Module Title & Code

WM993-15, Modelling and Simulation of Systems

Component Type

Written Report

Assessment Title

Modelling and Simulation of Electric Vehicles- 2^nd Resit Assessment

Weighting (%)

60%

Coursework Brief

You are a powertrain integration modelling specialist at an automotive powertrain development company. Various engineering teams have designed their components and subsystems and provided you with their characteristics.

As a powertrain integration engineer, you are tasked with conducting a model-based analysis to predict the primary performance and energy consumption characteristics of the proposed vehicle using computer-based simulations.

The characteristics of the vehicle and its main components are provided in the table below.

Table 1 Vehicle and powertrain specification

1 Model development

In the model development, you are required to create the architecture of the entire model and discuss each individual subsystem and the methods you have used to model them. In this section, you are mainly tasked with development of the powertrain model.

1.1 Model Architecture (6 marks) [LO5]

Provide a physical architecture (not a Simulink/block diagram) of the vehicle powertrain system at the system level. Identify the subsystems, connections, and data flow between the subsystems. You should discuss the cause-and-effect processes in this section. Justify why you believe this approach to the architecture is appropriate for the aim of modelling.

1.2 Vehicle dynamics (8 marks) [LO1]

Briefly discuss the vehicle dynamics model and the governing equations. Include schematics of the vehicle dynamics and illustrate the relevant forces.

1.3 Tyre and transmission (4 marks) [LO1]

Briefly discuss the tyre and transmission model and the relevant governing equations.

1.4 Electric machine and drive

1.4.1 Torque envelope (6 marks) [LO1]

Present the torque envelope map of the electric machine

1.4.2 Modeling method (8 marks) [LO2]

Briefly discuss the method you have used to model the electric machine and drive and calculate torque and the DC current. You should address the reasons why you have chosen this method among the various available modelling approaches for electric machines and drives. You also need to show the block diagram of the model you have developed for the ED. For the electric machine, you can assume a 90% efficiency.

1.5 Battery

1.5.1 Battery pack voltage, current and capacity (10 marks) [LO1]

Determine the battery pack nominal voltage, the battery pack nominal charge capacity (in Ah), caloric capacity of the battery pack (in kWh), and the maximum continuous discharge current of the battery pack.

1.5.2 Open circuit voltage (6 marks) [LO1]

Plot the open circuit voltage (OCV) of the battery pack as a function of battery pack SoC.

1.5.3 Internal resistance (6 marks) [LO1]

Calculate the internal resistance of the battery pack based on the internal resistance of a single cell given in table 1.

1.5.4 Battery modeling (8 marks) [LO2]

Discuss the governing equations you used for modelling and mention any assumptions made for simplification. You can also show the block diagram of the battery modelling.

2 Model simulation 

In the model simulation, you are required to predict the vehicle attributes, performance and energy consumption rate of the electric vehicle using the model you have already developed. In this section, you will focus primarily on deriving results from the simulation, illustrating the results using appropriate methods, and analysing the outcomes.

2.1 Full load simulation

Using the full-load simulation, determine the following characteristics. For each, please support your results with appropriate graphs.

2.1.1 Model setup (6 marks) [LO2]

Report how you set up the model to run under full-load conditions. You must describe the inputs you considered for the model to simulate the vehicle under full load. Also, mention the type of solver you have used in MATLAB/Simulink.

2.1.2 Maximum speed (4 marks) [LO5]

For this section, show the vehicle speed (in km/h) for 150 sec. Determine the maximum speed.

2.1.3 0-100 km acceleration time (4 marks) [LO5]

For this section, determine the acceleration time and support your findings with appropriate graphs. Use an appropriate time scale to show the acceleration on the graph.

2.1.4 Maximum current (4 marks) [LO5]

For this section, determine the maximum current drawn from the battery and support your findings with appropriate graphs. To show the current signal, run the model for 100 sec.

2.1.5 Range of the vehicle with the maximum speed in km (10 marks) [LO5]

Determine the range of the vehicle (in km) when it cruises at maximum speed. For this calculation, assume the range is defined as the distance travelled when the SoC decreases from 100% to 10%. You must display the SoC as a function of time.

2.1.6 The energy consumption rate in kWh/100km (10 marks) [LO5]

Calculate the energy consumed in kWh to travel the range found in the previous question. Based on this, please determine the energy consumption rate in kWh per 100 km using the results from the full load simulation.