Automated Power Converter Topology Derivation Methodology Based on Exhaustive Graph Search

Abstract

Due to increasing electrification, there is a need for new power converter topologies. Traditionally, deriving these topologies require skill and experience. Recently, graph theory has been employed in an effort to automate the formation process of nonisolated converters with dc ports. This article proposes an extension of this methodology, introducing ac ports and isolated topologies. This is accomplished by taking into account the directional properties of the power electronic components. As a result, a distinction can be made between unidirectional/bidirectional and dc/ac ports. Besides, other asymmetrical characteristics, such as the need for bidirectional switches, can be verified. Furthermore, the methodology provides a solution for the inclusion of components with more than two terminals. This allows for the introduction of isolation transformers. After the derivation of candidate topologies, the voltage relations and current flows are automatically checked, verifying the operational boundary conditions. The article demonstrates the proposed methodology in a PV-battery system use-case. This showcases the resulting original circuits incorporating a dc input port, dc bidirectional port, and ac output port.