The wide application of power electronic component in power system with renewable energy sources has changed the fault characteristics of conventional power system, resulting in the performance degradation of conventional protection, and even the risk of maloperation and rejection. This brings challenges to the security and stability of the power grid. Therefore, in order to solve these problems, a novel principle of pilot protection based on structural similarity and square error method is proposed. The structural similarity criterion makes use of the difference of fault characteristics between renewable sources and synchronous generators to identify internal faults, while the square error auxiliary criterion is used to solve abnormal calculation of the existing similarity based protection. The detailed model of grid-connected renewable energy power plant is built in Real Time Digital Simulator (RTDS) and the proposed protection algorithm is solidified in the industrial protection device. The effectiveness of the proposed principle is verified by hardware-in-loop dynamic simulation experiments. Compared with conventional differential protection, the proposed protection shows excellent performance in speed and reliability during various faults. In addition, a field short-circuit test is carried out in a real wind farm to verify the effectiveness of the proposed protection scheme. It is proved that this proposed method has the prospect for industrial application.

中文翻译：

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基于结构相似性的可再生输电线路先导保护

电力电子元件在可再生能源电力系统中的广泛应用，改变了常规电力系统的故障特性，导致常规保护性能下降，甚至存在误动作和拒收风险。这给电网的安全稳定带来了挑战。因此，为了解决这些问题，提出了一种基于结构相似性和平方误差法的导频保护新原理。结构相似性判据利用可再生能源与同步发电机之间故障特征的差异来识别内部故障，而平方误差辅助判据则用于解决现有基于相似性的保护计算异常。在实时数字模拟器（RTDS）中建立并网可再生能源发电厂的详细模型，并将提出的保护算法固化在工业保护装置中。硬件在环动态仿真实验验证了所提原理的有效性。与传统的差动保护相比，所提出的保护在各种故障期间表现出优异的速度和可靠性性能。此外，在真实风电场中进行了现场短路测试，以验证所提出的保护方案的有效性。证明该方法具有工业应用前景。硬件在环动态仿真实验验证了所提原理的有效性。与传统的差动保护相比，所提出的保护在各种故障期间表现出优异的速度和可靠性性能。此外，在真实风电场中进行了现场短路测试，以验证所提出的保护方案的有效性。证明该方法具有工业应用前景。硬件在环动态仿真实验验证了所提原理的有效性。与传统的差动保护相比，所提出的保护在各种故障期间表现出优异的速度和可靠性性能。此外，在真实风电场中进行了现场短路测试，以验证所提出的保护方案的有效性。证明该方法具有工业应用前景。