Метод идентификации одиночных утечек тока в фазах распределительной сети, контролируемой автоматизированной системой учета

The paper dwells upon a 0.4-kV four-wire three-phase distribution grid (DG), where energy consumption is monitored by an automated metering system. Phase wires are assumed to have equal unknown non-neutral resistance in each inter-customer section of the DG; the metering system measures the operating voltage, current, and phase angles between the customers as well as at the DG entry point. The paper dwells upon finding the values of, and locating the leakage currents resulting from unauthorized power outtake. It analyzes an earlier proposed method that relies on phase (linear) wire voltage increments to simulate disturbed and desired state of the DG; analysis reveals the disadvantages of this method. The paper further presents a novel solution based on calculating the grid parameters (resistances) and currents in real time. The paper also proposes an algorithm for calculating the grid parameters, which samples data from two different modes of DG operation. Mathematical expressions are shown herein that implement this method and have been tested by computational experiments. The results could be of use in the design of non-process electricity loss metering systems for distribution grids.В работе рассматривается четырехпроводная трехфазная распределительная электрическая сеть (РЭС) напряжением 0,4 кВ, в которой выполняется контроль энергопотребления автоматизированной системой учета. Предполагается, что в РЭС на каждом межабонентском участке сопротивления фазных проводов равны и отличаются от нейтрального, причем их значения неизвестны, а системой учета выполняются измерения действующих напряжений, тока и угла сдвига фаз между ними у всех абонентов и в начале РЭС. Решается задача идентификации значений и места отвода токов утечки вследствие воздействия на РЭС несанкционированных отборов электроэнергии. Проведен анализ предложенного ранее метода, использующего приращения напряжений фазного (линейного) провода для моделированного возмущенного и желаемого состояния РЭС. Показаны его недостатки и представлен новый метод решения указанной задачи, основанный на оперативном расчете и анализе параметров (комплексных сопротивлений) распределительной сети и их токов. При этом предложен алгоритм для расчета параметров сети, для которого необходимы данные двух разных режимов работы РЭС. Получены математические выражения, реализующие предлагаемый метод, проверенные вычислительными экспериментами. Полученные результаты могут быть полезны при разработке систем учета и мониторинга нетехнических потерь электроэнергии в распределительных сетях

Design and Hybrid Simulation of a Larceny Deterrent Energy Evaluation System

The unreliability of the energy system to provide a proper account of energy utilized by consumers has been a huge burden on the distribution system network. Different metering methods and designs to detect and prevent fraud, employed in the past have proven fruitless, thus signalling the need for a much smarter energy metering system. The most frequent problem is electricity larceny, this has incurred a major economic loss in the energy distribution system. To this end, this paper presents the distinctive design and hybrid simulation of a larceny deterrent energy evaluation system, capable of detecting different methods of energy theft within power consumer premises. The method employed comprises of deep understudy of previous work in this field, a model is proposed and is simulated under good working conditions and several theft situations using MATLAB while the hardware is simulated using Proteus 8.1 and Arduino software. In conclusion, the efficiency of the proposed system is evaluated by employing different electric theft algorithms, with the results indicating significant energy cost savings in the distribution network

Transaction-Oriented Dynamic Power Flow Tracing for Distribution Networks – Definition and Implementation in GIS Environment

There is a growing interest from owners of distributed energy resources (DERs) to actively participate in the energy market through peer-to-peer (P2P) energy trading. Many strategies have been proposed to base P2P energy trading on. However, in those schemes neither the costs of assets usage nor the losses incurred are so far taken into account. This article presents a transaction-oriented dynamic power flow tracing (PFT) platform for distribution networks (DNs) implemented in a geographic information system (GIS) environment. It introduces a new transaction model that quantifies the use of the DN, apportions the losses and unlocks a flexible use of the surplus generation enabling that prosumers can adopt simultaneously different mechanisms for participation in energy trading, maximizing renewable energy usage. The platform is also helpful for future distribution system operators (DSOs) to overcome the status invisibility of low voltage (LV) DNs, determine who makes use of the assets, debit the losses on them and explore the effects from new connections. A case study is conducted over the IEEE European LV Test Feeder. The tool provides a clear, intuitive, temporal and spatial assessment of the network operation and the resulting power transactions, including losses share and efficiency of DERs

Análisis multicriterio para la selección óptima de conductores en instalaciones eléctricas en medio y bajo voltaje considerando criterios económicos, de calidad y eficiencia de la potencia eléctrica

El presente artículo establece una metodología genérica para la selección óptima de conductores, el principal objetivo es determinar un conductor óptimo, el cual mantenga un nivel de voltaje adecuado, reduzca pérdidas de potencia y sea lo más económico posible. Para efecto se empleó una metodología multicriterio, la cual se basó en el método CRITIC para relacionar los criterios calculados, el método atribuye ponderaciones o grados de importancia a cada criterio. Los casos de estudio fueron el sistema IEEE 4 y IEEE 13, cada uno con 24 escenarios. Para el cálculo de los criterios analizados, así como el algoritmo de decisión se usó la herramienta computacional Matlab. Entre los principales resultados obtenidos se resaltan una notable mejora en los perfiles de voltaje, las pérdidas de potencia en los conductores disminuyeron, se estableció una relación costo-beneficio entre el costo del conductor y cada criterio analizado. Con lo expuesto anteriormente se pretende dar una solución adecuada para la selección de conductores, en sistemas de distribución.This article establishes a generic methodology for the optimal selection of conductors, the main objective is to determine an optimal conductor, which maintains an adequate voltage level, reduces power losses and is as economical as possible. For this purpose, a multi criteria methodology was used, which was based on the CRITIC method to relate the calculated criteria, the method attributes weights or degrees of importance to each criterion. The case studies were the IEEE 4 and IEEE 13 system, each with 24 scenarios. For the calculation of the analyzed criteria, as well as the decision algorithm, the Matlab computational tool was used. Among the main results obtained, a notable improvement in the voltage profiles stands out, the power losses in the conductors decreased, a cost-benefit relationship was established between the cost of the conductor and each criterion analyzed. With the above, it is intended to provide an adequate solution for the selection of conductors, in distribution systems

Estimação de perdas técnicas e comerciais : método baseado em estimador de estados

Este trabalho apresenta uma metodologia para estimar perdas técnicas e comerciais em alimentadores de distribuição de média tensão, considerando a existência de uma infraestrutura avançada de medição. As perdas técnicas são estimadas para todos os segmentos e as perdas comerciais para todas as barras. A estrutura da metodologia é composta por três processos interdependentes. Primeiro, uma análise de fluxo de carga é realizada para obter os valores iniciais de operação. Segundo, um método de classificação de consumidores é utilizado para obter os pesos das medições de injeção de potência. Terceiro, medições sintéticas são criadas em áreas de baixa redundância local de medição, considerando os conceitos de índice de inovação das medições e n-uplas de medições críticas, com o objetivo de melhorar o desempenho da análise de erros grosseiros do estimador de estados e, como consequência, a estimação de perdas. A validação da metodologia é realizada considerando os alimentadores testes desequilibrados da IEEE de 4, 13 e 123 barras. Os resultados dos testes comparativos apresentam uma redução nos erros de estimação de perdas técnicas e comerciais, ressaltando o aspecto potencial de aplicação em sistemas reais com infraestruturas avançadas de medição.This work presents a framework for technical and nontechnical power losses estimation in medium voltage distribution feeders, considering the existence of an advanced measurement infrastructure. Technical losses are estimated for all segments and nontechnical losses for all buses. The presented framework is composed of three interdependent processes. First, an unbalanced load flow analysis is performed aiming initial system state operation estimation. Second, a consumer data-driven classification method is used to obtain the weights of power injection measurements. Third, synthetic measurements are created in low redundancy areas considering measurements innovation and n-tuple of critical measurements aiming to improve state estimation gross error analysis and, as consequence, loss estimation. Solution validation is made considering the IEEE 4-bus, 13-bus and 123-bus unbalanced test feeders. Comparative test results show decreased technical and nontechnical loss estimation errors, highlighting potential aspects for real-life applications in system with advanced measurement infrastructures