The paper considers the influence of harmonics on the operating of electrical energy meters in a network with nonlinear loads. It is shown that electronic static meters of active energy are tested in the presence of distortions, and electronic static meters of reactive energy accuracy requirements do not take into account the possible presence of harmonics. It is revealed that the maximum influence on the error in active energy metering is exerted by the number of harmonics taken into account and their amplitude, and the error in reactive energy metering is additionally influenced by the phase angle at the fundamental and harmonic frequencies, which has been confirmed in laboratory conditions. Additionally, experimental studies of the capacitor bank’s influence on reactive energy metering has been carried out in the presence of nonlinear electrical loads. It is shown that when capacitor banks are connected, the error in reactive energy measurement and variation range of the phase shift angle of harmonics significantly increases. The assessment of the computational error of reactive power metering according to various equations were carried out based on the field measurements. If the voltage and current distortion values do not exceed the permissible values, the error can be estimated at, at most, 5–7%.

The article provides an analysis of the existing methods of identifying the consumer’s contribution to voltage distortion at a point of common coupling. The considered methods do not allow correctly and fairly determining the source of harmonic distortions, or they have limited application and difficulties in implementation. The paper proposes new methods for determining the source of high harmonics. The developed methods and techniques are based on the analysis of the grid operation modes with two connected consumers using compensating devices, such as reactive power compensation devices and passive harmonic filters. It is shown that the most promising method is the application of harmonic filters, which allows determining the share of the consumer’s contribution to the voltage distortion. The present research is carried out using a computer simulation of the existing electrical grid, to which consumers with nonlinear electric load are connected. These methods can be implemented to assess the power quality and the shareholding of different consumers connected at the point of common coupling. Furthermore, such methods appear to be feasible, as almost every enterprise currently has such facilities in operation.

В статье рассматриваются вопросы выявления местоположения нелинейной нагрузки в электрических сетях, вносящей основной вклад в искажения несинусоидальности напряжения и тока в распределительной сети промышленного предприятия, включая предприятия горнодобывающей отрасли. Рассмотрены существующие методы определения местоположения источника высших гармонических составляющих в напряжении и токе, выявлены их преимущества и недостатки. К основным недостаткам применяемых методов следует отнести невысокую точность и некорректность их использования на действующих предприятиях. При разработке нового метода перед авторами стояла задача простоты его использования в условиях промышленной эксплуатации электрооборудования и безусловной корректности полученных результатов. Предложенный метод выявления источника высших гармоник основан на варьировании параметров энергосистемы, в частности, изменении сопротивления силовых трансформаторов с учетом коэффициента их трансформации. Показано, что при варьировании коэффициента трансформации при регулировании под нагрузкой изменяется суммарный коэффициент гармонических составляющих напряжения. На основании построенных зависимостей проанализировано изменение производной данной функции при различных вариациях параметров источников высших гармоник и разработан метод, позволяющий определить долевой вклад потребителей в суммарный коэффициент гармонических составляющих напряжения.

In this article, the authors consider the possibility of using a hybrid energy storage system to even out the load profile of the enterprise. Solving the problem of rational use of energy storage taking into account the initial variable load schedule will significantly reduce not only the cost of electricity consumption by the enterprise, but also the costs of its production. Detailed characteristics of batteries with various types of electrolytes and supercapacitors are given. A model of the active scheme of a hybrid electric energy storage system consisting of a lithium-ion battery and a supercapacitor unit with the corresponding characteristics is presented. The model was carried out by using the SimPowerSystems software in MatLab. During the simulation, the temperature and the aging effects and of the batteries were not taken into account. The selfdischarge parameter of the battery was also not presented. As a result of the simulation, discharge characteristics of supercapacitors and batteries were obtained based upon which the expediency of their combined use for leveling load profiles of various types was substantiated. The paper presents the results of the simulation of operating modes of a hybrid energy storage device, combining the advantages of two types of energy storage devices, as well as a diagram of delivered power to the network, corresponding to the specified parameters. The paper provides a mathematical description of the increasing power by hybrid storage system resulting from the combined use of supercapacitors and batteries. The paper presents the dependence of the power increase ratio on the frequency and the pulse current duty ratio, which proves that the maximum possible output power of the hybrid storage system can be several times greater than the power of a single battery having the same parameters.

The paper deals with reactive power compensation by means of condenser batteries with harmonic distortions in voltage and current, resulting from internal and external nonlinear load regarding the connection point shared by consumers. The paper presents the dependencies of the capacitor's overloading factor from the required reactive power for compensating. These relations can help to determine in which capacity area of the capacitor banks its operation is ensured without overload. The paper also presents algorithm for selecting parameters of condenser batteries which leads to minimization of the capacitors overload and maximization of the network power factor.

The paper deals with issues of modeling nonlinear electrical loads of various types, such an uncontrolled rectifier, thyristor rectifier, thyristor power regulator and mixed equivalent nonlinear load. For these load types, existing analytical expressions were identified to determine the magnitudes of harmonic currents, and waveforms of currents were obtained during measurements in laboratory conditions with variable parameters of the grid impedance and load. The obtained results were compared, and it was found that the error in determining the magnitudes of harmonic currents can reach 60% for an individual load and 54% for an equivalent load. A more accurate method for determining the parameters of nonlinear electrical load is also proposed, which is based on the application of shunt harmonic filters. In laboratory conditions, it was found that when using the developed method, the error did not exceed 10% for an individual load and 14% for an equivalent load.