Power management strategy of low voltage DC micro grid

Abstract

In order to improve the efficiency and safety of the utilization of user-invested small scale renewable distributed generation (RDG), a structure of multi level DC micro grid based on the load classification, and corresponding stabilizing strategy were proposed in this paper. The methods of load classification and multi-level grid are introduced to design the structure of DC micro grid. Three flexible operational modes of the structure and corresponding stabilizing strategy in grid mode based on the calculation of real-time status of user-level micro grids were discussed. A minimum test bench with two users was established, and a Lab VIEW-based control system consists of supervisory terminal and main controller was designed for test and illustration. The results showed that the system can track the changes of status such as varying the loads and irradiance, and keep the bus voltage of the micro grid within a pre-set range. © Springer International Publishing Switzerland 2014.