Stator Current Power Spectrum Of Healthy Condition At No-Lood Lab Analysis

In this analysis, the stator current signal transformed to the frequency domain using a FFT algorithm. The stator current signal of the motor is used to analyze and detect specific fault frequencies related to incipient faults. For stator winding fault, there is an associated fault frequency that may be identified in the spectrum. The stator fault has been detected by comparing the healthy power spectrum to faulty power spectrum.
The power spectrum of stator current for healthy no-load condition is as shown in Fig.2. Since, the fundamental Fig.2. Stator Current Power Spectrum of Healthy Condition at No-Load frequency is set 50 Hz; therefore, highest amplitude displayed for this frequency. The fault frequencies will be appeared around the
Power Spectrums of Stator Current for Stator Inter-turn Fault at No-Load Condition, (a) When DC Voltage 460 Volt and Slip 0.01, (b) When DC Voltage 470 Volt and Slip 0.01, (c) When DC Voltage 480 Volt and Slip 0.01
However, for creation of stator inter-turn fault we have exceded overvoltage upto 480 V. Because for inter-turn fault the faulty current will be much higher than the rated current in the shorted path which will cause excessive heating.
The power spectrums for healthy as well as faulty stator winding at no-load is as shown in Fig. 2 and Fig.3. From both figures, It has been observed that as the input voltage is being increased then the sidelobes around the fundamental frequency is also getting increased. Among obtained power spectrums for no-load conditions are different from healthy power spectrums. The left and right side band fault

Fig.4. Stator Current Power Spectrum of Healthy Condition at Full-Load frequencies have been observed 25 and 75Hz with their corresponding amplitudes in dB respectively. It may also be understand from Table.I. Therefore, due to the non-intrusive nature of the wavefroms; we may clearly state that an competent stator inter-turn fault detection has been done in the steady state no-load
The power spectrums of stator current for healthy and stator faulty conditions for full-load are as shown in Fig.4 and Fig.5.
The fault analysis for full load condition has been done for input DC voltage 460 V, 470 V and 480 V when the slip set at 0.08. The obtained power spectrums of faulty conditions have been compared with healthy power spectrums(Fig.4 and Fig.5). It has clrealy been observed that the healthy and faulty stator power spectrums are dis-simlilar from each other. It has also been observed that if the fault severity increased then the side lobes around the fundamental frequency has also been getting increased. It may be shown in Fig.5. (a) (b) (c)
Fig.5. Power Spectrums of Stator Current for Stator Inter-turn Fault at Full-Load Condition, (a) When DC Voltage 460 Volt and Slip 0.08, (b) When DC Voltage 470 Volt and Slip 0.08, (b) When DC Voltage 480 Volt and Slip