Renaults problems and engine test beds

In the winter testing thread we discussed the problems Renault and especially Red Bull are facing. From media reports and our own theories, Renault teams generally have problems with their batteries and power electronics. The Red Bull additionally seems to have a too tight package, so the electronics and/or batteries may get too hot.

The question arose if these issues couldn't have been found out "on the dyno" in the factory. First, "dyno" usually refers to the electric machine(s) used as a load for the engine and/or whole vehicle. The whole facility is called "test bed" or "test bench".

Disclaimer: The following is based on my experience from operating an engine test bed (don't want to post pictures here, just ask via PM if interested) and visiting dozens of such facilities at various vehicle manufacturers or research institutes. I will show examples of devices made by Austrian company AVL which is the #1 test bed manufacturer in the world and supplies, to my knowledge, all the F1 teams. Other than having good connections to AVL, I have no legal or commercial ties.
If anything is wrong or you know better, correct me!

An engine test bed looks like this - although of course they're never that clean
Image Unavailable, Please Login
An engine is mounted on a rig and connected to an electric machine ("dyno", the big blue box on the right) by a shaft. Lots of sensors connected, in the image you see in addition an exhaust gas analyzer next to the black hoses and on the wall in the back a fuel measurement system.

What you don't see: a cover on the engine, a car around the engine, or any hybrid components like in an F1 car. In fact, if electrified drivetrains are tested on an engine test bed, the electric motor may be mounted on the engine, too, and the power electronics may be present.
At that stage of testing, I have never seen any installation of the electronics like in the real car (ie, proximity to the exhaust etc), they're always mounted on a rack or so. And the power supply is never done with an actual battery, usually for safety reasons, lithium ion and so on. Either the electric motor is connected to the grid via an inverter, or the power electronics are supplied by a battery emulator. That's a control cabinet that emulates the electric behaviour of a battery, this is AVL's solution which F1 teams likely use.

The test of the power electronics is usually done seperately. They're fed by emulators like the one linked, and as a load, nowadays often electric machine emulators are used. They look similar to the battery emulator, big blue cabinets, and internally they behave like an electric machine. Here's a pic of a complete setup, the power electronics go into the rig on the right.
Image Unavailable, Please Login

The upside is that you don't need the mechanical installation of a real EM with all the safety measures necessary when operating a mechanically moving device.
It is possible to place the device under test, ie the power electronics, in a climate cabinet instead of the rig in the picture to stress it with any temperature desired. This is where you'd heat it up the the temperatures encountered in real life, and a fair bit beyond. If Renault now has problems with their power electronics, this is the step where they should have noticed.

The same goes for batteries - hook them up to a power electronics emulator (you guessed it, a big blue box) and off you go. However, battery testing is highly safety critical. Again, the likely F1 solution by AVL is a big container which has the testing devices inside. Here you can see how that looks. Notice the soild construction, the vents etc., no one wants a lithium fire spread around!
If the batteries are to blame for Renault's debacle, here they should have noticed.

This was component testing so far. When all comes together, the whole car is placed on a roller test bed, and this is a) the first time everything is in place and has to endure its neighbour components, and b) where I'm not sure if the F1 rules permit such a testing facility. If they do, it looks like the one in the video here (which happens to be the most advanced one in the world, belongs to a vehicle certification authority and is just a few kilometers from where I sit right now. I saw it in person, very impressive!).
[ame=http://www.youtube.com/watch?v=OfomHmC-yhI]TÜV Hessen Rollenprüfstand advanced im Technologie- und Umweltzentrum in Pfungstadt - YouTube[/ame]
You can safely bring the whole car to its limits on such a test bed. Manufacturers often have roller test beds in huge climate chambers to simulate extreme temperatures for the car while it is running (don't ask what such a facility costs!). If F1 has such test beds, at latest here Red Bull should have faced problems!

As I said, correct me if anything was dead wrong

 

I'm not sure if they have roller test beds in F1. Three possibilities:

1) F1 has no roller test beds and the Renault components all behaved fine under their individual tests. Then RB made a BIG mistake somewhere during the design phase. Overheating of that magnitude must be noticed during early (!) calculations

2) They have roller test beds and the RB behaved fine there with the Renault components. Then either the components were different, or RB made a BIG mistake during that test.

3) Renault components don't work as intended. This should have been noticed when testing the components, and not when the cars are on the track, and Renault made a BIG mistake.

You're welcome, mates

 

It's not only the batteries, everything has safety measures that go far far beyond what you'd experience in a normal car. You mention the fuel tank - in your car you carry 60+ liters of fuel around, which runs through rubber hoses to the engine.
At the test bed, the fuel is contained in absurdely expensive protected cabinets, everything is connected with stainless steel pipes, and don't ask what kind of certificates every part has to bring with it...

 

Sufficient enough for a conference paper, will have to do some work for my dissertation

Careful there! We're moving to a new location in April, out of our cramped containers into a real brick and mortar place, it will look considerably nicer then!

I haven't seen a shaker that allows operation of the car and can't imagine how such a facility would work. Below is a picture of the TÜV chassis dynamometer from the video above (this machinery is below ground, the car stands on the 4 rolling drums), you can't shake that with a high frequency
Image Unavailable, Please Login

 

Yup, but the car just stands on the shaker. It doesn't run!