Juan José Mora Flórez ( J. Mora-Florez ) | Universidad Tecnológica de Pereira (original) (raw)

Papers by Juan José Mora Flórez ( J. Mora-Florez )

Research paper thumbnail of Application of Distance Protection on Active Distribution Networks: A Quantitative Comparison

Research paper thumbnail of Implementation analysis for grid-forming converter considering primary energy source effect

Research paper thumbnail of Clustering Techniques Performance for the Coordination of Adaptive Overcurrent Protections

Research paper thumbnail of Automatic Load Model Selection Based on Machine Learning Algorithms

IEEE Access

Technology development and decentralized operations create changes in conventional electric syste... more Technology development and decentralized operations create changes in conventional electric systems, where load modeling has been a challenge in dynamic analysis. Consequently, accurate dynamic load models are required to ensure the quality of the studies in current systems. This paper presents an automatic strategy based on clustering, classification, and optimization algorithms, to obtain the load models in the case of several system operating conditions. The obtained load models are helpful for the planning, operation, and protection of electric power systems. The proposed approach validation is performed using the IEEE 14-bus test system, where high performance is obtained. The average obtained cross-validation error for the load models assigned to the 13 clusters of disturbances is 5.36 × 10 −3. The cross-validation error is used as a tolerance value to determine when an online assigned load model is suitable to represent the measured disturbance. The proposed tests show the strategy's capabilities of defining the load model online, making this approach suitable for field applications. INDEX TERMS Dynamic load modeling, generalization capability, machine learning, parameter identification.

Research paper thumbnail of Performance analysis of a learning structured fault locator for distribution systems in the case of polluted inputs

Electric Power Systems Research, 2019

Waveform distortion and the service continuity are the two main aspects which define the power qu... more Waveform distortion and the service continuity are the two main aspects which define the power quality; in the last, the fault location plays a fundamental role. Considering the requirement of reliable tools to improve the distribution system operation, this document analyses the confidence of a fault locator approach. This paper initially presents the adjusting and the validation methodology used to develop a fault locator, and also its performance is analysed by considering different distorted measurements as inputs. The approach here presented is a learning based fault locator (LBFL), specially customized for distribution systems, whose core are the Support Vector Machines (SVM). The LBFL is tested in an unbalanced 34.5 kV distribution feeder considering diverse operating conditions and fault scenarios, which include several fault resistances, locations, and common disturbances on the voltage and current input signals. From the tests, the lowest LBFL performance is 96.5% in such cases of not distorted measurements of voltage and current. In the case of considering polluted inputs, the worse performance is obtained in the case of distortions caused by low sampling frequency, current transformer saturation and high harmonic distortion.

Research paper thumbnail of Fault Location in Power Distribution Systems Using a Learning Algorithm for Multivariable Data Analysis

IEEE Transactions on Power Delivery, 2007

This paper proposes alternatives to improve the electric power service continuity using the learn... more This paper proposes alternatives to improve the electric power service continuity using the learning algorithm for multivariable data analysis (LAMDA) classification technique to locate faults in power distribution systems. In this paper, the current and voltage waveforms measured during fault events are characterized to obtain a set of descriptors. These sets are analyzed by using the projection pursuit exploratory data

Research paper thumbnail of Data-driven topology detector for self-healing strategies in Active Distribution Networks

Research paper thumbnail of Elimination of Multiple Estimation for Fault Location in Radial Power Systems by Using Fundamental Single-End Measurements

IEEE Transactions on Power Delivery, 2009

This paper presents a conceptual approach for eliminating the multiple estimation problem of impe... more This paper presents a conceptual approach for eliminating the multiple estimation problem of impedance-based fault location methods applied to power distribution systems, using the available measurements of current and voltage fundamentals at the power substation. Three test systems are used to identify the faulted lateral obtaining high performance, even in the case of similar feeder configurations. This approach shows that it is possible to obtain a unique fault location, eliminating the problem of multiple estimation in tree-shaped radial systems using the single-end measurements at the distribution substation. Finally, this approach also contributes to improve the power continuity indexes in distribution systems by the opportune zone fault location.

Research paper thumbnail of Fault Location System for Active Distribution Networks

2019 IEEE PES Innovative Smart Grid Technologies Conference - Latin America (ISGT Latin America)

Fault location performs a fundamental role in supervision and management of Active Distribution N... more Fault location performs a fundamental role in supervision and management of Active Distribution Networks. This paper presents a fault location system for active distribution networks. The system integrates fault location techniques such as impedance-based and learning based, allowing finding the exact point where the fault occurred and eliminate problems as multiples estimation. The fault location system is structured as two operation modes. In the first mode, the configuration and validation of the fault location techniques are made. In the second mode, the fault is localized using the fault Common Format for Data Transient Exchange for Power Systems file and their location on network is visualized using a geographic information system. This structure allows good adaptation of this tool to any distribution network. Simulations on the IEEE 34-nodes test feeder are presented to show the main advantages of the propose and its potential applications for real-life.

Research paper thumbnail of 1 Strategy for improvement the performance of a fault locator based on support vector machines

This paper presents a strategy aimed to improve the performance of a fault locator based on suppo... more This paper presents a strategy aimed to improve the performance of a fault locator based on support vector machines (SVM). The strategy is based on the definition of the best number of operative conditions for parameterization and training stages, oriented to reach the better performance in minimal time intervals. The proposed methodology is tested in three distribution power systems designed according to the national technical standards for the different voltage levels. This paper shows the dependence relation between the training and parameterization databases with the performance of the fault locator

Research paper thumbnail of An Adaptive Approach for Dynamic Load Modeling in Microgrids

IEEE Transactions on Smart Grid

Electric microgrids require accurate dynamic models for operation, control, stability, and protec... more Electric microgrids require accurate dynamic models for operation, control, stability, and protection studies, then adequate load modeling plays an important role. This paper presents a two-stage adaptive approach to improve the generalization capability of load models obtained with the measurement-based modeling. The load model and their respective parameters are obtained through machine learning tools like decision trees (DTs) and optimization algorithms as ant colony (ACO). In the off-line stage of the proposed approach, several parameterized load models are optimally obtained using a database of microgrid disturbances. Then, the best model to represent each disturbance is defined using a similarity criterion. This model and the disturbance characteristics are integrated into a DT (classifier), while the characteristics and the model parameters are related in a second DT (predictor). These DTs are used in an on-line stage to swiftly determine the adequate parameterized load model in the case of a new disturbance in the microgrid. The approach’s performance is compared with the conventional measurement-based load modeling in a modified CIGRE benchmark low voltage microgrid. The results evidence the advantages of the proposed adaptive approach for dynamic load modeling.

Research paper thumbnail of Hybrid methodology based on knn regression and boosting classification techniques for locating faults in distribution systems

This paper presents a hybrid methodology for fault location in power distribution systems, by usi... more This paper presents a hybrid methodology for fault location in power distribution systems, by using a regression technique based on k nearest neighbors and a classification technique which uses multiple simple classifiers in a Boosting strategy. The proposed methodology first subdivides the power system into zones to train the classification technique. Then the parameters of the regression technique are adjusted and the classification technique is trained. Finally, for an unknown case, the regression technique estimates the fault distance, and the classification technique locates the fault in one of the predefined zones, solving the multiple estimation problem. The IEEE34 node test feeder is used to test the proposed fault locator, where a good performance is obtained either in the classification task (minimal precision of 95.7 %) and the regression task (highest absolute error of 8.05%). The proposed method can be easily implemented in a power system, is fast and has low computatio...

Research paper thumbnail of Estrategia generalizada para la implementación del método de localización de fallas basado en la reactancia mínima de falla en sistemas de distribución reales

Revista Ingenieria E Investigacion, 2011

Research paper thumbnail of A power system modeling and a forward sweep- based proposal for fault location in power distribution systems

 Abstract— All of the recently proposed fault location approaches for power distribution systems... more  Abstract— All of the recently proposed fault location approaches for power distribution systems require prior knowledge of system variables at the faulted section. This is a problem in power distribution systems because these usually have measurements of voltages and currents only at the main substation. As a consequence, this document proposes a power system modeling and a forward sweep-based method aimed to estimate the values of voltage and current at the faulted section, using the power system parameters, topology and the measurements at the substation. By applying the new approach here proposed, the distance estimation error is reduced in nearly 1% from the original value. It helps to develop more precise methods for locating faults in power distribution systems, contributing in this way to improve the supply continuity and as a consequence the power quality.

Research paper thumbnail of Fault Location in Radial Power Systems Based on Statistical Analysis

Proceedings of the 10th International Conference on Probablistic Methods Applied to Power Systems, 2008

Due to the regulatory requirements related to power quality, the problem of fault location in ele... more Due to the regulatory requirements related to power quality, the problem of fault location in electrical power systems has been consider as very important, specially in power distribution utilities. In this paper, a statistical classification algorithm based on fuzzy probability functions used to locate single phase faults in distribution systems is presented. The proposed algorithm is tested in a real power distribution system, having obtained average errors of 3.53% in faulted zone identification. An application example illustrates the precision, to locate the faulted zone, obtained with the proposed methodology. The proposal provides appropriate information for the prevention and opportune attention of faults, requires minimum investment and overcomes the multiple-estimation problem of the classic impedance based methods.

Research paper thumbnail of An approach to evaluate modern fault location methods for power distribution systems

This paper presents an approach to assess automatic fault location methods in power distribution ... more This paper presents an approach to assess automatic fault location methods in power distribution systems. The proposed approach allows to consider the aleatory errors inherent to calculated, forecasted and measured values, typically required by the fault location methods for a more realistic and consistent evaluation. These errors can follow different mathematical distributions, according their source and the assumptions made. In order to demonstrate the proposed approach, a real power distribution system is considered, and additionally, one method that requires measurements at the power substation and one method that requires sparse voltage measurements are assessed.

Research paper thumbnail of An optimization-based approach for load modelling dependent voltage stability analysis

Electric Power Systems Research

Abstract A voltage stability index that considers voltage dependent load models is proposed in th... more Abstract A voltage stability index that considers voltage dependent load models is proposed in this paper for the detection of critical buses. The proposed index uses sensitivities provided from the solution of the maximum loadability problem based on an optimization model, to evaluate the voltage stability condition of power system under stress conditions caused by bus loading. The proposed index provides an accurate indication of voltage stability, by considering the difference between the maximum power transfer point and maximum loadability point using voltage dependent loads such as ZIP and exponential models. Validation tests carried out in a two-bus and the IEEE 30-bus test systems show an adequate response of the proposed approach. In first power system, the proposed index is compared to other indices and methods for voltage stability analysis, including L-index and modal analysis. Finally in the last power system, the proposed index is additional compared the extended L-index GEM.

Research paper thumbnail of A measurement-based load modelling methodology for electric vehicle fast-charging stations

Electric Power Systems Research

Abstract In this paper, a methodology to estimate the load model for electric vehicle fast-chargi... more Abstract In this paper, a methodology to estimate the load model for electric vehicle fast-charging station (EVFCS) considering a measurement-based load modelling approach, is presented. Measurements of current and active power are obtained from an EVFCS connected to IEEE-13 bus test system, considering different operating conditions. These measurements are used to adjust the load model, minimizing the mismatch between the real load and the model responses. Additionally, to demonstrate the generalization capability of the obtained load model, the cross-validation strategy is applied. According to the results, the high performance of the obtained EVFCS model makes it useful for power system studies.

Research paper thumbnail of Una propuesta de clasificación para los índices de estabilidad de tensión

INGENIERÍA Y COMPETITIVIDAD

En este artículo se presenta una revisión de las principales metodologías utilizadas para obtener... more En este artículo se presenta una revisión de las principales metodologías utilizadas para obtener índices de estabilidad de tensión en sistemas eléctricos de potencia. A partir de las clasificaciones propuestas en varias publicaciones, los autores proponen una descripción completa, mediante la inclusión de subcategorías que permiten una determinación rápida de las ventajas y deficiencias de cada propuesta. Como estrategia de presentación de la investigación, se realiza la descripción y clasificación en orden cronológico de algunas de las metodologías más relevantes en el período (1986 – 2012), utilizadas para la obtención de índices de estabilidad de tensión, considerando la información que se requiere para su implementación como criterio de clasificación. Adicionalmente, se realiza un análisis y discusión acerca de la evolución de los índices a partir de la utilización de los sistemas de medición. Finalmente, se presenta un análisis comparativo de las diferentes propuestas de imple...

Research paper thumbnail of Robustness of a generalized impedance based fault locator considering distorted measurements

Electric Power Systems Research

Abstract Power quality is a relevant aspect in power distribution systems, which among others, co... more Abstract Power quality is a relevant aspect in power distribution systems, which among others, considers service continuity and distortion of the current and voltage waveforms. This paper proposes a generalized application strategy of an impedance-based fault location method for power distribution systems and also analyses the effects of the waveform distortion on its performance, by comparing the location errors in the case of distorted and not distorted measurements of voltages and currents. Different sources of waveform distortion, such as transformer saturation, low resolution of the measuring devices, harmonics, low sampling frequency, signal noise and DC offset are analysed. According to the obtained results, the worst performance of the fault location method is obtained in the case of distortions caused by current transformer saturation. An additional circumstance of reduced performance is in such cases of simultaneous presence of low sampling rate and high harmonic distortion. Finally, the analysed values of resolution, signal noise, presence of DC offset and potential transformer saturation, cause a negligible reduction on the locator performance.

Research paper thumbnail of Application of Distance Protection on Active Distribution Networks: A Quantitative Comparison

Research paper thumbnail of Implementation analysis for grid-forming converter considering primary energy source effect

Research paper thumbnail of Clustering Techniques Performance for the Coordination of Adaptive Overcurrent Protections

Research paper thumbnail of Automatic Load Model Selection Based on Machine Learning Algorithms

IEEE Access

Technology development and decentralized operations create changes in conventional electric syste... more Technology development and decentralized operations create changes in conventional electric systems, where load modeling has been a challenge in dynamic analysis. Consequently, accurate dynamic load models are required to ensure the quality of the studies in current systems. This paper presents an automatic strategy based on clustering, classification, and optimization algorithms, to obtain the load models in the case of several system operating conditions. The obtained load models are helpful for the planning, operation, and protection of electric power systems. The proposed approach validation is performed using the IEEE 14-bus test system, where high performance is obtained. The average obtained cross-validation error for the load models assigned to the 13 clusters of disturbances is 5.36 × 10 −3. The cross-validation error is used as a tolerance value to determine when an online assigned load model is suitable to represent the measured disturbance. The proposed tests show the strategy's capabilities of defining the load model online, making this approach suitable for field applications. INDEX TERMS Dynamic load modeling, generalization capability, machine learning, parameter identification.

Research paper thumbnail of Performance analysis of a learning structured fault locator for distribution systems in the case of polluted inputs

Electric Power Systems Research, 2019

Waveform distortion and the service continuity are the two main aspects which define the power qu... more Waveform distortion and the service continuity are the two main aspects which define the power quality; in the last, the fault location plays a fundamental role. Considering the requirement of reliable tools to improve the distribution system operation, this document analyses the confidence of a fault locator approach. This paper initially presents the adjusting and the validation methodology used to develop a fault locator, and also its performance is analysed by considering different distorted measurements as inputs. The approach here presented is a learning based fault locator (LBFL), specially customized for distribution systems, whose core are the Support Vector Machines (SVM). The LBFL is tested in an unbalanced 34.5 kV distribution feeder considering diverse operating conditions and fault scenarios, which include several fault resistances, locations, and common disturbances on the voltage and current input signals. From the tests, the lowest LBFL performance is 96.5% in such cases of not distorted measurements of voltage and current. In the case of considering polluted inputs, the worse performance is obtained in the case of distortions caused by low sampling frequency, current transformer saturation and high harmonic distortion.

Research paper thumbnail of Fault Location in Power Distribution Systems Using a Learning Algorithm for Multivariable Data Analysis

IEEE Transactions on Power Delivery, 2007

This paper proposes alternatives to improve the electric power service continuity using the learn... more This paper proposes alternatives to improve the electric power service continuity using the learning algorithm for multivariable data analysis (LAMDA) classification technique to locate faults in power distribution systems. In this paper, the current and voltage waveforms measured during fault events are characterized to obtain a set of descriptors. These sets are analyzed by using the projection pursuit exploratory data

Research paper thumbnail of Data-driven topology detector for self-healing strategies in Active Distribution Networks

Research paper thumbnail of Elimination of Multiple Estimation for Fault Location in Radial Power Systems by Using Fundamental Single-End Measurements

IEEE Transactions on Power Delivery, 2009

This paper presents a conceptual approach for eliminating the multiple estimation problem of impe... more This paper presents a conceptual approach for eliminating the multiple estimation problem of impedance-based fault location methods applied to power distribution systems, using the available measurements of current and voltage fundamentals at the power substation. Three test systems are used to identify the faulted lateral obtaining high performance, even in the case of similar feeder configurations. This approach shows that it is possible to obtain a unique fault location, eliminating the problem of multiple estimation in tree-shaped radial systems using the single-end measurements at the distribution substation. Finally, this approach also contributes to improve the power continuity indexes in distribution systems by the opportune zone fault location.

Research paper thumbnail of Fault Location System for Active Distribution Networks

2019 IEEE PES Innovative Smart Grid Technologies Conference - Latin America (ISGT Latin America)

Fault location performs a fundamental role in supervision and management of Active Distribution N... more Fault location performs a fundamental role in supervision and management of Active Distribution Networks. This paper presents a fault location system for active distribution networks. The system integrates fault location techniques such as impedance-based and learning based, allowing finding the exact point where the fault occurred and eliminate problems as multiples estimation. The fault location system is structured as two operation modes. In the first mode, the configuration and validation of the fault location techniques are made. In the second mode, the fault is localized using the fault Common Format for Data Transient Exchange for Power Systems file and their location on network is visualized using a geographic information system. This structure allows good adaptation of this tool to any distribution network. Simulations on the IEEE 34-nodes test feeder are presented to show the main advantages of the propose and its potential applications for real-life.

Research paper thumbnail of 1 Strategy for improvement the performance of a fault locator based on support vector machines

This paper presents a strategy aimed to improve the performance of a fault locator based on suppo... more This paper presents a strategy aimed to improve the performance of a fault locator based on support vector machines (SVM). The strategy is based on the definition of the best number of operative conditions for parameterization and training stages, oriented to reach the better performance in minimal time intervals. The proposed methodology is tested in three distribution power systems designed according to the national technical standards for the different voltage levels. This paper shows the dependence relation between the training and parameterization databases with the performance of the fault locator

Research paper thumbnail of An Adaptive Approach for Dynamic Load Modeling in Microgrids

IEEE Transactions on Smart Grid

Electric microgrids require accurate dynamic models for operation, control, stability, and protec... more Electric microgrids require accurate dynamic models for operation, control, stability, and protection studies, then adequate load modeling plays an important role. This paper presents a two-stage adaptive approach to improve the generalization capability of load models obtained with the measurement-based modeling. The load model and their respective parameters are obtained through machine learning tools like decision trees (DTs) and optimization algorithms as ant colony (ACO). In the off-line stage of the proposed approach, several parameterized load models are optimally obtained using a database of microgrid disturbances. Then, the best model to represent each disturbance is defined using a similarity criterion. This model and the disturbance characteristics are integrated into a DT (classifier), while the characteristics and the model parameters are related in a second DT (predictor). These DTs are used in an on-line stage to swiftly determine the adequate parameterized load model in the case of a new disturbance in the microgrid. The approach’s performance is compared with the conventional measurement-based load modeling in a modified CIGRE benchmark low voltage microgrid. The results evidence the advantages of the proposed adaptive approach for dynamic load modeling.

Research paper thumbnail of Hybrid methodology based on knn regression and boosting classification techniques for locating faults in distribution systems

This paper presents a hybrid methodology for fault location in power distribution systems, by usi... more This paper presents a hybrid methodology for fault location in power distribution systems, by using a regression technique based on k nearest neighbors and a classification technique which uses multiple simple classifiers in a Boosting strategy. The proposed methodology first subdivides the power system into zones to train the classification technique. Then the parameters of the regression technique are adjusted and the classification technique is trained. Finally, for an unknown case, the regression technique estimates the fault distance, and the classification technique locates the fault in one of the predefined zones, solving the multiple estimation problem. The IEEE34 node test feeder is used to test the proposed fault locator, where a good performance is obtained either in the classification task (minimal precision of 95.7 %) and the regression task (highest absolute error of 8.05%). The proposed method can be easily implemented in a power system, is fast and has low computatio...

Research paper thumbnail of Estrategia generalizada para la implementación del método de localización de fallas basado en la reactancia mínima de falla en sistemas de distribución reales

Revista Ingenieria E Investigacion, 2011

Research paper thumbnail of A power system modeling and a forward sweep- based proposal for fault location in power distribution systems

 Abstract— All of the recently proposed fault location approaches for power distribution systems... more  Abstract— All of the recently proposed fault location approaches for power distribution systems require prior knowledge of system variables at the faulted section. This is a problem in power distribution systems because these usually have measurements of voltages and currents only at the main substation. As a consequence, this document proposes a power system modeling and a forward sweep-based method aimed to estimate the values of voltage and current at the faulted section, using the power system parameters, topology and the measurements at the substation. By applying the new approach here proposed, the distance estimation error is reduced in nearly 1% from the original value. It helps to develop more precise methods for locating faults in power distribution systems, contributing in this way to improve the supply continuity and as a consequence the power quality.

Research paper thumbnail of Fault Location in Radial Power Systems Based on Statistical Analysis

Proceedings of the 10th International Conference on Probablistic Methods Applied to Power Systems, 2008

Due to the regulatory requirements related to power quality, the problem of fault location in ele... more Due to the regulatory requirements related to power quality, the problem of fault location in electrical power systems has been consider as very important, specially in power distribution utilities. In this paper, a statistical classification algorithm based on fuzzy probability functions used to locate single phase faults in distribution systems is presented. The proposed algorithm is tested in a real power distribution system, having obtained average errors of 3.53% in faulted zone identification. An application example illustrates the precision, to locate the faulted zone, obtained with the proposed methodology. The proposal provides appropriate information for the prevention and opportune attention of faults, requires minimum investment and overcomes the multiple-estimation problem of the classic impedance based methods.

Research paper thumbnail of An approach to evaluate modern fault location methods for power distribution systems

This paper presents an approach to assess automatic fault location methods in power distribution ... more This paper presents an approach to assess automatic fault location methods in power distribution systems. The proposed approach allows to consider the aleatory errors inherent to calculated, forecasted and measured values, typically required by the fault location methods for a more realistic and consistent evaluation. These errors can follow different mathematical distributions, according their source and the assumptions made. In order to demonstrate the proposed approach, a real power distribution system is considered, and additionally, one method that requires measurements at the power substation and one method that requires sparse voltage measurements are assessed.

Research paper thumbnail of An optimization-based approach for load modelling dependent voltage stability analysis

Electric Power Systems Research

Abstract A voltage stability index that considers voltage dependent load models is proposed in th... more Abstract A voltage stability index that considers voltage dependent load models is proposed in this paper for the detection of critical buses. The proposed index uses sensitivities provided from the solution of the maximum loadability problem based on an optimization model, to evaluate the voltage stability condition of power system under stress conditions caused by bus loading. The proposed index provides an accurate indication of voltage stability, by considering the difference between the maximum power transfer point and maximum loadability point using voltage dependent loads such as ZIP and exponential models. Validation tests carried out in a two-bus and the IEEE 30-bus test systems show an adequate response of the proposed approach. In first power system, the proposed index is compared to other indices and methods for voltage stability analysis, including L-index and modal analysis. Finally in the last power system, the proposed index is additional compared the extended L-index GEM.

Research paper thumbnail of A measurement-based load modelling methodology for electric vehicle fast-charging stations

Electric Power Systems Research

Abstract In this paper, a methodology to estimate the load model for electric vehicle fast-chargi... more Abstract In this paper, a methodology to estimate the load model for electric vehicle fast-charging station (EVFCS) considering a measurement-based load modelling approach, is presented. Measurements of current and active power are obtained from an EVFCS connected to IEEE-13 bus test system, considering different operating conditions. These measurements are used to adjust the load model, minimizing the mismatch between the real load and the model responses. Additionally, to demonstrate the generalization capability of the obtained load model, the cross-validation strategy is applied. According to the results, the high performance of the obtained EVFCS model makes it useful for power system studies.

Research paper thumbnail of Una propuesta de clasificación para los índices de estabilidad de tensión

INGENIERÍA Y COMPETITIVIDAD

En este artículo se presenta una revisión de las principales metodologías utilizadas para obtener... more En este artículo se presenta una revisión de las principales metodologías utilizadas para obtener índices de estabilidad de tensión en sistemas eléctricos de potencia. A partir de las clasificaciones propuestas en varias publicaciones, los autores proponen una descripción completa, mediante la inclusión de subcategorías que permiten una determinación rápida de las ventajas y deficiencias de cada propuesta. Como estrategia de presentación de la investigación, se realiza la descripción y clasificación en orden cronológico de algunas de las metodologías más relevantes en el período (1986 – 2012), utilizadas para la obtención de índices de estabilidad de tensión, considerando la información que se requiere para su implementación como criterio de clasificación. Adicionalmente, se realiza un análisis y discusión acerca de la evolución de los índices a partir de la utilización de los sistemas de medición. Finalmente, se presenta un análisis comparativo de las diferentes propuestas de imple...

Research paper thumbnail of Robustness of a generalized impedance based fault locator considering distorted measurements

Electric Power Systems Research

Abstract Power quality is a relevant aspect in power distribution systems, which among others, co... more Abstract Power quality is a relevant aspect in power distribution systems, which among others, considers service continuity and distortion of the current and voltage waveforms. This paper proposes a generalized application strategy of an impedance-based fault location method for power distribution systems and also analyses the effects of the waveform distortion on its performance, by comparing the location errors in the case of distorted and not distorted measurements of voltages and currents. Different sources of waveform distortion, such as transformer saturation, low resolution of the measuring devices, harmonics, low sampling frequency, signal noise and DC offset are analysed. According to the obtained results, the worst performance of the fault location method is obtained in the case of distortions caused by current transformer saturation. An additional circumstance of reduced performance is in such cases of simultaneous presence of low sampling rate and high harmonic distortion. Finally, the analysed values of resolution, signal noise, presence of DC offset and potential transformer saturation, cause a negligible reduction on the locator performance.

Research paper thumbnail of Complete power distribution system representation and state determination for fault location

The impedance-based approaches for fault location in power distribution systems determine a fault... more The impedance-based approaches for fault location in power distribution systems determine a faulted line section. Next, these require of the voltages and currents at one or both section line ends to exactly determine the fault location. It is a challenge because in most of the power distribution systems, measurements are only available at the main substation. This document presents a modeling proposal for the power distribution system and an easy implementation method to estimate the voltages and currents at the faulted line section, using the measurements at the main substation, the line, load, transformer parameters and other serial and shunt connected devices and the power system topology. The approach here proposed is tested using a fault locator based on superimposed components, where the distance estimation error is lower than 1.5% in all of the cases.