Innovative technique for evaluating electric power distortion in cable transmission line

Abstract

INNovAtIve teChNIque foR evAluAtING eleCtRIC PoweR DIStoRtIoN IN CABle tRANSMISSIoN lINePurpose. The rationale for use of electrical power components produced by current and voltage harmonics with different fre quencies to assess its impact on the electrical energy transmission process.Methodology. PIsection equivalent circuit of the cable line is used. Insulation conductivity is assumed to be infinitely small. Using the results of known studies, the change in active resistance with increasing current frequency is taken into account. The cable power line is represented by a quadripole, whose equations are written in the Aform. With the constant voltage composition at the end of the line, for two cases of alternating nonsinusoidal current at the end of the line, its similar current value and the nonlinear distortion coefficient, the quadripole mode parameters are calculated. Based on the obtained parameters of the line mode, according to the existing methods for determining the power components, their numerical calculation was performed. Ac cording to the results of the analysis obtained power components for the two cases, their concurrency at the beginning of the line and the discrepancy at the end of the line were noted. Based on this, a conclusion was drawn on the low information content of power components calculated by the known method.findings. Using an alternative method for determining the components of instantaneous power, depending on the combination of harmonic frequencies of current and voltage, a number of power distortion indicators are proposed. At the same time active and reactive powers are traditionally used. Performing a numerical calculation of the indicated power indices for the power line, under the conditions of two previously agreed experiments, their effectiveness is demonstrated. It is noted that for the conditions of conducted numerical experiments, the indices of the share of pseudocanonical and noncanonical components differ significantly depending on the distribution of the amplitudes of current harmonics for the same current value, and the nonlinear distortion coefficient originality. The theory of instantaneous electrical power has been developed in terms of power distortion indicators, deter mined taking into account the combination of frequencies of polyharmonic current and voltage in singlephase electrical systems.Practical value. Innovative indicators of electrical power distortion, obtained based on the analysis of the composition of in stantaneous power, reflect the low quality of electrical energy. Additional introduction of the proposed indicators into the electric ity metering procedure is a prerequisite for motivating participants in the process to improve quality.