CN109061276A - A kind of isolated neutral system capacitance current test device and its test method - Google Patents
A kind of isolated neutral system capacitance current test device and its test method Download PDFInfo
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- CN109061276A CN109061276A CN201811008153.5A CN201811008153A CN109061276A CN 109061276 A CN109061276 A CN 109061276A CN 201811008153 A CN201811008153 A CN 201811008153A CN 109061276 A CN109061276 A CN 109061276A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
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Abstract
The invention discloses a kind of isolated neutral system capacitance current test device and its test methods, including neutral point Capacitive current tester and jointing clamp, jointing clamp is connected to neutral point Capacitive current tester by p-wire, the ground terminal of neutral point Capacitive current tester connects ground, and handheld terminal is connected to by wireless module, jointing clamp is mounted in operating stick.The present invention realizes the electric current and capacitor automatic measurement of long-range neutral point, the arrangement achieves only tester being needed to connect p-wire, tester can complete measurement process in safety zone remote host, it is no longer necessary to which other testers cooperate wiring, reading, the manual operations such as record；The personnel safety of test is significantly improved, it is significant to shorten the testing time, operator's quantity is reduced, test operation is safe and accurate, quick, and the present invention also has the characteristics that structure is simple, at low cost.
Description
Technical field
The present invention relates to a kind of isolated neutral system capacitance current test device and its test methods, belong to earth-free
System capacitive current the field of test technology.
Background technique
What the mains neutral point of China's distribution system was not directly grounded usually, so flowing through event when route single-phase earthing
The electric current of barrier point is really the capacitance current that line mutual-ground capacitor generates.According to statistics, the failure of power distribution network is largely due to
Capacitance current is excessive and can not voluntarily cease caused by arc when route single-phase earthing.Therefore, the electric power regulation regulation in China is worked as
When 10kV and 35kV system capacitive current is respectively greater than 30A and 10A, arc suppression coil should be installed with compensating electric capacity electric current, this will
It asks and the capacitance current of power distribution network is measured.In addition, to generate PT ferromagnetic for the direct-to-ground capacitance of power distribution network and the parameter coordination of PT
Resonance overvoltage.Whether PT resonance can occur in order to verify the distribution network systems and the resonance of what property occurs, it is also necessary to is accurate
Measure the capacitive earth current of power distribution network.The safety problem that we cope with power grid in view of the foregoing causes enough attention, in order to
The generation for reducing safety accident, protects the normal operation of power supply system, and the detection and improvement to distribution network capacitance current test are exactly very
Important.
In today of rapid economic development, it is more and more important how to ensure that power supply system does not occur to interrupt.According to statistics, distribution
Most of line fault is singlephase earth fault, and when capacitance current is little in system, ground arc can be with self-extinguish；But work as
When capacitance current is excessive, when route single-phase earthing capacitance current it is excessive and can not voluntarily blow-out, arc reignition can generate very high
System overvoltage jeopardizes the insulation for perfecting phase and causes the accidents such as line to line fault, in addition, the ginseng of the direct-to-ground capacitance of power distribution network and PT
Number generates PT ferro-resonance over-voltage with credit union.Make fault spread, has when distribution accident due to caused by singlephase earth fault
Occur.For example, certain southern substation causes dielectric breakdown accident because of single-phase earthing twice in succession, line to line fault, big face are caused
Product had a power failure for more than ten a hours.Therefore, China electric power regulation regulation when 10kV and 35kV system capacitive current be respectively greater than 30A and
When 10A, arc suppression coil should be installed with compensating electric capacity electric current, this requires the capacitance currents to power distribution network to measure.It is accurate to survey
The capacitance current of amount distribution is the premise of ideal compensation, is had important practical significance.
Conventional test methodologies are realized under technical conditions at that time, by various test instrumentations, test capacitors group
With various jointers, cooperated by several testers, in strict accordance with defined testing procedure under the commander of commanding
It is gradually completing entire test process, takes time to grow, tester's spirit high concentration can just smoothly complete test process.
Summary of the invention
The technical problem to be solved by the present invention is provide a kind of isolated neutral system capacitance current test device and its
Test method, to solve problems of the prior art.
The technical scheme adopted by the invention is as follows: a kind of isolated neutral system capacitance current test device, including neutrality
Point Capacitive current tester and overhead jointing clamp, overhead jointing clamp are connected to neutral point Capacitive current tester by p-wire,
The ground terminal of neutral point Capacitive current tester connects ground, and is connected to handheld terminal, overhead jointing clamp peace by wireless module
In operating stick.
Preferably, high-tension fuse is connected between above-mentioned p-wire and overhead jointing clamp, high-tension fuse is fixedly connected on
In operating stick.
A kind of test method of isolated neutral system capacitance current test device, comprising the following steps:
(1) tester places neutral point Capacitive current tester and powers on, and p-wire one end connects host connecting terminal,
The other end is articulated to the neutral point exit of system under test (SUT) using hand-held insulating bar operation overhead jointing clamp；
(2) tester starts measurement process by handheld terminal remote control neutral point Capacitive current tester；
(3) neutral point Capacitive current tester is automatically performed measurement process, measures asymmetrical voltage UHCWith displacement voltage U0
And it calculates capacitance current measurement result automatically and is uploaded to handheld terminal；
(4) tester's handheld terminal checks test data and saves result.
Formula of capacitive current is as follows in step (3):
IC=ω ∑ CxUφ
In formula, ∑ CxFor measured capacitance, ∑ Cx=CA+CB+CC, μ F, CA、CB、CCRespectively system under test (SUT) is three relatively electric
Hold；
C0For additional capacitor, μ F；
U0For displacement voltage, i.e., end voltage on capacitor, V；
UHCFor three relatively asymmetrical voltages, V；
ICFor the capacitance current of tested network, A；
ω is angular frequency；
UφFor power grid specified phase voltage, V.
Beneficial effects of the present invention: compared with prior art, the present invention is tested neutral point using high-altitude wiring clipper joint
On pile crown, the neutral point Capacitive current tester of distal end is connected to by p-wire, neutral point Capacitive current tester passes through nothing
The handheld terminal that wire module (GPRS module, WIFI module etc.) transfers data to distal end, realizes the electric current of long-range neutral point
With capacitor automatic measurement, the arrangement achieves only tester being needed to connect p-wire, tester can be in safety zone
Domain remote host completes measurement process, it is no longer necessary to which other testers cooperate wiring, reading, the manual operations such as record；Significantly
The personnel safety of test is improved, it is significant to shorten the testing time, operator's quantity is reduced, test operation is safe and accurate, fast
Speed, the present invention also have the characteristics that structure is simple, at low cost.
Detailed description of the invention
Fig. 1 is structural schematic diagram of the invention；
Fig. 2 is the additional capacitance measurement schematic diagram of neutral point；
Fig. 3 is the equivalent circuit diagram after the additional standard capacitance of neutral point；
Fig. 4 is the controller figure of neutral point Capacitive current tester；
Fig. 5 is attached to the wireless transmission receiving module figure of neutral point Capacitive current tester controller；
Fig. 6 is the basic circuit diagram of neutral point Capacitive current tester controller connection；
Fig. 7 is attached to the semiconductor diode circuit diagram that the forward voltage of controller in Fig. 4 is 320mV；
Fig. 8 is attached to the buzzer connection circuit diagram of controller in Fig. 4；
Fig. 9 is attached to the electric resistance touch screen interface circuit figure of controller in Fig. 4；
Figure 10 is attached to the indicator light circuit figure of controller in Fig. 4；
Figure 11 is attached to the circuit construction of electric power figure of controller in Fig. 4；
Figure 12 is attached to the parameter storage circuit diagram of controller in Fig. 4；
Figure 13 is handheld terminal controller schematic diagram；
Figure 14 is attached to the wirless transmitting and receiving module circuit diagram of controller in Figure 13；
Figure 15 is attached to the indicator light circuit figure of controller in Figure 13；
Figure 16 is attached to the semiconductor diode circuit diagram that the forward voltage of controller in Figure 13 is 320mV；
Figure 17 is attached to the buzzer circuit figure of controller in Figure 13；
Figure 18 is attached to the basic circuit diagram (reset circuit, wake-up circuit etc.) of controller in Figure 13；
Figure 19 is attached to the parameter storage circuit diagram of controller in Figure 13；
Figure 20 is attached to the touch screen interface circuit diagram of controller in Figure 13；
Figure 21 is attached to the power circuit diagram of controller in Figure 13.
Specific embodiment
With reference to the accompanying drawing and the present invention is described further in specific embodiment.
Embodiment 1: as shown in Fig. 1-Figure 21, a kind of isolated neutral system capacitance current test device, including neutrality
Point Capacitive current tester 1 and overhead jointing clamp 2, overhead jointing clamp 2 are connected to the test of neutral point capacitance current by p-wire 3
Instrument 1, the ground terminal of neutral point Capacitive current tester 1 are connected to handheld terminal by wireless module by the connection of ground wire 8 ground
4, overhead jointing clamp 2 is mounted in operating stick 5, and overhead jointing clamp 2 is articulated to neutral point bus 7 by operating operating stick 5
On.
Preferably, high-tension fuse 6 is connected between above-mentioned p-wire 3 and overhead jointing clamp 2, high-tension fuse 6 is fixed to be connected
It connects in operating stick 5.
Preferably, above-mentioned overhead jointing clamp model HS9300.
Neutral point Capacitive current tester 1 and handheld terminal are all made of 3.5 that DC32240B035_02 is a band touch
Very little resolution ratio is the basic model configuration industrial serial ports screen of 320*240, adapts to the yards such as adverse circumstances, strong magnetic disturbance and open air
It closes.User MCU only needs a serial ports that can easily realize that text, GUI, picture, animation are shown and the functions such as touch control.It produces
Product support a variety of common configuration controls: button control, text control, meter control, icon control, animation control, progress bar control
Part, slider control, dropdown menu controls, two dimensional code control and selection control etc., 99% program development amount are saved for user, very
Positive " What You See Is What You Get, zero code programming " is the optimal selection of new product development or the monochromatic screen of replacement.
A kind of embodiment 2: test method of isolated neutral system capacitance current test device, comprising the following steps:
(1) tester places neutral point Capacitive current tester 1 and powers on, and p-wire one end connects host terminals
Son, the other end are articulated to the neutral point exit of system under test (SUT) using hand-held insulating bar operation overhead jointing clamp；
(2) tester is remotely controlled the beginning measurement process of neutral point Capacitive current tester 1 by handheld terminal；
(3) neutral point Capacitive current tester 1 is automatically performed measurement process, measures asymmetrical voltage UHCWith displacement voltage U0
And it calculates capacitance current measurement result automatically and is uploaded to handheld terminal；
(4) tester's handheld terminal checks test data and saves result.
Formula of capacitive current is as follows in step (3):
IC=ω ∑ CxUφ
In formula, ∑ CxFor measured capacitance, ∑ Cx=CA+CB+CC, μ F, CA、CB、CCRespectively system under test (SUT) is three relatively electric
Hold；
C0For additional capacitor, μ F；
U0For displacement voltage, i.e., end voltage on capacitor, V；
UHCFor three relatively asymmetrical voltages, V；
ICFor the capacitance current of tested network, A；
ω is angular frequency；
UφFor power grid specified phase voltage, V.
Measuring principle: isolated neutral system Capacitive current tester measuring principle is using the neutrality in the indirect method of measurement
Additional capacitance method is put to measure the capacitance current of distribution.Measuring principle as shown in Fig. 2,
In Fig. 2, CA、CB, Cc be respectively system under test (SUT) three-phase ground capacitance, due to CA≠CB≠ Cc, therefore main transformer quilt
The neutral point of examining system side must have an asymmetrical voltage U over the groundHCIn the presence of.If one end of additional capacitor C0 is grounded, the other end
It is connected to the neutral point of main transformer system under test (SUT) side, then can be reduced to equivalent circuit as shown in Figure 3 by equivalent generator principle.
The capacitor and capacitance current value of tested network are obtained accordingly.
Measuring process: tester first opens neutral point Capacitive current tester working power switch, and p-wire is inserted into
The operating stick of neutral point Capacitive current tester patch jack, hand-held insulation connects test lead to system neutral, just leaves
Property point Capacitive current tester, hand-held terminal remote control neutral point Capacitive current tester, neutral point electricity are operated outside safe distance
Capacitance current tester completes the measurement of three relatively asymmetrical voltages according to remote control command, and neutral point Capacitive current tester is automatic
It is switched to built-in standard capacitor group and completes displacement voltage U0Measurement, capacitance current calculated according to formula automatically.
By wireless transmitter module built in neutral point Capacitive current tester, result is sent to handheld terminal, tester
Member's handheld test terminal checks measurement result, can be remotely controlled carry out repetition measurement, reach safety operation, the purpose accurately measured.
The present invention only needs tester to connect p-wire, and tester can complete in safety zone remote host
Measurement process, it is no longer necessary to which other testers cooperate wiring, reading, the manual operations such as record；Significantly improve the people of test
Member's safety, it is significant to shorten the testing time, operator's quantity is reduced, the method is safe and accurate, quick.
The present invention by the analysis to traditional measurement method, in conjunction with power electric component in recent years latest development at
Fruit carries out the upgrading that manual operation is automatically performed to device to entire test process with new device new paragon, needs original
The operating procedure being accomplished manually is changed to that device is allowed to be automatically performed by software, pass through theory analysis and simulated experiment, it was demonstrated that should
Method has higher measurement accuracy, the convenience of in-site measurement, and safety significantly improves, the significant work for mitigating tester
Amount, and safety precautions can be provided when ground fault occurs for system, improve the safety of tested distribution network systems.
The above description is merely a specific embodiment, but scope of protection of the present invention is not limited thereto, any
Those familiar with the art in the technical scope disclosed by the present invention, can easily think of the change or the replacement, and should all contain
Within protection scope of the present invention, therefore, protection scope of the present invention should be based on the protection scope of the described claims lid.
Claims (4)
1. a kind of isolated neutral system capacitance current test device, it is characterised in that: tested including neutral point capacitance current
Instrument (1) and jointing clamp (2), jointing clamp (2) are connected to neutral point Capacitive current tester (1) by p-wire (3), neutral point electricity
The ground terminal of capacitance current tester (1) connects ground, and is connected to handheld terminal (4) by wireless module, and jointing clamp (2) is mounted on
In operating stick (5).
2. a kind of isolated neutral system capacitance current test device according to claim 1, it is characterised in that: test
It is connected between line (3) and jointing clamp (2) high-tension fuse (6), high-tension fuse (6) is fixedly connected on operating stick (5).
3. a kind of test method of isolated neutral system capacitance current test device according to claim 1, special
Sign is: the following steps are included:
(1) tester places neutral point Capacitive current tester (1) and powers on, and p-wire one end connects host connecting terminal,
The other end is articulated to the neutral point exit of system under test (SUT) using hand-held insulating bar operation jointing clamp；
(2) tester starts measurement process by handheld terminal remote control neutral point Capacitive current tester (1)；
(3) neutral point Capacitive current tester (1) is automatically performed measurement process, measures asymmetrical voltage UHCWith displacement voltage U0And
The automatic capacitance current measurement result that calculates is uploaded to handheld terminal；
(4) tester's handheld terminal checks test data and saves result.
4. a kind of test method of isolated neutral system capacitance current test device according to claim 1, special
Sign is: formula of capacitive current is as follows in step (3):
IC=ω ∑ CxUφ
In formula, ∑ CxFor measured capacitance, ∑ Cx=CA+CB+CC, μ F, CA、CB、CCThe respectively three-phase ground capacitance of system under test (SUT)；
C0For additional capacitor, μ F；
U0For displacement voltage, i.e., end voltage on capacitor, V；
UHCFor three relatively asymmetrical voltages, V；
ICFor the capacitance current of tested network, A；
ω is angular frequency；
UφFor power grid specified phase voltage, V.
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| CN201811008153.5A CN109061276A (en) | 2018-08-31 | 2018-08-31 | A kind of isolated neutral system capacitance current test device and its test method |
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| CN201811008153.5A CN109061276A (en) | 2018-08-31 | 2018-08-31 | A kind of isolated neutral system capacitance current test device and its test method |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110736881A (en) * | 2019-10-30 | 2020-01-31 | 国网山西省电力公司阳泉供电公司 | Special capacitor current test operating rod |
| CN111562464A (en) * | 2020-05-12 | 2020-08-21 | 国网山东省电力公司电力科学研究院 | Parameter online testing method, storage medium and device of neutral point ungrounded system |
| CN112540321A (en) * | 2020-11-30 | 2021-03-23 | 广西电网有限责任公司电力科学研究院 | Novel power distribution network capacitance current measuring method and system |
| CN112557944A (en) * | 2020-11-18 | 2021-03-26 | 广西电网有限责任公司电力科学研究院 | Distribution network capacitance current test operating rod |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110736881A (en) * | 2019-10-30 | 2020-01-31 | 国网山西省电力公司阳泉供电公司 | Special capacitor current test operating rod |
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| CN112557944A (en) * | 2020-11-18 | 2021-03-26 | 广西电网有限责任公司电力科学研究院 | Distribution network capacitance current test operating rod |
| CN112540321A (en) * | 2020-11-30 | 2021-03-23 | 广西电网有限责任公司电力科学研究院 | Novel power distribution network capacitance current measuring method and system |
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