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AC voltage and current monitoring up to 1000 volt by raspberry with interfacing Arduino among them  

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navid.1992
(@navid-1992)
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Joined: 5 days ago
Posts: 4
2020-10-17 7:52 am  

I have one voltage probe(up to 1000 V) and one current probe(up to 1000 A). I have to design a system composed by voltage probe and ragowski coil sensor (measuring current) with Aurdino. and then the output of Arduino will connect to the Raspberry Pi for power monitoring.



Can someone tell me that what material I should provide for Arduino to read voltage and current which have been measured with probes. and how is it possible to make data to be readable for Raspberry?

 


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DroneBot Workshop
(@dronebot-workshop)
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Joined: 1 year ago
Posts: 627
2020-10-17 1:31 pm  

@navid-1992

When I read this I thought you might be gifted with ESP, as I'm currently creating a video and article about measuring AC and DC voltage and current using an Arduino!  

There are a number of ways you could pass the data from the Arduino to the Raspberry Pi, my impulse would be to use I2C. Set the Arduino up as an I2C slave and the Pi as the master. Then the Pi can query the Arduino for the voltage and current readings.

Blatant self-promotion warning! I have two videos that might assist you with that part:

This one shows you how to turn an Arduino into an I2C slave device.

And this one shows you how to interface a 5-volt Arduino with a 3.3-volt Raspberry Pi via I2C.

Hope some of this is useful!

😎

Bill

"Never trust a computer you can’t throw out a window." — Steve Wozniak


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navid.1992
(@navid-1992)
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Joined: 5 days ago
Posts: 4
2020-10-18 9:33 am  

dear Bill

thanks for your kindly response. I was wondering that you could answer one more question to me.

my ragowski coil current sensor.

as you know the ragowski coil output signal is in mV. So, I should connect the output of this sensor to the digital pins of arduino or analag output( A0- A3) ??? for seeing the metered current on arduino software.

best regards


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DroneBot Workshop
(@dronebot-workshop)
Workshop Guru Admin
Joined: 1 year ago
Posts: 627
2020-10-18 10:46 am  

@navid-1992

It's definitely an analog input, however, a signal in the millivolt level would only register in the lower range of the A/D convertor and would approach the noise floor, so it wouldn't produce a useful reading at lower currents.  But if the currents you are measuring are over 100 amps or so it would probably work.

The Rogowski coil sensor I just read about on the Arduino forum produces an output of .404 mV/A, so a 100 amp current would produce a 40.4 mV output. Unless I did the math wrong that equates to a reading of about 10 out of 1024 on the Arduino A/D converter, assuming a 5-volt reference.

Lowering the Arduinos analog reference voltage (established on the AREF pin) would increase the range slightly, and you could use a low-noise amplifier, like an instrumentation amplifier, to boost the signal to a reasonable level. This would allow you to measure lower currents.

A microcontroller like the ESP32 with a 14-bit A/D and a 3.3-volt reference would give you a bit more range.  Not sure if it would be enough for your purposes, but as I don't know what your intention is I really can't say.

😎

Bill

 

"Never trust a computer you can’t throw out a window." — Steve Wozniak


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DroneBot Workshop
(@dronebot-workshop)
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Joined: 1 year ago
Posts: 627
2020-10-18 11:05 am  

One other question - are you only using the Arduino for its A/D converter, or does it have an additional function?

If your intent is to use the Arduino just to get analog data into the Raspberry Pi a better (and much simpler) arrangement would be to us an actual A/D converter, like the ADS1115, which has much higher precision. The ADS1115 also has a built-in programmable gain amplifier, so it would respond well to the low-level signals from your coil.

Adafruit has an article that might help you.

😎

Bill

 

"Never trust a computer you can’t throw out a window." — Steve Wozniak


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navid.1992
(@navid-1992)
New Member
Joined: 5 days ago
Posts: 4
2020-10-18 11:09 am  

dear Bill

 if I want to use another for metering the current with Arduino.

what would be your suggestion? my current range is 0-1000 Amper

 

best regards.


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navid.1992
(@navid-1992)
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Posts: 4
2020-10-18 12:36 pm  

Sorry for my interruption,

the aim of using arduino is acting as interface board for transferring the metered high voltage and current to Raspberry for smart monitoring of electrical network. this is the my first step of master degree thesis and in the second step, i should write a program in python for smart monitoring of power network.

thanks Bill for helping me 🙂

 


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