Power Quality Analyzer

• 3-phase voltage, current, frequency, measurement
• active, reactive, apparent power, power factor
• neutral current
• harmonics analysis up to 50th order
• quality - swell, dip, interruption, transient/over voltage, inrush current, unbalance rate
• real-time operation
• USB communication interface

• installation of esp-idf development environment

$ mkdir ~/esp
$ cd ~/esp
$ git clone -b v5.5.1 --recursive https://github.com/espressif/esp-idf.git
$ cd esp-idf
$ ./install.sh esp32s3

• pqa project configuration

$ cd ~/projects.local/elektro/pq-anal/fw/pqa
$ . ~/esp/esp-idf/export.sh
$ vim main/idf_component.yml
$ cat main/idf_component.yml
## IDF Component Manager Manifest File
dependencies:
...
espressif/esp-dsp: '*'
$ idf.menuconfig

• Serial flasher config —> Flash size (8MB)
• Component config —> ESP PSRAM —> [*] Support for external, SPI-connected RAM
• —> SPI RAM Config —> Mode (QUAD/OCT) of SPI RAM chip in use (Octal Mode PSRAM)
• —> SPI RAM Config —> SPI RAM access method (Make RAM allocatable using malloc() as well)
• —> SPI RAM Config —> (1024) Maximum malloc size, in bytes, to always put in internal memory
• —> SPI RAM Config —> Allow .bss segment placed in external memory
• Component config —> ESP System Settings —> CPU frequency (160MHz)
• Component config —> LWIP —> SNTP —> (2) Maximum number of NTP servers
• Component config —> DSP Library —> DSP Optimization (ANSI C)
• Component config —> DSP Library —> Maximum FFT length (4096)

For three-phase balanced system, the sum of instantaneous values of phase voltages (as well as currents) is zero: $$v_{L1} + v_{L2} + v_{L3} = i_{L1} + i_{L2} + i_{L3} = 0$$ In such case also $$u_{N1} = u_{N2} = 0$$ and $$v_1 = v_{L1}\frac{R_{12}}{R_{11} + R_{12}}$$