Description of the electrical team
Our team is finishing off the design of the battery pack. This includes CADing it and integrating it to the main electrical system. This is important because the battery will serve as the cars energy storage system. Without it the car won't work. We are implementing 416 Li-ion Panasonic 18650 NCRBE's manufactured usingwire bonding to ensureproper connections.
The motor team is doing power flow analysis based on the info that we currently have to create a race plan. One of the troubles that we are having is that the motors that we are planning to use are really expensive, but yet are the only motors that can work for this type of project. Other motors are a lot less expensive but are too heavy/inefficient. The power flow analysis help help us see if switching to another motor would cause that big of a change and switching motors is something we may have to consider since money may be an issue.
Currently we are working on communicating our telemetry with the Battery Management System. Up to this point, we have achieved communication via CAN bus, zigbee networks(one form of wireless communication protocol), and retrieving voltage/current data. Once we finish with the BMS system, we'll move onto transmitting our data via wifi, setting up a database and creating a user interface (possibly web app) where any of our team can log in and view the data of the car. We will also be implementing a camera to the car which will display to a small screen. We plan to make an app on that screen where the driver can also view the data of the car. Our progress has been mostly limited by funding so the progress we have made is by parts paid for out of pocket by myself. We are also waiting on the MPPT to arrive so we can begin tests with that. The reason why the telemetry system is vital to the vehicle is because it allows us to track important data from different points of the car that we otherwise wouldn't know. Important data, for example, could be the voltage of each section of the solar array, the temperatures, temperatures of the battery sections, balance of the batteries, power provided, any faults (failures throughout the car), if a component has stopped working, speed, gps location, tire pressure (if a tire has popped), etc. Many of these issues that could arise in an endurance race we would not be able to see with the naked eye, especially being that we have to be somewhere away from the solar vehicle. The system could not only allow us to locate and resolve issues immediately, but also allow us to optimize our vehicle and strategize to win.
Currently we are working on a test system to simulate power and collect data on how the solar array, motor and battery will interact with each other. This will allow us to understand how the power will flow from the array in to the motor and battery. This is important because we are not entirely sure how power will flow from the battery if the motor draws more power than the array is providing. The car will consist of 256 Sunpower Maxeon C60 bin kp solarcells (2 sub arrays with 128 cells each and sub array will be made of 7 modules).