incorporation of motor model in ADVISOR

[Swagata Borthakur]

Hello Michael,

I want to incorporate a new motor model in ADVISOR. I went through the discussion forum and similar question had been raised before. You suggested to start with an existing data file (for example, MC_AC75.m in data/motor) and resave it as a new name and update the data in the file to match the system. I have the model data with me, but I am confronted with the following doubts:

1. in the .m file, we have mc_map_trq (torque range of the motor) vector and mc_max_trq vector (maximum torque curve of the motor indexed by mc_map_spd). The data I have is of mc_max_trq. What should I incorporate on mc_map_trq?

2. Both of the above vectors are formulated with a multiplying factor of 4.448/3.281. example

mc_max_trq=[200 200 200 175.2 131.4 105.1 87.6 75.1 65.7 58.4 52.5]*4.448/3.281; % (N*m) ( from AC_75.m)

Can you please elaborate on the factor?

3. I don't have the data for the efficiency map. But I have the maximum efficiency of the motor (96%). Will it be safe to use the efficiency map of the already existing motor model?

Anticipating for a quick feedback

Thanks in advance

[Michael P O'Keefe]

Hello Swagata,

Yes, it can be tricky when you only have partial data. You can add your known mc_max_trq for the mc_map_spd you have. 

1. For mc_map_trq, you basically need to have efficiency data for every combination of mc_map_trq and mc_map_spd. If you don't know what that information is, perhaps you can use an existing map's data and scale the efficiency data so that max efficiency corresponds to what you have.

2. I can't exactly explain why those exact factors are used but I know it is for the conversion from ft-lbf to N-m. Probably, the data from the manufacturer was in ft-lbf. As an aside, one excellent resource for unit conversions is Frink: http://futureboy.us/fsp/frink.fsp

3. Well, there is nothing else you can really do. You may look at the motor file labeled "ideal" as that gives you a constant efficiency across the board which can be used to "bracket" your results to see how much efficiency affects your answer. We typically had to scale some data as best we could. It depends what you want ADVISOR to do for you as well. If you are using it to explore the affect of different strategies for energy management, you just need something representative.

Hope that helps,

Michael

[Swagata Borthakur]

Thank you Michael. Indeed the conversion factor from lbf-ft to N-m is 1.3558 (4.448/3.281). Too bad it didnt strike me ;)

[Swagata Borthakur]

Thank you Michael for your advise.

I am able to procure my motor model ( although I have relaxed the efficiency curve). I took the help of MC_AC75_IDEAL and could develop my motor curve. 

I have the following issues:

1. When I select MC_AC75_IDEAL, the curve shows up, but in the matlab command line I get the following message

Undefined function or variable "levels".

Error in ==> clabel>plus_labels at 565

    crange = max(abs(levels));

Error in ==> clabel at 83

            h = plus_labels(cax, threeD, cs);

Error in ==> gui_inpchk at 562

        clabel(c)

 

??? Error while evaluating uicontrol Callback

Although it didnt affect the final results, yet I am curious to know why this happened. The same case with my motor model (since I followed the efficiency curve of MC_AC75_IDEAL)

2. For optimization, I would like to use my motor model along with a few changes in generator, engine and the overall mass. I was thinking if I could save my vehicle before running the optimization ( which would be a series hybrid), and then  instead of initializing the SERIES_DEFAULTS_in in the main optimization file, I could initialize my vehicle and run the optimizer.

How can I save the vehicle? Is the save button in the vehicle input page enough to save my vehicle?

Thanks in advance

[Michael P O'Keefe]

Sorry for the lateness of my reply.

1. I'm not quite sure what happened with the levels issue. I have captured it in the issue tracker here and will look into it when I can:

https://sourceforge.net/p/adv-vehicle-sim/tickets/33/

I'm suspecting that the levels variable is not getting created? Perhaps because the AC_75_IDEAL has a constant (flat) efficiency curve? I'm not certain...

2. Sure, you can save the vehicle with the save button. You can look at the saved_vehicles folder to see what's going on. adv_no_gui also offers a save vehicle function if you are using the command line. Try saving the vehicle and the load it again to convince yourself it is working correctly.

Thanks,

Michael