Project on magnetic energy harvesters (MEH), sensu stricto monitoring of transformers using MEH-power wireless sensors

Question

Dear Everyone, 
 I am currently working on my postgraduate project, focusing on the design of a free-standing magnetic energy harvester (MEH) intended to power wireless sensors. I find myself facing a hurdle due to my limited experience with transformers. Therefore, I am reaching out to seek insights and tips from those with expertise in this area. 
 In addition to monitoring the partial discharge (PD), I am curious to know what other critical conditions would be beneficial to monitor in order to assess the overall 'health' of the transformer using these wireless sensors. 
 Thank you in advance for your time and assistance. 
 Best Regards, 
 Jona

AJJewsbury · Accepted Answer

What sort of transformers are you thinking of? They can vary between huge 50Hz things (as used in the public supply) to small 50Hz ones traditionally used in items of equipment or very small high frequency AF/RF or HF power conversion ones? 
 If its the large public-supply kind of thing, I would suspect the first parameter to measure would be temperature. (Although I'm not sure how kind such an environment would be for wireless comms...) 
 - Andy.

mapj1 · Answer

If you can explain what you do k now about transformers and what you think you need to but dont, it should be possible to fill in some gaps ;-) In the meantime some general thoughts. 
 You do not say if the mechanical stimulus to be harvested is intermittent (the extreme of this would be the ones in the 
 q inati c switches) or more like a continuous system from say engine vibrations or wind flapping something. 
 In all but the highest voltage systems or the most mission critical cases, a partial discharge test is unlikey to be helpful oe required in an energy harvester. 
 The most common fault is a shorted turn, and at manufacture that can be detected by an inductance / Q-meter test. During use that will manifest as a catestrophic losss of power. 
 I imagine you will be looking at sub-watt power levels, so the main thing will to be not to waste energy with more load than is required, so self test needs to be simple. 
 Also the design of a transformer for pulses or indeterminate frequencies or power levels is not the same as nrmal 50Hz power transformer design - devices can be much smaller if heating is short term adiabatic rather than steady state. 
 
 Mike.

Jona Schubert · Answer

I had the larger ones in mind, so thank you for your input regarding temperature sensors.

Project on magnetic energy harvesters (MEH), sensu stricto monitoring of transformers using MEH-power wireless sensors

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