| The freezing process during the winter of long-distance water transfer projects limits the canal capacity. Inflow warm water from the lower layer of the offline reservoir can increase the canal"s water temperature, effectively shorten the temporal and spatial range of canal icing. If the reservoir supplies water to the canal at a constant flow rate throughout the winter, limited storage capacity may lead to reservoir emptying; Moreover, the current control mode of the canal system mostly needs constant downstream water level. The inflow from the reservoir will disrupt the hydraulic stability of the canal, causing the water level at downstream control points to deviate from the target value, increasing the difficulty of automatic control of the canal system, and even causing the canal to overflow. Therefore, this study designed a water temperature controller for long-distance water transfer canal systems, which dynamically adjusts the inflow from the reservoir based on the water temperature at the control point to save water from the reservoir; A collaborative regulation mode of water temperature and level in long-distance water conveyance canal system has been proposed: based on the traditional water level feedback controller, the reservoir inflow output from the water temperature controller is introduced as the feedforward of the water level controller to assist downstream control points in maintaining stable water level. The results show that the water temperature controller can effectively control the water temperature at the control point between 0.5 ℃ and 2 ℃, preventing ice from occurring between the inflow point and the control point, and saving 20% of the reservoir water compared to the constant inflow scheme. Under the coordinated regulation of water temperature and level, the water level at the downstream control point of the canal will decrease in advance to accommodate the inflow from the reservoir. Subsequently, the water level will dynamically adjust according to the change of the inflow from the reservoir and recover to the target value within 4-5 days. The water temperature water level collaborative regulation mode proposed in this study can not only ensure the warming effect of the canal, but also save water of the reservoir and ensure the stability of canal water delivery. The collaborative regulation approach proposed in this study also has reference significance for multi-objective regulation of complex systems. |