Accurate Classification of Partial Discharge Phenomena in Power Transformers in the Presence of Noise

The objective of this research is to accurately classify different types of Partial Discharge (PD) phenomenon that occurs in transformers in the presence of noise. A PD is an electrical discharge or spark that bridges a small portion of the insulation in electrical equipment, which causes progressive deterioration of high voltage equipment and could potentially lead to flashover. The data for the study is generated from a laboratory setup and it is 300 time series signals each with 2016 attributes corresponding to 3 types of PDs; namely: Porcelain, Cable and Corona. The data is collected from two sensors with different bandwidths, in which Channel A signals refer to the data collected from the higher frequency sensor and signals from Channel B refer to data of the lower frequency sensor. Different feature engineering approaches are investigated in order to find the set of the most discriminant features which help to achieve high levels of classification accuracy for Channel A and Channel B signals. First, features that describe the shape and pulse of signals in the time domain are extracted. Then frequency domain based statistical features are generated. In comparison with classification accuracies using frequency domain features, time domain based features gave higher accuracy of more than 90% on average for both channels in the absence of noise while frequency domain features allowed classification accuracy up to 80% on average. However, in the presence of noise, both methods degraded. To overcome this, Regularization techniques were applied on the features from the frequency domain which helped to maintain classification accuracy even in the presence of high levels of noise

IEC 61850 Sampled Value -sovellukset sähköverkoissa

Tämä kandidaatintyö on kirjallisuuskatsaus IEC 61850 -standardiin ja standardin määrittelemään Sampled Value -protokollaan sekä sen sovelluksiin sähköverkoissa. Työn tavoitteena on selventää sähköasema-automaation standardia IEC 61850 ja standardissa hyödynnettävää Sampled Value -protokollaa sekä selvittää missä sovelluksissa Sampled Value -protokollaa hyödynnetään. Työssä esitellään yleiskuva IEC 61850 -standardista ja Sampled Value -protokollasta, joita hyödynnetään sähköverkon sovelluksissa. Lisäksi työssä tarkastellaan millaisissa sovelluksissa ja miten Sampled Value -protokollaa hyödynnetään. IEC 61850 -standardi on sähköasema-automaatioon kehitetty globaali standardi, joka on myöhemmin laajentunut muihin sähköverkon osiin. IEC 61850 -standardi määrittelee sähkövoimajärjestelmän erilaiset kommunikaatiotavat automatisointiin, suojaukseen ja hallintaan. Sampled Value -protokollalla pystytään siirtämään digitaalista mittausdataa Ethernet-pohjaisen tiedonsiirtoväylän avulla. Sampled Value -viestien avulla saadaan välitettyä lähes reaaliaikasta dataa sähkövoimajärjestelmän tilasta. Yleisimmät komponentit, jotka hyödyntävät Sampled Value -protokollaa ovat älykkäät elektroniset laitteet, Merging Unit -laitteet ja digitaaliset mittalaitteet. Lisäksi Sampled Value -protokollaa voidaan hyödyntää erilaisissa sähköverkon sovelluksissa, kuten sähköauton latausjärjestelmässä osana hajautettua energiantuotantojärjestelmää. Työssä osoitetaan, että Sampled Value -protokollaa pystytään hyödyntämään hyvin laajasti sähköverkoissa. Protokollan avulla saavutetaan merkittäviä hyötyjä, kuten edullisemmat sähkövoimajärjestelmän rakennus- ja käyttökustannukset sekä nopeampi tiedonsiirto järjestelmän sisällä. IEC 61850 -standardissa määritelty Sampled Value -protokollan käyttötapa ei kuitenkaan ole täysin yksikäsitteinen, jonka takia laitteiden välinen yhteensopivuus saattaa hankaloitua

Automatic fault location in electrical distribution networks with distributed generation

Nowadays the electrical network is continuously evolving due to the increasing deployment of Information Technologies and the Distribution Energy Resources. This scenario affects directly to the quality of service in the electrical distribution networks. For this reason, the Power Quality is a key important concern to make the electrical network evolve towards a Smart Grid. Power quality is defined through three important focal points: availability, wave quality and commercial quality. The presence of the Distribution Energy Resources in the current electrical distribution network is showing a new scenario where the fault detection is more complex due to the flow current is in both directions. This thesis is focused in the analysis of several methods to locate a fault in electrical distribution network and also how the current communication standards can improve considerably this fault location. It is important to remark that the main contribution of this thesis is in the analysis of several propositions and algorithms to enhance the fault location in a distribution network using the current Intelligent Electronic Device with international standards such as IEC 61850. All of these algorithms have been focused to work in a mesh distribution networks. Another important contribution of this thesis is in the adaptive protection system in order to isolate correctly the fault in a ring system distribution. Although this proposition could be extended to a mesh network where the elements of the network can operate under a fault. Finally, the thesis concludes that the use of communication standards and Internet of Things with current developed Intelligent Electronic Devices technology can contribute significantly to enhance the current and future electrical network distribution.La xarxa elèctrica evoluciona contínuament a causa del creixent desplegament de les Tecnologies de la Informació i dels Recursos Energètics Distribuïts. Aquest escenari afecta directament a la qualitat de servei de les xarxes de distribució elèctrica. Per aquest motiu, el mantenir i millorar el nivell de qualitat d'energia és un punt clau per fer evolucionar la xarxa elèctrica cap a una xarxa Smart Grid. Aquesta qualitat de l'energia es defineix per medi de de tres punts importants: disponibilitat, qualitat d'ona i qualitat comercial. La presència dels Recursos Energètics Distribuïts mostra un nou escenari en què la detecció de defectes es complica afectant a la disponibilitat del servei. Aquesta tesi es centra principalment en l'anàlisi de diversos mètodes per localitzar un defecte a la xarxa de distribució elèctrica i també en com l'ús dels estàndards de comunicació actuals poden contribuir considerablement a la localització del defecte. És important remarcar que la principal contribució d'aquest document ha estat en l'anàlisi de diverses proposicions i algoritmes per millorar la localització de faltes en una xarxa de distribució utilitzant Dispositius Electrònics Intel·ligents amb estàndards internacionals com l'IEC 61850. Tots aquests algoritmes han estat definits per treballar en xarxes de distribució mallades. Una altra contribució important d'aquesta tesi es troba en el sistema de protecció adaptatiu per tal d'aïllar correctament el defecte en una distribució del sistema d'anell amb interruptors automàtics. Aquesta proposta es podria ampliar a una xarxa mallada. Finalment, la tesi conclou amb que l'ús d'estàndards de comunicació i l'Internet of Things en combinació amb Dispositius Electrònics Intel·ligents, desenvolupats actualment, poden contribuir significativament a millorar la distribució de la xarxa elèctrica actual i futura.Postprint (published version

Automatic fault location in electrical distribution networks with distributed generation

Nowadays the electrical network is continuously evolving due to the increasing deployment of Information Technologies and the Distribution Energy Resources. This scenario affects directly to the quality of service in the electrical distribution networks. For this reason, the Power Quality is a key important concern to make the electrical network evolve towards a Smart Grid. Power quality is defined through three important focal points: availability, wave quality and commercial quality. The presence of the Distribution Energy Resources in the current electrical distribution network is showing a new scenario where the fault detection is more complex due to the flow current is in both directions. This thesis is focused in the analysis of several methods to locate a fault in electrical distribution network and also how the current communication standards can improve considerably this fault location. It is important to remark that the main contribution of this thesis is in the analysis of several propositions and algorithms to enhance the fault location in a distribution network using the current Intelligent Electronic Device with international standards such as IEC 61850. All of these algorithms have been focused to work in a mesh distribution networks. Another important contribution of this thesis is in the adaptive protection system in order to isolate correctly the fault in a ring system distribution. Although this proposition could be extended to a mesh network where the elements of the network can operate under a fault. Finally, the thesis concludes that the use of communication standards and Internet of Things with current developed Intelligent Electronic Devices technology can contribute significantly to enhance the current and future electrical network distribution.La xarxa elèctrica evoluciona contínuament a causa del creixent desplegament de les Tecnologies de la Informació i dels Recursos Energètics Distribuïts. Aquest escenari afecta directament a la qualitat de servei de les xarxes de distribució elèctrica. Per aquest motiu, el mantenir i millorar el nivell de qualitat d'energia és un punt clau per fer evolucionar la xarxa elèctrica cap a una xarxa Smart Grid. Aquesta qualitat de l'energia es defineix per medi de de tres punts importants: disponibilitat, qualitat d'ona i qualitat comercial. La presència dels Recursos Energètics Distribuïts mostra un nou escenari en què la detecció de defectes es complica afectant a la disponibilitat del servei. Aquesta tesi es centra principalment en l'anàlisi de diversos mètodes per localitzar un defecte a la xarxa de distribució elèctrica i també en com l'ús dels estàndards de comunicació actuals poden contribuir considerablement a la localització del defecte. És important remarcar que la principal contribució d'aquest document ha estat en l'anàlisi de diverses proposicions i algoritmes per millorar la localització de faltes en una xarxa de distribució utilitzant Dispositius Electrònics Intel·ligents amb estàndards internacionals com l'IEC 61850. Tots aquests algoritmes han estat definits per treballar en xarxes de distribució mallades. Una altra contribució important d'aquesta tesi es troba en el sistema de protecció adaptatiu per tal d'aïllar correctament el defecte en una distribució del sistema d'anell amb interruptors automàtics. Aquesta proposta es podria ampliar a una xarxa mallada. Finalment, la tesi conclou amb que l'ús d'estàndards de comunicació i l'Internet of Things en combinació amb Dispositius Electrònics Intel·ligents, desenvolupats actualment, poden contribuir significativament a millorar la distribució de la xarxa elèctrica actual i futura

Desenvolvimento e Implementação de um sistema de monitoramento de qualidade de energia para tomada de decisões em sistemas de transmissão

The growing penetration of large blocks of renewable energy based on electronic inverters in power transmission systems can decrease the power quality of these systems, especially with increasing harmonic and interharmonic distortion and voltage fluctuation. Poor electrical power quality (PQ) can negatively affect the protection system and can cause premature aging of electrical equipment connected to the power system. Thus, continuous monitoring of the PQ and in real time can be of great value for the operation, maintenance and expansion of the power systems. This dissertation presents the real-time PQ monitoring system recently implemented in two transmission substations of the company TBE (Transmissoras Brasileiras de Energia) as part of the Aneel R&D project “Development of a monitoring system for power quality and decision-making in transmission lines” and which involved the participation of several researchers from UFJF, UNIFEI and UFSC. The monitoring system is based on the philosophy of Digitally Enabled Substation Architecture or Substation 4.0 (SB4.0). SB4.0 involves concepts of open architecture, vendor independence, interoperability, and scalability. The system developed for monitoring the PQ receives samples of voltage and current signals from a Merging Unit (MU) through the IEC 61850-9-2 (SV) protocol and calculates the various power quality parameters. As the system uses the SB4.0 concept, power quality monitoring is a software application implemented on an industrial computer. In addition, the system provides a Data Recording application, which runs as an additional software task that provides instantaneous Total Harmonic Distortion (iTHD) triggered oscillography. This dissertation presents the main aspects of the architecture of the system developed and implemented, as well as the field results obtained from the two monitored substations.O crescimento da penetração de grandes blocos de energia renovável baseada em inversores eletrônicos em sistemas de transmissão de energia pode diminuir a qualidade de energia desses sistemas, especialmente com o aumento da distorção harmônica e inter harmônica e flutuação de tensão. A má qualidade de energia elétrica (QEE) pode afetar negativamente o sistema de proteção e pode causar envelhecimento prematuro do equipamento elétrico conectado ao sistema de energia. Assim, o monitoramento contínuo da QEE e em tempo real pode ser de grande valor para a operação, manutenção e expansão do sistema. Esta dissertação apresenta o sistema de monitoramento de QEE em tempo real implementado recentemente em duas subestações de transmissão da empresa TBE (Transmissoras Brasileiras de Energia) como parte do projeto P&D Aneel “Desenvolvimento de um sistema de monitoramento de qualidade de energia e tomada de decisões em linhas de transmissão” e que envolveu a participação de diversos pesquisadores da UFJF, UNIFEI e UFSC. O sistema de monitoramento é baseado na filosofia de Arquitetura de Subestação habilitada digitalmente ou Subestação 4.0 (SB4.0). A SB4.0 envolve conceitos de arquitetura aberta, independência de fabricante, interoperabilidade escalabilidade. O sistema desenvolvido para o monitoramento da QEE recebe amostras de sinais de tensão e corrente de uma Merging Unit (MU) através do protocolo IEC 61850-9-2 (SV) e calcula os vários parâmetros de qualidade de energia. Como o sistema usa o conceito SB4.0, o monitoramento da qualidade de energia é um aplicativo de software implementado em um computador industrial. Além disso, o sistema fornece um aplicativo de Gravação de Dados, executado como tarefa de software adicional que fornece oscilografia acionada por Distorção Harmônica Total instantânea (iTHD). Esta dissertação apresenta os principais aspectos da arquitetura do sistema desenvolvido e implementado, bem como os resultados de campo obtidos das duas subestações monitoradas

Development of the future generation of smart high voltage connectors and related components for substations, with energy autonomy and wireless data transmission capability

The increased dependency on electricity of modern society, makes reliability of power transmission systems a key point. This goal can be achieved by continuously monitoring power grid parameters, so possible failure modes can be predicted beforehand. It can be done using existing Information and Communication Technologies (ICT) and Internet of Things (10T) technologies that include instrumentation and wireless communication systems, thus forming a wireless sensor network (WSN). Electrical connectors are among the most critical parts of any electrical system and hence, they can act as nodes of such WSN. Therefore, the fundamental objective of this thesis is the design, development and experimental validation of a self-powered IOT solution for real-time monitoring of the health status of a high-voltage substation connector and related components of the electrical substation. This new family of power connectors is called SmartConnector and incorporates a thermal energy harvesting system powering a microcontroller that controls a transmitter and several electronic sensors to measure the temperature, current and the electrical contact resistance (ECR) of the connector. These measurements are sent remotely via a Bluetooth 5 wireless communication module to a local gateway, which further transfers the measured data to a database server for storage as well as further analysis and visualization. By this way, after suitable data processing, the health status of the connector can be available in real-time, allowing different appealing functions, such as assessing the correct installation of the connector, the current health status or its remaining useful life (RUL) in real-time. The same principal can also be used for other components of substation like spacers, insulators, conductors, etc. Hence, to prove universality of this novel approach, a similar strategy is applied to a spacer which is capable of measuring uneven current distribution in three closely placed conductors. This novel IOT device is called as SmartSpacer. Care has to be taken that this technical and scientific development has to be compatible with existing substation bus bars and conductors, and especially to be compatible with the high operating voltages, i.e., from tens to hundreds of kilo-Volts (kV), and with currents in the order of some kilo-pm peres (kA). Although some electrical utilities and manufacturers have progressed in the development of such technologies, including smart meters and smart sensors, electrical device manufacturers such as of substation connectors manufacturers have not yet undertaken the technological advancement required for the development of such a new family of smart components involved in power transmission, which are designed to meet the future needs.La mayor dependencia de la electricidad de la sociedad moderna hace que la fiabilidad de los sistemas de transmisión de energía sea un punto clave. Este objetivo se puede lograr mediante la supervisión continua de los parámetros de la red eléctrica, por lo que los posibles modos de fallo se pueden predecir de antemano. Se puede hacer utilizando las tecnologías existentes de Tecnologías de la Información y la Comunicación (1CT) e Internet de las cosas (lo T) que incluyen sistemas de instrumentación y comunicación inalámbrica, formando así una red de sensores inalámbricos (WSN). Los conectores eléctricos se encuentran entre las partes más críticas de cualquier sistema eléctrico y, por lo tanto, pueden actuar como nodos de dicho VVSN. Por lo tanto, el objetivo fundamental de esta tesis es el diseño, desarrollo y validación experimental de una solución IOT autoalimentada para la supervisión en tiempo real del estado de salud de un conector de subestación de alta tensión y componentes relacionados de la subestación eléctrica. Esta nueva familia de conectores de alimentación se llama SmartConnector e incorpora un sistema de recolección de energía térmica que alimenta un microcontrolador que controla un transmisor y varios sensores electrónicos para medir la temperatura, la corriente y la resistencia del contacto eléctrico (ECR) del conector. Esta nueva familia de conectores de alimentación se llama SmartConnector e incorpora un sistema de recolección de energía térmica que alimenta un microcontrolador que controla un transmisor y varios sensores electrónicos para medir la temperatura, la corriente y la resistencia al contacto eléctrico (ECR) del conector. De esta manera, después del procesamiento de datos adecuado, el estado de salud del conector puede estar disponible en tiempo real, permitiendo diferentes funciones atractivas, como evaluar la correcta instalación del conector, el estado de salud actual o su vida útil restante (RUL) en tiempo real. El mismo principio también se puede utilizar para otros componentes de la subestación como espaciadores, aislantes, conductores, etc. Por lo tanto, para demostrar la universalidad de este enfoque novedoso, se aplica una estrategia similar a un espaciador, que es capaz de medir la distribución de corriente desigual en tres conductores estrechamente situados. Hay que tener cuidado de que este desarrollo técnico y científico tenga que sea compatible con las barras y "busbars" de subestación existentes, y sobre todo para ser compatible con las altas tensiones de funcionamiento, es decir, de decenas a cientos de kilovoltios (kV), y con corrientes en el orden de algunos kilo-Amperes (kA). Aunque algunas empresas eléctricas y fabricantes han progresado en el desarrollo de este tipo de tecnologías, incluidos medidores inteligentes y sensores inteligentes, los fabricantes de dispositivos eléctricos, como los fabricantes de conectores de subestación, aún no han emprendido el avance tecnológico necesario para el desarrollo de una nueva familia de componentes intel

Engineering and built environment project conference 2014: book of abstracts - Toowoomba, Australia, 22-26 September 2014

Book of Abstracts of the USQ Engineering and Built Environment Conference 2014, held Toowoomba, Australia, 22-26 September 2014. These proceedings include extended abstracts of the verbal presentations that are delivered at the project conference. The work reported at the conference is the research undertaken by students in meeting the requirements of courses ENG4111/ENG4112 Research Project for undergraduate or ENG8411/ENG8412 Research Project and Dissertation for postgraduate students

Undergraduate engineering and built environment project conference 2017: book of abstracts - Toowoomba, Australia, 18-22 September 2017

Book of Abstracts of the USQ Undergraduate Engineering and Built Environment Conference 2017, held Toowoomba, Australia, 18-22 September 2017. These proceedings include extended abstracts of the verbal presentations that are delivered at the project conference. The work reported at the conference is the research undertaken by students in meeting the requirements of courses ENG4111/ENG4112 Research Project

Event and Intrusion Detection Systems for Cyber-Physical Power Systems

High speed data from Wide Area Measurement Systems (WAMS) with Phasor Measurement Units (PMU) enables real and non-real time monitoring and control of power systems. The information and communication infrastructure used in WAMS efficiently transports information but introduces cyber security vulnerabilities. Adversaries may exploit such vulnerabilities to create cyber-attacks against the electric power grid. Control centers need to be updated to be resilient not only to well-known power system contingencies but also to cyber-attacks. Therefore, a combined event and intrusion detection systems (EIDS) is required that can provide precise classification for optimal response. This dissertation describes a WAMS cyber-physical power system test bed that was developed to generate datasets and perform cyber-physical power system research related to cyber-physical system vulnerabilities, cyber-attack impact studies, and machine learning algorithms for EIDS. The test bed integrates WAMS components with a Real Time Digital Simulator (RTDS) with hardware in the loop (HIL) and includes various sized power systems with a wide variety of implemented power system and cyber-attack scenarios. This work developed a novel data processing and compression method to address the WAMS big data problem. The State Tracking and Extraction Method (STEM) tracks system states from measurements and creates a compressed sequence of states for each observed scenario. Experiments showed STEM reduces data size significantly without losing key event information in the dataset that is useful to train EIDS and classify events. Two EIDS are proposed and evaluated in this dissertation. Non-Nested Generalized Exemplars (NNGE) is a rule based classifier that creates rules in the form of hyperrectangles to classify events. NNGE uses rule generalization to create a model that has high accuracy and fast classification time. Hoeffding adaptive trees (HAT) is a decision tree classifier and uses incremental learning which is suitable for data stream mining. HAT creates decision trees on the fly from limited number of instances, uses low memory, has fast evaluation time, and adapts to concept changes. The experiments showed NNGE and HAT with STEM make effective EIDS that have high classification accuracy, low false positives, low memory usage, and fast classification times

Event and Intrusion Detection Systems for Cyber-Physical Power Systems

High speed data from Wide Area Measurement Systems (WAMS) with Phasor Measurement Units (PMU) enables real and non-real time monitoring and control of power systems. The information and communication infrastructure used in WAMS efficiently transports information but introduces cyber security vulnerabilities. Adversaries may exploit such vulnerabilities to create cyber-attacks against the electric power grid. Control centers need to be updated to be resilient not only to well-known power system contingencies but also to cyber-attacks. Therefore, a combined event and intrusion detection systems (EIDS) is required that can provide precise classification for optimal response. This dissertation describes a WAMS cyber-physical power system test bed that was developed to generate datasets and perform cyber-physical power system research related to cyber-physical system vulnerabilities, cyber-attack impact studies, and machine learning algorithms for EIDS. The test bed integrates WAMS components with a Real Time Digital Simulator (RTDS) with hardware in the loop (HIL) and includes various sized power systems with a wide variety of implemented power system and cyber-attack scenarios. This work developed a novel data processing and compression method to address the WAMS big data problem. The State Tracking and Extraction Method (STEM) tracks system states from measurements and creates a compressed sequence of states for each observed scenario. Experiments showed STEM reduces data size significantly without losing key event information in the dataset that is useful to train EIDS and classify events. Two EIDS are proposed and evaluated in this dissertation. Non-Nested Generalized Exemplars (NNGE) is a rule based classifier that creates rules in the form of hyperrectangles to classify events. NNGE uses rule generalization to create a model that has high accuracy and fast classification time. Hoeffding adaptive trees (HAT) is a decision tree classifier and uses incremental learning which is suitable for data stream mining. HAT creates decision trees on the fly from limited number of instances, uses low memory, has fast evaluation time, and adapts to concept changes. The experiments showed NNGE and HAT with STEM make effective EIDS that have high classification accuracy, low false positives, low memory usage, and fast classification times