一种带电磁屏蔽的绕组混合绕制非接触变压器

非接触变压器的耦合系数是影响感应式无线电能传输系统效率的关键因素。为提高非接触变压器的耦合系数,同时尽量减小其体积重量,提出由平面绕组和垂直绕组构成的绕组混合绕制的非接触变压器。然而垂直绕组的引入使得变压器外侧增加了一个新的漏磁路径。为抑制该漏磁,提高耦合系数,选择金属铝进行电磁屏蔽。通过磁路分析给出了屏蔽层的最佳长度公式。最后,为验证变压器有效性及优化方法正确性,制作了一个新型变压器并进行对比实验。与现有变压器相比,在10 mm气隙下,变压器耦合系数从0.523提高到0.583,尺寸从90 mm减小到73 mm。

Loosely Coupled Transformer with Mixed Winding and Electromagnetic Shielding

The loosely coupled transformer is the key component of an inductive power transmission(IPT)system. In order to reduce the size of the loosely coupled transformer, mixed winding arrangement containing planar winding and vertical winding is proposed. However, since the vertical winding is adopted, the proposed transformer has a large part of leakage flux at the back of the core, resulting in low coupling coefficient k. An aluminium sheet is attached to the back area as electromagnetic shielding to avoid this problem and improve the coupling coefficient. Then, the length of the aluminium sheet is optimised. A loosely coupled transformer with mixed winding and shielding is fabricated in the lab. The optimization of the length of the shielding is found by experimental measurement to be very accurate. A loosely coupled transformer with k of 0. 583 and length of 73 mm is achieved. Compared with the previous transformer having k of 0. 523 and length of 90 mm, the proposed transformer is smaller size and higher k. This work is supported by National Natural Science Foundation of China(No. 51377081).