3 Application Overview

The application demonstrator showcases the phase sequence detection, phase loss detection, and RMS voltage measurement on an emulated three-phase AC supply, using the AVR128DA48 microcontroller.

The demo uses an emulated three-phase AC supply to showcase the essential features of the application. To emulate the AC power supply, three Mikroelektronika waveform clicks are used in the application. The waveform click generates sinusoidal signal with desired amplitude, phase and frequency. The application configures the waveform clicks to generate three 3.3V sinusoidal signal with 50/60 Hz and 120° phase difference to substitute the AC supply. Additionally, to showcase the various faults the waveform clicks can be reconfigured by the application in the run-time to change the output signal.

In the application, the data visualizer tool is used to interact with the application firmware through a UART interface. The data visualizer is used to monitor and report the live status of phase reversal, phase loss, and RMS voltage of the signal. It is also used to send the emulator commands to replicate the various faults by waveform clicks.

Figure 3.1 showcases the block diagram of the application demo used.

Figure 3-1. Application Overview

To select between the 50 Hz and the 60 Hz operating mode, the on-board curiosity nano switch is used. The system stays in Frequency Selection mode for 10 seconds after power-up. By default, the system starts with 50 Hz frequency and it can be changed by pressing the switch after the board is powered up. The selection change can be viewed on the dashboard window of the data visualizer.

The application continuously monitors the three-phase power supply for phase reversal and phase loss faults. The result of phase sequence, phase loss, and RMS voltage level of the three-phase signal are continuously updated on the dashboard window.

Upon receiving the user inputs to demonstrate phase loss and phase reversal faults from the dashboard, the application updates the configurations of waveform clicks. Thereby, the three-phase signal with desired fault condition is generated by the waveform clicks.

Also, the application restores the fault conditions, when an appropriate command is received from the dashboard to recover from the fault condition.