DC-DC Converter Application for Connecting Two Micro DC Grids and Operating Method

Abstract

The invention relates to an isolated bidirectional DC-DC converter and an operating method for connecting and exchanging energy between two DC microgrids (MGs). The converter comprises a pulse transformer connected to main switching switches and specifically incorporates an energy recovery circuit on each side of the grid. This recovery circuit consists of a recovery switch in series with a recovery capacitor, configured to recover energy from the leakage inductance of the transformer windings. The controller receives current and voltage signals from both grids to determine the power state, thereby controlling the sequential pulse supply to the main and recovery switches in forward, reverse, or independent energy transfer modes. The invention optimizes bidirectional energy transfer efficiency by recovering excess energy, while simultaneously reducing voltage stress on semiconductor components and maintaining voltage stability for the microgrid system.

Images