Digital Power Network Parameters Measurement

Exact measurement of the parameters of a power network is now possible by digital methods. The description of the proposed and realized instrument based on the digital sampling method is given. It can measure basic parameters of the three-phase power network such as rms values of voltages and currents, powers, energies, power factors and the network frequency. Questions concerning the accuracy of measurement, error sources, and error correction are also given. A method of calibration based on the frequency output is proposed and its calculation accuracy evaluated by MATLAB

Distribution automation applications of fiber optics

Motivations for interest and research in distribution automation are discussed. The communication requirements of distribution automation are examined and shown to exceed the capabilities of power line carrier, radio, and telephone systems. A fiber optic based communication system is described that is co-located with the distribution system and that could satisfy the data rate and reliability requirements. A cost comparison shows that it could be constructed at a cost that is similar to that of a power line carrier system. The requirements for fiber optic sensors for distribution automation are discussed. The design of a data link suitable for optically-powered electronic sensing is presented. Empirical results are given. A modeling technique that was used to understand the reflections of guided light from a variety of surfaces is described. An optical position-indicator design is discussed. Systems aspects of distribution automation are discussed, in particular, the lack of interface, communications, and data standards. The economics of distribution automation are examined

Development of a user-friendly, low-cost home energy monitoring and recording system

This paper reports research undertaken to develop a user-friendly home energy monitoring system which is capable of collecting, processing and displaying detailed usage data. The system allows users to monitor power usage and switch their electronic appliances remotely, using any web enabled device, including computers, phones and tablets. The system aims to raise awareness of consumer energy use by gathering data about usage habits, and displaying this information to support consumers when selecting energy tariffs or new appliances. To achieve these aims, bespoke electrical hardware, or ‘nodes’, have been designed and built to monitor power usage, switch devices on and off, and communicate via a Wi-Fi connection, with bespoke software, the ‘server’. The server hosts a webpage which allows users to see a real-time overview of how power is being used in the home as well as allowing scheduled tasks and triggered tasks (which respond to events) to be programmed. The system takes advantage of well standardised networking specifications, such as Wi-Fi and TCP, allowing access from within the home, or remotely through the internet. The server runs under Debian Linux on a Raspberry Pi computer and is written in Python, HTML and JavaScript. The server includes advanced functionality, such as device recognition which allows users to individually monitor several devices that share a single node. The openPicus Flyport is used to provide Wi-Fi connectivity and programmable logic control to nodes. The Flyport is programmed with code compiled from C

Mass-Market Receiver for Static Positioning: Tests and Statistical Analyses

Nowadays, there are several low cost GPS receivers able to provide both pseudorange and carrier phase measurements in the L1band, that allow to have good realtime performances in outdoor condition. The present paper describes a set of dedicated tests in order to evaluate the positioning accuracy in static conditions. The quality of the pseudorange and the carrier phase measurements let hope for interesting results. The use of such kind of receiver could be extended to a large number of professional applications, like engineering fields: survey, georeferencing, monitoring, cadastral mapping and cadastral road. In this work, the receivers performance is verified considering a single frequency solution trying to fix the phase ambiguity, when possible. Different solutions are defined: code, float and fix solutions. In order to solve the phase ambiguities different methods are considered. Each test performed is statistically analyzed, highlighting the effects of different factors on precision and accurac

A rocket-borne electric field meter for the middle atmosphere

The design and construction of a rocket-borne electric field meter for determining the atmosphere's electric field and the conductivity in the middle atmosphere are considered. The operating characteristics of the instrument are discussed and a proposed flight configuration is given. The testing of the prototype is described and suggestions are advanced for further improvements

Wireless mains sensor for monitoring domestic energy consumption

Abstract. Past studies have shown that awareness of energy consumption can lead to reduction in electricity usage and that real-time, per-appliance data on electricity consumption would provide greater utility and actionable information. Yet, the customers of today’s utility companies typically have to be content with data that is aggregated, delayed and difficult to access. Comprehensive real-time data would also aid in optimizing energy consumption with respect to dynamic pricing and avoiding peak consumption periods. The objective of this thesis was to design and manufacture a wireless sensor for continuous and real-time metering of the energy consumption of a household in the UBI-AMI system version 2. The resulting Mains sensor reads the total energy consumption from the kilowatt hour meter using either a galvanic or an optical connection. The individual loads of the fuses in the circuit breaker panel are measured with Hall sensors. An 8-bit microcontroller collects analog measurements, conducts 10-bit ADC and transmits the resulting digital data to the UBI-AMI system using a commercial 6LoWPAN radio module and the CoAP protocol. The data enables the differentiation of the energy consumption of integrated and built-in elements such as floor heating and sauna from the total energy consumption of the household. The Mains sensor was tested with a demonstrator that comprised of a fuse board, a kilowatt hour meter and sockets for connecting loads. The Mains sensor was found to be flawless in reading the total energy consumption from the kilowatt hour meter using a galvanic connection. The sensor was able to read 84% of fast pulses and showed 4% surplus with slow pulses if the optical connection was used. The Hall sensors had a maximum average error of 0.47% with an active power, in comparison to a commercial energy meter. These results show that the Mains sensor provides sufficiently accurate and reliable information for improving the awareness of energy consumption of a household.Langaton sähköpäätaulusensori kotitalouden energiankulutuksen seuraamiseen. Tiivistelmä. Tutkimusten mukaan tietoisuus energiankulutuksesta voi johtaa sähkön käytön vähenemiseen, ja että tosiaikainen, laitekohtainen kulutustieto olisi hyödyllisempää. Silti nykyisin sähköyhtiöiden asiakkaiden täytyy tyypillisesti tyytyä kulutustietoihin, jotka on kerätty kokonaiskulutuksesta, ovat käytettävissä viiveellä, ja joihin on vaikea päästä käsiksi. Kattava tosiaikainen informaatio myös auttaisi huippukulutuskausien välttämisessä ja energiankulutuksen optimoinnissa dynaamisen hinnoittelun suhteen. Tämän diplomityön tavoitteena oli suunnitella ja valmistaa langaton sensori kotitalouden energiankulutuksen jatkuvaan ja tosiaikaiseen mittaukseen osana UBI-AMI-järjestelmän versiota 2. Syntynyt sähköpäätaulusensori lukee kokonaisenergiankulutuksen kilowattituntimittarista joko galvaanista tai optista yhteyttä käyttäen. Yksittäiset ryhmäkohtaiset kuormat mitataan sulaketaulusta Hallin antureilla. 8-bittinen mikrokontrolleri kerää analogiset mittaukset ja muuntaa ne digitaaliseksi dataksi, joka lähetetään UBI-AMI-järjestelmälle käyttäen kaupallista 6LoWPAN-radiomoduulia ja CoAP-protokollaa. Mittausdata mahdollistaa integroitujen ja kiinteästi asennettujen sähkölaitteiden, esimerkiksi lattialämmityksen ja saunan, energiankulutuksen eriyttämisen kotitalouden kokonaiskulutuksesta. Sähköpäätaulusensorin toiminta arvioitiin testilaitteistolla, joka koostui sulaketaulusta, kilowattituntimittarista ja pistorasioista kuormien liittämistä varten. Sähköpäätaulusensorin havaittiin lukevan kokonaisenergiankulutuksen kilowattituntimittarista virheettömästi galvaanista yhteyttä käyttäen. Optista yhteyttä käytettäessä sensori kykeni lukemaan 84 % nopeista pulsseista ja hitaat pulssit saivat sensorin mittaamaan käytetyn energian 4% todellista suuremmaksi. Hallin antureilla suurin keskimääräinen virhe kaupalliseen mittariin verrattuna oli 0,47 % pätötehollisella kuormalla. Tulosten perusteella sähköpäätaulusensori antaa riittävän tarkkaa ja luotettavaa tietoa energiankulutuksesta ja sitä voidaan käyttää energiankulutuksen tietoisuuden lisäämiseen kotitalouksissa

Enhancing the efficiency of electricity utilization through home energy management systems within the smart grid framework

The concept behind smart grids is the aggregation of “intelligence” into the grid, whether through communication systems technologies that allow broadcast/data reception in real-time, or through monitoring and systems control in an autonomous way. With respect to the technological advancements, in recent years there has been a significant increment in devices and new strategies for the implementation of smart buildings/homes, due to the growing awareness of society in relation to environmental concerns and higher energy costs, so that energy efficiency improvements can provide real gains within modern society. In this perspective, the end-users are seen as active players with the ability to manage their energy resources, for example, microproduction units, domestic loads, electric vehicles and their participation in demand response events. This thesis is focused on identifying application areas where such technologies could bring benefits for their applicability, such as the case of wireless networks, considering the positive and negative points of each protocol available in the market. Moreover, this thesis provides an evaluation of dynamic prices of electricity and peak power, using as an example a system with electric vehicles and energy storage, supported by mixed-integer linear programming, within residential energy management. This thesis will also develop a power measuring prototype designed to process and determine the main electrical measurements and quantify the electrical load connected to a low voltage alternating current system. Finally, two cases studies are proposed regarding the application of model predictive control and thermal regulation for domestic applications with cooling requirements, allowing to minimize energy consumption, considering the restrictions of demand, load and acclimatization in the system

Magnetic and electric field meters developed for the US Department of Energy

This report describes work done at the Jet Propulsion Laboratory for the Office of Energy Storage and Distribution of DOE on the measurement of power line fields. A magnetic field meter is discussed that uses fiber optics to couple a small measuring probe to a remote readout device. The use of fiber optics minimizes electric field perturbation due to the presence of the probe and provides electric isolation for the probe, so that it could be used in a high field or high voltage environment. Power to operate the sensor electronics is transferred via an optical fiber, and converted to electrical form by a small photodiode array. The fundamental, the second and third harmonics of the field are filtered and separately measured, as well as the broadband rms level of the field. The design of the meter is described in detail and data from laboratory tests are presented. The report also describes work done to improve the performance of a DC bushing in a Swedish factory, using the improved meter. The DC electric fields are measured with synchronous detection to provide field magnitude data in two component directions