Software apps and online services
This project is the development of an oscillogram to monitor the voltage amplitude and frequency on utility grid. If a disturbance occurs in the voltage, e.g., undervoltage or overvoltage, four cycles of the waveform will be stored during this disturbance. The main grid frequency considered is 60 Hz, and its sampling is done at 30720 Hz, resulting in a vector of 2048 points. These points are sent by serial communication to a PC with Linux (it can be Raspberry Pi, etc...) where a program (in C) receives the values and stores it in a.csv file, and can be reproduced later in MATLAB or Octave, for instance. On the microcontroller, there is an OLED LCD to show the monitoring information.
Example file content with waveform (dataloger_0.csv):
26, 5, 2019, 16, 12, 23, 0, -0.960
26 (day), 5 (month), 2019 (year), 16 (hour), 12 (minute), 23 (second), 0 (sample 0-2047), -0.960 (amplitude in p.u.)
Example file content with voltage amplitude and frequency
27, 5, 2019, 15, 33, 52, 125.94, 59.93 (dataloger_1.csv)
27 (day), 5 (month), 2019 (year), 15 (hour), 33 (minute), 52 (second), 125.94 (voltage magnitude), 59.93 (frequency).
To monitor the voltage parameters, a software phase locked loop was implemented in LaunchPad TI EK-TM4C1294XL conform Software Phase Locked Loop Design Using C2000 Microcontrollers for Single Phase Grid Connected Inverter.