What is the principle of wireless charging in cars?

You can first look at the scenarios of wired charging and wireless charging of electric vehicles.

That’s right. To put it simply, the disadvantages of wired charging are: the number of cars that can be charged at the same time is limited, outdoor wired charging piles are vulnerable to damage, and they occupy a relatively large area.

There are three types: 1) electromagnetic induction 2) radio wave 3) magnetic field resonance

The first is electromagnetic induction.

Electromagnetic induction - the alternating current of a certain frequency in the primary coil generates a certain current in the secondary coil through electromagnetic induction, thereby transferring energy from the transmitting end to the receiving end.

The second is the radio wave type.

Basic principle - similar to the crystal radio used in the early days, it mainly consists of a microwave transmitting device and a microwave receiving device. The receiving circuit can capture the radio wave energy bounced back from the wall and maintain a stable DC voltage while adjusting with the load.

Finally, there is magnetic field resonance.

Principle: It consists of an energy sending device and an energy receiving device. When the two devices are adjusted to the same frequency, or resonate at a specific frequency, they can exchange each other's energy.

The actual structure and principle of the wireless charging system for electric vehicles.

The system consists of a primary circuit located outside the car and a secondary circuit, rectifier and drive system located inside the car. Usually when charging, the primary coil with a flat iron core, the coupler, is manually inserted into a gap in the secondary iron core, so that energy can be transferred from the primary circuit placed at the bottom to the battery.

Nissan Cube Electric Vehicle: It uses electromagnetic induction to provide power between the power supply coil and the power receiving coil. One power receiving coil device is installed on the chassis of the car, and the other power supply coil device is installed on the ground. When the electric car drives onto the power supply coil device, the power receiving coil can receive the current from the power supply coil, thereby charging the battery. At present, the rated output power of this device is 10kw, and ordinary electric vehicles can be fully charged within 7-8 hours.

Japan's wireless charging hybrid bus: electromagnetic induction type, the power supply coil is buried in the concrete of the charging platform. After the car is driven onto the charging platform, when the onboard coil is aligned with the power supply coil (overlapping), an indicator light on the dashboard of the car will light up, and the driver will press the charging button to start charging. What does wireless charging technology for cars mean?

Automobile wireless charging technology means that electric vehicles can be charged without relying on charging cables. It mainly realizes non-contact power transmission through electromagnetic induction, electromagnetic resonance, radio frequency and other methods.

Electric vehicle charging can be achieved without relying on charging cables, and non-contact power transmission can be achieved through electromagnetic induction, electromagnetic resonance, radio frequency, etc. There is no exposed connector for wireless charging of cars, which can adapt to various harsh environments and weather, and avoid safety hazards such as leakage and power outages. It is easy to use, and the vehicle can be charged by simply parking at a fixed position without supervision. And the power transformer is hidden underground, saving space. The power is low, and it can only be charged slowly, and the transmission efficiency is lower than that of wired charging. Inductive charging has strict requirements on the location of the vehicle. Compared with charging piles, the cost is higher, and the charging standards of different brands are also different. There are two ways to charge cars: electromagnetic induction and magnetic resonance. Wireless charging is currently widely used. The principle is to use the principle of electromagnetic induction. There is a coil at the transmitting end and a coil at the receiving end. Alternating current of a certain frequency passes through the primary coil. Due to electromagnetic induction, a certain current is generated in the secondary coil, so that energy is transferred from the transmitting end to the receiving end. Its advantages are high conversion efficiency, short charging distance, and only one-to-one charging is required. Magnetic field wireless charging consists of an energy transmitter and an energy receiver. When the two devices are tuned to the same frequency, or resonate at a specific frequency, they can exchange each other's energy. The principle is the same as that of sound resonance. Coils with the same vibration frequency arranged in a magnetic field can supply power from one to another. The transmission distance of resonance is farther than that of ordinary induction. And multiple vehicles can be charged at the same time without precise alignment. However, the energy loss in transmission is large. What is the principle of wireless charging for cars and what is the significance of wireless charging technology for cars? Many people still don't know. Let's take a look now! 1. Electric energy is transmitted by non-contact methods such as electromagnetic response, electromagnetic resonance, and frequency emission. 2. In this case, charging is carried out without leaking the connector. 3. Avoid safety hazards such as leakage and running during charging. It is very convenient to use and can also avoid cluttered circuits. 4. Wireless charging of motor vehicles is a function only available in some mid-to-high-end models. 5. After use, it is convenient for the driver to charge some parts of the motor vehicle. 6. Wireless charging can charge related items such as mobile phones and computers. 7. Motor vehicles can be charged wirelessly without the need for an external connector, avoiding safety hazards such as leakage or running.

Wireless charging for electric vehicles may be a game changer for the automotive industry. It is a promising technology that lays wireless charging on the road and is expected to completely solve the winter endurance and charging problems of electric vehicles. Wireless charging is now widely used in mobile phones, and wireless charging of mobile phones on the car's central control has become a common configuration, but few electric vehicles use wireless charging. What is the principle of wireless charging technology? Which brands are developing it? Which domestic brands have already gone into mass production? Let's take a detailed look below.

What is wireless charging?

Wireless charging is already widely used in devices such as mobile phones and electric toothbrushes. Instead of using wires to transmit electricity, wireless charging relies on induction charging, where power is transferred from one coil in the charger to another coil in the car. Wireless charging is based on the principle of electromagnetic induction, which transfers power through the air as a magnetic field. This means that power can be sent from one device to another without physical contact, but only if the charger and car are in close proximity. Once both the transmitting and receiving coils are aligned, charging can begin.

Wireless systems do not require wires, but rather a charging pad, where the electric car stops to charge the battery. Optimized power electronics and coil design minimize energy losses, and wireless charging is currently 90-93% efficient, and as the technology is optimized, it will reach the efficiency of traditional wire charging (94-96%) in the future.

This contactless charging can improve the safety and convenience of charging. If autonomous driving is fully implemented in the future, wireless charging is indispensable and is also the core step for fully autonomous driving of electric vehicles. Another advantage of wireless charging is that it is more convenient to arrange, and roadside parking spaces can be set up at will without taking up space. In the future, when there are a large number of electric vehicles, charging convenience will be much higher.

Which brands are developing wireless charging for cars?

Siemens, a global technology company, has been researching wireless charging for a decade. Siemens expects that the global electric vehicle wireless charging market will reach about 2 billion euros by 2028. Siemens and Mahle, a German automotive parts supplier, have signed an agreement to work on automotive wireless charging facilities. It plans to launch a new platform from 2025 to meet the needs of wireless charging automotive infrastructure.

Geely-owned Volvo is also a pioneer in wireless charging and has been testing the technology in a real urban environment in Gothenburg. The XC40 electric version is used as a test car, using 540-degree transparent chassis technology to align the car with the charging plate when parking. Volvo's measured charging speed is 4 times faster than an 11kW AC charger and is close to a 50kW DC fast charging speed on a wire.

WiTricity, a global developer of wireless charging technology, has also extended its reach into the automotive field. Hyundai Motor has cooperated with WiTricity, and its current mass-produced GV60 pure electric SUV is already equipped with wireless charging, which is a standard feature when it leaves the factory.

The E-HS9, the first high-end pure electric SUV of a domestic independent brand, is also equipped with wireless charging, which is a car wireless charging jointly developed by Hongqi and Zhejiang Wanan Technology. As long as it is used in a standard wireless charging parking space, it will automatically charge when parked. The 11kW charging power can fully charge the vehicle in 8.4 hours, which is close to the charging speed of a home charging station.