Project 2 Thermal modeling of battery pack
A lithium-ion (Li-ion) battery is an advanced battery technology that uses lithium ions as a key component of its electrochemistry. During a discharge cycle, lithium atoms in the anode are ionized and separated from their electrons. The lithium ions move from the anode and pass through the electrolyte until they reach the cathode, where they recombine with their electrons and electrically neutralize. The lithium ions are small enough to be able to move through a micro-permeable separator between the anode and cathode. In part because of lithium’s small size (third only to hydrogen and helium), Li-ion batteries are capable of having a very high voltage and charge storage per unit mass and unit volume.
Li-ion batteries can use a number of different materials as electrodes. The most common combination is that of lithium cobalt oxide (cathode) and graphite (anode), which is most commonly found in portable electronic devices such as cellphones and laptops. Other cathode materials include lithium manganese oxide (used in hybrid electric and electric automobiles) and lithium iron phosphate. Li-ion batteries typically use ether (a class of organic compounds) as an electrolyte.
The following figure shows 20 cell series lithium ion battery model
So for 10cell thermal modeling
CELL SUBSYSTEM:
It consists of a thermal model,a lithium cell 1RC BLOCK which calculate temperature and thermal effects of cell.the block which are inside the subsystem are PS gain block and voltage(ideal voltage) and current sensor block.
THERMAL MODEL:
the important block in it are thermal reference,controlled heat flow rate source,thermal mass,temperature sensor.
LITHIUM CELL 1RC SUBSYTEM:
TEMPERATURE SUBSYTEM:
shows the temperature curves which are connected to GOTO tags with a scope outside this subsystem.
Tweaking the cell parameters
Cell 1-4
Cell 5 Fault
Cell 6-10
AFTER SIMULATING:
SOC
CELL TEMPERATURE
CONCLUSION:
Ambient temperature is 293.15k
cell pack 1-4 reaches 308k and 6-10 reaches 310k whereas cell pack 5 reaches 327k.
SOC starts from 0 and goes upto 1.95 in 300sec and again discharges to 0 in 300sec and the cycle keeps on repeating.
Life cycle of the battery pack is 6cycles per hour.