Control system for fatigue certification experimental test on blades of wind turbine

Abstract

The invention discloses a control system for a fatigue certification experimental test on the blades of a wind turbine. The control system comprises a test bed, a load vibration device, a strain gauge, a bridge-type strain processor, a high-speed synchronous data acquisition card, a computer, a storage and a display, wherein the bridge-type strain processor comprises a shunt calibration module capable of recalibrating the sensitivity of the strain gauge, a bridge circuit temperature compensation module capable of compensating an environmental temperature change, and a linear expansion coefficient error between the strain gauge and a tested blade material, and a strain value return-to-zero module capable of returning the initial strain value of the tested blade to zero; an automatic control monitoring module and a test data processing module are installed in the computer, the automatic control monitoring module is used for comparing real-time test strain signal data with a designed value so as to judge whether the test strain value is in the range of the designed value, and deciding whether the output for an invariable-frequency control signal, a variable-frequency control signal or a shut-down control signal of a frequency converter is kept or not according to the judged result, and the test data processing module is used for converting strain voltage signal data to an actual strain measured value.

Description

technical field [0001] The invention relates to a test control system, in particular to a test control system for wind power generator blade fatigue certification test. Background technique [0002] Wind rotor blades are one of the key components of wind turbines. The design and manufacturing quality of blades directly affect the operating efficiency, service life and performance of wind turbines. With the introduction and digestion of wind turbine blade technology, my country has also begun to independently design and produce megawatt-level wind turbine blades and commercialize them. However, the commercialization of wind turbine blades must be certified by corresponding international organizations. The fatigue certification of wind turbine blades is one of the essential certification items in the IEC (International Electrotechnical Commission) standard. The purpose of the certification is: 1. To discover the irrationality and manufacturing defects in the blade design and ma...

AI Technical Summary

Problems solved by technology

[0004] Since the existing wind turbine blade fatigue certification test system is an open test system without automatic control and monitoring functions, it mainly has the following problems: During the fatigue certification test, once the fatigue strain of the sensitive point of the blade is not within the design value Within a reasonable range, the excitation force of the fatigue test can only be increased or decreased by manually adjusting the output frequency of the frequency converter. However, the fatigue test of a working condition of the blade often takes half a month or even three months. , during the fatigue certification test, the blade is easily affected by factors such as the ambient temperature and the heating of the blade’s own material, and its stiffness will change to a certain extent (for example, when the ambient temperature is low, the stiffness of the blade will increase, and vice versa), thus The strain value of the sensitive point of the blade changes, even exceeding or lower than the strain value of the fatigue design of the blade. Once the fatigue strain value tested is not suitable, it is necessary to manually adjust the output frequency of the inverter to control the sensitive point of the blade. If the fatigue strain of the blade is within a reasonable range, it will not only greatly increase the manual labor load, but also the manual adjustment has great subjectivity, poor accuracy and reliability, and it is easy to make the fatigue strain value of the sensitive point of the blade during the test process If it exceeds or is lower than the fatigue design value, it cannot meet the requirements of the blade fatigue certification test, especially when the blade stiffness changes and the blade natural frequency changes accordingly, it may cause the fatigue excitation frequency to coincide with the blade natural frequency. Resonance, at this time, once the manual treatment is not timely, the risk of fatigue certification test will be greatly increased, and even the safety accident of blade damage will be caused

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