Increased Effectiveness of Photovoltaic Power Stations for Frequency Control in Off-Grid Regions

In many countries there are off-grid regions with different consumers that are not connected to the centralized power grid. Diesel power stations (DPS) based on diesel-generator units (DGU) having different capacity have traditionally been used for power supply in such regions. The mix of generating facilities is changing in off-grid regions following the global trend for decarbonization of the electricity generation sector. This is performed in the course of removal from operation of obsolete and worn diesel-generator units and putting into operation of renewable energy power generating facilities including hybrid power plants. Photovoltaic power stations (PV stations) play a significant role in this process. All PV stations are connected to power grids through inverters. The majority of PV stations utilize grid-tie inverters that require reference voltage from the grid to control their operation modes. Inverters can participate in frequency control within certain ranges. This is pre-determined by the algorithms included by the manufacturing plants to the automated control systems (ACS). The article covers the requirements set for the participation of PV stations in frequency control, the information about the protection settings of the inverters and the possibilities of their operation in emergency modes. The article also provides recommendations on the selection of the operation algorithms and the parameters for setting the PV station inverters. The necessity of using energy storage systems as part of the PV stations is substantiated with the view to improve the efficiency of the PV station participation in frequency control.