论文标题
两核对称相位角度调节变压器的智能保护和分类
Intelligent Protection & Classification of Transients in Two-Core Symmetric Phase Angle Regulating Transformers
论文作者
论文摘要
本文研究了基于时间和时频特征的分类器的适用性，以区分内部故障和其他瞬变 - 磁化弹药，交感神经inrush，带有电流变压器饱和的外部故障和过度发射 - 用于间接对称的对称相位相位角度调节变压器（ISPAR）。然后，ISPAR的故障变压器单元（串联/令人兴奋）已找到，或者确定了瞬态干扰。事件检测器检测差分电流的变化，并注册一个三相瞬态样品的一环，这些样本用于提取训练七个分类器的时间和时间特征。使用了三组不同的特征 - 使用决策树，随机森林特征选择以及最大相关性最小冗余，从详尽的搜索中获得了三个不同的特征，时间域特征以及时间和小波能量的组合。内部故障以99.9％的平衡精度检测到，有故障的单元以平衡精度为98.7％，而无故障瞬变则以平衡精度为99.5％。结果显示了准确的内部故障检测和定位以及瞬态识别的潜力。提出的方案可以监督现有的基于微处理器的差异继电器的操作，从而提高稳定性和可靠性。通过改变几个参数，对ISPAR进行建模，并在PSCAD/EMTDC中模拟瞬变。
This paper investigates the applicability of time and time-frequency features based classifiers to distinguish internal faults and other transients - magnetizing inrush, sympathetic inrush, external faults with current transformer saturation, and overexcitation - for Indirect Symmetrical Phase Angle Regulating Transformers (ISPAR). Then the faulty transformer unit (series/exciting) of the ISPAR is located, or else the transient disturbance is identified. An event detector detects variation in differential currents and registers one-cycle of 3-phase post transient samples which are used to extract the time and time-frequency features for training seven classifiers. Three different sets of features - wavelet coefficients, time-domain features, and combination of time and wavelet energy - obtained from exhaustive search using Decision Tree, random forest feature selection, and maximum Relevance Minimum Redundancy are used. The internal fault is detected with a balanced accuracy of 99.9%, the faulty unit is localized with balanced accuracy of 98.7% and the no-fault transients are classified with balanced accuracy of 99.5%. The results show potential for accurate internal fault detection and localization, and transient identification. The proposed scheme can supervise the operation of existing microprocessor-based differential relays resulting in higher stability and dependability. The ISPAR is modeled and the transients are simulated in PSCAD/EMTDC by varying several parameters.
