CN107064612A - Single-phase overhead transmission line of electricity phase voltage measuring method - Google Patents
Single-phase overhead transmission line of electricity phase voltage measuring method Download PDFInfo
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- G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
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Abstract
Circuit is considered as a bulky capacitor with the earth and carries out partial pressure measurement to it, dielectric is used as using air by a kind of measuring method of single-phase overhead transmission line of electricity phase voltage, utilization space principle of capacitive divider.According to the distribution capacity between wire distribution capacity over the ground and sensor and wire, lumped parameter equivalent circuit is set up, construct line voltage distribution measurement model, and analyze line levels change in actual applications does not influence on measurement.The phase voltage measuring method can obtain stable intrinsic standoff ratio, contactless transmission line of electricity phase voltage measurement be realized, it is adaptable to the requirement of distribution distributed devices, better than existing voltage measurement scheme.
Description
Technical field
The present invention relates to a kind of single-phase overhead transmission line of electricity phase voltage being applied in overhead line distributed electrical pressure sensor
Measuring method.
Background technology
With continuing to develop for China's power industry level, the developing direction that strong intelligent grid turns into following is built.
Current China's distribution network line has a large capacity and a wide range line length, and local environment is complicated, fault rate is high, developing low-cost distributed monitoring dress
Put, realize to the real time on-line monitoring with Running State with fault location to realizing that it is great that the operation of power distribution network high-efficiency and economic has
Meaning.
The accurate measurement of distribution to distribution network overhead line phase voltage is a difficult point.Now widely used voltage sensor
Device mainly has electromagnetic type (PT), condenser type (CVT) voltage transformer, optical voltage sensor etc..Optical voltage sensor is stable
Sex chromosome mosaicism is not yet solved very well, it is necessary to which high-precision processing technology and technique for sticking, not yet obtain extensive in electric power mutual-inductor
Using.Traditional PT capacity is smaller, cost is high, insulation system is complicated, there is ferromagnetic resonance phenomenon, have the factors such as leakage inductance distribution capacity
Influence, the demand of nowadays power network is not suitable with gradually.CVT is mainly used in more than 330kV power networks, and volume is big, involves great expense, no
It is easy to install, it is impossible to meet the requirement of inexpensive distributed devices.Therefore a kind of phase electricity suitable for distribution distributed devices is set up
Measuring method is pressed, an effective measurement model of unification is built and proves its validity and be particularly important.
The content of the invention
It is an object of the invention to propose a kind of new single-phase overhead power transmission line for being applied to miniaturization distributed devices
The measuring method of road phase voltage, overcomes the shortcomings of existing PT, CVT, optical voltage sensor, with high measurement accuracy.It will be defeated
Electric line is considered as voltage two-stage with the earth, and the plane-parallel capacitor for having upper bottom crown using one is placed in one as sampling capacitance,
Stray capacitance of two pieces of pole plates to voltage two-stage is taken into full account, lumped parameter equivalent circuit is set up, and with its in this analysis space
He produces influence of the factor to voltage measurement of stray capacitance, proposes the applicable measuring environment of this method.
The technical solution of the present invention is as follows：
A kind of single-phase overhead transmission line of electricity phase voltage measuring method, comprises the following steps：
1) distributed electrical pressure sensor is placed on overhead power transmission conducting wire.Utilization space principle of capacitive divider, by circuit with
The earth is considered as a bulky capacitor and carries out partial pressure measurement to it, using air as dielectric, according to the distribution capacity of wire over the ground
And the distribution capacity between sensor and wire, line voltage distribution measurement model is constructed, as shown in Figure 1.Measurement obtains sampling electricity
Magnitude of voltage is Δ U in appearance, and is inputted to background computer.
2) sampling capacitance C selected by need to be more than 4 orders of magnitude bigger than stray capacitance, generally nF~μ F ranks
3) voltage on its sampling capacitance and the intrinsic standoff ratio of circuit phase voltage can set up below equation：
WhereinCh1, Ch2For the electric capacity of two-plate to high-voltage conducting wires, Cg1、Cg2Arrived for two-plate
The electric capacity of the earth, C is the capacitance of the sampling capacitance between two-plate, and U is line voltage value to be measured.
4) line voltage distribution can be back-calculated to obtain by being calculated by Δ U and intrinsic standoff ratio.The intrinsic standoff ratio is pacified in actual distribution line
Fill in environment, line levels change does not influence on intrinsic standoff ratio.
Circuit is considered as one by the present invention as a result of above technical scheme, utilization space principle of capacitive divider with the earth
Individual bulky capacitor carries out partial pressure measurement to it, and dielectric is used as using air.According to wire distribution capacity over the ground and sensor with
Distribution capacity between wire, constructs line voltage distribution measurement model, and analyze line levels change pair in actual applications
Measurement does not influence, and the phase voltage measuring method can obtain stable intrinsic standoff ratio, realize contactless transmission line of electricity phase voltage
Measurement, better than existing scheme.
Brief description of the drawings
Fig. 1 is the two-plate phase voltage measurement model figure of the present invention.
Fig. 2 is the transmission line of electricity equivalent capacitance computation model figure of the present invention.
Fig. 3 is the voltage sensor work block diagram of present example
Fig. 4 is the voltage sensor circuit figure of present example
Fig. 5 is the sample waveform figure of present example
Embodiment
Embodiments of the invention are elaborated below in conjunction with accompanying drawing, but the protection model of the present invention should not be limited with this
Enclose.
Fig. 1, Fig. 2 are first referred to, Fig. 1 is the voltage measurement lumped parameter equivalent circuit of the present invention, and Fig. 2 is three-phase overhead line
Road equivalent capacitance computation model figure over the ground.As seen from the figure, single-phase overhead transmission line of electricity phase voltage measuring method of the present invention, including under
Row step：
1) distributed electrical pressure sensor is placed on overhead power transmission conducting wire.Utilization space principle of capacitive divider, by circuit with
The earth is considered as a bulky capacitor and carries out partial pressure measurement to it, using air as dielectric, according to the distribution capacity of wire over the ground
And the distribution capacity between sensor and wire, line voltage distribution measurement model is constructed, as shown in Figure 1.Measurement obtains sampling electricity
Magnitude of voltage is Δ U in appearance, and is inputted to background computer.
2) sampling capacitance C selected by need to be more than 4 orders of magnitude bigger than stray capacitance, generally nF~μ F ranks
3) voltage on its sampling capacitance and the intrinsic standoff ratio of circuit phase voltage can set up below equation：
WhereinCh1, Ch2For the electric capacity of two-plate to high-voltage conducting wires, Cg1、Cg2Arrived for two-plate
The electric capacity of the earth, C is the capacitance of the sampling capacitance between two-plate, and U is line voltage value to be measured.
4) line voltage distribution can be back-calculated to obtain by being calculated by Δ U and intrinsic standoff ratio.The intrinsic standoff ratio is pacified in actual distribution line
Fill in environment, line levels change does not influence on intrinsic standoff ratio.
The principle of the invention is as follows：
By distributed Voltage sensor surveying unit (hereinafter referred to as measurement apparatus) as on overhead transmission line, it is with empty
Between capacitance partial pressure principle measure traverse line phase voltage over the ground.Its core parts is a sampling capacitance, and wire is considered as into bulky capacitor
A pole, be greatly another pole.Sampling capacitance is inserted between wire and the earth, equivalent measurement circuit as shown in Figure 1 is formed.
Such as Fig. 1, node 1,2 is respectively the two poles of the earth for the derided capacitors placed, Ch1, Ch2For the electricity of two-plate to high-voltage conducting wires
Hold, Cg1、Cg2For the electric capacity of two-plate to the earth, C is the derided capacitors between two-plate.According to the pass of electric current in figure and voltage
System, can obtain following expression：
I1=(U-U1)jωCh1
I2=U1jωCg1
I3=(U1-U2)jωC
I4=(U-U2)jωCh2
I5=U2jωCg2
According to Kirchhoff's current law (KCL), it can obtain
I1=I2+I3
I5=I3+I4
Upper five formula is substituted into and abbreviation can be obtained：
(U1-U2) C=(U-U1)Ch1+U1Cg1
U2Cg2=(U1-U2)C+(U-U2)Ch2
Simplified and be melted into matrix form and be
Make Δ U=U1-U2, the ratio between voltage on derided capacitors and wire voltage can be tried to achieve：
OrderThen
Due to Ch1、Ch2、Cg1、Cg2For the stray capacitance of pole plate and space conductor, general all very little, the order of magnitude is several pF
To tens pF ranks, and that derided capacitors C capacitance can be chosen is very big, such as reaches μ F ranks, then C(Ch1+
Cg1)//(Cg2+Ch2)
Therefore, the accuracy of voltage measurement is dependent on CmWith C situation of change.C is sampling capacitance value, can be taking human as choosing
Take, its capacitance size is basically unchanged.CmFor spuious comprehensive electric capacity, pole plate direct-to-ground capacitance size is depended primarily on.
Three phase line equivalent capacitance model is as shown in Fig. 2 its calculation formula is as follows：
From three phase line equivalent capacitance calculation formula, in more than 1.7 meters of height, direct-to-ground capacitance rate of change is
Less than 0.5%；At highly more than 4 meters, direct-to-ground capacitance rate of change is less than 0.1%.General 10kV distribution lines highly are 12~
15 meters, rate of change of capacitance can be ignored.It is believed that distribution capacity is stable to actual distribution line over the ground.Therefore, may be used
To think, after measurement apparatus is fixed on distribution line, CmKeep stablizing constant with C, stable intrinsic standoff ratio can be obtained.
A kind of single-phase overhead transmission line of electricity phase voltage measuring method, its feature is as follows：
1) distributed electrical pressure sensor is placed on overhead power transmission conducting wire.Utilization space principle of capacitive divider, by circuit with
The earth is considered as a bulky capacitor and carries out partial pressure measurement to it, using air as dielectric, according to the distribution capacity of wire over the ground
And the distribution capacity between sensor and wire, line voltage distribution measurement model is constructed, as shown in Figure 1.Measurement obtains sampling electricity
Magnitude of voltage is Δ U in appearance.
2) line voltage distribution can be back-calculated to obtain by Δ U and intrinsic standoff ratio.Voltage and circuit phase voltage on its sampling capacitance
Intrinsic standoff ratio be
WhereinCh1, Ch2For the electric capacity of two-plate to high-voltage conducting wires, Cg1、Cg2Arrived for two-plate
The electric capacity of the earth, C is the capacitance of the sampling capacitance between two-plate, and U is line voltage value to be measured.
3) intrinsic standoff ratio is in actual distribution line installation environment, and height change does not influence on intrinsic standoff ratio
4) when about equal sign is set up, selected sampling capacitance C need to be more than 4 orders of magnitude bigger than stray capacitance, and its value is big
It is small to keep constant.
For checking effectiveness of the invention, devise an intelligent voltage for being applied to distribution line according to this invention and sense
Device, pcb board is directly welded in by derided capacitors C, and high-tension line is directly connected by conductor structure with C top crowns, C in Fig. 1h1、
Ch2、Cg1It can be neglected, be considered as C and pcb board direct-to-ground capacitance CgSeries connection.The upper voltage signals of C are passed through after conditioning amplification to be turned by sampling
Chemical conversion data signal, then transfer to communication module to carry out being wirelessly transmitted to system background by CPU progress processing, it is easy to preserve with after
Continuous analysis, its block diagram that worked after simplifying is as shown in Figure 3.Its follow-up modulate circuit of voltage sensor also includes amplification, filtering, protection
Etc. link, circuit diagram such as Fig. 4.Calculating device by Comsol Multiphysics, spuious distribution capacity is about over the ground
0.8pF, therefore design derided capacitors C=16nF, are tri- electric capacity parallel connections of C40, C41 and C42 in figure, bigger than stray capacitance by 4
The individual order of magnitude, for partial pressure post-sampling.R18, R22, C10, C14 are low pass filter, and the voltage signal collected is after filtering
After access to instrument amplifier ADS8237, it can turn round and look at elimination common mode interference signal and realize enlarging function.Its reference voltage is
1.5V, is easy to rear class ADC to gather signal using the ADS8237 direct current biasings that can add 1.5V, and the magnification ratio of signal passes through
Two resistance of R24 and R21 are set to be controlled.
Shaft tower is simulated using support, the parallel ground of wire is fixed, and connected with high pressure generator.Sensor is hung on
On wire, it is 10kv power frequency sinusoidal voltages that high pressure generator, which produces virtual value,.The poor Δ U of sensor collection electric capacity both end voltage, its
Internal work chip is MSP430F5438A, and sample rate is 1kHz, every time ten cycles of sampling.Sample waveform is as shown in figure 5, survey
Amount waveform is strict sinusoidal, it is seen that sensor can good collection voltages waveform.The sampled data for being back to backstage, which is calculated, to be had
Valid value, totally 14 groups, such as following table：
The stability test result of table 1
The peak excursion error for calculating this 14 groups of data is：
In summary, the collection voltages waveform that sensor can be good, and have what is stablized in the case where external condition is constant
Intrinsic standoff ratio.
Claims (1)
1. a kind of single-phase overhead transmission line of electricity phase voltage measuring method, it is characterised in that comprise the following steps：
1) distributed electrical pressure sensor is placed on overhead power transmission conducting wire, circuit is considered as a bulky capacitor with the earth, and utilize
Distributed electrical pressure sensor carries out partial pressure measurement, and it is Δ U to obtain magnitude of voltage on sampling capacitance C, and is inputted to background computer；
2) more than sampling capacitance C 4 orders of magnitude bigger than stray capacitance chosen, generally nF~μ F ranks；
3) according to the voltage on sampling capacitance and the intrinsic standoff ratio of circuit phase voltage, below equation is set up：
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WhereinCh1, Ch2For the electric capacity of two-plate to high-voltage conducting wires, Cg1、Cg2For two-plate to the earth
Electric capacity, C be two-plate between sampling capacitance capacitance, U be line voltage value to be measured；
4) calculated by magnitude of voltage Δ U and intrinsic standoff ratio and obtain line voltage value U to be measured.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110716081A (en) * | 2019-10-11 | 2020-01-21 | 国网福建省电力有限公司泉州供电公司 | Method for collecting field intensity type high-voltage line voltage harmonic signals |
| CN115825548A (en) * | 2022-12-12 | 2023-03-21 | 南方电网数字电网研究院有限公司 | Method and device for determining non-invasive voltage measurement model of high-voltage transmission line |
| CN115902372A (en) * | 2022-10-20 | 2023-04-04 | 广州商学院 | Direct-current voltage measuring method and device, electronic equipment and storage medium |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101893654A (en) * | 2010-06-25 | 2010-11-24 | 国网电力科学研究院 | Method and system for measuring transient overvoltage of high voltage power network through distribution capacitance method |
| CN102539888A (en) * | 2012-01-18 | 2012-07-04 | 周有庆 | Direct measurement capacitance-current primary voltage sensor |
| CN105116211A (en) * | 2015-08-27 | 2015-12-02 | 珠海许继电气有限公司 | Suspension type phase voltage measurement device |
| CN205003208U (en) * | 2015-08-27 | 2016-01-27 | 珠海许继电气有限公司 | Suspension type looks voltage measurement device |
| CN106124843A (en) * | 2016-07-08 | 2016-11-16 | 国网上海市电力公司 | A kind of wide frequency band measurement system of AC network transient process |
-
2017
- 2017-02-28 CN CN201710115062.0A patent/CN107064612B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101893654A (en) * | 2010-06-25 | 2010-11-24 | 国网电力科学研究院 | Method and system for measuring transient overvoltage of high voltage power network through distribution capacitance method |
| CN102539888A (en) * | 2012-01-18 | 2012-07-04 | 周有庆 | Direct measurement capacitance-current primary voltage sensor |
| CN105116211A (en) * | 2015-08-27 | 2015-12-02 | 珠海许继电气有限公司 | Suspension type phase voltage measurement device |
| CN205003208U (en) * | 2015-08-27 | 2016-01-27 | 珠海许继电气有限公司 | Suspension type looks voltage measurement device |
| CN106124843A (en) * | 2016-07-08 | 2016-11-16 | 国网上海市电力公司 | A kind of wide frequency band measurement system of AC network transient process |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110716081A (en) * | 2019-10-11 | 2020-01-21 | 国网福建省电力有限公司泉州供电公司 | Method for collecting field intensity type high-voltage line voltage harmonic signals |
| CN110716080A (en) * | 2019-10-11 | 2020-01-21 | 国网福建省电力有限公司泉州供电公司 | High-voltage transmission line three-phase voltage harmonic synchronous detection method |
| CN110716080B (en) * | 2019-10-11 | 2022-05-17 | 国网福建省电力有限公司泉州供电公司 | High-voltage transmission line three-phase voltage harmonic synchronous detection method |
| CN115902372A (en) * | 2022-10-20 | 2023-04-04 | 广州商学院 | Direct-current voltage measuring method and device, electronic equipment and storage medium |
| CN115902372B (en) * | 2022-10-20 | 2023-11-07 | 广州商学院 | Direct-current voltage measurement method and device, electronic equipment and storage medium |
| CN115825548A (en) * | 2022-12-12 | 2023-03-21 | 南方电网数字电网研究院有限公司 | Method and device for determining non-invasive voltage measurement model of high-voltage transmission line |
| CN115825548B (en) * | 2022-12-12 | 2023-09-15 | 南方电网数字电网研究院有限公司 | Method and device for determining non-invasive voltage measurement model of high-voltage transmission line |
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