25,923 research outputs found
Simulation of Water Distribution Systems
In this paper a software package offering a means of simulating
complex water distribution systems is described. It has been
developed in the course of our investigations into the applicability
of neural networks and fuzzy systems for the implementation of
decision support systems in operational control of industrial
processes with case-studies taken from the water industry.
Examples of how the simulation package have been used in a
design and testing of the algorithms for state estimation,
confidence limit analysis and fault detection are presented.
Arguments for using a suitable graphical visualization techniques
in solving problems like meter placement or leakage diagnosis are
also given and supported by a set of examples
Active actuator fault-tolerant control of a wind turbine benchmark model
This paper describes the design of an active fault-tolerant control scheme that is applied to the actuator of a
wind turbine benchmark. The methodology is based on adaptive filters obtained via the nonlinear geometric
approach, which allows to obtain interesting decoupling property with respect to uncertainty affecting the
wind turbine system. The controller accommodation scheme exploits the on-line estimate of the actuator
fault signal generated by the adaptive filters. The nonlinearity of the wind turbine model is described by the
mapping to the power conversion ratio from tip-speed ratio and blade pitch angles. This mapping represents
the aerodynamic uncertainty, and usually is not known in analytical form, but in general represented by
approximated two-dimensional maps (i.e. look-up tables). Therefore, this paper suggests a scheme to
estimate this power conversion ratio in an analytical form by means of a two-dimensional polynomial, which
is subsequently used for designing the active fault-tolerant control scheme. The wind turbine power generating
unit of a grid is considered as a benchmark to show the design procedure, including the aspects of
the nonlinear disturbance decoupling method, as well as the viability of the proposed approach. Extensive
simulations of the benchmark process are practical tools for assessing experimentally the features of the
developed actuator fault-tolerant control scheme, in the presence of modelling and measurement errors.
Comparisons with different fault-tolerant schemes serve to highlight the advantages and drawbacks of the
proposed methodology
Robust Fault Diagnosis by Optimal Input Design for Self-sensing Systems
This paper presents a methodology for model based robust fault diagnosis and
a methodology for input design to obtain optimal diagnosis of faults. The
proposed algorithm is suitable for real time implementation. Issues of
robustness are addressed for the input design and fault diagnosis
methodologies. The proposed technique allows robust fault diagnosis under
suitable conditions on the system uncertainty. The designed input and fault
diagnosis techniques are illustrated by numerical simulation.Comment: Accepted in IFAC World Congress 201
Using Effective Generator Impedance for Forced Oscillation Source Location
Locating the sources of forced low-frequency oscillations in power systems is
an important problem. A number of proposed methods demonstrate their practical
usefulness, but many of them rely on strong modeling assumptions and provide
poor performance in certain cases for reasons still not well understood. This
paper proposes a systematic method for locating the source of a forced
oscillation by considering a generator's response to fluctuations of its
terminal voltages and currents. It is shown that a generator can be represented
as an effective admittance matrix with respect to low-frequency oscillations,
and an explicit form for this matrix, for various generator models, is derived.
Furthermore, it is shown that a source generator, in addition to its effective
admittance, is characterized by the presence of an effective current source
thus giving a natural qualitative distinction between source and nonsource
generators. Detailed descriptions are given of a source detection procedure
based on this developed representation, and the method's effectiveness is
confirmed by simulations on the recommended testbeds (eg. WECC 179-bus system).
This method is free of strong modeling assumptions and is also shown to be
robust in the presence of measurement noise and generator parameter
uncertainty.Comment: 13 page
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Diagnostic Applications for Micro-Synchrophasor Measurements
This report articulates and justifies the preliminary selection of diagnostic applications for data from micro-synchrophasors (µPMUs) in electric power distribution systems that will be further studied and developed within the scope of the three-year ARPA-e award titled Micro-synchrophasors for Distribution Systems
A survey of life support system automation and control
The level of automation and control necessary to support advanced life support systems for use in the manned space program is steadily increasing. As the length and complexity of manned missions increase, life support systems must be able to meet new space challenges. Longer, more complex missions create new demands for increased automation, improved sensors, and improved control systems. It is imperative that research in these key areas keep pace with current and future developments in regenerative life support technology. This paper provides an overview of past and present research in the areas of sensor development, automation, and control of life support systems for the manned space program, and it discusses the impact continued research in several key areas will have on the feasibility, operation, and design of future life support systems
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