transformer drift characteristics?

transformer drift

Hi, Its been quite a while since I posted here..

Can anyone help me in my current problem, I have an electric power meter, after calibration (3 months) it failed... it uses ADE7755..

I will be doing some reliability testing on it in a couple of weeks and I need to know more about transformer characteristic vs. heat and vibration... does it affect the transformer and how it affects it.. and how to check it..

I will do before and after testing... to prove my concept... but I need to support it with documents..

drift characteristics

It's not easy to give less information.

You may be talking of a current transformer utilized in your instrument. Generally, it should be expected more reliable and stable than most other components in your design, if it's operated according to the specifications. Also drift is clearly different from failure, so what are you asking actually?

transformers drift

No, not the current transformer... its the power transformer.. The ADE7755 is connected in the primary windings (just like a voltage divider) the channel 2 (voltage input) is also connected in the Line and neutral is connected to the GND of the ADE7755.. this makes the transformer to have an effect on the voltage channel ... If the resistance of the transformer changes the calibration also changes... since its connected to the windings..

so my question.. does a transformer can change resistance over time due to temperature or vibration??

current transformer drift

The ADE7755 is connected in the primary windings

Click to expand...

What do you mean?

does a transformer can change resistance over time due to temperature or vibration??

Click to expand...

No.

voltage transformer drift

The power supply of the ADE7755 is from the primary windings..

primary windings, has 2 parts..the main and a sort of a center tapped like connection... but the output is around 10Vac only..

passed through a half wave rectifier then a regulator (linear).. the output connects to the DVDD and AVDD of the ade7755..

when the primary windings is connected. the resistance (total) of the v2 input channel is affected.. so if there is a change in the transformer characteristics it will affect the accuracy of the V2 input... that is what I think..

--------So if the resistance doesn't change with respect to prolonged exposure to temp and vibration... what could possibly changed to affect the meter reading.. is it the ADE7755 input characteristics??

--- main problem is .. today we calibrate the meters... then after a few months the calibration will be drifted.. but the meters can be re-calibrated....




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