A robust nonlinear coordinated excitation and SVC controller is proposed to enhance the transient stability of power systems. The SVC is located at the midpoint of the transmission line in a power system. A nonlinear feedback law for the generator is found which linearizes and decouples the power system model. Robust nonlinear control theory is employed to design the coordinated controller which consists of three controllers, an excitation controller and two SVC controllers. The proposed coordinated controller is designed based an local measurements. The design of the resulting controllers is independent of the operating point. Simulation results show that the proposed controller can ensure transient stability of the power system under a large sudden fault, which may occur at the generator bus terminal.