Open-Source Heterogeneous Constrained Edge-Computing Platform For Smart Grid Measurements

This article presents a low-cost, open-source, heterogeneous, resource-constrained hardware platform called "Parallella" as a measurement device for edge-computing applications research in smart grid. The unique hardware architecture of the Parallella provides a multitude of edge-computing resources in the form of a Zynq SoC (dual-core ARM + FPGA) and a 16-core co-processor called Epiphany. A multifunctional intelligent electronic device (IED) design is demonstrated to showcase the capabilities of the platform. A custom I/O board has been developed for the desktop and embedded versions of Parallella, which can be interfaced with external daughter boards and peripherals for measurements. One such daughter board is an analog sensing board, which can measure voltages of all the three phases and four line currents using a 16-bit synchronous ADC set at 32 kHz. The ADC samples are synchronized to the PPS time clock of a GPS unit for providing global time reference. These captured seven-channel raw waveform data are sent to a cloud server over a bandwidth-limited communication channel using a custom anomaly-aware data compression algorithm implemented on the ARM. A phasor measurement algorithm using the Teager energy operator (TEO) is implemented on the field-programmable gate array (FPGA). A parallel power quality (PQ) measurement algorithm is implemented on the Epiphany. The obtained measurements are found to be comparable to a commercial power analyzer.