IoT-teknologian hyödyntäminen sähköverkko-omaisuuden hallinnassa

Objective of this thesis is to define and assess changes in energy sector, which will directly or indirectly affect distribution grid operation and management in Finland, and to determine measurable events or variables, which enable identification and monitoring of the recognized changes. Based on assessment of the upcoming changes, possibilities for utilizing IoT technologies in management and monitoring applications of the identified changes, are assessed. In the assessment of upcoming changes, total of eight subjects were covered and microgeneration, electric vehicles and heat pumps were identified to be the most probable changes to realistically penetrate Finnish energy sector within a time scope of approximately 10 years. However, none of the assessed, changes, were found to have significant and wide-scale effects in terms of performance of Finnish distribution networks. For utilization of IoT technologies in distribution networks one application for operational grid monitoring of power quality problems derived from residential photovoltaic generation, and three cases for IoT based asset health and condition monitoring were assessed. Furthermore, requirements and architecture for data storage and analysis platform of IoT based system were discussed. From the evaluated applications condition monitoring scheme of circuit breakers was determined to be the most promising alternative.Diplomityön tavoitteena on määritellä ja arvioida energiasektoriin vaikuttavien tulevien muutosten suoria tai epäsuoria vaikutuksia jakeluverkon toimintaan ja hallintaan. Havaittujen muutosten vaikutuksista on tarkoitus tunnistaa mitattavia ilmiöitä tai suureita, jotka mahdollistavat muutosten tunnistamisen sekä seurannan. Muutosanalyysiin pohjautuen tavoitteena on tunnistaa ja arvioida mahdollisuuksia IoT-teknologian hyödyntämiseksi havaittujen muutosten aiheuttamien ongelmakohtien tai mahdollisuuksien tunnistamisessa, seurannassa sekä hallinnassa. Energiasektoriin vaikuttavien muutosten analyysissä arvoitiin kokonaisuudessaan kahdeksaa eri aihealuetta ja lopputuloksena pientuotannon, sähköautojen sekä lämpöpumppujen todettiin olevan todennäköisimmät teknologiat, jotka yleistyvät merkittävissä määrin suomalaisessa sähköverkossa seuraavan kymmenen vuoden aikana. Minkään käsitellyn muutoskohdan ei kuitenkaan todettu aiheuttavan laajamittaisia ja merkittäviä ongelmia jakeluverkon toimintaan. IoT-teknologian hyödyntämiseen jakeluverkkotoiminnassa käsiteltiin yhtä verkon käyttöön ja sähkön laatuun liittyvää sovellusta, jonka avulla hajautetun pienaurinkotuotannon vaikutuksia pystytään seuraamaan, sekä lisäksi kolmeen eri verkkokomponenttiin kohdistuvaa jatkuvan kunnon seurannan sovellusta. Tämän lisäksi IoT-järjestelmän toteuttamiseksi vaadittavalle analyysi- ja tietojärjestelmäalustalle määriteltiin rakenteellisia ja toiminnallisia tarpeita. Työssä käsitellyistä IoT-sovelluksista lupaavimmaksi todettiin katkaisijoihin kohdistuva jatkuvan kunnonhallinnan sovellus

Impact Analysis and Mitigation of Voltage Regulation Issues in PV Rich Low Voltage Residential Distribution Networks

Modern distribution networks are undergoing major changes with the increased uptake of rooftop photovoltaic (PV) units in low voltage (LV) residential distribution networks. These renewable based distributed energy resources (DERs) impose adverse effects which can propagate from LV to medium voltage (MV) and high voltage (HV) levels. Some of the major areas of concern to network operators include reverse power flow, voltage unbalance, voltage rise, increased harmonics, increased potential of islanding, and component and line overloading. These issues create both an operational mitigation requirement and a need for Distribution Network Service Providers (DNSPs) to adjust LV network design procedures. In Australia DNSPs are bound by strict regulation to provide supply to customers complying with several power quality standards. Australian Standard AS 61000.3.100 requires the voltage at the consumer point of supply to be within +10%, -6% of the 230 V nominal for single phase LV customers. Since residential peak load is typically observed during evening time and power generated from PV during daytime, rooftop PV does little to reduce peak demand. Increased numbers of rooftop PV systems in future LV feeders, combined with increased demand, means DNSPs need to invest in infrastructure to alleviate issues related to overgeneration or overloading and voltage regulation. Traditionally, voltage regulation devices such as on-load tap changers (OLTCs), regulators and capacitor banks have been sufficient to regulate voltage within mandated limits. Bidirectional power flow that arises as a result of DER in LV limits the ability of these devices, as LV voltage issues cannot be detected or do not propagate further up the network. Compared to HV/MV networks, residential LV networks experience more variable loads, have inherent unbalance due to the overhead 4-wire structure, and lack visibility with respect to operational states. This thesis aims to contribute new knowledge and understanding to the field of power distribution network voltage regulation. This includes investigation and analysis of different approaches to voltage regulation in power distribution networks in the literature, and to propose new methods and improvements to existing methods. Specifically, this thesis aims to highlight the shortcomings of the current voltage regulation techniques available to DNSPs in LV feeder. The case studies to be provided in this thesis presents 24 h time series simulation to investigate the performance with varying load and PV generation

Distributed resource integration analysis and network design of electric power distribution systems

The integration of high percentages of distributed energy resources and controllable loads into the distribution system coupled with the strict power quality and service reliability requirements at the power distribution level are necessitating a significant change in the planning, operation and control of the traditional power distribution system. The future power distribution circuits should be able to accommodate the new technologies while simultaneously providing a desired level of power quality and service reliability to the customers. This thesis aims to address the current and future grid requirements of both existing as well as new distribution systems with regard to power quality and service reliability issues. Several methods are proposed to evaluate and mitigate power quality and service reliability concerns due to the integration of smart grid technologies into both existing and new distribution circuits. Notably, for the existing distribution circuits, integration studies are simulated to analyze and mitigate the impacts of electric vehicle loads and photovoltaic generation on the distribution voltages. Furthermore, the problem of siting, sizing and deployment of distributed energy storage systems in meeting distribution planning requirements with regard to integrating distributed generation and providing contingency requirements is also addressed. A new distribution system both grid-connected and operating in islanded mode, however, could be designed to the new requirements. The new distribution circuit could be designed to meet the power quality and service reliability standards directly, thus more efficiently mitigating the concerns. In the thesis, the new distribution circuit design is approached from the perspective of maximizing the service reliability. For the new distribution circuit, approaches to reliability based distribution circuit design are proposed.Electrical and Computer Engineerin

Modelling and analysis of demand response implementation in the residential sector

Demand Response (DR) eliminates the need for expensive capital expenditure on the electricity distribution, transmission and the generation systems by encouraging consumers to alter their power usage through electricity pricing or incentive programs. However, modelling of DR programs for residential consumers is complicated due to the uncertain consumption behavious of consumers and the complexity of schedulling a large number of household appliances. This thesis has investigated the design and the implementation challenges of the two most commonly used DR components in the residential sector, i.e., time of use (TOU) and direct load control (DLC) programs for improving their effectiveness and implementation with innovative strategies to facilitate their acceptance by both consumers and utilities. In price-based DR programs, the TOU pricing scheme is one of the most attractive and simplest approaches for reducing peak electricity demand in the residential sector. This scheme has been adopted in many developed countries because it requires less communication infrastructure for its implementation. However, the implementation of TOU pricing in low and lower-middle income economies is less appealing, mainly due to a large number of low-income consumers, as traditional TOU pricing schemes may increase the cost of electricity for low income residential consumers and adversely affect their comfort levels. The research in this thesis proposes an alternative TOU pricing strategy for the residential sector in developing countries in order to manage peak demand problems while ensuring a low impact on consumers’ monthly energy bills and comfort levels. In this study, Bangladesh is used as an example of a lower-to-middle income developing country. The DLC program is becoming an increasingly attractive solution for utilities in developed countries due to advances in the construction of communication infrastructures as part of the smart grid concept deployment. One of the main challenges of the DLC program implementation is ensuring optimal control over a large number of different household appliances for managing both short and long intervals of voltage variation problems in distribution networks at both medium voltage (MV) and low voltage (LV) networks, while simultaneously enabling consumers to maintain their comfort levels. Another important challenge for DLC implementation is achieving a fair distribution of incentives among a large number of participating consumers. This thesis addresses these challenges by proposing a multi-layer load control algorithm which groups the household appliances based on the intervals of the voltage problems and coordinates with the reactive power from distributed generators (DGs) for the effective voltage management in MV networks. The proposed load controller takes into consideration the consumption preference of individual appliance, ensuring that the consumer’s comfort level is satisfied as well as fairly incentivising consumers based on their contributions in network voltage and power loss improvement. Another significant challenge with the existing DLC strategy as it applies to managing voltage in LV networks is that it does not take into account the network’s unbalance constraints in the load control algorithm. In LV distribution networks, voltage unbalance is prevalent and is one of the main power quality problems of concern. Unequal DR activation among the phases may cause excessive voltage unbalance in the network. In this thesis, a new load control algorithm is developed with the coordination of secondary on-load tap changer (OLTC) transformer for effective management of both voltage magnitude and unbalance in the LV networks. The proposed load control algorithm minimises the disturbance to consumers’ comfort levels by prioritising their consumption preferences. It motivates consumers to participate in DR program by providing flexibility to bid their participation prices dynamically in each DR event. The proposed DR programs are applicable for both developed and developing countries based on their available communication infrastructure for DR implementation. The main benefits of the proposed DR programs can be shared between consumers and their utilities. Consumers have flexibility in being able to prioritise their comfort levels and bid for their participation prices or receive fair incentives, while utilities effectively manage their network peak demand and power quality problems with minimum compensation costs. As a whole, consumers get the opportunity to minimise their electricity bills while utilities are able to defer or avoid the high cost of their investment in network reinforcements

Smart Metering Technology and Services

Global energy context has become more and more complex in the last decades; the raising prices of fuels together with economic crisis, new international environmental and energy policies that are forcing companies. Nowadays, as we approach the problem of global warming and climate changes, smart metering technology has an effective use and is crucial for reaching the 2020 energy efficiency and renewable energy targets as a future for smart grids. The environmental targets are modifying the shape of the electricity sectors in the next century. The smart technologies and demand side management are the key features of the future of the electricity sectors. The target challenges are coupling the innovative smart metering services with the smart meters technologies, and the consumers' behaviour should interact with new technologies and polices. The book looks for the future of the electricity demand and the challenges posed by climate changes by using the smart meters technologies and smart meters services. The book is written by leaders from academia and industry experts who are handling the smart meters technologies, infrastructure, protocols, economics, policies and regulations. It provides a promising aspect of the future of the electricity demand. This book is intended for academics and engineers who are working in universities, research institutes, utilities and industry sectors wishing to enhance their idea and get new information about the smart meters

Increasing the capacity of the Low Voltage Distribution Networks using All-SiC AC-AC Converters

Towards 2020, future energy scenarios predict an excessive penetration of distributed generation (DG) in low voltage (LV) networks as well as a significant uptake of electric vehicles (EVs) and electro-heating. The Distribution Network Operators (DNOs) in UK will face significant challenges towards this de-carbonised electricity generation and consumption shift. The deployment of these so-called low carbon technologies (LCTs) will impact the performance of the distribution network in such way where solutions will be needed to maintain capacity, reliability and the availability of the electricity supply to customers. The practise to put more copper on the ground – reinforcement - in order to facilitate these changes is found to be expensive and disruptive to the public and business. An innovative solution proposed in this thesis is to increase the voltage along the distribution feeders and step it back down at a customer’s premises. Results show that a significant increase at the hosting capacity of the existing network can be achieved and power quality problems such as overvoltage caused by DG can be avoided. The voltage step-down device, which is termed a voltage control unit (VCU), is to be located in the meter-box of each house. This location raises challenges round the temperature rise in the box caused by VCU losses, and the subsequent effect on the electricity meter and cut-out fuse. It also imposes constraints on the size and weight of the VCU so that a very high efficiency design is required, with high power density and small mass. The optimum VCU design was found to be a power electronic AC Chopper using new Silicon Carbide (SiC) MOSFETs and diodes. The technology was demonstrated by designing, constructing and testing two interleaved, parallel operation, 1 kW AC Chopper modules. Results from the prototype were compared against Spice simulation results and theory and confirmed that the target efficiency of 99% was achieved

Scenarios for the development of smart grids in the UK: synthesis report

‘Smart grid’ is a catch-all term for the smart options that could transform the ways society produces, delivers and consumes energy, and potentially the way we conceive of these services. Delivering energy more intelligently will be fundamental to decarbonising the UK electricity system at least possible cost, while maintaining security and reliability of supply. Smarter energy delivery is expected to allow the integration of more low carbon technologies and to be much more cost effective than traditional methods, as well as contributing to economic growth by opening up new business and innovation opportunities. Innovating new options for energy system management could lead to cost savings of up to £10bn, even if low carbon technologies do not emerge. This saving will be much higher if UK renewable energy targets are achieved. Building on extensive expert feedback and input, this report describes four smart grid scenarios which consider how the UK’s electricity system might develop to 2050. The scenarios outline how political decisions, as well as those made in regulation, finance, technology, consumer and social behaviour, market design or response, might affect the decisions of other actors and limit or allow the availability of future options. The project aims to explore the degree of uncertainty around the current direction of the electricity system and the complex interactions of a whole host of factors that may lead to any one of a wide range of outcomes. Our addition to this discussion will help decision makers to understand the implications of possible actions and better plan for the future, whilst recognising that it may take any one of a number of forms