Blog - ABM AMPER

Transformers are an important part of any electric power system. They perform the key function of transforming voltage and current, which allows for the efficient transmission of electrical energy from the power source to consumers.

Structure and principle of operation of a transformer

A transformer consists of two or more windings, usually made of copper or aluminum, mounted on a magnetic core. One of the windings, usually called the primary, is connected to the power source, while the other winding, known as the secondary, is connected to the consumer.

The principle of operation of a transformer is based on electromagnetic induction. Changes in the current in the primary winding create a magnetic field in the core, which in turn induces a current in the secondary winding. The magnitude of current and voltage in the windings is related to the ratio of the number of windings: when the number of turns in the secondary winding is greater than the number in the primary winding, the voltage increases, and vice versa.

Types of transformers

1. Air transformers: This is the most common type of transformer that has an open design and uses air as an insulating medium between the windings and the core.
2. Oil transformers: These transformers use a special insulating fluid, usually oil, as an insulating medium. They are used in high voltage electrical networks.
3. Dry transformers: This is a modern type of transformer that uses dry insulating materials instead of liquid. They are environmentally friendly and do not require oil maintenance.
4. Vacuum transformers: They use a vacuum as an insulating medium between the windings and the core, which allows for compact and efficient transformers.

Application of transformers

Transformers are used in all areas of the power industry, from long-distance power transmission to powering household appliances in the home. They are an integral part of any power supply network and play a key role in ensuring the reliability and efficiency of power supply.

Transformers are a key element of the electricity system that enables the efficient use and transmission of electrical energy, providing a reliable and stable power supply to all users.

Transformers in 2024

In 2024, transformers continue to play an important role in the modern power industry, adapting to the demands of efficiency, reliability and sustainability. Here are some of the major trends and innovations that can be observed in this industry in 2024:

1. Efficiency and energy loss reduction: In 2024, transformer manufacturers are actively working to develop more efficient models, which reduces energy losses and improves the overall efficiency of power supply systems.
2. Intellectualization and digital technologies: thanks to the development of digital technologies, transformers are becoming increasingly intelligent, capable of monitoring and diagnosing their condition in real time. This allows power system operators to provide more accurate management and maintenance planning.
3. Development of high-voltage power grids: due to the growth of production and the widespread use of renewable energy sources, transformers for high-voltage networks are becoming more popular. This requires the development of technologies to produce more powerful and reliable transformers.
4. Increased use of AC grids: With the development of modern energy saving technologies and electrification of transportation systems, there is a growing demand for AC transformers that are efficient for long-distance power transmission.
5. Sustainability strategies: In 2024, transformer manufacturers are actively implementing sustainability strategies, focusing on the use of renewable materials, reducing emissions, and increasing the environmental sustainability of their products.

Conclusion

Overall, in 2024, the transformer industry will continue to develop towards greater efficiency, intelligence, and sustainability to meet the demands of the modern power generation world.

A circuit breaker is an electrical switch designed to protect an electrical circuit. The main feature of a vacuum circuit breaker is its ability to switch off short-circuit currents.
The requirements for medium and high voltage switches are formulated in the international standards IEC 60694 and IEC 62271-100.
Medium-voltage circuit breakers, like other electromechanical switching devices, differ depending on the medium in which their contacts open and close. There are, in particular, vacuum, oil, gas and air circuit breakers, the first three types being used in AC networks, while air circuit breakers, which were previously used in AC and DC networks, are currently only used in DC networks.
The application of one or another arc suppression medium is determined by its electrophysical properties, as well as by technological and operational factors. The curves presented in Fig. 1a allow comparing the electrical strength of different media, of which air is the worst. Elegas (sulfur hexafluoride) at a pressure close to atmospheric pressure (1 bar ≈ 1 kGs/cm2) has about 2.5 times higher electrical strength. An even better dielectric is transformer oil, which is also used in circuit breakers.
However, transformer oil and gas are considerably inferior to vacuum in terms of electrical strength, with which high-pressure gas (5 bar and more) competes successfully.
Vacuum is the most efficient medium in terms of minimizing the energy released in the arc during its extinguishing (Fig. 1b). Thus, vacuum switching modules or vacuum interrupter chambers have the smallest dimensions. Vacuum circuit breakers are the least demanding in operation.

Vacuum circuit breakers as a type of switching device appeared on the electrical market in the late 1970s. By overcoming the disadvantages of vacuum switching that were discovered during the initial research phase, such as current clipping and associated overvoltages, re-ignition of the arc after the current has passed through zero, welding of contacts during short-circuit currents, the development of suitable contact materials and technical solutions for the design of vacuum interrupters, the production of vacuum circuit breakers began to grow rapidly. Today, in the medium-voltage circuit breaker segment, vacuum circuit breakers occupy approximately 80% of the market, and this figure is on an upward trend.

The vacuum circuit breaker is based on a vacuum chamber, which successfully cuts short-circuit currents of up to 50 kA and ensures arc extinguishing from the first passage of current through zero ( Image 2).

  Vacuum switches are available with both spring-motor and electromagnetic actuators.
Vacuum circuit breakers cover a wide range of applications, from industrial plants to urban infrastructure, where they are used to protect and control electrical networks. They provide high operational reliability and safety, minimizing the risk of accidents and facilitating network maintenance.
Vacuum circuit breakers from AVM Ampere utilize a spring-motor drive design with two-stage contact separation.

1 – fixed contact, 2 – vacuum chamber, 3 – insulating pole of the switch, 4 – trigger mechanism of the drive, 5 – movable contact, 6 – compression spring, 7 – main drive of the switch, 8 – traction insulator, 9 – drive lever.

The main advantage of the VB4 actuator is high mechanical resistance and a special diagram of power contacts separation. When the circuit breaker is tripped, the contacts are not separated instantaneously, which avoids high level of overvoltages.

The actuator also provides a mechanism for breaking the welded contacts of the vacuum chamber.

      Medium voltage switchgear (from 6 to 40.5 kV) contains equipment designed to transmit and distribute electrical energy. These devices ensure the reliability of power supply, protection against overloads and short circuits.
The range includes metal enclosed  and metal-clad switchgear units designed for use in electrical substations of distribution networks. Modern materials and technologies, such as vacuum circuit breakers and epoxy insulators, as well as automation and remote control systems, increase their safety and efficiency.

      The use of metal-clad switchgear of the VM-1 series allows achieving high reliability of power supply, ensures safe operation and maintenance, and provides for the possibility of substation automation and integration into intelligent power grid management systems (SCADA). This makes them an important element of the energy infrastructure that helps to improve the reliability of power supply.

When selecting switchgear, it is important to take into account technical requirements and operating conditions to ensure an optimal cost-effectiveness ratio and compliance with safety standards. For networks designed for small currents and low short-circuit currents, it is recommended to use metal enclosed unit KZO-205 seriess. Low cost combined with high operational safety makes KZO-205 cells the best choice for secondary distribution.

ABM Amper also produces a wide range of specialized switchgear, such as pit and mine switchgears, as well as electric transport traction substations.

All metal enlosed switchgear from ABM Amper are passed all type tests with European standards EN\IEC 62271-1, EN\IEC 62271-200, which is confirmed by the relevant standard test reports.