A hierarchical installation-trajectory co-optimization method for cost-efficient acquisition of partial discharge ultrasonic signals

Partial discharge (PD) ultrasonic monitoring is widely used for insulation fault diagnosis in switchgear, while its performance is often limited by insufficient signal acquisition quality under practical installation constraints. This paper proposes a cost-efficient PD ultrasonic signal acquisition method based on hierarchical installation–trajectory co-optimization using a spiral array–guide rail system. By formulating the acquisition process as a hierarchical optimization problem and jointly optimizing guide rail installation parameters and inspection trajectories, the proposed method enhances signal reception strength and spatial coverage while reducing inspection path length without increasing system complexity. Simulation results under realistic substation configurations demonstrate the effectiveness, robustness, and engineering applicability of the proposed approach.