水轮发电机定子铁芯是由硅钢片叠合组装而成。在叠片结束后，必须检查片间是否有气隙或松动，并检查片间绝缘及穿芯螺栓与硅钢片之间的绝缘等情况。如果存在气隙、松动及绝缘不良等情况，在运行过程中会出现振动和局部过热，从而引起定子线棒的绝缘破坏，这对发电机安全运行将造成严重威胁。所以对新叠片或修理过的铁芯必须进行铁芯损耗试验(简称铁损试验)，测定铁芯单位重量的损耗，测量磁轭和磁齿的温度，检查各部温升是否超过规定值。从而综合判断叠片的情况是否符合要求。%The iron core of generator's stator is assembled by the lamination of silicon steel sheets. After the completion of the sheet lamination, it is necessary to ensure there is no air gap or loose between sheets and to check the insulation between sheets and the insulation of punched-core bolt and silicon steel sheets. If there is air gap, loose and poor insulation, the vibration and local over-heat will occur during operation period, which can damage the insulation of stator's wire-bar so that it will bring great threat to the safe operation of generator. Therefore the core loss test should be made for those new laminated sheets or repaired iron-core in order to measure the loss per weight unit and the temperature of magnet yoke and tooth. Then the temperature rise of various positions should be checked to ensure whether such temperature rise exceeds the specified value or not. Thus we can comprehensively judge whether the laminated sheets meet the requirements or not.
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