Start-up process optimization of pumped-storage unit with Tilt–Integral–Derivative controller

Focused on the hydraulic–mechanical coupled transient behaviors of the pumped-storage unit (PSU), this paper discusses the theoretical implementation and the parameter optimization of tilt–integral–derivative (TID) controller in turbine start-up processes. A novel learning backtracking search algorithm (LBSA) is adapted to optimize the control parameters, and a comprehensive index combining the relative deviation of the rotational speed and the relative deviation of the volute’s water pressure is designed as the objective function. A nonlinear mathematical model which can reflect hydraulic and mechanical dynamic characteristics of the pumped-storage governing system (PSGS) is established for the simulation of the transient period. Simulation experiments of two typical operating conditions are carried out under no-load condition. The simulation results show that the TID controller attaches significance to suppressing the amplitude of water hammer pressure and damping the hydraulic fluctuations. It will also restrain the trend of state trajectories oscillating back and forth in the unstable “S” shaped regions.