Project 5

Solution: IN this model we use 10 series configuration of the lithium-ion battery pack. These are all battery cells connected in series. This battery pack charges or discharges by using the controlled current source and signal build in signal builder. For this cell enables the temperature effect and aging effect option for observing and estimating the temperature. So, in this model I can estimate the age of the cell, SOC of the battery pack, battery pack temperature, ambient temperature, battery pack current by the using a bus selector from any one cell of the battery pack, because this battery pack is made from connecting the cells in series. So current temperature, SOC and age of the cell is similar to other cells. The battery pack voltage is calculated by using a voltage measurement block, and this measurement block is connected across the battery pack i.e., first cell positive terminal connected to positive terminal of voltage measurement block and last cell negative terminal connected to negative terminal of voltage measurement block. Also, by using constant blocks, it provides ambient temperature to all cells.

Signal builder block :Signal builder block helps you to build signal of your own. It helps you to create and generate interchangeble signal .

Controlled Current Source:The controlled current source block converts the Simulink input signal into an equivalent current source. The generated current is driven by the input signal of the block. The positive current direction is as shown by the arrow in the black icon. We can initialize the controlled current source block input must be connected to a signal starting as a sinusoidal or DC waveform corresponding to the initial values. For this model we have given signal builder as input.

Generic Battery:The battery block implements a generic dynamic model represents most popular types of rechargeable batteries. For this model enables the temperature effects and aging effects options, so cell nominal voltage is 7.2 V capacity 5.4Ah, initial SOC 0%, in aging section aging model aging sample time is 20 sec, aging characteristics at cell ambient temperature of cell 25°C and l the other parameter are default values. So now our battery pack voltage is 7.2V and capacity is 5.4 A.

Simulation Result:

Case 1: Ambient temperature 25°C and charge-discharge current 5.4Ah

Case 2: Ambient temperature 45°C and charge-discharge current 5.4Ah

In this case the battery pack SOC and voltage is same as case 1 but this ambient temperature adverse effect replicates in the age of cycle and of course cell temperature also increases.

case 3: Ambient temperature 45°C and decrease in maximum capacity 3Ah

Conclusion:When ambient temperature increases then obviously cell temperature is increased also this ambient temperature adverse effect reflects on the age of the battery pack and vice versa.
Similarly, when we decrease (max capacity)C rate then it shows favorable and unfavorable effects on the age, SOC, temperature and voltage of the battery pack