Short Circuit Switches Fault in VSI Upper Fault

N. S. Ahmad , A. R. Abdullah and N. Bahari 195 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 Fig.10. Parameter Estimation for open-circuit fault upper a Instantaneous Average Current, Iavet b Instantaneous RMS Current, Irmst c Instantaneous RMS Fundamental Current, Irmst d Instantaneous Total Waveform Distortion, TWDt

5.3 Short Circuit Switches Fault in VSI Upper Fault

Fig. 11a shows signal short circuit switches fault where three-phase current indicate the fault also occur at phase A where current signal is increase at 0.2 – 0.3 s. At current signal at phase B and C is decrease when fault occur. Based on Fig. 11b, the TFR detect two frequency at faults signal, where fundamental and fault frequency. From the contour, the spectrogram is show three-axis where the detect fault at DC component is 0 Hz and 60 Hz for fundamental frequency. Fig.11. a Signal of Short-Circuit Fault Upper b Spectrogram Short-Circuit Fault Upper Fig. 12 a shows the average current, phase A is higher compare phase B and C at 0.2 – 0.3 s. During the RMS current, the phase A is phase faults occur where the value of current is higher compare with phase B and C as shows Fig. 12b. According Fig.12 c, the RMS fundamental for phase A is momentary decrease but other phase is higher than phase fault occurring. While, value of TWD gives 1.4 percent and phase B and C is below than 1 percent as show Fig. 12 d. 0.1 0.2 0.3 0.4 0.5 0.6 -0.5 0.5 1 Time sec A m p li tu d e Instantaneous Average Current, Iavet C u rr en t, A Time s a Phase A Phase B C Instantaneous RMS Fundamental Current, Irmst Phase A Phase B Phase C Time s c C u rr en t, A 0.1 0.2 0.3 0.4 0.5 0.6 1 2 3 Instantaneous Total Waveform Distortion, TWDt P er ce n ta g e, Phase A Phase B C Time s d 0.1 0.2 0.3 0.4 0.5 0.6 -3 -2 -1 1 2 3 0.1 0.2 0.3 0.4 0.5 0.6 -3 -2 -1 1 2 3 0.1 0.2 0.3 0.4 0.5 0.6 -3 -2 -1 1 2 3 C u rr en t, A P ha se A P ha se B P ha se C Time s a Short-circuit Faults of the Upper Switch Signal F re q u en cy , H z Time Frequency Representation Time s b 0 Hz 60 Hz 0.1 0.2 0.3 0.4 0.5 0.6 0.9 0.95 1 1.05 1.1 1.15 Time s b Instantaneous RMS Current, Irmst C u rr en t, A Phase C Phase A Phase B 196 Open and Short Circuit Switches Fault Detection of Voltage Source Inverter Using Spectrogram Fig.12. Parameter Estimation for short-circuit fault Upper a Instantaneous Average Current, Iavet b Instantaneous RMS Current, Irmst c Instantaneous RMS Fundamental Current, Irmst d Instantaneous Total Waveform Distortion, TWDt

5.4 Short Circuit Switches Fault in VSI Lower Fault