Recent interest in electric vehicles with onboard solar generation presents a new opportunity for using solar electric vehicles (SEVs) for distributed generation when the traction battery is fully charged. This concept presents a new power electronic challenge: the onboard charger should have high efficiency in the grid-to-vehicle (G2V) direction for normal charging power levels (i.e., 6.6 kW) and also high efficiency in the vehicle-to-grid (V2G) direction for much lower solar power levels (i.e., < 800 W). However, typical onboard charger topologies have low efficiency at light loads. This article proposes a novel bidirectional LLC+C converter to address this challenge. It operates as a full-bridge LLC converter in the G2V direction and a half-bridge LLCC converter with a smaller transformer in the V2G direction. Simulation results show a maximum efficiency gain of 5.1% in the V2G direction compared to the standard full-bridge LLC converter. To experimentally validate the topology and operation, a 6.6-kW prototype with 450–700-V input is designed, built, and tested. The experimental results show that the proposed converter achieves high efficiency in the V2G direction at 700 W (95.7%).

中文翻译：

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用于太阳能充电电动汽车的具有并联变压器的高效双向 LLC+C 谐振转换器


最近对带有车载太阳能发电的电动汽车的兴趣为在牵引电池充满电时使用太阳能电动汽车（SEV）进行分布式发电提供了新的机会。这一概念提出了新的电力电子挑战：车载充电机应在正常充电功率水平（即6.6 kW）下在电网到车辆（G2V）方向上具有高效率，并且在车辆到电网（G2V）方向上也应具有高效率。 V2G）方向，以获得更低的太阳能功率水平（即< 800 W）。然而，典型的车载充电器拓扑在轻负载时效率较低。本文提出了一种新型双向 LLC+C 转换器来应对这一挑战。它在 G2V 方向上用作全桥 LLC 转换器，在 V2G 方向上用作带有较小变压器的半桥 LLCC 转换器。仿真结果显示，与标准全桥 LLC 转换器相比，V2G 方向的最大效率增益为 5.1%。为了通过实验验证拓扑和操作，设计、构建并测试了具有 450-700V 输入的 6.6kW 原型。实验结果表明，所提出的转换器在 V2G 方向上实现了 700 W (95.7%) 的高效率。