Decentralized DC Power Exchange System for DC Microgrids

A decentralized DC power exchange method is proposed to enable direct bidirectional power transfer among geographically distributed DC microgrids. Each microgrid is connected to a shared power exchange grid via a bidirectional DC/DC converter, al-lowing flexible participation regardless of location. The architecture supports dynamic scalability, permitting microgrids to join or leave the exchange network without dis-rupting overall operation. To evaluate the feasibility of the proposed method, a 2-to-2 power exchange experiment was conducted using lithium-ion batteries configured to emulate microgrid baselines. The results demonstrated that arbitrary power ratios can be achieved through appropriate adjustment of converter parameters, and that trans-mission loss and efficiency varies depending on the power distribution ratio. In addi-tion, the operational stability of the system was experimentally verified under sudden fluctuations in baseline voltage, such as those caused by abrupt changes in generation or load. Stable power exchange was maintained even under disturbances of several percent. These findings confirm the practicality and robustness of the converter-based archi-tecture and highlight its applicability to scalable, distributed DC microgrid intercon-nection.