One of the well-established key requirements in solar inverters is their high efficiency. But also, their costs, size and weight are subject to continuous improvements. One approach to better fulfil all these demanding requirements simultaneously is the use of multilevel topologies.
The main advantages of switching between multiple voltage levels are lower voltage stress for the semiconductors and lower ripple stress for the power chokes.
This means that lower-voltage semiconductors can be used, which are typically cheaper.
Lower ripple stress for the chokes makes smaller and thereby lighter and cheaper choke designs possible.
The flying capacitor topology is a multilevel topology, that is an interesting choice especially for (but not limited to) the booster stage of a solar inverter. As its name implies, it needs a capacitor as a key element. This article describes and compares possible TDK solutions therefor.