“…Energies 2019, 12 FOR PEER REVIEW 7 In [32] it was shown that the transformation of a signal including numerous frequency components (f1, f2, f3, …) leads to signal () containing components of sums and differences of frequencies f1 ± f2, f1 ± f3, f2 ± f3, … Thus, in the case of faults resulting in amplitude modulation, according to (6) and with consideration for various values of k, m in this dependence, in signal spectrum () frequencies fr, 2·fr, fbf, 2·fbf, etc., should be strengthened. For the purpose of illustrating the characteristic features of the above listed signal processing methods, Figure 1 presents the analysis of a sample amplitude modulated signal.…”