Topological interlocking within microprocessor-based control systems for substations

The paper deals with a new topological interlocking method which has been implemented in a microprocessor-based real-time control system for substations. This method eliminates the disadvantages of conventional interlocking methods based on Boolean equations and leads to increased switching security and enlarged operating possibilities. The first part of the paper describes the computer-internal representation of the switchgear topology and the computer-aided configuring of the data base. Next, the article turns to the decision-making process of the topological interlocking and the implementation as substation interlocking in a decentralized control system. Finally the paper outlines the essentials of intelligent switching sequences as an example of automation functions based on topological interlocking.