Problem with Rogowski Coil and ESP32

[ajakmyslisz]

Hello,
In one of my projects I need to use Rogowski Coil but I have trouble with it. In datasheet (https://statics.cirrus.com/pubs/proDatasheet/CS5490_F3.pdf) I’ve found information about use of this coil to get measurments of AC Current and voltage.
In this datasheet on Page 16 AD 4.7 I’ve found information about settings of coil. I use function: CS5490::write(Page, Address,Value) to write on Page 16, Address 0, value = BIN, 0001 0000 0000 0010 0001 1010, HEX:10 021A
I tested this code many times with both register write and without it but every time I get same response:

Vac RMS: 236.35 [V] @ 49.99 Hz
Iac RMS: 0.0258 [A]
PF: 0.4204
Active power: 2.5540 W
Reactive power: 3.1723 VAR
Apparent power: 6.0758 VA

RMS seems ok, HZ too. From IacRMS I’ve got a lot of trash in low current but in PF value when I connect somehing to outlet - value drops to 0.1 when it should indicate around 0.9 - ~1.0.
After this other value cant be good and it returns VAR/VAC with fake values.

I tested this with CS5490_AC_Current_Gain_tuning_demo, my code with short configuration and reading value in loop with 2 seconds delay in contConv and haltConv where basic parameter is:

#define R_SHUNT_OHM 0.000416 // <- from datasheet of PA3202NL Rogowski Coil (https://pl.mouser.com/datasheet/2/336/plei_s_a0003555710_1-2281160.pdf) because at 50 HZ this coil have drop of 416uV/a
#define V_ALFA (1000.0/1689000.0) // Resistor partition ratio on V input: on CDB5490U 4 * 422kOhm + 1kOhm
#define SYS_GAIN 1.25
#define V_FS 0.6
#define V_FS_RMS_V 0.17676 // 250mVpp
#define V_MAX_RMS (V_FS_RMS_V/V_ALFA)
#define I_FS 0.6
#define I_FS_RMS_V 0.17676 // 250mVpp with GAIN 10x, otherwise with GAIN 50x 50mVpp --> 0.3535 Vrms
#define I_MAX_RMS_A (I_FS_RMS_V/R_SHUNT_OHM)
#define P_FS 0.36
#define P_COEFF ((V_MAX_RMS I_MAX_RMS_A) / (P_FS SYS_GAIN * SYS_GAIN))
#define SAMPLE_COUNT_DEFAULT 4000 // Number of sample used to compute the output low rate computation (with quartz 4.096MHz --> 1 measure/s).

Im stuck at this moment, earlier I used a resistance measure of current ant that solution did work properly but now I need to use a Rogowski coil which causes described problem.
Have you got any idea what could be wrong with this and how to overcome the problem?

[tiagolobao]

Hello!

Sorry for the late reply... tbh I don't have any valuable information anyway.
I was reviewing the software part and I looks like your configuration is ok.

Do you have any progress regarding it?

@MaurizioMalaspina made the Gain_Tuning_Demo and maybe could check something as well if available.

For now I'll make some research in this topic and if you have any news u can share here :)

[MaurizioMalaspina]

Hi Tiago, unfortunately I've no way to setup a test bench in order to experiment with a Rogowsky transducer at the moment. Sorry... Il Gio 30 Set 2021, 13:28 Tiago Lobão ***@***.***> ha scritto:

…

Hello! Sorry for the late reply... tbh I don't have any valuable information anyway. I was reviewing the software part and I looks like your configuration is ok. Do you have any progress regarding it? @MaurizioMalaspina <https://github.com/MaurizioMalaspina> made the Gain_Tuning_Demo and maybe could check something as well if available. For now I'll make some research in this topic and if you have any news u can share here :) — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#13 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AF6YPACJFRAFRA4OPQRRYW3UERCUNANCNFSM5DUIRTHA> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.