Charging piles are charging facilities for electric vehicles, and their functions are similar to those of gas pumps in gas stations.
1) According to different power supply methods, they can be divided into AC charging piles and DC charging piles.
AC charging piles generally have low current, small pile bodies, and flexible installation;
DC charging piles generally have high current, larger charging capacity in a short period of time, larger pile bodies, and large occupied area (heat dissipation).
2) According to different installation methods, they are mainly divided into vertical charging piles and wall-mounted charging piles.
Vertical charging piles do not need to be against the wall and are suitable for outdoor parking spaces and community parking spaces; while wall-mounted charging piles must be fixed on the wall and are suitable for indoor and underground parking spaces.
3) According to different installation scenarios, they are mainly divided into public charging piles, dedicated charging piles, and self-use charging piles.
Public charging piles are charging piles built in public parking lots (garages) combined with parking spaces to provide public charging services for social vehicles.
Dedicated charging piles are charging piles used by internal personnel of the construction unit (enterprise) in its own parking lot (garage).
Self-use charging piles are charging piles built in personal parking spaces (garages) to provide charging for private users. Charging piles are generally built in conjunction with parking spaces in parking lots (garages). The protection level of charging piles installed outdoors should not be lower than IP54. The protection level of charging piles installed indoors should not be lower than IP32.
4) According to different charging interfaces, they are mainly divided into one pile and one charge and one pile and multiple charges.
One pile and one charge means that a charging pile has only one charging interface. At present, charging piles on the market are mainly one pile and one charge.
One pile and multiple charges, that is, group charging, means that a charging pile has multiple charging interfaces. In large parking lots such as bus parking lots, group charging piles are required to support the charging of multiple electric vehicles simultaneously, which not only speeds up charging efficiency but also saves labor costs.
The general structural block diagram of pure electric vehicle charging is shown in the figure below. The working principle is: AC power is input from the three-phase power grid, converted into DC power by a bridge uncontrolled rectifier circuit, and sent to a high-frequency DC-DC power converter after filtering by an LCR circuit. The power converter outputs the required DC voltage after direct conversion, and charges the electric vehicle battery after output filtering. Charging can choose four modes: fixed power, fixed time, fixed amount, and automatic (until full).。
The main structure of the charging pile includes the pile body, charging module, display screen, connecting cable, account management module, safety protection device and other parts. The structural design and quality of these parts directly affect the service life and safety of the charging pile.
1) Pile body
The pile body structure of the charging pile is usually made of steel, aluminum alloy and other materials, with strong durability and stability.
2) Charging module
The charging module is the core part of the charging pile, including components such as charger, controller, and power supply. The charger is the main component of the charging pile, responsible for converting electrical energy into the electrical energy required by the electric vehicle. The controller is responsible for controlling the working status of the charger and various parameters during the charging process to ensure the safety and stability of the charging process. The power supply provides power to the charging module.
3) Display screen
The display screen of the charging pile is usually used to display the status, charging progress, charging cost and other information of the charging pile. The types and sizes of display screens are different. Some charging piles are also equipped with touch screens for user convenience, human-computer interaction, and to meet the personalized needs of different types of users.
4) Account management module
The account management module calculates the consumption amount based on the current real-time electricity price and consumed electricity data, collects fees, and prints bills. The controller and embedded printer need to work together to complete the accounting management task. The charging pile adopts a ladder-shaped electricity price policy. The controller calculates the consumption amount this time and completes the charge. The printer communicates with the controller, and the controller sends the consumption information to the printer to print the bill details of this charging.
5) Connection cable
The connection cable is the bridge between the charging pile and the electric vehicle, responsible for transmitting power and data. The quality and length of the connection cable directly affect the charging efficiency and safety. Some high-end charging piles are also equipped with automatic reels for user convenience.
6) Safety protection device
The safety protection devices of the charging pile include leakage protection, overcurrent protection, overvoltage protection, etc. These devices can effectively protect the safety of the charging pile and electric vehicles.
There are three main charging methods for charging piles, namely fast charging, slow charging, and wireless charging.
1) Slow charging
Slow charging is a more commonly used charging method. For new energy electric vehicle charging piles, it is connected to the on-board charger, which mainly converts low-power AC into DC, which is often called AC-DC conversion. The charging power is generally 3kw or 7kw. The reason is that the power battery can only be charged with DC. In addition, the slow charging interface of new energy electric vehicle charging piles generally has 5 holes.
2) Fast charging
Fast charging is a charging method that everyone likes, after all, it saves time. Fast charging is to connect the AC-DC converter to the new energy electric vehicle charging pile, and the output of the charging gun becomes high-power direct current. Moreover, the charging current of the interface is generally very large, the battery cell is much thicker than the slow charging, and the number of holes of the battery cell is also much more. The fast charging interface of the new energy electric vehicle charging pile generally has 7 holes.
As an important infrastructure for new energy vehicles, charging piles have many advantages. These advantages not only promote the development of new energy vehicles, but also have a positive impact on society and the environment. The following are the main advantages of charging piles:
1. Environmental protection and sustainable development
• Low emission or zero emission: New energy vehicles use charging piles to charge, and almost no harmful gases are emitted during driving, which significantly improves air quality. In particular, charging piles powered by renewable energy (such as solar energy and wind energy) can further reduce the user’s carbon footprint, reduce urban noise pollution, and promote green travel1.
2. Driven by economic benefits
• Create employment opportunities: The development of the charging pile industry, including production, installation and maintenance, has created a large number of jobs.
• Reduce travel costs: The cost of using electric vehicles is lower than that of traditional vehicles, and the charging fee is more competitive. Long-term use can save car owners a lot of fuel costs.
• Promote tourism and local economy: The construction of charging piles in urban scenic spots, hotels and other places has attracted new energy vehicle owners and promoted the development of local tourism and economy.
3. Convenient and intelligent experience
• Convenient query: Modern charging piles are integrated with high-tech functions. Users can query the location, usage status and cost information of nearby charging piles in real time through mobile applications, realizing “charging without worry”.
• Fast charging technology: Future smart charging technologies, such as ultra-fast charging and wireless charging, will greatly shorten charging time and improve vehicle efficiency1.
4. Promote social responsibility and environmental awareness
• Spread environmental protection concepts: The construction of charging piles is not only a reflection of technological development, but also a manifestation of social responsibility. Through the construction of charging piles, enterprises and governments spread low-carbon and environmental protection concepts and promote the popularization of new energy vehicles.
5. Enhanced safety
• Multiple protections: Electric vehicle charging piles have the function of automatically detecting the battery status to avoid safety hazards such as overcharging and over-discharging. At the same time, the charging piles have multiple protection functions such as overload protection and overvoltage protection to ensure the safety and reliability of the charging process.
6. Promote energy transformation
• Reduce fossil fuel dependence: The construction of charging piles helps to reduce dependence on traditional fossil fuels and promote the optimization and transformation of the energy structure. The popularization of new energy vehicles and the construction of charging piles are important ways to achieve this goal.
7. Drive the development of related industries
• Industrial chain prosperity: The construction of charging piles has driven the development of related industries such as charging equipment, batteries, and smart grids, forming a new economic growth point. With the expansion of the new energy vehicle market, the charging pile industry will usher in a broader development space.
In summary, the advantages of charging piles are not only reflected in improving the convenience of new energy vehicles, but also in their positive contributions to environmental protection, economic benefits, energy transformation and social responsibility. With the continuous advancement of technology, charging piles have great potential for future development and will play an increasingly important role in promoting green travel and sustainable development.
