Fast Voltage Regulation and Grid Connection Method for Generator-Motor of Vertical Gravity Energy Storage Systems

The basic requirement of the grid connection of the gravity energy storage generator-motor is that the voltage phase sequence, frequency, amplitude and phase of the machine end and the network end need to be consistent. However, when the actual gravity energy storage system is connected to the grid, due to the different start-up and grid-connected methods, as well as the deviation of the control system, it is difficult to make the voltage indicators of the terminal and the network terminal completely consistent, which in turn generates transient impulse current. In view of the above problems, this paper establishes a grid-connected model of vertical gravity energy storage system, and proposes a grid-connected method of gravity energy storage generator-motor based on fast voltage regulation control. Through simulation verification, this method can make the three-phase current of motor stator smoothly transition to steady state after grid-connected, and achieve the purpose of suppressing grid-connected impulse current. The correctness and practicability of the proposed method are fully verified.