Delta-Wye Conversion

Delta-Wye transformation is an additional method for the transformation of such resistor configurations that can not be controlled by sequence and parallel equations. This is often referred to as the Pi-T transformation. Such resistor networks cannot be generalized by using the regular series and parallel combinations. Describe the equations that relate the resistances in a Wye (Y) and Delta (Δ) resistor network. Δ−Y transformations are another tool in your bag of tricks for simplifying circuits prior to detailed analysis

Delta Circuit

The delta circuit is a three-wire circuit and the wye circuit may be either a three-wire circuit or a four-wire circuit. They vary in the way they are intertwined in a different way.

A delta connection is a three-wire circuit used in a three-phase electrical system in which three elements resemble a triangular arrangement of three-phase electrical windings. The delta connection, also known as the Mesh connection, is named for its similarity to the Greek symbol "Δ" and is created by joining one end of the winding to the starting end of the other and the connection is continued to form a closed loop.

Wye Circuit

Wye connection is a three-phase four-wire circuit used in a three-phase electrical network and is created by connecting the signal or terminal ends of all three windings together. This common point is called a neutral point defined by "N." Wye (Y) connection, also known as "Y" connection, is a three-phase circuit in which all three loads are connected to a single neutral point. Unlike delta connection, the wye-connected networks have a fourth neutral conductor, sometimes grounded but often left floating (ungrounded wye system).

Importance of Delta - Wye connection

Electricity is currently a need to lighthouses and residences, to run air conditioners and to drive trains. In reality, electricity drives almost all, such as computers, radios, televisions, medical equipment and an ever-increasing range of appliances, which continue to enhance the quality of life of millions of people around the world. At the root of all this electrical strength, a three-phase electrical power system is the heart of all this electrical power network. The three-phase system is the foundation of the electrical power delivery and the electricity is produced in three distinct phases, each with the same frequency and voltage but with a voltage change of 120 degrees in any two phases. The three phase system is the most popular distribution network used in use all over the world. There are a variety of special issues for three-phase circuits which do not occur for single-phase circuits. Three-phase circuits may be designed either in a delta configuration or in a wye configuration. The design of the delta is named for its similarity to the Greek symbol "Δ." They are popular with industrial power systems. The wye (Y) configuration, as the name suggests, is also referred to as the "Y" circuit and sometimes the "Star" circuit. The delta circuit is a three-wire circuit and the wire circuit may be either a three-wire circuit or a four-wire circuit. They vary in the way they are interconnected in a different way.

2 of the terminals are connected at one node. This node is a distributed node in case of Π network

Delta to wye conversion formula

R1 = RA * RB

RA +RB+RC

R2 = RA * RC

RA +RB+RC

R3 = RB * RC

RA +RB+RC

Wye to Delta conversion formula

Delta vs wye connection

Configuration of Delta Vs Wye

Three-phase circuits may be designed either in a delta configuration or in a wye configuration. The delta connection is also known as a mesh connection and is named for its resemblance to the Greek "Δ" symbol. Delta configuration, all single-phase loads are concentrated in one phase, while all single-phase loads are distributed in each of the three-phase configurations. The delta configuration uses only three-phase conductors, while the wye-connected systems have a fourth neutral conductor, which is often grounded but sometimes left floating. Unlike in delta connection, all the three loads are connected at a single neutral point in wye connection.

Connection of Delta Vs. Wye

Wye connection is a three-phase four-wire circuit used in a three-phase electrical network and is created by connecting the signal or terminal ends of all three windings together. This common point is called a neutral point, represented by "N." The neutral cable is attached to the middle where the three phases cross. The delta connection, on the other hand, is a three-phase circuit created by connecting one end of the winding to the starting end of the other, and the connections proceed to form a closed loop that forms a triangle.

Cost

The configuration of the delta is cheaper if you factor in moving power due to the fact that it requires only three conductors but not four, lowering the cost of equipment and construction. Even though voltage drops and losses are equivalent, at least if the power flow is balanced. Wye-connected lines, however, lead to a less expensive distribution system because transformers, reclosers and lightning arresters for wye-connected systems cost less than their counterparts in delta-connected systems. A single-phase service transformer needs only one high-voltage bushing for wire systems, while two is required for delta systems.

Application

Delta configuration is mainly used in distribution networks while wye configuration is used in both transmission and distribution networks. Delta systems are often found in applications that need a high starting torque. Whereas wye connections are ideally preferred for applications that require less starting current. The delta connection is used for shorter distances while the wye connection is used by power transfer networks with longer distances. Delta was mainly used in small industrial installations with a relatively large (240 VAC) motor load but only a small need for convenience outlets and lighting.