CN108562827A - A kind of small current earthing wire-selecting method and system - Google Patents
A kind of small current earthing wire-selecting method and system Download PDFInfo
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- CN108562827A CN108562827A CN201810204539.7A CN201810204539A CN108562827A CN 108562827 A CN108562827 A CN 108562827A CN 201810204539 A CN201810204539 A CN 201810204539A CN 108562827 A CN108562827 A CN 108562827A
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- simulating grid
- current earthing
- mode
- grid
- simulating
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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
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
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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
Abstract
The invention discloses a kind of small current earthing wire-selecting methods, including：Receive the analog signal and digital signal of simulating grid output；Wherein, the simulating grid is the simulated grid for simulating actual electric network operating condition built in advance；The analog signal is amplified, and analog signal is sent to Small Electric Current Earthing And Routing Device by treated；Coupling isolation is carried out to the digital signal, and digital signal is sent to Small Electric Current Earthing And Routing Device by treated；The Small Electric Current Earthing And Routing Device judges the faulty line of the simulating grid, and sends control instruction to the simulating grid, so that the simulating grid controls faulty line described in circuit breaker trip according to the control instruction.The invention also discloses a kind of Little Current Ground Connection Systems.Embodiment using the present invention can realize the actual operating mode to break down when simulation small current earthing wire-selecting, accurately reflect the operation characteristic of small current earthing wire-selecting.
Description
Technical field
The present invention relates to Relay Protection Technology in Power System field more particularly to a kind of small current earthing wire-selecting method and it is
System.
Background technology
Small current earthing wire-selecting is a kind of protection equipment that power industry uses, and is suitable for neutral point through resistance or arc blowout wire
The single-phase grounding selecting for enclosing earthed system, for substation, power plant, power station and the chemical industry of electric system, oil recovery, metallurgy,
The power supply system of the large factories and mines enterprises such as coal, railway is able to indicate that the circuit that singlephase earth fault occurs.Electric system
Neutral grounding mode is a comprehensive technical problem, its power supply reliability with system, personal safety, equipment safety,
, there is close relationship in the problems such as dielectric level, overvoltage protection, relay protection, Communication Jamming and earthing or grounding means.But with
The continuous development of national economy, power distribution network scale increasingly expand, in power distribution network operational process, existing small current earthing wire-selecting
Power distribution network in singlephase earth fault it is multiple, although regulation allow fault condition under can also continue to operation one to two hours,
The non-faulting phase voltage of whole system is increased to line voltage, if handling not in time, easily causes phase fault, influence power supply can
By property.
Invention content
The purpose of the embodiment of the present invention is to provide a kind of small current earthing wire-selecting method and system, can realize the small electricity of simulation
The actual operating mode to break down when earthing wire-selecting is flowed, accurately reflects the operation characteristic of small current earthing wire-selecting.
To achieve the above object, the embodiment of the present invention provides a kind of small current earthing wire-selecting method, including：
Receive the analog signal and digital signal of simulating grid output；Wherein, the simulating grid is the use built in advance
In the simulated grid of simulation actual electric network operating condition；
The analog signal is amplified, and analog signal is sent to Small Electric Current Earthing And Routing Device by treated；
Coupling isolation is carried out to the digital signal, and digital signal is sent to small current earthing wire-selecting dress by treated
It sets；
The Small Electric Current Earthing And Routing Device is according to treated the analog signal and described treated that number is believed
Number judge the faulty line of the simulating grid, and sends control instruction to the simulating grid, so that the simulating grid root
According to faulty line described in control instruction control circuit breaker trip.
Compared with prior art, a kind of small current earthing wire-selecting method disclosed by the embodiments of the present invention is by building simulation electricity
Net, and it is sent to the small current earthing wire-selecting after the analog signal and digital signal that the simulating grid exports are handled
Device so that the Small Electric Current Earthing And Routing Device judges the faulty line of the simulating grid, and sends control instruction to institute
Simulating grid is stated, the simulating grid controls faulty line described in circuit breaker trip according to the control instruction.It solves existing
Singlephase earth fault is multiple in the power distribution network of existing small current earthing wire-selecting in technology, causes phase fault, influences power supply
The problem of reliability, can realize the actual operating mode to break down when simulation small current earthing wire-selecting, accurately reflect
The operation characteristic of small current earthing wire-selecting.
As the improvement of said program, the analog signal includes ac voltage signal and current signal, the number letter
Number be the breaker position signal.
As the improvement of said program, the analogue ground mode of the simulating grid include isolated neutral mode, in
Property point is through grounding through arc mode, arc grounding mode or three-phase imbalance earthing mode；Wherein,
When the analogue ground mode of the simulating grid is the isolated neutral mode, the mother of the simulating grid
Line is connect with leak resistance；
When the analogue ground mode of the simulating grid is the three-phase imbalance earthing mode, in the busbar of any phase
Place's connection ground capacity, so that the voltage deviation that the capacitance generates simulates three-phase imbalance.
As the improvement of said program, the Small Electric Current Earthing And Routing Device is cut according to breaker described in round cut function control
Disconnected faulty line, the round cut function include fixed round cut pattern and automatic round cut pattern, wherein
The fixed round cut pattern is to carry out disengagement failure circuit according to the sequence of preset disengagement failure circuit；It is described from
The driving wheel pattern of cutting is the overhead line being initially switched off in the simulating grid, then cuts off the cable in the simulating grid.
As the improvement of said program, the Small Electric Current Earthing And Routing Device breaks according to described in rear Accelerated trip function control
Road device disengagement failure circuit, the rear Accelerated trip function is after the faulty line in the simulating grid trips, default
When time internal fault circuit closes a floodgate again, the Small Electric Current Earthing And Routing Device controls the circuit breaker trip faulty line.
To achieve the above object, the embodiment of the present invention also provides a kind of Little Current Ground Connection System, including：
Analogue simulation device for obtaining simulating grid, and makes the simulating grid control breaker according to control instruction
Cut off the faulty line；Wherein, the simulating grid is the emulation for simulating actual electric network operating condition built in advance
Power grid；
Interface equipment, analog signal and digital signal for receiving the simulating grid output, and the simulation is believed
Number it is sent to power amplification device, the digital signal is sent to relay；
Power amplification device, for the analog signal to be amplified, and will treated that analog signal is sent to is small
Current earthing line selection apparatus；
Relay, for the digital signal to be carried out coupling isolation, and digital signal is sent to small electricity by treated
Flow line-selected earthing device；
Small Electric Current Earthing And Routing Device, for according to treated the analog signal and treated the number letter
Number judge the faulty line of the simulating grid, and sends control instruction to the interface equipment, so that the interface equipment will
The control instruction is sent to the analogue simulation device.
Compared with prior art, a kind of Little Current Ground Connection System disclosed by the embodiments of the present invention passes through the emulation mould
Quasi- device obtains simulating grid, then is handled by the analog signal that the power amplification device exports the simulating grid
After be sent to the Small Electric Current Earthing And Routing Device, the digital signal exported to the simulating grid by the relay carries out
The Small Electric Current Earthing And Routing Device is sent to after processing, so that the Small Electric Current Earthing And Routing Device judges the simulating grid
Faulty line, and send control instruction to the simulating grid, the simulating grid controls open circuit according to the control instruction
Device cuts off the faulty line.Solves singlephase earth fault in the power distribution network of existing small current earthing wire-selecting in the prior art
It is multiple, the problem of causing phase fault, influence the reliability of power supply, break down when can realize simulation small current earthing wire-selecting
Actual operating mode, accurately reflect the operation characteristic of small current earthing wire-selecting.
As the improvement of said program, the Little Current Ground Connection System further includes simulation work station, the emulation work
It stands for building the simulating grid, and the parameter of the simulating grid is set；The analog signal includes alternating voltage letter
Number and current signal, the digital signal be the breaker position signal.
As the improvement of said program, the analogue ground mode of the simulating grid include isolated neutral mode, in
Property point is through grounding through arc mode, arc grounding mode or three-phase imbalance earthing mode；Wherein,
When the analogue ground mode of the simulating grid is the isolated neutral mode, the mother of the simulating grid
Line is connect with leak resistance；
When the analogue ground mode of the simulating grid is the three-phase imbalance earthing mode, in the busbar of any phase
Place's connection ground capacity, so that the voltage deviation that the capacitance generates simulates three-phase imbalance.
As the improvement of said program, the Small Electric Current Earthing And Routing Device is cut according to breaker described in round cut function control
Disconnected faulty line, the round cut function include fixed round cut pattern and automatic round cut pattern, wherein
The fixed round cut pattern is to carry out disengagement failure circuit according to the sequence of preset disengagement failure circuit；It is described from
The driving wheel pattern of cutting is the overhead line being initially switched off in the simulating grid, then cuts off the cable in the simulating grid.
As the improvement of said program, the Small Electric Current Earthing And Routing Device breaks according to described in rear Accelerated trip function control
Road device disengagement failure circuit, the rear Accelerated trip function is after the faulty line in the simulating grid trips, default
When time internal fault circuit closes a floodgate again, the Small Electric Current Earthing And Routing Device controls the circuit breaker trip faulty line.
Description of the drawings
Fig. 1 is a kind of flow chart of small current earthing wire-selecting method provided in an embodiment of the present invention；
Fig. 2 is a kind of structure of the isolated neutral mode of small current earthing wire-selecting method provided in an embodiment of the present invention
Schematic diagram；
Fig. 3 is a kind of neutral by arc extinction coil grounding side of small current earthing wire-selecting method provided in an embodiment of the present invention
The structural schematic diagram of formula；
Fig. 4 is a kind of neutral by arc extinction coil grounding side of small current earthing wire-selecting method provided in an embodiment of the present invention
The structural schematic diagram of arc suppression coil in formula；
Fig. 5 is a kind of showing for the three-phase imbalance earthing mode of small current earthing wire-selecting method provided in an embodiment of the present invention
It is intended to；
Fig. 6 is a kind of structural schematic diagram of Little Current Ground Connection System provided in an embodiment of the present invention；
Fig. 7 is the structural schematic diagram of interface equipment in a kind of Little Current Ground Connection System provided in an embodiment of the present invention.
Specific implementation mode
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete
Site preparation describes, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on
Embodiment in the present invention, those of ordinary skill in the art are obtained every other without creative efforts
Embodiment shall fall within the protection scope of the present invention.
Embodiment one
It is a kind of flow chart of small current earthing wire-selecting method provided in an embodiment of the present invention referring to Fig. 1, Fig. 1；Including：
S1, the analog signal and digital signal for receiving simulating grid output；Wherein, the simulating grid is built in advance
Simulated grid for simulating actual electric network operating condition；
S2, the analog signal is amplified, and analog signal is sent to small current earthing wire-selecting dress by treated
It sets；
S3, coupling isolation is carried out to the digital signal, and digital signal is sent to small current neutral grounding choosing by treated
Line apparatus；
S4, the Small Electric Current Earthing And Routing Device are according to treated the analog signal and treated the number
Signal judges the faulty line of the simulating grid, and sends control instruction to the simulating grid, so that the simulating grid
Faulty line described in circuit breaker trip is controlled according to the control instruction.
Wherein, the analog signal includes ac voltage signal and current signal, and the digital signal is the breaker
Position signal.
Specifically, in step sl, the simulating grid can be received by interface equipment or other signal receivers
The analog signal and digital signal of output.Preferably, the interface equipment includes analog output interface circuit board, digital output
Interface board sum number word amount input interface board；Wherein, the analog output interface circuit board receives the analog signal, described
Digital-quantity output interface board receives the digital signal, and the digital-quantity input interface board is received for controlling the simulation
The control instruction of grid disruption road device.
Specifically, in step s 2, can be amplified to the analog signal by power amplification device, due to receiving
The ac voltage signal and the current signal very little, the power amplification device play the analog signal of output
The effect of amplification, preferably to simulate practical small current earthing wire-selecting mode.
Specifically, in step s3, can be carried out to the digital signal by relay or other coupling isolating devices
Coupling isolation, the function that the relay has coupling isolation input part, drives output par, c, fills small current earthing wire-selecting
It sets and plays control, protection, adjusting and transmit information function.
Specifically, in step s 4, the Small Electric Current Earthing And Routing Device according to treated the analog signal and
Treated digital signal the judges faulty line of the simulating grid, failure be separate and fault type, and sends control
Instruction is to the simulating grid, so that the simulating grid controls fault wire described in circuit breaker trip according to the control instruction
Road.Preferably, the control instruction is digital quantity signal.
Preferably, the simulating grid can be obtained by analogue simulation device, and the analogue simulation device is able to record
Experimental data and recording when the simulating grid is run in small current earthing wire-selecting mode.The analogue simulation device can be with
It is RTDS (real-time digital simulator).
Preferably, the simulating grid can be built by the simulation work station of power grid, it is preferred that the simulation work station
It can be computer.Faulty line can also be arranged in the small current earthing wire-selecting mode of simulation in the simulating grid, so as to
In more really simulating actual small current earthing wire-selecting mode.The simulation electricity can also be arranged in the simulation work station
The parameter of net.The small current neutral grounding of the analogue simulation device simulation can also be shown on the display interface of the simulation work station
Operating status, the waveform etc. of earth fault occur for simulating grid described in line selection mode.Specifically, the analogue simulation device will
The information such as operating parameter, waveform when the simulating grid that analogue simulation goes out breaks down are sent to the simulation work station, pass through
The simulation work station comes out these presentation of information, is conducive to human-computer interaction.
Preferably, the simulating grid includes infinitely great power supply, transformer, busbar, branch, load and control module.
The analogue ground mode of the preferred simulating grid includes isolated neutral mode, neutral by arc extinction coil grounding side
Formula, arc grounding mode and three-phase imbalance earthing mode.
When the analogue ground mode of the simulating grid is the isolated neutral mode, referring to Fig. 2, including busbar
Ia, busbar IIa, infinitely great power supply V1, transformer T1, branch Tline and load, wherein branch 1, branch 10 and branch
14 be overhead line, and branch 5 and branch 9 are cable, and branch 7 and branch 15 are overhead line and cable.The simulating grid
Busbar is connect with leak resistance.When the simulating grid continuous fault, the leak resistance plays snapback voltage amplitude
With the effect of operating status, shorten recovery time after failure, is capable of the operation characteristic of the more preferable simulation low current mode of connection.
When the analogue ground mode of the simulating grid is the neutral by arc extinction coil grounding mode, referring to Fig. 3,
Including busbar Ib, busbar IIb, infinitely great power supply V2, transformer T2, branch Tline, load and arc suppression coil 100, wherein
Branch 1, branch 10 and branch 14 are overhead line, and branch 5 and branch 9 are cable, branch 7 and branch 15 be overhead line and
Cable.Wherein, the arc suppression coil 100 in the mode through grounding through arc includes inductance L, resistance R and damper switch S,
The structure of the arc suppression coil 100 can be found in Fig. 4, and the inductance L is used to simulate the inductance of turn-adjusting arc-extinguishing winding, the resistance
R is used to simulate the equivalent loss of arc suppression coil, it is preferred that the size of the inductance L can be according to the simulating grid to ground connection
The size of the electric current of capacitance and tuning-off degree determine.The arc suppression coil 100 is more than 5A using inductance current than capacity current
Overcompensation mode, the loss of the arc suppression coil 100 takes the 1% of the arc suppression coil capacity.
When property point is through grounding through arc mode in simulations, the control strategy used to the arc suppression coil 100 includes：
When failure starts, when the control unit of the arc suppression coil 100 detects that neutral point voltage is more than 30% phase voltage, the extinguishing arc
100 sending action signal of coil controls the damper switch S and is closed, and the arc suppression coil starts compensating for.It is described after Failure elimination
The control unit of arc suppression coil 100 needs to detect the variation of neutral point voltage again, is only less than 30% phase in neutral point voltage
When voltage, the actuating signal of the arc suppression coil 100 can just send out the instruction for exiting compensation.
When the analogue ground mode of the simulating grid is the arc grounding mode, accessing one in abort situation can
Become resistance, arc resistance is simulated using variable resistance, the variable resistance is using arc current as output variable, to export electricity
Arc resistance is as output quantity.
When the analogue ground mode of the simulating grid is the three-phase imbalance earthing mode, using in any phase mother
Ground capacity is connected at line, is simulated three-phase imbalance to generate the mode of voltage deviation, is set according to capacitance size
Surely the size for carrying out three-phase imbalance can verify that Small Electric Current Earthing And Routing Device is run accurate under the conditions of three-phase imbalance
Property.As shown in figure 5, in the three-phase imbalance earthing mode, including A phase, B phase, C phase and ground capacity C1, the A phases
It is connect with the first end of the ground capacity C1, the second end ground connection of the ground capacity C1.
Preferably, the Small Electric Current Earthing And Routing Device carries out disengagement failure line according to breaker described in round cut function control
Road, the round cut function include fixed round cut pattern and automatic round cut pattern, wherein the fixed round cut pattern is according to default
Disengagement failure circuit sequence carry out disengagement failure circuit；The automatic round cut pattern is to be initially switched off in the simulating grid
Overhead line, then cut off the cable in the simulating grid.
Specifically, round cut function refers under tripping failure and less than two kinds operating modes of protection sensitivity, according to round cut strategy
Pattern come cut off in turn circuit until excision faulty line.When circuit is under the operating mode of tripping failure, wheel can be directly initiated
Function is cut come the excision faulty line that trips；When circuit is in the insufficient operating mode of protection sensitivity, the protection sensitivity is insufficient
It the case where referring to when the residual voltage of the Small Electric Current Earthing And Routing Device is less than fault line detection definite value, can be opened through being delayed
The round cut function in long time limit is moved, which can throw and move back, and delay duration can manually be set.Preferably, the round cut strategy pattern packet
Fixed round cut pattern and automatic round cut pattern are included, the fixed round cut pattern refers to by the suitable of artificial preset disengagement failure circuit
Sequence carries out disengagement failure circuit；The automatic round cut pattern is the overhead line being initially switched off in the simulating grid, then is cut off described
Cable in simulating grid, wherein same type circuit presses the failure rate of Small Electric Current Earthing And Routing Device statistics from high to low
Sequence carries out round cut circuit.
The present invention is provided with route selection tripping failure or the insufficient operating mode of protection sensitivity in the simulating grid, when described
After Small Electric Current Earthing And Routing Device starts round cut function, whenever the breaker of a circuit is because receiving the small current neutral grounding choosing
The trip signal of line apparatus and when tripping, the circuit breaker switch state of the circuit is exported to described by the relay
Small Electric Current Earthing And Routing Device, to provide simulated conditions for round cut function.In the present embodiment, the ground resistance of failure is set
Residual voltage when line fault is set to meet condition：Fault line detection definite value is more than residual voltage, and residual voltage is more than round cut definite value.
Wherein, the fault line detection definite value is the startup voltage of the Small Electric Current Earthing And Routing Device, that is, when the simulating grid
When singlephase earth fault occurs, the minimum voltage of the Small Electric Current Earthing And Routing Device start-up operation can be made；The zero sequence electricity
Pressure is the residual voltage of Small Electric Current Earthing And Routing Device sampling, determines whether the Small Electric Current Earthing And Routing Device starts；
The round cut definite value is a threshold value of the Small Electric Current Earthing And Routing Device inner setting, when the fault line detection definite value is big
In the residual voltage, when the residual voltage is more than the round cut definite value, the Small Electric Current Earthing And Routing Device just starts wheel
Cut function.
Preferably, the Small Electric Current Earthing And Routing Device is according to circuit breaker trip failure described in rear Accelerated trip function control
Circuit, the rear Accelerated trip function is after the faulty line in the simulating grid trips, in preset time internal fault line
When road is closed a floodgate again, the Small Electric Current Earthing And Routing Device controls the circuit breaker trip faulty line.The present invention is in the mould
The operating mode that circuit closes a floodgate again is provided in quasi- power grid, i.e., in the Small Electric Current Earthing And Routing Device by a certain line tripping
Afterwards, the simulating grid closes a floodgate after the set time after the line tripping again automatically, and by the relay by circuit
The on off state of breaker export to the Small Electric Current Earthing And Routing Device, the Small Electric Current Earthing And Routing Device judge again be
Accelerated trip function after no satisfaction.In the present embodiment, the set time closed a floodgate again is preferably 1.5 seconds.
Compared with prior art, a kind of small current earthing wire-selecting method disclosed by the embodiments of the present invention passes through the emulation mould
Quasi- device obtains simulating grid, then is handled by the analog signal that the power amplification device exports the simulating grid
After be sent to the Small Electric Current Earthing And Routing Device, the digital signal exported to the simulating grid by the relay carries out
The Small Electric Current Earthing And Routing Device is sent to after processing, so that the Small Electric Current Earthing And Routing Device judges the simulating grid
Faulty line, and send control instruction to the simulating grid, the simulating grid controls open circuit according to the control instruction
Device cuts off the faulty line.Solves singlephase earth fault in the power distribution network of existing small current earthing wire-selecting in the prior art
It is multiple, the problem of causing phase fault, influence the reliability of power supply, break down when can realize simulation small current earthing wire-selecting
Actual operating mode, accurately reflect the operation characteristic of small current earthing wire-selecting, ground for Small Electric Current Earthing And Routing Device
Study carefully and a kind of emulation platform is provided.
Embodiment two
It is a kind of structural schematic diagram of Little Current Ground Connection System provided in an embodiment of the present invention referring to Fig. 6, Fig. 6；Packet
It includes：
Analogue simulation device 21 for obtaining simulating grid, and makes the simulating grid control open circuit according to control instruction
Device cuts off the faulty line；Wherein, the simulating grid is to be built in advance for simulating the imitative of actual electric network operating condition
True power grid；
Interface equipment 22, analog signal and digital signal for receiving simulating grid output, and by the simulation
Signal is sent to power amplification device, and the digital signal is sent to relay；
Power amplification device 23, for the analog signal to be amplified, and by treated, analog signal is sent to
Small Electric Current Earthing And Routing Device 25；
Relay 24, for the digital signal to be carried out coupling isolation, and will treated that digital signal is sent to is small
Current earthing line selection apparatus 25；
Small Electric Current Earthing And Routing Device 25, for according to treated the analog signal and treated the number
Signal judges the faulty line of the simulating grid, and sends control instruction to the interface equipment 22, so that the interface is set
The control instruction is sent to the analogue simulation device 21 by standby 22；
For building the simulating grid, and the parameter of the simulating grid is arranged in simulation work station 26.
Wherein, the analog signal includes ac voltage signal and current signal, and the digital signal is the breaker
Position signal.
Specifically, the interface equipment 22 is separately connected the analogue simulation device 21, the power amplification device 23, institute
State relay 24 and the Small Electric Current Earthing And Routing Device 25, wherein referring to Fig. 7, the interface equipment 22 includes analog quantity
Output interface board 221, digital-quantity output interface board 222 and digital-quantity input interface board 223；Wherein, the analog quantity
Output interface board 221 receives the analog signal and the analog signal is sent to the power amplification device 23, described
Digital-quantity output interface board 222 receives the digital signal and the digital signal is sent to the relay 24, described
Digital-quantity input interface board 223 receives the control instruction for controlling breaker in the simulating grid.
Specifically, the power amplification device 23 is connect with the Small Electric Current Earthing And Routing Device 25, the power amplification
Equipment 23 is amplified the analog signal, the ac voltage signal due to reception and the current signal very little, institute
The analog signal of output can be amplified by stating power amplification device 23, preferably to simulate practical small current earthing wire-selecting
Mode.
Specifically, the relay 24 is connect with the Small Electric Current Earthing And Routing Device 25, the relay 24 is to described
Digital signal carries out coupling isolation, the function that the relay 24 has coupling isolation input part, drives output par, c, to institute
Small Electric Current Earthing And Routing Device 25 is stated to play control, protection, adjusting and transmit information function.Preferably, the relay 24 can
To be terminal-type relay.
Specifically, after the Small Electric Current Earthing And Routing Device 25 is according to treated the analog signal and the processing
Digital signal judge that the faulty line of the simulating grid, failure be separate and fault type, and send control instruction to described
Interface equipment 22, so that the control instruction is sent to the analogue simulation device 21 by the interface equipment 22, to described
The simulating grid in analogue simulation device 21 controls faulty line described in circuit breaker trip according to the control instruction.It is preferred that
, the control instruction is digital quantity signal.
Preferably, the simulating grid can be obtained by analogue simulation device 21, and the analogue simulation device 21 can
Record the experimental data and recording when the simulating grid is run in small current earthing wire-selecting mode.The analogue simulation device
21 can be RTDS (real-time digital simulator).
Preferably, the simulating grid can be built by the simulation work station 26 of power grid, it is preferred that the simulation work
Stand 26 can be computer.Faulty line can also be arranged in the small current earthing wire-selecting mode of simulation in the simulating grid,
In order to more really simulate actual small current earthing wire-selecting mode.The simulation work station 26 can also be arranged described
The parameter of simulating grid.It can also show what the analogue simulation device 21 was simulated on the display interface of the simulation work station 26
Operating status, the waveform etc. of earth fault occur for simulating grid described in small current earthing wire-selecting mode.Specifically, the emulation
The information such as operating parameter, waveform when simulator 21 breaks down the simulating grid that analogue simulation goes out are sent to the emulation
These presentation of information are come out by the simulation work station 26, are conducive to human-computer interaction by work station 26.
Preferably, the simulating grid includes infinitely great power supply, transformer, busbar, branch, load and control module.
The analogue ground mode of the preferred simulating grid includes isolated neutral mode, neutral by arc extinction coil grounding side
Formula, arc grounding mode and three-phase imbalance earthing mode.
When the analogue ground mode of the simulating grid is the isolated neutral mode, referring to Fig. 2, including busbar
Ia, busbar IIa, infinitely great power supply V1, transformer T1, branch Tline and load, wherein branch 1, branch 10 and branch
14 be overhead line, and branch 5 and branch 9 are cable, and branch 7 and branch 15 are overhead line and cable.The simulating grid
Busbar is connect with leak resistance.When the simulating grid continuous fault, the leak resistance plays snapback voltage amplitude
With the effect of operating status, shorten recovery time after failure, is capable of the operation characteristic of the more preferable simulation low current mode of connection.
When the analogue ground mode of the simulating grid is the neutral by arc extinction coil grounding mode, referring to Fig. 3,
Including busbar Ib, busbar IIb, infinitely great power supply V2, transformer T2, branch Tline, load and arc suppression coil 100, wherein
Branch 1, branch 10 and branch 14 are overhead line, and branch 5 and branch 9 are cable, branch 7 and branch 15 be overhead line and
Cable.Wherein, the arc suppression coil 100 in the mode through grounding through arc includes inductance L, resistance R and damper switch S,
The structure of the arc suppression coil 100 can be found in Fig. 4, and the inductance L is used to simulate the inductance of turn-adjusting arc-extinguishing winding, the resistance
R is used to simulate the equivalent loss of arc suppression coil, it is preferred that the size of the inductance L can be according to the simulating grid to ground connection
The size of the electric current of capacitance and tuning-off degree determine.The arc suppression coil 100 is more than 5A using inductance current than capacity current
Overcompensation mode, the loss of the arc suppression coil 100 takes the 1% of the arc suppression coil capacity.
When property point is through grounding through arc mode in simulations, the control strategy used to the arc suppression coil 100 includes：
When failure starts, when the control unit of the arc suppression coil 100 detects that neutral point voltage is more than 30% phase voltage, the extinguishing arc
100 sending action signal of coil controls the damper switch S and is closed, and the arc suppression coil starts compensating for.It is described after Failure elimination
The control unit of arc suppression coil 100 needs to detect the variation of neutral point voltage again, is only less than 30% phase in neutral point voltage
When voltage, the actuating signal of the arc suppression coil 100 can just send out the instruction for exiting compensation.
When the analogue ground mode of the simulating grid is the arc grounding mode, accessing one in abort situation can
Become resistance, arc resistance is simulated using variable resistance, the variable resistance is using arc current as output variable, to export electricity
Arc resistance is as output quantity.
When the analogue ground mode of the simulating grid is the three-phase imbalance earthing mode, using in any phase mother
Ground capacity is connected at line, is simulated three-phase imbalance to generate the mode of voltage deviation, is set according to capacitance size
Surely the size for carrying out three-phase imbalance can verify that the Small Electric Current Earthing And Routing Device 25 was run under the conditions of three-phase imbalance
Accuracy.As shown in figure 5, in the three-phase imbalance earthing mode, including A phase, B phase, C phase and ground capacity C1, institute
It states A phases to connect with the first end of the ground capacity C1, the second end ground connection of the ground capacity C1.
Preferably, the Small Electric Current Earthing And Routing Device 25 carries out disengagement failure according to breaker described in round cut function control
Circuit, the round cut function include fixed round cut pattern and automatic round cut pattern, wherein the fixed round cut pattern is according to pre-
If disengagement failure circuit sequence carry out disengagement failure circuit；The automatic round cut pattern is to be initially switched off in the simulating grid
Overhead line, then cut off the cable in the simulating grid.
Specifically, round cut function refers under tripping failure and less than two kinds operating modes of protection sensitivity, according to round cut strategy
Pattern come cut off in turn circuit until excision faulty line.When circuit is under the operating mode of tripping failure, wheel can be directly initiated
Function is cut come the excision faulty line that trips；When circuit is in the insufficient operating mode of protection sensitivity, the protection sensitivity is insufficient
The case where referring to when the residual voltage of the Small Electric Current Earthing And Routing Device 25 is less than fault line detection definite value can come through being delayed
Start the round cut function in long time limit, which can throw and move back, and delay duration can manually be set.Preferably, the round cut strategy pattern
Including fixed round cut pattern and automatic round cut pattern, the fixed round cut pattern refers to by artificial preset disengagement failure circuit
Sequence carries out disengagement failure circuit；The automatic round cut pattern is the overhead line being initially switched off in the simulating grid, then cuts off institute
State the cable in simulating grid, wherein the failure rate that same type circuit is counted by the Small Electric Current Earthing And Routing Device 25 is by height
Round cut circuit is carried out to low sequence.
The present invention is provided with route selection tripping failure or the insufficient operating mode of protection sensitivity in the simulating grid, when described
After Small Electric Current Earthing And Routing Device 25 starts round cut function, whenever the breaker of a circuit is because receiving the small current neutral grounding
The trip signal of line selection apparatus 25 and when tripping, the circuit breaker switch state of the circuit is exported by the relay 24
To the Small Electric Current Earthing And Routing Device 25, to provide simulated conditions for round cut function.In the present embodiment, failure is set
Ground resistance makes residual voltage when line fault meet condition：Fault line detection definite value is more than residual voltage, and residual voltage is more than
Round cut definite value.Wherein, the fault line detection definite value is the startup voltage of the Small Electric Current Earthing And Routing Device 25, that is, works as institute
When stating simulating grid generation singlephase earth fault, the minimum that the Small Electric Current Earthing And Routing Device 25 is started to work can be made electric
Pressure；The residual voltage is the residual voltage that the Small Electric Current Earthing And Routing Device 25 samples, and determines the small current neutral grounding choosing
Whether line apparatus 25 starts；The round cut definite value is a threshold value of 25 inner setting of the Small Electric Current Earthing And Routing Device,
When the fault line detection definite value is more than the residual voltage, and the residual voltage is more than the round cut definite value, the low current
Line-selected earthing device 25 just starts round cut function.
Preferably, the Small Electric Current Earthing And Routing Device 25 is according to circuit breaker trip event described in rear Accelerated trip function control
Hinder circuit, the rear Accelerated trip function is after the faulty line in the simulating grid trips, in preset time internal fault
When circuit closes a floodgate again, the Small Electric Current Earthing And Routing Device 25 controls the circuit breaker trip faulty line.The present invention is in institute
It states and is provided with the operating mode closed a floodgate again of circuit in simulating grid, i.e., in the Small Electric Current Earthing And Routing Device 25 by a certain circuit
After tripping, the simulating grid closes a floodgate after the set time after the line tripping again automatically, and passes through the relay 24
The on off state of the breaker of circuit is exported to the Small Electric Current Earthing And Routing Device 25, the Small Electric Current Earthing And Routing Device
25 judge whether Accelerated trip function after meeting again.In the present embodiment, the set time closed a floodgate again is preferably 1.5 seconds.
Compared with prior art, a kind of Little Current Ground Connection System disclosed by the embodiments of the present invention passes through the emulation mould
Quasi- device 21 obtains simulating grid, then is carried out to the analog signal that the simulating grid exports by the power amplification device 23
The Small Electric Current Earthing And Routing Device 25 is sent to after processing, the number exported to the simulating grid by the relay 24
Signal is sent to the Small Electric Current Earthing And Routing Device 25 after being handled, so that the Small Electric Current Earthing And Routing Device 25 judges
The faulty line of the simulating grid, and control instruction is sent to the simulating grid, the simulating grid is according to the control
Faulty line described in instruction control circuit breaker trip.It solves in the power distribution network of existing small current earthing wire-selecting in the prior art
Singlephase earth fault is multiple, causes phase fault, influence power supply reliability the problem of, can realize simulation small current neutral grounding choosing
The actual operating mode to break down when line accurately reflects the operation characteristic of small current earthing wire-selecting.
The above is the preferred embodiment of the present invention, it is noted that for those skilled in the art
For, various improvements and modifications may be made without departing from the principle of the present invention, these improvements and modifications are also considered as
Protection scope of the present invention.
Claims (10)
1. a kind of small current earthing wire-selecting method, which is characterized in that including：
Receive the analog signal and digital signal of simulating grid output；Wherein, the simulating grid is to be built in advance for mould
The simulated grid of quasi- actual electric network operating condition；
The analog signal is amplified, and analog signal is sent to Small Electric Current Earthing And Routing Device by treated；
Coupling isolation is carried out to the digital signal, and digital signal is sent to Small Electric Current Earthing And Routing Device by treated；
The Small Electric Current Earthing And Routing Device is according to treated the analog signal and described treated that digital signal is sentenced
The faulty line of the disconnected simulating grid, and control instruction is sent to the simulating grid, so that the simulating grid is according to institute
State faulty line described in control instruction control circuit breaker trip.
2. small current earthing wire-selecting method as described in claim 1, which is characterized in that the analog signal includes alternating voltage
Signal and current signal, the digital signal are the position signal of the breaker.
3. small current earthing wire-selecting method as described in claim 1, which is characterized in that the analogue ground side of the simulating grid
Formula includes isolated neutral mode, neutral by arc extinction coil grounding mode, arc grounding mode or three-phase imbalance ground connection
Mode；Wherein,
When the analogue ground mode of the simulating grid be the isolated neutral mode when, the busbar of the simulating grid with
Leak resistance connects；
When the analogue ground mode of the simulating grid is the three-phase imbalance earthing mode, connect at the busbar of any phase
Ground capacity is connect, so that the voltage deviation that the capacitance generates simulates three-phase imbalance.
4. small current earthing wire-selecting method as described in claim 1, which is characterized in that the Small Electric Current Earthing And Routing Device is pressed
According to circuit breaker trip faulty line described in round cut function control, the round cut function includes fixed round cut pattern and automatic round cut mould
Formula, wherein
The fixed round cut pattern is to carry out disengagement failure circuit according to the sequence of preset disengagement failure circuit；The automatic wheel
The pattern of cutting is the overhead line being initially switched off in the simulating grid, then cuts off the cable in the simulating grid.
5. small current earthing wire-selecting method as described in claim 1, which is characterized in that the Small Electric Current Earthing And Routing Device is pressed
According to circuit breaker trip faulty line described in rear Accelerated trip function control, the rear Accelerated trip function is when the simulating grid
In faulty line tripping after, when preset time internal fault circuit closes a floodgate again, Small Electric Current Earthing And Routing Device control
The circuit breaker trip faulty line.
6. a kind of Little Current Ground Connection System, which is characterized in that including：
Analogue simulation device for obtaining simulating grid, and makes the simulating grid control circuit breaker trip according to control instruction
The faulty line；Wherein, the simulating grid is the simulated grid for simulating actual electric network operating condition built in advance；
Interface equipment, analog signal and digital signal for receiving the simulating grid output, and the analog signal is sent out
Power amplification device is given, the digital signal is sent to relay；
Power amplification device, for the analog signal to be amplified, and by treated, analog signal is sent to low current
Line-selected earthing device；
Relay, for the digital signal to be carried out coupling isolation, and will treated that digital signal is sent to low current connects
Ground line selection apparatus；
Small Electric Current Earthing And Routing Device, for according to treated the analog signal and described treated that digital signal is sentenced
The faulty line of the disconnected simulating grid, and control instruction is sent to the interface equipment, so that the interface equipment will be described
Control instruction is sent to the analogue simulation device.
7. Little Current Ground Connection System as claimed in claim 5, which is characterized in that the Little Current Ground Connection System is also
Including simulation work station, the parameter of the simulating grid is arranged for building the simulating grid in the simulation work station；Institute
It includes ac voltage signal and current signal to state analog signal, and the digital signal is the position signal of the breaker.
8. Little Current Ground Connection System as claimed in claim 5, which is characterized in that the analogue ground side of the simulating grid
Formula includes isolated neutral mode, neutral by arc extinction coil grounding mode, arc grounding mode or three-phase imbalance ground connection
Mode；Wherein,
When the analogue ground mode of the simulating grid be the isolated neutral mode when, the busbar of the simulating grid with
Leak resistance connects；
When the analogue ground mode of the simulating grid is the three-phase imbalance earthing mode, connect at the busbar of any phase
Ground capacity is connect, so that the voltage deviation that the capacitance generates simulates three-phase imbalance.
9. Little Current Ground Connection System as claimed in claim 5, which is characterized in that the Small Electric Current Earthing And Routing Device is pressed
According to circuit breaker trip faulty line described in round cut function control, the round cut function includes fixed round cut pattern and automatic round cut mould
Formula, wherein
The fixed round cut pattern is to carry out disengagement failure circuit according to the sequence of preset disengagement failure circuit；The automatic wheel
The pattern of cutting is the overhead line being initially switched off in the simulating grid, then cuts off the cable in the simulating grid.
10. Little Current Ground Connection System as claimed in claim 5, which is characterized in that the Small Electric Current Earthing And Routing Device
According to circuit breaker trip faulty line described in rear Accelerated trip function control, the rear Accelerated trip function is when simulation electricity
After faulty line tripping in net, when preset time internal fault circuit closes a floodgate again, the Small Electric Current Earthing And Routing Device control
Make the circuit breaker trip faulty line.
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| CN201810204539.7A CN108562827A (en) | 2018-03-13 | 2018-03-13 | A kind of small current earthing wire-selecting method and system |
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|---|---|---|---|
| CN201810204539.7A CN108562827A (en) | 2018-03-13 | 2018-03-13 | A kind of small current earthing wire-selecting method and system |
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| CN110046443A (en) * | 2019-04-23 | 2019-07-23 | 南方电网科学研究院有限责任公司 | A kind of low-current ground fault line selection appraisal procedure and system |
| CN110161443A (en) * | 2019-05-16 | 2019-08-23 | 南方电网科学研究院有限责任公司 | A kind of small current earthing wire-selecting test device and its test method |
| CN111474466A (en) * | 2019-01-23 | 2020-07-31 | 本德尔有限两合公司 | Circuit arrangement for detecting closed switch contacts and for protecting ground conductor against interruption in single-phase or polyphase supply lines |
| CN111736091A (en) * | 2020-05-27 | 2020-10-02 | 湖南省湘电试验研究院有限公司 | Unstable high-resistance ground fault simulation circuit based on RTDS platform and application method thereof |
| CN112736869A (en) * | 2020-12-23 | 2021-04-30 | 贵州电网有限责任公司 | Fault alternate switching method of low-current grounding line selection device |
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