tailieunhanh - From Turbine to Wind Farms Technical Requirements and Spin-Off Products phần 7

Các bản vẽ kỹ thuật để chế tạo là sản phẩm cuối cùng của khâu thiết kế. Chúng phải thỏa mãn hai mục đích: bao gồm đầy đủ tất cả các thông tin cần thiết để chế tạo và cũng còn là một tiêu chí kiểm soát kỹ thuật đối với các mức độ sửa chữa. Trước cuối thế kỷ 20, rất nhiều bản vẽ kỹ thuật được thực hiện bằng tay với sự trợ giúp của bảng vẽ cơ khí. Sự ra đời của máy tính với giao diện người dùng đồ họa đã có thể giúp thực hiện. | Control Scheme of Hybrid Wind-Diesel Power Generation System 79 parameters and system nonlinearities etc. result in system uncertainties. The SMES controllers in these works have been designed without considering system uncertainties. The robust stability of resulted SMES controllers against uncertainties cannot be guaranteed. They may fail to operate and stabilize the power system. To enhance the robustness many research works have been successfully applied robust control theories to design of PSS and damping controllers of flexible AC transmission systems FACTS devices. In Djukanovic . 1999 and Yu . 2001 the structured singular value has been applied to design robust PSS and static var compensator SVC respectively. In Zhu . 2003 and Rahim Kandlawala 2004 the H control approach has been used to design robust PSS and FACTS devices. The presented robust controllers above provide satisfactory effects on damping of power system oscillations. Nevertheless selection of weighting functions becomes an inevitable problem that is difficult to solve. Furthermore an order of designed controller depends on that of the system. This leads to the complex structure controllers. In wang . 2002 and Tan wang 2004 the robust non-linear control based on a direct feedback linearization technique has been applied to design an excitation system a thyristor controlled series capacitor TCSC and a SMES. However the drawback of this design method is a tuning of Q and R matrices for solving Riccati equation by trial and error. Besides the resulted controllers are established by a state feedback scheme which is not easy to implement in practical systems. This chapter presents a controller design of programmed pitch controller PPC and Energy storage ES to control frequency oscillation in a hybrid wind-diesel power generation. To take system uncertainties into account in the control design the inverse additive perturbation is applied to represent all unstructured uncertainties