Welcome to EV

Ask for and share advice on using the PicoScope kit to fix Electric Vehicles
Post Reply
Steve Smith
Pico Staff Member
Pico Staff Member
Posts: 940
Joined: Sun Aug 25, 2013 7:22 am

Welcome to EV

Post by Steve Smith »

Following on from the success of the dedicated section on the forum “Heavy Duty and Off Highway” (thank you Mr. Martins) it seems more than applicable to introduce another new section for “Electric Vehicles” given the introduction of the Pico Electric Vehicle kit.

Please feel free to browse, digest, challenge and post anything EV related here where I am sure we can all add value and learn about this alternative power source

Moving on:
To say the automotive industry is going through a change is understatement akin to the epitaph inscribed on the headstone of the late comedian Spike Milligan which reads “I told you I was ill

I can remember joining this challenging profession in 1983 where the Master Technicians of the day were tasked with the introduction of mainstream engine management systems.

This was a time when a Maestro was a family hatchback, an Engine Analyzer was as big as a double wardrobe and “CAN” was something that contained a fizzy drink

I would often hear phrases from mentors claiming “cars are becoming too advanced” and “there will be nothing left for us to do now carburetors and points have gone

Roll on 37 years and the rumor mill is turning again with the rapid growth of Electric Vehicle sales and similar phrases being shared amongst the great and the good.

From my perspective, I cannot think of a better time to join our profession and embrace the opportunities that lie ahead. The role of the technician is more important now than it has ever been and continues to evolve in direct proportion to new technologies.

From Main Dealer to Aftermarket, Off Highway to Renewable Energy, electrification is here to stay and if you are not onboard, you will be left stranded.

Make no mistake, regardless of the power source (ICE or Electric Motor) vehicles/machines will continue to develop faults and will most certainly require maintenance.

Whilst EV’s utilize an amazing power source, the vehicle infrastructure presents new diagnostic opportunities such as charging errors, contactor failure, invertor malfunctions, insulation and bonding faults to name but a few! Couple these fault conditions to the usual ABS, Steering, Suspension and Network errors and…..“You’re gonna need a bigger boat” (to quote Chief Brody from the movie Jaws)

A number of manufacturers boast of “connected cars” with intelligent on-board self-diagnosing systems; early indications of such features confirm external verification is still required followed by rectification & confirmation of repair (Does this sound familiar?)

Whilst our profession may be changing, the rules remain the same; in order to maintain, diagnose and verify components efficiently, test equipment & measurement techniques must be applied and inevitably evolved

So, what now for PicoScope and where does this fit with EV & HV (high voltage) applications?

The ability to capture and correlate a multitude of signals to other events in real time regardless of their nature (e.g. voltage, current, pressure, sound or vibration etc.) becomes invaluable at any stage of maintenance or diagnosis regardless of the power source

Let’s take a look at a customer complaint of reduced range from a full EV vehicle with no fault codes or plug-in charging issues. Could there be a fault with the regenerative braking system?
Regen over-run v brake
Regen over-run v brake
Above we use PicoScope to correlate current flow to and from the HV battery with the accelerator pedal position sensor and brake pedal switch. Not only have we confirmed the regenerative braking feature to be functioning correctly, we have verified the difference between regenerative charging during over-run and braking. The conclusion here is that the system is functioning correctly and our customer expectation of battery range requires managing.

Moving on with EV applications, it should come as no surprise that a scope cannot do everything! Whilst PicoScope can measure high voltages using a differential probe and current flow with the relevant clamp (and much, much more) there is also a need for dedicated test equipment.

Zero potential checks & Insulation testing will become as regular as an oil service and these demands have been addressed with the introduction the Pico EV Kit. https://www.picoauto.com/products/elect ... id-vehicle

Zero potential testing is arguably one of the most important measurements you will ever make as your life depends upon it! In order to qualify the absence of voltage a robust test sequence in conjunction with the Pico 2-Ploe Tester will ensure beyond any doubt that your vehicle/machine is shut down.

Please visit the new Electric Vehicle Guided Tests within PicoScope 7 version 7.0.59.6966 here https://oem.picoauto.com/p7beta/download. Click on the Electric Vehicle icon & select Safety Tests > 0 V potential and open the “Guide and settings file”. Within this Guided Test you will find a link to a supporting video describing the application of the 2-Pole Tester

Post shutdown, insulation testing may be required; not only during diagnosis but to qualify repairs and installations. The Pico Insulation Meter has such measurements covered up to 1000 V along with the ability to save and export data to qualify the captured results.

The Pico Insulation Meter can also be used for those typical measurements you would expect from a hand-held multimeter, providing functionality beyond insulation testing. Once again using PS7 version 7.0.59.6966, click on the Electric Vehicle icon & select Safety Tests > Insulation resistance and open the “Guide and settings file”. Within this Guided Test you will find a link to a supporting video describing the application of the Pico Insulation Meter

Non-intrusive testing is fundamental to any diagnosis and 3 phase measurements are a typical example where the 3 x 2000 A current clamps included in the EV Kit will reveal motor/circuit integrity where access permits.

On the subject of non-intrusive measurements, the EV Kit includes a Coil-On-Plug probe which may raise an eyebrow for EV applications until you watch Ben Martins video here https://youtu.be/nQDU2LmxGE0 regarding the detection of AC at 50 Hz

At this stage, whilst we prepare for future challenges, we must not forget the opportunities presented by aging vehicles requiring diagnosis and hopefully repair. I say hopefully as often the diagnosis may conclude that the vehicle is beyond economical repair, however with that said, the diagnosis is still chargeable to the customer and reinforced using PicoScope

I could go on regarding the EV Kit but I think enough is enough other than to say the kit includes a PicoScope 4425A, 60-amp clamp, differential probe, test leads, appropriately rated probes and much more to ensure practically when diagnosing vehicles of the past, present and future

Whilst there is a wealth of information on the forum that is applicable to both Electric and ICE power sources, the following links most certainly sit well in this dedicated area for EV’s

RMS Calculation and profiling of AC Signals inc. 3 Phase AC current
viewtopic.php?p=98731#p98731

Cranking Comparisons between 48 V MHEV system and conventional 12 V system
viewtopic.php?p=98954#p98954

Electronically Commutated Motors
viewtopic.php?p=100521#p100521

Hybrid Relative compression testing
viewtopic.php?p=98813#p98813

EV and the importance of 12 V
https://www.picoauto.com/library/case-s ... ure-danger

EV Charging fault
https://www.picoauto.com/library/case-s ... ging-fault

Finally, please review our EV Guided Tests and videos below as they provide the initial support you need when applying PicoScope in EV applications

PicoScope 7 EV Guided Tests and supporting videos included within version 7.0.59.6966
https://oem.picoauto.com/p7beta/download

Finally, returning now to the 80’s, I can remember a tune played on Radio 1 that resonates as much now as it did then; The group was Timbuk 3 and the tune was aptly called “The future’s so bright I gotta wear shades” I believed it then and I most certainly believe it now


I hope the above helps, take care.......Steve

owense1
Newbie
Posts: 9
Joined: Sun Jul 10, 2016 12:06 am

Re: Welcome to EV

Post by owense1 »

Steve,

This is wildly cool and as ever about time. We are going in almost 20-25 years with Hybrid and ELectric vehicles. Finally, the aftermarket is gaining on the OEM dealers in terms of training and tools now. That is very cool and exciting.
Being one of the perks of being a Toyota Master is getting to deal with enormous amounts of Hybrid and Electric systems which most people hate but they don't realize emissions are only going to tighten their grip on the automotive market and finding those problems will take time and scope.
I hope you guys are in the process of doing more videos for electric vehicles. I understand some vehicle and systems will have proprietary constraints but the more knowledge the better the world. Fun was had by all and such.

Post Reply