Wireless power transmission system based on random SPWM control

Abstract

The invention discloses a wireless electric energy transmission system based on random SPWM control. The system comprises a transmitting part and a receiving part; the transmitting part comprises a direct-current power supply, a high-frequency inverter, an FPGA controller and a transmitting coil; the receiving part comprises a receiving coil and a series-parallel compensation network; and on the basis of injecting SPWM modulation voltage into the system, the original fixed-frequency SPWM modulation is optimized into a random switching frequency SPWM modulation mode. Voltage input with high sine fundamental wave content is obtained, on the basis of reducing higher harmonic current in the system, current frequency spectrums of the transmitting coil and the receiving coil are broadened, transmission energy is similarly and randomly distributed in different frequency lines, and the frequency spectrum of an electromagnetic field is improved. And the harmonic amplitude originally concentrated at the switching frequency and the integral multiple of the switching frequency is reduced, so that the electromagnetic interference of the wireless power transmission system to the outside due to high frequency is reduced. The system is high in reliability and high in system expandability.

Description

technical field [0001] The invention is used in the field of wireless power transmission, and in particular relates to a wireless power transmission system based on random SPWM control. Background technique [0002] With the development of human society, people have put forward higher demands for new supply methods of electric energy. Wireless transmission is a safe and convenient power transmission method, which has the advantages of flexible and convenient use, less maintenance, adaptability to harsh environments, and easy to realize unmanned automatic power supply and mobile power supply. Magnetically coupled resonant wireless power transfer technology has broad application prospects in fields such as electric vehicles, consumer electronics, sensors, and implanted devices. Wireless power transmission technology is favored by researchers and users for its convenience and flexibility. [0003] The traditional wireless power transfer system uses a fixed-frequency square wa...

AI Technical Summary

Problems solved by technology

Taking the 85kHz wireless power transmission system as an example, the carrier frequency needs to be 850kHz, which cannot be tolerated by ordinary switching devices.

However, with the application of silicon carbide devices, it is possible for SPWM modulation to be applied to wireless power transmission systems

Although the SPWM modulation method can reduce the peak harmonics of the system, such a high switching frequency will cause electromagnetic interference problems, and the fixed frequency will make the frequency spectrum of the inverter output current discrete, and the energy will be concentrated at the switching frequency and its integer multiples place

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