Four dimensions of science popularization! For Charging station, get everything!

As the supporting infrastructure of electric vehicles, the Charging station is an indispensable part to provide charging services for electric vehicles. Today’s article will give you the basic knowledge and working principle of new energy Charging station in science popularization. Let’s learn it together!

Classification of Charging station

The Charging station is the charging facility of electric vehicles, and its function is similar to the Gasoline pump in the gas station.

1) According to different power supply modes, it can be divided into AC Charging station and DC Charging station.

AC Charging station generally has small current, small pile body and flexible installation;

However, the DC Charging station is generally characterized by high current, larger charging capacity in a short time, larger pile body and large occupation area (heat dissipation).

2) According to different installation methods, it is mainly divided into vertical Charging station and wall mounted Charging station.

The vertical Charging station does not need to lean against the wall, and is suitable for outdoor parking spaces and residential parking spaces; The wall mounted Charging station must be fixed by the wall, which is suitable for indoor and underground parking spaces.

3) According to different installation scenarios, it is mainly divided into public Charging station, special Charging station and self use Charging station.

The public Charging station is a Charging station built in the public parking lot (garage) combined with parking spaces to provide public charging services for social vehicles.

The special Charging station is a Charging station used by the internal personnel of the construction unit (enterprise) for its own parking lot (garage).

Self use Charging station is a Charging station built in a private parking space (garage) to provide charging for private users. The Charging station is generally constructed in combination with the parking space of the parking lot (garage). The protection grade of Charging station installed outdoors shall not be lower than IP54. The protection level of Charging station installed indoors shall not be lower than IP32.

4) According to different charging interfaces, it is mainly divided into one pile for one charging and one pile for multiple charging.

One charge per pile means that a Charging station has only one charging interface. At present, the Charging station in the market is mainly one charging pile.

Multi charging in one pile, namely group charging, means that one Charging station has multiple charging interfaces. In large parking lots such as bus parking lots, group charging Charging station are needed to synchronously support the charging of multiple electric vehicles, which not only speeds up the charging efficiency, but also saves labor costs.

Working principle of Charging station

The general structure diagram of pure electric vehicle charging is shown in the following figure. The working principle is: AC power is input from the three-phase power grid, and then it is converted into DC power through the bridge uncontrolled rectifier circuit. After being filtered by the LCR circuit, it is sent to the high-frequency DC-DC power converter. The power converter outputs the required DC voltage through the direct to direct conversion, and after the output filtering, it charges the electric Automotive battery. Charging can be done in four modes: fixed quantity, fixed time, fixed amount, and automatic (until fully charged).

▲ Electric vehicle charging structure diagram

To sum up, the working principle of the Charging station can be summarized as the combination of power supply, converter and output device to change the voltage from low to high, convert the high voltage into a state that can provide power supply, and finally charge the electric vehicle.

Composition of Charging station

The main structure of Charging station includes pile body, charging module, display screen, connecting cable, accounting management module, safety protection device, etc. The structural design and quality of these parts directly affect the service life and safety of Charging station.

1) Pile body

The pile structure of Charging station is usually made of steel, aluminum alloy and other materials, with strong durability and stability.

2) Charging module

Charging module is the core part of Charging station, including charger, controller, power supply and other components. The charger is the main component of the Charging station, which is responsible for converting the electric energy into the electric energy required by the electric vehicle. The controller is responsible for controlling the working state of the charger and various parameters during the charging process, ensuring the safety and stability of the charging process. The power supply provides electrical energy for the charging module.

3) Display screen

The display screen of the Charging station is usually used to display the status, charging progress, charging cost and other information of the Charging station. The types and sizes of display screens are different. Some Charging station are also equipped with touch screens, which are convenient for users to use, realize human-computer interaction, and meet the personalized needs of different types of users.

4) Accounting management module

The accounting management module calculates the current consumption amount based on the current real-time electricity price and consumed electricity data, collects fees, and prints bills. Completing accounting management tasks requires the cooperation of controllers and embedded printers. The Charging station adopts the trapezoidal electricity price policy. The controller calculates the consumption amount and completes the charging. 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) Connecting cables

The connecting cable is the bridge between the Charging station and the electric vehicle, which is responsible for transmitting electric energy and data. The quality and length of the connecting cable directly affect the charging efficiency and safety. Some high-end Charging station are also equipped with an automatic Fishing reel, which is convenient for users.

6) Safety protection device

The safety protection devices of the Charging station include leakage protection, overcurrent protection, overvoltage protection, etc. These devices can effectively protect the safety of the Charging station and electric vehicles.

▲ Schematic diagram of AC contactor circuit

The design and manufacturing quality of the above six major parts directly affect the service life and safety of the Charging station. Therefore, attention should be paid to these aspects when purchasing Charging station.

Charging mode of Charging station

There are three main charging modes for the Charging station, namely fast charging, slow charging and wireless charging.

1) Slow charging

Slow charging is a commonly used charging method. For the Charging station of new energy electric vehicles, it is connected to the on-board charger. It mainly converts low power AC power into DC power, 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 by DC. In addition, the slow charging interface of new energy electric vehicle Charging station is generally 5 holes.

2) Fast charging

Fast charging is a popular way of charging, as it saves time. Fast charging is to connect the AC-DC converter to the new energy electric vehicle Charging station, and the charging gun will output high-power DC. Moreover, the charging current of the interface is generally large, and the battery cell is much thicker compared to slow charging, and the number of holes in the battery cell is also much larger. The fast charging interface of new energy electric vehicle Charging station is generally 7 holes.

3) Wireless charging

From an official definition, wireless charging of new energy vehicles refers to a high-power charging method that replenishes the energy of high-voltage power batteries. Similar to the wireless charging of smartphones, placing the phone on the wireless charging panel allows for battery charging without connecting a charging cable. At present, the technical methods for wireless charging of electric vehicles are mainly divided into four types: “electromagnetic induction, magnetic resonance, electric field coupling, and radio waves”. Meanwhile, due to the low transmission power of electric field coupling and radio waves, electromagnetic induction and magnetic field resonance are currently mainly used.

In addition to the three charging methods mentioned above, electric vehicles can also achieve energy replenishment through battery swapping.