tailieunhanh - From Turbine to Wind Farms Technical Requirements and Spin-Off Products Part 13

Tham khảo tài liệu 'from turbine to wind farms technical requirements and spin-off products part 13', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Impact of Intermittent Wind Generation on Power System Small Signal Stability 169 Ws Xs 37 So far based on the stator flux-oriented control strategy and considering the decoupled control of the real and reactive power outputs of DFIG the whole reduced practical electromechanical transient DFIG model consists of the following 7th order model Us 0 Uqs U T_ m dIdr dt 2uj xr dr dIdrref dt KUqSXr Ẽ7 KU-X- Xs K- Qef 1 qs dr 1 qs dr - Sret xs Tr T1 Xs Xr T Xs Jl r -1 ỈUd k2 Ậ- - Xl. I dt T2 Tf Kx rp x drref T dr dIqrref dt Ks - - Iqr kU Xu 1 qs X v T T q 1 qs X X qr pc x sref T1 Jl r duar _ 1 ox _ - q- K2 - Ể Iqr dt T2 Tr q - 2 L. rri 1qrref T2 x K2 ặ- Uqr 38 39 40 41 42 43 44 45 46 2 H s - X-U dt Xs 1 q --S I f dr T r m. K -ừ 2 xr ỉdL I _ _fj dt Tqr X 5. Model of wind farm of DFIG type In this chapter a simple aggregated model of large wind farm in the small signal stability analysis is employed. We assume that currently the operating conditions of all wind generators in a wind farm are same and the wind farm is considered to be formed with a number of wind generators jointed in parallel. Therefore the wind farm can be reduced to a single machine equivalent. For a wind farm consisted of N wind generators the values of stator and rotor voltages are same as the value of single machine. The stator and rotor currents are N times larger than the single machine. The stator and rotor resistances and reactances as well as K2 are 1 N larger than the single machine. The remaining control parameters are same as the single machine. 170 From Turbine to Wind Farms - Technical Requirements and Spin-Off Products 6. Small signal stability analysis incorporating wind farm of DFIG type Small signal stability is the ability of the power system to maintain synchronism when subjected to small disturbances Kundur 1994 . In this context a disturbance is considered to be small if the equations that describe the resulting response of the system may be linearized for the purpose of analysis. In .