Tan Delta Webinar Advanced

After the first issue of Webinar on Tan Delta, this is the second issue. Here we show more examples, on Trafo but also Rotary Machines and Cables. We discuss UST and GST Modes and in the the end we briefly talk about comparison between Partial Discharge and Tan Delta and Polarisation Index and Tan Delta

[@lexvanheel]

Thanks Andrej for this great explanation. These 3 videos are an excellent explanation of tan-delta (PF/DF) testing!

[@sheppo17]

Dear Lex, thank you so much :) I really apreciate these comments :)

[@mhdsdmelhefnawy]

Thanks for sharing these information with us!
It is very helpful.

[@sheppo17]

You are most welcome Mohammad ! Hope you enjoyed it and learned something.

[@Balakrishnan-cc2ic]

Great explanation. very useful for beginners.

[@sheppo17]

Thank you Balakrishnan

[@athlos1]

Very nice webinar, thanks for sharing

[@sheppo17]

Glad you enjoyed it!

[@harinath009]

sir im working as executive engineer in APTRANSCO, ANDHRA PRADESH, INDIA USING ISA TDX 5000 FOR TANDELTA MEASUREMENTS OF EHV BUSHINGS, POWER TRANSFORMERS, CTS, PTS, BREAKERS VERY OFTEN
1) IN DEMO VIDEO THE CONSTANT K AND WHILE TESTING CAPACITANCE AND TANDELTA IN KIT THERE IS A CONSTANT K BOTH WERE SAME OR DIFFERENT?
2)WITHOUT SELECTION OF K BY ADDING NEW TEST POINT IN ISA TDX 5000 KIT THE TANDELTA VALUE MEASURED IS AT 20DEG CENT OR AMBIENT TEMP?

[@sheppo17]

Dear Harinadh !
The constant K is the same for Tan Delta and Capacitance mesurement. And about question 2 - it is not measured at ambient temp because TDX does not know what is the present ambient temperature. Hope this helps and excuses for late reply.

[@lefthanded1984]

Hi Andrej, can I know whether this tan delta is based on schering bridge measurement?

[@sheppo17]

Hi Sharin ! Yes, but it is automatic

[@sheppo17]

There is one ultra accurate capacitor inside and two very accurate resistors, all with very small temperature drift

[@926prasenjit]

you havent mentioned about 'tip up' value of tan delta sir ?? our testing agency give reports in terms of tip up or difference in tan delta at higher voltage to lower voltage level. Kindly explain its significance too sir.

[@sheppo17]

Dear PV, you have correctly noted that I have not commented that here. Tip up test and some time also tip down test is executed. It is standard when testing rotary machines, and with trafo it is not always required. Having said that different countries have different standard which is why I have not explicitly mentioned that here, since I would need to cover all the standards. In general if TD value on Trafo had increased significantly or the value is high, we can perform this test and we evaluate the curve, which should not change the value too much. For example we do not want to see high value for low voltage, that then decreases and continues to grow afterwards.

[@926prasenjit]

@@sheppo17 Dear sir, thanx a lot for the reply. We get 600MW turbogenerator stator tested for tan delta at 2kV, 4kV, 6kV, 8kV, 10kV, 12kV and difference in tan delta value at 12kV and 2kV is considered as acceptance norm for tan delta by our testing agency as per IEEE62.2 . The difference is quite less but tan delta is just greater than 1% in case of turbogenerators. Is tan delta always higher in case of rotating machines ?

[@sheppo17]

@@926prasenjit yes, almost always rotary machines have higher values of tan delta

[@926prasenjit]

@@sheppo17 sir, if you have time , please make video on tan delta test values of rotating machines of high rating such as turbogenerators, hydro power generators. i can share test data with you if you want.

[@lefthanded1984]

Can u share link for next webinar?

[@sheppo17]

Hi Sharin !
This is it - it is for Partial Discharge. We will have one more on Tan Delta but on 7. May.
Please register for Introduction to Partial Discharge test diagnostics on HV cables on Apr 30, 2020 2:30 PM CEST at:
attendee.gotowebinar.com/register/5012824550515597838
After registering, you will receive a confirmation email containing information about joining the webinar.