CUI Wei, CHEN Wen-xue, MU Xiang-peng, WANG Qi
(China Institute of Water Resources and Hydropower Research, Beijing 100038, China)

Abstract: The variable downstream depth operation method applied to parts of South-to-North Water Transfer Project canal and the canal control algorithm for the whole canal during the transient period before winter are presented in this paper. The implementation of the operation method consists of two simultaneous processes, i.e. constant downstream depth operation and variable downstream depth operation with volume compensation, which achieve flow rate balance and volume compensation balance respectively. A unified control algorithm is also presented, by which the variable downstream depth operation and the traditional constant downstream depth operation can be implemented and the canal system can be operate simultaneously in two methods, i.e. part of the canal pools operated under constant downstream depth and the others operated under variable downstream depth. The control algorithm includes three parts, i.e. feedback control algorithm, feedforward control algorithm and decoupling algorithm. The operation procedure of the Middle Route of South-to-North Water Transfer Project in the transient period before winter is simulated. During this period, the water levels in canal pools north of Anyanghe check gate are increased from the design values to the super standard values, while water levels in southern canal pools keep constant. The numerical simulation shows that the transition process can be implemented steadily in 2 days, and water fluctuations in all the canal pools are smaller than the drawdown criteria.

Key words: hydraulics; South-to-North Water Transfer Project; canals; variable downstream depth operation; constant downstream depth operation; control systems

Published in: Journal of Hydraulic Engineering, Vol. 43, No. 5, 2012