Obtaining method for transmission chain high-speed shaft torque of double-fed wind turbine generator

Abstract

The invention provides an obtaining method for transmission chain high-speed shaft torque of a double-fed wind turbine generator, comprising the following steps: obtaining electromagnetic torque of the double-fed wind turbine generator; and obtaining the high-speed shaft torque of the double-fed wind turbine generator. According to the obtaining method for transmission chain high-speed shaft torque of the double-fed wind turbine generator, a torque measurement device is not required additionally, so that the obtaining method is rapid in convergence, accurate in calculation, high in reliability, suitable for obtaining torque under grid faults without depending on complete mathematical models in conventional systems, and higher in adaptive ability.

Description

technical field [0001] The invention belongs to the technical field of wind power generation, and in particular relates to a method for obtaining high-speed shaft torque of a doubly-fed wind turbine transmission chain. Background technique [0002] Doubly-fed wind turbines are one of the mainstream models of wind turbines in operation in China. According to previous reports, gearbox failures account for the largest proportion of unit downtime and maintenance caused by fan failures, bringing extremely high system operation to wind farm owners. and maintenance costs. The high-speed shaft is a component that is prone to failure in the transmission chain of the doubly-fed wind turbine, and the failure of the high-speed shaft is mainly caused by fatigue damage. The fatigue analysis and life evaluation of the transmission chain need to detect the torque of the transmission shaft. Compared with lateral vibration, the manifestation of torsional vibration is not obvious, which makes...

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Problems solved by technology

The advantage of this method is that it has high sensitivity and wide frequency response range. The disadvantage is that sensors need to be installed on the measured axis. Adding sensors reduces the integration and reliability. In addition, the installation position of the sensor may be limited, and even the original structure of the shaft will be damaged; for large wind turbines, the diameter of the transmission shaft is large, which will lead to a large linear velocity of the sensor, which will reduce the service life of the sensor and increase the measurement error. High requirements for sensor maintenance and signal transmission

[0004] The indirect estimation method does not directly measure the torque. A method for estimating the drive shaft torque based on the torque inverse model has been proposed in the literature. The method proposed in this literature needs the help of the generator speed, electromagnetic torque, wind rotor speed and transmission system parameters (stiffness coefficient and damping coefficient), in which the electromagnetic torque can be calculated based on the electrical signals measured by the current sensor and the voltage sensor, and the generator speed is also easy to measure, but the parameters of the transmission system are not easy to obtain accurately. The accuracy of the model, the accuracy of the model and the accuracy of the measurement will cause errors in the estimation results. The inverse model estimation method proposed in this document cannot guarantee its accurate estimation of torque under power grid faults

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