Voltage Sag Data Utilization for Distribution Fault Location

Abstract-Fault location in distribution systems is an important function for outage management and service restoration directly impacting feeder reliability. In this paper, a fault location method based on matching calculated voltage sag data and data gathered at some nodes in the network is proposed. A method for characterization of voltage sags is utilized to reduce amount of transferred data. The proposed method can pinpoint fault location precisely, and is applicable to any complex distribution systems with load taps, laterals, and sub-laterals, single-phase loads, as well as networks with heterogeneous lines. The performance of the proposed method is demonstrated on the IEEE 123-node distribution test system via computer simulations in Alternate Transients Program software

ADVANCED ASSESSMENT OF THE POWER QUALITY EVENTS

Abstract: This paper introduces a new concept of advanced power quality assessment. The concept is implemented using the software for event detection, classification and characterization. The role of the modeling and simulation in the power quality assessment is also discussed. The use of the field recorded data and simulated data in the equipment performance analysis is outlined. All the mentioned approaches are suggested for power quality assessment use when setting up and verifying the power quality contracts

Data Integration and Information Exchange for Enhanced Control and Protection of Power Systems

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Sensitivity analysis on the probabilistic maintenance model of circuit breaker

Abstract--Catastrophic failures of circuit breakers result in high cost associated with loss of load and component replacement. The probability of such failures can be reduced using maintenance procedures. Probabilistic models are needed to estimate failure rate, perform cost benefit analysis and arrive at an optimal maintenance strategy that balances the cost of maintenance with reduction in cost of failures. A probabilistic maintenance model, introduced earlier for circuit breakers, is implemented in this paper. The model parameters are mean time in each stage, inspection rate of each stage, and probabilities of transition from one stage to others. Sensitivity analysis of model parameters is done to establish cost-effective maintenance process. The analysis covers mean time to first failure, probability of failure, maintenance cost, inspection cost, and failure cost. Simulation results are presented

Impact Analysis of Network Topology Change on Transmission Distance Relay Settings

Abstract-One big challenge raised by frequent topology change in today's power system is assessing the system protection security and dependability afterwards. This paper reviews the setting algorithm for the distance relays and proposes an automated setting calculation module. The calculation procedure is broken down into blocks which could be processed in parallel in order to improve the computation speed. The module could be used to assess the system protection vulnerabilities following a topology change in instances when multiple switching actions are done in response to occurrence of cascading faults or as a result of intentional control action. The module performance is tested on New England 39-bus and IEEE 118-bus systems. A sensitivity analysis in the form of N-2 contingency impact on the network relay settings is conducted on both test systems. Keywords-Power system protection security and dependability, N-2 contingency, phase distance settings, relay ranking, topology control, vulnerability

Optimal Estimate of Transmission Line Fault Location Considering Measurement Errors

Abstract-Various transmission line fault location algorithms have been proposed in the past depending on the measurements available. These algorithms perform well when the measurements utilized are accurate; they may yield erroneous results when the measurements contain considerable errors. In some cases, there are redundant measurements available for fault location purposes, and it may be possible to design an optimal estimator for the fault location based on nonlinear estimation theories. This paper aims at proposing a possible method for deriving an optimal estimate of the fault location that is capable of detecting and identifying the bad measurement data, minimizing the impacts of the measurement errors and thus significantly improving the fault location accuracy. The solution is based on the distributed parameter line model and thus fully considers the effects of shut capacitances of the line. Since field data are not available, case studies based on simulated data are presented for demonstrating the effectiveness of the new method. Index Terms-Bad measurement detection and identification, distributed parameter line model, fault location, nonlinear estimation theory, optimal estimator

Data Integration and Information Exchange for Enhanced Control and

One issue that did not get adequate attention regarding control and protection of power systems in the past is the data integration and information exchange. The traditional approaches assume that each function such as protection, control, monitoring, and maintenance are supported by a separate infrastructure of recording instruments and/or controllers for obtaining and processing data. With introduction of the new computer-based equipment for control and protection in the mid eighties, the integration of data and information exchange were possible, but not explored. This paper indicates what are the improvements and benefits that can be obtained by integrating the data and exchanging information among control and protection as well as system-wide monitoring and control functions

Detection of Symmetrical Faults by Distance Relays During Power Swings

Abstract-For maintaining security of distance relays, power swing blocking is necessary to prevent unintended operation under power swings. To be dependable, distance relays must operate whenever a fault occurs. Therefore, detecting faults during power swings is an important issue since the relay should be able to differentiate the fault condition and not be blocked during that time. This paper presents a new method for detecting a symmetrical fault during a power swing, based on extracting components of the current waveform using the Prony method. The merit of the method is demonstrated by simulating different faults during power swing conditions using the Alternate Transients Program version of the Electromagnetic Transients Program. Index Terms-Distance relay, power swing, prony method, symmetrical fault

Optimization of Electric Vehicle Movement for Efficient Energy Consumption

Abstract-This paper focuses on the development of computational optimization algorithm to provide energy-based driving guidance for electric vehicle (EV) drivers to use the limited resource efficiently. The proposed efficiency improving strategy that minimizes total energy consumption according to various driving scenarios is demonstrated and analyzed. Several factors such as regenerative energy coefficient, stop-and-go frequency, inclination of ground, wind speed, etc. have been taken into consideration in the case studies