Abstract
Installing a new transformer in a transmission substation can greatly increase the amount of load that can be handled for an area. An ideal fix for an engineer would be to parallel two transformers that are completely identical. However, the economics does play a large role in the installation of a newer, larger transformer. Due to transformer manufacturing, utility standardization, transmission planning, and economics the alternative for engineers is to install a larger bank in parallel with an existing smaller transformer so that the load can be divided amongst the two banks. In doing this the engineer is looking to get an even load on the paralleled transformers so that they can be utilized at their maximum capacity.
This project will look at different aspects of the installation of new transformers in parallel with an existing transformer. The project will look at the operational considerations that need to be taken into account when installing the transformers in parallel. The different mismatch possibilities and their effects will be researched along with different paralleling methods of transformers. How the settings of a transformer with a Load Tap Changer (LTC) effect the system and possible methods used to set the LTC's along with the de-energized load tap changer (DETC) as to minimize circulating current will also be researched. All these pieces will initially be calculated by hand and their results will be placed in a GE PSLF, positive sequence load flow, computer program to simulate the load flow considerations that operation engineers need to use to maintain the integrity of the power system.