Re: [sumo-user] FW: Electric wehicle def.

[The div <div@xxxxxxxx>]

My 2p

The original model was based on measurements from a Bus transit system quite some time ago - one might think that battery/drive train/recuperation efficiencies would have improved considerably since then. 

I was interested in modelling my own passenger ev (kia soul) and trying to get close to my observed behaviour. 

I started with a sensitivity analysis against the various parameters in the model and determined that most impact was from the efficiency values, vehicle mass and the radial friction. (frontal area didn't have much impact until speeds > 70km/h)

In artificial networks (straight roads, x junction etc) I could not get anywhere near my observed efficiency - the model efficiency values were too high, but reducing these gave unpredictable results. I believe achieved speeds were simply too high. 

I then tried realistic networks - extracting roads from openstreetmap. 

I found that I needed much higher efficiency values to replicate observed behaviour. 

Obviously this was reflecting a single vehicle albeit across many short (5-15km) routes and several longer routes (400-700km).

My conclusion was that real world road layout, speed limits, roundabouts, junction topologies etc are needed to properly invoke a realistic relationship between speed, acceleration and deceleration (recuperation) 

The values I finally submitted got me within better than 10% of observed, close to WLTP and this was still valid in journey prediction. 

Obviously ymmv! 
:) 






-------- Original Message --------
On 2 Nov 2023, 14:32, Mirko Barthauer via sumo-user < sumo-user@xxxxxxxxxxx> wrote:

Dear Petró,

 

although the model described in the cited publication has been integrated into SUMO, it was a third-party contribution. I get your message that the default values of some model constants like the efficiency factors might be unrealistic. Even if I leave out losses at tire level (as road friction isn't considered in other parts of the simulation either), I get still way lower efficiency than the default values. Could you please give as the reference you took the efficiency table from? Then we can discuss internally how to deal with that.

 

If you want to discuss the topic with the original author, you can find him e.g. on LinkedIn. His thesis includes an extended description of the model (German only).

 

Best regards

Mirko

 

 

 

 

-----Original-Nachricht-----

Betreff: [sumo-user] FW: Electric wehicle def.

Datum: 2023-11-02T14:42:34+0100

Von: "Petró János via sumo-user" <sumo-user@xxxxxxxxxxx>

An: "sumo-user@xxxxxxxxxxx" <sumo-user@xxxxxxxxxxx>

 

 

 

Dear Developers

 

We would like to use SUMO for make a simulation of electric city bus.

Please help for us the following questions.

 

About the SUMO Proceeding description the Vehicle Energy Model working on:

 

 

In case ηprop is the efficiency of the total driving system between the battery and the roadway.

Some other study has efficinency of the driveline elements and power converter:

 

1. So is it correct to calculate the ηprop=ηdrive equal „Forward” mode? Because of ηdrive ≈ ηb * ηm *  ηco *  ηtire ≈ 0.72, so usually ηprop need to be 0.70÷0.80 in „Forward” mode?
2. Pconst. is the average power of constant consumer like heating, cooling air ventilationing, air compressor, etc. which get energy from the battery via power converter (ηpc =0.95). The equation (3)->(2)->(5) the battery energy decreasing by the constant consumer energy (with some others): Econst / ηprop. It looks like the constant consumer energy goes trought the total driving system. Please clarify for us if we think wrong, because of this calculation cause higher consumption of constant consumer.
3. Please clarify for us what Recuperation efficiency – ηrecup – means exactly. Is it the efficiency the total driving and power converter system from the tires to the battery? So is it correct to calculate the ηrecup=ηdrive equal „Backward” mode? Because of ηdrive ≈ ηb * ηm *  ηco * ηco *  ηtire ≈ 0.56, so usually ηrecup need to be 0.50÷0.60 in „Forward” mode?
4. Or should be use?

 

Thank You for Your short answer.

 

Best regards,

Petró János