Application of Immune-Based Optimization Method for Fault-Section

A Parameter Identification Technique for Metal-Oxide Surge Arrester Models Li, H.J.; Birlasekaran, S.; Choi, S.S. Author Afflliation: Nanyang Technological University, Singapore Abstract: A simple numerical technique to identify the parameters of metal-oxide arrester models is described. Using measured arrester voltage obtained under impulse test conditions, the arrester parameters are determined using an optimization technique. The validity and the accuracy of the model are then assessed by comparing the predicted against the measured values of arrester energy, initial slope, residual voltage, and the overall deviation. Application of the arrester model on network system studies is illustrated. Keywords: Insulation coordination, metal-oxide surge arrester, optimization method, parameter identification. Preprint Order Number: PE-367PRD (01-2002) Discussion Deadline: June 2002

Statistical Classifitcation of Major Event Days in Distribution System Reliability Christie, R.D. Author Affiliation: University of Washington, Seattle, Washington, USA Abstract: This paper describes a capacitor commutated converter (CCC) model suitable for power flow and transient stability studies. The CCC control structure and important operational details are described. The practical advantages of the CCC as compared to the conventional HVDC converter are discussed. Results are presented for power flow, power system stability, small signal analysis, and control design studies. These results clearly demonstrate the superior performance of a CCC link, when connected to a very weak ac system. Keywords: HVDC transmission, capacitor commutated converter, transient stability, power flow, linear analysis. Preprint Order Number: PE-471PRD (01-2002) Discussion Deadline: June 2002

Transmission and Distribution Application of Immune-Based Optimization Method for Fault-Section Estimation in a Distribution System

Determination of Allowable Penetration Levels of Distributed Generation Resources Based on Harmonic Limit Consideration Bhowmik, A.; Maitra, A.; Halpin, S.M.; Schatz, J.E.

Huang, S.J. Author Affiliation: National Cheng Kung University, Tainan, Taiwan Abstract: In this paper, an immune algorithm (IA)-based optimization approach for the fault-section estimation of a distribution system is proposed. To apply the method to solve this estimation problem, each section of power system model can be considered as an antibody. Through the immunology evolution, an antibody that most fits the antigen of concern becomes the solution. An affinity calculation has been employed in this computation process to measure the combination intensity. As this method can operate the population of antibodies simultaneously, the process stagnation can be better prevented. The proposed approach has been tested on Taiwan Power System (Taipower) through the utility data. Test results demonstrated the feasibility and effectiveness of the method for the applications. Keywords: Fault-section estimation, immune algorithm, optimization. Preprint Order Number: PE-356PRD (01-2002) Discussion Deadline: June 2002

Author Affiliation: Mississippi State University, Mississoppi, USA; Southern Company Services, Birmingham, Alabama, USA Abstract: Analytical methods are formulated in this paper to predict allowable distributed generation resources on a radial distribution feeder before voltage harmonic limits (as specified in IEEE 519-1992) are exceeded. The final result is a determination of allowable penetration levels of distributed generation resources for a range of distribution feeders. Closed-form equations are derived for typical feeder designs and different load allocation pattems. These equations are validated with conventional harmonic analysis simulations that show that the closed-form equation predictions are slightly conservative. These methods will serve as efficient tools for power system planning and design without requiring exhaustive studies to determine the impact of distributed generation resources. Keywords: Harmonic limits, distributed generation Preprint Order Number: PE-015PRD (01-2002) Discussion Deadline: June 2002

Operation of a DSTATCOM in Voltage Control Mode Mishra, M.K.; Ghosh, A.; Joshi, A. Author Affiliation: Indian Institute of Technology, Kanpur, India Abstract: This paper presents the operating principles of a distribution static compensator (DSTATCOM) that is used to maintain the voltage of a distribution bus. A three-phase, four-wire distribution system is assumed in this study. A three-phase bridge inverter circuit that is supplied by two neutral-clamped dc storage capacitors realizes the DSTATCOM. Three filter capacitors, one for each phase, are connected in parallel with the DSTATCOM to eliminate high-frequency switching components. The voltage across the filter capacitor is controlled by a dead-beat controller to maintain the ac bus voltage. The magnitude of the bus voltage is chosen as a nominal value, i.e., 1.0 per unit, while its phase angle is obtained through a feedback loop that maintains the voltage across the dc storage capacitors. Through detailed simulation and experimental results it has been shown that the DSTATCOM can maintain the voltage against any unbalance and distortion in either the load or supply side. Keywords: DSTATCOM, voltage regulation, deadbeat control, neutral clamped inverter. Preprint Order Number: PE-523PRD (01-2002) Discussion Deadline: June 2002 IEEE Power Engineering Review, April 2002

Linearization of Chromatic Change in a Polychromatic Current Transformer Aspey, R.A.; Brazier, K.J.; Li, G.D.; Spencer, J.W

Author Affiliation: University of Wales, Aberystwyth, Ceredigion; Liverpool University, Liverpool Abstract: This paper introduces permittivity shielding. Permittivity shielding enables the measurement of voltage with very few electric field sensors. Voltage sensor designs using permittivity shielding can exploit existing optical sensor technology without the need for the expensive and potentially hazardous insulation found in many modem optical voltage transducers. Numerical simulations demonstrate that a voltage sensor consisting of 100 MQ2 shielding and six electric field sensors, or less, mounted inside an "off-the-shelf' stand-off insulator can achieve Class 1 metering accuracies (< 0.3 % magnitude error and < 8 min phase error) even in the presence of strong stray field effects. Keywords: High-voltage techniques, transducers, electric fields, electric field measurement, electric field effects, voltage measurement, optics, permittivity, dielectric materials, shielding. Preprint Order Number: PE-592PRD (01-2002) Discussion Deadline: June 2002 79