Regarding the current transformer, it is a kind of important power component near the power system. Its function is to convert the large current on the primary high voltage side into the secondary current through the alternating magnetic process. Maintenance, measurement, wave recording, Calculate the degree and so on. For example: the secondary rated current of the current transformer used is 5A, that is, it is marked as 100/5, 200/5, etc. on the nameplate, indicating that if there is a current of 100A or 200A on the primary side, the current converted to the secondary side is 5A. There are many types of current transformers. The following four aspects are used to classify current transformers:

One, according to the current transformer according to the principle of current change:

Electromagnetic current transformer: a current transformer that completes current conversion according to the principle of electromagnetic induction;

Photoelectric current transformer: The current transformer that has undergone the principle of photoelectric conversion to complete the current conversion is still under development.

Second, according to the current transformer according to the insulation medium:

Gas insulated current transformer: The main insulation is composed of gas.

Dry-type current transformer: general insulating material is dipped in varnish as insulation;

Pouring current transformer: a current transformer molded with epoxy resin or other resin mixed materials;

Oil-immersed current transformer: insulated by insulating paper and insulating oil, generally outdoor type. At present, various voltage levels are commonly used in our country;

Three, according to the current transformer according to the installation method:

Through-type current transformer: a current transformer used to pass through the screen or the wall;

Pillar type current transformer: Installed on a plane or pillar, and used as a current transformer for the primary circuit conductor pillar;

Bushing type current transformer: a current transformer without primary conductor and primary insulation, directly sleeved on the insulated bushing;

Bus-type current transformer: A current transformer that has no primary conductor but primary insulation and is directly used on the bus.

Active electronic current transformer is characterized by the primary sensor is a hollow coil, and the high-voltage side electronic components need to be powered by the power supply to operate. The passive magneto-optical glass type electronic current transformer is characterized by the primary sensor is magneto-optical glass and no power supply is required. powered by.

Four. According to the purpose:

Maintenance current transformers (or maintenance windings of current transformers. When the power grid is faulty, the power grid fault current information is provided to equipment such as relay maintenance.

Measuring current transformers (or measuring windings of current transformers. Within the normal operating current range, supply current information of the power grid to measuring and metering equipment;

In addition, it can be classified according to the insulation type of the winding and the structure of the iron core.