In the deregulated electricity market, total transfer capability (TTC) is a measure of the network capability for further commercial activity above the already committed uses. This paper deals with the development of an interior point nonlinear programming methodology for evaluating Dynamic TTC. By establishing a novel method for integrating transient stability constraints into conventional steady-state TTC problem, we have proposed the dynamic TTC solution methodology using a Transient Stability Constrained OPF. In the TSCOPF based TTC formulation, we have assumed that three phase to ground faults will occur in the simulation period. In Japan, power system operator considers more severe faults conditions, like 3 phases 4 lines to ground fault with double circuits (3φ4LG). In this paper, we will propose a solution of Transient Stability Constrained OPF with unbalanced faults, where three phase transmission model was considered in the dynamic simulation period. The proposed method has been implemented and tested on IEEJ WEST30 model systems.