Simulation parameters.

The design of a power electronic interface for high voltage difference DC buses is a key aspect in DC microgrid applications. A multi-port non isolated interleaved high-voltage gain bidirectional converter, which facilitates bidirectional power transfer and islanded operation in a DC microgrid, is presented in this paper. The forward high-voltage transfer ratio is achieved using a voltage multiplier circuit, and the high-gain step-down power conversion is performed using a resonant power module. A novel power transfer selection algorithm is proposed to control power flow among the interfaces of the RES, ESS, and DC grid converters, which utilizes the net power difference as the basis for switching the converter. The proposed converter is simulated for a 24 V PV source, 12 V battery, and 400 V DC grid interface using MATLAB/SIMULINK. A 200 W hardware prototype is implemented. The simulation results for voltages, currents, and power flow among RES, ESS, and microgrid DC bus proved an excellent voltage regulation, efficient power conversion, and a feasible duty cycle range with high voltage gain. These observations are validated through equivalent experimental results. A comparison is made regarding achieved gain, component sizing, achievable power transfer modes, efficiency, and control complexity with existing converters for DC microgrid applications. The presented topology proved to be a better interface with multiple-mode support with high efficiency.

针对高压差直流母线的电力电子接口设计，是直流微电网（DC microgrid）应用中的核心环节。本文提出一款多端口非隔离交错高增益双向变换器，可实现直流微电网中的双向功率传输与孤岛运行（islanded operation）。该变换器通过倍压整流电路（voltage multiplier circuit）实现正向高压传输比，同时借助谐振功率模块（resonant power module）完成高增益降压功率转换。本文提出一种新型功率传输选择算法，用于控制可再生能源系统（RES）、储能系统（ESS）以及直流电网变换器接口间的功率流，该算法以净功率差值作为变换器切换的依据。本文基于MATLAB/SIMULINK平台，针对24V光伏（PV）电源、12V蓄电池以及400V直流电网接口的场景对所提变换器进行了仿真验证，并搭建了一台200W的硬件原型机。针对可再生能源系统、储能系统与微电网直流母线间的电压、电流及功率流的仿真结果表明，该变换器具备优异的电压调节性能、高效的功率转换能力，以及可实现高增益的可行占空比范围。上述结论通过对应的实验结果得到了验证。本文将所提拓扑与现有直流微电网应用中的变换器进行了对比，对比维度涵盖增益实现、元件选型、可实现的功率传输模式、效率以及控制复杂度。实验结果表明，所提拓扑作为支持多模式运行的电力电子接口，具备更优异的性能与更高的转换效率。