Field Validation of a Local, Traveling-Wave, Fault Detection Method for DC Microgrids

This paper proposes and validates a near realtime fault detection method using Traveling Waves (TWs) for DC microgrids. The method can be executed on low-cost embedded devices. Local positive pole voltage measurements are obtained at a high-sampling rate of 1 MHz, and a second-order high-pass filter is used to detect high-frequency transients on such time-series. A fault emulation hardware is assembled on a real DC microgrid to validate the performance of the method. A Texas Instrument Digital Signal Processor (DSP) device is mounted onto a custom signal-conditioning board. When a TW is detected, the DSP is capable of recording positive and negative pole voltages and positive pole current around the TW arrival time. Results show that the DSP's recording capabilities are similar to commercial oscilloscopes. This method can provide an accurate TW detection on DC microgrids in less than 15 microseconds.