Can you explain how an electrical transformer works and its significance in the power grid?

10/10/2024

The working principle and importance of power transformers in the power grid can be explained from several aspects:

Working Principle

The basic working principle of an electric transformer is based on the law of electromagnetic induction. It mainly consists of two windings, one called the primary winding (or first winding) and the other called the secondary winding (or second winding). When the primary winding is connected to an alternating current power supply, the current produces a changing magnetic flux that forms in the iron core, and this flux passes through both windings simultaneously.

According to the law of electromagnetic induction, when the flux changes, it will generate an induced electromotive force in the windings. If the secondary winding is connected to a load, then the current in the secondary winding will change according to the voltage in the primary winding and the ratio of the number of turns in the windings, thus realizing the transformation of voltage.

Specifically, when the voltage and current of the primary winding are determined, the voltage and current of the secondary winding can be calculated using the following formulas:

Voltage Ratio: The ratio of the primary voltage to the secondary voltage (turns ratio) of a transformer is equal to the ratio of the number of turns in the primary winding to the number of turns in the secondary winding, i.e.,

U2/U1=N2/N1

Current Ratio: The ratio of the primary current to the secondary current in a transformer is equal to the reciprocal of the ratio of the turns in the primary winding to the turns in the secondary winding, i.e.,

I2/I1=N1/N2

Importance in the power grid

  • Voltage Regulation: Power transformers can convert high voltage to low voltage or vice versa to meet the needs of different users. This is particularly important for long-distance transmission, as high voltage during transmission can reduce energy loss and improve efficiency.

  • Isolation and Protection: Transformers physically isolate circuits of different voltage levels to prevent current interference and circuit faults from affecting the entire system. They also have protective functions such as overload protection and short-circuit protection to ensure the safe operation of the power grid.

  • Improving Energy Efficiency: By adjusting the voltage, transformers can distribute electrical energy more efficiently, reducing energy loss during transmission and use.

  • Flexibility and Diversity: The diverse designs of transformers (such as step-up and step-down transformers) enable power systems to flexibly address different scenarios, including long-distance transmission, urban distribution, and industrial use.

  • Stable Power Supply: Transformers can adjust their output according to changes in power demand, ensuring the stability and reliability of the power grid.

To sum up, power transformers play a crucial role in the power system and are key equipment for ensuring efficient and safe transmission of electricity.



The Electricity Encyclopedia is dedicated to accelerating the dissemination and application of electricity knowledge and adding impetus to the development and innovation of the electricity industry.

What factors need to be considered when designing a transformer?
What factors need to be considered when designing a transformer?
Transformer design is a complex process that requires consideration of multiple factors to ensure safe and efficient operation. In addition, compliance with international and local regulations is essential to guarantee that transformers meet safety and performance standards. Below are key factors to consider in transformer design and the relevant regulations to follow:Transformer Design Factors: Voltage and Frequency: Determine the input and output voltage levels and the operating frequency. The
Vziman
09/02/2025
What failure modes are possible in a transformer? How to identify and fix these failures?
What failure modes are possible in a transformer? How to identify and fix these failures?
Transformers are critical components in power systems, and various failure modes can affect their operation. Timely identification and resolution of these failure modes are essential to prevent costly downtime and ensure system reliability. Below are some common transformer failure modes, along with methods to identify and address them: Insulation FailureIdentification: Insulation failure leads to decreased insulation resistance, which can be detected through insulation resistance testing (megge
09/02/2025
Fault Analysis and Treatment of Oil-Immersed Transformers
Fault Analysis and Treatment of Oil-Immersed Transformers
Oil Leakage at Welded JointsOil leakage at welded joints primarily stems from poor welding quality, such as incomplete or detached welds, and defects like pinholes and gas pores. Although oil-immersed transformers are initially coated with solder and paint during manufacturing, potentially masking these issues temporarily, the defects tend to surface during operation. Additionally, electromagnetic vibration can cause weld cracks, leading to oil leakage.To resolve such leaks, the first critical s
08/29/2025
Transformer Connection Sections
Transformer Connection Sections
Transformer Connection DesignationsThe transformer connection designation indicates the winding connection method and the phase relationship between the line voltages of the primary and secondary windings. It consists of two parts: letters and a number. The letters on the left denote the connection configurations of the high-voltage and low-voltage windings, while the number on the right is an integer from 0 to 11.This number represents the phase shift of the low-voltage winding's line voltage r
08/15/2025
Inquiry
Download
IEE-Business is dedicated to serving the personnel in the global power industry.
Join IEE-Business, not only can you discover power equipment and power knowledge, but also canhnd like - minded friends!