Optimizing Bipolar Current Transformer Arrays for Sustainable Energy Harvesting in Smart Grids

Environmental energy harvesting from magnetic fields offers a sustainable power solution for smart grid sensors. This study optimizes bipolar current transformer arrays for enhanced energy harvesting from microcurrents to meet load requirements. Based on the current transformer array model, a mathematical model that captures the polarity conversion characteristics is constructed. Incorporating both polarity conversion properties and power management integrated circuit limitations, a multi-constraint array optimization problem is constructed. Furthermore, a binary grey wolf optimizer is then introduced to address this optimization challenge. Our findings reveal that the optimal current transformer array configurations for primary current RMS values of 500 mA, 700 mA, and 900 mA are <inline-formula> <tex-math notation="LaTeX">$12\times 1$ </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">$6\times 2$ </tex-math></inline-formula>, and <inline-formula> <tex-math notation="LaTeX">$4\times 3$ </tex-math></inline-formula>, respectively, achieving the highest power duty cycles of 26.45%, 57.86%, and 100%. The energy extraction efficiencies reach 59.39%, 65.21%, and 76.26%, while energy conversion efficiencies are 89.01%, 92.55%, and 87.45% under the optimal configurations. This work provides a practical framework for designing efficient bipolar harvester arrays, ensuring stable energy supply in smart grid applications.