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| 99-01 | A Virtual Environment for Interactive Visualization of Power System Economic and Security Information
Simulation and analysis of power
systems often involves modeling
extremely complex systems. This is
particularly true when the model
involves not just the electrical power
system, but also other networks layered
on top of the power system, such as the
accompanying financial transactions.
Such layered networks can often involve
interactions that are not at all
obvious. Interactive visualization can
be a very effective means for
determining otherwise hidden
relationships between various elements
in the network. This paper describes a
3D virtual environment developed to
allow users to interactively visualize
such information and relationships.
The paper describes the architecture
used to develop this environment, and
then provides several examples of how
the environment is used to provide an
interactive visualization of power
system economic and security
information.
| Thomas J Overbye, Raymond P. Klump, Jamie D. Weber | 3/30/1999 | 430.0k | PDF |
| 99-02 | THE IMPACT OF GENERATION MIX ON PLACEMENT OF STATIC VAR COMPENSATORS
This paper looks at the problem of
placing Static Var Compensators to
provide
maximum transfer capability for all
possible generation mixes. The margin to
low
voltage limit is one of the quantities
used to determine power system transfer
capability. A fast method for finding
the location of SVC systems that will
have the
greatest impact on the low voltage
margin will be shown. The IEEE 24 bus
system
will be used to demonstrate this method
over a wide range of generation
patterns.
| Robert H. Lasseter, Ronghai Wang | 5/21/1999 | 98.8k | PDF |
| 99-03 | Optimal Power Flow Formulation in Market of Retail Wheeling
Power system deregulation along with
retail wheeling was proposed in
legislation for
the future power system operation.
Retail wheeling implies customers have
more
choices. One important option is the
power supplier providing cheaper power.
In this
paper we introduce new concepts of
generation sets and load sets to model
the
behavior of power supply and load
distribution in the new retail wheeling
market.
Formation of optimal power flow (OPF)
problem, in which the public interests
are
maximized, is demonstrated.. IEEE-14 bus
system is used as an example.
| Taiyou Yong, Robert Lasseter | 5/21/1999 | 35.4k | PDF |
| 99-04 | Coordination of Excitation and Governing Control Based on Fuzzy Logic
In deregulated power systems,
competition could push the system near
its
security limit. The issue of power
system stability is becoming more
crucial. The
excitation and governing controls of
generator play an important role in
improving the
dynamic and transient stability of power
system. Typically the excitation control
and
governing control are designed
independently. In this paper, we present
a fuzzy logic
based method for the excitation control
and governing control. Fuzzy logic is
applied
to generate two compensating signals to
modify the controls during system
disturbances. A single machine to
infinite bus system is applied in
simulation. The
oscillation of internal generator angles
is observed to indicate the good
performance of
proposed control scheme.
| Taiyou Yong, Robert H. Lasseter, Wenjin Cui | 5/21/1999 | 101.5k | PDF |
| 99-05 | Designing Cost Effective Demand Management Contracts using Game Theory
Demand relief from customers can help a
utility solve a variety of problems.
There exist all sorts of different
demand management programs that
utilities use. A critical issue is the
incentive paid to the customer to
participate in demand management
programs and provide load relief. The
utility has to design cost effective
yet attractive demand management
contracts. The main goal is to get load
relief when needed. If the contracts are
designed to be cost effective they can
help the utility reduce costs. Customers
sign up for programs when the benefits
they derive in the form of up front
payments and interruption payments
exceed their cost of interruption. In
order to design such contracts,
mechanism design with revelation
principle is adopted from Game Theory
and applied to the interaction between a
utility and its customers.The idea
behind mechanism design is to design an
incentive structure that encourages
customers to sign up for the right
contract and reveal their true value of
power (and thus, the value of power
interruptibility).
| Murat Fahrioglu and Fernando L. Alvarado | 6/8/1999 | 108.9k | PDF |
| 99-06 | Using Utility Information to Calibrate Customer Demand Management Behavior Models
In times of stress customers can help a
utility by means of voluntary demand
management programs if they are offered
the right incentives. The incentives
offered can be optimized if the utility
can estimate the outage or substitution
costs of its customers. This report
illustrates how existing utility data
can be used to predict customer demand
management behavior. More specifically,
it shows how estimated customer cost
functions can be calibrated to help in
designing efficient demand management
contracts. | Murat Fahrioglu and Fernando L. Alvarado | 6/10/1999 | 123.8k | PDF |
| 99-07 | Detecting and Improving the Vulnerable Links in the Power Network:Part I
We simulate, via a variance reduction
scheme called importance sampling, rare
events involving generator trips and
incorrect zone three relay operations
while monitoring the frequency,
generation, and load deviation. We have
studied the significance of reducing the
probability of a false relay operations
in the weak links to determine its
effect
on the rest of the network and prove
that
reducing the probability of hidden
failures does not pose negative side
effects on the system security. Given a
system and economic conditions, it is
useful to know where investments such as
microprocessor relays will be most
effective. It is our contention that
the
improvements in protection in these weak
links will allow the ISO to make better
future financial investments.
| Koeunyi Bae and James Thorp | 6/16/1999 | 207.6k | PDF |
| 99-08 | Suggested Analytic Approach to TransmissionReliability Margin; Draft Report June 1999
Transmission Reliability Margin (TRM) is
the component of available transfer
capability that accounts for
uncertainties and safety margins. We
suggest an analytic framework for TRM
calculation using transfer capability
sensitivity formulas and a
probabilistic characterization of the
various uncertainties.
Preliminary results on a simple example
show how we plan to test the TRM
calculation and validate it with a Monte
Carlo method.
This draft report is produced in order
to seek comment from PSerc members on
the practicality and usefulness of this
approach to TRM.
| Jianfeng Zhang, Ian Dobson, Fernando L. Alvarado | 7/5/1999 | 102.5k | PDF |
| 99-09 | Fast Determination of Simultaneous Available Transfer Capability (ATC)
This paper proposes a novel fast
computational method to determine the
simultaneous power available transfer
capability (ATC) in a power system.
This method consists of a fast
estimation algorithm and a constrained
power flow iteration. The ATC limiting
factors considered in the method are:
line thermal limits, bus voltage
limits, and generator reactive power
limits. When combined with the first
line contingency considerations, this
method will give the fastest ATC
computing. The feature of this method
is that it uses only one steady state
power flow result for the fast
estimation algorithm. Without further
time consuming power flow iterations,
it is the fastest estimation algorithm
available. Based on the fast
estimation, with a few more constrained
power flow iterations, precise ATC
value can be obtained. This method can
be used to improve the speed of many
available ATC programs. Especially, it
may be used in addition to the widely
used DC power flow program or simply
replace it to provide additional
voltage and var information, since DC
power flow generally ignore voltage or
var problems. This method can help the
independent system operator (ISO) to
determine the validity of the bidding
results in an open access deregulated
electricity market when timely ATC
information is very important. It can
also help the power market participants
to place bids strategically when
congestion happens. | Ronghai Wang, Robert H. Lasseter, Jiangping Meng, Fernando L. Alvarado | 7/23/1999 | 60.0k | PDF |
| 99-10 | APPLICATION OF OPTIMAL MULTIPLIER METHOD IN WEIGHTED LEAST-SQUARES STATE ESTIMATION PART I:THEORY
Standard algorithms for state estimation
may be viewed as quasi-Newton's methods
applied to the first order optimality
conditions of a least squares
minimization problem. Previous work in
the literature has documented the
(somewhat surprising) fact that when a
full Newton's method is applied to the
same formulation, convergence properties
are far worse than the quasi-Newton's
method, until the iterates reach an
EXTREMELY small neighborhood of the
solution. Motivated by these results,
and by availability of efficient
algorithms to compute higher order
derivatives necessary in an exact Newton
formulation, this paper proposes several
Newton's method variants to improve
state estimator convergence. Benchmarks
for the IEEE 118 and 300 bus test
systems are provided, with comparisons
against classical normal equation
method, Hatchel's method, and QR
algorithms. In these benchmark
examples, the new algorithms developed
show more reliable convergence for
ill-conditioned cases, while making
minimal sacrifices in computational
efficiency for well-conditioned cases. | Jianping Meng, Christopher L. DeMarco | 7/23/1999 | 134.6k | PDF |
| 99-11 | APPLICATION OF OPTIMAL MULTIPLIER METHOD IN WEIGHTED LEAST-SQUARES STATE ESTIMATION PART II: SIMULATION
Standard algorithms for state estimation
may be viewed as quasi-Newton's methods
applied to the first order optimality
conditions of a least squares
minimization problem. Previous work in
the literature has documented the
(somewhat surprising) fact that when a
full Newton's method is applied to the
same formulation, convergence properties
are far worse than the quasi-Newton's
method, until the iterates reach an
EXTREMELY small neighborhood of the
solution. Motivated by these results,
and by availability of efficient
algorithms to compute higher order
derivatives necessary in an exact Newton
formulation, the companion paper
proposes several Newton's method
variants to improve state estimator
convergence. In this paper Benchmarks
for the IEEE 118 and 300 bus test
systems are provided, with comparisons
against classical normal equations,
Hatchel's method, and QR algorithms. In
these benchmark examples, the new
algorithms developed show more reliable
convergence for ill-conditioned cases,
while making minimal sacrifices in
computational efficiency for
well-conditioned cases. | Jianping Meng, Christopher L. DeMarco | 7/23/1999 | 162.2k | PDF |
| 99-12 | Visualization of Power System Data
Effective power system operation
requires power system engineers and
operators to analyze vast amounts of
information. In systems containing
thousands of buses, a key challenge is
to present this data in a form such
that the user can assess the state of
the system in an intuitive and quick
man-ner. This is particularly true when
trying to analyze relationships between
actual network power flows, the
scheduled power flows, and the capacity
of the transmission system. With
restructuring and the move towards
having a single entity, such as an
independent system operator or pool,
operate a much larger system, this need
has become more acute. This paper
presents several power system
visualization techniques to help in
this task. These techniques include
animation of power system flow values,
contouring of bus and transmission line
flow values, data aggregation
techniques and virtual reality data
visualization. | Thomas J. Overbye, Jamie D. Weber | 10/1/1999 | 429.4k | PDF |
| 99-13 | Initial evidence for self-organized criticality in electric power system blackouts
We examine correlations in a time series
of electric power system blackout sizes
using scaled window variance analysis
and R/S statistics. The data shows some
evidence of long time correlations and
has Hurst exponent near 0.7. Large
blackouts tend to correlate with further
large blackouts after a long time
interval. Similar effects are also
observed in many other complex systems
exhibiting self-organized criticality.
We discuss this initial evidence and
possible explanations for self-organized
criticality in power systems blackouts.
Self-organized criticality, if fully
confirmed in power systems, would
suggest new approaches to understanding
and possibly controlling blackouts.
| Ben Carreras, David Newman, Ian Dobson, Bruce Poole | 10/1/1999 | 71.2k | PDF |
| 99-14 | Assessment of Transmission Constraint Costs: Northeast U.S. Case Study
This paper provides a methodology to
examine the impact of transmission
constraints on the efficient operation
of large scale power markets. The
Northeast U.S. is presented as a case
study. A system model was first
constructed using the publicly
available U.S. Federal Energy
Regulatory Commission (FERC) Form 715
filings to provide a detailed
representation of the transmission
system. FERC Form 1 data and
information from the U.S. Energy
Information Administration's (EIA)
National Energy Modeling System model
were used to represent generator
costs. An optimal power flow (OPF) was
then used to optimally dispatch a large
system consisting of the New England
Region (NEPOOL), New York (NYPP), and
the NERC MAAC and ECAR regions, both
under base case and modified
conditions. Using the OPF results, the
costs associated with transmission
constraints are determined. Finally,
given the large amount of data
generated by these studies, methods for
the efficient visualization of the
results are also discussed. | Tom Overbye, Doug Hale, Tom Leckey, Jamie Weber | 10/5/1999 | 1.0M | PDF |
| 99-15 | Sensitivity of transfer capability margins with a fast formula
Bulk power transfers in electric power
systems are limited by transmission
network security. Transfer capability
measures the maximum power transfer
permissible under certain assumptions.
Once a transfer capability has been
computed for one set of assumptions, it
is useful to quickly estimate the effect
on the transfer capability of modifying
those assumptions.
This paper presents a computationally
efficient formula for the first order
sensitivity of the transfer capability
with respect to the variation of any
parameters. The sensitivity formula is
very fast to evaluate. The approach is
consistent with the current industrial
practice of using DC load flow models
and
significantly generalizes that practice
to more detailed AC power system models
that include voltage and VAR limits. The
computation is illustrated and tested on
a 3357 bus power system.
This paper is a preprint from the NSF
ATC
project.
| Scott Greene, Ian Dobson, Fernando Alvarado | 12/30/1999 | 90.8k | PDF |
| 99-16 | Reactive Power Market Power
This paper was presented at the
IEEE PES
Winter Meeting. Market power refers
to
conditions where the
providers of a service can
consistently
charge prices
above those that would be
established by
a
competitive market. There are many
well
known definitions
of market power, including indices
intended to quantify
the degree of market concentration of
energy supplies. This paper explores
a
method by which one
of the standard indices in market
power
analysis (the
Herfindahl-Hirschman Index) can be
used
to measure
reactive power market concentration.
The
proposed
method is illustrated by means of a
simple example. | F. Alvarado, T. Overbye and P. Sauer | 6/13/1999 | 81.3k | PDF |
| 99-17 | Solving Power Flow Problems with a Matlab Implementation of the Power System Applications Data Dictionary
This Word file uses a subset of the
Power System Data Dictionary structures
to implement a complete "vanilla"
power flow along with a few more
capabilities. It is designed so the
examples can be executed by "cut and
paste" from the Word document directly
to Matlab. | Fernando L. Alvarado | 1/20/1999 | 84.5k | DOC |
| 99-18 | A Web-Based Platform for Experimental Investigation of Electric Power Auctions
This paper describes the architecture and uses of an Internet based software platform called PowerWeb. PowerWeb was designed and implemented as a simulation environment for evaluating various power exchange auction markets through experimental investigation. It is designed to host simulations of a competitive “day-ahead” electric energy market in which the participants interact by submitting bids or offers into a market via a web-based user interface. The PowerWeb environment is meant to be flexible so as to allow investigation of various market mechanisms. In this paper we describe its interactive, distributed and web-based character.
Decision Support Systems, Vol. 24, Nos. 3&4, January 1999. Uploaded: June 27, 2006. | R. Zimmerman, R. Thomas, D. Gan, C. Murillo-Sanchez | 6/27/2006 | 533.8k | PDF |
| 99-19 | A Uniform Price Auction with Locational Price Adjustments for Competitive Electricity Markets
Competitive electricity markets which rely on centralized dispatch require a mechanism to solicit offers from competing generators. Ideally, such an auction mechanism provides incentives to submit offers equal to the marginal cost of generation for each generator. Economic theory suggests that the Uniform Price auction is an appropriate institution. However, an efficient implementation of this auction in an electricity context requires that the offers used in the auction reflect the appropriate locational price adjustments for transmission losses and congestion. This paper describes a uniform price auction that incorporates locational price adjustments on a Web-based platform suitable for experimentation. Preliminary results show dramatically different price and revenue results when compared with a simple continuous Discriminative auction. q1998 Elsevier Science Ltd. All rights reserved.
Electric Power and Energy Systems, Vol. 21, 1999. Uploaded: June 27, 2006. | R. Ethier, R. Zimmerman, T. Mount, W. Schulze, R. Thomas | 6/27/2006 | 533.1k | PDF |
| 99-20 | Thermal Unit Commitment with Nonlinear Power Flow Constraints
A formulation of the thermal unit commitment problem including nonlinear power flow constraints is presented, making the use of more realistic constraint models possible. It also allows potential VAr production to be sued as a criterion for the commitment of generators in strategic locations of the network. The Lagrangian Relaxation framework and a variable duplication technique are employed, permitting exploitation of the separation structure of the dual cost. Some results for small to medium-sized systems are reported.
IEEE Power Engineering Society Winter Meeting, Vol. 1, pp. 484-489. Uploaded: June 27, 2006. | C. Murillo-Sanchez, R. Thomas | 6/27/2006 | 467.0k | PDF |
