Ratio of transformation adjustable type current transformer and data collecting method thereof

Abstract

The invention relates to a ratio of transformation adjustable type current transformer and a data collecting method thereof. A secondary winding of a first core-through type current transformer comprises a first tap, a tail tap and at least one center tap; a primary winding forms a first ratio of transformation with a winding between the first tap and the tail tap of the second winding, the primary winding forms a second ratio of transformation with a winding between the first tap and the center tap of the second winding, the primary winding forms a third ratio of transformation with a winding between the center tap and the tail tap of the second winding, and so on; the ratio of transformation adjustable type current transformer further comprises a second core-through type current transformer which has the same structure as the first core-through type current transformer. The ratio of transformation adjustable type current transformer has the beneficial effect that the multi-stage ratio of transformation adjusting of the current transformer in the application process is realized, so as to solve the problems of the traditional power distribution automatic system that when the load of the measured circuit exceeds the measurable range of the fixed-ratio of transformation transformer for a long time, the measuring error is larger, and the other new transformer with the matched ratio of transformation needs to be replaced under the extreme condition.

Description

technical field [0001] The invention relates to the technical field of power system distribution automation, in particular to a variable ratio adjustable current transformer and a data acquisition method thereof. Background technique [0002] In the known collection and measurement methods, the distribution network system with a voltage level of 10kV and below mainly uses current transformers with fixed ratios to collect and measure data through intelligent distribution terminals, and according to the measurement and protection functions of distribution lines Generally, a transformer with a transformation ratio is used, and this transformer is compatible with the collection of measurement and protection functions. This measurement method mainly has the following defects: [0003] 1. The cost of design and application is relatively high, and it is necessary to repeatedly correct the two functions of measurement and protection and specific product characteristics and select c...

AI Technical Summary

Problems solved by technology

[0003] 1. The cost of design and application is relatively high, and it is necessary to repeatedly correct the two functions of measurement and protection and specific product characteristics and select compatible parameters, including the determination of the transformation ratio, and the effect of this design will appear in three situations: one is to take into account Protection transformation ratio and parameter selection, the protection has a better function of collecting fault information, but the measurement accuracy will be further reduced due to the inappropriate transformation ratio; the second is to take into account the measurement transformation ratio, the measurement is accurate, and the protection signal extraction is further sensitive due to the inappropriate transformation ratio. The third is to give consideration to both, but ordinary transformers cannot achieve

In the application, both the first two are selected, which may easily cause misjudgment or missed judgment of the operating conditions in the actual system application

[0004] 2. After one-time installation, when the load changes greatly, or due to the increase of user load, or due to the load moving out, the fixed ratio transformer cannot adapt to this change, if it exceeds the measurable range of its fixed ratio transformer It will cause a decrease in measurement accuracy, which will not be able to effectively meet the measurement accuracy requirements of the distribution automation system in the long run, reducing the timeliness and accuracy of the distribution automation system operation monitoring

In this case, we can only replace the transformer with a new one to re-determine the transformation ratio. This method is not only labor-intensive, but also troublesome to disassemble and assemble. It also needs to be redesigned and requires a long-term power outage, which increases the power outage cost for the enterprise.

[0005] 3. Due to the unstable power load of some customers or regions at present, with large ups and downs, some enterprises adjust production according to market changes, and changes in power load in rural areas due to seasonal changes make the operation of distribution network lines The timeliness and accuracy of monitoring are reduced. If some key stations are seasonally replaced with current transformers with different transformation ratios, it is impossible to operate in reality and is unrealistic.

Therefore, the use of fixed ratio transformers generally has poor accuracy in this case.

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