The vehicle charger is a charger fixed on the electric vehicle, which takes AC power as the input and direct current as the output to charge the power battery directly to realize the safe automatic charging of the electric vehicle power battery.
According to the use scenario and function, the car battery charger can be divided into: Portable electronic device charger, on board battery charger, Emergency start charger, New energy vehicle special charger.
Several common product Models and Parameters
SMCZ7 series 800W fully sealed charger
Input Voltage:AC 90~264V
Output Voltage:24V/36V/48V/60V/72V
Rated Power:40~70Hz
Best TC Charger HK-L 6.6KW ev home chargers
Input Voltage:AC90V~264V
Output Voltage:108-540VDC
Rated Power:6.6KW
OBC Charger 3.3KW On Board Charger Portable Car Battery Charger
nput Voltage:90V-265V
Output Voltage:0~36V
Rated Power3.3KW
The core working principle of the car battery charger is to convert the direct current (DC) provided by the car battery or cigarette lighter interface into the appropriate voltage and current through the electronic circuit to meet the needs of the charging equipment.
The car's battery or generator usually provides 12V direct current (24V for some heavy vehicles). The car charger obtains this power from the cigarette lighter interface or OBD interface.
The need for charging voltage varies from device to device, for example, mobile phones usually require 5V (USB interface), while some fast charging technologies may require higher voltages (such as 9V, 12V or even higher). The charger realizes voltage conversion through the built-in Buck or Boost circuit.
To protect the device and enable efficient charging, the car charger also uses a smart chip to dynamically adjust the output current and prevent problems such as overload, overheating or short circuit.
After adjustment, stable current and voltage are output to external devices through USB and Type-C ports.
Electric vehicle On-board charging Unit
The car charger is composed of an input port, a control unit, a power unit, a low-voltage auxiliary unit and an output port.
Input interface
7 pin ports, three types of connections, including high-voltage power supply connection, high-voltage neutral line, vehicle chassis, low-voltage signal charging connection confirmation and control confirmation.
The standard input interface uses power frequency single-phase input 220V voltage, but if the power needs, you can also enable two alternate pin ports (pin NC1, NC2), which can achieve 380V input.
Control unit
The sampled output current and voltage are processed to pass the real-time value to the PID control loop. (PID: a closed-loop automatic control technology, is the proportion, integral, differential controller for short)
The controller compares the difference between the measured value and the expected value, and then passes the adjustment requirements to the PWM loop (PWM pulse width modulation technology).
Pulse width is used to control the length of the on-off time of the power device in the high voltage circuit, and the output current and voltage are as close as possible to the values required by the main control system.
Low voltage auxiliary unit
The low-voltage auxiliary unit is a standard low-voltage power supply, with an output voltage of 12V or 24V, used during charging to power the electrical appliances on the electric vehicle, such as the battery management system, thermal management system, automotive instrumentation, etc.
Power unit
It generally includes three parts: input rectifier, inverter circuit and output rectifier, which converts the input power frequency alternating current into direct current suitable for the power battery system voltage.
Output port
This includes two pin ports of the positive and negative terminals of the low-voltage auxiliary power supply, two pin ports of the positive and negative terminals of the high-voltage charging circuit, the chassis floor, the communication line CANH and CANL, and the charging request signal line.
The two pin ports of the high-voltage charging loop are connected to the battery pack. After the charging request signal line is confirmed between the input port of the charger and the external power supply, the charging request signal is sent to the vehicle controller through the "charging request signal line". At the same time, or after a short delay, the low-voltage auxiliary power supply is used to power the vehicle.
As an important part of modern automotive electrical system, the working principle and application scenario of vehicle battery charger reflect the organic combination of power electronics technology and practical needs. Through efficient electric energy conversion and intelligent current regulation, it not only improves the power efficiency of the vehicle environment, but also provides safer and more convenient energy support for the driver. With the continuous advancement of the electrification and intelligent process of the automotive industry, vehicle charging technology will continue to develop and improve in the fields of fast charging protocols, wireless charging, and new energy compatibility, providing a strong technical guarantee for future intelligent travel. The research and application of vehicle battery chargers is not only a microcosm in the field of electronic engineering, but also reflects the evolution trend of modern transportation technology to a greener and smarter direction.
