Isolation transformers belong to safe power sources, generally used for machine maintenance and servicing, providing protection, lightning protection, and filtering functions.
The principle of an isolation transformer is the same as that of a regular transformer. Both utilize the principle of electromagnetic induction. An isolation transformer generally (but not always) refers to a 1:1 transformer. Since the secondary is not connected to the ground, there is no potential difference between any wire of the secondary and the ground, making it safe to use. It is commonly used as a maintenance power supply.
Control transformers and power supplies for electronic tube devices are also isolation transformers. For example, power supplies for electronic tube amplifiers, electronic tube radios, oscilloscopes, and lathe control transformers are all isolation transformers. For safe maintenance of color TVs, a 1:1 isolation transformer is often used. It is also used in air conditioning.
First, the AC power supply we usually use has one wire connected to the ground, and there is a 220V potential difference between the other wire and the ground. Touching it can cause electric shock. However, the secondary of the isolation transformer is not connected to the ground, and there is no potential difference between any two wires and the ground. Touching any wire will not cause electric shock, making it relatively safe.
Secondly, the output side of the isolation transformer is completely "disconnected" from the input side, which effectively filters the input side (the power supply voltage provided by the grid). This provides clean power supply voltage to the electrical equipment.
Another use is to prevent interference. It can be widely used in subways, high-rise buildings, airports, stations, docks, industrial and mining enterprises, and tunnels for power distribution.
An isolation transformer refers to a transformer where the input winding and output winding are electrically isolated from each other, to avoid the danger of accidentally touching live parts (or metal components that may be live due to insulation failure) and the ground. Its principle is the same as that of a regular dry transformer, also utilizing the principle of electromagnetic induction, mainly isolating the primary power circuit, with the secondary circuit floating with respect to the ground to ensure electrical safety.
Function
The main function of an isolation transformer is to completely insulate the electrical connection between the primary and secondary sides, thus isolating the circuit. Additionally, utilizing the characteristic of high-frequency loss in its core, it suppresses high-frequency noise from entering the control circuit. Using an isolation transformer allows the secondary to float with respect to the ground, which can only be used in situations with a smaller power supply range and shorter lines. At this time, the ground capacitance current of the system is too small to cause harm to a person. Another very important function is to protect personal safety! Isolate dangerous voltages.
With the continuous development of power systems, transformers play an increasingly important role as key devices in power systems, and their safe operation directly relates to the reliability of the entire power system. Transformer coil deformation refers to the axial and radial dimensional changes, body displacement, and coil distortion that occur after the coil is subjected to force. The main causes of transformer coil deformation are two: one is that during operation, the transformer inevitably suffers external short-circuit fault impacts; the other is accidental collisions during transportation and hoisting.
Power
The magnetic flux in the transformer core is related to the applied voltage. The excitation current in the current does not increase with the increase in load. Although the load increases, the core will not saturate, which will increase the resistance loss of the coil. If the heat generated by the coil exceeds the rated capacity and cannot be dissipated in time, the coil will be damaged. If the coil is made of superconducting material, the increase in current will not cause heating, but there is still leakage magnetic impedance inside the transformer. As the current increases, the output voltage will drop; the larger the current, the lower the output voltage. Therefore, the output power of the transformer cannot be infinite. If the transformer had no impedance, then when current flows through the transformer, it would generate a very large electromagnetic force, easily damaging the transformer coil. Although the power is infinite, it cannot be used. It can only be said that with the development of superconducting materials and core materials, the output power of transformers of the same volume or weight will increase, but it is not infinite!