257487.fig.0015a
(a)
257487.fig.0015b
(b)
257487.fig.0015c
(c)
257487.fig.0015d
(d)
Figure 15: Experimental results of a single-phase system under grid fault based on the single-phase theory and T/4 Delay sag detection method: (a) grid voltage : 100 V/div and grid current : 5 A/div; (b) active power : 500 W/div and reactive power : 500 Var/div; (c) dynamic performance of grid voltage and current at the start of sag; (d) dynamic performance of grid voltage and current at the end of sag.