Three-Dimensional Numerical Simulation of Pumped Storage Unit No-Load operation with PID control before Grid-Connected

Abstract

Abstract The “S” characteristic curve has been a persistent challenge for low-head grid connection of pump-turbine units. The stability of the no-load operation before grid connection directly determines the success of grid connection. In order to accurately simulate the characteristics of the no-load operation before grid connection, this paper applies a PID speed controller model to the full flow system 3D simulation of the pumped storage unit, using user-defined functions and dynamic grid technology. The calculation results were compared with the conventional transient calculation method and field test data, which verified the reliability of the calculation method and solved the shortcomings of the conventional transient calculation method, especially in terms of pressure pulsation. The application of this speed controller model provides a new method for studying the instability of the “S” characteristic curve in pump-turbine units.