How to implement an Insulation Measurement [Chassis to High Voltage Battery] in PCB

Discussion in 'Automotive Electronics' started by niksuse, Jul 17, 2017.

  1. niksuse

    Thread Starter New Member

    Jul 17, 2017
    Hi, I am designing a battery pack for Automotive application. One of the requirement of high voltage battery pack is to have insulation measurement between high voltage battery and vehicle chassis. This measurement will ensure that current / voltage is not leaking to the chassis from vehicle and ensures safety. I need to implement it in a PCB [although not sure as I don't know what is the general way of doing this]. Ultimately I need to know the value in digital form [ohm per volt] to forward that data to vehicle control. This thing is probably called Megger [its a company name also] but they are separate device so I need to know how I can implement it in digital form in my PCB.

    Any help is highly appreciated.

    Thanks and Regards
  2. tcmtech

    Distinguished Member

    Nov 4, 2013
    Do you really need it or do you just want it to say you have it?

    Ohm's law is where I would start but if it's a totally isolated system the only way you can take a valid reading of leakage current is to have it unisolated at one end in order to complete a circuit for that leakage to occur.
  3. #12


    Nov 30, 2010
    The conductivity between two unconnected systems is by definition, zero.
    However, you said you need to send data to vehicle control, therefore, there is a conductivity at some voltage and/or frequency. This could be as easy as reading the datasheet for the opto-coupler you use to send data and it might be as complicated as having a PCB drag a chain on the road and apply a Megger to the chain and the vehicle control module.

    You give us little to work with.
  4. dl324

    AAC Fanatic!

    Mar 30, 2015
    Welcome to AAC!
    Google "hipot test". Don't know what your specific needs are. Hipot tests can be done at a few hundred volts to a few thousand volts.

    I sometimes had to work at the hipot test station for power supplies at a computer manufacturer. When things fail, there's sometimes a lot of smoke. Our tester had a dial so we could ramp the voltage slowly (sort of).