15
The Evolion is designed to provide low power to the application for autonomies ranging from 2 hours and 5 days. When providing this
duty, the voltage of the Evolion operates with the typical voltage range of a 48 V nominal telecom bus.
5.1 Normal operating voltage limits
The Evolion operates in a range of 42 Vdc to 56 Vdc measured on the module terminals.
At 56 Vdc or an average cell voltage of 4.0 Vdc, the state of charge (SoC) is 100 %. In that state, the charge current accepted by the
Evolion is approximately equal to the internal electronic load and the cells’ self-discharge rate, which is typically less than 0.1 A.
At 42 Vdc or an average cell voltage of 3.0 Vdc, the SoC is 0 %. A low voltage disconnect (LVD) is automatically operated anytime a
module decreases to 42 Vdc (alarm #36). In that case, the Evolion module will remain active in safe mode until it automatically goes
into sleep mode to avoid over discharge.
The operating voltage must be higher than 49 Vdc to keep the cell balancing circuits active during re-charge. The typical float voltage
range is 54.6 (86% SoC) to 56.0 Vdc (100% SoC). The maximum State of Charge (SoC) of the Evolion is directly proportional to the
charge set point voltage. For every 1 V less than 56.0 V, the Evolion will stabilize at approximately 10% less than 100% SOC.
5.2 Cell self discharge
The cell self-discharge rate depends on the temperature.
Temperature (°C/°F)
% per week
20/68
0.60
40/104
0.85
0.85
5.3 Open Circuit Voltage (OCV) as a function of State of Charge (SoC)
The measured OCV is directly proportional to the %SoC. A linear approximation can be used. See the table and diagram below.
OCV intercept (Fractional %SOC = 0)
46.62 V
OCV Slope (0 to 1 where 1 = 100 %)
9.38 V per %SOC
5. Cell and module voltages
%SOC
OC V (open circuit voltage)
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
OCV (Linear) = 9.38 x (fractional %SOC) + 46.62
OCV of the Evolion module
Linear (Approximation)
Содержание evolion
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