Determination of voltage quality indicators in industrial power supply systems with limited energy system capacity

Purpose. To justify the dependence of the determination of indicators of electromagnetic compatibility of power supply systems of industrial enterprises in the presence of powerful nonlinear and asymmetric loads in conditions of limited power system capacity. Methodology. Methods of theoretical electrical engineering for the construction of replacement schemes of three-phase electrical networks, Fourier series for the analysis of higher harmonics of current and voltage, the method of symmetrical components for the analysis of asymmetry. Findings. Виділено основні показники якості напруги, значення яких залежить від параметрів живлячої електроенергетичної системи (потужності короткого замикання). Наведено аналітичні залежності розрахунку показників несиметрії та несинусоїдальності при обмеженні потужності КЗ. Проаналізовано засоби корекції показників якості в умовах електричних мереж з розподіленою генерацією. Originality. The scientific novelty consists in establishing the patterns of changes in the mode parameters of the industrial load from the parameters of the power system, which is expressed in interrelated changes in voltage quality indicators. At the same time, in the analytical models, the option of obtaining variable changes in the parameters of the power system both due to the generating capacities and through the parameters of the substitution schemes of electrical networks of different voltage classes has been added. Practical value. For engineering calculations, simplified algorithms for determining voltage quality indicators (deviation, oscillation, asymmetry and non-sinusoidal voltage) are proposed, taking into account the real configuration of the electrical network and the actual power of the power system. This makes it possible to evaluate the efficiency of transmission and conversion of electricity under an arbitrary configuration of the post-emergency power supply scheme.