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On-line estimation of time-varying delays in district heating systems

Abstract

For simulation and control of a district heating system it is of interest to build a mathematical model of the distribution network. This paper deals with stochastic models of the time-variation of temperatures in distribution networks. Due to variations of the water flow in the distribution network it is not possible to apply traditional modeling techniques assuming a constant time-delay between temperature signals. Two methods for tracking both the delay and the dynamics of an input-output system are presented. The methods are based on recursive estimation of the parameters of ARMAX models. In the first method simultaneous recursive estimation of the parameters of a number of ARMAX models with different delays is performed. The second method tracks the states - amongst these the delay - of a state space model formulation. The performance of the estimation methods is illustrated on data from a district heating system. It appears that the performance of the estimation methods depends strongly on the dynamical characteristics of the variations of the delay. The best results are achieved for slowly varying delays. As both methods are based on adaptive schemes they are well suited for on-line applications. Furthermore, the generality of the methods make them applicable  More>>
Publication Date:
May 01, 1991
Product Type:
Conference
Report Number:
DTH-IMSOR-RR-1991-2; CONF-9106417-
Reference Number:
SCA: 320603; PA: DK-92:001877; SN: 93000918281
Resource Relation:
Conference: ESM`91: European simulation multiconference,Copenhagen (Denmark),17-19 Jun 1991; Other Information: PBD: May 1991
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; HEAT DISTRIBUTION SYSTEMS; TEMPERATURE CONTROL; SIMULATION; COMPUTERIZED CONTROL SYSTEMS; DISTRICT HEATING; MATHEMATICAL MODELS; TIME DELAY; PROBABILISTIC ESTIMATION; 320603; PUBLIC UTILITIES
OSTI ID:
10113399
Research Organizations:
Technical Univ. of Denmark, Lyngby (Denmark). Inst. of Mathematical and Operations Research
Country of Origin:
Denmark
Language:
English
Other Identifying Numbers:
Other: ON: DE93752970; TRN: DK9201877
Availability:
OSTI; NTIS
Submitting Site:
DK
Size:
21 p.
Announcement Date:
Jun 30, 2005

Citation Formats

Soegaard, H T, and Madsen, H. On-line estimation of time-varying delays in district heating systems. Denmark: N. p., 1991. Web.
Soegaard, H T, & Madsen, H. On-line estimation of time-varying delays in district heating systems. Denmark.
Soegaard, H T, and Madsen, H. 1991. "On-line estimation of time-varying delays in district heating systems." Denmark.
@misc{etde_10113399,
title = {On-line estimation of time-varying delays in district heating systems}
author = {Soegaard, H T, and Madsen, H}
abstractNote = {For simulation and control of a district heating system it is of interest to build a mathematical model of the distribution network. This paper deals with stochastic models of the time-variation of temperatures in distribution networks. Due to variations of the water flow in the distribution network it is not possible to apply traditional modeling techniques assuming a constant time-delay between temperature signals. Two methods for tracking both the delay and the dynamics of an input-output system are presented. The methods are based on recursive estimation of the parameters of ARMAX models. In the first method simultaneous recursive estimation of the parameters of a number of ARMAX models with different delays is performed. The second method tracks the states - amongst these the delay - of a state space model formulation. The performance of the estimation methods is illustrated on data from a district heating system. It appears that the performance of the estimation methods depends strongly on the dynamical characteristics of the variations of the delay. The best results are achieved for slowly varying delays. As both methods are based on adaptive schemes they are well suited for on-line applications. Furthermore, the generality of the methods make them applicable to a wide class dynamic systems which contains time-varying delays. (au).}
place = {Denmark}
year = {1991}
month = {May}
}