The invention provides a
flywheel energy storage system with an electromagnetic coupler, which comprises a motor, a
flywheel rotor, the electromagnetic coupler, a frequency converter and a generator, and is characterized in that the motor is connected with the
flywheel rotor to drive the flywheel rotor to rotate, the electromagnetic coupler comprises an outer rotor and an inner rotor, and the outer rotor sleeves the inner rotor and is spaced from the inner rotor; the flywheel rotor is in transmission connection with the inner rotor, the inner rotor generates a
rotating magnetic field to drive the outer rotor to rotate, and the frequency converter is connected with the outer rotor to change the current frequency of the outer rotor so as to change the
magnetic field rotating speed matched with the current, so that the mechanical rotating speed of the outer rotor is kept constant. The generator generates power, accesses the
power grid and inputs
electric energy with stable frequency into the
power grid, the requirement of
power transmission to the
power grid is met, power electronic devices are not needed, rotational
inertia in the power grid can be improved, necessary
voltage and frequency support is provided for the power grid, and the capacity of the power grid for efficiently accepting
new energy is improved.