Fig. 9
![Fig. 9](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs41601-018-0079-z/MediaObjects/41601_2018_79_Fig9_HTML.gif)
The response of the proposed and conventional controls of the admittance model of the UPFC for a three phase to ground fault at time t = 1.47 s (operating point ‘A’) on the bus 7 of the test system as shown in Fig. 5, with a lower penetration of the DFIG wind farm which is subjected to a variable wind speed (Fig. 6), where, a the admittance of the UPFC at bus ‘m’ in p.u., b the admittance of the UPFC at bus ‘n’in p.u., c the active power injection of the DFIG (p.u.), and d the interarea oscillation between the generators ‘1′ and ‘4′ in Rad/s, respectively