Atec Magna-Power-PQ-Series-III - Manual (Page 7)

M
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SPECIAL APPLICATIONS
FOR D SERIES FRONT PANEL
POWER WAVEFORM GENERATOR
PQD SERIES power supplies can be programmed to operate as a power
waveform generator. Each memory state needs to be programmed for
the desired voltage or current for a specific time period. An example of a
power waveform generator is exemplified by the figure on the right. In this
particular example, the voltage set point is changed in 10 second intervals
while the current, over voltage trip, and over current trip are kept constant.
To make the power supply repeat the voltage ramp, a time period of 9998
is entered for step 9. The programming causes the memory state to jump
back to 0 after completing step 8.
PHOTOVOLTAIC CELL SIMULATOR
Modulation enables the power supply to emulate different sources:
such as batteries, fuel cells, photovoltaic arrays, etc. To simulate a photovol-
taic array, connect terminal 24 of JS1 to terminal 25 of JS1, set the modula-
tion control parameter to voltage control, and set the modulation type to 0.
The figure on the left illustrates the programmed piece-wise linear approxi-
mation for a typical photovoltaic array.
Sawtooth output voltage
IV characteristics for a typical photovoltaic array
VOLTAGE (VDC)
C
U
R
R
E
N
T
(A
D
C
)
11
0
10
0
90 80 70 60 50 40 30 20
35
40
20
30
25
10
15
5
10
0
1,2,20
VMOD
P/O JS1
25
REF GND
24
IO2
R1
+5
3.32 K
TYPICAL
AD592
U1
+
-
VO1REM-
VO1REM+
VS-
VS+
1
2
JS2
B1
VO-
VO+
MULTIPLEXER
D1 BATTERY CHARGER
The figure on the right illustrates a temperature compensated bat-
tery charger for applications with lead acid batteries. Diode D1, placed
between the power supply and battery, blocks current from flowing from
the battery to the power supply. This eliminates any loading on the battery
when the power supply is off, but more importantly, prevents the battery
from charging the power supply’s output capacitors. With deployment of
diode D1, remote sensing should be applied across the battery terminals to
compensate for the diode drop. By setting the voltage and current to the
bulk charge voltage and maximum charge current, the power supply will
initially charge the batteries in current mode control and then automatical-
ly crossover to voltage mode control when the batteries reach the desired
set point. The power supply can be programmed for time dependent, se-
quential step operation to equalize and float charge the batteries after bulk
charging. Equalization is generally not required for every charge cycle.
0
10
5
15
10
25
30
20
40
35
20 30 40 50 60 70 80 90
10
0
11
0
O
U
TP
U
T
V
O
LT
A
G
E
(V
D
C
)
TIME (SEC)
t
1 0 8 7 6 5 4 3 2 1 0
MEMORY
Battery charger with temperature compensation
M
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MAGNA-POWER ELECTRONICS, INC.
39 Royal Road Ph: (908) 237-2200 Email: [email protected]
Flemington, NJ Fax: (908) 237-2201 http://www.magna-power.com