Universal Bypass Switch Unit
UNB
Operation Manual
UNB2357E / Page 10 (34)
6. Functions
6.1 Schematic-diagram
dd
L
N
L
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UNB - Steuerung
Static Switch Control
Wechsel
richter
Inverter
Ausgang
Output
Thyristoreinheit
SCR unit
Netz
Mains
F1
F2
Tr2
Tr1
Tr3
V1.1
V1.2
V2.1
V2.2
6.2 Electric function
6.2.1 General
A static electronic bypass switch is to be installed, if critical
consumers have to be switched without interruption between
inverters and mains supply with a reaction time not able to
reached with mechanical switch-elements. The STATIC
BYPASS SWITCH SBS guarantees the frequency - and phase-
synchronisation of the inverter with the alternative network
and a switch over time of the disturbed source to the
alternative-source within 0,5-3 ms, depending on the
adjusted sensitivity-tolerance. The return-switching takes
place interruption free in the zero-crossing of the current. In
the case of a synchronisation-disturbance between mains and
inverter(s), the switch back always takes place in the
current-zero-passageway.
6.2.2 Function-principles
The schematic diagram (picture 6.1) shows a functional
diagram of the STATIC BYPASS SWITCH SBS-configuration.
The switch over of connected load will be done via -two anti-
parallel connected thyristors per feeding, ( V 1.1 / V1.2 and
V 2.1 / V .2.2 ). The thyristor pair V 1.2 and V 2.1 switches
during the positive half-sine wave whereas V1.2 and V2.2
switches during the negative half-sine wave . The thyristors
are driven in continuous -ignition, so that the control current
is switched depending of the actual polarity of the output
current. The connected thyristors stacks contains both
thyristors of one feeder.
Picture 6.1:
Schematic
diagram Static
Bypass Switch
(SBS)