This paper proposes a tightly coupled inductive power transfer (IPT) system for the low-voltage and high-current charging of automatic guided vehicles (AGVs). There are two challenges in the system design. First, the widely varying range of the airgap introduces difficulties to design the compensation circuit. Second, the low-voltage and high-current working condition introduces difficulties to maintain the system efficiency. This paper reveals that there are a large amount of high-order harmonic currents in a tightly coupled IPT system, and we have provided an effective design method to reduce the harmonics. The integrated LCC compensation circuit is selected as a solution, showing four merits: good robustness to the airgap variation, easy controllability, convenience to optimize the efficiency, and low high-order harmonics. A prototype is implemented, and the magnetic coupler size is 220 × 200 × 10 mm. Experimental results show that it achieves 1.78 kW power transfer from a 300 V dc source to a 24 V battery with 86.1% efficiency and a 73.8 A charging current across an airgap of 15 mm. When the airgap varies between 5 and 25 mm, the system power variation is within ±36.7% and the efficiency is not significantly affected.

中文翻译：

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用于自动导引车低压大电流充电的紧耦合感应电力传输系统


本文提出了一种紧耦合感应电能传输（IPT）系统，用于自动引导车辆（AGV）的低压大电流充电。系统设计面临两个挑战。首先，气隙范围的广泛变化给补偿电路的设计带来了困难。其次，低电压大电流的工作条件给维持系统效率带来了困难。本文揭示了紧耦合IPT系统中存在大量的高次谐波电流，并提供了一种有效的降低谐波的设计方法。选用集成LCC补偿电路作为方案，具有对气隙变化鲁棒性好、易于控制、便于优化效率、低高次谐波等四大优点。实现了样机，磁耦合器尺寸为220×200×10 mm。实验结果表明，它实现了从 300 V 直流电源到 24 V 电池的 1.78 kW 功率传输，效率为 86.1%，在 15 mm 气隙上的充电电流为 73.8 A。当气隙在5mm到25mm之间变化时，系统功率变化在±36.7%以内，并且效率没有受到显着影响。