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Transformer is an important equipment used in power system. Its main function is to change the voltage level to adapt to different power transmission and use requirements. Transformer is widely used in power generation, transmission and distribution systems to ensure the effective transmission and utilization of electric energy. The following is a detailed introduction to the role, composition and working principle of transformer.
A. The role of transformer
a. Voltage conversion: The most basic function of transformer is to convert high voltage electric energy into low voltage electric energy, or to increase low voltage electric energy to high voltage electric energy. In power transmission, high voltage is usually used to reduce line loss, while when using it, the voltage needs to be reduced to a safe and applicable level.
b. Power distribution: Transformer can distribute electricity from power station to various users. Through transformer, users in different regions and different loads can get the required electric energy.
c. Isolation function: Transformer can electrically isolate the high voltage side from the low voltage side, which plays a role in protecting the safety of equipment and personnel. In some applications, such as medical equipment, isolation transformer is particularly important.
d. Improve grid stability: By adjusting the voltage level, transformer helps to improve the stability of power system, balance grid load and reduce voltage fluctuation.
B. Composition of transformer
The transformer is mainly composed of the following parts:
a. Iron core: The iron core is the core part of the transformer, usually made of silicon steel sheets, with the purpose of providing a good magnetic circuit to reduce energy loss. The shape and material of the iron core directly affect the performance of the transformer.
b. Winding: The transformer has two windings, namely the primary winding and the secondary winding. The primary winding is connected to the input power supply, and the secondary winding is connected to the load. The winding is usually made of copper or aluminum wire to achieve the transfer of electrical energy.
c. Insulation material: In order to prevent short circuit and leakage, insulating materials are required between the winding and the iron core. Common insulating materials include paper, oil and plastic.
d. Cooling system: During operation, the transformer generates heat, so a cooling system is required to maintain its normal operating temperature. Common cooling methods include natural air cooling and oil cooling.
e. Protection device: The transformer is usually equipped with various protection devices, such as fuses, relays and temperature sensors, to prevent faults such as overload and short circuit.
C. Working principle of transformer
The working principle of transformer is based on the law of electromagnetic induction. When AC current passes through the primary winding, an alternating magnetic field is generated in the iron core. This alternating magnetic field induces current in the secondary winding.
The specific process is as follows:
a. Alternating current generates magnetic field: When AC current passes through the primary winding, an alternating magnetic field is generated around the winding.
b. Magnetic flux coupling: This alternating magnetic field propagates through the iron core and forms a magnetic flux in the secondary winding.
c. Electromagnetic induction: According to Faraday's law of electromagnetic induction, the change of magnetic flux induces electromotive force (voltage) in the secondary winding. The magnitude of this induced voltage is related to the turns ratio (i.e., transformation ratio) of the primary and secondary windings.
d. Energy transfer: The electric energy input by the primary winding is transferred to the secondary winding through the magnetic field to form output electric energy.
Its simple and effective working principle makes the transformer an indispensable part of the modern power system.
