Hybrid energy storage system

The invention relates to the technical field of energy storage, in particular to a hybrid energy storage system. A hybrid energy storage system of a superconducting energy storage device and a lead-acid energy storage battery pack is adopted to stabilize power fluctuation in an example, the lead-acid energy storage battery pack is connected to a direct-current bus in parallel through a DC/DC module, and the superconducting energy storage device is connected to the direct-current bus in parallel through a V/I module; the substation is connected to a power grid through a converter, a direct-current bus, a transformer and a low-pass filter. The invention discusses the selection of the time constant of the low-pass filter for power distribution, and provides a method for determining the time constant of the low-pass filter. Simulation results show that after the hybrid energy storage system is adopted, the system can well stabilize power fluctuation, so that a transformer substation outputs stable power to a powe