Are you adding a new transformer, or perhaps replacing an existing one? Is the transformer’s phase shift different compared to another transformer in the same yard?
You need to get two things right when it’s time to parallel two transformers at a substation.
Power System Fundamentals
Power system fundamentals covers short-circuit studies, load flow studies, arc flash studies etc. Articles here cover some of the basics too which are important if you want to understand some of these studies. The basics include per unit systems, symmetrical components, current ratings etc.
One problem that is pervasive in the power grid and not well understood is called the Transient Recovery Voltage (TRV). When a short-circuit due to a fault in high voltage or medium voltage system is switched-out by a circuit breaker, the voltage across the breaker poles rapidly increases; as high as twice the operating voltage. …