## 6 The Proposed Fault Indicators  
Taking into account the results presented in Section 5, this section proposes an on-line detection using two fault indicators, \(FI_{I}\) and \(FI_{ZSVC}\), which are calculated as the difference between the amplitudes of the two harmonics of the stator currents or the ZSVC, respectively. It is assumed that during fault occurrence, the magnitude of the fault indicator is greater than a pre-established threshold value. Figure 11 shows the flow chart of the proposed approach for detecting eccentricity faults. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Harmonic** & **1** & **3** & **5** & **7** & **9** & **11** & **13** & **15** & **17** & **19** \\ \hline \hline \multirow{4}{*}{Healthy (dB)} & \(-0.34\) & \(-16.91\) & - & \(-24.04\) & \(-38.25\) & \(-42.07\) & \(-39.00\) & - & \(-43.31\) & \(-54.96\) \\  & \(-0.78\) & \(-16.82\) & - & \(-23.76\) & \(-34.92\) & \(-42.87\) & \(-37.80\) & - & \(-48.31\) & \(-57.15\) \\  & \(0.44\) & \(-0.09\) & - & \(-0.28\) & \(-3.33\) & \(0.80\) & \(-1.20\) & - & \(5.00\) & \(2.19\) \\ \hline \hline \multicolumn{10}{c}{**Low-load conditions**} \\ Healthy (dB) & \(-0.39\) & \(-28.33\) & - & \(-43.24\) & \(-30.06\) & \(-39.83\) & \(-58.81\) & - & \(-41.99\) & - \\  & \(-0.40\) & \(-28.08\) & - & \(-42.34\) & \(-29.85\) & \(-39.88\) & \(-57.00\) & - & \(-41.98\) & \(-59.54\) \\  & \(0.01\) & \(-0.25\) & - & \(-0.90\) & \(-0.21\) & \(0.05\) & \(-1.81\) & - & \(-0.01\) & \(59.54\) \\ \hline \hline \multicolumn{10}{c}{**Low-load near \(d\)-position conditions (Current Angle 30\({}^{o}\))**} \\ Healthy (dB) & \(-0.40\) & \(-24.78\) & - & \(-45.93\) & \(-36.45\) & \(-45.89\) & \(-53.65\) & - & \(-52.06\) & \(-45.94\) \\  & \(-0.38\) & \(-31.78\) & - & \(-46.94\) & \(-30.44\) & \(-41.21\) & \(-49.89\) & - & \(-42.64\) & \(-55.53\) \\  & \(-0.08\) & \(-7.00\) & - & \(1.01\) & \(-6.01\) & \(-4.68\) & \(-3.76\) & - & \(-9.42\) & \(9.59\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Spectral content of the stator currents of the analyzed fPMa-SynRM under healthy and 40% static eccentricity conditions. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Harmonic** & **1** & **3** & **5** & **7** & **9** & **11** & **13** & **15** & **17** & **19** \\ \hline \hline \multicolumn{10}{c}{**Rated operating conditions**} \\ Healthy (dB) & \(-1.31\) & \(-12.61\) & \(-20.11\) & \(-33.85\) & \(-34.70\) & \(-44.29\) & \(-36.13\) & \(-41.51\) & \(-55.21\) & \(-40.73\) \\ Faulty (dB) & \(-2.36\) & \(-13.96\) & \(-21.17\) & \(-40.13\) & \(-52.41\) & \(-35.26\) & \(-39.82\) & \(-46.52\) & \(-51.38\) & \(-51.86\) \\ \(\Delta\)dB & \(1.05\) & \(1.35\) & \(1.06\) & \(6.28\) & \(17.71\) & \(-9.03\) & \(3.69\) & \(5.52\) & \(-3.83\) & \(11.13\) \\ \hline \multicolumn{10}{c}{**Low-load conditions**} \\ Healthy (dB) & \(-5.95\) & \(-9.89\) & \(-7.09\) & \(-17.98\) & \(-39.85\) & \(-51.57\) & \(-36.13\) & \(-54.42\) & \(-51.91\) & – \\ Faulty (dB) & \(-6.12\) & \(-10.06\) & \(-7.26\) & \(-18.15\) & \(40.02\) & \(-51.74\) & \(-36.29\) & \(-54.59\) & \(-52.08\) & – \\ \(\Delta\)dB & \(0.17\) & \(0.17\) & \(0.17\) & \(0.17\) & \(0.17\) & \(0.17\) & \(0.17\) & \(0.16\) & \(0.17\) & – \\ \hline \hline \multicolumn{10}{c}{**Low-load near \(d\)-position conditions (Current Angle 30\({}^{o}\))**} \\ Healthy (dB) & \(-4.67\) & \(-5.71\) & \(-12.06\) & \(-22.25\) & \(-36.85\) & \(-51.68\) & \(-39.2\) & \(-41.33\) & \(-55.46\) & – \\ Faulty (dB) & \(-5.48\) & \(-9.37\) & \(-7.31\) & \(-18.98\) & \(-39.61\) & \(-39.01\) & \(-40.24\) & \(-50.21\) & \(-52.04\) & – \\ \(\Delta\)dB & \(0.81\) & \(-3.66\) & \(-4.75\) & \(-3.27\) & \(2.76\) & \(-12.67\) & \(-1.04\) & \(-8.88\) & \(-3.42\) & – \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Spectral content of the ZSVC of the analyzed fPMa-SynRM under healthy and 40% static eccentricity conditions.