Week 9 Challenge

Complete the energy management strategy model with battery, UC and fuel cell for the positive power and distribute the power demand among these components. Set simulation stop time to 598 sec.

The output of the model should be the power request from UC, fuel cell and battery.

A.

The flowchart below explains how the model is developed in Simulink.

There are three inputs to the EMS,

• Power Demand (Watts)
• Battery SoC (0 to 1)
• UC SoC (0 to 1)

The algorithm is built in such a way that,

• Any input between 23000 and 55000 Watts come under Fuel Cell Power
• For any input < 23000 Watts
  • IF (battery_SoC > 0.3)
    • Battery provides Power demand
  • ELSE IF (Power Demand + Battery Charging Power) < 55000
    • Fuel cell provides (Power Demand + Battery Charging Power)
  • ELSE
    • Fuel Cell provides Power demand

• For any input > 55000 Watts
  • IF (UC_SoC > 0.3)
    • UC + FC provides Power demand
  • ELSE IF (battery_SoC > 0.3)
    • Battery + FC provides Power demand
  • ELSE
    • FC provides Power demand

Battery Charging power is estimated to be 145 watts for a 12V battery (12.9V * 11.25A ~ 145 W)

The backing power provided by Fuel cell whenever power exceeds 55kW is calculated using a separate subsystem.

The results are shown below.

Here, it can be seen that, whenever the power demand is very high (>55kW), 55kW power will be taken by the FC and the rest will be taken by the UC. Whenever the power demand is really less (<23kW), whole demand is met by battery alone.

Given below are the SoC values of ultracapacitor and battery that are given as input to the system. Here, neither of the values go less than 0.3. The difference in performance when the SoCs go below 0.3 can be duly checked and analyzed using the system.