Versions Compared

Version Old Version 7 New Version 8
Changes made by

Jessica Lin

Jessica Lin

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

Current Proposal:

Capture.PNGImage Added


RequirementsTypeNotes
Leave at least 1mm spacing between each moduleTechnical

This is to allow some room for thermal expansion between the modules

Leave space for brake lights, hinge (and rear camera (question))WSC
Leave space for front (and back (question)) name plateWSC
Maximum 324 CellsWSC


Max array area: 5 m^2.


SunPower C60 Solar Cells: 0.01534 m^2. (info)

Total number of cells = Max area / Cell Area = 5 / 0.01534 = 325.9452411994785 ~ 324.

---

(info) Note that 0.01534 m^2 is an estimation provided by WSC.

Note that a more accurate calculation has been done here:

View file
nameSunpower cell dimensions.xlsx
height250

Each string should consist of around 32 cells

<SUPERSEDED>

Technical

We will have two stacks of 5 MPPTs in series, in parallel with each other, make 10 MPPTs in total. Thus 5 MPPTs in series should make up the battery voltage (151.2V - Battery Pack Design).

Each MPPT outputs 30.24V regardless of input (as long as it's between 10V - 30V), thus 5 MPPTs in series makes 151.2V.

The efficiency increases as the input voltage is increased, therefore to get the max efficiency, we want to spread out the voltage as evenly as possible to get the maximum input voltage between all the MPPT strings and get the most efficiency.

We can have a maximum of 324 cells on the car and there are 10 MPPT strings in total, there should be about 324/10 ~ 32 cells per string.


Each string should consist of around 27 cells

Technical

We will have two stacks of 6 MPPTs in series, in parallel with each other, making 12 MPPTs in total. The 6 MPPTs in series should make up the battery voltage (151.2V - Battery Pack Design).

Each MPPT can output between 23 - 37 V (info), thus setting the each MPPT to output around 25.2V.

This option replaced 5 MPPT in series due to improved flexibility for array layout and arrangement. Also dividing by 27 was easier since modules could come in 1x3s, 2x3s, and 3x3s. This made it easier to replace cells in the likely case of damages.

---

(info) From the Nomura Co MPPT Manual

...