Risk-based decisions
Evacuation of a residential area
Self-help capacity during floods
Outflow regulation during high water levels
Information & Self Sufficiency
Decision making and coordination
CONTROLLING HYDRAULIC STRUCTURES TO OPTIMISE FLOOD CONTROL
RISK-BASED DECISIONS
The most common technique for supervisory control of hydraulic structures in water resources is the definition of reactive operating rules. Examples include minimum releases for reservoirs depending on the reservoir level and environmental objectives,
the operation of flood detention basins based on water level at reference locations, or the definition of set points for upstream water levels of river weirs. These operating rules typically come along with secondary controllers for controlling the desired variable at site,
i.e. a PID-controller for maintaining an upstream water level at a weir.
Whereas this concept works well for smaller water systems, its application gets significantly more complex for larger systems, in particular if these systems have a high degree of interconnectivity such as the Dutch Rhine-Meuse delta. In these cases, the
operating rules and the water system may show undesired feedback effects leading to suboptimal control of the total system. Looking for examples related to the control of cascaded hydropower plants, many authors report drawbacks of classical feed forward /
feedback control methods due to amplification of inflow disturbances.
We present a general nonlinear MPC scheme for the control of hydraulic structures
in complex water resources systems.
MPC is a control concept, which has become an industrial standard in process control over the last two or three decades. It makes use of a process model for predicting future trajectories of the controlled variables over a finite horizon, in order to determine the optimal set of manipulated variables by an optimization algorithm. An integral part of the concept is the explicit consideration of constraints on inputs, states and outputs. Furthermore, the tuning of the control parameters is relatively straightforward even in the presence of contradictory control objectives.
We present the application of the NMPC on the control of a generic reservoir system and on several hydraulic structures of two flood detention basins at the bifurcation points of the River Rhine in The Netherlands.
Downloads:
- Nonlinear model predictive control of water resources systems in operational flood forecasting (PDF, 0.2 MB)