Section 15 Control15.1 Synchrocheck, energizing check, and synchronizingSESRSYN15.1.1 IdentificationFunction description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberSynchrocheck, energizing check, andsynchronizingSESRSYNsc/vcSYMBOL-M V1 EN2515.1.2 Application15.1.2.1 SynchronizingTo allow closing of breakers between asynchronous networks, a synchronizingfeature is provided. The breaker close command is issued at the optimum time whenconditions across the breaker are satisfied in order to avoid stress on the network andits components.The systems are defined as asynchronous when the frequency difference between busand line is larger than an adjustable parameter. If the frequency difference is less thanthis threshold value the system is defined to have a parallel circuit and thesynchrocheck function is used.The synchronizing function measures the difference between the U-Line and the U-Bus. It operates and enables a closing command to the circuit breaker when thecalculated closing angle is equal to the measured phase angle and the followingconditions are simultaneously fulfilled:• The voltages U-Line and U-Bus are higher than the set values forUHighBusSynch and UHighLineSynch of the respective base voltagesGblBaseSelBus and GblBaseSelLine.• The difference in the voltage is smaller than the set value of UDiffSynch.• The difference in frequency is less than the set value of FreqDiffMax and largerthan the set value of FreqDiffMin. If the frequency is less than FreqDiffMin thesynchrocheck is used and the value of FreqDiffMin must thus be identical to thevalue FreqDiffM resp FreqDiffA for synchrocheck function. The bus and line1MRK 502 071-UEN - Section 15ControlGenerator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062 479Application manual
