CN109725193A - It is a kind of for running the suspension type neutral point undervoltage detection means for doing anti-defect diagonsis - Google Patents
It is a kind of for running the suspension type neutral point undervoltage detection means for doing anti-defect diagonsis Download PDFInfo
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- CN109725193A CN109725193A CN201910136291.XA CN201910136291A CN109725193A CN 109725193 A CN109725193 A CN 109725193A CN 201910136291 A CN201910136291 A CN 201910136291A CN 109725193 A CN109725193 A CN 109725193A
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- 239000000725 suspension Substances 0.000 title claims abstract description 15
- 230000007935 neutral effect Effects 0.000 title claims abstract description 14
- 238000001514 detection method Methods 0.000 title claims abstract description 13
- 239000003990 capacitor Substances 0.000 claims abstract description 45
- 238000000034 method Methods 0.000 claims description 5
- 239000007769 metal material Substances 0.000 claims description 4
- 239000011810 insulating material Substances 0.000 claims description 3
- 238000009413 insulation Methods 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 238000005555 metalworking Methods 0.000 claims description 2
- 238000004804 winding Methods 0.000 claims description 2
- 238000005259 measurement Methods 0.000 abstract description 14
- 238000010276 construction Methods 0.000 abstract description 9
- 230000005684 electric field Effects 0.000 abstract description 9
- 238000009434 installation Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 4
- 238000009826 distribution Methods 0.000 description 3
- 230000005611 electricity Effects 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 1
- 238000005094 computer simulation Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000011282 treatment Methods 0.000 description 1
- 230000017260 vegetative to reproductive phase transition of meristem Effects 0.000 description 1
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Abstract
The invention discloses a kind of for running the suspension type neutral point undervoltage detection means for doing anti-defect diagonsis, belongs to voltage sensor field.This suspension type neutral point undervoltage detection means are made of inside partial pressure shielding construction, insulating cylinder and grading ring, and whole shielding construction is included in high voltage arm capacitor C1It is provided with high-pressure side housing outside, in low-voltage arm capacitor C2Low-pressure side housing is externally provided with low-voltage capacitance lead.The present invention proposes a kind of capacitive divider of novel shielding structure for stray capacitive currents, by reducing the stray capacitance between capacitance electrode and nearby device, interference of the external electrical field between electric field capacitance electrode is reduced by housing, to realize the purpose for improving measurement accuracy and measuring stability.The suspension type neutral point undervoltage detection means of offer have the characteristics that small volume weight, simple installation, measurement accuracy height, strong antijamming capability, high reliablity.
Description
Technical field
The present invention relates to voltage sensor technical fields, in particular to a kind of that high-precision is obtained using novel shielding structure
With the suspension type neutral point undervoltage detection means of high anti-interference ability.
Background technique
Standard capacitor divider is generally connected in series by high-voltage arm main capacitance and low-voltage arm main capacitance, due to the master of high-voltage arm
Capacitance is larger, can also use in high-voltage arm by several concatenated structures of low capacity capacitor, can also use in low-voltage arm will
The structure of several capacitor parallel connections.When adding voltage at ideal capacitor both ends, displacement current is only existed in capacitor.But
When actual capacitor both ends add voltage, some leakage current how much is understood in the insulating materials of capacitor and is flowed through, this portion
The intrinsic standoff ratio for dividing leakage current that can change standard capacitor divider makes measurement error occur.High-precision standard electric in order to obtain
Hold divider, needs to reduce as far as possible the leakage current of standard capacitor divider.Anti- neutral point voltage detection is done in operation
In, since position is higher from the ground for neutral point, if divider is installed on ground, would have to draw using long range high pressure
Line, the antenna effect under strong electromagnetic interference environment, will lead to the introducing of various interference signals, cannot achieve precise measurement.
Summary of the invention
To solve the above-mentioned problems, the invention proposes one kind have volume weight is small, simple installation, measurement accuracy are high,
The suspension type neutral point undervoltage detection means of the characteristics of strong antijamming capability, high reliablity.
It is provided by the invention a kind of for running the suspension type neutral point undervoltage detection means for doing anti-defect diagonsis by height
Press side shield cover, grading ring, external shield cylinder and derided capacitors C1 and C2 composition；
External shield cylinder, using whole winding process manufacture, is integrally formed by insulating materials, and SF6 gas conduct is filled in inside, hangs
The shell of hanging neutral point undervoltage detection means；
Grading ring is fixed on external shield cylinder by fastening latching；
High-pressure side shielding case is metal material, is formed by metal working process, cylindrical shape, upper end cover is fixed on external screen
It covers at the top of cylinder, realizes and be electrically connected with grading ring, it is whole to surround high pressure derided capacitors C1；
External shield cylinder uses metal material back cover by bottom, is integrally formed, internal to be electrically connected with low pressure derided capacitors C2,
Outside is connected by binding post and is grounded；
Preferably, high-pressure side shielding case integrally surrounds high pressure derided capacitors C1, and to reach external shield cylinder integrally exhausted for length
The 46% of edge length；
Preferably, suspension hook can be arranged in the central point of grading ring according to field device situation；Suspension hook passes through interior
Embedding bolt hole is mechanically and electrically with grading ring realization.
Preferably, high pressure derided capacitors C1, can be composed in series according to intrinsic standoff ratio by more large capacity high-voltage capacitances.
Preferably, low pressure derided capacitors C2, can be composed in parallel according to intrinsic standoff ratio by more large capacity high-voltage capacitances.
Detailed description of the invention
Fig. 1 is shielding construction schematic diagram provided in an embodiment of the present invention.
Fig. 2 is structure principle chart provided in an embodiment of the present invention.
Fig. 3 is actual conditions flowering structure circuit diagram provided in an embodiment of the present invention.
Fig. 4 is shielding construction schematic diagram provided in an embodiment of the present invention.
Fig. 5 is the simulation model of shielding construction provided in an embodiment of the present invention.
Fig. 6 be it is provided in an embodiment of the present invention have shielding it is noiseless when voltage distribution graph.
Fig. 7 be it is provided in an embodiment of the present invention have shielding it is noiseless when distribution map of the electric field.
Fig. 8 is the temperature characteristic compensation provided in an embodiment of the present invention using temperature sensor.
Fig. 9 is the relational graph of temperature error provided in an embodiment of the present invention and temperature.
Specific embodiment
In order to understand the present invention in depth, the present invention is described in detail combined with specific embodiments below.
Provided by the present invention for running the suspension type neutral point undervoltage detection means for doing anti-defect diagonsis by inner part
Shielding construction, insulating cylinder and grading ring composition, whole shielding construction is pressed to be included in high voltage arm capacitor C1It is provided with high-pressure side outside
Housing, in low-voltage arm capacitor C2Low-pressure side housing is externally provided with low-voltage capacitance lead.
The main composition portion of capacitance type potential transformer includes two-stage standard capacitor divider, A/D conversion module, at data
It manages module and data shows that output module, structural principle are as shown in Figure 2.
Capacitive battery minor voltage transformer is by two-stage standard capacitor divider first by bus when measuring voltage
On high voltage be reduced to the medium voltage at low-voltage arm capacitor both ends, then medium voltage is simulated by A/D conversion module
Signal is converted to digital signal, handles in the data processing module of secondary side signal data, obtains the electricity of primary side
Signal is pressed, and calculates its amplitude and phase, shows that output module is exported finally by data.
In the basic structure of CVT, the precision and stability of standard capacitor divider has the measurement accuracy of CVT very heavy
The influence wanted, the contents of the present invention are mainly focused on the shielding measure of standard capacitor divider.
Only have displacement current to flow through in the capacitor of standard capacitor divider ideally, the voltage of low-voltage arm and high-voltage arm
Relationship is as shown by the equation.But in actual operation, since there are leakage currents in standard capacitance, leakage current is equivalent to
One resistance in parallel with standard capacitance, then the standard capacitor divider structure of actual motion is as shown in Figure 3.
The intrinsic standoff ratio and frequency of the standard capacitor divider of ideal situation are unrelated, but the standard voltage divider in actual motion
Intrinsic standoff ratio be it is related with frequency, as shown by the equation:
It can be seen that due to the presence of leakage current equivalent resistance, the intrinsic standoff ratio precision of actual standard capacitor divider
It will receive influence, reduce leakage current, so that it may improve the precision of standard capacitor divider.
Leakage current in standard capacitor divider is mainly made of two parts, and a part is in capacitor internal and outside
Insulation stent on have fraction electric current flowing, this part can be referred to as insulated leakage current, and another part is due to electricity
The electric current for the very little that the electrode and nearby device of container are generated by stray capacitance hinge, this part can be known as stray electrical
Capacitance current, this two parts electric current can become the leakage current of standard capacitor divider altogether.In high-precision measurement, need
Consider that leakage current influences measurement accuracy bring.
The present invention proposes a kind of capacitive divider of novel shielding structure for stray capacitive currents, by reducing capacitor electricity
Stray capacitance between pole and nearby device improves measurement accuracy and measurement stability.
Whole shielding construction is included in high voltage arm capacitor C1It is provided with high-pressure side housing outside, in low-voltage arm capacitor C2With
Low-voltage capacitance lead is externally provided with low-pressure side housing, reduces interference of the external electrical field between electric field capacitance electrode by housing,
To realize the purpose for improving measurement stability.The schematic diagram of shielding construction is as shown in Figure 1.
Emulation is carried out using ANSOFT software, and the capacitive divider model established in emulation is as shown in the figure.High pressure lateral capacitance
Using concentric cylinder capacitor, and some smooth treatments have been done to reduce electric field strength, fill SF6 gas between the capacitance electrode of high-pressure side
Gap.Low pressure lateral capacitance uses plane-parallel capacitor, and filled media is film paper complex media, dielectric constant 3.5.High-pressure side housing
It extends downwardly, low-pressure side housing upwardly extends, and the two covers entire capacitive divider in height together.
By computer sim- ulation, obtaining capacitive divider is having housing, voltage's distribiuting such as Fig. 6 in the case of no external interference
Shown, distribution map of the electric field is as shown in Figure 7.The maximum value of electric field appears in the electrode of plane-parallel capacitor as can see from Figure 6
Between, the electric field intensity value of rest part is relatively low, can satisfy the requirement of insulation.
Respectively to have shielding it is noiseless, have shielding have interference, it is unshielded it is noiseless, unshielded have interference four kinds in the case of
Capacitive divider is emulated, and it is as shown in the table for obtained intermediate voltage value.
1 medium voltage simulation result of table
In order to further decrease the influence of temperature, the stability of intrinsic standoff ratio is improved, this section proposes a kind of using temperature sensing
The capacitive divider temperature characteristic compensation of device.Its structure is put as shown in figure 8, compared with Fig. 1 in the different parts of capacitive divider
6 temperature sensors are set.
2 capacitive divider temperature characteristic data of table
| Temperature (DEG C) | Test voltage (KV) | Medium voltage (V) | Temperature error (%) |
| 0.1 | 50.641 | 11.6263 | 0.034 |
| 15.3 | 50.527 | 11.6002 | 0.035 |
| 30.1 | 50.769 | 11.6549 | 0.027 |
| 45.2 | 50.749 | 11.6504 | 0.028 |
| 59.6 | 50.970 | 11.7034 | 0.048 |
Capacitive divider model machine is put into temperature-controlled chamber, 0~60.It is adjusted within the scope of DEG C, in 5 different temperature
Point applies voltage rating, measures the temperature characterisitic of capacitive divider, it is as shown in the table for test result.By the pass of temperature error and temperature
System's mapping is as shown in Figure 9.When using capacitive divider, the temperature obtained according to actual measurement uses interpolation calculation in Fig. 9
Temperature error is obtained, is then modified according to the intermediate voltage value that temperature error obtains measurement.
It can see from the data in table 1, after using shielding measure as shown in Figure 4, extraneous interference is to centre
Voltage value does not influence, and the difference for having medium voltage when interfering and is noiseless is 0.00%.And when not using shielding measure,
Have interference and it is noiseless when, median voltage difference value 10.79%,
The result of calculating illustrates that novel shielding structure can effectively reduce external interference to capacitive divider medium voltage
The influence of value improves the precision and stability of measurement.
Claims (5)
1. a kind of for running the suspension type neutral point undervoltage detection means for doing anti-defect diagonsis, which is characterized in that including height
Press side shield cover (2), grading ring (3), external shield cylinder (1) and derided capacitors C1 and C2；
The external shield cylinder (1), using whole winding process manufacture, is integrally formed by insulating materials, and SF6 gas conduct is filled in inside,
The shell of suspension type neutral point undervoltage detection means；
The grading ring (3) is fixed on external shield cylinder (1) by fastening latching；
The high-pressure side shielding case (2) is metal material, is formed by metal working process, cylindrical shape, upper end cover is fixed on
At the top of external shield cylinder (1), realizes and be electrically connected with grading ring (3), it is whole to surround high pressure derided capacitors C1；
The external shield cylinder (1) uses metal material back cover by bottom, is integrally formed, and inside electrically connects with low pressure derided capacitors C2
It connects, external connected by binding post is grounded.
2. high-pressure side shielding case according to claim 1, which is characterized in that the high-pressure side shielding case (2) is integrally surrounded
High pressure derided capacitors C1, and length reaches the 46% of external shield cylinder (1) integral insulation length.
3. grading ring according to claim 1, which is characterized in that the central point of the grading ring (3) can be set according to scene
Standby situation setting suspension hook；Suspension hook is realized with the grading ring (3) by embedded bolt hole and is mechanically and electrically.
4. high pressure derided capacitors C1 according to claim 1, which is characterized in that can be according to intrinsic standoff ratio, by more large capacities
High-voltage capacitance is composed in series.
5. low pressure derided capacitors C2 according to claim 1, which is characterized in that can be according to intrinsic standoff ratio, by more large capacities
High-voltage capacitance composes in parallel.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201910136291.XA CN109725193A (en) | 2019-02-25 | 2019-02-25 | It is a kind of for running the suspension type neutral point undervoltage detection means for doing anti-defect diagonsis |
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| CN201910136291.XA CN109725193A (en) | 2019-02-25 | 2019-02-25 | It is a kind of for running the suspension type neutral point undervoltage detection means for doing anti-defect diagonsis |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4142133A1 (en) * | 2021-08-30 | 2023-03-01 | Murata Manufacturing Co., Ltd. | An electrical device comprising an ac voltage divider and capacitors arranged in integrated components |
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