Basler Electric BE1-11g - Manual (Page 163)

9424200994 Rev N 151
Synchronizer (25A)
The synchronizer (25A) element is available only in styles GxxxxxxxSxxxxx and GxxxxxJxTxxxxx of the
BE1-11g and performs the following functions:
•
Compares the voltage magnitude, angle, and frequency of the phase voltage to the voltage
magnitude, angle, and frequency of the auxiliary voltage
•
Calculates the ideal time to close the breaker so that mechanical and electrical transients are
minimized
Element logic connections are made on the BESTlogic
™Plus screen in BESTCOMSPlus® and element
operational settings are configured on the Synchronizer settings screen in BESTCOMSPlus. A summary
of the logic inputs and outputs and operational settings appears at the end of this chapter.
BESTCOMSPlus Navigation Path: Settings Explorer, Control, Synchronizer (25A)
HMI Navigation Path: Settings Explorer, Control, Settings Group x (where x = 0 to 3), Synchronizer 25A
Element Operation
The synchronizer acts to align the generator voltage magnitude, frequency, and relative phase angle to
that of the bus.
VT Connections
The synchronizer element compares the phase (generator) voltage to the auxiliary (bus) voltage. Proper
connection of the voltage transformer inputs is vital for correct operation of the synchronizer element.
Caution
The Aux VT Connection must be properly selected on the Sensing
Transformers settings screen in BESTCOMSPlus. Refer to the
Configuration chapter for more information on this setting.
For clarification on single-phase VTP connections, refer to the Typical Connections chapter. The single-
phase parallel connections ensure that the zero-crossing circuit is always connected to the sensed circuit.
For single-phase sensing connections derived from a phase-to-neutral source:
Terminals Va (C13), Vb (C14), and Vc (C15) are connected in parallel. The single-phase signal is
connected between the parallel group and terminal N (C16).
For single-phase sensing connections derived from a phase-to-phase source:
Terminals Vb (C14), Vc (C15), and N (C16) are connected in parallel. The single-phase signal is
connected between terminal Va (C13) and the parallel group.
Note that the voltage monitor (described below) performs three of three testing for all connections. For
3W and 4W, phases A, B, and C are actually tested. For single-phase connections, the terminals are
connected in parallel as described above and the single-phase is tested three times.
Angle Compensation
Compensation for phase angle differences between the phase and auxiliary VT connections (including
single-phase VTP connections) are possible with the Angle Compensation setting.
Common system and sensing transformer combinations are shown in Table 58. This table assumes no
step-up or step-down transformer between the two measurement PTs. If the synchronization zone
includes a step-up or step-down transformer, the angle compensation required would be the sum of any
VTP/Vx mismatch, plus the transformer phase shift.
BE1-11g Synchronizer (25A)