This is related to the Operating Solar plant. Our contractor has replaced an Inverter skid unit transformer of ungrounded Yd1 configuration with the similar KVA rating of ungrounded Dy11 Transformer. It worked for few months and failed recently. We came to know about this vector configuration change recently and working on RCA. What are the consequences of this vector configuration change and affects on the Inverters as well as substation protection? All the remaining electrical parameters of both the transformers are same. Please see the attached nameplate details of both units. The RCA might be something else also, we are trying to analyze whether we can do this replacement again with Dy11 as we don't have any Yd1 Transformers available immediately?
Original configuration: Yd1 Ungrounded
Replacement configuration: Dy11 Ungrounded
Original configuration: Yd1 Ungrounded
Replacement configuration: Dy11 Ungrounded
