This paper presents a testbed for real-time testing of Traveling-Wave Fault Locators (TWFLs). A Field Programmable Gate Array (FPGA) is used as the main hardware platform for conducting the real-time simulation. To accurately reproduce fault-launched travelling waves, the simulated power system is executed at a 500 ns time-step. The fault locating device is the SEL-T400L relay with a sampling rate capability of 1 MHz. The simulated grid is composed of constant parameter (CP) transmission lines (TLs). The paper presents the capabilities and limitations of such an approach and assesses the suitability of the line model for testing TWFL. Firstly, off-line analyses and validation are performed using EMTP. It is found that the CP line model can be incorporated in the double-ended TWFL testing setups. For the single-ended TWFL testing, it is shown that the CP line model can introduce false transients due to ground propagation mode which can affect testing accuracy. Secondly, real-time experimental simulations are done to elaborate the importance of sub-microsecond time-steps for testing of TWFL.

中文翻译：

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基于恒定参数行的 TWFL 实时测试台的评估

本文提出了一个用于实时测试行波故障定位器 (TWFL) 的测试平台。现场可编程门阵列（FPGA）被用作进行实时仿真的主要硬件平台。为了准确再现故障发射的行波，模拟电力系统以 500 ns 的时间步长执行。故障定位设备是 SEL-T400L 继电器，采样率能力为 1 MHz。模拟网格由恒定参数 (CP) 传输线 (TL) 组成。该论文介绍了这种方法的能力和局限性，并评估了用于测试 TWFL 的线路模型的适用性。首先，使用 EMTP 进行离线分析和验证。发现 CP 线模型可以合并到双端 TWFL 测试设置中。对于单端 TWFL 测试，结果表明，CP 线模型会由于地面传播模式而引入虚假瞬变，从而影响测试精度。其次，进行实时实验模拟以阐述亚微秒时间步长对 TWFL 测试的重要性。