Week 8 Challenge

Load the UC parameter file. Complete the Ultracapacitor model. Set simulation stop time to 598 sec.

The model output should give, current, SOC and Voltage as output

answer:

The model for ultracapacitors is displayed below. The ultracapacitor uses the power as its input. The charge calculation, SOC estimation, open circuit voltage calculation, and current calculation make up the ultracapacitor subsystem.the diagram of the ultracapacitor subsystem block has the state of charge (SOC) computation is displayed in the highlighted portion. The formula below is used to determine the SOC.

soc = (UC current * UC efficiency)/charge dt

Where. efficiency is the Coulomb efficiency of tha ultracapacitor.

Q is the electric quantity and I is the current from the ultracapacitor.

uc current caculation

The calculation as it stands is displayed below. The internal resistance of the UC and the connecting cables are primarily responsible for the system's lumped resistance, which is taken into account while determining the current equation. The equation as it stands is shown below. One can compute the ultracapacitor current by using:

UC Current= ((SOC*V_max)-sqrt((SOC*V_max)^2-4*R*puc*eff)/2*R))

Where,

R is the lumped resistance,

Vmax is the maximum voltage of the UC

n is the efficiency during the charge/discharge cycle.

open circuit voltage

The computation for Open Circuit Voltage (OCV) is displayed below. The following is the OCV formula:

OCV = intergal of ( i/C ) dt

uc charge

Below is a diagram of the charge Q subsystem. The sum of the maximum voltage and capacitance yields the charge. The fee calculation looks like this:

Charge = V_max*c

UC Voltage

The voltage block subsystem is shown below. The voltage formula is as follow,

Voltage = (SOC*V_max) - (I*R)

The resistance, capacitance and maximum voltage value is given below. Type these values in the matlab command window. R=0.10;
C=83;
V_Max=750;

Result:

The figure below shows the result for ultracapacitor SOC, ultracapacitor voltage and ultracapacitor current. The simulation stop time is 528 seconds.