阅读说明：本技术 一种ct本体二次回路校验方法 (CT body secondary circuit calibration method ) 是由 周亚群 张钢 都劲松 曹浩军 吕尚霖 周昭亮 李静 于 2020-04-13 设计创作，主要内容包括：本发明公开了一种CT本体二次回路校验方法,包括以下步骤：通过CT回路校验工具进行CT本体二次回路的正向加压校验工作；判断CT本体二次回路正向电压的实际幅值及方向与CT回路校验工具的输出电压幅值及方向是否一致,当一致时,则CT回路校验工具进行CT本体二次回路的反向加压校验工作,当不一致时,则查找并消除CT本体二次回路缺陷；判断CT本体二次回路反向电压的实际幅值及方向与CT回路校验工具的输出电压幅值及方向是否一致,当一致时,说明CT本体二次回路接线正确可靠,否则,则查找并消除CT本体二次回路缺陷,该方法能够准确校验CT本体二次回路接线是否正确可靠,且,工作强度较低,校验时间较短。(The invention discloses a CT body secondary circuit checking method, which comprises the following steps: carrying out positive pressurization verification work on a secondary circuit of the CT body by using a CT circuit verification tool; judging whether the actual amplitude and direction of the forward voltage of the CT body secondary circuit are consistent with the amplitude and direction of the output voltage of the CT circuit checking tool or not, if so, performing reverse pressurization checking work on the CT body secondary circuit by the CT circuit checking tool, and if not, searching and eliminating the defects of the CT body secondary circuit; the method can accurately check whether the wiring of the secondary circuit of the CT body is correct and reliable, and has low working intensity and short checking time.)

1. A CT body secondary circuit verification method is characterized by comprising the following steps:

1) carrying out CT body secondary circuit check preparation work;

2) carrying out positive pressurization verification work on a secondary circuit of the CT body by using a CT circuit verification tool;

3) measuring and recording the actual amplitude and direction of the forward voltage of the secondary circuit of the CT body;

4) judging whether the actual amplitude and direction of the forward voltage of the CT body secondary circuit are consistent with the amplitude and direction of the output voltage of the CT circuit checking tool or not, and turning to the step 6) when the actual amplitude and direction of the forward voltage of the CT body secondary circuit are consistent with the amplitude and direction of the output voltage of the CT circuit checking tool, or turning to the step 5) if not;

5) searching and eliminating the defects of the secondary circuit of the CT body, and then turning to the step 2);

6) carrying out reverse pressurization verification work on a secondary circuit of the CT body through a CT circuit verification tool;

7) measuring and recording the actual amplitude and direction of the reverse voltage of the secondary circuit of the CT body;

8) judging whether the actual amplitude and direction of the reverse voltage of the CT body secondary circuit are consistent with the amplitude and direction of the output voltage of the CT circuit checking tool or not, if so, turning to the step 10), otherwise, turning to the step 9);

9) searching and eliminating the defects of the secondary circuit of the CT body, and then turning to the step 6);

10) and finishing the checking of the secondary loop of the CT body.

2. The CT body secondary loop verification method as claimed in claim 1, wherein the specific operation of step 1) is:

101) the CT body to be checked is in an uncharged state;

102) laying and arranging the cables of the secondary circuit from the CT body terminal box to be checked, and wiring the cables of the secondary circuit from the CT body terminal box to the CT body terminal box according to the design drawing;

103) opening the end cover of the terminal box of the CT body, and confirming that the parameters of each group of CT nameplates are consistent with the design parameters;

104) cutting off all current terminal connecting pieces in the CT body terminal box, and thoroughly isolating a CT body secondary loop from an external loop of the CT body terminal box in the CT body terminal box;

105) and manufacturing a CT loop checking tool.

3. The CT body secondary circuit verification method of claim 1, wherein the CT circuit verification tool is composed of dry cell batteries connected in series.

4. The CT body secondary loop verification method as claimed in claim 1, wherein the specific operation of step 2) is:

201) connecting the positive voltage end of the CT loop checking tool to a CT secondary winding tap S1 in a CT body terminal box;

202) the negative voltage terminal of the CT loop verification tool is connected to the CT secondary winding tap S2 in the CT body terminal box.

5. The method for checking the secondary circuit of the CT body as recited in claim 1, wherein the actual amplitude and direction of the forward voltage of the secondary circuit of the CT body and the actual amplitude and direction of the reverse voltage of the secondary circuit of the CT body are measured and recorded in the terminal box of the CT body through a direct-current voltage level of a multimeter according to a design drawing.

6. The CT body secondary loop verification method as claimed in claim 1, wherein the specific operation of step 6) is:

601) connecting the positive voltage end of the CT loop checking tool to a CT secondary winding tap S2 in a CT body terminal box;

602) the negative voltage terminal of the CT loop verification tool is connected to the CT secondary winding tap S1 in the CT body terminal box.

Technical Field

The invention belongs to the technical field of electrical installation and electrical debugging, and relates to a method for checking a secondary circuit of a CT body.

Background

With the continuous development of social economy, the living standard of people is increasingly improved, the power demand is increased day by day, various newly built units are continuously increased, and the scale of a power grid is continuously enlarged.

In the electrical installation and debugging process of a newly-built unit and a transformer substation, a CT (current transformer) loop is required to be ensured to be correct and reliable, no wiring error exists, and no open circuit phenomenon exists. The new unit and the transformer substation are high in voltage level, multiple in CT configuration and high in equipment reliability requirement, so that after the cable laying and installation wiring of the secondary circuit of the CT body are finished, the checking work of the secondary circuit of the CT body is needed, and the wiring of the secondary circuit of the CT body is ensured to be correct. When traditional CT body secondary circuit check-up, because CT secondary winding resistance is little, every group CT secondary winding body secondary circuit is the conducting state, consequently before CT body secondary circuit carries out the check-up work and begins, need demolish at least one core secondary cable on the binding post of taking a percentage of two secondary windings of CT body secondary circuit in CT body terminal box, just can carry out alone check-up to each CT body secondary circuit, check-up work is qualified after, resumes CT body secondary circuit wiring. The traditional CT body secondary circuit verification has the problems of long verification time, poor verification convenience, difficulty in disassembling the secondary winding terminal of the CT, high working strength and the like.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a CT body secondary circuit checking method which can accurately check whether the wiring of the CT body secondary circuit is correct and reliable, cables on two secondary side winding tap wiring terminals in the CT body secondary circuit in a CT body terminal box do not need to be dismantled during checking, the working strength is low, and the checking time is short.

In order to achieve the above object, the method for checking the secondary circuit of the CT body comprises the following steps:

1) carrying out CT body secondary circuit check preparation work;

2) carrying out positive pressurization verification work on a secondary circuit of the CT body by using a CT circuit verification tool;

3) measuring and recording the actual amplitude and direction of the forward voltage of the secondary circuit of the CT body;

4) judging whether the actual amplitude and direction of the forward voltage of the CT body secondary circuit are consistent with the amplitude and direction of the output voltage of the CT circuit checking tool or not, and turning to the step 6) when the actual amplitude and direction of the forward voltage of the CT body secondary circuit are consistent with the amplitude and direction of the output voltage of the CT circuit checking tool, or turning to the step 5) if not;

5) searching and eliminating the defects of the secondary circuit of the CT body, and then turning to the step 2);

6) carrying out reverse pressurization verification work on a secondary circuit of the CT body through a CT circuit verification tool;

7) measuring and recording the actual amplitude and direction of the reverse voltage of the secondary circuit of the CT body;

8) judging whether the actual amplitude and direction of the reverse voltage of the CT body secondary circuit are consistent with the amplitude and direction of the output voltage of the CT circuit checking tool or not, if so, turning to the step 10), otherwise, turning to the step 9);

9) searching and eliminating the defects of the secondary circuit of the CT body, and then turning to the step 6);

10) and finishing the checking of the secondary loop of the CT body.

The specific operation of the step 1) is as follows:

101) the CT body to be checked is in an uncharged state;

102) laying and arranging the cables of the secondary circuit from the CT body terminal box to be checked, and wiring the cables of the secondary circuit from the CT body terminal box to the CT body terminal box according to the design drawing;

103) opening the end cover of the terminal box of the CT body, and confirming that the parameters of each group of CT nameplates are consistent with the design parameters;

104) cutting off all current terminal connecting pieces in the CT body terminal box, and thoroughly isolating a CT body secondary loop from an external loop of the CT body terminal box in the CT body terminal box;

105) and manufacturing a CT loop checking tool.

The CT loop checking tool is formed by connecting dry battery packs in series.

The specific operation of the step 2) is as follows:

201) connecting the positive voltage end of the CT loop checking tool to a CT secondary winding tap S1 in a CT body terminal box;

202) the negative voltage terminal of the CT loop verification tool is connected to the CT secondary winding tap S2 in the CT body terminal box.

According to a design drawing, in a CT body terminal box, the actual amplitude and direction of the forward voltage of the secondary circuit of the CT body and the actual amplitude and direction of the reverse voltage of the secondary circuit of the CT body are measured and recorded through a direct-current voltage gear of a multimeter.

The specific operation of step 6) is:

601) connecting the positive voltage end of the CT loop checking tool to a CT secondary winding tap S2 in a CT body terminal box;

602) the negative voltage terminal of the CT loop verification tool is connected to the CT secondary winding tap S1 in the CT body terminal box.

The invention has the following beneficial effects:

the CT body secondary circuit checking method utilizes the CT circuit checking tool to carry out the forward pressurization checking work of the CT body secondary circuit and the reverse pressurization checking work of the CT body secondary circuit during specific operation, whether the actual amplitude and the direction of the voltage of the CT body secondary circuit are consistent with the amplitude and the direction of the output voltage of the CT circuit checking tool or not is judged, if the actual amplitude and the direction of the voltage of the CT body secondary circuit are inconsistent, the defect of the CT body secondary circuit exists, and if the actual amplitude and the direction of the voltage of the CT body secondary circuit are consistent during two times of checking, the wiring of the CT body secondary circuit is correct and reliable, so that the wiring of the CT body secondary circuit is correct and reliable, meanwhile, when the CT body secondary circuit is checked, cables on a wiring terminal of a CT secondary side winding tap in a CT body terminal box do not need to be detached, the working strength is lower, the, The electric debugging field is popularized and used, and effective guarantee is provided for the follow-up electrified operation of the CT loop.

Drawings

FIG. 1 is a flow chart of the present invention;

FIG. 2 is a connection diagram of a CT body and a CT circuit calibration tool;

fig. 3 is a schematic diagram of a CT main body terminal box.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings:

referring to fig. 1, 2 and 3, the CT body secondary circuit verification method of the present invention includes the following steps:

1) carrying out CT body secondary circuit check preparation work;

2) carrying out positive pressurization verification work on a secondary circuit of the CT body by using a CT circuit verification tool;

3) measuring and recording the actual amplitude and direction of the forward voltage of the secondary circuit of the CT body;

4) judging whether the actual amplitude and direction of the forward voltage of the CT body secondary circuit are consistent with the amplitude and direction of the output voltage of the CT circuit checking tool or not, and turning to the step 6) when the actual amplitude and direction of the forward voltage of the CT body secondary circuit are consistent with the amplitude and direction of the output voltage of the CT circuit checking tool, or turning to the step 5) if not;

5) searching and eliminating the defects of the secondary circuit of the CT body, and then turning to the step 2);

6) carrying out reverse pressurization verification work on a secondary circuit of the CT body through a CT circuit verification tool;

7) measuring and recording the actual amplitude and direction of the reverse voltage of the secondary circuit of the CT body;

8) judging whether the actual amplitude and direction of the reverse voltage of the CT body secondary circuit are consistent with the amplitude and direction of the output voltage of the CT circuit checking tool or not, if so, turning to the step 10), otherwise, turning to the step 9);

9) searching and eliminating the defects of the secondary circuit of the CT body, and then turning to the step 6);

10) and finishing the checking of the secondary loop of the CT body.

The specific operation of the step 1) is as follows:

101) the CT body to be checked is in an uncharged state;

102) laying and arranging the cables of the secondary circuit from the CT body terminal box to be checked, and wiring the cables of the secondary circuit from the CT body terminal box to the CT body terminal box according to the design drawing;

103) opening the end cover of the terminal box of the CT body, and confirming that the parameters of each group of CT nameplates are consistent with the design parameters;

104) cutting off all current terminal connecting pieces in the CT body terminal box, and thoroughly isolating a CT body secondary loop from an external loop of the CT body terminal box in the CT body terminal box;

105) and manufacturing a CT circuit checking tool, wherein the CT circuit checking tool is formed by connecting dry battery packs in series.

The specific operation of the step 2) is as follows:

201) connecting the positive voltage end of the CT loop checking tool to a CT secondary winding tap S1 in a CT body terminal box;

202) the negative voltage terminal of the CT loop verification tool is connected to the CT secondary winding tap S2 in the CT body terminal box.

According to a design drawing, in a CT body terminal box, the actual amplitude and direction of the forward voltage of the secondary circuit of the CT body and the actual amplitude and direction of the reverse voltage of the secondary circuit of the CT body are measured and recorded through a direct-current voltage gear of a multimeter.

The specific operation of step 6) is:

601) connecting the positive voltage end of the CT loop checking tool to a CT secondary winding tap S2 in a CT body terminal box;

602) the negative voltage terminal of the CT loop verification tool is connected to the CT secondary winding tap S1 in the CT body terminal box.

Judging whether the actual amplitude and direction of the forward voltage of the CT body secondary circuit are consistent with the amplitude and direction of the output voltage of the CT circuit checking tool or not, if not, searching and eliminating the defect of the 1L H C phase body secondary circuit, continuing to perform the forward pressurization checking work of the 1L HC phase body secondary circuit, after the forward pressurization checking is qualified, performing the reverse pressurization checking work of the 1L H C phase body secondary circuit, comparing the amplitude and direction of the CT circuit voltage measured in the generator CT body terminal box with the amplitude and direction of the voltage output in the 1L H C phase body terminal box through the CT circuit checking tool, if not, determining that the 1L H C phase body secondary circuit still has the defect, after the defect is eliminated, performing the reverse pressurization checking work of the 1L H C phase body secondary circuit again, and after the check is qualified, completing the checking of the CT body secondary circuit.

The method can save the checking time of the secondary circuit of the CT body, has high working efficiency, strong practicability and convenient use, can quickly and effectively identify the defects of the secondary circuit of the CT body, and is suitable for the checking field of the secondary circuits of various CT bodies.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, changes and equivalent structural changes made to the above embodiment according to the technical spirit of the present invention still fall within the protection scope of the technical solution of the present invention.