Abstract This paper proposes a new and practical probabilistic method for calculating reliability indices and costs associated with distribution substations that share spare transformers of a same group. Based on Monte Carlo simulation, the proposed algorithm considers the chronological representation of failure occurrences, and enhances previous methods by modeling emergency actions, such as transferring load to neighboring feeders and connecting a mobile unit substation to ensure electricity supply to customers during the replacement of failed transformers. Thus, spare transformer requirements with new acquisitions to replenish the stock or even to expand the system are probabilistically assessed. All waiting times associated to these actions can be duly represented by any probability distribution, including the usual exponential model. A more accurate calculation of reliability indices and costs associated with the interruption of consumers is achieved. The corresponding computational algorithm is used in several numerical applications, considering a class of transformers of a Brazilian electricity utility. The results of these applications are deeply discussed to demonstrate the practical relevance of the proposed method.

中文翻译：

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考虑负荷转移和移动单元变电站的配电变压器可靠性指标的概率评估

摘要 本文提出了一种新的、实用的概率方法来计算与共享同一组备用变压器的配电变电站相关的可靠性指标和成本。该算法基于蒙特卡罗模拟，考虑故障发生的时间顺序表示，并通过对紧急动作建模来增强以前的方法，例如将负载转移到相邻的馈线和连接移动单元变电站以确保在更换故障期间为客户供电变压器。因此，对新购置的备用变压器需求以补充库存甚至扩展系统进行概率评估。与这些动作相关的所有等待时间都可以用任何概率分布适当地表示，包括通常的指数模型。实现了与消费者中断相关的可靠性指标和成本的更准确计算。考虑到巴西电力公司的一类变压器，在多个数值应用中使用了相应的计算算法。对这些应用的结果进行了深入讨论，以证明所提出方法的实际相关性。