Graduation Design (Dissertation) of Wuhan University of Technology

Overall Design of Small Electric Scooter

College: International Education College

Specialty amp; Class: Automobile GJ1303

Student name: Yusi Cheng

Tutor: Wei Guo

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Abstract

Under the global petrochemical energy depletion, the world began to find suitable new energy products to optimize national energy structure and face the challenges of energy and environmental crisis. This demand provides a good opportunity for new energy vehicles, especially pure electric vehicles to develop in market.

According to the market demand for pure electric vehicles and advantages of pure electric vehicles in reducing traffic congestion, saving energy and decreasing emission, this paper chooses a micro pure electric ferry with a normal travel abilities in the city as a design object. Reference to the market mature small car products’ vehicle parameters and layout and the national technical requirements of pure electric vehicles, this paper has determined dynamic and economic requirements of the micro pure electric vehicle with front-wheel-drive layout.

On the basis of the design process of electric vehicle drive system, this paper completes the design of micro pure electric vehicle driving motor selection and matching considering the existing pure electric vehicle parameters and dynamic, economic indicators. Next, this paper completes the drive system design of the electric vehicle with the corresponding relationship between the maximum speed of the motor and the maximum vehicle speed and the corresponding relationship between the motor output torque and vehicle dynamic performance. Finally, you can successfully establish the relationship between the energy requirements of the motor and the battery power, and further complete the power battery selection and matching with the completion of the transmission system design.

Established drive motor system and power battery system parameters can be used into the theoretical formula for electric vehicle performance checking. Due to determined vehicle design parameters, a data model of the micro pure electric vehicle can be established. Using the ADVISOR software to simulate dynamic and economic performances of the electric vehicle in the New York city road condition and in the constant speed 50km / h condition, the dynamic performance and the economic performance of the simulation are compared with results of the theoretical calculation to evaluate the scientific features and feasibility of the micro vehicle design.

Key Words：micro pure electric scooter；vehicle overall design；motor system matching; battery system matching; simulation with ADVISOR

Contents

I INTRODUCTION 1

1.1 Foreword 1

1.2 Electric Vehicle Research Status in Home and Abroad 2

1.3 The Main Research Content of the Paper 4

II DETERMINATIONS OF SMALL PURE ELECTRIC VEHICLE PARAMETERS AND LAYOUT 6

2.1 Determination of the Small Pure Electric Vehicle Parameters 6

2.1.1 Small Pure Electric Vehicle’s Technical Parameters 6

2.1.2 Determination of Calculating Parameters of Drive System 6

2.2 Determination of Small Pure Electric Vehicle Layout 8

2.3 Small Electric Scooter’s Type Selection and Model Establishment 9

2.4 Summary 10

III PURE ELECTRIC VEHICLE’S POWER SYSTEM MATCHING 12

3.1 Evaluation Index of Electric Vehicle’s Electric Power System 12

3.2 Matching Process and Dynamic Analysis of Small Electric Vehicle Power System 13

3.2.1 Small Electric Vehicle Power System Matching Process 13

3.2.2 Analysis of the Motion Equation of Small Electric Vehicles 14

3.2.3 Determination of Kinematic Parameters of Small Electric Vehicles 16

3.3 Summary 16

IV SMALL PURE ELECTRIC VEHICLE DRIVE MOTOR SYSTEM MATCHING 18

4.1 Electric Motors Commonly Used in Electric Vehicles 18

4.2 Drive Motor System Matching 20

4.2.1 Motor Rated Power Matching 21

4.2.2 Motor Peak Power Matching 21

4.2.3 Motor Torque Matching 21

4.3 Electric Vehicle Transmission Matching 23

4.3.1 Use Maximum Speed and Motor Maximum Speed to Determine the Upper Limit of the Transmission Ratio 23