This study proposes a systematic approach to model and control a triple-active-bridge (TAB) converter for electric vehicle on-board charger applications. An innovative generalised-harmonic-approximation (GHA) modelling method is proposed to accurately predict the instantaneous current and voltage waveforms. Based on the GHA modelling, a control strategy for a TAB converter is proposed, which enables the power flow from grid to two batteries with high conversion efficiency while achieving zero-voltage switching operation. Compared to the conventional phase-shift modulation, the proposed control method achieves an extended operating range of simultaneous charging operation mode, especially under the unbalanced load conditions. As a proof-of-concept, a 600 W prototype is built and tested. The experimental results are presented including waveforms of different operation modes and efficiency measurements. The peak efficiency of the TAB converter under the G2B mode is measured as 97.6%. The experimental waveforms exhibit good agreement with the waveforms obtained through GHA modelling.

中文翻译：

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三有源桥变换器的建模与控制

这项研究提出了一种系统化的方法来建模和控制电动汽车车载充电器应用中的三有源桥（TAB）转换器。提出了一种创新的广义谐波近似（GHA）建模方法，可以准确地预测瞬时电流和电压波形。基于GHA建模，提出了一种TAB转换器的控制策略，该策略可实现从电网到两节电池的电能高效转换，同时实现零电压开关操作。与常规相移调制相比，所提出的控制方法实现了同时充电操作模式的扩展操作范围，尤其是在不平衡负载条件下。作为概念验证，构建并测试了600 W原型。给出了实验结果，包括不同操作模式和效率测量的波形。在G2B模式下，TAB转换器的峰值效率为97.6％。实验波形与通过GHA建模获得的波形具有很好的一致性。