Digital twin (DT) is a hot topic in information engineering, which has been introduced into the intelligent solution of the power grid system to deal with the reliability assurance issues of complex systems. Due to the lack of an operational application architecture model, it is impossible to map the complex system comprehensively. Based on the review of the concept model of DT and the current research situation in the smart grid (SG), an OKDD [i.e., ontology-body (OB), knowledge-body (KB), data-body (DB), and digital-portal (DP)] model of digital twin body (DTB) is proposed and specified in detail. Taking a vacuum circuit breaker and a 35 kV substation of the power grid as examples, the OKDD is applied in the DTB construction, and the developed prognostic and health management (PHM) system demo is practiced in a 110 kV substation simply. The approach is proved to be feasible preliminarily. This model provides a novel method for the unified description and standardization of DTB, which is conducive to the hierarchical creation (unit-system-system of systems) for complex systems. Meanwhile, it can represent complex physical entities more comprehensively, and enable the reuse of knowledge and the duplication of similar unit-level DTB rapidly. Thus, this research provides a new reference for the practical application of DT.

数字孪生（DT）是信息工程中的一个热门话题，它被引入到电网系统的智能解决方案中来处理复杂系统的可靠性保证问题。由于缺乏可操作的应用架构模型，无法全面映射复杂的系统。在回顾DT概念模型和智能电网（SG）研究现状的基础上，提出了一个OKDD[即本体（OB）、知识体（KB）、数据体（DB）和数字门户（DP）]模型的数字孪生体（DTB）被提出并详细说明。以真空断路器和电网35 kV变电站为例，将OKDD应用到DTB建设中，并在110 kV变电站简单地进行了开发的预测与健康管理（PHM）系统演示。初步证明该方法是可行的。该模型为DTB的统一描述和标准化提供了一种新方法，有利于复杂系统的分层创建（系统的单元-系统-系统）。同时，它可以更全面地表示复杂的物理实体，快速实现知识的重用和相似单元级DTB的复制。因此，本研究为DT的实际应用提供了新的参考。并实现知识的重用和类似单元级 DTB 的快速复制。因此，本研究为DT的实际应用提供了新的参考。并实现知识的重用和类似单元级 DTB 的快速复制。因此，本研究为DT的实际应用提供了新的参考。