8
6.0 FUNCTIONING
Hardware information :
The functioning of the energy station is based on an electronic converter which transforms the line voltage into a isolated
stabilised voltage while all the total running of ENERGY is carried out by an electronic circuit which shows, through a
display and control buttons, the functioning state of the system in real time.
The converter is composed by two sections the first called ‘power factor’ corrector and the second ‘dc/dc push-pull
converter’.
The PFC unit is used to limit the harmonic current equipment is allowed to draw from the main supply. This regulation is
based on the reccomedation of the european normative EN60555-2 . The PFC is composed by a main input voltage
rectifier, an inductor, a power switch (IGBT) and a diode. By controlling the mark space ratio of the switch it is possible
to make the current drawn from the supply closely approximate to a sine wave.When the switch is on the input current is
stored into the inductor. At this point the inductor voltage is reversed to the output capacitor when the power switch is
off. The output voltage of this section, about 400 Vdc, is the feeder of the second section of the energy station.
The dc/dc section, bridge push-pull converter, is composed by a power switches ( IGBT ), an high power transformer and
an output rectifier. An integrated circuit, compare the output voltage with an internal precision voltage reference,
producing a step wave voltage with a variabile duty cycle. The power switches, used as bridge converter, produce a
simmetrical square wave voltage utilized to drive an high power transformer.The high frequency transformer guarantees
the input and output isolation, and using a different primary to secondary turns ratio, it convert the high input voltage
present in the primary side in a low output voltage in the secondary side. The output voltage, square wave, is then
rectified and filtered by an inductor and a capacitor to produce a smooth d.c. voltage.
Whether the line is present or not, an separated fly-back feeder circuit provides the voltage supply for the logic and the
microprocessor. When the energy station is operating on battery mode, a relay disconnects the battery and the load if the
voltage level it’s fall below the 43Vdc level.
This is to prevent an excessive discharge of the battery.
Software information :
The microprocessor board, together with analog and digital sensors, controls all the electric parameters as voltages,
currents, fuses and working temperature and their parameters visualized on the main lcd display. When the microcessor,
checking the values acquired, detects a failure visualizes the error message on the main display, stores the information
in the historical register and sets on or offs the corresponding alarm relay.
The free contacts of these relays are useful for telecommunication users, moreover the system parameters and alarm
message are sent trough the Lan interface. An browser program's and a personal computer are necessary to display this
messages. The energy station is also provided with a CAN-BUS interface used to connect together multiple rectifiers in
order to share information and alarms. The single rectifier unit when powered on the first time take automatically an ID
number and save it on memory. Three ID number are present when the SCS2ENMD48 is configured with three rectifier
units. This ID numbers are necessary to visualize the working condition of the selected rectifier on display panel. Three
menù M1,M2,M3, corresponding to the three rectifiers, are present on the display. When I select the M1 menu I can read
the output current, the output voltage, the working temperature and the input AC voltage of the M1 rectifier and at the
same time the green led of the selected rectifier, blinks. In failure case of one rectifier: power-off the broken rectifier
using the front panel switch and remove it. Insert the new rectifier and power-on using the front panel switch. The led
green and red should flash together for a few seconds, the only green led on indicates that it works and the new ID
number has been assigned.
7.0 Display Menù
7.1 Symbol present:
Display Symbol
Description
+
Move forward
-
Move back
P
Program
Enter
V = xx.xV
Output voltage (=voltage which feeds the charge).
VR = xxxV
Main input voltage.
I = xA
Total current supplied by the switching feeder (I = Iload + Ibat).
T = xx
Indicates the work temperature of the power modules (M1,M2,M2)
Iload = xx.xA
Current absorbed by charge.
Ibat = xx.xA
Current absorbed by batteries.
Mx
Rectifier module
