SamplexPower Evolution Series Owner's Manual page 62

SECTIOn 4 |
4.5.3 Synchronized transfer of Power
Direct AC input from Grid and Generator can be fed simultaneously to separate AC Input
Circuits. Only one AC source is selected at one time. When both Grid and Generator are
available simultaneously, Grid has priority. To facilitate synchronization, transfer of power
from Grid to Generator or from Generator to Grid is always routed through the inverter.
4.5.4 transfer From inverter to grid / generator
When Grid / Generator becomes available, its voltage and frequency are checked if these
are within the programmed limits. If yes, the output voltage of the Inverter Section is
synchronized with Grid / Generator through Phase Locked Loop" (PLL). This synchronization
process takes few seconds. Once synchronization is completed, the load is transferred
instantly (within 1 ms) to Grid / Generator at Zero Crossing of the voltage waveform for
seamless transfer and for better protection of Transfer relay contacts. The unit now operates
in "Charging Mode" with the AC power from the Grid / Generator charging the batteries as
well as providing power to the AC loads.
4.5.5 transfer From grid / generator to inverter
When the unit is operating in "Charging Mode" with the AC power from the Grid /
Generator charging the batteries as well as providing power to the AC loads, the phase and
frequency of Grid / Generator are tracked continuously. In case Grid / Generator fails or is
disconnected, the inverter will be forced into transfer at voltage which is at the same phase
and frequency at which Grid / Generator had been disconnected. Load will be transferred to
the inverter within 16ms at zero crossing. The unit will now work in "Inverting Mode" and
the batteries will start discharging.
4.5.6 transfer between grid and generator
As discussed in "Transfer from Inverter to Grid/Generator" above, the EVO
Grid over the Generator input. If the EVO
the Grid input is restored, the EVO
transfer back to the Grid input. both operations are synchronized and the transfer is at the
zero crossing for a seamless transfer.
4.6 bAttery ChArger SeCtion
The battery Charger Section of these units is a powerful, 3/4 Stage, fully automatic battery
charging circuit. The same Isolation Transformer and the H-bridge configuration are used to work
in the reverse direction, ie. rectify the AC voltage from the Primary AC Power Source to PWM
controlled low voltage DC to charge the DC battery Source. That is why it is called a bi-directional
device. Normal 3-Stage Charging Mode consists of bulk, Absorption and float stages (Default).
4-Stage Equalization Mode consists of bulk, Absorption, Equalization and float. (The Equalization
Mode is selectable). Equalization Mode is desirable for the proper health of Wet Cell batteries.
further, the charging voltages and currents are programmable to take care of a wide range of
battery types like flooded, AGM, Gel Cell, Lead Calcium, etc.
Important battery charging features are as follows:
• Adaptive Charging Control
• Dynamic Input Power Diversion Control
• Parallel charging through External Charge Controller
• Temperature compensated charging
62 | SAMLEX AMErICA INC.
general Description & Principles of Operations
will transfer the load to its Inverter Section, and then
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is operating with the Generator input active and
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prioritizes the
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