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В дослідженні запропоновано використання методів прогнозування на основі штучних нейронних мереж для розрахунку та прогнозування втрат електричної енергії. Розрахунок втрат електричної енергії виконувався на тестовій мережі CIGRE. Для визначення втрат електричної енергії було розроблено декілька підходів: прогноз втрат електричної енергії за допомогою штучних нейронних мереж, та розрахунку втрат використовуючи прогноз вузлового навантаження на основі штучних нейронних мереж, які порівнювались з класичним методом розрахунку втрат за коефіцієнтами літнього та зимового максимуму навантаження В залежності від задач прогнозування, при використанні штучних нейронних мереж величина втрат електричної енергії в розподільчих мережах зменшилась в тричі у порівнянні з розрахунком втрат за допомогою коефіцієнтів. This study proposed the use of forecasting methods based on artificial neural networks for calculating and forecasting energy losses. The calculation of energy losses was performed on the CIGRE test network. Several approaches were developed to determine energy losses: prediction of electrical energy losses using artificial neural networks, and calculation of losses using nodal load prediction based on artificial neural networks, which were compared with the classical method of calculating losses based on summer and winter peak load coefficients. Depending on forecasting problems, when using artificial neural networks, the amount of electrical energy losses in distribution networks decreased by three times compared to the calculation of losses using coefficients.

Standards are formulated to meet the generally recognised demands, minimum performance and safety requirements, as well as to make sure that the product from different manufacturers is similar and consistent. A survey is done on the evolution of national standards for transformers and of the range of IEC / IEEE standards available today for transformer engineers. Of course, standards are dynamic and are under continuous revisions and additions. Hence, no claim is made that the listings provided are the latest or include all relevant standards connected with transformers. A listing of standards, if made, as in this contribution in groups – viz. Application guides, Specification, Testing, Transformer Oil, Accessories, Raw Materials, Installation, Operation, Maintenance and Protection, with relevant IEC and IEEE standard numbers for each subject – will be useful as a quick reference for transformer engineers engaged in the selection, procurement, manufacturing, testing, installation, operation, maintenance, and protection of transformers. A list of CIGRE technical brochures relevant to transformers is also included.

This paper is framed within the context of intra-day optimal control of polygeneration systems and storage connected to microgrids. In particular, the paper proposes an optimal control strategy that accounts for both electrical and thermal processes taking place in multi-building energy networks. To this end, the proposed optimal control strategy, based on the use of a Model Predictive Control, has been developed with the aim of providing optimal resource set-points for the coming 24 h. The proposed approach takes into account: day-ahead and spot prices of electricity, resource prices in terms of fuel cost and shut-down, start-up costs as well as the presence of electrical and thermal storage. The ability of this thermo-electric optimal control strategy is then demonstrated through simulations considering three case studies, namely: (a)fixed electricity price, (b)electricity spot-price and (c)different seasonal cases. The paper also studies the shaving of peaks through the use of optimally sized units in a system with the proposed method.

Tento článek vznikl za podpory interních projektů SVK-2018-005 a SGS-2018-023. This paper deals with the topic of high voltage circuit breakers’ reliability in relation to theirs design and service conditions. The motivation for the subject comes from multiple failures analyses and continuous efforts to maintain power systems safe and reliable. The paper contains evaluation of three international surveys done by CIGRE and it evaluates the trends in circuit breakers’ reliability and its effects on design and service operations.

An improvement in the assessment of harmonic emissions as contributed by renewable generation such as a Photovoltaic (PV) plant, at a Point of Connection (PoC) to a distribution network, is needed. Both the generating source and the distribution network contribute to the voltage harmonic distortion at the PoC and single-point measurements cannot be used to quantify the relative contributions of each source. IEC 61000-4-30 Class A PQ measurements are used as a reference dataset for engineers and can be obtained simultaneously at different points in a network in an attempt to better understand the relative contribution by the source of distortion and the voltage supply network. The opportunity to improve the CIGRE/CIRED C4.109 approach by means of multiple-point synchronized network data is shown to be significant in the qualification of the statistical method but lacks the quantification in calculating the harmonic emission of a non-linear load. The CIGRE/CIRED method can be improved by only considering those harmonic currents identified as emission as some harmonic currents could be the result of background harmonic voltages in the supply network. Constraints in using IEC 61000-4-30 time-aggregated rms voltage and current values to support the assessment of harmonic emission using field-measured data is lastly shown as the calculation method and measurement uncertainty influence the compliance to grid code requirements on harmonic emissions.

In this paper we have presented HVDC Rectifier station Model using PSCAD-EMTDC. Here HVDC system is modelled using CIGRE Benchmark circuit. A Benchmark model provides a common base for trying out new concepts and to compare simulation results. It also provides a base to study the advantages of HVDC over AC systems. Here HVDC Rectifier Station is modelled and its results are also plotted, so that PG student can understand evaluation of software for simulation purposes.

RESUMEN: Esta tesis desarrolla una metodología para la mejora en la implantación de sistemas de gestión dinámica de las líneas aéreas de alta tensión en tiempo real y a corto plazo basada en la medida puntual de las condiciones ambientales. Los sistemas actuales cuentan con debilidades que hacen complicada e ineficiente la operación basada en la gestión dinámica. Esta tesis trata de reforzar esas debilidades. En primer lugar, se crea una metodología para el emplazamiento más adecuado de los sensores necesarios para la gestión dinámica. A continuación, se estudian las desviaciones en los cálculos de la capacidad de los conductores creando procedimientos de optimización de los cálculos. Por último, y debido a la gran necesidad de planificar la gestión dinámica a corto plazo, se plantea un sistema de predicción de las variables meteorológicas y de predicción directa de la capacidad de las líneas. Todos los procedimientos se aplicarán a una línea de alta tensión existente. ABSTRACT: This Thesis develops a methodology to improve the implementation of dynamic management systems of overhead transmission lines in real time and in the short term. This methodology are based on multiple measures of environmental conditions. Current systems have weaknesses that complicate and make inefficient the dynamic exploitation. The aim of this Thesis is to address existing weaknesses. Firstly, a methodology to achieve a suitable location of the sensors is created. In a further step, deviations in calculations of capacity of the conductors are studied to obtain procedures for the optimization of the calculations. Finally, due to the great need to plan the dynamic management in the short time, a forecasting system of environmental conditions and of direct capacity of the lines is raised. The different procedures are applied to a real case line.

In HVDC system there's no need to consider the synchronous stability and huge transmission capacity, so the HVDC system is widely used inlarge area grid interconnectionand high-capacity long-distance transmission system.And thus its potential applications in China are very broad. This research is based on the CIGRE HVDC Benchmark Modelin PSCAD software,the test system is often used for HVDC control studies as the standard system, we can add similar program and emulator to the main circuit modelfor different DC control equipment and control strategies[1]In this paper we deeply researched the bus voltage and current level in weak AC system. The results show that CCC is more stable than LCC, while the weak AC system befalls signal-phase fault or three-phase fault.CCC is less prone to commutation failure.

This paper presents the comparison of back-flashover rate (BFR) by applying the CIGRE method and the IEEE-Flash software. The BFR on 230 kV single and double circuits transmission lines have been compared. Firstly, the BFR from the two iterative methods, CIGRE and the simplified methods, have been compared then the BFR using CIGRE method has been chosen in order to compare the results with the IEEE-Flash software. The IEEE-Flash software gives the BFR significantly higher than the CIGRE method for 230 kV double circuits but not for the single circuit.