What is the principle of current transformer

What is the principle of current transformer

Update:2022-08-19
Summary: A current transformer is a device that converts the direct current flowing in an electrical circuit...
A current transformer is a device that converts the direct current flowing in an electrical circuit into alternating current, which is then used to produce a regulated voltage. It consists of a laminated steel core, a secondary winding, and an insulating material surrounding the windings. The alternating current produces a magnetic field that is at right angles to the flow of the current. The magnetic field is a vital part of current transformers, as they are used in electrical systems that require accurate measurement of voltage and current.
A current transformer is comprised of a primary winding and a secondary winding. The primary winding can be a single flat turn of wire or a heavy-duty wire coil wrapped around the core. The secondary winding is the conductor that carries the current and is connected to the primary winding. The primary winding and secondary winding are connected in series, resulting in an alternating magnetic flux in the core. This alternating magnetic flux causes a secondary current, I2, to flow through the secondary winding. Both of these windings can be used for different purposes.
A current transformer's phasor diagram shows the ratio between the primary and secondary currents. This ratio is commonly referred to as the current ratio. It can be calculated by multiplying the primary and secondary currents by the number of turns on each winding. Once these two variables are known, the current in the current transformer can be determined. The secondary current will have a much smaller impact on the output voltage of the current transformer than the primary winding.
A current transformer is useful for protecting a power supply system from overheating by sending a signal to a relay device. The relay then cuts off the circuit containing the fault. A current transformer for protection is different than a current transformer used for measurement. It must have a large accurate limit coefficient and reliable insulation. It must also have thermal and dynamic stability. Therefore, it's important to choose a current transformer with accurate and reliable information about the alternating currents.
There are two types of current transformers: the window and the bar type. The former type is the most common, with two separate windings with different turns. The latter type is a step-up transformer and has no opposing output. Window-type transformers are similar to wound-type transformers but have a window. The primary winding passes through the center of the window, resulting in an internal discharge sound. It's important to understand the difference between these two types because they work differently.

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Parameters and specification