What are the types of power transformers? What is the function and function?

Power transformer is an electrical device used to change the magnitude of AC voltage. According to the principle of electromagnetic induction, it exchanges one level of AC voltage into another level of AC voltage to meet the needs of different loads. Therefore, transformer plays a very important role in power system and power supply and consumption system. In order to improve your understanding of power transformers, the following is the classification, functions and functions of power transformers compiled by the author, hoping to give you reference and help.

What are the types of power transformers? What is the function and function?

1. Power transformer

The power transformer is mainly used to couple electric energy from the power line to the circuit system, or to one or more components of the system. The power transformer used with solid-state circuit is called rectifier transformer. The rating of the power transformer is given according to the maximum voltage and current transmission capacity of the secondary.

2. Distribution transformer

Pole-type distribution transformer is used to provide relatively small amount of power to residential buildings. It is used at the end of the power utility transmission system.

3. Autotransformer

Autotransformer is a special type of power transformer. It is composed of a single continuous winding and tapped at one side to provide step-up or step-down functions. This is different from the traditional double winding transformer, where the primary and secondary are completely isolated from each other, but magnetically connected through a common core. The windings of the autotransformer are electrically interconnected and magnetically interconnected.

Autotransformers are initially cheaper than two-winding transformers of similar ratings. It also has better regulation (smaller voltage drop) and higher efficiency. In addition, it can also be used to obtain the neutral line of three-wire 240/120 V service, just like the secondary of double-winding transformer. Autotransformer is considered unsafe to use in common distribution circuit. This is because the high-voltage primary circuit is directly connected to the low-voltage secondary circuit.

4. Isolation transformer

Isolation transformer is a very unique transformer. Its turn ratio is 1:1. Therefore, it will not raise or lower the voltage. Instead, it is used as a safety device. It is used to isolate the grounding conductor of the power line from any part of the chassis or circuit load. If the contact is made on the secondary winding of the transformer, the use of the isolation transformer will not reduce the danger or electric shock.

Technically, any real transformer, whether used for signal transmission or power supply, is isolated, because the primary and secondary are not connected by conductors, but by induction. However, only transformers whose main purpose is to isolate the circuit (as opposed to the function of more common voltage conversion transformers) are often referred to as isolation transformers.

5. Instrument transformer

In order to measure the high value of current or voltage, it is better to use the standard low-range measuring instrument together with the specially constructed transformer (also known as the precision ratio transformer). As the name implies, the role of accurate ratio transformer. It converts at an accurate rate, allowing the connected instrument to measure current or voltage without actually running full power through the instrument. A relatively small amount of power needs to be converted, because its only load (called load) is the precise moving element of ammeter, voltmeter or wattmeter.

Function and function of power transformer

Power transformer is one of the main equipment in power plants and substations. The role of transformer is multifaceted. It can not only raise the voltage to send electric energy to the power consumption area, but also reduce the voltage to the use voltage at all levels to meet the needs of power consumption. In short, the step-up and step-down must be completed by the transformer. In the process of transmitting electric energy in the power system, voltage and power losses will inevitably occur. When transmitting the same power, the voltage loss is inversely proportional to the voltage, and the power loss is inversely proportional to the square of the voltage. The transformer is used to increase the voltage and reduce the power transmission loss.

The transformer is composed of two or more coil windings wound on the same iron core. The windings are connected by alternating magnetic field and work according to the principle of electromagnetic induction. The installation position of transformer shall be convenient for operation, maintenance and transportation, and safe and reliable place shall be selected. When using the transformer, the rated capacity of the transformer must be reasonably selected. Large reactive power is required for no-load operation of transformer. These reactive power shall be supplied by the power supply system. If the capacity of the transformer is too large, it will not only increase the initial investment, but also make the transformer operate at no load or light load for a long time, which will increase the proportion of no-load loss, reduce the power factor and increase the network loss. This operation is not economical and unreasonable. If the transformer capacity is too small, it will overload the transformer for a long time and easily damage the equipment. Therefore, the rated capacity of transformer should be selected according to the needs of power load, and should not be too large or too small.