Week-4 Challenge WOT Condition Part-2

1)Aim:

To describe the difference between mapped and dynamic model of engine, motor and generator.

Description:

Mapped Model:

Mapped model is a model used where the model is designed not in practical cases, but modeled by entering the interested values in the lookup table for obtaining the Simulink result.

Dynamic Model:

Dynamic model used when the actual result of the component is required and not with the interested values.

Engine

Mapped model	Dynamic model
· Mapped engines represent macro engine behavior as a set of lookup tables (brake torque, fuel flow, air mass flow, exhaust temperature, efficiency, and emissions) as functions of commanded load and measured engine speed.	· Dynamic engines decompose engine behavior into individual component models that account for engine dynamics, most notably intake airflow and turbocharger dynamics.
· Mapped engine models are suitable for analysis and design activities that do not require engine subsystem dynamic characteristics, for example, in engine and transmission powertrain matching analysis for fuel economy, emissions, and performance tradeoffs.	· Dynamic engine models are suitable for designing control, estimator, and diagnostic algorithms that depend on dynamic subsystem states, for example, in closed-loop AFR control algorithm development.

Motor

· Motor specifications are entered using the lookup tables before simulating the result. · Specification are rpm, maximum efficiency, and losses.

· Here, the actual details /specifications of the motor is considered and result is simulated.

Generator

· Battery torque, Battery Current and others are considered in the lookup table for simulating the model for generator.

· Same as motor and engine, the actual details or specifications of the generator are taken into account and the result is simulated.

From the reference application of Electric Vehicle, We can see the mapped and Dynamic model of motor.

Mapped Motor:

The above screenshot shows the Mapped model of Electric Vehicle.

It Implements a mapped motor and drive electronics operating in torque-control mode. Specify electrical torque range with a torque-speed envelope or maximum motor power and torque. Output torque tracks a torque reference demand and includes a motor and drive response time constant. Specify electrical losses as a single operating point that estimates loss across the operating range, measured loss, or measured efficiency.

Dynamic Motor:

The screenshot shows the Dynamic model of Electric Vehicle. For Dynamic model, motor components such as inverter, phase controller, feedback circuits are modeled.

Changing from Mapped to dynamic model:

If model needs to be changed from mapped to dynamic, click the Variant Manager and select the Dynamic option. Right click on the Dynamic motor and select the Set as label Mode Active Choice.

2)Aim:

To calculate miles per gallon for the model.

Description:

The input given for calculating miles per gallon are Vehicle speed, Battery power and Fuel flow.

The Highlighted diagram provides the calculation model for miles per gallon.

We know that 1 US liquid gallon equal to 3.78 litres. i.e 264.17 gallon equals 1000 litres.

The Fuel Efficiency is calculated by using battery output, Fuel output and Vehicle speed.

3)Aim:

To Run the HEV ReferenceApplication with WOT drive cycle.

Description:

The Simulated model of the HEV Reference Application is shown below.

Here the Drive Cycle source changed to WOT(Wide Open Throttle).

For Grade =0 and wind velocity=0,

For Grade=5 and wind velocity=10,

From the above graph, verified that,

Plot 1: Shows the analysis between Target velocity Vs Actual velocity.

Plot 2: Provides the analysis between Engine speed and Motor Speed.

Plot 3: Shows comparison between Engine torque, motor torque and generator torque.

Plot 4: Power produced by battery.

Plot 5: Battery’s State of Charge.

Plot 6: Fuel efficiency denoted in Miles per Gallon.

Results:

By comparing the Two graph plots, increase in grade and wind velocity, results in

• Peak velocity reduces as gradient and aerodynamic forces becomes dominant.
• Fuel economy also reduces as distance travelled reduces.
• Deceleration time reduces so that regeneration capacity also affects.

4) Aim:

To compare the simulated results of hybrid and pure electric powertrains with same parameters.

Model Configurations:

EV:

HEV:

Simulink Model:

Result:

By Keeping the Grade and Wind velocity common for both the EV and HEV models, below graphs are plotted.

HEV:

Ev:

From the above plots, It has been found that,

• Pure Electric Vehicle have low velocity compared to Hybrid Electric Vehicle.
• Deceleration time is low for HEV compared to EV.
• Motor speed is also less than HEV, but path tracings is same as that of HEV.
• Motor Torque of EV is almost Similar to HEV.
• Fuel Economy is more for EV compared to that HEV Due to more number of moving parts in HEV Compared to EV.