Project 2 Thermal modeling of battery pack

Answer--

 

 circuit construction and working  -

in this circuit we use li-ion cell 1 to 10, temperature sensors, ambient temp block, state of charge estimation  scope, charge-discharge profile given to circuit, from & goto block Matlab Simulink

Cell 01 to O4 Subsystem:

This block consists of a capacitance value © table which depends on external physical signal inputs SOC and T. It is assumed that the capacitance value is slowly varying with time, and hence the equation i = C*dv/it holds.

Resistance value (R) table which depends on external physical signal inputs SOC and T.

Voltage value (EM) which implements the cell's main branch voltage source, and determines values for capacity (C) and state of charge (SOC). The
defining equations depend on cell temperature, T.

 

 

 

 the output of one cell is connected with the SOC estimation whereas another output is connected with the AC source for the cyclic charge/discharge profile.
The peak amplitudes are set to 50 A for cyclic charge and discharge. A basic parameter of AC source is as

 other blocks which are used in lithium-ion battery packs are as:

 Temperature Source:

The Temperature Sensor block represents an ideal temperature sensor, that is, a device that determines the temperature differential measured between two points without drawing any heat.

Connections A and B are thermal conserving ports that connect to the two points where the temperature is being monitored. Port T is a physical signal port that outputs the temperature differential value.

The block's positive direction is from port A to port B. The measured temperature is determined as T = T_A – T_B.

This block represents an ideal energy source in a thermal network that can maintain a constant absolute temperature at the port regardless of the heat flow rate.
This block is used for ambient temperature which we can set and check results.

 Heat Transfer:

This block models heat transfer in a thermal network by convection due to fluid motion. The rate of heat transfer is proportional to the temperature difference, heat transfer coefficient, and surface area in contact with the fluid.

this used for 1-4 cells and 6-10 cell

•  From block and Goto blocks 

The Goto block passes its input to its corresponding From blocks. The input can be a real- or complex-valued signal or vector of any data type. From and Goto blocks allow you to pass a signal from one block to another without actually connecting them.

The From block accepts a signal from a corresponding Goto block, then passes it as output. The data type of the output is the same as that of the input from the Goto block. From and Goto blocks allow you to pass a signal from one block to another without actually connecting them.

• state of charge estimation 

The Coulomb counting method measures the discharging current of a battery and integrates the discharging current over time to estimate SOC

This subsystem takes current as input and gives the battery SOC % as output. A  current sensor block is used and connected for soc estimation 

This ckt estimates the battery SOC % using the coulomb counting method. It takes current as the input and gives SOC% as the output. The initial SOC of the battery is assumed to be 100% (1)

example shows how to simulate a battery pack consisting of multiple series-connected cells efficiently. It also shows how a fault can be introduced into one of the cells to see the impact on battery performance and cell temperatures

 results  

a) result for 26.85°C

b)result for 36.85°C

c)result for 50.85°C