Stability Improvement in Microgrids using Hybridization of Resistive type Superconducting Fault Current Limiter and Series Active Power Filter

Abstract

The conventional energy sources are depleting and population is increasing day by day. This is the time to look at alternative energies like non-conventional energy sources. In general, nonconventional energy sources like solar and wind are free from pollution and involves no fuel input cost moreover it is safe in energy extraction. These energy sources have some drawbacks as these power plants are not base load plants. They are peak load plants, so the continuity of supply is not possible, maintenance cost is high and synchronization process with the main grid is very difficult. newlineConsidering the advantages and disadvantages, a microgrid is developed with three DGs such as solar, wind and fuel cells and they are synchronized with main grid in the proposed work. The sources of solar and wind power are well established, but the development of fuel cells are at the innovative period. Nowadays, microgrid safety is a very challenging task for electrical engineers because the interconnection of DGs and the synchronization process is also difficult. In the microgrid, three different loads are used, and all are three-phase RL loads and their ratings are 150+J25 KVA, 450+J30 KVA and 200+J20 KVA respectively. newlineIn the proposed work, three DGs have different ratings. Solar and wind sources act as major sources and fuel cells act as a backup source. The transmission line voltage level 10.5 KV is used and it is connected to three-phase distribution power transformers. The developed three-phase voltages are giving to the loads. Phase- Locked Loop circuits (PLL) is used for synchronization of three DGs with the main grid. Abnormal currents are produced due to the interconnectedness of distributed generations, which causes the complete damage of the microgrid. newline