DC system has come a long way to shift the direction of power transmission in future. With respect to that, the protection is still one of the hot topics that need to be addressed, particularly the dc fault detection method. This paper presents methods to robustly differentiate between load change and dc fault in a two terminal dc system connected to passive load. In the first method, wavelet transform is used to determine the wavelet coefficient for the system dc line current. The performance of wavelet transform is compared with the rate of change of current (di/dt) method. Details regarding synchronous reference frame dq current controller at source terminal, root mean square method controller at load terminal are discussed. Simulation studies are carried out on MATLAB/Simulink model and the corresponding steady state, load change, and fault studies results are presented. Experimental validation of wavelet fault detection method is performed on the developed laboratory dc grid setup interfaced to dSPACE 1103 controller through MATLAB real time toolbox.

中文翻译：

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基于VSC的直流电网系统故障识别的实验验证


直流系统在改变未来电力传输方向方面已经取得了长足的进步。就此而言，保护仍然是需要解决的热点话题之一，特别是直流故障检测方法。本文提出了在连接到无源负载的两端直流系统中稳健地区分负载变化和直流故障的方法。在第一种方法中，使用小波变换来确定系统直流线路电流的小波系数。将小波变换的性能与电流变化率(di/dt)方法进行比较。详细讨论了源端同步参考系dq电流控制器、负载端均方根法控制器。在MATLAB/Simulink模型上进行仿真研究，给出相应的稳态、负载变化和故障研究结果。小波故障检测方法的实验验证是在通过 MATLAB 实时工具箱连接到 dSPACE 1103 控制器的已开发实验室直流电网设置上进行的。