Optimal Sizing and Location of TSCs in Medium-Voltage Distribution Networks via the Sine-Cosine Algorithm

This paper addresses the optimal siting and sizing of thyristor-switched capacitors (TSCs) in medium-voltage distribution networks (MVDNs) to minimize the expected grid operating costs associated with energy losses by taking into account the annualized investments in TSCs. The sine-cosine algorithm (SCA) is applied to determine the location and sizing of the TSCs for reactive power compensation in MVDNs. The SCA approach is an effective math-inspired population-based metaheuristic optimizer that explores and exploits the solution space using sine and cosine trigonometric functions. A discrete-continuous codification is used to represent the location and sizing problem of the TCSC in MVDNs. The discrete part is related to the nodes where the compensators must be located. In contrast, the continuous aspect of codification is linked to the sizes of the TCSC. The proposed methodology was evaluated in the 33-bus grid system and compared to three metaheuristic algorithms: the Chu & Beasley Genetic Algorithm (CBGA), the Particle Swarm Optimizer (PSO), and the Black Widow Optimizer (BWO). Computational validations show that the BWO and SCA algorithms reach the best solution with a reduction of the objective function by around 11.22%. All the numerical validations are carried out in the MATLAB programming software using version 2022b.