Reactive Power Compensation under the Conditions of Distorted Currents and Voltages

Matters concerned with improving the energy efficiency of modern industrial enterprises are addressed. The article presents the results of an instrument-assisted analysis aimed at studying the performance of power supply systems of industrial enterprises in the agricultural sector with an installed capacity of 7–15 MV•A containing their own generation facilities. Such enterprises are characterized by high reactive power absorption and the presence of spontaneous higher harmonic current components caused by the availability of nonlinear loads. Such conditions result in a high failure rate of reactive power compensation (RPС) devices. Despite the satisfactory total harmonic distortion coefficient (THD) for voltage, which does not exceed 5.5 %, the THD for current reaches 70 % or more. The cumulative effect from such operating conditions is the development of an emergency mode in the power supply system. The article considers methods for solving the problems of current and voltage waveform distortion and stabilizing the electric power quality in the presence of RPC devices. The electromagnetic transients that occur during the operation of combined reactive power compensation and harmonic filtering devices are simulated for a power supply system fragment. On the simulated oscillograns of currents, voltages, active and reactive power, the article has demonstrated the effects on decreasing the waveform distortion level and how the RPC devices operate at their connection point given a determinate level of the harmonic spectrum and the operation of several passive filters.