Table of contents
Abstract 1
Keywords 1
Abstract 2
Keywords: electric vehicle, AC charging spot, battery management system, Lab VIEW, CAN trunk 3
Contents I
1 Introduction 2
1.1 Background and significance of the subject research 2
1.2 Development status of electric vehicle charging facilities at home and abroad 3
1.2 .1 Development status of foreign electric vehicle charging facilities 3
1.2.2 Development status of domestic electric vehicle charging facilities 4
1.3 Types of AC charging piles 5
1.4 Discussion on power battery charging methods 6
2 Design analysis of AC charging piles 8
2.1 Function analysis of charging piles 8
2.1. 1 Working process principle 8
2.1.2 Intelligent charging function 8
2.2 Charging pile structure analysis 8
2.3 AC charging pile main material analysis 9
3 AC charging pile hardware design 10
3.1 Motherboard hardware structure introduction 11
3.1.1 MCU circuit 11
3.1.2 System Power supply circuit 12
3.1.3 Voltage and current signal conditioning circuit 15
3.2 AC charging pile charging plug and control guiding circuit 16
3.2.1 AC charging pile charging plug 16
3.2.2 Control guiding circuit 17
3.3 Hardware interface 18
3.3.1 SP3739 serial port expansion circuit 18
3.3.2 Peripheral equipment expansion circuit 20
3.3.3 CAN interface circuit 21
3.4 Emergency stop button design 22
3.5 Summary of this chapter 22
4 AC charging pile system software design 23
4.1 Lower computer software overall architecture 23
4.1. 1 Human-computer interaction module 24
4.1.2 Electric energy metering module 25
4.1.3 CAN bus communication interface module of AC charging pile 25
4.1.4 Fault alarm module 26
4.2 Upper computer system software architecture 27
4.2.1 Lab VIEW introduction 27
4.2.2 Background management system design 28
4.3 Summary of this chapter 29
5 Communication protocol between AC charging pile and background management system 30
5.1 CAN bus introduction 30
5.2 CAN bus access mechanism 31
5.3 Charging station system CAN network establishment 31
5.4 Charging station system CAN bus communication protocol Realization 32
5.5 CAN network test of charging station 34
5.6 Summary of this chapter 34
6 Research on intelligent charging strategy of AC charging pile 36
6.1 Battery charging termination control method 36
6.2 Charging based on standard charging plug 36
6.3 Charging based on charging plug with CAN bus 37
6.3.1 Realization of intelligent Charging 37
6.4 Chapter Summary 38
7 Conclusions and Prospects 39
7.1 Conclusions 39
7.2 Prospects 39
References 41
Acknowledgments 44
2 AC Charging Pile Design Analysis
2.1 Charging Pile Function Analysis
2.1.1 Working Process
The charging pile design in this paper has a complete touch screen, and the characters displayed on the display Very clear and full, with high contrast, so it can be read without relying on ambient light sources. The charging pile is stylish and exquisite, equipped with a radio frequency card reader and a special electric vehicle charging card. After the owner of the electric vehicle connects the charging plug, he can swipe the card in the sensing area of the card reader, and then the screen will display the account balance and charging mode selection, and finally the user chooses the appropriate charging method to charge. The card swiping operation method is the main process of the charging pile card reader. The process is mainly divided into card swiping start-selection mode-charging billing-card swiping checkout, and the steps are carried out in sequence. Calculate the electricity bill by reading the electricity data of the electronic energy meter and charging electricity price, complete the user's consumption calculation, and automatically deduct it from the user card at the end of the card checkout [8].
2.1.2 Smart charging function
The National Development and Reform Commission notified that China's residents will implement three-tiered electricity prices in the future. According to a test by a research institute in the United States, our electricity costs will be about 30% higher without reasonable planning. However, with the widespread popularization of electric vehicles, our future electricity consumption will be greater. If most users choose to charge during the daytime or busy hours of peak electricity consumption under normal circumstances, then our electricity bills will increase. Much higher. For this electricity price fluctuation situation, this charging pile design scheme will use an intelligent charging system to help people better realize the management and allocation of electric vehicle charging. The smart chip installed in it can obtain the electricity price information of the power department anytime and anywhere, and users can choose the most suitable and economical time to charge their electric vehicles according to this information, which avoids peak hours and saves expenses.
2.2 Structural Analysis of Charging Pile
According to the requirements of ergonomics, the charging pile designed in this project is 1295.79mm high and 399.78mm wide, with a delicate shape and a small footprint. People's arms are operated on the charging pile in the most comfortable state, and at the same time, people's head can fully see the content on the screen with a slight tilt of the main line of sight, because the shape of the screen is slope-like. This charging column is a floor-standing type. The host structure is mainly composed of an integrated full touch screen, a card reader, a charging socket, a charging gun, a transformer, and a waterproof base. The screen is a transparent acrylic board. The design of the charging gun is also very user-friendly. When the charging gun is used up, just put it back into the charging socket, and the connecting line will automatically retract to the bottom of the charging pile, which is convenient and neat.
Figure 2.1 Dimensional drawing of electric vehicle charging pile
