between CB A and CB B is energized (DLLB) from substation 1 via the circuitbreaker A and energization of station 2 is done by CB B energization check devicefor that breaker DBLL. (or Both).1 2AEnergizingCheckUHighBusEnerg > 50 - 120 % of GblBaseSelBusUHighLineEnerg > 50 - 120 % of GblBaseSelLineULowBusEnerg < 10 - 80 % of GblBaseSelBusULowLineEnerg < 10 - 80 % of GblBaseSelLineUMaxEnerg < 50 - 180 % of GblBaseSelBus and/orGblBaseSelLineLine voltageBus voltageIEC10000078-4-en.vsdBIEC10000078 V4 EN-USFigure 96: Principle for the energizing check functionThe energizing operation can operate in the dead line live bus (DLLB) direction,dead bus live line (DBLL) direction, or in both directions over the circuit breaker.Energizing from different directions can be different for automatic reclosing andmanual closing of the circuit breaker. For manual closing it is also possible to allowclosing when both sides of the breaker are dead, Dead Bus Dead Line (DBDL).The equipment is considered energized (Live) if the voltage is above the set valuefor UHighBusEnerg or UHighLineEnerg of the base voltages GblBaseSelBus andGblBaseSelLine, which are defined in the Global Base Value groups; in a similarway, the equipment is considered non-energized (Dead) if the voltage is below theset value for ULowBusEnerg or ULowLineEnerg of the respective Global BaseValue groups. A disconnected line can have a considerable potential due to factorssuch as induction from a line running in parallel, or feeding via extinguishingcapacitors in the circuit breakers. This voltage can be as high as 50% or more ofthe base voltage of the line. Normally, for breakers with single breaking elements(<330 kV) the level is well below 30%.When the energizing direction corresponds to the settings, the situation has toremain constant for a certain period of time before the close signal is permitted.The purpose of the delayed operate time is to ensure that the dead side remains de-energized and that the condition is not due to temporary interference.12.1.2.4 Voltage selection M12321-3 v11The voltage selection function is used for the connection of appropriate voltages tothe synchrocheck, synchronizing and energizing check functions. For example,when the IED is used in a double bus arrangement, the voltage that should be1MRK 505 393-UEN B Section 12ControlLine differential protection RED650 2.2 IEC 219Application manual
