FCEV_Challenge_9

Question :-

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.

Aim)The main aim is prepare the Energy management strategy model with battery, UC and fuel cell for the positive power in Simulink.

Answer)

Energy Management Strategy:-

The vehicle industry is experiencing a technological revolution in the powertrains of vehicles. So, the hybrid electric vehicle HEV is an effective choice to solve the problems of the low energy density of a power battery and the short driving distance of an electric vehicle.

Here Different configurations of HEVs have different control strategies production costs and applicable conditions.But however, for any configuration the ultimate goal is to achieve the comprehensive optimization of the efficiency of the engine and the motor so as to improve the vehicles performance parameters such as economy emissions and durability.

The procedure of realizing the goal is commonly called an Energy Management Strategy (EMS).

The act of load sharing is mainly implemented through the EMS systems.But According to the power demand of vehicle the power request from sources distributed among different energy giving sources like ultracapacitors batteries and fuel cells based on their power demand capability.

EMS system Power Flow Process:-

The EMS system power flow Process will be explained by using the Below flow chart.

Explanantion :-

Here The fuel cells having a range of operating condition to produce the power needed for propulsion.

Then we are taking fuel cell with have capability to produce power in the range between minimum of 23KW to maximum of 72KW.But, for better efficiency of fuel cell power usage, it is derived that fuel cells will operate at maximum efficiency in moderate power generation area as seen from polarization curve.

So, we are considering lesser power production level for maximum fuel cell power generation as 55KW.

The Batteries are preferred to operate in lower power demand conditions and ultracapacitors are preferred to operate in peak power demands.

So, we are getting the final power sharing between three components as

1. From 0 to 23 KW is drawn from battery unit based on its SOC condition.
2. Above 23KW to 55KW will be drawn from fuel cell power.
3. And above 55KW will be drawn from ultracapacitors based on its SOC condition.

So, If SOC of UC is not enough to supply required power demand in that case the power is drawn from battery as battery backup.

If SOC of battery and UC are not enough to supply power demand in that case alternate source is only fuel cell.

Here the Power is drawn from fuel cell as fuel cell backup.

But at these operating conditions the overall efficiency of vehicle is reduced as fuel cell can’t support with full efficiency for peak power demands and lesser power demands.

Condition table :-

Simulink Model :-

The Simulink model of the Emnergy Management stratagy will be as followes.

Procedure:-

The Positive power Subssystemis as followes .

The Positive power subsystem consists as total 3 power sources and those are as follows:-

Source@1)

Fuel cell source :-

Here In propulsion subsystem positive power the power demand is tested for three components UC ,Fuel cell and Battery based on their operating ranges using interval test block.

For fuel cell test operating range set as from above 23KW to 55KW.

The Fuel cell power back is in Simulink model is given as

The range can be set by using the Interval test block with following parameters.

The Fuel Cell Backupsubsystem consists the following block.

Source@2)

Ultra capacitor Source :-

The ultra capacitior source will model in simulink as follows.

This ultracapacitor consis a two test

TEST@1) US high test:

This test is the power demand will be limit to 55KW to Inf

this can be set to the bock i=using the intrval test blcok with following parameters.

TEST@12) UC Low test:

This test is the power demand will be limit to 0KW to 22KW.

Here If the condition is true then the output of this block.Then This output is checked with a switch block as input where,
if the input is 1 then this positive power is again checked for UC_SOC condition .If the SOC of UC is >= its minimum value then this positive power is considered as ultracapacitor power request. For battery test operating range set as from 0 to 23KW

This can be set using the intrval test blcok with following parameters.

Here If the condition is true then the output of this block is 1 So This output is checked with a switch block as input where if the input is 1 then this positive power is considered as fuel cell power request.For ultracapacitor test operating range set as from above 55KW.

Source@3)

Battery Pack Source:-

This source range of power demand between 0KW to 23KW

The Battery source will model in simulink as follows.

Battery pack sy=ubsystem is as followes:-

If the condition is true then the output of this block.Then This output is checked with a switch block as input where,
if the input is 1 then this positive power is again checked for battery SOC condition So If the SOC of battery is >= its minimum value then this positive power is considered as battery power request.

Output :-

The results can be plotted by using the Scope block as follos:-

From the Above graph

>>the top plot is for input signal by using the signal builder block.

The 2nd plot is for ultra capacitor power

The 3rd plot is for Fuel cell power

The 4th plot is for battery power.

In this Situation the ultracapacitor power is usefull only while driving.Both Fc and Battery power sourcs are failed to get the send the propulsion power to the vehicle blow the required SOC %.

hence this situation only used the Ultracapacitor Power Source for traction purpose.

Results :-

The required modelFor positive power Energy Management Stratagy in simulink is created and Successfully Run with simulation time od 598 sec.

------------------------------------------------------------------------------------------------------------------------------

CONCLUSION:- ALL REQUIREMENTS ARE MET

------------------------------------------------------------------------------------------------------------------------

(THE END)