What is Transformer? | Definition, Working principle, Types, Applications, History, safety measures

INTRODUCTION

Electrical transformers are the devices that change the voltage level of electricity in power transmission as well as in distribution systems. They play a crucial role to ensure that the electricity generated at the power station is delivered to homes, businesses, and industrial equipment at the appropriate voltage levels.

Transformers work by using electromagnetic induction to transfer energy from one electrical circuit to another. They have two or more coils of wire, called the primary and secondary winding. Electric current flowing through the primary winding creates a magnetic field, which induces a current in the secondary winding. By adjusting the ratio of turns on the primary and secondary winding, the transformer can step up or step down the voltage level as needed.

The use of transformers allows for the efficient and reliable transmission and distribution of electricity to homes, businesses, and industries. They are essential components of the electrical power industry and their importance cannot be overstated.

HISTORY OF TRANSFORMER

The history of the electrical transformer dates back to the early days of the electrical industry in the late 19th century. The first known electrical transformer was invented by George Westinghouse in 1885. At the time, electricity was primarily generated by direct current (DC) generators and was limited in the distance it could be transmitted before losing power. Westinghouse recognized the need for a device that could step down the high voltage used to transmit electricity over long distances to the lower voltage used in homes and businesses.

He developed the first practical transformer, which used two coils of wire wrapped around a core made of iron. The primary coil was connected to the source of electrical power, while the secondary coil was connected to the load. By adjusting the number of turns in the primary and secondary coils, the transformer could change the voltage of the electrical power.

This invention made it possible to transmit electricity more efficiently and safely over long distances and was a major milestone in the history of electricity. It was the key technology that made the widespread distribution of electricity possible and led to the development of the modern power grid.

DEFINITION OF TRANSFORMER 

A transformer is a static electrical device that transfers energy from one circuit to another circuit by using electromagnetic induction. It steps up or steps down the voltage of the electrical supply by avoiding changes in the frequency.

WORKING PRINCIPLE OF TRANSFORMER 

Transformers work on the principle of electromagnetic induction, which was discovered by Michael Faraday in the early 19th century. Electromagnetic induction states that a changing magnetic field within a coil of wire will induce a current to flow in that coil.

A transformer has two coils of wire, called primary and secondary windings, that are wrapped around a core made of a magnetic material such as iron. The primary winding is connected to the source of electrical power, and the secondary winding is connected to the load. The primary and secondary windings are not connected directly to each other but are instead connected through the magnetic field of the core.

When electrical power is applied to the primary winding, it creates a changing magnetic field within the core, which induces a current to flow in the secondary winding. The ratio of the number of turns in the primary winding to the number of turns in the secondary winding is called the transformer's "turns ratio."

The voltage in the secondary winding is determined by the turn ratio and can be either higher or lower than the voltage in the primary winding, depending on the transformer's design. If the secondary winding has fewer turns than the primary winding, the transformer is called a "step-down" transformer, and it reduces the voltage. If the secondary winding has more turns than the primary winding, the transformer is called a "step-up" transformer, and it increases the voltage.

The transformer's ability to change voltage levels is because the electromagnetic field through the primary winding induces an electromotive force (EMF) into the secondary winding. The voltage in the secondary winding is directly proportional to the number of turns in the secondary winding and inversely proportional to the number of turns in the primary winding.

The transformer also isolates the primary and secondary circuits electrically, which means that the primary circuit and the secondary circuit are not connected to each other and there is no electrical contact between the two circuits. This allows the transformer to transfer energy from one circuit to another while maintaining electrical isolation.

Overall, the transformer is a passive device that works on the principle of electromagnetic induction to transfer energy from one circuit to another while maintaining electrical isolation and changing the voltage level.

DIFFERENT TYPES OF TRANSFORMERS

There are several types of transformers, each with a specific purpose and application.

1.  Power transformers: These are used to step-up or step-down the voltage level in power transmission and distribution systems. They are generally large in size and can have a power rating of several megawatts.

1. Power transmission and distribution: Power transformers are used to transfer electrical power from power plants to distribution systems, and to change the voltage level of electricity to match the voltage level of the equipment or transmission line that they are connected to. This helps to reduce the loss of power during transmission and to ensure that power is delivered to the right locations.

2.  Voltage regulation: Step-up and step-down transformers are used to raise or lower voltage levels in electrical power systems. They are used to transfer electricity over long distances and to change the voltage level of electricity to match the voltage level of the equipment or transmission line that they are connected to. This helps to increase the efficiency of the electrical power systems by reducing power loss during the transmission and distribution of electricity.

3. Measuring voltage and current: Instrument transformers, such as current and potential transformers, are used to measure voltage and current in electrical power systems. They are typically used to measure high voltages and currents, such as those found in power transmission and distribution systems.

4.    Isolating equipment: Isolation transformers are used to isolate electrical equipment from the power source. They are designed to transfer electrical power from one circuit to another while providing electrical isolation between the primary and secondary windings. This helps to prevent electrical shock, power surges, and other electrical hazards.

1.   Efficiency: Transformers are highly efficient devices, with typical efficiency levels of up to 99%. This means that very little energy is lost as heat during operation.

2. Durability: Transformers are typically built to last for many years and require minimal maintenance.

3.   Safety: Transformers are designed to be safe devices that do not pose a significant risk of electrical shock or fire.

4. Cost-effective: Transformers are relatively inexpensive devices and are widely available.

5.  Flexibility: Transformers can be used in a wide range of applications and are available in many different sizes and designs.

6.  Voltage level adjustment: They can adjust the voltage level to match the voltage level of the equipment or transmission line that they are connected to.

1.  Size and weight: Some types of transformers, such as power transformers, can be large and heavy, which can make them difficult to transport and install.

2.   Limited isolation: Transformers are not able to completely isolate the primary and secondary circuits, which can make them less suitable for applications where isolation is required.

3. Environmental impact: Some types of transformers, such as oil-immersed transformers, can pose an environmental risk in case of leakage.

4. Cost of maintenance: Some types of transformers require regular maintenance, which can be costly.

5.  Limited power handling capability: Some types of transformers have limited power handling capability, which can make them less suitable for applications that require high power levels.

6.   Limited protection against power quality issues: They do not provide protection against power quality issues such as harmonic distortion, voltage sags, and voltage swell.

1.  Oil leakage: Oil-immersed transformers use oil as a cooling and insulating medium, and leaks or spills can occur, which can have a negative impact on the environment. Oil spills can contaminate soil and water, harm wildlife, and damage ecosystems.

2. PCBs (polychlorinated biphenyls): Many older transformers were filled with PCBs, which are toxic and persistent organic pollutants that can have a negative impact on human health and the environment.

3.  Noise pollution: Transformers can generate significant noise levels, which can be disruptive to wildlife and affect the quality of life for people living or working near transformer stations.

4.   Greenhouse gas emissions: The production, transport, and disposal of transformers can result in the release of greenhouse gases, which contribute to climate change.

1. Proper installation: Transformers should be installed by the manufacturer's instructions and local electrical codes. This includes ensuring that the transformer is properly grounded, that the transformer is properly ventilated, and that the transformer is located in a safe and accessible location.

2. Proper ventilation: Transformers generate heat during operation and proper ventilation is needed to dissipate this heat and prevent overheating. This includes ensuring that the transformer has proper airflow and that the transformer is located in a well-ventilated area.

3.    Regular inspections: Transformers should be inspected regularly for signs of wear, damage, or deterioration. This includes checking for leaks or spills, checking the condition of the transformer's cooling system, and checking the transformer's connections and terminals.

4.  Proper maintenance: Transformers should be maintained by the manufacturer's instructions and local electrical codes. This includes regular oil changes, cleaning the transformer, and checking the transformer's connections and terminals.

5.  Personal protective equipment: Personnel working with or near transformers should wear personal protective equipment (PPE) to protect themselves from electrical hazards. This includes wearing rubber gloves, safety glasses, and hard hats.

6.    Safety labeling: Transformers should be properly labeled with safety information, such as warning labels, to alert personnel to potential hazards.

7.   Emergency procedures: Emergency procedures should be in place for dealing with transformer failures, fires, and other emergency situations. This includes having fire extinguishers.