Week 10 - UCAP Update, Power Curves, Flow Chart. Mechanism Cad/Materials, etc

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Actual Flow chart for Controls and wayside teams to program (event-driven):



This week there were a lot of changes in motor specs and power requirements but it looks like we will be running with 2 Hub motors now instead of four. This changes our numbers slightly but we have modified them.
We are thinking of getting two of each of these for a total of 4 UCAPs:https://www.digikey.com/products/en?keywords=BMOD0083%20P048%20B01
and
https://www.digikey.com/products/en?keywords=BMOD0165%20P048%20C01.

The difference in Capacitance will allow us to fully charge the onboard to about 48V. 

ON-BOARD UCAPS DISCHARGE CURVE WITH 1000W LOAD: (for two motors, 500W each). This will be made up of two 48V 83F each in parallel.
This means we are fairly certain we can run the bogie without having to recharge again for at least a minute and a half without to much current draw from the motors. 

CHARGING CURVES FOR RAPID CHARGING FROM SOLAR BANK TO ON_BOARD BANK: High current discharge from 96V source charges on board UCAPs to a maximum of around 47.5V (not shown here, will update next week.) Using 165F UCAPs for solar. 

USING SOLAR BANK TO ACCELERATE OUT OF STATION 
A DC DC Converter will be used to convert the voltage from 96-42V to a constant voltage between 48-24 and a current output of 12-25A. The solar bank will have two UCAPs in series to increase voltage. This will ensure the motor does not receive a large voltage and the bogie can accelerate at any charge percentage (not only below or @ 48V) . Example of DC DC Converter https://www.mouser.com/ProductDetail/Cincon/CFB600W-110S24?qs=sGAEpiMZZMsc0tfZmXiUnQ%252bwKZhbvwnuoAeuSPCrWldoakmu%252bwBZ0A%3d%3d
This may change since we don't want to sacrifice charging time just to be able to use wayside rails to accelerate. We may have to add another small UCAP bank.

 

EXAMPLE CURVE FROM LT SPICE CALCULATION FOR BACK EMF CURRENT AND MOTOR VOLTAGE
For this calculation to be accurate we need motor constants, motor winding resistance and J inertia value through the axis of the motor for the whole bogie drive/slave system and added person.

Here is the LT Spice code: (to open copy this and save a text file as a .cir file and open with LT Spice)
 DC_MOTOR_MODEL.CIR
*
V_AMP    1    0    AC    1     PWL(0MS 0V   1MS 36V  1000MS 36V  1010MS 0V   2000MS 0V)
*
* MOTOR VOLTAGE
RA    1    2    0.5
LA    2    3    0.0015
H_EMF    3 4    VSENSE2    0.05
VSENSE1    4    0    DC 0V
*
* MOTOR TORQUE BASED ON INERTIA AND FRICTION
H_TORQ    6 0    VSENSE1    0.05
LJ    6    7    0.00025
RB    7    8    0.0001
VSENSE2    8    0    DC    0V
*
* MOTOR POSITION
FPOS    0    11    VSENSE2    1
CPOS    11    0    1
RPOS    11    0    1MEG
*
* ANALYSIS
.TRAN    10MS    2000MS
*
* VIEW RESULTS
.PRINT TRAN V(1) I(VSENSE1)
.PROBE
.END

Comments

  1. Eric HagstromOctober 30, 2018 at 12:13 PM

    Full Scale Wayside Team,

    Excellent work. I have also reviewed your presentation 2 and am impressed by the CAD / analysis completed. Please keep it up!

    As I have told the Steering & E-Brake Team, and the Controls Team, you three teams are ahead of the curve. Please ensure that your other full scale teams have the support they need in order to complete their work on time, because in the end, all of your full scale teams need to successfully integrate together.

    I am excited to see some ultracaps demoed!

    Thank you!

    ReplyDelete

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