Basic knowledge of automotive wireless charging solutions
The development of automotive wireless charging solution technology has been deeply researched and applied in the field of electronics. Although not widely used, it has achieved good results in the field of consumer electronics. At present, wireless charging can be divided into three types according to principles and implementation methods. Electromagnetic induction, electromagnetic resonance, radio waves, but the same is the more typical electromagnetic induction power transmission system. It is mainly divided into sending end system and receiving end system. The transmitter includes a transmitting coil, a driver, a controller, and a current and voltage feedback circuit. The receiving end includes a receiving coil, a voltage regulating circuit, a controller and a load device.
1. Electromagnetic induction technology
At present, the common wireless charging solutions for automobiles have built-in coils in electromagnetic induction, charging base and terminal respectively. After the two are close to each other, the transmitting coil generates a certain current through the electromagnetic induction receiving coil through alternating current of a certain frequency, and the point energy is transferred from The sending end is transferred to the receiving end, and power is supplied to the car from the charging stand.
At present, this technology has been widely used in the field of wireless charging. However, this method of wireless charging technology also has obvious drawbacks. ——Short transmission distance and strict location requirements. The requirements for placement are very demanding. To improve power efficiency, the positions of the coils must be aligned without offset.
2. Electromagnetic resonance technology
The principle is that energy can be transferred through two LC resonators with the same resonant frequency. A resonator consists of a large inductive coil with small capacitors connected in parallel or in series. The same resonant frequency is a necessary condition for energy transfer. For example, with two coils as resonators, the transmitter vibrates at a frequency of 10MHz to emit an electromagnetic field to the surroundings, and the receiver must also vibrate at a frequency of 10MHz to receive the transmitted energy.
One of the characteristics of this type of system is that energy can only be exchanged with targets of the same resonant frequency, and the energy loss is very small, so that larger frequencies and longer transmission distances can be obtained.
Another advantage of the magnetic field resonance method, which differs from the electromagnetic induction method, is that it does not need to perfectly align the position between the coils, providing a more efficient power supply. Magnetic resonance charging is not limited by the location, and can be charged one-to-many. Therefore, this wireless charging solution for automobiles will become the development direction of wireless power for mobile phones, electric vehicles, and home appliances in the future.
3. Communication technology
The basic principle of radio waves is similar to that of early ore radios (radio composed of only one sword wave diode), and a specially manufactured small and efficient receiver can be used to receive radio waves transmitted in space, but due to the huge space path loss, generally only use For electronic equipment with very low power, less than 100mW, the distance of the receiving equipment should not exceed 10 meters.