Nonharmonic Calculator of Electrical Mode Parameters for Microprocessor Terminals

The possibilities for qualitatively improving the characteristics of secondary device functions depend on the performance of information sources. The harmonic analysis methods for electrical signals currently used in these devices have remained largely unchanged. The use of the computational capabilities of modern multi-core microprocessor terminals opens prospects for developing and introducing new digital processing algorithms for power frequency electrical signals based on non-harmonic analysis methods. The article describes the general architecture of a nonharmonic calculator for the main electrical operation mode parameters based on the wavelet-transform and intended to compute orthogonal components of current and voltage vectors, powers, impedances, and frequency. The operation of the proposed nonharmonic electrical mode parameter calculator algorithm is demonstrated through test results performed on a microprocessor relay protection and automation terminal. A real-time computerized facility was used as the electrical signal source. An analysis of the test results has demonstrated the advantages of the non-harmonic calculator over the classical solution, which employs frequency-domain methods for digital signal processing. The new nonharmonic calculator features lower errors in the orthogonal components of vectors in the case of frequency deviations from its nominal value, as well as a more rapid response to changes in operating conditions.