Battery Insulation resistance Caluculation [Software code ]

[janybasha]

Hello Everyone

I have to develop insulation resistor value for our battery 350V
I have seen in online so many Caluculation for insulation resistor, but not sure how to develop a Embedded software code using this caluculation

my question, can you explian me please, how to develop software and hardware to find the Insulation resistor for battery 350V

Thank you
Greetings
Janybasha

 

[Alec_t]

Welcome to EP!
Insulation between the battery and what?
Do you have any programming skills, or electronics experience?
Is this a school/college assignment/project?
350V can easily KILL you!! You shouldn't be messing with it if you have to ask basic questions such as in this thread.

 

[janybasha]

Welcome to EP!
Insulation between the battery and what?
Do you have any programming skills, or electronics experience?
Is this a school/college assignment/project?
350V can easily KILL you!! You shouldn't be messing with it if you have to ask basic questions such as in this thread.

Hey Alec_t,
I want to caluculate Insulation of the Battery (may be between Battery V+ and V- or Ground)
Yes i do have 2 years of experince in programming software and I finished my Master's in Electronics and Electrical Engineering
It is one of my task in a big automotive Project
for now i have 24V battery where i can make my test and develop software but later on it will be used in Electric cars with 350V battery
I am reading already some information in online but i want to have experience transfer from someone who already developed it or who can give me more knowledge about it
Thanks for your help

 

[Alec_t]

I want to caluculate Insulation of the Battery (may be between Battery V+ and V- or Ground)

The impedance between battery V+ and V- is extremely low, i.e there is no insulation.

 

[janybasha]

The impedance between battery V+ and V- is extremely low, i.e there is no insulation.

Thanks for your message
Yes so I can measure insulation between V+ and ground and insulation between V- and ground?
Do you know any mathematical calculations how to measure this insulation?
Thanks for your reply

 

[Bluejets]

Assume it's the circuit itself you need to test.
Usual method to measure insulation resistance anywhere is a megger without any battery installed or power connected in the tested circuit.
Naturally any electronics installed have to be taken into account and protected if necessary during any testing.

Voltage setting on the megger depending on supply level.
Lowest setting on mine is 250v, then 500v then 1000v.
Mine uses a combination elcb test but same,same.

A little unclear just exactly what you are trying to do.
If it's the battery itself in a metal housing, surely measure any leakage current with respect to negative or positive terminals...??

 

[(*steve*)]

Do you know any mathematical calculations how to measure this insulation?

R = V/I

 

[janybasha]

Assume it's the circuit itself you need to test.
Usual method to measure insulation resistance anywhere is a megger without any battery installed or power connected in the tested circuit.
Naturally any electronics installed have to be taken into account and protected if necessary during any testing.

Voltage setting on the megger depending on supply level.
Lowest setting on mine is 250v, then 500v then 1000v.
Mine uses a combination elcb test but same,same.

A little unclear just exactly what you are trying to do.
If it's the battery itself in a metal housing, surely measure any leakage current with respect to negative or positive terminals...??

Hello Bluejets,
Yes, i saw this megger test devices [there is also fluke], we have also bought megger device to test
I give an Example , we have E-cars battery 350V and i measure Insulation resistance with megger so i got 1Mohms [just like by connecting megger to battery after pressing test button on it], so my task is to do this measurement continuously like all the time measurement insulation resistence[while car is driving] well i can not keep this megger device connecting to battery and display on the drive seat...so i have to develop software that can measure the insulation resistence and send the resistence to controller [1Mohm may be after a 5 years 5mohms] so basically i have to send this value to battery management controller to decide if the battery is running good without any current leakages.. yes for your question battery itself in a metal housing
thank you for your help

 

[Bluejets]

I don't see any point in measuring with a megger when power is connected in fact it may even damage the meter or, as I mentioned previously, any electronics on board.
Have no idea where the leakage could come from.
If the battery is installed in the vehicle as say negative ground, how would you intend to differentiate between whatever is normal current draw and leakage..??
Bit of a furphy if you ask me.

 

[BobK]

Are you trying to measure the self discharge rate of the battery? What you are saying makes no sense.

You cannot put a megger across the battery terminals and get any meaningful results.

Bob

 

[janybasha]

Hey Bluejets,
can you read this pdf, Automotive High-Voltage and Isolation Leakage Measurements Reference Design
http://www.ti.com/lit/ug/tidudj6/tidudj6.pdf
and give me your feedback
Thank you for your help

 

[BobK]

So after skimming the PDF you linked, I take it you have been saying "Insulation" when you mean "Isolation". No wonder no one knew what you were talking about.

For the rest of the forum: Apparently EV high voltage systems are isolated from the chassis. He is trying to measure the resistance from either HV battery terminal to chassis ground, which should be isolated.

Bob

 

[hevans1944]

... He is trying to measure the resistance from either HV battery terminal to chassis ground, which should be isolated.

AND the linked PDF file shows exactly how to make the required isolation resistance measurements, if you read it carefully all the way to end!

Wow! All this confusion has been promulgated by someone who is perhaps English challenged and has a "Master's in Electronic and Electrical Engineering!" I wonder if you can get fries with that? Oh, wait! I don't see any experience to go along with those qualifications.

As for software experience, two years of rolling code doesn't count for anything in the real world, except maybe you might have learned how to avoid syntactical errors in whatever programming language you used. However, your first line of code is already obsolete by the time the last line is written. Yes, things do change that fast (or faster).

I suppose confusion is to be expected when misspellings occur right up front in the title of this thread... or is caluculation a real word? Possibly some sort of degenerative disease or a variation of a migraine headache? Or maybe its an arcane term from the practice of astrology as in, "when the Moon is in the Seventh House (occurs twice a day) and Jupiter is in calucalation with Mars (happens fairly often, or so I am informed)..." but WTF does software have anything to do with it?

 

[janybasha]

I am really sorry for my bad English and misunderstanding
I am sorry
I closed this thread
Thanks for your messages

 

[Bluejets]

mmmm...yes, well I sort of hinted at leakage earlier and was thinking along the lines of lem systems used in hospital operating systems.
Although similar in requirement, a little different in application.
Seems furphy may have been closer to the truth than I imagined.

 

[(*steve*)]

Oh, wait! I don't see any experience to go along with those qualifications.

This observation may not apply to @janybasha but I have made it on my many trips to India that there are a vast number of people with masters degrees and higher who don't have any practical experience. The issue is that there is a larger opportunity for education than there is for gaining practical experience. It gets to the ridiculous level where employers like KFC (and this is an actual example) are able to use this level of educational achievement to filter applicants for positions that *actually* involve serving fries.

In most cases these people are doing the best they can to climb the socioeconomic ladder, and for that I have a great deal of sympathy.

Whilst we might get quite annoyed at people who demonstrate a lack of experience, I think it is worth tempering this with a realisation that practical experience itself may be the hardest thing to obtain in some places.

 

[hevans1944]

... I think it is worth tempering this with a realisation that practical experience itself may be the hardest thing to obtain in some places.

I know that it was difficult for me, first as a pre-teen and later as a teen-ager, to gain any creds of practical experience, no matter how much hobby experience I had accumulated. There was no social media available in which to exchange ideas when I was growing up.This situation didn't really change until after I enlisted in the U.S.Air Force for a four-year term of enlistment in May 1963.

I chose not to make the Air Force my career, but it was still not easy finding a job afterward. I talked my way into a good entry-level technician job, after meeting with my future boss and taking a written exam he had prepared for all the job candidates he interviewed. Apparently he was impressed with my completing his questions during his lunch hour, instead of my taking them home to complete on the "honor system" without outside help from anyone. I spent the next twelve years working for him and his successor full-time while pursuing a Bachelor of Electrical Engineering degree part-time. It was a great way to launch an electrical engineering career.

So, I do appreciate how difficult, if not impossible, it may be for @janybasha to obtain any real-world experience to round out his education. But at least he appears to be trying, perhaps just not in the most appropriate forum. Electronics Point is not a place where electronics enthusiasts come to get educated, per se. It is a collection of peer-to-peer forums where we can exchange ideas, problems we have encountered, and solutions we have found for those problems. Any education that results is a byproduct of the dialogs in which we engage. EP is also a good place to practice your mastery of technical English.