Optimal Placement and Sizing of Synchronous Condenser to Enhance System Strength of a Renewable Energy Integrated Weak Grids

Ensuring the reliable and secure integration of renewable energy sources (RESs) into the weak grid presents several challenges, primarily due to their variability and connection via power electronic converters. These sources exhibit distinct behavior compared to conventional generators, leading to various difficulties, including a reduction in system strength. Insufficient system strength at the point of common coupling (PCC) can jeopardize grid reliability and security, leading to voltage instability, frequency instability and problems with protection devices. The Short Circuit Ratio (SCR) is a crucial measure of system strength at the PCC, which must have a sufficient value to mitigate voltage problems and enabled proper operation of protection devices during faults. To enhance system strength, one potential method can be Synchronous Condenser (SC), owing to its capability to provide fast reactive power support. However, for maximizing support from SC with minimized size, placement in the appropriate bus in the grid is a crucial necessity. To this end, a Genetic Algorithm (GA) based optimization method is proposed for the optimal sizing and placement of SCs to enhance system strength in the grid. The proposed approach is implemented in the IEEE 33 bus system and the optimized SCs performance is validated. The prompt support from SC positively impacts the fault level, resulting in an increase in system strength. This enhancement ultimately improves the overall strength and security of the grid. The Genetic Algorithm is implemented in MATLAB and the results are analyzed utilizing DIgSILENT PowerFactory platform.