Comparative study between HDP and PSS on DFIG damping control

In this paper, heuristic dynamic programming (HDP) based supplementary control is compared with the power system stabilizer (PSS) based supplementary control for doubly-fed induction generators (DFIG), namely, the active power damping control. The traditional design of PSS control on DFIG damping is based on eigenvalue analysis. For such analysis, disturbances are considered sufficiently small to permit the nonlinear model representing the power system to be linearized and expressed in state space form. When the disturbance or the system configuration changes, this kind of design is easy to become entrapped in local minimal and the robust ability of the controller is not guaranteed. On the other side, the HDP based supplementary damping controller analyzed in this paper is “model-free” with on-line learning capability: once a system state is observed, an action will be subsequently produced based on the performance index function. The obtained results by such a HDP supplementary controller on a benchmark power system are compared with the traditional PSS controller, demonstrating the improved control performance and robustness.