Development of Digital Computer Programs for the Automatic Switching of Power Networks

In interconnected power system networks, for maintenance or other purposes, it is becoming increasingly necessary to observe numerous switching constraints in reorganizing the system for supply security following outages due to faults. The development of these constraints by deduction can become time consuming and tedious. This paper records the latest progress in the application of set theory to the determination of the many permissible switching operations in a small substation. The switching states, as they are called, are found by off-line digital computation from the basic constraints imposed on each switch. Digital subroutines based on Boolean and switching algebra are used. These subroutines are described in detail and the interpretation of the resulting output map containing the permitted switching sequences is given. The use of this output map by an on-line digital controller for network or substation control is discussed. It is concluded that by incorporating the proposed method with other functions which the controller could perform usefully within a power network, the risk of switching errors in a complex network can be reduced.