HYBRID SYSTEM WITH MULTIPLE ENERGY STORAGE DEVICES

A hybrid energy system (11, 102) for providing power to a load (118) and for providing a fast variation of DC link voltage to improve system efficiency is disclosed. The system includes a load (118), a direct current (DC) link (16, 114) electrically coupled to the load (118), an energy storage system (15, 106) having a first energy storage device (14, 110) and a second energy storage device (20, 112) arranged in series, and a bi-directional DC-DC converter (12, 108) electrically coupled to the DC link (16, 114) and to the energy storage system (15, 106), the bi-directional DC-DC converter (12, 108) being connected to a node (21, 124) located between the first energy storage device (14, 110) and the second energy storage device (20, 112) and to a node (22) connecting the second energy storage device (20, 112) to the DC link (16, 114).