Conventional method of power system analysis uses predefined values of transmission line electrical parameters which are considered uniformly distributed along the overhead lines. Conductor temperatures of transmission lines are dependent on the time and space-varying nature of the external conditions, including weather which affects the line electrical parameters. A steady-state power system analysis method is developed in this thesis which is capable of integrating the dynamic line rating approach coupled with the non-uniform distribution of line electrical parameters. The proposed temperature-dependent power flow method provides a realistic representation of a power system network as well as offers a better estimate of system power handling capability with the development of temperature-dependent continuation power flow method (TD-CPF). Uncertainty in weather conditions data can also be coupled with the proposed method. The temperature-dependent steady-state analysis method is extended to incorporate the transient heat balance conditions of a system especially during change in system loads or branch contingencies. The proposed temperature-dependent power system analysis method was automated and its impacts on the large-scale system studies were investigated.