The Study of Error of Determining the Phase Shift

The work examines the error in determining the initial phase of the signal according to the time of the change in its polarity in the conditions of the presence of higher harmonics in its spectrum. A discrete model has been developed that makes it possible to estimate the error in determining the phase shift of the fundamental harmonic of a periodic signal for a different spectrum and sampling rate. The error in determining the phase angle of a harmonic signal using the method of linear interpolation at different sampling rates is investigated. A computing experiment was carried out using stochastic modeling methods for a random spectral composition of the signal. The limiting angular error is determined for different levels of signal non-sinusoidality. It has been established that even with a relatively small level of signal non-sinusoidality (up to 8%), the error in determining the phase shift angle can be quite significant.