CN113552433A - Method for measuring polarity of extra-high voltage transformer bushing - Google Patents
Method for measuring polarity of extra-high voltage transformer bushing Download PDFInfo
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- CN113552433A CN113552433A CN202110826967.5A CN202110826967A CN113552433A CN 113552433 A CN113552433 A CN 113552433A CN 202110826967 A CN202110826967 A CN 202110826967A CN 113552433 A CN113552433 A CN 113552433A
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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Abstract
A method for measuring the polarity of an extra-high voltage transformer bushing comprises the following steps: and (5) short-circuit transformer compensation variable secondary side EV, and measuring the variable polarity of the transformer main body. The method for measuring the polarity of the sleeve of the extra-high voltage transformer is characterized in that a secondary side of a transformer compensation transformer is in angle connection, and the method comprises the following steps: and short-circuiting two secondary sides of the transformer compensation transformer, and measuring the polarity of the transformer compensation transformer. By using the device, the magnetic flux type offset of the compensation variable secondary side can be eliminated, and the polarity of the transformer bushing can be measured.
Description
Technical Field
The invention relates to the field of transformer polarity determination, in particular to a method for determining the polarity of an extra-high voltage transformer bushing, which is particularly suitable for determining the polarity of the extra-high voltage transformer bushing.
Background
In the extra-high voltage project, the polarity orientation of a single casing needs to be confirmed before hoisting the casing, so that the polarity of the casing is arranged in an upward direction. In the prior art, a current transformer is generally used for confirming the polarity orientation of a single bushing, but the method can only determine the polarity of a single winding and cannot determine the polarity of each side of a main transformer and each functional bushing CT.
A method for measuring the polarity of a transformer bushing CT is briefly described in a journal document "method for measuring the polarity of a transformer bushing CT after installation" published in 2008 "protection and control of an electric power system" on 12.1.12.1. A journal document "study on a polarity test method after installation of a transformer bushing CT" of wireless interconnection technology "published in 2 months 2015 briefly describes another method for measuring the polarity of a transformer bushing CT. However, the polarity measurement after the installation of the transformer bushing CT can be used for transformers with voltage class of 500kV and below, and the method cannot be applied to 1000kV extra-high voltage main transformers, especially to voltage regulation compensation transformers of extra-high voltage main transformers. The reason is that the impedance of the extra-high voltage main transformer is large, if the polarity of the bushing CT is verified by a traditional direct-current battery point polarity method, the deflection of a pointer of a secondary series ammeter is small, and the polarity is not easy to observe and judge.
Disclosure of Invention
The invention aims to provide a method for measuring the polarity of an extra-high voltage transformer bushing, and provides a method for measuring the polarity of a transformer bushing from the perspective of a new technical route.
In the present invention, the short circuit means a short circuit connection.
In the present invention, the pointer meter is generally an ammeter, but may be a voltmeter.
The technical scheme of the invention is as follows:
a method for measuring the polarity of an extra-high voltage transformer bushing comprises the following steps: and (5) short-circuit transformer compensation variable secondary side EV, and measuring the variable polarity of the transformer main body.
Preferably, in the step of measuring the polarity of the transformer body, the method for measuring the polarity of the high-voltage side bushing of the transformer is as follows: the positive pole of a direct-current power supply is connected with a high-voltage side sleeve of a transformer, the negative pole of the direct-current power supply is connected with a neutral point sleeve of the transformer, when the polarity of the high-voltage side sleeve is correctly wired, the pointer meter flows into the primary polarity end of the high-voltage side sleeve to be positively deflected, and when the polarity of the neutral point sleeve is correctly wired, the pointer meter flows out of the primary polarity end of the neutral point sleeve to be reversely deflected.
Preferably, the method for measuring the polarity of the medium-voltage side bushing of the transformer comprises the following steps: the positive pole of a direct-current power supply is connected with a high-voltage side sleeve of a transformer, the negative pole of the direct-current power supply is connected with a medium-voltage side sleeve of the transformer, the secondary EV winding and the LT winding of the short-circuit transformer are adjusted and compensated, when the polarity wiring of the high-voltage side sleeve is correct, a pointer meter at the primary polarity end of the high-voltage side sleeve flows in the high-voltage side sleeve and is positively deflected, when the polarity wiring of the medium-voltage side sleeve is correct, a pointer meter at the primary polarity end of the medium-voltage side sleeve flows in the medium-voltage side sleeve and is negatively deflected, when the polarity wiring of the head end sleeve of the low-voltage side is correct, a pointer meter at the primary polarity end of the low-voltage side sleeve flows in the low-voltage side sleeve and is negatively deflected.
The method for measuring the polarity of the sleeve of the extra-high voltage transformer is characterized in that a secondary side of a transformer compensation transformer is in angle connection, and the method comprises the following steps: and short-circuiting two secondary sides of the transformer compensation transformer, and measuring the polarity of the transformer compensation transformer.
Preferably, the method for measuring the polarity of the regulating and compensating transformer of the transformer comprises the following steps: the positive pole of a direct-current power supply is connected with a neutral point changing sleeve or a compensation neutral point changing sleeve of a transformer main body, the negative pole of the direct-current power supply is connected with a neutral point, and when the polarity wiring of the compensation neutral point changing sleeve is correct, if the compensation neutral point changing sleeve is arranged at a positive gear, a pointer table at the primary polarity end of the compensation neutral point changing sleeve reversely deflects, and if the compensation neutral point changing sleeve is arranged at a negative gear, the pointer table at the primary polarity end of the compensation neutral point changing sleeve reversely deflects; when the polarity wiring of the low-voltage side head end sleeve is correct, the low-voltage side head end sleeve primary polarity end pointer meter reversely deflects; when the polarity wiring of the low-voltage side tail end sleeve is correct, the low-voltage side tail end sleeve reversely deflects the primary polarity end pointer meter.
The invention has the beneficial effects that:
1. the magnetic flux type offset at the side of the compensation variable secondary side can be eliminated, and the polarity of the extra-high voltage transformer bushing is measured.
Drawings
Fig. 1 is a schematic diagram of an extra-high voltage transformer.
FIG. 2 is an equivalent impedance diagram of a transformer and compensation transformer bushing CT winding of an extra-high voltage transformer main body.
Fig. 3 is a schematic diagram of the polarity of a CT point on the medium-voltage side of the main body of the extra-high voltage transformer.
FIG. 4 is a schematic diagram of polarity of a 1-4 gear point of the compensation transformer of the extra-high voltage transformer.
FIG. 5 is a schematic diagram of the polarity of the gear point of the compensation transformer 6-9 of the extra-high voltage transformer.
The reference numbers indicate that 1-transformer main body change, 2-transformer compensation change and 3-transformer voltage regulation change.
Detailed Description
The present invention is described below in terms of embodiments in conjunction with the accompanying drawings to assist those skilled in the art in understanding and implementing the present invention. Unless otherwise indicated, the following embodiments and technical terms therein should not be understood to depart from the background of the technical knowledge in the technical field.
The structure of the extra-high voltage transformer is divided into a main transformer part and a compensation transformer part, and the main transformer part and the compensation transformer part are used as a whole in the installation, inspection and operation stages to realize the functions of voltage transformation, voltage regulation and compensation. The main transformer realizes a transformation function, a primary coil is formed by SV-CV, electromotive force is induced by a secondary coil LV at a secondary side to complete a low-voltage 110kV transformation function, a 500kV tap is selected in a primary side SV winding wiring, and a medium-voltage 500kV transformation function is realized in a voltage-drawing mode; the regulating and compensating transformer realizes the voltage regulation and compensation functions of the main body after transformation. The voltage regulation is composed of a primary TV coil and a secondary EV coil, and the compensation is composed of a primary LE coil and a secondary LT coil. The main reason that the conventional point polarity does not deflect obviously is that the main body transformer and the compensation transformer share 3 secondary sides and are connected in a cross mode to jointly form an a-x end-to-end angular connection mode of a low-voltage 110kV system, namely a three-phase transformer, the connection mode has high impedance and an interference phenomenon, an interference source is offset from the flux mode of the secondary side of the compensation transformer, the offset is the main function that the normal phenomenon belongs to the compensation transformer, and the offset has adverse effects on the verification of the polarity of the sleeve of the ultra-high voltage transformer in the cross test stage.
The extra-high voltage main transformer non-excitation voltage regulation is divided into multiple gears according to needs, and polarity and compensation variable parameter fixed values under different gears are generally respectively solidified to corresponding fixed value areas. Therefore, the gears of the extra-high voltage compensation transformer are divided into a positive gear and a negative gear, and the positive gear and the negative gear can form opposite polarities due to a primary wiring mode of the gears (namely, the positive gear and the negative gear have different positive and negative bias effects). The compensation transformer protection device matches the actual primary polarity by inverting the polarity through software logic. Generally, an extra-high voltage main transformer has no excitation voltage regulation and has a middle gear rated gear, the wiring mode of the extra-high voltage main transformer is direct grounding, and the extra-high voltage main transformer is equivalent to that the primary side of a voltage regulation winding is in short circuit without a voltage regulation coil.
Fig. 1 shows a schematic diagram of a transformer. In the figure, a terminal a is a high-voltage side, a terminal Am is a medium-voltage side, a terminal X is a neutral point (i.e., a neutral grounding point), a terminal a is a head end of a low-voltage side angle connection, and a terminal X is a tail end of a low-voltage side angle connection (the low-voltage sides of the three-phase extra-high voltage transformer are connected end to end).
Example 1: a method for measuring the polarity of a high-voltage side sleeve of an extra-high voltage transformer is disclosed, and referring to fig. 2, the method comprises the following steps:
and the short-circuit transformer compensates the secondary side EV, so that the interference of the magnetomotive force of the voltage-regulating variable winding on the point polarity can be eliminated, a single closed loop is formed on the secondary side of the main body transformer, and the polarity change verification of the main body is realized.
The positive pole of a direct-current power supply is connected with an extra-high voltage transformer A sleeve, the negative pole of the direct-current power supply is connected with an extra-high voltage transformer neutral point X sleeve, when the polarity wiring of the high-voltage side sleeve is correct, the pointer meter flowing into the high-voltage side sleeve and at the primary polarity end is deflected positively, and when the polarity wiring of the neutral point sleeve is correct, the pointer meter flowing out of the neutral point sleeve and at the primary polarity end is deflected reversely. The direct current power supply can adopt a 3V power supply. And the short-circuit transformer compensates the secondary side EV, so that the interference of the magnetomotive force of the voltage-regulating variable winding on the point polarity can be eliminated, a single closed loop is formed on the secondary side of the main body transformer, and the polarity change verification of the main body is realized.
It should be understood that when the gear of the transformer compensation transformer is set to the middle gear rated gear, the gear is equivalent to the secondary side EV of the short-circuit transformer compensation transformer.
Example 2: a method for measuring the polarity of a sleeve on the medium-voltage side of an extra-high voltage transformer is disclosed, and referring to fig. 3, the method comprises the following steps:
and the short-circuit transformer compensates the secondary side EV, so that the interference of the magnetomotive force of the voltage-regulating variable winding on the point polarity can be eliminated, a single closed loop is formed on the secondary side of the main body transformer, and the polarity change verification of the main body is realized.
The positive pole of a direct-current power supply is connected with an A sleeve of the extra-high voltage transformer, the negative pole of the direct-current power supply is connected with an Am sleeve at the medium-voltage side of the extra-high voltage transformer, and x1 and a1 are in short circuit (namely, the EV winding and the LT winding are in short circuit), at the moment, the direct-current power supply forms magnetomotive force of the LV winding, and the purpose of reducing the disturbance of the modulation and compensation magnetomotive force is achieved. When the polarity wiring of the high-voltage side sleeve is correct, the high-voltage side sleeve flows into the primary polarity end pointer meter of the high-voltage side sleeve to be positively deflected, when the polarity wiring of the medium-voltage side sleeve is correct, the medium-voltage side sleeve flows into the primary polarity end pointer meter of the medium-voltage side sleeve to be negatively deflected, when the polarity wiring of the low-voltage side head end sleeve is correct, the low-voltage side head end sleeve flows into the primary polarity end pointer meter of the low-voltage side sleeve to be positively deflected, and when the polarity wiring of the low-voltage side tail end sleeve is correct, the low-voltage side tail end sleeve flows out of the primary polarity end pointer meter of the low-voltage side sleeve to be negatively deflected. During verification and measurement, the primary polarity end pointer meter of the high-voltage side sleeve and the low-voltage side head end sleeve deflects positively, and the primary polarity end pointer meter of the medium-voltage side sleeve and the low-voltage side tail end sleeve deflects reversely.
It should be understood that when the gear of the transformer compensation transformer is set to the middle gear rated gear, it is equivalent to short-circuit the EV winding and the LT winding of the transformer compensation transformer.
Example 3: a method for measuring the polarity of an extra-high voltage transformer compensation transformer is characterized in that a secondary side of the transformer compensation transformer is in angle connection, and the method comprises the following steps:
when the polarity wiring of the adjusting and compensating neutral point sleeve is correct, if the gear of the extra-high voltage adjusting and compensating neutral point sleeve is set at a positive gear (see figure 4), the pointer table of the primary polarity end of the extra-high voltage adjusting and compensating neutral point sleeve reversely deflects, and if the gear of the extra-high voltage adjusting and compensating neutral point sleeve is set at a negative gear (see figure 5), the pointer table of the primary polarity end of the extra-high voltage adjusting and compensating neutral point sleeve reversely deflects; when the polarity wiring of the low-voltage side head end sleeve is correct, no matter whether the gear of the extra-high voltage compensation transformer is set at a positive gear or a negative gear, the low-voltage side head end sleeve primary polarity end pointer table reversely deflects; when the polarity wiring of the low-voltage side tail end sleeve is correct, no matter whether the gear of the extra-high voltage compensation transformer is set at a positive gear or a negative gear, the low-voltage side tail end sleeve reversely deflects the primary polarity end pointer meter.
The invention is described in detail above with reference to the figures and examples. It should be understood that in practice the description of all possible embodiments is not exhaustive and that the inventive concepts are described herein as far as possible by way of illustration. Without departing from the inventive concept of the present invention and without any creative work, a person skilled in the art should, in all of the embodiments, make optional combinations of technical features and experimental changes of specific parameters, or make a routine replacement of the disclosed technical means by using the prior art in the technical field to form specific embodiments, which belong to the content implicitly disclosed by the present invention.
Claims (5)
1. The method for measuring the polarity of the casing of the extra-high voltage transformer is characterized by comprising the following steps of: and (5) short-circuit transformer compensation variable secondary side EV, and measuring the variable polarity of the transformer main body.
2. The method for determining the polarity of the extra-high voltage transformer bushing according to claim 1, wherein in the step of measuring the polarity of the transformer body, the method for measuring the polarity of the bushing on the high voltage side of the transformer comprises the following steps: the positive pole of a direct-current power supply is connected with a high-voltage side sleeve of a transformer, the negative pole of the direct-current power supply is connected with a neutral point sleeve of the transformer, when the polarity of the high-voltage side sleeve is correctly wired, the pointer meter flows into the primary polarity end of the high-voltage side sleeve to be positively deflected, and when the polarity of the neutral point sleeve is correctly wired, the pointer meter flows out of the primary polarity end of the neutral point sleeve to be reversely deflected.
3. The method for determining the polarity of the casing of the extra-high voltage transformer as claimed in claim 1, wherein the method for measuring the polarity of the casing on the medium-voltage side of the transformer comprises the following steps: the positive pole of a direct-current power supply is connected with a high-voltage side sleeve of a transformer, the negative pole of the direct-current power supply is connected with a medium-voltage side sleeve of the transformer, the secondary EV winding and the LT winding of the short-circuit transformer are adjusted and compensated, when the polarity wiring of the high-voltage side sleeve is correct, a pointer meter at the primary polarity end of the high-voltage side sleeve flows in the high-voltage side sleeve and is positively deflected, when the polarity wiring of the medium-voltage side sleeve is correct, a pointer meter at the primary polarity end of the medium-voltage side sleeve flows in the medium-voltage side sleeve and is negatively deflected, when the polarity wiring of the head end sleeve of the low-voltage side is correct, a pointer meter at the primary polarity end of the low-voltage side sleeve flows in the low-voltage side sleeve and is negatively deflected.
4. The method for measuring the polarity of the sleeve of the extra-high voltage transformer is characterized in that a secondary side of a transformer compensation transformer is in angle connection, and the method comprises the following steps: and short-circuiting two secondary sides of the transformer compensation transformer, and measuring the polarity of the transformer compensation transformer.
5. The method for determining the polarity of the extra-high voltage transformer bushing according to claim 4, wherein the method for measuring the polarity of the transformer compensation transformer comprises the following steps: the positive pole of a direct-current power supply is connected with a neutral point changing sleeve or a compensation neutral point changing sleeve of a transformer main body, the negative pole of the direct-current power supply is connected with a neutral point, and when the polarity wiring of the compensation neutral point changing sleeve is correct, if the compensation neutral point changing sleeve is arranged at a positive gear, a pointer table at the primary polarity end of the compensation neutral point changing sleeve reversely deflects, and if the compensation neutral point changing sleeve is arranged at a negative gear, the pointer table at the primary polarity end of the compensation neutral point changing sleeve reversely deflects; when the polarity wiring of the low-voltage side head end sleeve is correct, the low-voltage side head end sleeve primary polarity end pointer meter reversely deflects; when the polarity wiring of the low-voltage side tail end sleeve is correct, the low-voltage side tail end sleeve reversely deflects the primary polarity end pointer meter.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202110826967.5A CN113552433B (en) | 2021-07-21 | 2021-07-21 | Method for measuring CT polarity of extra-high voltage transformer bushing |
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| CN202110826967.5A CN113552433B (en) | 2021-07-21 | 2021-07-21 | Method for measuring CT polarity of extra-high voltage transformer bushing |
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| CN113552433B CN113552433B (en) | 2022-08-09 |
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2021
- 2021-07-21 CN CN202110826967.5A patent/CN113552433B/en active Active
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| CN103424583A (en) * | 2013-08-13 | 2013-12-04 | 中国电力科学研究院 | Automatic polarity-changing direct current boosting device |
| CN203519764U (en) * | 2013-10-10 | 2014-04-02 | 国家电网公司 | Current transformer polarity checking device with power transmission and transformation rising current at primary winding |
| RU2687298C1 (en) * | 2018-04-20 | 2019-05-13 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Кубанский государственный аграрный университет имени И.Т. Трубилина" | Method for measuring active resistances to direct current windings of a power transformer |
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