Current transformer short circuit

Detailed classification of bushing current transformer cores   1 Classification by purpose   1) Current transformer core (or current transformer measuring winding): Provide grid current information to measuring and metering devices within the normal voltage range.   2) Protection current transformer (or current transformer protection winding): Provide grid fault current information to relay protection and other devices under grid fault conditions.   2 Classification by insulation medium   1) Dry current transformer core: Insulated by ordinary insulating materials treated with varnish.   2) Cast insulated current transformer: Current transformer cast with epoxy resin or other resin mixed materials   3) Oil-immersed current transformer: Insulated by insulating paper and insulating oil, generally outdoor type, currently commonly used in my country at voltage levels.   4) Gas insulated current transformer: The main insulation is composed of SF6 gas. 3 According to the current conversion principle   1) Electromagnetic current transformer: a current transformer that converts current in time according to the principle of electromagnetic induction.   2) Photoelectric current transformer: a current transformer that realizes current conversion through the principle of photoelectric conversion.   4 According to the installation method   1) Through-type current transformer: a current transformer used to pass through a screen or wall.   2) Pillar current transformer: a current transformer installed on a plane or pillar and used as a primary circuit conductor pillar;   3) Bushing current transformer: a current transformer that has no primary conductor and primary insulation and is directly sheathed on an insulating bushing.   4) Busbar current transformer: a current transformer that has no primary conductor but has primary insulation and is directly sheathed on the busbar. 5 According to the number of turns of the primary winding   1) Single-turn current transformer: single-turn current transformers are commonly used for large current transformers.   2) Multi-turn current transformer: Multi-turn current transformers are commonly used for medium and small current transformers.   6 Classification by the location of the secondary winding   1) Upright type: The secondary winding is at the bottom of the product, which is a commonly used structural form in China.   2) Inverted type: The secondary winding is at the head of the product, which is a relatively new structural form in recent years.   7 Classification by current ratio   1) Single current ratio current transformer: That is, the number of turns of the primary and secondary windings is fixed, the current ratio cannot be changed, and only one current ratio conversion can be achieved.   2) Multi-current ratio current transformer: That is, the number of turns of the primary or secondary winding can be changed, the current ratio can be changed, and different current ratio conversions can be achieved;   3) Multiple iron core current transformer: This type of transformer has multiple secondary windings with their own iron cores to meet the needs of different precision measurements and a variety of different relay protection devices. In order to meet the requirements of certain devices, some of the secondary windings have multiple taps. 8 Classification by technical performance of protective current transformer   1) Steady-state characteristic type: guarantee the error of current in steady state, such as P, PR, PX level   2) Transient characteristic type: guarantee the error of current in transient state, such as TPX TPY TPZ TPS level, etc.   9 Classification by use conditions   1) Indoor current transformer: generally used for voltage level of 35KV and below.   2) Outdoor current transformer: generally used for voltage level of 35KV and above.