CN106291434A - The monitoring method of ground state of capacitance type potential transformer and system - Google Patents
The monitoring method of ground state of capacitance type potential transformer and system Download PDFInfo
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- CN106291434A CN106291434A CN201610951124.7A CN201610951124A CN106291434A CN 106291434 A CN106291434 A CN 106291434A CN 201610951124 A CN201610951124 A CN 201610951124A CN 106291434 A CN106291434 A CN 106291434A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
- G01R35/02—Testing or calibrating of apparatus covered by the other groups of this subclass of auxiliary devices, e.g. of instrument transformers according to prescribed transformation ratio, phase angle, or wattage rating
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
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Abstract
The present invention provides monitoring method and the system of an a kind of ground state of capacitance type potential transformer; when there is ball gap portable protective gaps in the primary side of capacitance type potential transformer; when the output fundamental voltage of the power transmission described capacitance type potential transformer secondary side of detection is from without becoming sometimes, determine that described capacitance type potential transformer puts into；The earth current of the secondary side voltage circuit of described capacitance type potential transformer is detected within the scheduled time that described capacitance type potential transformer puts into；When the electric current high fdrequency component during the first-harmonic of described earth current exceedes predetermined current threshold or described earth current exceedes the current harmonics threshold of setting, determine that the primary side of described capacitance type potential transformer is unearthed.Carry out the measurement of electric parameter at secondary side, thus effectively monitor the operating condition of primary side.
Description
Technical field
The present invention relates to electrical equipment safety monitoring technology field, particularly relate to a kind of capacitance type potential transformer and once connect
The monitoring method of ground state and system.
Background technology
Capacitance type potential transformer (CVT, Capacitor Voltage Transformers) is to be divided by series capacitor
Pressure, then through intermediate transformer blood pressure lowering and isolation.Specifically may refer to shown in Fig. 1, high-voltage capacitance C1 of series connection and middle voltage capacitance C2
Composition potentiometer.T is intermediate transformer, and L is compensation reactor, and J is capacitor grounding terminal, and X is reactor ground terminal.F1
It is over-voltage protection element with F2.D is antivibrator.
Current domestic 110kV grade capacitance type potential transformer occupancy about 80%, 220kV grade CVT occupancy is about
95%, 330kV and ratings above CVT occupancy 100%, along with the increase of unattended operation transformer station, need the on-line monitoring of CVT
Ask and can increase accordingly.In order to ensure CVT safe operation, the dielectric loss of periodically electric capacity each to CVT and capacitance is needed to survey
Amount, various metering systems are required to open capacitor grounding terminal J, and due to the low-voltage wiring terminal case of CVT, to be positioned at first and second special
, often there is the situation forgetting to recover capacitor grounding terminal ground in the point of interface of industry after single test.
If J does not recovers ground connection after single test, i.e. C2 is unearthed, and after CVT puts into operation, C2 will be in open circuit shape
State, the phase voltage of C1 and T sharing system.Owing to C1 capacitance is less, system phase voltage fully falls on T, causes the high-pressure side electricity of T
Position rises to system voltage.When C2 end shield does not punctures, the electric current flowing through C2 is 0, and C2 two terminal potential is equal, equal to T high-pressure side electricity
Pressure, now system voltage is by the end shield fully falling in C2.General CVT end shield ground terminal is pressure is not more than 4kV, fuel tank internal
C2 end shield is pressure is about 10kV, and under the conditions of unearthed, C2 end shield is by disruptive discharge.
In sum, in the case of C2 is earth-free, busbar voltage or line voltage distribution can all concentrate on unearthed end
On son, lasting electric discharge is caused to occur.When unearthed terminal arrangement during protection ball gap, electric discharge occurs in ball gap；When not connecing
When ground terminal is configured without protecting ball gap, or protection ball gap serious scaling loss is when can not play a protective role, electric discharge it may happen that
In middle pressure transformer or middle voltage capacitance fuel tank, cause fuel tank scaling loss leakage of oil, after running the most in spite of wound, CVT can be caused to explode,
Actual motion occurred due to the earth-free penetrability breakdown and explosion accident caused.
Therefore, those skilled in the art need to provide the monitoring method of an a kind of ground state of capacitance type potential transformer
And system, it is possible to it is accurately detected the primary side whether ground connection of CVT, thus ensures the safe operation of circuit.
Summary of the invention
In order to solve above technical problem present in prior art, the present invention also provides for a kind of capacitance type potential transformer
The monitoring method of ground state and system, be accurately detected the primary side whether ground connection of CVT, thus ensure the safety of circuit
Run.
The present invention provides the monitoring method of an a kind of ground state of capacitance type potential transformer, when capacitor voltage mutual inductance
When the primary side of device does not exist ball gap portable protective gaps, the method includes:
When the output fundamental voltage of the power transmission described capacitance type potential transformer secondary side of detection is from without becoming sometimes, determine institute
State capacitance type potential transformer to put into；
The secondary of described capacitance type potential transformer is detected within the scheduled time that described capacitance type potential transformer puts into
The earth current of side voltage circuit；
Electric current high fdrequency component in the first-harmonic of described earth current exceedes predetermined current threshold or described earth current surpasses
When crossing the current harmonics threshold set, determine that the primary side of described capacitance type potential transformer is unearthed.
The embodiment of the present invention also provides for the monitoring method of an a kind of ground state of capacitance type potential transformer, when a phase is female
There is a capacitance type potential transformer in line, and when the primary side of described capacitance type potential transformer exists ball gap portable protective gaps,
The method includes:
Obtain the voltage high frequency component in the output voltage of the secondary side of described capacitance type potential transformer before having a power failure；
After acquisition power transmission, in the scheduled time, the voltage in the output voltage of the secondary side of described capacitance type potential transformer is high
Frequency component；
When the voltage high frequency component after power transmission is more than M times of the voltage high frequency component before having a power failure, determine described condenser type
The primary side of voltage transformer is unearthed, and described M is predetermined constant.
Preferably, also include:
When the voltage high frequency component after the most described power transmission is all higher than voltage high frequency component M times before having a power failure
Time, then output alarm signal, inform that unearthed fault occurs in the primary side of described capacitance type potential transformer.
The embodiment of the present invention also provides for the monitoring method of an a kind of ground state of capacitance type potential transformer, works as transformer station
In a phase bus on following two capacitance type potential transformer at least in parallel: the first capacitance type potential transformer and the second electric capacity
Formula voltage transformer, the method includes:
The first output electricity of the secondary side of described first capacitance type potential transformer is detected in the scheduled time respectively after power transmission
Second output voltage of the secondary side of pressure and the second capacitance type potential transformer；
Obtain the first voltage high frequency component in described first output voltage and the electricity of second in described second output voltage
Pressure high fdrequency component；
When described first voltage high frequency component exceedes described second voltage high frequency component N times, and described first voltage high frequency
When component exceedes the voltage harmonic threshold of setting, it is determined that the primary side of described first capacitance type potential transformer is unearthed；Institute
Stating N is predetermined constant.
The embodiment of the present invention also provides for the monitoring system of an a kind of ground state of capacitance type potential transformer, works as condenser type
When the primary side of voltage transformer does not exist ball gap portable protective gaps, this system includes: secondary side output voltage transformer, secondary side
Earth current transformer and controller；
Described secondary side output voltage transformer, for detecting the output first-harmonic of described capacitance type potential transformer secondary side
Voltage is also sent to described controller；
Described secondary side earth current transformer, for detecting the secondary side voltage circuit of described capacitance type potential transformer
Earth current and be sent to controller；
Described controller, for when the output fundamental voltage of described capacitance type potential transformer secondary side is from without becoming having
Time, determine that described capacitance type potential transformer puts into, within the scheduled time that described capacitance type potential transformer puts into, judge institute
State the first-harmonic of earth current to exceed the electric current high fdrequency component in predetermined current threshold or described earth current and exceed the electric current of setting
During harmonic wave threshold, determine that the primary side of described capacitance type potential transformer is unearthed.
The embodiment of the present invention also provides for the monitoring system of an a kind of ground state of capacitance type potential transformer, works as condenser type
When the primary side of voltage transformer exists ball gap portable protective gaps, this system includes: secondary side output voltage transformer and controller；
Described secondary side output voltage transformer, for detecting the secondary side of the front described capacitance type potential transformer that has a power failure
Output voltage is also sent to described controller；It is additionally operable to detect after power transmission in the scheduled time the two of described capacitance type potential transformer
The output voltage of secondary side is also sent to described controller；
Described controller, for being obtained the voltage high frequency component before having a power failure and by power transmission by the output voltage before described power failure
After output voltage obtain the voltage high frequency component after power transmission, when the voltage high frequency component after power transmission is high more than the voltage before having a power failure
During M times of frequency component, determining that the primary side of described capacitance type potential transformer is unearthed, described M is predetermined constant.
Preferably, also include: alarm；
Described controller, is additionally operable to before the voltage high frequency component after the most described power transmission is all higher than having a power failure
Voltage high frequency component M times time, then control described alarm and report to the police.
The embodiment of the present invention also provides for the monitoring system of an a kind of ground state of capacitance type potential transformer, works as transformer station
In a phase bus on following two capacitance type potential transformer at least in parallel: the first capacitance type potential transformer and the second electric capacity
Formula voltage transformer, this system includes: the first output voltage transformer, the second output voltage transformer and controller；
Described first output voltage transformer, detects described first capacitor voltage mutual inductance after power transmission in the scheduled time
First output voltage of the secondary side of device is also sent to described controller；
Described second output voltage transformer unit, detects described second capacitor voltage mutual after power transmission in the scheduled time
Second output voltage of the secondary side of sensor is also sent to described controller；
Described controller, for obtaining the first voltage high frequency component in described first output voltage and described second output
The second voltage high frequency component in voltage；When described first voltage high frequency component exceedes described second voltage high frequency component N times, and
When described first voltage high frequency component exceedes the voltage harmonic threshold of setting, it is used for determining described first capacitance type potential transformer
Primary side unearthed；Described N is predetermined constant.
Compared with prior art, the present invention at least has the advantage that
When primary side exists ball gap portable protective gaps, when primary side is unearthed, by the protection electric discharge of ball gap, now secondary connects
There is harmonic component in earth-current.When primary side normal ground, the ground connection harmonic current of secondary side voltage circuit is the least.But
It is, when primary side is unearthed, big more than during normal ground of the ground connection harmonic current of secondary side voltage circuit, therefore, pass through
The ground connection harmonic current measuring secondary side voltage circuit may determine that primary side whether ground connection.When judging that primary side is unearthed,
Need to make alarm prompt, allow staff by primary side ground connection, thus ensure the properly functioning of capacitance type potential transformer.?
Secondary side carries out the measurement of electric parameter, thus effectively monitors the operating condition of primary side, lacks when finding that running occurs in primary side
When falling into, and alarm, to avoid secondary side equipment breakdown that primary side accident brings and personal safety accident to occur.Further, should
The enforcement of method can concentrate in indoor volume secondary screen cabinet, and during construction, power failure coverage is less, such as, can pass through voltage
The modes such as loop bridging realize not power cut construction.
Accompanying drawing explanation
In order to be illustrated more clearly that the embodiment of the present application or technical scheme of the prior art, below will be to embodiment or existing
In having technology to describe, the required accompanying drawing used is briefly described, it should be apparent that, the accompanying drawing in describing below is only this
Some embodiments described in application, for those of ordinary skill in the art, on the premise of not paying creative work,
Other accompanying drawing can also be obtained according to these accompanying drawings.
Fig. 1 is the connection diagram of CVT in prior art；
Embodiment of the method one flow chart that Fig. 2 provides for the present invention；
Embodiment of the method two flow chart that Fig. 3 provides for the present invention；
Embodiment of the method three flow chart that Fig. 4 provides for the present invention；
System embodiment one schematic diagram that Fig. 5 provides for the present invention；
System embodiment two schematic diagram that Fig. 6 provides for the present invention；
System embodiment three schematic diagram that Fig. 7 provides for the present invention.
Detailed description of the invention
In order to make those skilled in the art be more fully understood that the present invention program, below in conjunction with in the embodiment of the present invention
Accompanying drawing, is clearly and completely described the technical scheme in the embodiment of the present invention, it is clear that described embodiment is only this
Invent a part of embodiment rather than whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art exist
Do not make the every other embodiment obtained under creative work premise, broadly fall into the scope of protection of the invention.
Embodiment of the method one:
Seeing Fig. 2, this figure is that the monitoring method of the ground state of capacitance type potential transformer that the present invention provides is implemented
Example one flow chart.
The monitoring method of the ground state of capacitance type potential transformer that the present embodiment provides, when capacitor voltage mutual inductance
When the primary side of device does not exist ball gap portable protective gaps, the method includes:
S201: when the output fundamental voltage of described capacitance type potential transformer secondary side is from without becoming sometimes, determine described
Capacitance type potential transformer puts into；
S202: detect described capacitance type potential transformer within the scheduled time that described capacitance type potential transformer puts into
The earth current of secondary side voltage circuit；
S203: the electric current height frequency division in the first-harmonic of described earth current exceedes predetermined current threshold or described earth current
When amount exceedes the current harmonics threshold of setting, determine that the primary side of described capacitance type potential transformer is unearthed.
It is understood that when primary side does not exist ball gap portable protective gaps, when primary side is unearthed, secondary can only be passed through
The N of side discharges, and when i.e. primary side is unearthed, when system power transmission CVT puts into operation, secondary side earth current will substantially increase
Greatly.
In order to judge that primary side is unearthed more accurately, the present embodiment adds detection CVT secondary side earth current
Time restriction condition, i.e. detects the earth current of secondary side rather than after CVT has been put into for a long time when CVT just puts into
Detect again.Due to secondary side earth current change possibly also owing to that the otherwise fault of system causes rather than by
Cause in CVT primary side is unearthed.And only when CVT just puts into, primary side is unearthed, then the earth current meeting of secondary side
There is significantly change.
It addition, the earth current change of secondary side voltage circuit can be judged by two aspects, it is on the one hand earth current
Size have and significantly become big, i.e. exceed predetermined current threshold, then it is believed that primary side is unearthed.On the other hand, it is also possible to
Being judged by the electric current high fdrequency component in earth current, when the electric current high fdrequency component in earth current, to exceed the electric current of setting humorous
During ripple threshold, then it is believed that primary side is unearthed.
Because when primary side normal ground, the ground connection harmonic current of secondary side voltage circuit is the least, the most properly functioning
Time, earth current is the power current of 50Hz.But, when primary side is unearthed, the ground connection harmonic wave electricity of secondary side voltage circuit
That flows more than during normal ground is big, therefore, by measuring the electric current high fdrequency component in the earth current of secondary side voltage circuit also
May determine that primary side whether ground connection.When judging that primary side is unearthed, need to make alarm prompt, allow the staff will once
Side joint ground, thus ensure the properly functioning of capacitance type potential transformer.
It should be noted that high fdrequency component refers to the harmonic component in electric current.
It addition, current harmonics threshold can set according to actual needs, during primary side normal ground, secondary side voltage returns
The earth current on road is power current, and high fdrequency component can be the least.Therefore, as long as secondary side voltage circuit exists certain high frequency and connects
Earth-current, then may determine that primary side is unearthed.
Embodiment of the method two:
Seeing Fig. 3, this figure is that the monitoring method of the ground state of capacitance type potential transformer that the present invention provides is implemented
Example two flow chart.
The monitoring method of the ground state of capacitance type potential transformer that the present embodiment provides, capacitance type potential transformer
Primary side when there is ball gap portable protective gaps, the method includes:
S301: the voltage high frequency obtained before having a power failure in the output voltage of the secondary side of described capacitance type potential transformer divides
Amount；
S302: the electricity in the output voltage of the secondary side of described capacitance type potential transformer in the scheduled time after acquisition power transmission
Pressure high fdrequency component；
S303: when the voltage high frequency component after power transmission is more than M times of the voltage high frequency component before having a power failure, determine described electricity
The primary side of appearance formula voltage transformer is unearthed, and described M is predetermined constant.
In the present embodiment, when its primary side whether ground connection is judged for single CVT, take the mode of longitudinal comparison, i.e.
The voltage high frequency component of the secondary side output voltage before being had a power failure by this CVT and after power failure compares.
It should be noted that when the primary side of capacitance type potential transformer exists ball gap portable protective gaps, by measuring two
The earth current of secondary side voltage circuit can not be accurately judged to primary side whether ground connection, therefore, passes through secondary in the present embodiment
The output voltage of side judges primary side whether ground connection.
It is understood that when the primary side of capacitance type potential transformer exists ball gap portable protective gaps, and primary side is not
During ground connection, the output voltage of secondary side is not sinusoidal wave, but there is the waveform being distorted of high fdrequency component.Therefore, it can
Whether there is high fdrequency component by detection secondary side output voltage and judge primary side whether ground connection.
It addition, in order to avoid harmonic component when CVT puts into is disturbed, CVT can be escaped by the way of adding long delay and throws
Fashionable transient process, it is to avoid alarm by mistake.
It addition, in order to avoid by mistake alarm, the method that the present embodiment provides, also include the following step postponing alarm:
When the most described voltage high frequency component all exceedes the voltage harmonic threshold of setting, then export warning
Signal, informs that unearthed fault occurs in the primary side of described capacitance type potential transformer.
That is, it is all higher than the voltage high frequency component before having a power failure when the voltage high frequency component after the most described power transmission
When M times, then it is assumed that the output voltage of the secondary side that primary side is unearthed rather than instantaneous interference causes exists voltage high frequency and divides
Amount.
Embodiment of the method three:
Seeing Fig. 4, this figure is that the monitoring method of the ground state of capacitance type potential transformer that the present invention provides is implemented
Example three flow chart.
The monitoring method that the present embodiment provides, it is adaptable to when on the phase bus in transformer station in parallel two or more
During CVT, the unearthed CVT of primary side can be accurately measured.During for multiple CVT, take the mode of lateral comparison, the most multiple
Compare between CVT voltage high frequency component mutually.
Being introduced as a example by two CVT below, method during two or more CVT is similar to, and does not repeats them here.
The monitoring method of the ground state of capacitance type potential transformer that the present embodiment provides, when the phase in transformer station
Following two capacitance type potential transformer at least in parallel on bus: the first capacitance type potential transformer and the second capacitor voltage are mutual
Sensor, the method includes:
S401: detect secondary side first defeated of described first capacitance type potential transformer after power transmission in the scheduled time respectively
Go out the second output voltage of the secondary side of voltage and the second capacitance type potential transformer；
S402: obtain in the first voltage high frequency component in described first output voltage and described second output voltage
Two voltage high frequency components；
S403: when described first voltage high frequency component exceedes described second voltage high frequency component N times, and described first voltage
When high fdrequency component exceedes the voltage harmonic threshold of setting, it is determined that the primary side of described first capacitance type potential transformer does not connects
Ground；Described N is predetermined constant.
It is understood that the method that the present embodiment provides, two CVT are taked the mode of lateral comparison, it is judged that one
The unearthed CVT in secondary side.
It should be noted that when there being two CVT to be connected in parallel on a phase bus, no matter whether the primary side of CVT exists ball
Gap is protected, and all can be accurately judged to primary side whether ground connection by detection secondary side voltage high frequency component.
Such as, it is secondary corresponding for another CVT when the high fdrequency component of secondary side output voltage corresponding for one of them CVT
When 10 times of the high fdrequency component of side output voltage or 20 times, then the primary side of the CVT that explanation high fdrequency component is big is unearthed.
It is understood that the concrete numerical value of N can be arranged according to actual needs.
The monitoring method that above example of the present invention provides, monitors electric parameter by the secondary side at CVT, can be accurate
Judge primary side whether ground connection.When specifically can measure CVT primary side normal ground in advance, the electric parameter measuring secondary side is made
For the reference quantity judged.In time being embodied as, the electric parameter of secondary side can be detected in real time, compare with reference quantity, from
And judge primary side whether ground connection.
Whether above example of the present invention exists two kinds of situations of ball gap point for CVT primary side, exists for primary side
During ball gap, primary side whether ground connection can be judged by the earth current of detection secondary side voltage circuit.For primary side not
When there is ball gap, primary side whether ground connection can be judged by detection secondary side output voltage.
It addition, the method that above example of the present invention provides is the least for the transformation of existing line and equipment, it is beneficial to promote
Application.The measurement of electric parameter i.e. on the basis of existing equipment, can be carried out at secondary side, thus effectively monitor primary side
Operating condition, when finding that operational defect occurs in primary side, and alarm, with the secondary side equipment avoiding primary side accident to bring
Accident and personal safety accident occur.Further, the enforcement of the method can concentrate in indoor secondary screen cabinet, has a power failure during construction
Coverage is less, such as, can realize not power cut construction by modes such as voltage circuit bridgings.
Monitoring method based on the ground state of a kind of capacitance type potential transformer that above example provides, the present invention
Embodiment also provides for the monitoring system of an a kind of ground state of capacitance type potential transformer, carries out detailed below in conjunction with the accompanying drawings
Introduce.
System embodiment one:
Seeing Fig. 5, this figure is system embodiment one schematic diagram that the present invention provides.
The monitoring system of the ground state of capacitance type potential transformer that the present embodiment provides, when capacitor voltage mutual inductance
When the primary side of device does not exist ball gap portable protective gaps, this system includes: secondary side output voltage transformer 501, secondary side ground connection
Current transformer 502 and controller 503；
Secondary side output voltage transformer 501, for detecting the output first-harmonic of described capacitance type potential transformer secondary side
Voltage is also sent to described controller；
Described secondary side earth current transformer 502, for detecting the secondary side voltage of described capacitance type potential transformer
The earth current in loop is also sent to controller；
Described controller unit 503, for when the output fundamental voltage of described capacitance type potential transformer secondary side is by without becoming
For sometimes, determine that described capacitance type potential transformer puts into, sentence within the scheduled time that described capacitance type potential transformer puts into
The electric current high fdrequency component that the first-harmonic of disconnected described earth current exceedes in predetermined current threshold or described earth current exceedes setting
During current harmonics threshold, determine that the primary side of described capacitance type potential transformer is unearthed.
It is understood that when primary side does not exist ball gap portable protective gaps, when primary side is unearthed, secondary can only be passed through
The N of side discharges, and when i.e. primary side is unearthed, when system power transmission CVT puts into operation, secondary side earth current will substantially increase
Greatly.
In order to judge that primary side is unearthed more accurately, the present embodiment adds detection CVT secondary side earth current
Time restriction condition, i.e. detects the earth current of secondary side rather than after CVT has been put into for a long time when CVT just puts into
Detect again.Due to secondary side earth current change possibly also owing to that the otherwise fault of system causes rather than by
Cause in CVT primary side is unearthed.And only when CVT just puts into, primary side is unearthed, then the earth current meeting of secondary side
There is significantly change.
It addition, the earth current change of secondary side voltage circuit can be judged by two aspects, it is on the one hand earth current
Size have and significantly become big, i.e. exceed predetermined current threshold, then it is believed that primary side is unearthed.On the other hand, it is also possible to
Being judged by the electric current high fdrequency component in earth current, when the electric current high fdrequency component in earth current, to exceed the electric current of setting humorous
During ripple threshold, then it is believed that primary side is unearthed.
Because when primary side normal ground, the ground connection harmonic current of secondary side voltage circuit is the least, the most properly functioning
Time, earth current is the power current of 50Hz.But, when primary side is unearthed, the ground connection harmonic wave electricity of secondary side voltage circuit
That flows more than during normal ground is big, therefore, by measuring the electric current high fdrequency component in the earth current of secondary side voltage circuit also
May determine that primary side whether ground connection.When judging that primary side is unearthed, need to make alarm prompt, allow the staff will once
Side joint ground, thus ensure the properly functioning of capacitance type potential transformer.
It addition, current harmonics threshold can set according to actual needs, during primary side normal ground, secondary side voltage returns
The earth current on road is power current, and high fdrequency component can be the least.Therefore, as long as secondary side voltage circuit exists certain high frequency and connects
Earth-current, then may determine that primary side is unearthed.
System embodiment two:
Seeing Fig. 6, this figure is system embodiment two schematic diagram that the present invention provides.
The monitoring system of the ground state of capacitance type potential transformer that the present embodiment provides, when capacitor voltage mutual inductance
When the primary side of device exists ball gap portable protective gaps, this system includes: secondary side output voltage transformer 601 and controller 602；
Described secondary side output voltage transformer 601, for detecting the secondary of the front described capacitance type potential transformer that has a power failure
The output voltage of side is also sent to described controller；It is additionally operable to detect after power transmission described capacitance type potential transformer in the scheduled time
The output voltage of secondary side and be sent to described controller；
Described controller 602, for by before described power failure output voltage obtain have a power failure before voltage high frequency component and by
Output voltage after power transmission obtains the voltage high frequency component after power transmission, when the voltage high frequency component after power transmission is more than the electricity before having a power failure
When pressing M times of high fdrequency component, determining that the primary side of described capacitance type potential transformer is unearthed, described M is predetermined constant.
It should be noted that when the primary side of capacitance type potential transformer exists ball gap portable protective gaps, by measuring two
The earth current of secondary side voltage circuit can not be accurately judged to primary side whether ground connection, therefore, passes through secondary in the present embodiment
The output voltage of side judges primary side whether ground connection.
It is understood that when the primary side of capacitance type potential transformer exists ball gap portable protective gaps, and primary side is not
During ground connection, the output voltage of secondary side is not sinusoidal wave, but there is the waveform being distorted of high fdrequency component.Therefore, it can
Whether there is high fdrequency component by detection secondary side output voltage and judge primary side whether ground connection.
It addition, in order to avoid harmonic component when CVT puts into is disturbed, CVT can be escaped by the way of adding long delay and throws
Fashionable transient process, it is to avoid alarm by mistake.
It addition, in order to avoid alarm by mistake, the system that the present embodiment provides, it is also possible to including: alarm；
Also include: alarm；
Described controller, is additionally operable to before the voltage high frequency component after the most described power transmission is all higher than having a power failure
Voltage high frequency component M times time, then control described alarm and report to the police.
That is, when the persistent period of voltage high frequency component exceedes predetermined amount of time, then it is assumed that primary side unearthed rather than
There is voltage high frequency component in the output voltage of the secondary side that instantaneous interference causes.
System embodiment three:
Seeing Fig. 7, this figure is system embodiment three schematic diagram that the present invention provides.
The monitoring system that the present embodiment provides, it is adaptable to as two CVT in parallel on the phase bus in transformer station, permissible
Measure the unearthed CVT of primary side.
The monitoring system of the ground state of capacitance type potential transformer that the present embodiment provides, when the phase in transformer station
Following two capacitance type potential transformer at least in parallel on bus: the first capacitance type potential transformer and the second capacitor voltage are mutual
Sensor, this system includes: the first output voltage transformer the 701, second output voltage transformer 702 and controller 703；
Described first output voltage transformer 701, detects described first capacitor voltage after power transmission in the scheduled time
First output voltage of the secondary side of transformer is also sent to described controller；
Described second output voltage transformer 702, detects described second capacitor voltage after power transmission in the scheduled time
Second output voltage of the secondary side of transformer is also sent to described controller；
Described controller, for obtaining the first voltage high frequency component in described first output voltage and described second output
The second voltage high frequency component in voltage；When described first voltage high frequency component exceedes described second voltage high frequency component N times, and
When described first voltage high frequency component exceedes the voltage harmonic threshold of setting, it is used for determining described first capacitance type potential transformer
Primary side unearthed；Described N is predetermined constant.
Such as, it is secondary corresponding for another CVT when the high fdrequency component of secondary side output voltage corresponding for one of them CVT
When 10 times of the high fdrequency component of side output voltage or 20 times, then the primary side of the CVT that explanation high fdrequency component is big is unearthed.
It is understood that the concrete numerical value of N can be arranged according to actual needs.
The monitoring system that above example of the present invention provides, monitors electric parameter by the secondary side at CVT, can be accurate
Judge primary side whether ground connection.When specifically can measure CVT primary side normal ground in advance, the electric parameter measuring secondary side is made
For the reference quantity judged.In time being embodied as, the electric parameter of secondary side can be detected in real time, compare with reference quantity, from
And judge primary side whether ground connection.
Whether above example of the present invention exists two kinds of situations of ball gap point for CVT primary side, exists for primary side
During ball gap, primary side whether ground connection can be judged by the earth current of detection secondary side voltage circuit.For primary side not
When there is ball gap, primary side whether ground connection can be judged by detection secondary side output voltage.
It addition, the system that above example of the present invention provides is the least for the transformation of existing line and equipment, it is beneficial to promote
Application.The measurement of electric parameter i.e. on the basis of existing equipment, can be carried out at secondary side, thus effectively monitor primary side
Operating condition, when finding that operational defect occurs in primary side, and alarm, with the secondary side equipment avoiding primary side accident to bring
Accident and personal safety accident occur.Further, this system can be with in concentrated setting secondary screen cabinet indoors, power failure shadow during construction
The scope of sound is less, such as, can realize not power cut construction by modes such as voltage circuit bridgings.
The above, be only presently preferred embodiments of the present invention, and the present invention not makees any pro forma restriction.Though
So the present invention is disclosed above with preferred embodiment, but is not limited to the present invention.Any it is familiar with those skilled in the art
Member, without departing under technical solution of the present invention ambit, may utilize the method for the disclosure above and technology contents to the present invention
Technical scheme makes many possible variations and modification, or is revised as the Equivalent embodiments of equivalent variations.Therefore, every without departing from
The content of technical solution of the present invention, the technical spirit of the foundation present invention is to any simple modification made for any of the above embodiments, equivalent
Change and modification, all still fall within the range of technical solution of the present invention protection.
Claims (8)
1. the monitoring method of ground state of a capacitance type potential transformer, it is characterised in that when capacitor voltage mutual inductance
When the primary side of device does not exist ball gap portable protective gaps, the method includes:
When the output fundamental voltage of the power transmission described capacitance type potential transformer secondary side of detection is from without becoming sometimes, determine described electricity
Appearance formula voltage transformer puts into；
The secondary side electricity of described capacitance type potential transformer is detected within the scheduled time that described capacitance type potential transformer puts into
Push back the earth current on road；
Electric current high fdrequency component in the first-harmonic of described earth current exceedes predetermined current threshold or described earth current exceedes and sets
During fixed current harmonics threshold, determine that the primary side of described capacitance type potential transformer is unearthed.
2. the monitoring method of ground state of a capacitance type potential transformer, it is characterised in that when a phase bus exists
Individual capacitance type potential transformer, and when the primary side of described capacitance type potential transformer exists ball gap portable protective gaps, the method bag
Include:
Obtain the voltage high frequency component in the output voltage of the secondary side of described capacitance type potential transformer before having a power failure；
After obtaining power transmission, in the scheduled time, the voltage high frequency in the output voltage of the secondary side of described capacitance type potential transformer divides
Amount；
When the voltage high frequency component after power transmission is more than M times of the voltage high frequency component before having a power failure, determine described capacitor voltage
The primary side of transformer is unearthed, and described M is predetermined constant.
The monitoring method of ground state of capacitance type potential transformer the most according to claim 2, it is characterised in that also
Including:
When the voltage high frequency component after the most described power transmission is all higher than voltage high frequency component M times before having a power failure,
Then output alarm signal, informs that unearthed fault occurs in the primary side of described capacitance type potential transformer.
4. the monitoring method of ground state of a capacitance type potential transformer, it is characterised in that when the phase in transformer station
Following two capacitance type potential transformer at least in parallel on bus: the first capacitance type potential transformer and the second capacitor voltage are mutual
Sensor, the method includes:
Detect respectively in the scheduled time after power transmission described first capacitance type potential transformer secondary side the first output voltage and
Second output voltage of the secondary side of the second capacitance type potential transformer；
Obtain the second voltage in the first voltage high frequency component in described first output voltage and described second output voltage high
Frequency component；
When described first voltage high frequency component exceedes described second voltage high frequency component N times, and described first voltage high frequency component
When exceeding the voltage harmonic threshold of setting, it is determined that the primary side of described first capacitance type potential transformer is unearthed；Described N is
Predetermined constant.
5. the monitoring system of ground state of a capacitance type potential transformer, it is characterised in that when capacitor voltage mutual inductance
When the primary side of device does not exist ball gap portable protective gaps, this system includes: secondary side output voltage transformer, secondary side earth current
Transformer and controller；
Described secondary side output voltage transformer, for detecting the output fundamental voltage of described capacitance type potential transformer secondary side
And it is sent to described controller；
Described secondary side earth current transformer, for detecting connecing of the secondary side voltage circuit of described capacitance type potential transformer
Earth-current is also sent to controller；
Described controller, for when the output fundamental voltage of described capacitance type potential transformer secondary side is from without becoming sometimes, really
Fixed described capacitance type potential transformer puts into, and judges described ground connection within the scheduled time that described capacitance type potential transformer puts into
The first-harmonic of electric current exceedes the electric current high fdrequency component in predetermined current threshold or described earth current and exceedes the current harmonics door of setting
During sill, determine that the primary side of described capacitance type potential transformer is unearthed.
6. the monitoring system of ground state of a capacitance type potential transformer, it is characterised in that when capacitor voltage mutual inductance
When the primary side of device exists ball gap portable protective gaps, this system includes: secondary side output voltage transformer and controller；
Described secondary side output voltage transformer, for detecting the output of the secondary side of the front described capacitance type potential transformer that has a power failure
Voltage is also sent to described controller；It is additionally operable to detect after power transmission the secondary side of described capacitance type potential transformer in the scheduled time
Output voltage and be sent to described controller；
Described controller, for by before described power failure output voltage obtain have a power failure before voltage high frequency component and by power transmission after
Output voltage obtains the voltage high frequency component after power transmission, when the voltage high frequency component after power transmission divides more than the voltage high frequency before having a power failure
Amount M times time, determine that the primary side of described capacitance type potential transformer is unearthed, described M is predetermined constant.
The monitoring system of ground state of capacitance type potential transformer the most according to claim 6, it is characterised in that also
Including: alarm；
Described controller, is additionally operable to when the voltage high frequency component after the most described power transmission is all higher than the electricity before having a power failure
During pressure high fdrequency component M times, then control described alarm and report to the police.
8. the monitoring system of ground state of a capacitance type potential transformer, it is characterised in that when the phase in transformer station
Following two capacitance type potential transformer at least in parallel on bus: the first capacitance type potential transformer and the second capacitor voltage are mutual
Sensor, this system includes: the first output voltage transformer, the second output voltage transformer and controller；
Described first output voltage transformer, detects described first capacitance type potential transformer after power transmission in the scheduled time
First output voltage of secondary side is also sent to described controller；
Described second output voltage transformer unit, detects described second capacitance type potential transformer after power transmission in the scheduled time
The second output voltage of secondary side and be sent to described controller；
Described controller, for obtaining the first voltage high frequency component in described first output voltage and described second output voltage
In the second voltage high frequency component；When described first voltage high frequency component exceedes described second voltage high frequency component N times and described
When first voltage high frequency component exceedes the voltage harmonic threshold of setting, for determining the one of described first capacitance type potential transformer
Secondary side is unearthed；Described N is predetermined constant.
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| CN201610951124.7A CN106291434B (en) | 2016-10-26 | 2016-10-26 | Method and system for monitoring primary grounding state of capacitive voltage transformer |
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| CN106772200A (en) * | 2017-01-25 | 2017-05-31 | 云南电网有限责任公司电力科学研究院 | CVT error in dipping anomaly assessment method and system based on capacitive earth current |
| CN109839531A (en) * | 2019-02-19 | 2019-06-04 | 国网陕西省电力公司电力科学研究院 | A kind of capacitance type potential transformer and its Transmission Characteristics system and operating method |
| CN110824405A (en) * | 2019-10-30 | 2020-02-21 | 国网新疆电力有限公司哈密供电公司 | System and method for detecting amplitude-frequency characteristics of capacitor voltage transformer |
| CN112327236A (en) * | 2020-11-16 | 2021-02-05 | 润电能源科学技术有限公司 | Method for monitoring capacitive voltage transformer on line and related equipment |
| CN112986667A (en) * | 2021-02-22 | 2021-06-18 | 国网陕西省电力公司电力科学研究院 | Voltage digital signal measuring method and system for CVT voltage quality measurement |
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| CN112986667A (en) * | 2021-02-22 | 2021-06-18 | 国网陕西省电力公司电力科学研究院 | Voltage digital signal measuring method and system for CVT voltage quality measurement |
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