A More Extensive Look at Astra’s Design
Astra is KU Solar Car’s very first solar car and as a new team, cost, and ease of manufacturing were key factors in our design decisions. Much of the design had to be pioneered from scratch due to not having a previous car design to work from. Below we further explain and break down the important parts of the car.
The body of the car follows a monohull design which is often depicted with a bullet-like shape. The monohull design allows us to make a very aerodynamic yet cost-efficient car that does not require a complex manufacturing process. The body is made of fiberglass and foam core which provides a strong shell to protect the driver and components within the car.
The battery pack is made with 416 LG MJ1 Li-Ion cells which provide a 5000 Whr of capacity to power the car. The battery pack is monitored using the Orion 2 Battery Protection System.
The solar array is made of 235 Sunpower Maxeon Gen III solar cells which cover 3.6 m^2. Power from the solar array is controlled by three Drivetek V4 maximum power point trackers which have an estimated output of 1000W.
Chassis and Suspension
The chassis is a Chromoly steel tube frame that is welded together. The front suspension utilizes a double A-arm design and a swingarm is implemented in the rear. The suspension configuration was chosen because of ease manufacturing and to have the wheelbase fit the narrow monohull design.
Astra uses a rear-mounted 72 V, 4000 W in-hub car motor. Most solar cars use in-hub motors because they don’t require a transmission gear system and provide direct drive to the car which saves space and weight. The motor is equipped with regenerative braking which converts braking energy to charge the battery pack.
Michael Srimongkolkul // KU Solar Car Engineering Director