An Improved Branch Exchange Algorithm ... Keywords: Power system distribution planning, branch exchange, ... the principles of multiagent system theory.
A Methodology for Optimal Power Dispatch Under a Pool-Bilateral Market Fernandes, Thelma S.P; Almeida, Katia C. Author Affiliation: Federal University of Parana; Univesidade Federal de Santa Catarina. Abstract: This work proposes an optimization model for the power dispatch under a pool-bilateral market. In it, all transactions and also the power traded in the spot market are separated into different networks according to the corresponding current injections. Using the superposition principle (SP), a set of network equations is assigned to every transaction and also to the power injections related to the pool (spot market). The model comprises all network equations and also inequalities representing operational limits. A primal-dual interior-point method is used for the resolution of the optimization problem. The line currents, complex voltages, and power generation associated with every transaction and with the spot market are obtained. Results are presented for a 5 bus and the IEEE 118 bus systems. Keywords: Optimal power dispatch, pool-bilateral markets, primal-dual interior-point method, superposition principle. Preprint Order Number: PE-443PRS (06-2002) Discussion Deadline: November 2002
An Improved Branch Exchange Algorithm for Large Scale Distribution Network Planning Miguez, E.; Cidras, J.; Diaz-Dorado, E.; Garcia-Dornelas, J.L. Author Affiliation: Universidade De Vigo.
Abstract: Design of optimal layout for medium-voltage (MV) power networks is a common issue in electrical distribution planning. Technical constraints (radial structure, voltage drops, and equipment capacity) and reliability limits must be fulfilled. The function for minimizing includes investments, power losses, and quality of supply costs. We present an improved algorithm based on a branch exchange technique to solve large-scale problems. A heuristic algorithm for solving a Euclidean Steiner problem is used to improve the network by including transshipment nodes. Keywords: Power system distribution planning, branch exchange, network design, Steiner tree probleans. Preprint Order Number: PE-046PRS (06-2002) Discussion Deadline: November 2002
Power System Communications Characterization and Modeling of In-Building Power Lines for High-Speed Data Transmission Tang, L.T.; So, PL.; Gunawan, E.; Guan, YL.; Chen, Shiun; Lie, Tjing T. Author Affiliation: Nanyang Technological University. Abstract: This paper analyzes the characteristics of power lines in the Singapore residential network in order to develop a channel model suitable to simulate its behavior for high-speed data transmission. The channel model, which describes the transfer function and noise characteristics of typical in-building power line channels in a frequency band from 1 to 10 MHz, is developed and tested through software simulation and hardware implementation. The transfer function is described by an echo model, and the noise spectrum is derived statistically from measurements on actual power lines. Some measurement results on power line impedance, noise, and attenuation are presented. The results are based on measurements between line and neutral conductors in a 230 V power line network. From the results obtained so far, the impedance, noise, and attenuation of power lines exhibit variations with frequency, time, and location. Keywords: Power line communications, measurements, characterization, channel model. Preprint Order Number: PE-097PRD (06-2002) Discussion Deadline: November 2002 58
Power System Dynamic Performance Direct Methods for Transient Stability Assessment in Power Systems Comprising Controilable Series Devices Gabrijel, Uros; Mihalic, Rafael Author Affiliation: University of Ljubljana. Abstract: New energy functions that incorporate the action of controllable series devices (CSD) are presented. They make it possible for the direct method to acquire the critical clearing time (COT) of a single-machine infinite-bus (SMIB) power system and the certain series Flexible AC Transmission Systems (FACTS) devices directly. Dealing with this matter, optimal control strategies for the controllable series compensation (CSC) and the static synchronous series compensator (SSSC) are first derived. These and later tasks make use of the advantages of mathematical models that represent the controllable parameter of a FACTS device in relation to the transmitted real power through the given line. Using the derived control laws and some assumptions, Lyapunov-like energy functions were carried out. The results of a numerical example attained by a direct method and a digital simulation are shown to be promising. The final consideration suggests where future efforts should be directed. Keywords: FACTS, controllable series devices, SSSC, CSC, control strategy, Lyapunov energy function, critical clearing time, transient stability. Preprint Order Number: PE-474PRS (06-2002) Discussion Deadline: November 2002 Power System Stability Agents Using Robust Wide-Area Control Ni, Hui; Heydt, Gerald T.; Mili, Lamine Author Affiliation: Arizona State University; Alexandria Research Institute, Virginia Tech. Abstract: Conventional power system stabilizers (PSS) are major local damping controllers acting through generator excitation systems.
There are studies that suggest that remote signals could si-crease damping beyond that attainable by local signals. A supervisory level power system stabilizer (SPSS) using wide-area measurements is proposed. The robustness of the proposed controller is capable of compensating for the nonlinear dynamic operation of power systems and uncertain disturbances. The coordination of the robust SPSSs and local PSSs is implemented based on the principles of multiagent system theory. This theory is an active branch of applications in distributed artificial intelligence (DAI). The performance of the robust controller as a power system stability agent is studied using a 29-machine 179-bus power system example. Keywords: Robust control, wide area control, power system stabilizer, multiagent system, power system damping. Preprint Order Number: PE-516PRS (06-2002) Discussion Deadline: November 2002
Modeling of Wind Turbines for Power System Studies Petru, Tomas; Thiringer, Torbjorn Author Affiliation: Chalmers University of Technology. Abstract: The modeling of wind turbines for power system studies is investigated. Complexities of various parts of a wind turbine model, such as aerodynamic conversion, drive train, and generator representation, are analyzed. The results are verified by field measurements made on a stall-regulated fixed-speed wind turbine. The modeling focuses on deriving a representation that is suitable for use in grid simulation programs. Keywords: Wind turbine, power quality, model, modeling, grid interaction. Preprint Order Number: PE-617PRS (06-2002) Discussion Deadline: November 2002 IEEE Power Engineering Review, September 2002
