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Figure 2.19 shows an improved load voltage profile compared to similar intentional islanding conditions described in Section 2.5.3.1. During three-phase to ground fault (i.e. between 1.0 and 1.5 s), a voltage spike observed at the switching of intentional islanding of load at an instant of 1.0 s. The load voltage settles to 0.95 pu thereafter during the three-phase fault. The load voltage attains 1 pu during the healthy condition during 1.5 to 2.0 sec.

Figure 2.19 Load voltage profile in test case-2.

At 2.0 s phase to ground fault occurs on phase A. The voltage spike is encountered at this instant due to switching of intentional islanding. During the single-phase to ground fault (i.e. between 2.0 and 2.5 s), the load voltage is around 0.95 pu. After clearing of single-phase to ground fault, the load voltage becomes 1 pu.