CN2284443Y

CN2284443Y - Current transformer

Info

Publication number: CN2284443Y
Application number: CN 96246210
Authority: CN
Inventors: 赵学农
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-12-30
Filing date: 1996-12-30
Publication date: 1998-06-17
Anticipated expiration: 2006-12-30

Abstract

The utility model discloses a current mutual inductor used for an electric power system, mainly comprising an expander, an oil conservator, a ceramic sleeve, a primary winding, a secondary winding, and a base. The secondary winding comprises two windings used for protecting a relay and a winding used for measuring, wherein, the secondary winding further comprises a winding specially used for metering. The winding specially used for metering is provided with two iron cores which are mutually in parallel. Coils of the winding specially used for metering wind on two iron cores which are mutually independent. The utility model adopts the two iron cores of the winding specially used for metering to improve the excitation characteristic, with reduction of excitation current, error rate, and security factor (FS not more than 10). Metering devices are prevented from being impacted when faults happen to an electric power system, thus, the service life of the metering devices is extended.

Description

The monologue story-telling with gestures current transformer

The utility model relates to a kind of current transformer that is applied in the electric power system.

Current transformer is relay protection of power system and measures indispensable device.Whether accurate measurement is directly connected to power supply department and user's interests.In order to improve measuring accuracy, the level that should improve measuring instrument is inferior, improve simultaneously the level time (error that is current transformer is little) of current transformer again, when electric power system is broken down, the level time high more (error rate is more little) of current transformer, its secondary current increases big more suddenly, and the instrument of measuring through instrument transformer is hit also very big.It would be desirable that like this current transformer error is little, when electric power system was broken down, the multiple that its secondary current increases will lack, and this point is weighed with safety coefficient.China's its error rate of estimated current instrument transformer is ± 0.5, and safety coefficient is FS15 (as a LCWB5-66 type current transformer).Because the measurement winding in its secondary winding of this kind current transformer is single core structure, want to reduce its error rate, the increase core section is long-pending can to reduce error, but safety coefficient is also strengthened, like this when electric power system is broken down, measuring instrument is hit also just big more, has a strong impact on metering instrument precision and useful life.

At the deficiency that above-mentioned prior art exists, the purpose of this utility model provides and a kind ofly both can reduce error rate, can reduce the current transformer of safety coefficient again, the useful life that makes it to improve measuring accuracy and instrument.

The purpose of this utility model is achieved in that it includes expander, oil conservator, insulator, winding, secondary winding and a base; comprise two used for relay protection windings and a measurement winding in the secondary winding; it is characterized in that: comprise further that is also specialized in a metering winding; this metering is provided with two mutual iron cores arranged side by side with winding, and metering is wrapped on two separate iron cores with winding coil.

The utility model has the advantages that: utilize metering to improve excitatory characteristic with the double-iron core of winding, both can reduce exciting curent, reduce error rate, can reduce safety coefficient (FS＜10) again, make it when metering is broken down in electric power system, to prevent that instrument from being impacted, thereby improve the useful life of measuring instrument.

Below in conjunction with accompanying drawing the utility model is explained.

Fig. 1 is the utility model structural representation.

Fig. 2 is the secondary winding structural representation.

Fig. 3 is the utility model electrical schematic diagram.

By accompanying drawing as can be known, the utility model mainly is made of expander 1, oil conservator 2, insulator 3, winding 4 (L1, L2), secondary winding 5 and a base 6.Wherein secondary winding 5 comprises insulating barrier 5-1, two used for relay protection winding 5-2 (3K1,3K2), 5-3 (4K1-4K2) and measurement winding 5-4 (2K1-2K3), a metering winding 5-5 (1K1-1K3).Measure and to connect some indicating instruments, monitor as electrical operation and use with winding 5-4.Winding 5-5 use in metering, is used for separately measuring, and this winding coil is wrapped on two mutual arranged side by side and separate iron core 5-6, the 5-7, and the number of turn that coil twines on two iron cores does not wait, in the number of turn that twines on the iron core 5-6 more than the number of turn that on iron core 5-7, twines.The sectional area of iron core 5-7 is 1-10 a times of iron core 5-6 sectional area, measure the centre tap 2K2 that uses among the winding 5-4 and measure the centre tap 1K2 that uses among the winding 5-5, its effect is to enlarge electrorheological to compare scope, 1K1,1K3 and 2K1,2K3 are respectively metering winding and the measurement binding posts of the full circle current ratio of winding, and 1K1,1K2 and 2K1,2K2 are respectively the tap current ratio of winding is used in metering with winding and measurement binding posts.

Claims

1, a kind of current transformer that is applied in the electric power system; it includes expander, oil conservator, insulator, winding, secondary winding and a base; comprise two used for relay protection windings and a measurement winding in the secondary winding; it is characterized in that: comprise further that is also specialized in a metering winding; this metering is provided with two mutual iron cores arranged side by side with winding, and metering is wrapped on two separate iron cores with winding coil.