User external current transformer of pole-mounted circuit breaker

Abstract

The invention relates to a user external current transformer of a pole-mounted circuit breaker, which comprises an iron core, a primary winding, a secondary winding, a primary wire incoming terminal, a primary wire outgoing terminal, a high-voltage insulator, a low-voltage insulator, an insulating column and a secondary lead metal protective sleeve and is in an integrated structure by forming through compound insulation with epoxy resin and silicone rubber, wherein the upper part of the high-voltage insulator is a cuboid, the lower part of the high-voltage insulator is in a shape of a column,the low-voltage insulator is in a shape of a horizontally arranged cylinder and penetrates through and is intersected with the high-voltage insulator, the secondary lead metal protective sleeve is ina shape of L, and threads are arranged at the end of the secondary lead metal protective sleeve. The invention has the advantages of multiple transformation ratios, large application range, convenience in installation, high standard coefficients, high dynamo-thermal stable current, accurate precision, stable insulation, long maintenance period and the like.

Description

technical field [0001] The invention relates to a high-voltage measurement and protection device for a power system, in particular to an outdoor current transformer for a pole-mounted circuit breaker. Background technique [0002] A transformer is a device for measuring current, electric energy or relay protection in a power system. At present, the current transformer used in the pole-mounted circuit breaker of the power system is mainly in the form of a dry coil structure, commonly known as an overcurrent coil, that is, without a primary winding, only The secondary winding is installed inside the circuit breaker box and is set on the primary busbar. During its use, there are mainly the following problems: 1) Because it is a single-turn core, it is only suitable for high-current specifications. Under low-current conditions, the product High-precision measurement and protection cannot be achieved, and the action is unreliable and the sensitivity is poor; 2) Because it is inst...

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Problems solved by technology

[0002] A transformer is a device for measuring current, electric energy or relay protection in a power system. At present, the current transformer used in the pole-mounted circuit breaker of the power system is mainly in the form of a dry coil structure, commonly known as an overcurrent coil, that is, without a primary winding, only The secondary winding is installed inside the circuit breaker box and is set on the primary busbar. During its use, there are mainly the following problems: 1) Because it is a single-turn core, it is only suitable for high-current specifications. High-precision measurement and protection cannot be realized, and the action is unreliable and the sensitivity is poor; 2) Because it is installed inside the box, the busbar of the package needs to be insulated separately, which not only increases the space of the box, but also has a great insulation hidden danger; 3 ) can only be made into a single variable ratio structure. Compared with the circuit breaker on the pole, its application range is limited. After the line is modified or the system is increased, the circuit breaker or transformer needs to be replaced, which increases a lot of material or human investment. , which greatly restricts the development needs of the power system, and is also a problem that needs to be solved in the technical innovation and transformation of the pole-mounted circuit breaker in the power system

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