310 research outputs found
A frequency-based RF partial discharge detector for low-power wireless sensing
Partial discharge (PD) monitoring has been the subject of significant research in recent years, which has given rise to a range of well-established PD detection and measurement techniques, such as acoustic and RF, on which condition monitoring systems for highvoltage equipment have been based. This paper presents a novel approach to partial discharge monitoring by using a low-cost, low-power RF detector. The detector employs a frequency-based technique that can distinguish between multiple partial discharge events and other impulsive noise sources within a substation, tracking defect severity over time and providing information pertaining to plant health. The detector is designed to operate as part of a wireless condition monitoring network, removing the need for additional wiring to be installed into substations whilst still gaining the benefits of the RF technique. This novel approach to PD detection not only provides a low-cost solution to on-line partial discharge monitoring, but also presents a means to deploy wide-scale RF monitoring without the associated costs of wide-band monitoring systems
An Overview of Broadband communication over Power Lines
Broadband over power lines are Systems for carrying
data on conductors used for electric power
transmission. Power line communication technologies
can be used for different applications ranging from
home automation to internet access.
With the spread of broadband technologies in the last
few years, there are yet significant areas in the world
that do not have access to high speed internet, as
compared with the few internet service providers in
existence, the additive expenditures of laying cables
and building necessary infrastructure to provide DSL
in many areas most especially rural areas is too great.
But if broadband is served through power lines
considering the fact that it exist all over the country,
there will be no need to build new infrastructure.
Therefore, anywhere there is electricity, there could
also be broadband.
Broadband over Power line is designed to offer an
alternative means to provide high speed internet
access, voice over Internet protocol (VOIP) and other
broadband services, using medium and low voltage
lines to reach customers and businesses by combining
the principle of wireless networking, modems and
Radio. Researchers and developers have created ways
to transmit data over power lines into homes at
speeds between 500kilobits and 3 megabits per
second which is equivalent to the cable DSL (Digital
Subscriber Line) and this is achieved by modifying
the present power grids with specialized equipments.
With this knowledge, the broadband power line
developers could partner with power companies and
Internet service providers to bring broadband to
everyone with access to electricity
Detection of super-high-frequency partial discharge by using neural networks
A system has been developed for the detection of super-high-frequency (SHF) partial discharge (PD) at frequencies up to 6 GHz. The system consists of three antennas for capturing PDs and a fast digital oscilloscope for sampling data. One of the antennas is a disk-cone antenna with frequency range below 710 MHz. The other two half TEM horn antennas have been designed and constructed for the frequency range 716 MHz - 5 GHz. To extend the frequency range up to 6 GHz, a methodology has been developed by compensating amplitude-response to frequency-magnitude. The compensation is realised by using multilayer feed-forward neural networks to equalise on amplitude-response. A direct sampling method is used to log the captured PD data. This PD detection system has been implemented to measure PDs at a 400 kV electrical substation (Strathaven, Scottish Power Ltd)
Time domain analysis of switching transient fields in high voltage substations
Switching operations of circuit breakers and disconnect switches generate transient currents propagating along the substation busbars. At the moment of switching, the busbars temporarily acts as antennae radiating transient electromagnetic fields within the substations. The radiated fields may interfere and disrupt normal operations of electronic equipment used within the substation for measurement, control and communication purposes. Hence there is the need to fully characterise the substation electromagnetic environment as early as the design stage of substation planning and operation to ensure safe operations of the electronic equipment. This paper deals with the computation of transient electromagnetic fields due to switching within a high voltage air-insulated substation (AIS) using the finite difference time domain (FDTD) metho
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 transmisiĂłn de energĂa sea un punto clave. Este objetivo se puede lograr mediante la supervisiĂłn continua de los parámetros de la red elĂ©ctrica, por lo que los posibles modos de fallo se pueden predecir de antemano. Se puede hacer utilizando las tecnologĂas existentes de TecnologĂas de la InformaciĂłn y la ComunicaciĂłn (1CT) e Internet de las cosas (lo T) que incluyen sistemas de instrumentaciĂłn y comunicaciĂłn inalámbrica, formando asĂ una red de sensores inalámbricos (WSN). Los conectores elĂ©ctricos se encuentran entre las partes más crĂticas de cualquier sistema elĂ©ctrico 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 validaciĂłn experimental de una soluciĂłn IOT autoalimentada para la supervisiĂłn en tiempo real del estado de salud de un conector de subestaciĂłn de alta tensiĂłn y componentes relacionados de la subestaciĂłn elĂ©ctrica. Esta nueva familia de conectores de alimentaciĂłn se llama SmartConnector e incorpora un sistema de recolecciĂłn de energĂa tĂ©rmica que alimenta un microcontrolador que controla un transmisor y varios sensores electrĂłnicos para medir la temperatura, la corriente y la resistencia del contacto elĂ©ctrico (ECR) del conector. Esta nueva familia de conectores de alimentaciĂłn se llama SmartConnector e incorpora un sistema de recolecciĂłn de energĂa tĂ©rmica que alimenta un microcontrolador que controla un transmisor y varios sensores electrĂłnicos para medir la temperatura, la corriente y la resistencia al contacto elĂ©ctrico (ECR) del conector. De esta manera, despuĂ©s 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 instalaciĂłn del conector, el estado de salud actual o su vida Ăştil restante (RUL) en tiempo real. El mismo principio tambiĂ©n se puede utilizar para otros componentes de la subestaciĂłn 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 distribuciĂłn de corriente desigual en tres conductores estrechamente situados. Hay que tener cuidado de que este desarrollo tĂ©cnico y cientĂfico tenga que sea compatible con las barras y "busbars" de subestaciĂłn 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 elĂ©ctricas y fabricantes han progresado en el desarrollo de este tipo de tecnologĂas, incluidos medidores inteligentes y sensores inteligentes, los fabricantes de dispositivos elĂ©ctricos, como los fabricantes de conectores de subestaciĂłn, aĂşn no han emprendido el avance tecnolĂłgico necesario para el desarrollo de una nueva familia de componentes intel
A wireless system for monitoring leakage current in electrical substation equipment
In this paper, the design and the development of a remote system for continuous monitoring of leakage currents and ground currents in high voltage electrical substations are proposed. Based on wireless local area network technology, the system can be used to monitor continuously a variety of plants within the substation and has low power consumption with inbuilt overvoltage protection. It consists of a transmitter module equipped with a data acquisition (DAQ) system connected to leakage current and voltage sensors, and a receiver module connected to a remote controller for data processing and storage. The principle of operation and the characteristics of the various components of the system are described. Validation tests have been used to verify its performance in three different test situations: A) laboratory monitoring of the leakage current and voltage of a distribution surge arrester; B) laboratory measurement of the leakage current of an outdoor insulator; and C) field monitoring of the earth current and potential rise of high-voltage tower. The measured results are in close agreement with those recorded directly through a DAQ card with fiber-optic and coaxial cable connected systems. Data processing is carried out at the receiving end so that the monitored parameter is displayed continuously or at specified time intervals. The operation of the system has been tested and proved resilient under high-frequency interference signals such as those generated by corona and surface discharges
WiMAX for Smart Grid Applications and the Influence of Impulsive Noise
In order to adapt the power grid to today’s level of electricity consumption, growing investments are made in a smart power grid. The employment of this novel architecture brings advantages such as efficiency of energy production and consumption, availability and reliability of the service, scalability, self-healing grid, environment friendly, consumer participation in electricity production with harvested energy through solar panels and wind turbines. The rising power demand curve can be restrained by a smart implementation of the new electrical power grid. The smart grid brings out an additional layer that will interconnect and manage all the generation, transmission and distribution sectors of the power grid. Many other features will be brought by the smart grid that will improve its reliability and efficiency and will lead towards renewable and sustainable energy development. In this thesis, we analyze the performances of a smart grid in which the communication layer is implemented using Worldwide Interoperability for Microwave Access (WiMAX) communication technology. Parameters such as throughput, network capacity, packet loss, latency are studied by analyzing the traffic model generated by using several applications in the Distribution Area Network (DAN) of the Smart Grid. The applications whose traffic was simulated using OPNET are the following four: metering and pricing, electrical car, video surveillance and voice support for workforce. The capacity of a base station in the distribution area network is obtained for each smart grid application individually as well as for the combined traffic of all applications. Furthermore, this thesis also discusses the effects of the impulsive noise over the communication layer. An Orthogonal Frequency Division Multiplexing (OFDM) structure using WiMAX physical layer characteristics was simulated with and without the influence of impulsive noise using MATLAB. The results highlighted the effects of the impulsive noise over performances such as bit error rate, packet error rate, throughput and the overall capacity of the network. For a better understanding, the outcomes are presented with and without the presence of impulsive noise
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