Three phase transformers are a vital component of industrial and commercial power systems. They are able to produce more energy than single-phase transformers, while also providing greater stability in voltage levels.
There are several different ways to connect the windings of a three phase transformer, including delta and star connections. This article will discuss some of the most common methods for connecting these three phase transformers.
Star-Delta Connection
The primary ways to connect a three phase electric supply is in Star and Delta connections. A Star connection is a 4-wire system with the line voltage root three times the phase voltage and is considered a balanced circuit.
In a Star connection, the starting and finishing ends (similar) of each of the three phase wires are connected to one common point or Star point and a neutral wire is taken from that point. This configuration is also known as a Y or Wye connection.
In the Delta connection, the opposite ends of each of the three phase wires are directly connected to each other. There is no Neutral Wire in a Delta connection. This configuration is most commonly used for industrial motor applications. It is important to note that a motor connected in Delta will draw more phase current than the same motor connected in Star. This is due to the fact that a Delta connected motor does not have a neutral conductor which is required to carry the out-of-balance current.
Delta-Delta Connection
In a Delta connection, the head and end of each phase winding are connected together. This can be done with three single-phase transformers or with one pre-assembled and balanced three phase transformer.
This type of connection is used on larger distribution transformers to reduce the impact of SLG faults on the primary system. This is also the preferred connection for high power factor loads.
This configuration consists of two pairs of single-phase transformers that have their secondary windings combined onto one core, making it more compact and affordable than other options. However, it can create problems with unbalanced loading because high currents can circulate in the delta windings. This type of connection can be difficult to maintain due to the requirement for a stable neutral point. If the delta-delta bank isn’t properly grounded, it can result in a large voltage imbalance across the three phases. This is why it’s important to use surplusrecord.com to find a reputable seller that can provide an accurate, reliable three-phase transformer.
Wye-Delta Connection
There are two main ways that a three phase transformers can be connected: Delta and Wye. Both are common in power systems. Both can be used for line-to-line or line-to-neutral voltages.
The delta and wye configurations are named for the shape they resemble once they're connected together. A delta has three windings that connect end-to-end, with one of the corners grounded. A wye has four wires, with three being phases and the fourth being neutral. The wye-delta transformer is commonly used in medium and high voltage applications. This configuration is often found in substations, generating stations and transmission lines. It's also common in distribution networks. It's possible to convert a delta network into a functionally equivalent wye network and vice versa, but the conversion process can produce a current spike that requires special circuits (like EMI filters) to mitigate.
