Based on the synchronous grid connection of pumped storage units

Conventional pumped storage units require fast and accurate grid connection to reduce the impact on the units during grid connection. This article first analyzes the principle and allowable conditions of quasi synchronous grid connection of the unit, and theoretically analyzes the impact of voltage difference, frequency difference, and phase angle difference on the unit's impulse current during the grid connection process. Secondly, this article uses Simulink software to build a single machine grid connected simulation model with quasi synchronous modules. Finally, this article conducted simulation analysis on the changes in impulse current during grid connection of the unit with three different conditions: voltage difference, frequency difference, and phase angle difference, providing guidance for the synchronous grid connection of the pumped storage unit.