Investigation of the Efficiency of the Capacitor Voltage Control Circuit of a Unified Electricity Quality Regulator to Reduce Voltage Fluctuations

Abstract

This article investigated the effectiveness of using a unified power quality regulator (UPQR) to reduce voltage fluctuations in electrical networks with a rapidly changing nonlinear load. It is proposed to use a voltage control scheme on the URYAE storage capacitor based on an FIR filter in order to minimize rapid voltage changes and the flicker indicator, as well as the total coefficient of harmonic distortions in the distribution system. The final simulation of the study is carried out using MATLAB/Simulink. To demonstrate the effectiveness of the proposed control scheme, a comparison of simulation results with a PI controller is made from the point of view of improving the specified power quality indicators. The initial data for performing calculations of voltage fluctuations are information on the parameters of the electrical network and the graph of a random, rapidly changing electrical load. Rapidly changing loads cause rapid changes in the network voltage, the amplitudes of which can reach unacceptable values, for example, in the case of frequent start-ups of an asynchronous motor with a large starting current. Voltage fluctuations can also be caused by technological installations, the operation of which is accompanied by active and reactive power surges , such as the drive of reversible rolling mills, arc steel melting furnaces, contact electric welding installations, etc. The main task of the research is to improve the quality of electricity, and, as a result, to increase the service life of electrical equipment and to ensure the conditions for the normal technological process of electricity consumers. Indicators characterizing voltage fluctuations were quantified: voltage change range (δU_t) and flicker indicator (P_t). The effectiveness of the new capacitor voltage control scheme for reducing higher current harmonics compared to the classical one based on the PI-regulator is verified.