Abstract
Wireless power transfer (WPT) has emerged as a promising solution for electric vehicle (EV) charging due to its operational convenience, safety, and potential for automated operation. While inductive power transfer (IPT) has been widely implemented, it suffers from issues such as magnetic interference, high coil weight, and electromagnetic exposure. Capacitive power transfer (CPT) offers an alternative with advantages such as lower weight, lighter structure, and reduced electromagnetic interference. CPT systems often exhibit high-frequency operation and have plate-based coupling. This paper proposes four horizontally aligned six-plate CPT coupler configurations and compares their coupling performance under identical boundary conditions. The simulated coupling capacitance for the four couplers ranges from approximately 22 pF to 52 pF at a 150 mm air gap, while the circularplate coupler (HCC2) shows only about 10 - 12\% reduction under \pm 150-\text{mm} lateral misalignment. Additionally, all couplers maintain stable operation across 100-250 \text{mm} air-gap variation, validating suitability for EV underbody installation. The comparative analysis includes electric field intensity, coupling capacitance variation with plate length, misalignment tolerance, and air-gap dependence. These results provide design insights for horizontally aligned CPT couplers for EV charging.