| Excellent braking performance and high reliability are required when wind turbine needsto stop and brake under the condition of super speed, trouble clearing and routine maintenanceand it is inconvenient for the wind power brake to modify at high altitude operations. China’swind power industry has experienced a blowout period in the past two years, the wind turbinehas been installed, but failure rate is relatively high, and it’s more important to manufacturegood wind power brake. However, the brake inertia bench is the most direct and effectiveequipment to detect brake performance. The brake inertia bench has not been in the market sofar and the brake inertia bench which has good design performance has important theoreticalvalue and practical value. The project research and design wind power brake inertia bench,including the determination of equivalent inertia calculation method, finite element analysisof inertia flywheel, selection of the main drive motor, structural design and performancecalculations of different parts and experimental test. The main results of the work are asfollows:(1) The wind turbine’s equivalent inertia calculation was proposed. The determination ofequivalent inertia was relatively complex compared with automotive, industrial brake inertiabench. It involved the calculation of the wind wheel pneumatic torque and blades inertia andhad caused great difficulties for the calculation of the equivalent inertia. It would bereasonably simplified by ignoring the secondary elements like the leaves’ complex structurematerials, the geometric angle of attack and incidence changes and modifying leaves’ centerof gravity position with reference to empirical data. Simplified calculation method was givenand tested feasibly.(2) The finite element strength analysis of the inertia flywheel and the combinatorialoptimization of flywheel group were proposed. The structural strength of the inertia flywheelwas directly related to inertial bench work safety and reliable performance. Inventor softwarewas used to do the finite element analysis of the inertia flywheel structural strength, considering the working conditions of the rated speed and125%speed of the work condition.The analysis result was given and the inertia flywheel could meet the performancerequirements of specified conditions. Suggestion was given to further optimization of theflywheel’s geometry structure.(3) The choice method of the wind power inertia bench main drive motor was given. Themotor capacity which was calculated by traditional calculation method was too large and theequivalent inertia of the wind turbine was relatively large. In order to solve this problem,customized motor was made to increase the ability of motor’s anti-torque under the conditionof not to change the motor’s capacity. The motor could also satisfy brake cycle requirement inthe experiment and satisfy power requirement of the inertia bench with appropriate motorcapacity.(4) Test measurement and analysis were made to inertia bench. It included brakeperformance test of the original brake, analysis of the test data, and proposition of braketorque, friction coefficient curve in the brake testing process. The inertia bench test could givebreak time, friction coefficient, friction plates, brake disc temperatures under different loadsand can test, collect and analyze the various performance parameters of the brake. It alsocould test whether torque recession and other braking performance would happen when thewind power brake under high temperature conditions.(5) The inertia bench did not only test the brake performance of the wind power brake,but it could also test brake performance of industrial brake. The inertia bench could also havethe function to test static torque.Calculation method of wind turbine and choice method of main driver motor are theinitiative contents. They provide a theoretical basis for the formulation and improvement ofknowledge rules in the wind power area and they have practical value. |
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