| Abstract |
A hybrid energy storage system (HESS) to integrate different energy storage (ES) devices is presented. In this way, ES-devices with complementary physical properties can be used in medium-voltage direct current (MVDC) grids. The aggregation and integration of different ES-technologies is indispensable for operating MVDC distribution grids based on renewable energy sources (RES). State-of-the-art ES- devices are interfaced to alternating current (AC) grids by multiple power electronic converter stages and bulky transformers. Considering the independent operation of MVDC microgrids, an intermediate interface, that aggregates low voltage (LV) ES-devices, is crucial. The proposed HESS topology offers scalability and expendability for the direct integration of ES-devices and avoids lossy AC/DC conversion stages. Besides, great flexibility concerning the installation location inside the MVDC-grid is provided. |
