Inertial characteristics of gravity energy storage systems

Gravity energy storage is a technology that utilizes gravitational potential energy for storing and releasing energy, which can provide adequate inertial support for power systems and solve the problem of the volatility and intermittency of renewable energy generation. The inertial features of gravity energy storage technology are examined in this work, including the components of inertial support, directionality, volume, and adjustability. This paper establishes a mathematical model of the gravity energy storage system. It derives its expression of inertia during grid-connected operation, revealing that the inertial support consists of two components: the rotational kinetic energy of the motor rotor and the operational kinetic energy of the mass. This paper analyzes the inertia support characteristics of the mass and finds that it has the characteristics of single-directional, auxiliary frequency modulation and is not affected by transmission equipment, proving that the inertia support of the mass is equal to the amount of its running kinetic energy change. Finally, this paper verifies the inertia characteristics of gravity energy storage by establishing a microgrid simulation model based on MATLAB/Simulink.