The power system is dependent on a stable and reliable control of active and reactive power to keep its integrity. Loosing this command may lead to a system collapse. It is difficult to load the long extra high voltage ac lines against their thermal limits because of volatility incident in the power system. The aim of this paper is to enhance the transient steadiness of power scheme by establishing simultaneous AC– DC power transmission through a transmission line. With the scheme suggested in this paper, it is more likely to load these lines very close to their thermal limits. The benefit of simultaneous ac-dc transmission is for up gradation of transient steadiness and dynamic steadiness. Damp out oscillations have been established. Simulations have been done in MATLAB software package (Simulink Model).