The associated daily maintenance effort and cost has been increasing with the growing use of high-voltage (HV) cable circuits. This study proposes a time-delay concept-based approach to maintenance scheduling of individual HV cable components, to allow periodicity of inspection to be optimised with consideration of time-delay interval between the instant of defect inception and final failure. Here, the progress from a defect to its resultant final failure can be represented as a two-stage process, one being a stochastic process of defect arrival and the other being a delay-time interval from defect to failure. Then an optimisation model is established to schedule maintenance activities based on the two statistical processes, where the objective function is set as the minimal maintenance cost. Cable circuits are divided into five components in accordance with the objects of inspection and testing. The components within different service ages are considered individually in the statistical models, and their accumulate failure numbers during each service year are used to automatically formulate and update periodicity of inspection. To illustrate the feasibility of the approach proposed, theoretical analysis on thousands of cable circuits are carried out. Results show that the economic expenditure could be reduced by 22.2% after optimisation.

随着高压（HV）电缆电路的使用日益增加，相关的日常维护工作和成本一直在增加。这项研究提出了一种基于时延概念的方法来维护单个HV电缆组件的维护计划，以允许在考虑缺陷出现时刻和最终故障之间的时延间隔的情况下优化检查的周期。在这里，从缺陷到最终的最终故障的过程可以表示为两个阶段的过程，一个过程是缺陷到达的随机过程，另一个过程是从缺陷到故障的延迟时间间隔。然后，基于两个统计过程建立优化模型以安排维护活动，其中目标函数被设置为最小维护成本。电缆电路根据检查和测试的对象分为五个部分。在统计模型中单独考虑了不同使用期限内的组件，并且在每个服务年度中它们的累积故障编号用于自动制定和更新检查周期。为了说明所提出方法的可行性，对数千个电缆电路进行了理论分析。结果表明，优化后的经济支出可以减少22.2％。为了说明所提出方法的可行性，对数千个电缆电路进行了理论分析。结果表明，优化后的经济支出可以减少22.2％。为了说明所提出方法的可行性，对数千个电缆电路进行了理论分析。结果表明，优化后的经济支出可以减少22.2％。