whereby and i1=id(t0) τ1=Le1/re1. B.2.Operation of the DFIG system including the C-FCL in the fault condition At the three-phase fault occurs in the terminal of the DFIG. As discussed in section II, there are t=t0, two modes of operation during the fault, as follows: Mode-I) when is higher than and the is ON: id idc SC-FCL Considering Fig. 4(a), from to the switching state is 000. In this condition, is in the discharging t0 t1, Ld state. Therefore, expression is as (14). At the switching state changes to 100. As is clear from Fig. id t=t1, 4(a), increases until it reaches at So, from to because is higher than expression is idc id t=t2. t1 t2, id idc, id similar to (14). At reaches and the next mode of operation starts. t=t2, idc id Mode II-A): when is equal to and the is ON id idc SC-FCL At the charging state of begins. Fig. 4(b) shows the equivalent circuit in this condition. As the t=t2, Ld equivalent circuit reveals, is equal to and only diodes of and are ON. The differential id idc D2 D4 equation of can be expressed as (15). id whereby , , , and . With regard to (11), can be written as (16) [35]. Equation (17) is derived by using (15), that is the expression of in the charging mode: id whereby and At reaches So, the I0=id(t2), t=t3, id Ic. θsωs=Arctan(Le2sωs/Re2), next mode of operation commences during the fault. Considering Fig. 4(a), at Mode II-B): when is equal to and the is OFF: id idc SC-FCL t=t3, idc
whereby i1=id(t0) and τ1=Le1/re1. B.2.Operation of the DFIG system including the C-FCL in the fault condition At t=t0, the three-phase fault occurs in the terminal of the DFIG. As discussed in section II, there are two modes of operation during the fault, as follows: Mode-I) when id is higher than idc and the SC-FCL is ON: Considering Fig. 4(a), from t0 to t1, the switching state is 000. In this condition, Ld is in the discharging state. Therefore, id expression is as (14). At t=t1, the switching state changes to 100. As is clear from Fig. 4(a), idc increases until it reaches id at t=t2. So, from t1 to t2, because id is higher than idc, id expression is similar to (14). At t=t2, idc reaches id and the next mode of operation starts. Mode II-A): when id is equal to idc and the SC-FCL is ON At t=t2, the charging state of Ld begins. Fig. 4(b) shows the equivalent circuit in this condition. As the equivalent circuit reveals, id is equal to idc and only diodes of D2 and D4 are ON. The differential equation of id can be expressed as (15). whereby , , , and . With regard to (11), can be written as (16) [35]. Equation (17) is derived by using (15), that is the expression of id in the charging mode: whereby I0=id(t2), θsωs=Arctan(Le2sωs/Re2), and At t=t3, id reaches Ic. So, the next mode of operation commences during the fault. Mode II-B): when id is equal to idc and the SC-FCL is OFF: Considering Fig. 4(a), at t=t3, idc
IET%20Second%20Revised%20Manuscript.docx