Low-voltage battery energy storage system and dual active bridge (DAB) converter control method for DC bus connection in DC microgrid. To use power efficiently in a DC microgrid, power must be easily transferred in both directions. DAB converters can easily transfer power in both directions using only the phase shift of the gate at 50% fixed duty on the primary and secondary sides. In the transient state, however, an overcurrent occurs to charge the output capacitor. A soft start algorithm is used to overcome this overcurrent problem. In the conventional method, the control complexity and response characteristics are slow because the duty control is included and the algorithm is performed in several stages. In this study, a gate drive circuit is constructed using a pulse transformer for 50% fixed duty control and short circuit protection. A soft start control algorithm is proposed, including a first-order phase shift scheme for the stable soft start at 50% fixed duty. The 3 kW prototype DAB converter is designed and implemented for bidirectional power conversion testing. The experimental results show that stable power transfer is achieved in the initial transient state through bidirectional output control and soft start.

中文翻译：

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用于低压电池系统和DC微电网中DC总线连接的DAB转换器的浪涌电流降低技术

直流微电网中直流母线连接的低压电池储能系统和双有源桥转换器控制方法。为了在直流微电网中高效使用电源，必须在两个方向上轻松传输电源。DAB转换器仅使用一次侧和二次侧固定占空比为50％的门的相移就可以轻松地双向传输功率。但是，在过渡状态下，会发生过电流以对输出电容器充电。软启动算法用于克服该过电流问题。在传统方法中，由于包括占空比控制并且算法分多个阶段执行，因此控制复杂度和响应特性较慢。在这项研究中，使用脉冲变压器构造了栅极驱动电路，以实现50％的固定占空比控制和短路保护。提出了一种软启动控制算法，该算法包括一阶相移方案，用于在50％固定占空比下实现稳定的软启动。3 kW原型DAB转换器的设计和实现用于双向功率转换测试。实验结果表明，通过双向输出控制和软启动，可以在初始瞬态状态下实现稳定的功率传输。