The invention provides a gravity and
flywheel combined comprehensive physical
energy storage system and an
energy storage method. Wherein the gravity
energy storage module comprises a gravity energy storage motor, an
elevator, a steel cable, a lifting appliance, a weight block, a vertical shaft and the like; the
flywheel energy storage module comprises an energy storage
flywheel rotor, a flywheel main shaft, an energy storage flywheel motor, a bearing, a
vacuum chamber, a protective shell and the like; the
frequency modulation flywheel module has the same structure as the
flywheel energy storage module; the comprehensive physical energy storage
system further comprises a
machine-side converter, a grid-side converter, a direct-current
bus, an
energy management system, a controller and the like. According to the invention, long-time stable
discharge to the
power grid is realized through cooperation of the gravity and the
flywheel energy storage system, and the influence of frequent start and stop and intermittency of the gravity energy storage unit on the
power grid and the system is avoided. While energy storage is realized, a special
frequency modulation flywheel is equipped to complete the
frequency modulation function of a
power grid connected with the energy storage system, and the stability of the frequency of the power grid is also realized while the stability of the output power is ensured, so that the
operation safety and reliability of the power grid are improved.