核电工程变压器过励磁能力研究

Study on Over-excitation Capability of Nuclear Power Plant Transformer

由于出口核电工程用变压器运行环境的特殊性(低频率、电压不稳定),目前国家标准中的过励磁曲线无法满足发电机变压器组保护整定值计算的需要,对发电机、变压器乃至核电厂的安全运行都有极大的隐患。文章进行变压器过励磁能力的计算分析,开展了硅钢片材料在频率变化时的性能测试,对比了过电压、降频率两种方式或两种条件同时变化的过励磁,得出了设计此类变压器和二次整定保护的一些建议。

Due to the particularity of the operation environment （low frequency, voltage instability） of export nuclear power plant transformer, the current national standard of the over-excitation curve cannot meet the requirement of protection setting value calculation, which has hidden risk for the safe operation of generator, transformer and even the whole nuclear power plant. In this regard, calculation and analysis are carried out for the transformer over-excitation ability. Performance tests are carried out for the silicon steel sheet material in frequency changes. The over- excitation is compared for two ways of over-pressure and frequency reduction or two conditions change at the same time. Some suggestions are given for the design of such transformer, and protection of the secondary setting.