Hello! I have a thesis problem. My thesis is about detecting and notifying electrical pilferages on residential household. My device is connected to the line side so thats tha are of where i can only detect pilferage. I have a testing envirwhere there are legal and illegal consumers. The theory is, I want to generate harmful frequencies to the illegal consumers once a certain threshold is met. Right now i can set it at 100Hz that ultimately stops the illegal consumer by tripping their connections and possibly damaging their equipment. However, I’m stuck on how can i protect the legal consumers from the harmful frequency without tripping their line. So i tried numerous protective devices including;
1. Another VFD. where I set the output frequency back to 60hz while its being fed with 100hz. I tried this with a motor load but when i inserted it to the actual device, the resistor of the PZEM004T burnt.
2. Noise filter. Didn’t work at all because noise and frequency are different things
3. Tried looking for a frequency filter but no luck
4. Want to try a frequency converter but not sure if i have enough resources to recover if it didnt work.

Thanks everyone! I hope someone can help me with this.

 

I do not see any way for this to work.

 

I do not see any way for this to work.

is the frequency converter worth a shot? Or any other alternatives to read the power consumption other than the PZEM?

 

Hi,

Sounds to me like you would have to have good control over each and every house power feed line. That could take some royal retrofitting.

 

Hi,
probably, you can use series LC tank for legal consumers. Only 60Hz will pass the tank. However, such a tank is a bulky device

 

D

Hi,
probably, you can use series LC tank for legal consumers. Only 60Hz will pass the tank. However, such a tank is a bulky device

Thank you so much for this! are these commercially available or am i going to be the who will create this?

 

Hi,

Sounds to me like you would have to have good control over each and every house power feed line. That could take some royal retrofitting.

hopefully will not resort to fabricating my own or hopefully I can simulate this using multisim

 

Synchronous and induction motors are not that common in a domestic environment. Most domestic appliances would work quite happily at 100Hz, especially anything with a switched mode supply (which is most things these days).

 

Synchronous and induction motors are not that common in a domestic environment. Most domestic appliances would work quite happily at 100Hz, especially anything with a switched mode supply (which is most things these days).

I tried the vfd on a fan. When it hit 100Hz it stopped turning and just creates rattling sounds but not so much as destroy the appliance. When I reset it at 60Hz it goes back to normal. Lights are not affected by this in anyway as they are resistive loads and therefore not affected by frequency. Only have troubles on how will i be able to protect legal consumers from the frequency.

 

I never saw those LC tanks in a shop.
It seems, DIY only. I saw a link , where the series LC tank was proposed to convert so called "modified sine wave" from an UPS to a really sine wave. They made inductance with air gap to achieve the required inductance, as the tank is to be tuned to 60Hz. The capacitor is to be rated at 800-1000VAC at least, if mains voltage is 230V

 

Have you considered the legality of deliberately destroying someone else's property?