All power transformer manufacturers maintain computer programs that compute the internal transient voltage distribution when the transformer is subjected to transient voltages. This information is used to design the insulation structure for the transformer. Utility engineers also need to represent the power transformer in some detail for their system studies since significantly higher failure rates on large EHV units suggest the transient voltage that the system places on the terminals of the transformer are in some measure a function of the impedance characteristic of the transformer. Currently, no method exists to conveniently link the detailed lumped parameter model of the transformer designer to that required by the utility engineer. This paper presents a reduction technique which uses the detailed lumped parameter transformer model as a starting point and allows its reductions to any size specified by the user. The method is straightforward mathematically and while retaining the physical configuration of the transformer does not require any proprietary information from the transformer suppliers. The paper presents the necessary mathematics and illustrates the method by example using a 500 MVA autotransformer constructed by ABB for AEP.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.