Development of a Method for Digital Synthesis of Electrical Signals with a Normalized Harmonic Coefficient

The widespread use of harmonic signals, especially in the electrical circuits of computer technology and microelectronics, has led to the need to control their real shape. When monitoring the quality of electricity in power networks in the frequency range from 50 Hz to 400 Hz, according to regulatory documents, it is necessary to control the harmonic coefficient of the voltage of the power supply network. The paper proposes a method for digital synthesis of electrical signals with a normalized harmonic coefficient. The developed method is based on a modification of the method for generating a quasi-sinusoidal signal. The essence of the method is to represent the original sinusoidal signal by a piecewise stepwise approximation. In this case, the harmonic coefficient of the synthesized signal is determined by the number of approximation sections. It is substantiated that the more approximation sections, the lower the harmonic coefficient and it asymptotically tends to zero depending on the approximation method. The calculated harmonic coefficient of the synthesized step signal and the relationship between the parameters of such a signal and the parameters of the steps is determined. The resulting ratios allow to calculate the required value of the harmonic coefficient depending on the number of levels of the step signal and with different locations of their switching points in a certain interval. Graphs are constructed based on the obtained dependencies, which confirms the adequacy of the proposed method.