Robust stabilization of multimachine power system by DFIG wind turbine equipped with power oscillation damper

Various system uncertainties and disturbances may cause the power system instability. The power system stabilizing controller designed without taking such uncertainties into account may not tolerate and fail to operate. This paper aim at the new robust control design of power oscillation damper (POD) equipped with the doubly-fed induction generator (DFIG) wind turbine. Without difficulty of mathematic modeling, the inverse output multiplicative perturbation is used to represent system uncertainties. The structure of POD is specified as a practical 2nd-order lead/lag compensator with single input. The POD parameters optimization problem is formulated considering the variation of tie-line power flows. The POD parameters are automatically tuned by firefly algorithm so that the damping performance and robustness can be achieved. Simulation results in IEEE 9 bus test system ensure that the proposed robust POD is superior to the conventional POD in terms of the damping performance and robustness.