High frequency AC current measurement for induction heater

Using Arduino Project Guidance
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Greetings forum! I am continuing to develop my full bridge invertor for induction heating and my current goal is to achieve automatic current resonance control in my parallel LC contour. For this I am planning to use current sensor, installed in inductor power line. When changing PWM frequency I expect to detect AC current peak changes and according to that change operating frequency to be lower or higher.

For initial test I used ACS758 100A bidirectional version, ADS1115 adc and ESP32. Power source is 24V. Of course, I only got average measurement, which is 0A, as PWM frequency is around 53 kHz and adc's max sampling rate is 860. At least current sensor according to data sheet is capable to work with 120kHz current frequency. Below you can see few photos of current sensor output signal on oscilloscope.

Duty cycle 10%

IMG_20231016_180228
IMG_20231016_1802281920×1079 206 KB

Please, don't mind that there are two signals, just tested two outputs of ACS758 to see any difference between them.

Duty cycle 40%

IMG_20231016_182027
IMG_20231016_1820271920×1079 173 KB

I would like to know what is the best approach for my task to measure high frequency AC peak current? Are there any complete modules for that? Or should I build a custom solution? Maybe I can use something else to process signal from ACS758 and return a result to ESP32?

One of possible ideas, I believe, is to put current transformer onto inductor line. Then add diode rectifier, capacitor, resistor and measure DC current on it, which can be recalculated to AC mains value.

Thank you for reading!

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ADS1115 is far too slow. You need something capable of at least 100ksamples/sec. Preferably much faster than that and capable of continuous sampling.
Built in ESP32 ADC is 83kHz but still too slow. You need a faster ADC but I don't know an arduino board that has one fast enough. Could you build a peak detector and measure that instead?

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How do you plan to calibrate you measurement device if you find one?

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If you are building the inverter to do this can’t you measure current on the low frequency side ?
(I’d image on the HF side the current waveform would have a lot of harmonics as it drives a non linear load , making it
Pretty impossible .)
Or might be worth a google to see if /how others do it , or even finding a different method to detect resonance .

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