Electric transformers are essential components in the intricate network of power transmission and play a critical role in modern society’s energy infrastructure. The two most crucial types of transformers are single-phase and three-phase variants. Each type has unique characteristics and applications that make them essential in their respective fields.
In this blog, we will discuss the differences between these two types of transformers, their structural intricacies, diverse applications, and consequential disparities.
Understanding the Basics: Single-Phase and Three-Phase Transformers
A transformer is a stationary electrical machine that changes the level of alternating voltage. It consists of a primary and a secondary winding, and works on the principle of mutual inductance. Transformers can be classified into two types based on the type of supply system they are used in: single-phase transformer and three-phase transformer.
What is a Single-Phase Transformer?
A single-phase transformer is a type of transformer that utilises a solitary pair of transformer coils or windings, including one primary winding and one secondary winding, to transform single-phase alternating voltage to the desired value. The primary winding is the winding of the single-phase transformer that connects to the single-phase AC supply, while the secondary winding is the winding to which the load connects.
Single-phase transformers are widely used in various applications, such as supplying electric power to domestic loads in rural areas where the demand and cost are lower, in home inverters, in welding machines, and in television sets and other electronic devices for regulating the voltage.
Advantages of a Single-Phase Transformer
Single-phase power systems are electrical systems that consist of a single wave alternating current (AC) power source. These systems have a simpler design compared to other types of power systems, making them more cost-effective to design and implement. Single-phase systems are capable of delivering AC power supply of up to 1000 watts efficiently, due to their enhanced efficiency. This makes them highly effective in various applications across a range of industries, including residential, commercial, and industrial settings. The versatility and efficiency of single-phase systems make them an ideal choice for powering a wide range of electrical devices and equipment.
What is a Three-Phase Transformer?
A three-phase transformer is a transformer composed of three pairs of transformer windings located in a three-section iron core. Each section contains a pair of primary and secondary windings and is used for stepping up or stepping down the three-phase alternating voltage. Alternatively, a three-phase transformer can also be created by using three identical single-phase transformers. This type of three-phase transformer is known as a bank of three transformers.
Three-phase transformers are commonly used in electric power systems for the transmission and distribution of electric power. As an individual three-phase transformer can supply three single-phase circuits, it is more cost-effective than a single-phase transformer. In urban areas, the majority of distribution transformers used are three-phase transformers. Additionally, numerous three-phase loads such as three-phase induction motors, synchronous motors, etc. are supplied by using three-phase transformers.
Advantages of a Three-Phase Transformer
One of the advantages of using three-phase transformers is that they require less copper for power supply. Additionally, operating on three-phase systems is relatively safe compared to other power systems. The three-phase system is highly efficient in terms of conductor performance and can handle a more extensive range of power loads. Three-phase systems are a reliable and efficient power solution for a broad range of applications.
Differences between Single-Phase and Three-Phase Transformers
Photo Credits: Carter Sullivan UK
The following table highlights the main contrasts between single-phase and three-phase transformers:
| Parameter | Single-Phase Transformer | Three-Phase Transformer |
|---|---|---|
|
Definition |
A transformer that is designed to adjust the voltage of single-phase alternating current, and consists of a single pair of windings - one primary winding and one secondary winding - is known as a single-phase transformer. |
A three-phase transformer is a type of transformer that has a three-section iron core with three pairs of transformer windings arranged in each section. The primary and secondary windings are a part of each pair of windings. Its primary function is to transform 3-phase alternating voltage to the desired value. |
|
Size
|
The size of a single-phase transformer is small. |
A three-phase transformer is relatively larger in size. |
|
Number of primary and secondary windings |
A single-phase transformer consists of a single primary winding and a single secondary winding. |
Three-phase transformer has three-primary windings and three secondary windings. |
|
Input and output terminals
|
A single-phase transformer has two input terminals and two output terminals: one for the phase (P) and one for the neutral (N). |
For a three-phase transformer, there are three input terminals for the line wires.
Additionally, one terminal is allocated for neutral, based on the connection type of the primary winding. The output side of the transformer also requires three line terminals and one neutral terminal, the provision of which is dependent on the type of secondary winding connection. |
|
Power handling capacity |
Single-phase transformers have a lower capacity to handle power as they utilise only one set of windings. |
A three-phase transformer has the capability to handle more power compared to a single-phase transformer. |
|
Winding configuration |
As there is only one primary winding and one secondary winding, no specific winding configuration exists in case of a single-phase transformer. |
Three-phase transformers have four winding configurations: Star-Start (Y-Y), Delta-Delta (Δ-Δ), Star-Delta (Y-Δ), and Delta-Star (Δ-Y). |
|
Efficiency |
Single-phase transformers have lower efficiency. |
Compared to a single-phase transformer, a three-phase transformer has higher efficiency. |
|
Applications |
Single-phase transformers are commonly used for small loads, such as supplying electricity to single domestic loads such as pumps and lighting.
They are also used in various electronic devices like TVs and mobile chargers for voltage regulation. In addition, they are used in home inverters for stepping up voltage. |
Three-phase transformers are used for supplying high power single-phase as well as three-phase loads as induction motors, etc.
They are also used in power systems for power transmission and distribution.
|
Driving Innovation in Power Transmission
In conclusion, the thorough exploration of single-phase and three-phase transformers highlights their indispensable roles in powering diverse sectors of society. UPT (Universal Power Transformers) understands the differences between these transformer types and their significance in ensuring reliable electricity supply. The adoption of UPT’s range of transformer services has allowed businesses to automate processes, reduce costs, enhance customer experience, and optimise resource utilisation, fostering innovation and growth.
By understanding and harnessing the strengths of each transformer type, UPT aims to optimise power distribution networks, driving innovation and sustainability in the energy sector.
