What is the principle of voltage transformer configuration?
1) If the main wiring is single busbar, single busbar segment, double busbar, etc., install three-phase voltage transformer on the busbar; when there is power on its outlet, it needs to be reclosed to check the synchronization or no voltage, and it needs to be parallel in the same period. Single-phase or two-phase voltage transformers should be installed on the line side.
2) For 3/2 main wiring, three-phase voltage transformers are often installed on the line or transformer side, and single transformers are installed on the busbar for synchronizing parallel and reclosing inspections for no-voltage and synchronous inspections.
3) The voltage transformer of the inner bridge wiring can be installed on the line side or on the busbar, but generally cannot be installed at the same time. Depending on the installation location, the protection function will be affected.
4) In the small ground current system, when it is necessary to check the line voltage or the same period, a two-phase voltage transformer should be installed on the line side or a voltage transformer should be installed between the wires.
5) In the large grounding current system, when the line has the requirement of checking the line voltage or the synchronization, the voltage extraction device should be selected first. 500kV lines are generally equipped with three capacitive line voltage transformers, which are used for protection, measurement and carrier communication.
