Traction transformer is a vital equipment in high-speed railway. Insulation status decides its safety and reliability, and frequency domain dielectric spectrum (FDS) test is one of the most effective methods reflecting the changing of insulation status. For field applications, the following problems should be addressed: 1) how to obtain the result of paper insulation from the combined result of oil-paper insulation system; 2) how to discriminate the defects of insulation paper between aging and damp. In this paper, the first problem was transferred to a non-linear equation set, and a CS-DQ algorithm (cuckoo search algorithm optimized by the differential evolution algorithm and the quadratic interpolation method) was proposed to solve it. Then, the insulation states were discriminated by establishing a multi-class LS-SVM (least square support vector machines) model, in which CS-DQ algorithm was also used. Finally, a diagnostic approach for the insulation paper in traction transformer was proposed. The results in laboratory show that the pure result of insulation paper can be obtained and the insulation states can be discriminated effectively by using the proposed approach. Meanwhile the proposed CS-DQ algorithm has better performance than the conventional CS algorithm. The results of field testing also verify the proposed approach.

中文翻译：

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基于FDS测试和CS-DQ算法的牵引变压器绝缘纸状态诊断方法

牵引变压器是高速铁路的重要设备。绝缘状态决定其安全性和可靠性，频域介电谱（FDS）测试是反映绝缘状态变化的最有效方法之一。对于现场应用，应解决以下问题： 1）如何从油纸绝缘体系的综合结果中得到纸绝缘的结果；2）如何区分绝缘纸老化和受潮的缺陷。本文将第一个问题转移到非线性方程组，提出CS-DQ算法（差分进化算法和二次插值法优化的布谷鸟搜索算法）进行求解。然后，通过建立多类LS-SVM（最小二乘支持向量机）模型来区分绝缘状态，其中还使用了CS-DQ算法。最后提出了牵引变压器绝缘纸的诊断方法。实验室结果表明，采用该方法可以获得绝缘纸的纯净结果，并能有效区分绝缘状态。同时提出的CS-DQ算法比传统的CS算法具有更好的性能。现场测试的结果也验证了所提出的方法。实验室结果表明，采用该方法可以获得绝缘纸的纯净结果，并能有效区分绝缘状态。同时提出的CS-DQ算法比传统的CS算法具有更好的性能。现场测试的结果也验证了所提出的方法。实验室结果表明，采用该方法可以获得绝缘纸的纯净结果，并能有效区分绝缘状态。同时提出的CS-DQ算法比传统的CS算法具有更好的性能。现场测试的结果也验证了所提出的方法。