Multi-tap bus communication for modular power converters with distributed isolation

Inhalt:
A centralized communication system is state-of-the-art in modular power converters. Modular communication topologies, e.g. a ring, have an increased latency. This paper analyzes the DC-pole fault scenario in terms of delayed communication. We propose a multi-tap bus that virtually eliminates the latency for switching commands. The bus features a distributed isolation system based on digital isolator ICs. Each isolator must be rated only for the potential difference of two adjacent converter modules. The theoretical results are supported by a communication system demonstrator, to verify the physical layer and shared medium access functionality.