I'm aware that 30° shift is needed in order to obtain a 12-pulse rectification, however, I'm a bit confused about the configuration of these transformer. In most HVDC systems that appear in Alstom - HVDC for Beginners and Beyond, for example, shows a WYE winding as primary:
However, I stumbled upon this similar ResearchGate question but it was answered as the Y/Y/Δ configuration is used and that's why I got confused.
I'm doing a simulation on PLECS in stationary state of this series connected 12-pulse rectifier so as long as I can represent leakage inductances and 30° shift it's okay as I won't do neither a transient analysis nor a fault scenario. However, I want to clarify this to at least justify why I used one configuration or the other.