In the present paper the coordinated application of the controlled series compensation (CSC) and the SVS auxiliary controllers has been demonstrated for the dynamic and transient performance enhancement of a series compensated long transmission line. SVS controller, known as the combined reactive power and frequency (CRPF) auxiliary controller, has been developed and incorporated in the SVS control system located at the middle of the transmission line. The application of the auxiliary controllers, considerably, enhances the system damping and the unstable system modes are stabilized. To improve the transient performance, the CSC having bang-bang control characteristics has been incorporated. A digital simulation study, using a nonlinear system model, has been performed to illustrate the comparative effectiveness of the CSC and the SVS auxiliary controllers developed.