A lightweight, multilevel GaN maximum power point tracker for solar-powered race vehicles

The electrification of vehicles is spurring aggressive down-scaling of the size and weight of power processing components. Conventional approaches sacrifice efficiency and thermal handling to achieve these gains, but the flying-capacitor multilevel (FCML) topology, with its switching frequency multiplication effect, used in conjuction with fast GaN transistors, can reduce passive component size, and therefore system weight, without compromising efficiency. This work presents a maximum power point tracker system for use in a solar racing vehicle with a 3-level FCML GaN power stage, and is an order of magnitude lighter than competing conventional designs. The converter achieves a maximum efficiency of 98.6% at a nominal 2× boost ratio, can process up to 546 W of power, and is capable of a large boost ratio of over 16 x. In addition to achieving these metrics, factors affecting dynamic performance and reliability such as converter start-up and fault tolerance are addressed.