大型汽轮发电机定子线圈F级绝缘寿命预测方法的研究

Study on Life Prediction of Class F Insulation for Stator Coils of Large Turbo-Generators

介绍了大型汽轮发电机定子线圈F级绝缘的老化因子与加速寿命试验方法,对电老化与广义热老化的加速寿命试验数据进行了统计分析;用威布尔分布对F级绝缘的电老化和广义热老化的加速寿命试验数据进行了描述;应用可靠性统计和非线性回归方法确定了F级绝缘电老化与广义热老化寿命计算公式的特征参数;依据寿命损耗累积理论,介绍了电老化与广义热老化同时作用的汽轮发电机定子线圈F级绝缘寿命的预测方法和水冷定子线圈F级绝缘寿命损耗的分配方案.采用2倍额定电压2 UN和3倍额定电压3 UN的电老化寿命的不同下限值,对以电老化为主要老化因子的水冷定子线圈F级绝缘寿命进行了研究.结果表明:应用定子线圈F级绝缘寿命预测方法可以在设计、制造和运行阶段定量预测和评定汽轮发电机定子线圈F级绝缘寿命.

Ageing factors and accelerated life-test methods of class F insulation for stator coils of large turbo-generators are presented, while corresponding accelerated test data of both electrical ageing and generalized thermal ageing summarized and analyzed using Weibull distribution model, and simultaneously rele- vant characteristic parameters of the life calculation formulae determined by reliability and non-linear re- gression statistics methods. Based on the life expenditure accumulation theory, an introduction is presented to a life prediction method for simultaneous electrical ageing and generalized thermal ageing of class F insulation for stator coils of turbo-generators, and to the life expenditure assignment scheme for class F insulation of water cooled stator coils. The lower life limit of class F insulation for water cooled stator coils affected mainly by eleetrieal ageing is studied under 2 UN and 3 UN conditions. Results show that with above prediction method, the life of class F insulation for stator coils of large turbo-generators can be quan- titatively predicted and assessed in the design, manufacture and service stages, thus providing a scientific basis for life determination and extension of relevant insulation in large turbo-generators.