The calculating program method of the integrated indicator of grid electromagnetic compatibility with consumers combination of non-sinusoidal currents

Abstract

If you have multiple non-linear consumers connected to the grid there arises the problem of calculating the indicators of the grid electromagnetic compatibility and the combination of these consumers with non-sinusoidal currents. The published calculation methods use a spectral (in harmonic) approach with the definition of multidimensional electromagnetic compatibility (EMC) for each harmonic. The multidimensionality of the result makes it difficult to compare situations with different consumers and to carry out a normalization of the degree of electromagnetic compatibility. Besides, at the total current of the grid there is a partial or total compensation of consumers currents of individual harmonics, as a result the grid current spectrum may be significantly different from those of individual consumers currents regulated by standards. Necessity of calculating mathematical methods of the integral quality of grid current through the integrated quality indicators of individual consumers' currents is visible. This problem was not posed before. The programmed method of calculating the one-dimensional grid EMC index (the grid current THD) with a set of nonlinear consumers connected to the grid through currents THD of individual consumers is presented. The technique is tested by computer simulation for supply with non-linear consumers.