and FRT results show that this central inverter can qualify for the fault ride-through requirements mentioned in the CEA Regulations 2019. This paper also shows the gaps in the standard for evaluating the fault ride-through in an inverter and recommends a few suggestions that need improvement to make the standard more stringent and clearer. Finally, the proposed recommendations' industrial implications and limitations are provided in the conclusion section.