Fault Identification of UPFC-Compensated Transmission Lines in Complex Microgrids Using an Intelligent Relaying Scheme Based on Discrete Wavelet Transform and ANN Classifier
Date
2018-07-23
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Abstract
Transformation of traditional power infrastructures to modern inter-connected electrical grids has resulted in the emergence of microgrids as modernization of the existing aging transmission and distribution systems. Microgrids allow integration of distributed energy resources (DER) such as wind farms (WF) and may utilize Flexible AC Transmission Systems (FACTS) such as Unified Power Flow Controller (UPFC). FACTS increase power flow capacity of transmission lines while DERs supply additional electric energy. In these systems, current direction, as well as power injections, may change at any time; hence, the protection task is complicated during fault occurrences. The fault data is highly nonlinear and nonstationary, making a conventional distance relay dysfunctional. To fix this, many researchers have used signal processing and soft computing techniques. However, previous works are inadequate in terms of scope and type of fault data acquired from circuits, which usually have simple topologies and are applicable to specific systems. In contrast, this work proposes a single-ended intelligent relaying scheme for high voltage UPFC-Compensated transmission lines in complex interconnected power systems with mesh/loop configurations. This study uses a microgrid model created in Matlab/Simulink, which includes a constant power source, a WF, a steam turbine synchronous generator (STSG), and UPFC for line compensation. Interestingly, most unpredictable in this circuit is the fault signature as it simultaneously combines the UPFC three-phase symmetric response as well as the responses from other interconnected sources. The study uses discrete wavelet transform (DWT) for feature extraction and artificial neuron network (ANN) for feature classification of fault currents. The main objectives are automatic detection and identification of fault type with the best accuracy, reliability, and reduced computational complexity. Furthermore, to analyze the impact of UPFC on fault, the study considers also: (i) circuit without UPFC and (ii) circuit without UPFC & DER. Furthermore, using a two-block ANN consisting of two parallel subclassifiers based on whether the fault involves ground or not, further improved the overall performance suggesting a modular ANN is preferred. Finally, the method achieved an early detection time of less than half cycle of post-fault data that is quite useful for breakers’ fast three-phase tripping operations.
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Keywords
Fault Identification, Fault detection, Fault classification,, Transmission Line Protection, UPFC, UPFC-Compensated, Compensated Transmission Line, Line Compensation with UPFC, Unified Power Flow Controller, UPFC Controller, Line Compensation, Transmission Line Relays, Transmission Line Relaying, Transmission Relaying System, Transmission Line Relaying System, Transmission Line Relaying Scheme, Protective Relaying Scheme, Protection, Intelligent Protective Relaying Scheme, Intelligent Relaying Scheme, Intelligent Protective Relays, Intelligent Protection, Intelligent Protection Scheme, Single-ended Intelligent Protective Relaying, Single-ended Intelligent Protective Relays, Single-ended Intelligent Protective Relaying System, Single-ended Protection System, Single-ended Protection Scheme, One-ended Protection System, One-ended Protection Relays, One-ended Protective Relaying, One-ended Protective Relaying System, One-ended Protective Relaying Scheme, Single Terminal Protective Relaying, Single-terminal Protective Relaying, Single-terminal Protection, Single-terminal Current-based Relay, Single-terminal Current-based Relaying, Discrete Wavelet Transform, ANN Classifier, DWT and ANN Classifier, Protection based on Discrete Wavelet Transform and ANN Classifier, Protection based on DWT and ANN, Relays using DWT and ANN, Relaying Scheme using ANN, Relaying Scheme using DWT, DWT and ANN, DWT-ANN, DWT and ANN Fault, ANN Fault, DWT Fault, DWT & ANN Fault, ANN Calssification, ANN Fault Detection, Microgrid, Microgrid Protection, Complex Microgrid, Complex Microgrid Protection, UPFC in Microgrid, Microgrid using UPFC, Transmission Line Protection in Microgrid, FACTS in Transmission Line, FACTS Compensated Transmission Line, High-Voltage Transmission Line, High-Voltage Transmission Line Protection, Wavlete energy-based protection, Fast Detection of faults, Early detection of fault, Modular Neural Network Fault Classification, Modular ANN Fault Classification, Fault Identification based on ANN, Fault Identification based on Neural Network, Fault classification based on ANN, Fault Identification based on DWT, Fault detection based on DWT, Single-ended Protective Relaying, Single-ended Relaying, Single-ended Protective Relays, Single-ended Relays, Power System Protection, Power System Protective Relaying, Power System, Simulink modelling of microgrid, Simulink model of microgrid, Simulink modelling of power system, Simulink model of power system, Simulink model of test power system, Test Microgrid Model, Test Power System Model, Fault study, Fault studies, Fault Analysis, Transmission Line Fault Analysis, Transmission Line Short Circuit Analysis, Transmission Line Short-Circuit Analysis, Short Circuit Analysis, Short-Circuit Analysis, Transmission Line Fault, Transmission Line Short Circuit, Line Fault
Citation
Rezai, S. (2018). Fault Identification of UPFC-Compensated Transmission Lines in Complex Microgrids Using an Intelligent Relaying Scheme Based on Discrete Wavelet Transform and ANN Classifier (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/32686