Quantized pressure control in large-scale nonlinear hydraulic networks

It was shown previously that semi-global practical pressure regulation at designated points of a large-scale nonlinear hydraulic network is guaranteed by distributed proportional controllers. For a correct implementation of the control laws, each controller, which is located at these designated points and which computes the control law based on local information only (measured pressure drop), is required to transmit the control values to neighbor pumps, i.e. auxiliary pumps which are found along the same fundamental circuit. In this paper we show that quantized controllers can serve well to this purpose. Besides a theoretical analysis of the closed-loop system, we provide experimental results obtained in a laboratory district heating system. This approach is fully compatible with plug-and-play control strategies.