Advanced numerical methods for simulating nonlinear multirate lumped parameter models.

674 Pages·5.3 MB·en_US

by  Doerry, Norbert Henry.

ADVANCED NUMERICAL METHODS FOR
SIMULATING NONLINEAR MULTIRATE
LUMPED PARAMETER MODELS
by
NORBERT HENRYpOERRY
Naval Engineer
S.M. Electrical Engineering and Computer Science
Massachusetts Institute ofTechnology
(1989)
B.S. Electrical Engineering
United States Naval Academy
(1983)
SUBMITTED TO THE DEPARTMENT OF
OCEAN ENGINEERING
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
in the field of
NAVAL ELECTRICAL POWER SYSTEMS
at the
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
May 1991
©
Norbert H. Doerry 1991
Signature ofAuthor
Department ofOcean Engineering
12 May 1991
Certified by
James L. Kirtley, Thesis Supervisor
Associate Professor of Electrical Engineering
Certified by
Marija Die, Thesis Supervisor
Senior Research Engineer,
Department ofElectrical Engineering and Computer Science
Accepted by
A. Douglas Carmichael, Chairman
Ocean Engineering Departmental Graduate Committee
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ADVANCED NUMERICAL METHODS FOR SIMULATING
NONLINEAR
MULTIRATE LUMPED PARAMETER MODELS
by
Norbert H. Doerry
Submitted on May 12, 1991 to the Department of Ocean Engineering in partial fulfillment of
the requirements for the degree of Doctor of Philosophy in the field of Naval Electrical
Power Systems.
ABSTRACT
Naval shipboard electric power systems are transitioning from the relatively simple
distribution of ship service electric power to extremely complex integrated electric drive
(IED) systems. The optimal design of warships employing IED is presently hampered by the
lack of existing simulation computer tools for analyzing the highly coupled and controlled
electro-mechanical systems characteristic of IED. As a first step in the development of a
viable computer simulation tool, the numerical algorithm testing program WAVESIM was
created.
WAVESIM
The key contributions of are the systematic treatment of waveforms as an
abstract data type, the development of the terminal description of devices, and the use of
structuraljacobians in system reduction.
WAVESIM represents variables by waveforms consisting of a vector of coefficients
and a waveform type code indicating how the coefficients should be interpreted. The
principal advantage of using waveforms over conventional discrete point methods is the
avoidance of unstable integration techniques since for most waveform types, integration and
differentiation are linear matrix operations.
WAVESIM
Devices are described in by relationships between terminal interface
variables. WAVESIM recognizes two types of terminals: normal terminals having both
potential and flow variables, and information terminals having only a potential variable. In
WAVESIM
this manner, can simulate processes involving both energy transfer and control
signals.
WAVESIM
extends the structural jacobian matrix concept to reflect the properties of
the dependence of system equations on system variables. The system structural jacobian
matrix is constructed from the constitutive device structural jacobian matrices and is used to
identfiy a sequence of smaller blocks when can be solved consecutively for all the system
variables.
To demonstrate and verify the capabilities of WAVESIM, several simulations were
WAVESIM
conducted. In all simulations, provide results matching data generated by other
simulation methods.
Thesis Supervisor: James L. Kirtley, Associate Professor of Electrical Engineering
Thesis Supervisor: Marija Ilic, Senior Research Engineer, Department of Electrical
Engineering and Computer Science
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The author hereby grants to the United States Government and the Massachusetts Institute of
Technology permission to reproduce and distribute copies of this thesis document in whole
or in part.
Norbert Henry Doerry
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