磁耦合谐振式无线电能发射系统的设计与实现

磁耦合谐振式无线电能传输技术是现代电工技术领域研究与开发的热点,是目前最有可能为便携式电器及植入式医疗器械、智能可穿戴技术,实时无线供电的一种最佳的电能柔性接入与传输手段。为了摆脱传统电源线的束缚,解决供电方式在空间与距离上的限制。以强耦合理论为基础制作了一套高度为20cm、直径为60cm、匝数为5.25的空心铜线发射及接收线圈,据此理论谐振频率为7.65MHz,与实际测量值8MHz偏差4.5%。通过8MHz方波信号控制E类功率放大器栅极,在功放的漏极考虑了非线性电容和线性并联电容的非理想因素影响,并对外接电容值进行了优化以获得E类功放的最大效率。对功放的输出端进行阻抗匹配,达到最大功率发射。最后实现了发射线圈几何尺寸直径为60cm的最大传输距离为6m。由实验分析可知,本系统在传输距离上有很大的提高。

Design and implementation on the emission system of magnetic coupled resonant wireless power transmission

Wireless power transmission (WPT) based on the magnetically-coupled resonant is a hot topic in the research and development in modern electrical technology. It is the most likely to be a technology to provide solutions for wireless power supply of electrical equipment, such as household appliances, various consumer electronic products, smart wearable devices and embedded medical devices. The WPT is a flexible access and transmission for real-time power supply. In order to get rid of the shackles of the traditional power cord, the limitation of the space and distance of the power supply mode is solved. Using coupled-mode theory, the two identical helical coils are built with the height of 20 cm, the diameter of 60 cm and the number of turns of 5.25. Both coils are made of hollow copper wire. The expected resonant frequency given is 7.65 MHz, which is about 4.5% off from the measured resonance at 8 MHz. Control the class E power amplifier(PA) gate with an 8 MHz square wave signal, The effects of the nonlinear and linear shut capacitance have been considered in the drain of PA, it is important to predict the performance when an external capacitor is necessary to add for the optimal Class-E mode. Impedance matching is designed to maximum the power transfer from the drain of PA to the transmission coil. The system achieves the maximum transmission distance of 6 meters on the theoretical basis of the transmitting coil of diameter of 60 cm. According to experimental analysis, the system has a great improvement in transmission distance.