Electrocoalescence of water droplets in oil is a key mechanism in crude oil dehydration, yet the effectiveness of pulsed electric fields is not fully explained. This study uses numerical simulation of droplet pairs to investigate conditions under which the electrocoalescence threshold exceeds that of a constant field. The analysis covers variations in duty cycle, droplet radius, viscosity, and interfacial tension. A frequency range is identified where the root-mean-square threshold increases, reaching up to 20% at a duty cycle of 12.5%. The effect is strongest at an Ohnesorge number ( Oh ) near 0.5, diminishes at higher values ( Oh > 1.5), and does not intensify further at lower values. The phenomenon appears linked to droplet relaxation and collision dynamics, while resonance may overlap but is not its primary cause. These results clarify the physical basis of threshold elevation under pulsed fields and provide guidance for optimizing electrocoalescer performance in industrial emulsion separation. © 2026 Elsevier B.V.