Water evaporation algorithm: A new metaheuristic algorithm towards the solution of optimal power flow

A relatively new technique to solve the optimal power flow (OPF) problem inspired by the evaporation (vaporization) of small quantity water particles from dense surfaces is presented in this paper. IEEE 30 bus and IEEE 118 bus test systems are assessed for various objectives to determine water evaporation algorithm’s (WEA) efficiency in handling the OPF problem after satisfying constraints. Comparative study with other established techniques demonstrate competitiveness of WEA in treating varied objectives. It achieved superior results for all the objectives considered. The algorithm is found to minimize its objective values by great margins even in case of large test system. Statistical analysis of all the cases using Wilcoxon’s signed rank test resulted in p-values much lower than the required value of 0.05, thereby establishing the robustness of the applied technique. Best performance of the algorithm are obtained for voltage deviation minimization and voltage stability index minimization objectives in case of IEEE 30 and IEEE 118 bus test systems respectively

Fine Tuning of On-Board Traction Converters for High-Speed Electric Multiple Units at Depot

This article presents a meticulous exploration of on-board traction converters deployed in Electric Multiple Units (EMUs). The study involves the development of a comprehensive traction converter and control system, encompassing essential elements such as transformers, front-end rectifiers, and DC link capacitors. The precise control of the front-end rectifier’s switching states is crucial for achieving high-quality power. A new application of the advanced Hybrid Particle Swarm Optimization (Hybrid PSOS) technique for the optimization of controller parameters is presented. This parameter tuning process aims to minimize the integral time absolute error (ITAE), a critical metric governing the regulation of DC-link capacitor voltage. Simulation results showcase the impressive attributes of on-board traction converters, including low harmonic content, a high-power factor, and stable DC voltage. Additionally, a rigorous comparative analysis is conducted between Hybrid PSOS and other established algorithms like Symbiotic Organisms Search (SOS) and Particle Swarm Optimization (PSO). Hybrid PSOS traction unit outperforms SOS and PSO, with a minimal overshoot of 1.3401%, faster settling time of 0.2413 seconds, compared to SOS (0.3884 seconds) and PSO (0.5531 seconds). Total Harmonic Distortion (THD) for secondary line currents, the values are 12.48% for PSO, 2.17% for SOS, and 1.08% for Hybrid PSOS. Hybrid PSOS consistently demonstrates its superiority, significantly enhancing system performance and stability. This research underscores the substantial potential of on-board traction converters, emphasizing their role in facilitating efficient and stable electric multiple unit (EMU) operations