Method for designing stabilizer in transmission shaft system of double-feed wind turbine generator and stabilizer

Abstract

The invention relates to a method for designing a stabilizer in a transmission shaft system of a double-feed wind turbine generator and the stabilizer. The method for designing the stabilizer in the transmission shaft system of the double-feed wind turbine generator comprises the steps that a complex frequency domain closed-loop transfer function E(s) between an electromagnetic torque increment delta Te and a motor rotating speed increment delta omega g is obtained, the complex frequency domain closed-loop transfer function E(s) is decomposed into E(s)=dH(s), the phase position theta H at the position of the reversing oscillation frequency omega i under the rated operating condition is obtained, the offset angle phi of the stabilizer is determined according to the phase position theta H, and the transfer function Gd(s) of the stabilizer is obtained according to the offset angle phi, and then the stabilizer in the transmission shaft system of the double-feed wind turbine generator is designed. Compared with an existing method for designing the stabilizer, the method for designing the stabilizer in the transmission shaft system of the double-feed wind turbine generator has the advantages that it is guaranteed that the stabilizer has the more effective control performance under the same gain condition, and the method has great significance in reducing torque impact of the transmission shaft system in the transient state, prolonging the mechanical life of the transmission shaft system of the wind turbine generator and improving the reliability of the transmission shaft system of the wind turbine generator.

Description

Technical field [0001] The invention relates to the technical field of wind power generation, in particular to a method for designing a stabilizer in a double-fed wind turbine drive shaft system and a stabilizer obtained by the method. Background technique [0002] Impellers with large inertia (2-6s) and low-speed rotation in doubly-fed wind turbines usually pass through a flexible drive shaft system (including low-speed shafts, gearboxes, high-speed shafts, couplings, etc.) and small inertia (0.4-0.8s), high-speed The rotating generator rotor is coupled. The existence of couplings and gearboxes makes the drive shaft system (or shafting) of the doubly-fed wind turbine generators have lower equivalent mechanical stiffness (0.3~0.6pu / ele.rad). When subjected to disturbances from the mechanical side (such as wind speed changes) or electrical side (such as short-circuit faults, etc.), the drive shaft system will exhibit oscillation characteristics similar to torsion springs (oscilla...

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Problems solved by technology

In fact, due to the dynamic process in the closed-loop loop of the doubly-fed wind turbine, such as the dynamics of the controller (active power outer loop regulator, current inner loop regulator) and the inertia of the control object (motor body), the output of the damping controller and The phase lag between the controlled quantities of the control object (such as electromagnetic torque), whether it is completely ignored or approximated by an assumed time constant to the equivalent electromagnetic torque-the electrical dynamics of the speed loop cannot accurately account for the electromagnetic torque- The phase lag characteristic of the speed loop, the above-mentioned inappropriate simplification will not only affect the control performance of the damping controller, but may also have the opposite effect (causing negative damping) in severe cases

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