The electricity that we receive in our homes is produced in major proportions in the electrical grid that sends electricity over vast areas through power lines. However, the wires used in power lines are not good electrical conductors; and these imperfections resist the flow of electrical current. This results in loss of electrical power over longer power lines. To resolve this, step-up transformers are used to raise the voltage produced to a higher value, thus enabling power to travel longer distances effectively without loss of power. In this way, step-up transformers help in supplying power to transmission lines; but this high voltage of electricity cannot be used by the end users. Such high power can not only damage the appliances, but can also cause hazards and death. This is why the voltage needs to be decreased again before being sent to the end customers. Step-down transformers are therefore used at substations, and also on the utility poles near buildings, so that the voltage is lowered and current is increased by the time the power reaches the end users. In this way, both step-up and step-down transformers play important roles in bringing in acceptable amount of power in homes and offices for our everyday usage. These step-up and step-down transformers are the main classifications of power transformers. However, depending upon the construction and purpose, power transformers in India are classified into many other groups, which are as follows.
Step-up and step-down transformers
As the names suggest, step-up and step-down transformers increase and decrease the voltage level of power produced respectively to distribute power throughout the power distribution network. The biggest example of using step-up and step-down transformers is in the power grid system right from the electrical grid to the utility poles.
Single-phase and three-phase transformers
Again as the name suggests, single-phase transformers accept single-phase AC current to transfer energy from one circuit to another through electromagnetic induction. Conversely, three-phase transformers have three primary windings connected together and three secondary windings connected together to provide economical solutions for supplying large loads and large power distributions. These transformers are used in supplying power to various applications within residential and commercial equipment like televisions, home inverters, lighting, heating equipment, and low voltage electronic devices.
These are doughnut-shaped transformers that are smaller, save space, and have reduced external magnetic field. With a ring-shaped core and copper windings wrapped around the ring, there is no residual gap in the magnetic path, which makes these transformers highly efficient, generating very low off-load losses, and exhibiting higher inrush current. Toroidal transformers are used in current switches, disconnectors, capacitors, and other related power devices.
Isolation transformers are those that link two circuits magnetically, while providing zero metallic conductive path between them. This helps to prevent coupling of electromagnetic noise and leakage from AC power system into the appliances. The best usage of these transformers is in medical equipment.
Autotransformers are those that have one winding tapped at a point along the winding, wherein voltage is applied in one portion, and a higher/lower voltage is produced in the other portion. These transformers are used where the ratio between high voltage and low voltage is lesser than 2. Autotransformers are smaller, lighter, cheaper, and more efficient. They are used in induction motors, electrical apparatus in testing labs, and as boosters in AC feeders.
You can get all of these power transformers in India and more at Miracle Electronics, where transformers are designed to provide the highest level of safety to the operator by regulating and stepping up/down voltages as required. Miracle Electronics’ power transformers are RoHS compliant, REACH compliant, and available with CE and UL marks on request.