Isolation transformers are safe power supplies and are generally used for machine repair and maintenance to protect, prevent lightning, and filter.
The principle of isolation transformer is the same as that of ordinary transformer. They all use the principle of electromagnetic induction. Isolation transformers generally (but not all) refer to 1:1 transformers. Because the secondary is not connected to the earth. There is no potential difference between any secondary line and the ground, so it is safe to use. Often used for maintenance power supply.
The power supply for the control transformer and electronic tube equipment is also an isolation transformer. Power supplies such as tube amplifiers, tube radios and oscilloscopes, and lathe control transformers are all isolation transformers. For example, a 1:1 isolation transformer is commonly used for safe maintenance of color TVs. It is also used in air conditioners.
First of all, we usually use one line of AC power voltage to connect to the ground, and there is a 220V potential difference between the other line and the ground. Human contact can cause electric shock. The secondary of the isolation transformer is not connected to the ground, and there is no potential difference between any two wires of it and the ground. People will not get an electric shock if they touch any line, so it is safer.
Secondly, the output end of the isolation transformer is completely "open circuit" isolated from the input end, so that it effectively filters the input end of the transformer (the power supply voltage supplied by the grid). So as to provide a pure power supply voltage to the electrical equipment.
Another use is to prevent interference. It can be widely used in places such as subways, high-rise buildings, airports, stations, wharfs, industrial and mining enterprises and tunnels for power transmission and distribution.
Isolation transformer refers to a transformer in which the input winding and the output winding are electrically isolated from each other to avoid accidentally touching the live body (or metal parts that may be charged due to insulation damage) and the earth at the same time. Its principle is the same as that of ordinary The dry-type transformer is the same, but also uses the principle of electromagnetic induction to isolate the primary power circuit, and the secondary circuit floats to the ground to ensure the safety of electricity use.
The main function of the isolation transformer is to completely insulate the electrical on the primary side and the secondary side, and also to isolate the circuit. In addition, the high-frequency loss of its iron core is used to prevent high-frequency clutter from being transmitted to the control loop. The isolation transformer is used to suspend the secondary to the ground, which can only be used in occasions with a small power supply range and short lines. At this time, the capacitance current to the ground of the system is too small to cause personal injury. Another very important role is to protect personal safety! Isolate dangerous voltage.
With the continuous development of the power system, the transformer is playing an increasingly important role as a key equipment in the power system. Its safe operation is directly related to the reliability of the entire power system. The deformation of the transformer coil refers to the occurrence of the coil after being stressed. Dimensional changes in the axial and width directions, body displacement, coil distortion, etc. There are two main reasons for the deformation of the transformer coil: one is that the transformer is unavoidably impacted by an external short-circuit fault during operation; the other is that the transformer accidentally collides during transportation and hoisting.
The magnetic flux of the transformer core is related to the applied voltage. The excitation current in the current does not increase with the increase of the load. Although the iron core will not saturate when the load is increased, the resistance loss of the coil will increase. If the rated capacity is exceeded, the heat generated by the coil cannot be dissipated in time, and the coil will be damaged. If the coil is made of superconducting material, the increase in current will not cause heating. However, there is still impedance caused by magnetic leakage inside the transformer. The output voltage will decrease when the current increases. The larger the current, the lower the output voltage, so the output power of the transformer cannot be unlimited. If the transformer has no impedance, then when the current flows through the transformer, it will produce a particularly large electromotive force, which can easily damage the transformer coil. Although the power is unlimited, 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 not infinite!