Damping of power system oscillations using adaptive thyristor-controlled series compensators tuned by artificial neural networks

A proportional-integral (PI) controller is designed for thyristor-controlled series compensators (TCSCs) to improve the damping of power system oscillations. To maintain a good damping characteristic over a wide range of operating conditions, the gains of the PI controller are adapted in real time, based on online measured transmission line loadings (real and reactive power flows). To speed up the online gain adaptation process, an artificial neural network which is capable of performing complicated computations in a parallel, distributed manner is designed. A major feature of the proposed adaptive PI controller is that only physically measurable variables (real and reactive power flows over the transmission line) are employed as inputs to the adaptive controller. To demonstrate the effectiveness of the proposed adaptive TCSC controller, computer simulations are performed on a power system under disturbance conditions. It is concluded from the simulation results that the proposed adaptive TCSC controller can yield satisfactory dynamic responses over a wide range of operating conditions. Low-frequency oscillations in the frequency range 0.3-2Hz have been effectively damped by the proposed compensators