Line-commuted converter (LCC)–voltage source converter (VSC) hybrid high voltage direct current (HVDC) transmission system is an innovative technology, the existing LCC and VSC protection require setting, and it is difficult to be directly applied in the LCC–VSC hybrid HVDC, which is a serious problem in practical engineering. A novel linear regression density peak clustering (LRDPC) approach is introduced for transmission line protection. LRDPC employs Least Squares linear regression to compute the fault current slope, followed by density peak clustering for fault type identification. The proposed protection structure is straightforward and setting-less, eliminating the need for fault pole selection elements and classification thresholds. Validation on the Kun-Liu-Long LCC–VSC HVDC RTDS system demonstrates the method's effectiveness in identifying diverse faults under varying conditions, including fault types, locations, resistances, and signal-to-noise ratios. Notably, it remains robust against fault impedance (600 Ω) and noise interference (20 dB).

中文翻译：

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一种新型线性回归密度峰值聚类的线路换流换流器-电压源换流器混合高压直流系统输电线路保护

线路换流换流器（LCC）-电压源换流器（VSC）混合高压直流（HVDC）输电系统是一项创新技术，现有的LCC和VSC保护需要整定，很难直接应用于LCC- VSC混合直流输电是实际工程中的一个严重问题。引入了一种新颖的线性回归密度峰值聚类（LRDPC）方法用于传输线路保护。 LRDPC 采用最小二乘线性回归来计算故障电流斜率，然后通过密度峰值聚类来识别故障类型。所提出的保护结构简单且无需设置，无需故障极选择元件和分类阈值。 Kun-Liu-Long LCC-VSC HVDC RTDS 系统的验证证明了该方法在不同条件下识别各种故障的有效性，包括故障类型、位置、电阻和信噪比。值得注意的是，它对故障阻抗 (600 Ω) 和噪声干扰 (20 dB) 仍然具有鲁棒性。