基于可调增益恒流源补偿网络的磁场耦合无线电能传输LED驱动电路

对于磁场耦合无线电能传输(WPT)系统,由于松耦合变压器漏感较大,补偿技术是实现其能量高效传输的关键。在半导体(LED)照明应用中,WPT LED驱动电路应直接输出LED所需的驱动电流,还应避免无功功率环流,减小器件应力,实现功率器件软开关。针对现有补偿网络的输出电流增益依赖变压器参数,而松耦合变压器存在设计受限的缺点,本文采用二端口网络理论,提出一族恒流源补偿网络,通过调节补偿参数灵活调节输出电流增益,增加变压器设计自由度。最后采用同一电路结构和变压器,分别实现了0.5A、1A和1.5A输出的WPT LED驱动电路,实验结果验证了理论分析的正确性。此外,还对所提出的可调增益补偿网络的特性进行了详细分析。

The Magnetic Coupled Wireless Power Transfer Driver Based on Adjustable Gain Constant-Current Compensation Network

Due to the large leakage inductance of the loosely coupled transformer, compensation technology is crucial to improve the transfer efficiency in the magnetic coupled wireless power transfer (WPT) system. In the light-emitting diode (LED) lighting application, the WPT LED driver should provide not only the required LED current directly, but also zero reactive power, low device stress and soft switching. Compared with the conventional compensation network whose output current gain relies on the transformer parameters significantly, as well as the loosely coupled transformer with the constrained design,a family of novel constant-current compensation network using two-port network theory was proposed in this paper,where high freedom of current gain and transformer design were achieved by adjusting the compensation parameters. The prototypes with the same circuit topology and transformer were built to realize the output current of 0.5A, 1A, 1.5A, respectively, which agreed well with the theoretical analysis. Characteristics of these compensation networks were also analyzed in detail.