Miniaturized High-Frequency Matrix Transformers for Electric Vehicle Onboard Chargers

About the thesis

Electric cars... unfortunately, they need to be charged. For that, we use a charger that works much like a phone charger, only about a thousand times more powerful. What many people do not know is that this charger is built into the car itself. It is like having your phone charger inside your phone: if that were the case, you would of course want it to be as small and light as possible. Yet the onboard chargers in today's electric cars are still about the size of a crate of beer. So they need to be downsized to make room for batteries, passengers, or luggage. Such chargers are a complex puzzle of thousands of components, but one piece stands out: the transformer, because it often takes up about a third of the space. We use the transformer to take electrical energy from the grid, convert it into tiny pulses of magnetic energy, and convert them back into the voltage and current the battery requires. It processes a lot of power, so if we simply make it smaller, it will overheat and melt. This work, therefore, investigates how to make these transformers tiny without melting them. Two new ideas are presented that fundamentally rethink how such transformers are built.