Origins of transformers
In our previous blog, we discussed the history of the light bulb and how it evolved with time; in today’s blog, we will discuss the brief history of the Transformer. The topics will be: What is a Transformer? The first Transformer is a ring-shaped transformer, a block-shaped class of transformer, a transformer in service, a dryformer, and a power transformer.
What is a Transformer?
A transformer is a device that transfers energy from one circuit to another. We can always figure this much working from its name itself.
The transformers are used to bring the voltage up or down (increase or decrease the voltage level).
However, the transformer principle depends on the mutual induction between inductively coupled coils or two circuits linked by common magnetic flux.
The first Transformer
We all know the famous scientist Michael Faraday and his laws. So we will see here how exactly Michael Faraday got the idea of the first transformer and through which experiment.
On 29th August 1831, Faraday made the first breakthrough in producing electricity from magnetic. He had conducted a series of experiments to demonstrate electromagnetic induction.
Experimental setup
I’ll try to narrate the experimental setup for you for the design; he took a soft iron ring around half the circumference and called it to side A and wounded three coils of wire on the other side, called it side B.
Side B is separated from side A by some distance. But, of course, to check the electromagnetic induction, He has to keep them apart. So, he wound the wire in two separate coils in the same direction as the former winding.
Two coils are connected on side B in series and carry the connecting wire connected to a magnetic needle. Then, one side A coiled to the battery and closed the circuit on side A.
The magnetic needle on side B sensed the current flowing on side A; after oscillating, it returned to its original place. A further disturbance occurs only when the connection on the other side A is broken. Still, this time, the oscillation was done in the opposite direction.
This momentary disturbance of the magnetic needle was demonstrated as electromagnetic induction.
The apparatus designed by Faraday was to study the only cause of DC current when AC current was not even invented. However, that experiment was also used to study the DC coil’s magnetic field, causing the induced voltage in another coil.
Faraday’s findings
During his experiments, Faraday found that whenever we wound a coil of wire around a piece of iron, it would convert into a magnet after passing the current. If this magnet is inserted into another coil of wire, and after connecting a galvanometer to the terminals of the second coil, the galvanometer will definitely show the deflection.
Faraday was the first to invent the principle and design of the transformer. He invented the basic elements like two independent coils and a closed iron core.
What is the oldest transformer?
In the late 19th century, the world witnessed a transformative period in electrical engineering. Innovators were exploring ways to efficiently generate, transmit, and utilize electrical power. One of the most significant breakthroughs during this time was the development of the transformer.
In 1885, three pioneering engineers, Ottó Bláthy, Miksa Déri, and Károly Zipernowsky, working at the Ganz Works in Budapest, Hungary, unveiled a revolutionary electrical system. Their system featured an essential component: the transformer. This transformer was designed to step up or step down voltage levels, allowing for efficient transmission and distribution of electrical power.
The transformer built by Bláthy, Déri, and Zipernowsky was not just any transformer; it was part of a groundbreaking project to power the Vienna International Exposition of 1885. This exposition served as a platform to showcase the latest advancements in technology and innovation, and the electrical system designed by the Hungarian engineers was at the forefront of this display.
The transformer played a pivotal role in the success of the electrical system. The system could efficiently transmit electricity over long distances by employing alternating current (AC) electricity and utilizing transformers to adjust voltage levels. This marked a significant departure from the limitations of direct current (DC) systems, which struggled with long-distance transmission.
The Installation of the Transformer
The installation of this transformer represented a turning point in the history of electrical engineering. It demonstrated the feasibility and advantages of AC electricity for widespread distribution. The efficiency and reliability of the system showcased the potential for a new era in electrical power generation and utilization.
Over a century later, the transformer built by Bláthy, Déri, and Zipernowsky stands as a testament to their ingenuity and foresight. Despite its age, it remains operational, symbolizing the enduring impact of its innovation on the modern world. This transformer paved the way for developing electrical grids that power our cities, industries, and homes today.
In conclusion, the transformer installed by Ottó Bláthy, Miksa Déri, and Károly Zipernowsky in 1885 represents a landmark achievement in electrical engineering. Its role in powering the Vienna International Exposition of 1885 and its lasting legacy as one of the oldest transformers still in operation make it a cornerstone of electrical technology and innovation.
The next 50 years of evolution of the Transformer (1832-1882)
Many years after the discovery of Faraday, there was no practical value for induction coils rather than using them only to produce higher voltage than the galvanic batteries.
In 1832, Joseph Henry invented self-inductance.
He noticed that the current interruption to very high voltage is induced by rapid flux change.
The coils designed then were made of copper strips wrapped in silk insulation.
Joseph Henry was not the only one who made observations on this topic. Many scientists have experimented with Henry’s experiment, building induction coils with interrupted direct currents to give shocks or sparks.
On this theory, spark inductors were developed, which are now a day known as high voltage pulse transformers regarded as DC device
The development of spark inductors promoted the construction of the transformer.
In 1853, Heinrich Daniel Ruhmkorff increased the spark length by improving the vibrator and insulation and introducing a new coil type.
Faraday’s and Ruhmkorff coils are two different types of coil used in two different classes of converters: closed-circuit and open-circuit transformers, respectively.
In the Ruhmkorff type, the transformer is constructed with a straight core. It had to complete the circuit through the air, so there was no magnetic coupling and magnetic circuit present; hence, this type of transformer is also called an open transformer.
The disadvantage of using these transformers was that their losses were very high as no magnetic path was present.
In Faraday’s type, there was a complete magnetic circuit of iron; hence, they are also called closed transformers. This type of transformer is mostly used back then and nowadays.
Because they are very efficient, the losses are less than an open one.
Aim of Transformer building
By the late 19th century, the aim of transformer builders was:
- To shorten the magnetic circuit as much as possible to increase efficiency.
- Increase the cross-sectional area as much as consistent weight.
- Use iron of greatest permeability (a material’s permeability is its ability to pass the maximum flux). The maximum flux that can pass through high-permeability iron will be the flux linkage and voltage induced in another coil.
Kennedy made the first improvement of the Faraday coil, although the changes were very slight.
Ring-shaped Transformer
In 1885, Károly Zipernowsky and Miksa Déri designed the first ring-shaped transformer. Both were Hungarian electrical engineers.
The electrical design of the ring-shaped transformer was excellent. Still, it was not that sound if we thought mechanically. For example, in the design position
The design of ring transformers’ primary and secondary coils was insulating wounds into a solid core and over the wound with a heavy layer of iron wire.
George Westinghouse acquired American rights under the patent in 1885 and then selected William Stanly to develop a transformer.
After this, William Stanly made the transformer with a ring of finely laminator iron to reduce the eddy current losses.
In the winter of 1885, William Stanley installed the first experimental AC distribution system, which supplied 150 lamps in Barrington, Massachusetts.
In the late 19th century, transformers were 100% efficient, or 97.5%, practically speaking, for a 10KW transformer.
This is the same for today’s transformers. Also, there is no moving part, so these transformers are more efficient than motors.
The first block-shaped class of Transformer
Around the same period, the block-shaped class of transformers was first designed as round-shaped transformers.
The block-shaped transformer coils are entirely surrounded by laminated iron except at their ends. At the same time, the magnetic circuits are comparatively short in direction.
The block-shaped transformer design is such that it is mechanically simple and easy to assemble.
Transformer in service
Transformers have come under the service for various reasons, such as:
There was a problem transmitting electrical energy at high voltage from the generating station to points nearer to the consumer. But using the transformers, one can reduce the voltage and stabilize the voltage at the consumer’s terminal.
Transformers are also used for lightning. The preferred voltage for the lighting system was 50-52V when the secondary circuit length was 100-104V. At that time, the transformer steps down the voltage for economic reasons.
At that time, connections (also known as banking) of the transformer are made according to load.
In 1890, Wisconsin’s national electric manufacturing company manufactured the national transformer. This transformer was a ring type. According to some design specifications, it is surrounded by iron, so all the wire in the transformer is thus active.
In 1892, European manufacturers designed the Ferranti transformer, also known as a converter.
Recent Transformers
Dryformer
Deformers are high-voltage transformer designs that eliminate the need for oil-based using high-voltage cross-linked polyethene (XLPE) power cables or paper in the transformer construction.
This transformer, developed by ABB Company, was the first-ever dry transformer. In 1999, it was delivered to a Swedish utility rating of 20MVA, 140KV/6.6KV.
The best feature of a dry transformer is that it eliminates the risk of contamination of soil, groundwater, and air and minimizes the risk of fire and explosion due to the absence of oil.
Power Transformer
ABB also developed the power transformers, which have the features of a conventional generator plus a step-up transformer.
The high-voltage generator is connected directly to the power network without a step-up transformer.
In this blog, we have only discussed the development of the transformer model so far. Still, each component has been developed in parallel over the years to increase more efficient working capacity and smooth operation.
