Research and Application of Multi-functional Backup Automatic Switch Based on Decoupling Theory for Substation

There are three kinds of main connection modes, including single bus connection, inner bridge connection and enlarged inner bridge connection, in the different stages of the construction of the internal bridge connection circuit for substation, which were equipped with one of the three backup automatic switching devices for a main connection circuit. The control logic control (decoupling control logic) composed of two inner bridge auto-restart control logic were adopted to realize the control logic expanded internal bridge connection auto-restart, by setting the control words for operation mode, and to achieve mufti-function auto-restart control logic principle schemes (two principle scheme) of primary connection circuit for expansion inner bridge, bridge and single bus connection. These adaptive functions for primary main circuit operation modes were achieved through judging the operation of gate position contact point of each circuit breaker and two position relay contact. The two kinds of decoupling principle of the multifunctional automatic switching device were developed according to these principles. Test results show that the multifunctional automatic switching devices can function adaptive for three main circuit standby automation switching and operation mode, to achieve the control logic to conduct the three main circuit automatic switching devices operation effectively, which has engineering application prospects.