Robust Frequency Stabilization of Isolated Wind Diesel Hybrid Power Systems using H{sub}∞ Control

摘要

The robust frequency stabilizer design based on H{sub}∞ control for the isolated wind diesel hybrid power systems is proposed in this paper. The normalized coprime factorization approach is employed to represent system uncertainties in H{sub}∞ control design. The H{sub}∞-based robust frequency stabilizers for a governor in a diesel side and a pitch control in a wind turbine side are designed individually. As a result, the selection of weighting function in H{sub}∞ design is simplified. In addition, the robust stability margin against system uncertainties can be determined without γ-iteration. The designed robust frequency stabilizer not only requires a single feedback input, but also has a low order. Simulation studies confirm that the proposed robust frequency stabilizer is able to damp system frequency oscillation due to random load disturbances as well as changes in wind power inputs. Particularly, the robustness of the designed stabilizer against system parameter variations is much superior to that of the conventional proportional integral based-frequency controller.