CN104076243A - Method for detection and indication of single-phase ground faults of small current grounding power distribution network and device - Google Patents

Method for detection and indication of single-phase ground faults of small current grounding power distribution network and device Download PDF

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Publication number
CN104076243A
CN104076243A CN201310106380.2A CN201310106380A CN104076243A CN 104076243 A CN104076243 A CN 104076243A CN 201310106380 A CN201310106380 A CN 201310106380A CN 104076243 A CN104076243 A CN 104076243A
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phase
current
voltage
fault
feeder line
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CN104076243B (en
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唐先武
张建良
李金鳌
臧红卫
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Yinghantong Jiaxing Communication Technology Co., Ltd.
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BEIJING INHAND NETWORK TECHNOLOGY Co Ltd
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Priority claimed from FIEP14772927.1T external-priority patent/FI2985613T3/en
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Abstract

A small current grounding mode is mainly adopted in power distribution networks in China and other countries. Most faults of a small current grounding power distribution network are single-phase high resistance ground faults, transient state capacitance current signals generated in the fault process are low in amplitude, short in time of duration and high in fault detection difficulty, and an effective fault detection and indication device is not available. The invention discloses a method for detection and indication of faults of the small current grounding power distribution network and a feeder line monitoring unit device. An electricity taking device with the power control function supplies power to feeder line monitoring units, voltage signals are collected through a capacitance type voltage sensor, current signals are collected through an electronic type current sensor, after suspected ground faults are detected, the other two phases are synchronously triggered in a wireless mode, and data are transmitted in a time division multiplexing wireless communication mode; after three-phase feeder line monitoring unit data of multiple points are gathered on system master station platform software, ground fault detection is conducted according to calculated zero-sequence voltages and calculated zero-sequence currents, and fault signals are issued to the feeder line monitoring unit in front of the fault point on the fault phase for fault indication.

Description

A kind of small current neutral grounding one-phase earthing failure in electric distribution network detects indicating means and equipment
Technical field
The present invention relates generally to the fault detect instruction of feeder automation part in power distribution automation, the method and apparatus that detects, indicates especially for small current neutral grounding one-phase earthing failure in electric distribution network.
Background technology
In electric system, power supply is from generating plant, and be sent to load side by high pressure or EHV transmission network, then by the lower network of electric pressure power distribution the user to different electric pressures, this network that mainly plays distribution electric energy effect in power network is just called distribution network, is called for short power distribution network.In electric system, power distribution network is the short slab that affects customer power supply reliability.The investment relative deficiency of power distribution network, automatization level is low, is a very weak link, and there is this problem countries in the world, and in China, this problem is more outstanding.According to the statistics of 2009, deduction short of electricity factor, the power off time of Chinese user more than 95% is all caused by power distribution network at present.
The common fault of power distribution network mainly contains short trouble and earth fault.Short trouble comprises three-phase shortcircuit and line to line fault, and earth fault common type is singlephase earth fault.For very ripe in the detection technique of short trouble, and for the detection of singlephase earth fault, particularly for the singlephase earth fault of small current neutral grounding power distribution network, also lack at present effective method, be acknowledged as global problem.
China and some national power distribution networks mostly are small current neutral grounding power distribution network, and most faults are all singlephase earth faults.Small current neutral grounding power distribution network major advantage is: when singlephase earth fault, do not form short-circuit loop, only produce very little ground current in system, three-phase line voltage is still symmetrical, does not affect the normal work of system.China Power code regulation, while there is singlephase earth fault, small current neutral grounding power distribution network can continue operation 1~2h by tape jam.The reliability that can improve like this power supply, is widely used.
But after generation singlephase earth fault, must find as early as possible Single-phase Ground Connection Failure, fix a breakdown.Otherwise the superpotential that earth fault produces, the power system accident such as can cause electric cable explosion, voltage transformer pt to burn, bus burns.If ground path is used as regular link long-time running simultaneously, bring great hidden danger can to local resident, safety of livestock.2010, there is distribution overhead line single-phase high resistance ground long-time running in Hechi City, Guangxi, causes the person accident of getting an electric shock and dying.This type of serious accident case happens occasionally, and has greatly threatened power grid security production.
The earthing mode of small current neutral grounding power distribution network is mainly earth-free and through grounding through arc.According to DL/T620-1997 " overvoltage protection of alternating-current electric device and Insulation Coordination "; pure overhead transmission line or pole line are mixed to the 10kV distribution forming with cable; if capacitance current when earth fault is less than 10A; can adopt earth-free mode; but when capacitance current is greater than 10A, just must installing arc suppression coil.
Power distribution network adopts isolated neutral or through grounding through arc mode, in the time there is singlephase earth fault, can not produce large fault current on A, B, C three-phase, below divides both of these case to describe in detail:
1 power distribution network adopts isolated neutral mode
When power network neutral point N is earth-free, when the phase in A, B, C three-phase, for example A goes up mutually certain some ground connection occurs, as shown in the figure.In the fault initial period, the voltage of fault phase A phase will fall rapidly, the voltage of healthy phases B phase and C phase will rise rapidly, neutral point voltage also rises rapidly, now distributed capacitance will be by earth point electric discharge over the ground rapidly over the ground for A phase feeder line, B phase and C phase feeder line over the ground distributed capacitance will, by earth point charging over the ground rapidly, form an of short duration charge and discharge process (10ms~20ms), produce larger transient state capacitance current.System will enter stable state subsequently, and power supply, by healthy phases distributed capacitance, earth point, produces a lasting stable state capacitance current.In this process, transient state capacitance current is much larger than stable state capacitance current.
The electric current of three-phase line is directly added, and just can obtain the zero-sequence current of circuit.In like manner, the voltage of three-phase line is directly added, and can obtain the residual voltage of circuit.In this process, the zero-sequence current of faulty line as shown in Figure 2.Before earth fault occurs, the zero-sequence current of circuit is very little, be approximately 0, in the time that earth fault occurs, what first occur is capacitor charge and discharge transient state process, produce larger high frequency transient capacitance current, maintain subsequently the stable state capacitance current of a main concentration of energy at power frequency (50Hz or 60Hz).
2 power distribution networks adopt neutral by arc extinction coil grounding mode
Power network neutral point N is in the time of grounding through arc, and when the phase in A, B, C three-phase, for example A goes up mutually certain some ground connection occurs, as shown in Figure 3.With earth-free similar, in the fault initial period, the voltage of fault phase A phase will fall rapidly, the voltage of healthy phases B phase and C phase will rise rapidly, neutral point voltage also rises rapidly, and now distributed capacitance will be by earth point electric discharge over the ground rapidly over the ground for A phase feeder line, and B phase and C phase feeder line over the ground distributed capacitance will be by earth point chargings over the ground rapidly, form an of short duration charge and discharge process (10ms~20ms), produce larger transient state capacitance current.Arc suppression coil L will produce an offset current subsequently, the stable state capacitance current that offset supply produces by healthy phases distributed capacitance, earth point, and system enters stable state subsequently.Adopt neutral point N through grounding through arc mode, the stable state capacitance current on faulty line will become very little, can not produce larger stable status zero-sequence current as shown in Figure 2, but the transient state capacitance current on faulty line is unaffected.
Small current neutral grounding is particularly through the singlephase earth fault of grounding through arc power distribution network, transient fault current duration is very short, stable fault currents is very little, and statistics show, the stake resistance of most singlephase earth faults is greater than 800 Ω, belongs to high resistance ground, as through branch, through meadow, through ground connection such as moist walls, at this moment transient fault electric current is also little, and the duration is very short again, only has 10~20ms.Thereby small current neutral grounding one-phase earthing failure in electric distribution network detects and location, is known as global problem, mainly contain now following several method and apparatus detecting for small current neutral grounding one-phase earthing failure in electric distribution network:
1 carries out small current line selection and device thereof in transformer station
Existing Small Electric Current Earthing And Routing Device, can select in the outlet of substation bus bar, and earth fault has occurred which bar circuit.Taking Fig. 1 and Fig. 3 as example, substation bus bar has 2 outlets, and one is faulty line, and another is faulty line, and Small Electric Current Earthing And Routing Device can be selected faulty line wherein.
Small Electric Current Earthing And Routing Device is by the residual voltage on collection substation bus bar and the zero-sequence current of each branch line, adopt the unexpected rising of residual voltage as earthing wire-selecting trigger condition, recycle stable state information and the transient information of each branch line zero-sequence current, select faulty line.According to its use information difference, can be divided into stable state line selection apparatus and transient state line selection apparatus.
The route selection of stable state line selection apparatus is according to mainly containing:
(1) the zero-sequence current amplitude maximum of faulty line;
(2) zero-sequence current phase place and the non-fault line of faulty line are anti-phase;
(3) the zero sequence reactive power of faulty line is for negative;
(4) zero sequence active power of faulty line is large;
(5) 5 subharmonic currents of faulty line are large and anti-phase with non-fault line;
(6) negative-sequence current of faulty line is large.
The route selection of transient state line selection apparatus is according to mainly containing:
(1) amplitude of the first half-wave of transient zero-sequence current in the time that phase voltage reaches maximum of faulty line and non-fault line and voltage is all different from phase place;
(2) the zero-sequence current transient information feature that adopts other disposal routes to extract as small echo, and coordinate artificial intelligence to carry out the identification of faulty line and non-fault line as neural network.
The major defect of Small Electric Current Earthing And Routing Device is:
(1) adopt the existing PT of transformer station and CT to affect route selection reliability and accuracy
Bus residual voltage as Small Electric Current Earthing And Routing Device trigger pip must obtain by the PT being connected in parallel on bus, and the ferroresonance of PT can right route selection cause larger interference.
Because special zero sequence CT volume is large, cost is high, and need the installation that has a power failure, it is not to obtain by special zero sequence CT conventionally that Small Electric Current Earthing And Routing Device obtains zero-sequence current, but is obtained with CT by the existing three-phase of transformer station or two-phase measurement.Desirable CT, does not have excitation loss electric current, the ampere turns numerically equal of primary winding and secondary coil, and once surveying electric current and secondary, to survey current phase identical and there is no phase deviation., there is exciting current in the CT of practical application, thereby the ampere turns of primary winding and secondary coil unequal, and the phase place of primary current and secondary current is not identical yet.Therefore, actual CT has angular error and the variation error in phase place conventionally, causes three-phase CT imbalance, superposeed in the zero-sequence current obtaining and had out-of-balance current, and actual zero-sequence current exists error by three-phase CT, affects route selection result.Traditional measurement CT in addition, owing to there being magnetic core, the excitation property of magnetic core is nonlinear, the electric current linearity while affecting from little electric current to large electric current; And magnetic core is when electric current is large, there will be magnetic saturation problem, can cause CT saturated, in actual applications, there is CT saturated phenomenon in Medial & Low Voltage Power Network often, now cannot obtain correct zero-sequence current and carry out route selection; There is energy storage link and hysteresis element in magnetic core, this makes CT transient characterisitics bad, bad to following of current break, is difficult to accurately catch faint transient signal.
(2) can not accurately locate the position of earth fault
Small current earthing wire-selecting can only be arranged on power distribution network bus separated time place, can only be used for selecting the branched line that occurs earth fault, and can not locate the now position of earth fault of branch line.
2 signal injection method and devices thereof
Signal injection method adopts Injection Signal source method to coordinate the continuous earth fault that fault detector can the large ground current of detection and location.The party's ratio juris is: after transformer station detects that residual voltage significantly rises and continues for some time, after zero-sequence current is greater than threshold value and continues for some time, can judge earth fault has occurred, need to drop into arc suppression coil, now inject the fault current signal of certain pattern at the neutral point of main-transformer, fault detector before earth fault all can detect this signal and provide instruction, and fault detector after earth fault all cannot detect that this signal can't move, thereby can identify the position that earth fault occurs.
As shown in Figure 4, ground signalling source is accessed controlled resistive load (middle resistance is generally more than 100 ohm) at the neutral point of substation grounding transformer between over the ground.When fault, under microcomputer control, on the neutral point of substation grounding transformer, the resistive load signal source of (no ground transformer can be connected on bus neutral point constantly) drops into automatically in short-term, thereby between transformer station and on-the-spot earth point, produces special little coded signal electric current.By the coding-control of the resistive load switching to ground signalling source, can produce the code current signal being superimposed upon on load current.The earth-fault indicator that transformer station's outlet and circuit take-off point are installed everywhere, detects auto-action instruction after this current signal, reaches the object of indication fault.
Injection Signal source method has following shortcoming:
(1) need to, in transformer station's reload signal source, change system operation mode;
(2) signal source and other equipment need extra investment and construction, need to have a power failure in work progress;
(3) earth fault more than 800 ohm for common stake resistance, cannot produce enough large coded signal electric current and make fault detector action, cannot detect high resistance earthing fault;
(4) cannot detect transient earthing fault.
3 based on networking distribution sense terminals FTU Earth Fault Detection localization method
Based on networking FTU Earth Fault Detection localization method as shown in Figure 5, the method is by installing and the supporting distribution sense terminals FTU of switch near switch on the line, three-phase current while carrying out record trouble, voltage waveform data, and data are sent to distribution automation main website analyze, the switch section at localization of faults place.
Major defect based on networking FTU Earth Fault Detection localization method is;
(1) switch need to be installed, and must there be CT and PT in switch inside, switch and FTU investment are very huge;
(2) measure the CT little current temporary state signal that defies capture, large electric current can saturated, when three superimposed generation zero sequences, because three-phase imbalance can cause larger error, high resistance ground is difficult to detection;
(3) PT has ferroresonance problem;
(4) switch and FTU are installed and need line outage construction;
(5) can only navigate to the section between switch, cannot accomplish to locate more accurately;
(6) on pole line for FTU provides power supply very difficult, affect it and install and normal work.
At present, small current neutral grounding system, particularly neutral by arc extinction coil grounding system, lack effective earth-fault detecting method and equipment, can not promptly detect earth fault, instruction earthing position.A lot of power supply departments are still using the legal position of the artificial investigation earth faults such as bracing wire method, these method automaticities are very low, performance difficulty, inefficiency, cannot meet the requirement that electric system continues to improve power supply reliability, just become and improving the quality of power supply, improving one of main difficulty of power supply reliability.In order to improve small current neutral grounding distribution network reliability, be necessary to provide a kind of method and apparatus, after small current neutral grounding power distribution network generation singlephase earth fault, no matter be low-impedance earthed system or high resistance ground, transient fault or permanent fault, can effectively detect and indicate.
Summary of the invention
The invention provides the method and apparatus that a kind of small current neutral grounding one-phase earthing failure in electric distribution network detects, indicates.
According to one aspect of the present invention, the invention discloses a kind of method that small current neutral grounding one-phase earthing failure in electric distribution network detects, indicates, it comprises:
(1) main power source from distribution feeder power taking and also power taking power-controlled, battery is as standby power supply, as long as power distribution network does not have a power failure, just can continue the power supply of the work that obtains;
(2) pick up each phase voltage by capacitive battery pressure sensor;
(3) pick up each phase current by electronic type current sensor;
(4) be with logical processing by each phase voltage signal, obtain transient voltage signal, extract amplitude, mean value, differential value, integrated value and the combination thereof of transient voltage signal, when one or more the variation in above-mentioned value exceedes threshold value, trigger doubtful earth fault and report to the police;
(5) be with logical processing by each phase current signal, obtain transient current signal, extract amplitude, mean value, differential value, integrated value and the combination thereof of transient current signal, when one or more the variation in above-mentioned value exceedes threshold value, trigger doubtful earth fault and report to the police;
(6) doubtful earth fault phase wireless synchronization triggers other phases, notifies other to upload mutually voltage, current waveform data;
(7) each adopts time-multiplexed communication mutually, guarantees real time bidirectional communication, converges three-phase voltage, current waveform data by communication;
(8) each mutually by wireless to time, realize and other phase time synchronized;
(9) according to the three-phase voltage of multiple positions, current waveform data, calculate residual voltage, zero-sequence current carries out Earth Fault Detection, after detecting earth fault, earth fault signal is issued, on fault phase, before earth fault, carry out earth fault instruction.
According to another aspect of the present invention, the invention discloses equipment---the feeder line monitoring means that a kind of small current neutral grounding one-phase earthing failure in electric distribution network detects, indicates, it comprises:
(1) feeder line clamping device, is made up of cliping line spring, line holder, blocking mechanism, damping mechanism;
(2) electricity getting device with power control, for getting the power supply of enough system works from distribution feeder;
(3) electric power controller, for carrying out power supply conversion and switching to electricity getting device and backup battery;
(4) voltage, temperature integrated transducer, for pick-up voltage signal from distribution feeder, feeder line temperature signal;
(5) electronic type current sensor, for picking up current signal from distribution feeder;
(6) wireless synchronization flip flop equipment, for trigger notice, other upload voltage, current waveform data mutually, and can assist to time;
(7) radio communication device, adopts time-multiplexed communication pattern, and outside carries out data transmission, and can be synchronously to time;
(8) treating apparatus being connected with electricity getting device, electric power controller, voltage, temperature integrated transducer, electronic type current sensor, radio communication device, wireless synchronization flip flop equipment, accident indicator, be used for controlling power taking, electrical source exchange, gather various voltage, electric current, temperature, wireless synchronization trigger pip, voltage, current signal are processed, carry out radio communication, retention time is synchronous, receives the data that a distant place sends, and carries out indicating fault;
(9) accident indicator, uses wide-angle high-brightness light emitting diode, adopts different frequency and different flash lamp mode instruction different faults.
Brief description of the drawings
Fig. 1 has shown the earth-free one-phase earthing failure in electric distribution network electric current of neutral point N.
Fig. 2 has shown that rear faulty line zero-sequence current occurs singlephase earth fault.
Fig. 3 has shown that neutral point N is through grounding through arc one-phase earthing failure in electric distribution network electric current.
Fig. 4 has shown Injection Signal source method Earth Fault Detection principle.
Fig. 5 has shown based on networking FTU earth-fault detecting method principle.
Fig. 6 A, Fig. 6 B, Fig. 6 C, Fig. 6 D have shown Method And Principle of the present invention.When Fig. 6 A has shown generation singlephase earth fault, fault phase distribution feeder monitoring means monitors short time voltage, electric current acute variation.Fig. 6 B has shown that fault phase distribution feeder monitoring means detects after doubtful earth fault, triggers other phase feeder line monitoring means by wireless synchronization.Fig. 6 C has shown that three-phase distribution net feeder line monitoring means is by wireless communication transmissions voltage, current waveform data, and the voltage of three-phase feeder line monitoring means, current waveform convergence, to communication terminal, then are uploaded to system main website.Fig. 6 D shown, the platform software of system main website is being made after Earth Fault Detection, issues the feeder line monitoring means that earth fault signal goes up before trouble spot mutually to distribution network failure and indicates.
Fig. 7 A, Fig. 7 B, Fig. 7 C have shown wireless synchronization triggering mode of the present invention.What Fig. 7 A showed is that A triggers B phase, C phase when identical; What Fig. 7 B showed is that A first triggers B phase mutually, and B triggers C phase mutually again; What Fig. 7 C showed is that A first triggers communication terminal mutually, and communication terminal triggers B phase, C phase again
Fig. 8 has shown the equipment feeder line monitoring means building according to one embodiment of the present of invention, and equipment is in feeder line clamping mechanism opening state to be installed.
Fig. 9 has shown the equipment feeder line monitoring means building according to one embodiment of the present of invention, is in feeder line clamping device and closes the state of feedback.
Figure 10 has shown the system architecture of the equipment feeder line monitoring means building according to one embodiment of the present of invention.
Figure 11 has shown the accident indicator of the equipment feeder line monitoring means building according to one embodiment of the present of invention.
Embodiment
Fig. 6 has shown Method And Principle of the present invention.
Fig. 6 A has shown, occur mutually after singlephase earth fault when small current neutral grounding distribution feeder is a certain, in earth fault transient state process, the both sides voltage and current of earth point is within a very short time, acute variation be can there is, abnormal transient voltage signal and current signal produced.Feeder line monitoring means disclosed by the invention uses capacitive battery pressure sensor, there will not be the ferroresonance problem of PT, can pick up reliably transient voltage signal.Feeder line monitoring means disclosed by the invention uses electronic type current sensor, precision to current measurement is high, the linearity good, can have very high precision to the measurement of little electric current and large electric current, and large electric current is unsaturated, transient characterisitics are good, can pick up reliably transient current signal.In small current neutral grounding one-phase earthing failure in electric distribution network transient state process, fault phase distribution feeder monitoring means is by capacitive battery pressure sensor and electronic type current sensor, can monitor transient voltage signal, transient current signal is abnormal.
Fig. 6 B shown, distribution network failure phase feeder line monitoring means detects after doubtful earth fault, triggers other phase feeder line monitoring means upload the voltage, the current waveform data that monitor by wireless synchronization.
Fig. 6 C has shown, three-phase distribution net feeder line monitoring means is by wireless communication transmissions voltage, current waveform data, by the voltage of three-phase feeder line monitoring means, current waveform convergence to communication terminal, also can be by the voltage of two-phase feeder line monitoring means, current waveform convergence to a three-phase feeder line monitoring means phase wherein, by communication terminal or feeder line monitoring means by voltage, current waveform data upload the platform software to system main website.
Fig. 6 D has shown, the platform software of system main website is after obtaining the three-phase distribution net feeder line monitoring means voltage of multiple positions, current waveform data, the residual voltage of multiple positions that can calculate, zero-sequence current waveform, and according to residual voltage, zero-sequence current waveform character, make Earth Fault Detection, issue the feeder line monitoring means that earth fault signal goes up before trouble spot mutually to distribution network failure and indicate.
When a certain phase feeder line monitoring means monitors after doubtful earth fault, need to notify rapidly other two-phase to upload voltage, current waveform data, by three-phase voltage, current waveform data, obtain residual voltage and zero sequence current signal, carry out further earth fault judgement.The wireless synchronization flip flop equipment of the feeder line monitoring means that the present invention proposes, can use any or combination of infrared ray, sound, ultrasound wave, magnetic field, elect magnetic field as trigger pip, is sent to other two-phase.Feeder line monitoring means wireless synchronization flip flop equipment can also receive wireless synchronization trigger pip simultaneously.Wireless synchronization trigger mode has several as follows:
(1) as shown in Figure 7 A, suppose that A phase feeder line monitoring means monitors doubtful earth fault, A phase feeder line monitoring means is just by wireless synchronization flip flop equipment, and wireless synchronization triggers B phase feeder line monitoring means and C phase feeder line monitoring means;
(2) as shown in Figure 7 B, suppose that A phase feeder line monitoring means monitors doubtful earth fault, A phase feeder line monitoring means is just by wireless synchronization flip flop equipment, and wireless synchronization triggers B phase feeder line monitoring means, subsequently B phase feeder line monitoring means wireless synchronization triggering C phase feeder line monitoring means again;
(3) as shown in Fig. 7 C, suppose that A phase feeder line monitoring means monitors doubtful earth fault, A phase feeder line monitoring means is just by wireless synchronization flip flop equipment, and wireless synchronization triggers communication terminal, and communication terminal again wireless synchronization triggers B phase feeder line monitoring means and C phase feeder line monitoring means.
Fig. 8 has shown the equipment 100 building according to one embodiment of the present of invention, i.e. feeder line monitoring means, and equipment 100 is in feeder line clamping mechanism opening state to be installed.The housing of equipment 100 is made up of upper arm 101, main body 104, transparent lower house 105.Upper arm 101 is made up of two halves 102 and 103, and a part for electronic type current sensor is housed in 102, and a part for electricity getting device is housed in 103.The electricity getting device remainder of equipment, electric power controller, electronic type current sensor remainder, wireless synchronization flip flop equipment, radio communication device, treating apparatus, accident indicator are positioned at main body 104, and the light that the indication LED of accident indicator is sent emits by transparent lower house 105.All devices will all be potted in main body 104 with casting glue.
The electricity getting device core of equipment 100 is one to have the magnetic element of closed magnetic circuit, as annular or other have the magnetic element of similar closed magnetic circuit, this closed magnetic circuit surrounds distribution feeder 106, this magnetic element is cut into two parts, a part is positioned at upper arm 103, and a part is positioned at main body 104.On magnetic element, be wound with the coil that power taking is used, this coil connects power control circuit.In order to allow electricity getting device just can get abundant power supply when current flowing is very little on distribution feeder 106, two parts magnetic element passes through blocking device, realize magnetic circuit tight close, blocking device is made up of the spring of pressing that is positioned at case spring, the damper of upper arm axle 116 and is positioned at the magnetic element of upper arm 103, case spring makes upper arm and main body close contact, damper can slow down the impulsive force of upper arm in locking process, and the magnetic element in the magnetic element in upper arm 103 and main body 104 is again by realizing close contact by pressing spring.
Traditional electricity getting device, if when the electric current flowing through on distribution feeder 106 hour, can be got the power supply that enough equipment 100 works, when the electric current flowing through on distribution feeder 106 is so very large, magnetic element will be saturated, and get less than electricity; If when the electric current flowing through on distribution feeder 106 is very large, magnetic element is unsaturated, the electric current flowing through on distribution feeder 106 so hour, just can not be got the power supply that enough equipment 100 is worked.The present invention can make electric current that magnetic element flows through on distribution feeder 106 hour by power control circuit, can get the power supply that enough equipment 100 is done, in the time that the electric current flowing through on distribution feeder 106 is very large, power control circuit can make magnetic element unsaturated, still can get the power supply that enough equipment 100 is worked.
The power supply that equipment 100 electric power controllers obtain electricity getting device, convert system works power supply to, when in the situation that distribution feeder has a power failure and electricity getting device power supply cannot be powered, automatically switch to backup battery power supply, when in the situation that electricity getting device power supply can be powered, automatically switch to electricity getting device power supply.
Equipment 100 is by voltage, temperature integrated transducer 117 pick-up voltages and temperature signal, sensor 117 is made up of stainless steel, with distribution feeder close contact, there is good conduction, thermal conduction characteristic, can pick up the voltage signal on feeder line, also the heat on feeder line can be conducted to thermal sensing element simultaneously.
Equipment 100 picks up current signal by electronic type current sensor, electronic type current sensor can be Current Transmit, it can be current transformer, also can be Wound-rotor type Luo-coil, also can be the board-like Luo-coil of printed circuit, the part that electronic type current sensor is measured magnetic circuit is positioned at upper arm 102, and another part is positioned at main body 104.
Equipment 100, by feeder line clamping device, is installed on feeder line, can, in the situation that using Luo-coil electronic type current sensor, allow feeder line in Luo-coil magnetic circuit center simultaneously.The feeder line clamping device of equipment 100 is by the spring pin 111,112,113,114 of 107,108,109,110,4 fixed card wire springs of 4 cliping line springs, and line holder 115 forms.
Fig. 9 has shown the equipment 100 feeder line monitoring means that build according to one embodiment of the present of invention, is in the state of feeder line clamping device locking.Under blocking, feeder line accommodates the staggered feeder line 106 of holding tightly of 4 springs 107,108,109,110 of device, by in fixing feeder line 106 online holder 115, two parts magnetic element of electricity getting device is realized and being fitted tightly, and feeder line 106 is positioned at the center of electronic type current sensor closed magnetic circuit.Voltage, temperature integrated transducer 117 and distribution feeder 106 have been realized and having been fitted tightly.
The system architecture of the equipment 100 feeder line monitoring means that build according to one embodiment of the present of invention as shown in figure 10.On power taking magnetic element 201, be wound with electricity taking coil 202, feeder line 212 is positioned at magnetic element magnetic circuit center, electricity taking coil 202 access power control device 203, and the power control circuit 203 of battery 204 and electricity getting device accesses electric power controller 205.Electric power controller 205 converts the required power supply of equipment 100 to power control circuit 203 out-put supplies of electricity getting device and battery 204, switches between power control circuit 203 and battery 204 simultaneously.
Treating apparatus 208 gathers the voltage signal that voltage, temperature integrated transducer 206 pick up, voltage signal is with to logical processing, obtain transient voltage signal, extract amplitude, mean value, differential value, integrated value and the combination thereof of transient voltage signal, when one or more the variation in above-mentioned value exceedes threshold value, trigger doubtful earth fault and report to the police.
Treating apparatus 208 gathers the current signal that electronic type current sensor 207 picks up, current signal is with to logical processing, obtain transient current signal, extract amplitude, mean value, differential value, integrated value and the combination thereof of transient current signal, when one or more the variation in above-mentioned value exceedes threshold value, trigger doubtful earth fault and report to the police.
Treating apparatus 208, after triggering doubtful earth fault warning, triggers the feeder line monitoring means equipment 100 of other phases immediately by wireless synchronization flip flop equipment 210.
Treating apparatus 208 is by radio communication device 209 and outsidely adopt time-multiplexed mode to carry out radio communication, and carry out synchronously to time, ensure that 100 retention times of feeder line monitoring means equipment of arbitrary phase equipment 100 and other phases are synchronous.
The accident indicator of the equipment 100 feeder line monitoring means that build according to one embodiment of the present of invention as shown in figure 11.Accident indicator, adopts 3 wide-angle high-brightness light emitting diodes, 301,302,303,120 degree uniformly-spaced to arrange, is receiving after earth fault signal, adopts different frequency and different flicker pattern to indicate different earth fault.
The above; be only the specific embodiment of the present invention, but protection scope of the present invention is not limited to this, any be familiar with those skilled in the art the present invention disclose technical scope in; can expect easily changing or replacing, within all should being encompassed in protection scope of the present invention.Therefore, protection scope of the present invention should described be as the criterion with the protection domain of claim.

Claims (10)

1. according to one aspect of the present invention, the invention discloses a kind of method that small current neutral grounding one-phase earthing failure in electric distribution network detects, indicates, it comprises:
(1) main power source from distribution feeder power taking and also power taking power-controlled, battery is as standby power supply, as long as power distribution network does not have a power failure, just can continue the power supply of the work that obtains;
(2) pick up each phase voltage by capacitive battery pressure sensor;
(3) pick up each phase current by electronic type current sensor;
(4) be with logical processing by each phase voltage signal, obtain transient voltage signal, extract amplitude, mean value, differential value, integrated value and the combination thereof of transient voltage signal, when one or more the variation in above-mentioned value exceedes threshold value, trigger doubtful earth fault and report to the police;
(5) be with logical processing by each phase current signal, obtain transient current signal, extract amplitude, mean value, differential value, integrated value and the combination thereof of transient current signal, when one or more the variation in above-mentioned value exceedes threshold value, trigger doubtful earth fault and report to the police;
(6) doubtful earth fault phase wireless synchronization triggers other phases, notifies other to upload mutually voltage, current waveform data;
(7) each adopts time-multiplexed communication mutually, guarantees real time bidirectional communication, converges three-phase voltage, current waveform data by communication;
(8) each mutually by wireless to time, realize and other phase time synchronized;
(9) according to the three-phase voltage of multiple positions, current waveform data, calculate residual voltage, zero-sequence current carries out Earth Fault Detection, after detecting earth fault, earth fault signal is issued, on fault phase, before earth fault, carry out earth fault instruction.
2. according to another side of the present invention, the invention discloses equipment---the feeder line monitoring means that a kind of small current neutral grounding one-phase earthing failure in electric distribution network detects, indicates, it comprises:
(1) feeder line clamping device, is made up of cliping line spring, line holder, blocking mechanism, damping mechanism;
(2) electricity getting device with power control, for getting the power supply of enough system works from distribution feeder;
(3) electric power controller, for carrying out power supply conversion and switching to electricity getting device and backup battery;
(4) voltage, temperature integrated transducer, for pick-up voltage signal from distribution feeder, feeder line temperature signal;
(5) electronic type current sensor, for picking up current signal from distribution feeder;
(6) wireless synchronization flip flop equipment, for trigger notice, other upload voltage, current waveform data mutually, and can assist to time;
(7) radio communication device, adopts time-multiplexed communication pattern, and outside carries out data transmission, and can be synchronously to time;
(8) treating apparatus being connected with electricity getting device, electric power controller, voltage, temperature integrated transducer, electronic type current sensor, radio communication device, wireless synchronization flip flop equipment, accident indicator, be used for controlling power taking, electrical source exchange, gather various voltage, electric current, temperature, wireless synchronization trigger pip, voltage, current signal are processed, carried out radio communication, the retention time is synchronous, receive the data that a distant place sends, carry out indicating fault;
(9) accident indicator, uses wide-angle high-brightness light emitting diode, adopts different frequency and different flash lamp mode instruction different faults.
3. equipment according to claim 2, it is characterized in that: described equipment body is made up of three parts, the first half, main body, transparent shell, the first half and main body are surrounded the feeder line that needs clamping, in main body by the feeder line clamping device being formed by spring, line holder, blocking mechanism, feeder clip is held between line holder and spring, can regulate the optional position of feeder line between the first half and main body by line holder, the first half, by blocking mechanism and main body tight closure, can have damper slow down the speed of locking process and reduce impulsive force.
4. equipment according to claim 2, it is characterized in that: described equipment power supply mainly depends on from feeder line electricity getting device, battery is as backup, described feeder line electricity getting device core is a magnetisable material with closed magnetic circuit, in two, lay respectively in the first half and main body of equipment, realize the tight closure of magnetic circuit by blocking mechanism, blocking device is by the case spring or the other types elastic mechanism that are positioned at first half split axle, damper and be positioned at the first half magnetic element by pressing spring or other types elastic mechanism composition, the control of electricity getting device band power, can control from feeder line power taking power, while guaranteeing feeder line stream too little current, just can get the power of enough work, can be unsaturated when feeder line stream super-high-current or can continue power taking.
5. equipment according to claim 2, it is characterized in that: described equipment uses voltage, temperature integrated transducer (voltage segment is capacitance type sensor) pick-up voltage signal, electronic type current sensor picks up current signal, electronic type current sensor can be current transformer, also can be Wound-rotor type Luo-coil, also can be the board-like Luo-coil of printed circuit, electronic type current sensor be divided into two parts, lays respectively in the first half and main body of equipment.
6. equipment according to claim 2, it is characterized in that: described equipment is with logical processing to the voltage signal picking up, obtain transient voltage signal, extract band logical amplitude, mean value, differential value, integrated value and the combination thereof of voltage signal afterwards, when one or more the variation in above-mentioned value exceedes threshold value, trigger doubtful earth fault and report to the police.
7. equipment according to claim 2, it is characterized in that: described equipment is with logical processing to the current signal picking up, obtain transient current signal, extract amplitude, mean value, differential value, integrated value and the combination thereof of transient current signal, when one or more the variation in above-mentioned value exceedes threshold value, trigger doubtful earth fault and report to the police.
8. equipment according to claim 2, it is characterized in that: described equipment is after producing doubtful earth fault warning, trigger other two-phase by wireless synchronization flip flop equipment, described wireless synchronization flip flop equipment can use infrared ray, sound, ultrasound wave, magnetic field, electromagnetic field is as trigger pip, directly be sent to all the other two-phases, or be first sent to an adjacent phase, transferred to the other phase in three-phase by adjacent again, or be first sent to adjacent radio communication terminal, be sent to all the other two-phases in three-phase by communication terminal device again, notify all the other two-phases to upload voltage, current waveform data, be used for calculating residual voltage and zero sequence current signal detection of ground faults, simultaneously wireless synchronization flip flop equipment can also carry out carrying out between different described equipment synchronously to time.
9. equipment according to claim 2, it is characterized in that: described equipment carries out data transmission by radio communication device and the external unit of time division multiplex mode of operation, described equipment is by time division multiplex fault mode, can between different described equipment, carry out synchronously to time.
10. equipment according to claim 2, it is characterized in that: described equipment is to indicate after must arriving the earth fault confirmation signal transmitting in a distant place again, what the accident indicator that described equipment adopts used is wide-angle high-brightness light emitting diode, can ensure the omnirange instruction that maximum hemispherical area 360 spends, the accident indicator of described equipment is used to refer to dissimilar fault by different number of diodes objects combine, glimmer interval and flicker frequency.
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FIEP14772927.1T FI2985613T3 (en) 2013-03-29 2014-03-27 Method and system for detecting and locating single-phase ground fault on low current grounded power-distribution network
EP14772927.1A EP2985613B1 (en) 2013-03-29 2014-03-27 Method and system for detecting and locating single-phase ground fault on low current grounded power-distribution network
RS20220345A RS63098B1 (en) 2013-03-29 2014-03-27 Method and system for detecting and locating single-phase ground fault on low current grounded power-distribution network
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