Paper Info
Title
Pressure regulation in nonlinear hydraulic networks by positive controls
Abstract
We report on our investigation of an industrial case study of a system distributed over a network, namely a large-scale hydraulic network which underlies a district heating system. The network comprises an arbitrarily large number of end-users and actuators distributed along the network. After introducing the model for such a class of networks, we show how to achieve practical pressure regulation at all the end-users by proportional controllers which use local information only. In the analysis, the presence of positivity constraints on t he actuators (centrifugal pumps) is explicitly taken into account. The findings are supported by experimental results. I. INTRODUCTION We report on our investigation of an industrial case study of a system distributed over a network, namely a large- scale hydraulic network which underlies a district heating system with an arbitrary number of end-users. The case study has been proposed by one of the industrial partners of the research project Plug & Play Process Control . One of the goals of the project is to investigate control laws which can easily reconfigure when new sensors, actuators or components are added to an existing control system. The problem we consider consists of regulating the pres- sure at the end-users to a constant value despite the unknown demands of the users themselves. The problem is addressed for a new generation of district heating systems, where pumps are distributed across the network at the end-users. The presence of multiple pumps in the network allows the diameter of the pipes to be reduced with a significant reduction of heat losses ((1)). Preliminary results on the case study have appeared in (4), where the problem was considered for a network with two end-users. The controllers we proposed were able to guarantee the desired control objective and positive flows throughout the network. In this paper, we derive the dynamic model for a general class of hydraulic networks with an arbitrary number of end- users. The controller we propose for each end-user pump is a proportional controller which uses information available at the end-user only (plus possibly information coming from the so-called boosting pumps). The kind of solution we present is in the spirit of the Plug & Play Process Controlproject since we expect that the addition of new components to the system (due, for instance, to the addition of new end-users in the district heating system) can be easily handled by the designed controllers. In the hydraulic systems we consider, centrif ugal pumps are used, and these pumps can only provide a positive
Year
Venue
Keywords
2009
Control Conference
PI control,district heating,hydraulic actuators,hydraulic systems,pressure control,actuators,district heating system,large-scale hydraulic network,nonlinear hydraulic networks,positive controls,pressure regulation,proportional controllers
Field
DocType
Citations 
Centrifugal pump,Heating system,Nonlinear system,Control theory,Control engineering,Engineering,Electro-hydraulic actuator,Arbitrarily large,Actuator
Conference
7
PageRank 
References 
Authors
2.42
5
2
Name
Order
Citations
PageRank
de persis1108779.28
Carsten Skovmose Kallesøe2206.17