Sunstang attended the Formula Sun Grand Prix at the Circuit of the Americas in Austin, Texas with its Challenger Class solar vehicle: Sunstang 2017. At the competition, our team was awarded the Perseverance Award by the Innovators Educational Foundation.
CHASSIS, SUSPENSION & BRAKES
The chassis of Sunstang 2017 was a high strength aluminum tubular space frame that could withstand over 5g of force. This provided the required high strength to weight ratio. The suspension was made from high strength steel, utilizing a dual unequal length a-arm design, as well as in-board shocks for easy adjustment and lightweight cast magnesium wheels. The car’s brakes were a hydraulic disk set up using custom designed rotors and driver pedals machined from high strength aluminum.
The aerobody design is unique to solar racing due to the solar array. The body was made from layers of Kevlar and fiberglass, with carbon fiber sandwich panel reinforcements. The unique shape and materials of the body allowed for a large flat surface for the solar array, optimized aerodynamics, and a low vehicle mass.
The motion of the solar car comes from a brushless DC in-wheel electric motor. The CSIRO motor was controlled using a WaveSculptor motor controller, which was fine tuned and adjusted in order to allow for power when necessary while also maximizing efficiency.
Battery & Solar Tech
The blood of a solar vehicle is electricity, which would make the batteries the heart. We used lithium polymer cells in our battery pack, giving us a rating of 120V nominal at 30Ah. The Battery Protection System’s primary objective is electrical safety: it simultaneously monitors and maintains safe levels of current, voltage, and temperature of the battery pack. Telemetry takes data from all systems of the car for monitoring and diagnostics, sending this info to the driver display and to an off-board computer for real-time analysis. The solar array was comprised of mono-crystalline cells, chosen because of their high efficiency, allowing us to use a small surface area to achieve a high power output.