The adjustment of DC bus voltage is one of the most critical challenges in DC microgrids. Any changes in power generation or load leads to voltage fluctuation. Recently, the DC electric spring (DCES) has been suggested for bus voltage adjustment and maintaining the DC network stability. An electric spring is a power electronic converter that adjusts the voltage of critical loads (sensitive loads) by utilizing the variations in the power of non-critical loads (insensitive loads). In this paper, a new structure of DCES, based on a fully isolated three-port converter (TPC), is presented. The proposed structure not only solves the issues associated with conventional structures, but it also provides isolation between critical and non-critical loads, as well as the battery energy storage system. Furthermore, the separate control of each port converter ensures that DCES has the required dynamic performance to keep a stable critical load voltage. Utilizing the suggested DCES structure produces an adequate voltage range for non-critical loads, reducing battery sizing and minimizing converter losses. The performance and feasibility of the three-port DC electric spring (TP-DCES) and its control method are acknowledged by the simulations carried out by the MATLAB/SIMULINK software for various scenarios.

直流母线电压的调节是直流微电网最关键的挑战之一。发电或负载的任何变化都会导致电压波动。最近，有人建议使用直流电弹簧（DCES）来调节母线电压并保持直流网络的稳定性。电弹簧是一种电力电子转换器，它利用非关键负载（不敏感负载）功率的变化来调节关键负载（敏感负载）的电压。本文提出了一种基于全隔离三端口转换器（TPC）的 DCES 新结构。所提出的结构不仅解决了与传统结构相关的问题，而且还提供了关键负载和非关键负载以及电池储能系统之间的隔离。此外，每个端口转换器的单独控制确保了DCES具有保持稳定的临界负载电压所需的动态性能。利用建议的 DCES 结构为非关键负载提供足够的电压范围，从而减小电池尺寸并最大限度地减少转换器损耗。通过MATLAB/SIMULINK软件针对各种场景进行的仿真验证了三端口直流电动弹簧（TP-DCES）及其控制方法的性能和可行性。