Calculation of the mode of higher harmonics in electrical networks of plywood production

Abstract

The trouble-free operation of the power supply system elements of plywood production largely depends on maintaining the required quality of electric energy. It is essential to focus on calculation of higher harmonics mode at engineering the power supply system of plywood production, as the process uses powerful semiconductor controlled rectifiers. The article discusses the controlled rectifier that is required for the operation of a four-foot veneer peeling machine. The authors determine that the presented unit generates higher harmonic currents into the network. These currents negatively affect all elements of the power supply system. However, there is no calculation method for the mode of higher harmonics in the power supply system of plywood production. Therefore, the purpose of the research is to develop a methodology for calculating the mode of higher harmonics in electrical networks of plywood production. The experiment was conducted at an operating plywood production in the Kirov region to achieve the research purpose. The investigation object was a four-foot veneer peeling machine. It was found that the higher harmonics generated by the main drive of the veneer peeling machine change randomly. The authors proposed to consider them as random variables in the calculations. The research determined statistical laws of the higher harmonics distribution and their numerical features. The authors obtained analytical expressions for calculating the amplitudes of the higher harmonics through the amplitudes of the main harmonic component of the current in the absence of information about the control and switching angles of the rectifier. The proposed technique allows calculating amplitude spectra of higher harmonic currents in branches and voltages in nodes of the power supply system of plywood production. According to the proposed methodology, the results of calculations are recommended for solving series of practical problems.