TYPE47 : Battery
General Description
The battery type is the same as the one described in the
TRNSYS manual except for an addition of self discharge and a
change in parameter input. The parameters have been divided in
two groups; a group that describes the battery cell (specific for
the type of battery) and another group that describes the setup
of the batteries. The first group of data is given in a data file
and this will make it possible to select different batteries from
a data base.
The self-discharge model is implemented at Fraunhofer
Institute in Freiburg, Germany by Wilfred Griesshaber and
Fredrick Sick.
Nomenclature
- a - Factor for temperature and voltage
- b - Factor for temperature and voltage
- I0sd - Self discharge current at T = T0
and U = U0
- Q - Capacity of battery (Ampere hours)
- Qmax - Maximum capacity of battery
- T - Battery temperature
- T0 - Temperature for I = I0sd and U
= U0
- U - Battery voltage
- U0 - Voltage for I = I0sd and T = T0
-
Mathematical Description
The mathematical equations used are the same as in the TRNSYS
manual except the self discharge model:
The self discharge is calculated from this equation:
Isd = I0sd * Q/Qmax * e[a(T-T0) + b(U-U0)]
TRNSYS Component Configuration
PARAMETER NO. DESCRIPTION
- 1 mode - mode for calculations (all modes need the
battery data even if the data are not needed).
- 2 lud - Logical unit number for the battery data base
- 3 Cp - Cells in parallel
- 4 Cs - Cells in series
- 5 Nbatt - Number of the selected battery in
the data base
- 6 Tbatt - Surrounding temperature of the
electrolyzer
- 7 Vc - Maximum charge voltage
- 8 Vcontr - <0 => Vd is
calculated
- >0 => Vd = Vcontr
- 9 Ictol - Iteration accuracy in Ampere
-
INPUT NO. DESCRIPTION
The inputs are the same as in the TRNSYS manual
OUTPUT NO. DESCRIPTION
The outputs are the same as in the TRNSYS manual except four
more outputs:
- 13 Isd - Self-discharge current
- 14 Qsd - Self discharge ampere hours
- 15 Psd - Self-discharge power
- 16 Pwfull - Power wasted because the battery
is full.
The data for a battery cell has to be given in a separate
file. The first line in this file will give the number of battery
cells given in the file. The for each different cell will have
two lines; the first line will give the number of the cell in the
file, the second line will give the data for the cell. The last
three parameters in the file have to be given even though the
mode does not require it. It does not matter what values they are
given in this case. The data file for the battery cell will be
like this (the third line (P1-P18) should not be in the file, but
are included here to show which data means what):
- 1,Batterycell
- 417 .9 2.5 29.3 2.00 1.18
.1 .1 1. -.0087 20. .1 2.07 2.13 2.2 0.0834 417 -417
- P1 P2 P3 P4 P5 P6 P7 P8 P9
P10 P11 P12 P13 P14 P15 P16 P17 P18
- P1 = Qmax : Rated capacity of battery cell
[Ah]
- P2 = Eff : Charging efficiency
- P3 = i1 : Parameter used to calculate the
additional voltage term from a given current in the Hyman
model
- P4 = k1 : Parameter used to calculate the
additional voltage term from a given current in the Hyman
model
- P5 = md : Cell type of parameters which
determine the shape of the I-V-Q characteristics for
discharging
- P6 = cd : Factor for capacity parameter on
discharge [-]
- P7 = sd : Factor for internal resistance at
full charge for discharge [-]
- P8 = gd : Coefficient of (1-F) in voltage
formulas for discharging
- P9 = mc : Cell type of parameters which
determine the shape of the I-V-Q characteristics for
charging
- P10= cc : Factor for capacity parameter on
charge [-]
- P11= sc : Factor for internal resistance at
full charge for charge [-]
- P12= gc : Coefficient of (1-F) in voltage
formulas for charging
- P13= esd : Extrapolated open circuit voltage
for discharge
- P14= esc : Extrapolated open circuit voltage
for charge
- P15= U0 : Basic voltage for self-discharge [V]
- P16= I0sd : Self-discharge-current [A] at
tbat=temp0(=20 C) and v=volt0 (2.2 V for lead-acid
battery)
- P17= IQmax : Maximum current (charge) [A]
- P18= IQmin : Minimum current (discharge) [A]
-
-
OUTPUT to file logical unit 6 will look like this:
- Parameters from file to battery,
unit xx:
- Qmax = 4.1700E+02 Eff =
9.0000E-01 i1 = 2.5000E+00
- k1 = 2.9300E+01 md = 2.0000E+00
cd = 1.1800E+00
- sd = 1.0000E-01 gd = 1.0000E-01
mc = 1.0000E+00
- cc = -8.7000E-03 sc = 2.0000E+01
gc = 1.0000E-01
- esd = 2.0700E+00 esc =
2.1300E+00 volt0 = 2.2000E+00
- I0sp = 8.3400E-02 IQmax =
4.1700E+02 IQmin = -4.1700E+02