Tuning of PI Controllers for Middle Route South-North Water Transfer Project

The development of a new method to tune robust distant downstream proportional integral controller for a canal pool is a challenging and critical issue. The paper proposed a new method to tune the PI controller, using the pool volume as control target. Firstly, the gain and phase margins of the control system of the pool are given, and the PI controller tuning is implemented based on channels ID (Integrate Delay) model for the Middle Route South-North Water Transfer Project. Then, the gain and phase margin of pool can be calculated again through the precise integration of frequency domain transfer function based on the Saint-Venant equations. Calculation result shows that the simulated gain and phase margins are difference a lot with the designed gain and phase margins, and the PI controller tuning based on ID model is lack of precision. By analyzing the Bode diagram of a pool, two pool configurations are going to be classified: one is short flat pool and one long slopping pool. PI controller is enough for the long slopping pool, but the PIF controller should be applied on the short flat pool, for exhibiting high resonant peaks in the Bode diagram due to the effect of water waves traveling back and forth through it. At last, the influence of the several controller parameters on the gain and phase margins are studied, and this work can be used to adjust the controller parameters for designed gain and phase margins.