Figure 7: The forward FTPN model of protection scheme for fault at 275 kV north bus bar of Kapar substation. The marking state of FTPN before occurrence of fault. The token in shows absence of fault, and firing transition indicates the occurrence of fault. Tokens in places , , and indicate the readiness of main, local backup, and breaker failure relays, respectively. The broken lines show the FTPN route in its firing sequences (in the case of correct operation of main relay and circuit break).