CN104065056A - Process control method of 10 kV power grid ground fault - Google Patents
Process control method of 10 kV power grid ground fault Download PDFInfo
- Publication number
- CN104065056A CN104065056A CN201410312600.1A CN201410312600A CN104065056A CN 104065056 A CN104065056 A CN 104065056A CN 201410312600 A CN201410312600 A CN 201410312600A CN 104065056 A CN104065056 A CN 104065056A
- Authority
- CN
- China
- Prior art keywords
- electrical network
- earth fault
- time
- suppression coil
- arc suppression
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
A process control method of a 10 kV power grid ground fault disclosed by the present invention comprises the steps of when a ground fault occurs in a 10 kV power grid, using a controller to control a grounding transformer to access an arc suppression coil to compensate the 10 kV power grid, and using the controller to determine whether the ground fault is removed within limiting time; if yes, determining the ground fault as the instantaneous ground fault, and using the controller to control the arc suppression coil to stop compensation when the grounding is ended; if no, determining the ground fault as the permanent fault, and using the controller to control a high voltage contactor in a closed state to control the grounding transformer to access a small resistor, wherein one end of the small resistor is grounded, and the other end is connected with the high voltage contactor; using the controller to control the arc suppression coil to stop compensation when the permanent fault grounding is ended, and control the high contactor in a disconnection state to disconnect the small resistor. The process control method of the 10 kV power grid ground fault provided by the present invention has the advantages of automatic switching, and high safety and reliability.
Description
Technical field
The present invention relates to technical field of power systems, relate in particular to a kind of course control method for use of 10kV electrical network earth fault.
Background technology
Along with the development of electrical network, the capacity of electrical network is increasing, more and more higher to the reliability requirement of electrical network, intellectuality is proposed to requirements at the higher level.Power distribution network as electric power system send out, defeated, join and electricity consumption in a link, play a part to form a connecting link, its importance more and more comes into one's own, and the processing of distribution net work earthing fault be always puzzlement vast operation of power networks personnel significant problem.Traditional earthing mode exposes increasing drawback, in the urgent need to seek a kind of more perfect novel grounded mode on existing basis, to adapt to the development need of distribution automation, solves the control ability of electrical network on earth fault is processed.
Electric power system can be divided into heavy current grounding system (comprising direct ground connection, reactance grounded and low-impedance earthed system etc.), small current neutral grounding system (comprising high resistance ground, grounding through arc and earth-free etc.) by grounding mode.For guaranteeing accurate isolated fault circuit, a lot of cities all start to adopt the operational mode of Neutral Point Through Low Resistance.But due to low resistance grounding mode, for earth fault, tripping operation is non-selectivity, makes any instantaneity earth fault all can cause line tripping.Although recovered power transmission by these instantaneity earth faults of reclosing mode, also caused thus user's unnecessary electricity consumption is interrupted and repeatedly percussion action of transformer station's line switching.The trip-out rate of the distribution network system of application low resistance grounding mode is high, power supply reliability is poor, can not meet the demand of user to power supply reliability increasingly stringent.
In recent years, various places electric company has progressively built distribution automation system, plays a positive role to improving power distribution network operation and management level.The quick location isolation that realizes fault is a Core Feature of distribution automation, but in the system of existing grounding through arc, in the time there is earth fault, although obtained the compensation of arc suppression coil, but automatic intelligent terminal is difficult to accurately locate fault, thereby cannot realize the function of its automatic separating fault, therefore the effectiveness of distribution automation is had a greatly reduced quality.
In the process of construction of urban and rural power grids, China's distribution neutral ground has mainly adopted resonance grounding (grounding through arc) and low resistance grounding pattern, wherein grounding through arc mode can be eliminated transient single-phase earth fault automatically, there is the tripping operation of minimizing number of times, reduce earth fault current, but it is low that low resistance grounding pattern has overvoltage level, the advantage such as can move in time.But along with being widely used of the application popularization cable of distribution automation, single ground connection pattern will face following serious problems:
1. can not automatically excise non-transient single phase ground fault, whole distribution system must be born the power-frequency overvoltage (line voltage) of long period, therefore requires high to the insulation level of equipment;
2. can not automatic identification non-transient earth fault and instantaneity earth fault, and differentiated treatment in addition;
3. the long-time existence of earth fault, is unfavorable for equipment and personal safety, has potential safety hazard;
4. cannot cooperation with distribution automation system.
Data statistics shows, taking cable as main electrical network, non-transient fault (permanent fault) and phase fault are higher than the electrical network taking overhead wire as leading.Tracing it to its cause is that cable body fault is less, and large multiple faults occurs in cable joint place, and permanent fault and phase fault are increased, and might not be permanent fault or phase fault but ground connection occurs cable system.In 10kV electrical network, cable proportion increases, and which kind of earthing mode no matter neutral point adopt, and except overvoltage is considered, also should consider the problem such as short circuit current and relaying protection.
Summary of the invention
Technical problem to be solved by this invention is, a kind of course control method for use of 10kV electrical network earth fault is provided, by the more perfect reliable earthing mode of one, to meet along with power distribution network capacity is increasing, the requirement more and more higher to the reliability of power distribution network, with in time, process electric network fault discriminatively, ensure the safety of electrical network to the person and equipment.
For solving above technical problem, the invention provides a kind of course control method for use of 10kV electrical network earth fault, comprising:
Set up into earth fault treatment system by grounding transformer with arc suppression coil, high voltage connector, small resistor and controller; Described grounding transformer is connected with 10kV electrical network bus;
In the time of described 10kV electrical network generation earth fault, grounding transformer accesses described arc suppression coil so that 10kV electrical network is compensated described in described controller control;
Described controller judges whether described earth fault is removed in limiting time; If so, judge that described earth fault is as transient earthing fault, and described in the time that ground connection is finished described in controller control arc suppression coil exit compensation; If not, judge that described earth fault is as permanent fault, and described controller is that closure state accesses described small resistor to control described grounding transformer by controlling described high voltage connector; One end ground connection of described small resistor, the other end is connected with described high voltage connector;
Described controller finishes arc suppression coil described in time control system permanent fault ground connection and exits compensation, and is that off-state is to exit described small resistor by controlling described high voltage connector.
Further, describedly judge that whether described earth fault is removed in limiting time, is specially:
Detect the time that described arc suppression coil compensates 10kV electrical network;
Make-up time by described arc suppression coil to electrical network and described limiting time compare; In the time that the time that described arc suppression coil compensates 10kV electrical network exceedes described limiting time, described controller judges that described earth fault do not remove in limiting time; Otherwise described controller judges that described earth fault removes.
In the attainable mode of one, grounding transformer accesses described arc suppression coil so that 10kV electrical network is compensated described in described controller control, comprising:
Described controller calculates the inductive current that needs compensation according to the current value of the electrical network electric capacity of having measured;
Described in described controller control, arc suppression coil continues output and the described current signal that needs the inductive current equivalent compensating, and records the time that described arc suppression coil compensates 10kV electrical network.
Further, described arc suppression coil comprises a controlled reactor in short-term,, described in described controller control, grounding transformer accesses described arc suppression coil so that 10kV electrical network is compensated, and also comprises: described controller carries out real-time tracking monitoring to 10kV electrical network in real time by described controlled reactor in short-term;
In the time that power-to-ground capacitance changes, described arc suppression coil detects the variable quantity that the neutral point voltage of described grounding transformer occurs, and measures the current capacitance to earth of electrical network;
According to the variable quantity of described neutral point voltage and the current capacitance to earth of electrical network, described arc suppression coil needs the inductive current of compensation to electrical network output, to eliminate instantaneity earth fault.
Preferably, described controlled reactor is in short-term high short-circuit impedance transformer;
Described high short-circuit impedance transformer comprises winding and secondary winding; Wherein, a described winding is as on Working winding access 10kV neutral point of electric network; Described secondary winding is the circuit being made up of the silicon controlled rectifier of two reverse parallel connections, and is connected with described controller as controlling winding;
Described controller changes between 0 to 180 degree by the angle of flow of controlling described silicon controlled rectifier, to adjust the equiva lent impedance of described silicon controlled rectifier, thereby regulates the offset current of described arc suppression coil to electrical network.
Preferably, described high voltage connector is made up of two vacuum contactor parallel connections; , in the time that described earth fault is permanent fault, it is closure state that described controller adopts alternating current-direct current two-way power supply to control respectively two described vacuum contactors, and described small resistor is accessed to described grounding transformer; And in the time that described permanent fault is eliminated, two vacuum contactors described in described controller control are off-state, cut off the isolation of described small resistor to earth fault.
The course control method for use of 10kV electrical network earth fault provided by the invention, realize the synergy of arc suppression coil and small resistor, and the automatic switchover of two kinds of earthing modes of application Based Intelligent Control logic realization, ground connection is continued to duration and judge, distinguish transient earthing fault and permanent earth fault.Take different counter-measures for these two kinds of earth faults, both ensured the accurately isolation rapidly to permanent earth fault, the problem of avoiding system power frequency overvoltage long-term existence and cause accident further to expand, can carry out fine compensation to instantaneity earth fault again dies away it, avoid repeatedly tripping and affect user's work, having improved the safety and reliability of earth fault processing procedure.
Brief description of the drawings
Fig. 1 is the structural representation of a kind of 10kV electrical network earth fault treatment system provided by the invention;
Fig. 2 is the schematic flow sheet of an embodiment of the course control method for use of the 10kV electrical network earth fault of the realization of the system based on Fig. 1 provided by the invention;
Fig. 3 is a kind of structural representation that can implementation of the transformer of controllable reactance in short-term provided by the invention;
Fig. 4 is circuit theory diagrams and the equivalent circuit diagram thereof of high short-circuit impedance transformer provided by the invention; Wherein, Fig. 4 (a) is the secondary winding O2-X2 of high short-circuit impedance transformer and the connecting circuit figure of controllable silicon SCR, and Fig. 4 (b) is the equivalent circuit diagram of high short-circuit impedance transformer;
Fig. 5 is the earth fault handling process schematic diagram of the course control method for use of the 10kV electrical network earth fault that provides of Fig. 2 of the present invention.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described.
Referring to Fig. 1, it is the structural representation of a kind of 10kV provided by the invention (kilovolt) electrical network earth fault treatment system.
In the present embodiment, set up into earth fault treatment system by grounding transformer 101 with arc suppression coil 102, high voltage connector 103, small resistor 104 and controller 105, and described grounding transformer 101 is connected with 10kV electrical network bus.Particularly, grounding transformer 101 is connected with 10kV electrical network by 1KG electric brake, is connected with arc suppression coil 102 and high voltage connector 103 by isolation switch.Be arranged on CT (Current Transformer, the current transformer) monitoring flow of small resistor 104 lead-out wire positions through the resistance of electric current and the resistance of resistance.
Described grounding transformer 101 produces system neutral PT, and the 10kV bus of one end of described grounding transformer 101 connection power distribution network, and the other end is connected with described high voltage connector 103 and described arc suppression coil 102; Described small resistor 104 one end ground connection, and by the switching over of described high voltage connector 103, be electrically connected with described grounding transformer 101 and described arc suppression coil 102.
Described controller 105 is installed in master-control room, and communicates to connect with described arc suppression coil 102, to control the parameter being produced with measuring equipment.
Referring to Fig. 2, it is the schematic flow sheet of an embodiment of the course control method for use of the 10kV electrical network earth fault of the realization of the system based on Fig. 1 provided by the invention.
In the present embodiment, grounding transformer 101 is connected with 10kV electrical network bus, and described grounding transformer 101 is by realizing the control to 10kV electrical network earth fault with arc suppression coil 102, controller 105, high voltage connector 103 and small resistor 104.When concrete enforcement, the course control method for use of described 10kV electrical network earth fault comprises:
Step S201: in the time of described 10kV electrical network generation earth fault, described controller 105 is controlled described grounding transformer 101 and accessed described arc suppression coil 102 so that 10kV electrical network is compensated;
Step S202: described controller 105 judges whether described earth fault is removed in limiting time; If so, judge that described earth fault is as transient earthing fault, and perform step S205; If not, judge that described earth fault is as permanent fault, and execution step S203;
Step S203: described controller 105 accesses described small resistor 104 for closure state to control described grounding transformer 101 by controlling described high voltage connector 103; One end ground connection of described small resistor 104, the other end is connected with described high voltage connector 103; And perform step S204;
Step S204: described controller 105 is that off-state is to exit described small resistor 104 by controlling described high voltage connector 103 in the time that permanent fault ground connection is finished; And perform step S205;
Step S205: described in the time that ground connection is finished, controller 105 is controlled described arc suppression coil 102 and exited compensation.
When concrete enforcement, for 10kV power distribution network, the winding in grounding transformer 101 is Δ connection (triangle connection), and grounding transformer 101 produces neutral point PT, wherein, the point that the absolute value of voltage in the winding of transformer and between outside each terminals equates is neutral point.For reducing zero sequence impedance, grounding transformer 101 preferably adopts Z-shaped wiring, and as required can be with suitable secondary capacity.
Further, described arc suppression coil 102 comprises a controllable reactance transformer in short-term, is called for short controlled reactor., described step S201 also comprises: described controller 105 carries out real-time tracking monitoring to 10kV electrical network in real time by described controlled reactor in short-term;
In the time that power-to-ground capacitance changes, described arc suppression coil 102 detects the variable quantity that the neutral point voltage of described grounding transformer 101 occurs, and measures the current capacitance to earth of electrical network;
According to the variable quantity of described neutral point PT voltage and the current capacitance to earth of electrical network, described arc suppression coil 102 needs the inductive current of compensation to electrical network output, to eliminate instantaneity earth fault.
In the present embodiment, controlled reactor adopts intelligent rapid arc extinction core technology, and short-circuit impedance can reach 100%.
As shown in Figure 3, be a kind of structural representation that can implementation of the transformer of controllable reactance in short-term provided by the invention.
In the present embodiment, described controlled reactor in short-term (controlled reactor) can be preferably high short-circuit impedance transformer, and described arc suppression coil 102 is high short-circuit impedance pressure swing type Controllable Arc-Suppression Coil System.By the controlled reactor in arc suppression coil 102 is controlled in real time, can realize the arc suppression coil 102 in the present embodiment adjustable continuously, and have adjustable range greatly, exit rapidly at any time, without advantages such as damping resistances, make 10kV electrical network earth fault treatment system become controllable type grounding through resistance integral system.Controlled reactor is because its comprehensive adjustment performance is better and the high advantage of reliability makes its scope of application more extensive.
Particularly, described high short-circuit impedance transformer comprises winding O1-X1 and secondary winding O2-X2; Wherein, a described winding O1-X1 is as on Working winding access 10kV neutral point of electric network; Described secondary winding O2-X2 is by the controllable silicon of two reverse parallel connections (Silicon Controlled Rectifier, be called for short SCR) circuit of rectifier cell composition, and be connected with described controller 105 as controlling winding (Control Winding, CW); In the present embodiment, the current i PT of the neutral point PT access that the winding A-X of arc suppression coil 102 and grounding transformer 101 produce, thereby the inductive current of change arc suppression coil 102.When concrete enforcement, high short-circuit impedance transformer also comprises choke L1 and capacitor C1, choke L2 and capacitor C2, wherein, choke L1 and capacitor C1 composition series circuit, choke L2 and capacitor C2 composition series circuit, above two series circuits are connected in parallel on the two ends of a winding O1-X1; Controllable silicon SCR rectifier cell is connected to the two ends of secondary winding O2-X2.
In the present embodiment, described controller 105 changes between 0 to 180 degree by the angle of flow of controlling described silicon controlled rectifier, to adjust the equiva lent impedance of described silicon controlled rectifier, thereby regulates the offset current of described arc suppression coil 102 to electrical network.
Referring to Fig. 4, be circuit theory diagrams and the equivalent circuit diagram thereof of high short-circuit impedance transformer provided by the invention.Wherein, Fig. 4 (a) is the secondary winding O2-X2 of high short-circuit impedance transformer and the connecting circuit figure of controllable silicon SCR, and Fig. 4 (b) is the equivalent circuit diagram of high short-circuit impedance transformer.
Particularly, arc suppression coil A-X and secondary winding O2-X2 are equivalent to inductive impedance Xk, and controllable silicon SCR rectifier cell is equivalent to the adjustable resistance Z of resistance between 0～+ ∞
sCR.Change between 0 to 180 degree by the angle of flow that regulates controllable silicon SRC, make the equiva lent impedance Z of controllable silicon SRC
sCRbetween infinity to zero, change the equiva lent impedance Z at Working winding two ends (A-X two ends)
eqthe just short-circuit impedance Z to transformer in infinity
sCbetween (being inductive impedance Xk), change, the offset current of output just can regulate to obtaining continuous stepless between rated value zero.
Wherein,
for the current vector value of neutral point inflow arc suppression coil,
with
be respectively the vector value of neutral point current and neutral point voltage.
System keeps track compensation monitoring principle is: system real-time tracking power distribution network, when power-to-ground capacitance changes, be that arc suppression coil 102 detects that, when grounding transformer 101 neutral point voltages have the variation of Δ U (Δ U<1V), system is measured power distribution network capacitance to earth at that time within the short time (as 1 second).After measurement completes, system can be passed through screen display capacitance current, represents that earth point is by the capacitance current flowing through in the time there is Single Phase Metal ground connection.
Measure based on power distribution network zero sequence loop, utilize the neutral point current of change inductance front and back, the vector of neutral point voltage to change, its computing formula is as follows:
Wherein,
with
be respectively two groups of neutral point current in different induction situation and the vector value of neutral point voltage.
The present embodiment adopts high short-circuit impedance pressure swing type Controllable Arc-Suppression Coil System to process and have advantages of following uniqueness 10kV electric network fault:
One, because adopting short-circuit impedance instead of excitation impedance as working impedance, thereby arc suppression coil 102 voltage-current characteristics can ensure to keep the splendid linearity in the 0-110% range of nominal tension;
Its two, because adopting SCR control, thereby arc suppression coil 102 response speeds are exceedingly fast, and output current can regulate by continuous stepless between 0-100% rated current; Adopt with mode control, while normally operation, electrical network is away from resonance point, without the damping resistance easily having problems;
Its three, compared with traditional arc suppression coil etc., the arc suppression coil 102 that the present embodiment provides simple in structure, noise is little, is not with any rotation or transmission mechanism, without loaded switch and contactor.
When concrete enforcement, the system of employing Fig. 1 is put into earth fault is processed, conventionally need to be according to the type of the lasting time failure judgement of earth fault.But in the time just fault being detected, as shown in Figure 5, first it is judged to instantaneity earth fault in advance and processes, because this instantaneity earth fault is in the time that control arc suppression coil 102 compensates, according to operating experience, the make-up time is generally no more than 10 seconds; Therefore, if earth fault in 10 seconds, after arc suppression coil 102 compensation, earth fault is died away, and can judge that this earth fault is transient fault; Otherwise this earth fault is judged to be permanent earth fault.Now, need automatically to control and add small resistor 104 to process earth fault.That is, to permanent earth fault, early investment Controllable Arc-Suppression Coil System 102 compensates, and ground connection continuing dropped into small resistor 104 after exceeding setting time automatically; By the switch protection of high voltage connector 103, excision faulty line; After faulty line excision, fault disappears, and arc suppression coil 102 exits compensation automatically, and the high voltage connector 103 of small resistor 104 disconnects automatically, exits small resistor 104.
Therefore, in the present embodiment, described step S202 judges that whether described earth fault is removed in limiting time, is specially:
Detect the time that described arc suppression coil 102 compensates 10kV electrical network; Make-up time by described arc suppression coil to electrical network and described limiting time compare.In the time that the time that described arc suppression coil 102 compensates 10kV electrical network exceedes described limiting time, controller 105 judges that described earth fault do not remove in limiting time; Otherwise controller 105 judges that described earth fault removes.
In the present embodiment, in the time dropping into small resistor 104, need to judge the timing input of small resistor 104.Particularly, in ground connection process, drop into time delay if ground connection arrives small resistor time of delay, close controllable silicon SCR and stop arc suppression coil 102 and compensate, and control closed high contactor 103 and drop into small resistor 104.Send after the order that drops into small resistor 104 at controller 105, the auxiliary node of two high voltage connectors of monitoring, as still do not receive auxiliary node displacement after sending input order a period of time (as 1 second), be judged as high voltage connector fault; In like manner, do not receive that auxiliary node displacement also can be judged as high voltage connector fault sending after disconnecting small resistor 104 order.
When concrete enforcement, when the earth fault that needs judgement to drop into small resistor 104 finishes.Particularly, ground connection end judges that flow process is in two kinds of situation:
Ground connection is finished judgement (1): judge according to the duration of ground connection;
Ground connection is finished judgement (2): drop into after small resistor 104, only need to follow the tracks of the variation of neutral point PT voltage magnitude, for example, in the time that being less than set point (300V), double calculating neutral point PT voltage is ground connection end, control high voltage connector 103 and disconnect small resistor 104, return to normal operating condition.
In one can implementation, described step S201 also comprises:
Controller 105 calculates the inductive current that needs compensation according to the electric network capacitance and current value of having measured, control described arc suppression coil 102 and continue output and the described current signal that needs the inductive current equivalent compensating, and record the time that described arc suppression coil 102 compensates 10kV electrical network.
The feature of the controlled reactor that the present embodiment provides is to allow running time very short under its design rated current, approximately tens of seconds, this design feature has determined its volume greatly to be reduced, and can design with the compact integrated cabinet of secondary accessory, effectively saves transformer station's floor space.
In preferred implementation, described high short-circuit impedance transformer is arranged in the on-site control that adopts compact integrated cabinet design, and in described on-site control, is also equipped with high-power silicon controlled rectifier and filter.In addition, the linear quadratic control device of controlled reactor is also arranged on reactance transformer cabinet, has avoided the cable line of long distance to lay, and has simplified product structure and also improved reliability and the antijamming capability of product simultaneously.
The operation principle of the course control method for use of the 10kV electrical network earth fault that the present embodiment provides is:
In the time of power distribution network generation earth fault, equipment calculates the inductive current that needs compensation according to the electric network capacitance and current value of having measured by controller 105, then controls controlled reactor output offset current.After general instantaneity earth fault is compensated by inductive current, arc extinction earth fault is eliminated recovery normal condition automatically, thereby has avoided occurring in low resistance grounding mode that one has fault to trip at once to make the situation that line tripping rate is high.Still exist for long period (being generally set as 10s) earth fault after the compensation of controllable reactance transformer, think that permanent earth fault has occurred system, generally need to have a power failure and process.Now processing procedure is that automatic closed high contactor 103 drops into small resistor 104 after the ground connection duration exceedes 10s, makes protection for feed line action, by switch trip excision faulty line.Drop into after small resistor 104, controllable reactance transformer exits compensation automatically, when after faulty line isolation, system is recovered normal operation, controller 105 control appliances automatically disconnect and exit small resistor 104, therefore the input of small resistor 104 has realized accurately isolated fault circuit fast, has avoided fault extension.
Further, the high voltage connector 103 in the present embodiment is made up of two high voltage connector parallel connections.Preferably, described high voltage connector is vacuum contactor.In the time that described earth fault is permanent fault, it is closure state that described controller 105 adopts alternating current-direct current two-way power supply to control respectively two described vacuum contactors, and described small resistor 104 is accessed to described grounding transformer 101; And in the time that described permanent fault is eliminated, it is off-state that described controller 105 is controlled two described vacuum contactors, cuts off the isolation of described small resistor 104 to earth fault.
When concrete enforcement, adopt high voltage connector 103 to realize the control that small resistor 104 is dropped into and excised, for the reliability of safety action, adopt the parallel connection of two-way high voltage connector, and high voltage connector adopts respectively alternating current-direct current two-way power supply as operating mechanism power supply, by secondary device control, which has ensured controls reliability to small resistor 104.
Further, in the present embodiment, described small resistor 104 is high-power fire-resistant oxidation resistant resistance.Preferably, described high-power fire-resistant oxidation resistant resistance is stainless steel alloy resistance, and described stainless steel alloy resistance adopts grid type structure by multiple resistor discs, or described powerful fire-resistant oxidation resistant resistance adopts Modular Structure Design to form.
In the present embodiment, described controller 105 automatically cuts away described small resistor 104 before ground connection becomes zero-sequenceprotection action, and by described arc suppression coil 102, electrical network is continued to produce offset current.
Further, the time that described arc suppression coil 102 singles compensate 10kV electrical network is less than extinguishing arc time rating.
Preferably, when earth fault occurs N time described 10kV electrical network within the unit interval, in the time there is the N+1 time earth fault in described 10kV electrical network, described controller 105 exits the compensation of described arc suppression coil 102 to electrical network, and be closure state by controlling described high voltage connector 103, directly described small resistor 104 is accessed to electrical network, wherein N > 0.For example, if there is the earth fault of 3 times (and more than) in 3 minutes, " cooling time " comes into effect after ground connection for the third time, and the earth fault within " cooling time " is not carried out arc extinction compensation without exception, and directly drop into small resistor 104, proceed to high impedance status.If " cooling time " be set to 0 minute (small resistor 104 exit time delay be also set to 0 words), the situation that an earth fault occurs never and just throw small resistor 104, needs to drop into resistance after time delay forever simultaneously; " cooling time " is set to 1 minute, earth fault occurred in one minute and drop at once small resistor 104.If there is not ground connection in one minute, to lose efficacy this " cooling time ", action reverts to " ground connection---compensation---delay tripping " logic.
Especially, while when in operation of power networks, there is arbitrary faults such as " main board failures, synchronously abnormal, extremely, filtering is abnormal in triggering ", once there is ground connection, directly drop into small resistor 104, control vacuum contactor tripping operation.
In the present embodiment, after small resistor 104 drops into successfully, start timing, arrive after " resistance time rating ", force disjunction small resistor 104 (switch must select circuit breaker just effectively).Further, the present invention also carries out record to ground connection data, and wherein the content of record comprises: whether ground connection time started, ground connection end time, neutral point voltage, neutral point current, capacitance current, small resistor 104 are put into etc.; Increase the statistical function to all records, comprise statistics instantaneity ground connection and permanent earth fault (needing to drop into the earth fault of small resistor) and both proportionate relationships.
When concrete enforcement, electrical network earth fault treatment system provided by the invention also comprises a fan, for ground connection occur after start, with reduce system earth produce heat, this fan until ground connection finish to close again after rear continuous service a period of time (as 3 minutes).
The course control method for use of the 10kV electrical network earth fault that the embodiment of the present invention provides, realize the use of combining of arc suppression coil and small resistor, and application Based Intelligent Control logic realization automatically switches, and ground connection is continued to duration and judge, distinguishes instant earthing fault and permanent earth fault.Take different counter-measures for these two kinds of earth faults, both ensured the accurately isolation rapidly to permanent earth fault, avoid system power frequency overvoltage long-term existence to cause accident further to expand, can carry out fine compensation to instantaneity earth fault again dies away it, avoid repeatedly tripping, improved the safety and reliability of earth fault processing procedure.
The above is the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications are also considered as protection scope of the present invention.
Claims (10)
1. a course control method for use for 10kV electrical network earth fault, is characterized in that, comprising:
Set up into earth fault treatment system by grounding transformer with arc suppression coil, high voltage connector, small resistor and controller, and described grounding transformer is connected with 10kV electrical network bus;
In the time of described 10kV electrical network generation earth fault, grounding transformer accesses described arc suppression coil so that 10kV electrical network is compensated described in described controller control;
Described controller judges whether described earth fault is removed in limiting time; If so, judge that described earth fault is as transient earthing fault, and described in the time that ground connection is finished described in controller control arc suppression coil exit compensation; If not, judge that described earth fault is as permanent fault, and described controller is that closure state accesses described small resistor to control described grounding transformer by controlling described high voltage connector; One end ground connection of described small resistor, the other end is connected with described high voltage connector;
Described controller finishes arc suppression coil described in time control system permanent fault ground connection and exits compensation, and is that off-state is to exit described small resistor by controlling described high voltage connector.
2. the course control method for use of 10kV electrical network earth fault as claimed in claim 1, is characterized in that, describedly judges that whether described earth fault is removed in limiting time, is specially:
Detect the time that described arc suppression coil compensates 10kV electrical network;
Make-up time by described arc suppression coil to electrical network and described limiting time compare; In the time that the time that described arc suppression coil compensates 10kV electrical network exceedes described limiting time, described controller judges that described earth fault do not remove in limiting time; Otherwise described controller judges that described earth fault removes.
3. the course control method for use of 10kV electrical network earth fault as claimed in claim 2, is characterized in that, grounding transformer accesses described arc suppression coil so that 10kV electrical network is compensated described in described controller control, comprising:
Described controller calculates the inductive current that needs compensation according to the current value of the electrical network electric capacity of having measured;
Described in described controller control, arc suppression coil continues output and the described current signal that needs the inductive current equivalent compensating, and records the time that described arc suppression coil compensates 10kV electrical network.
4. the course control method for use of 10kV electrical network earth fault as claimed in claim 3, it is characterized in that, described arc suppression coil comprises a controlled reactor in short-term,, described in described controller control, grounding transformer accesses described arc suppression coil so that 10kV electrical network is compensated, and also comprises: described controller carries out real-time tracking monitoring to 10kV electrical network in real time by described controlled reactor in short-term;
In the time that power-to-ground capacitance changes, described arc suppression coil detects the variable quantity that the neutral point voltage of described grounding transformer occurs, and measures the current capacitance to earth of electrical network;
According to the variable quantity of described neutral point voltage and the current capacitance to earth of electrical network, described arc suppression coil needs the inductive current of compensation to electrical network output, to eliminate instantaneity earth fault.
5. the course control method for use of 10kV electrical network earth fault as claimed in claim 4, is characterized in that, described controlled reactor is in short-term high short-circuit impedance transformer;
Described high short-circuit impedance transformer comprises winding and secondary winding; Wherein, a described winding is as on Working winding access 10kV neutral point of electric network; Described secondary winding is the circuit being made up of the silicon controlled rectifier of two reverse parallel connections, and is connected with described controller as controlling winding;
Described controller changes between 0 to 180 degree by the angle of flow of controlling described silicon controlled rectifier, to adjust the equiva lent impedance of described silicon controlled rectifier, thereby regulates the offset current of described arc suppression coil to electrical network.
6. the course control method for use of 10kV electrical network earth fault as claimed in claim 4, is characterized in that, described high voltage connector is made up of two vacuum contactor parallel connections; ?
In the time that described earth fault is permanent fault, it is closure state that described controller adopts alternating current-direct current two-way power supply to control respectively two described vacuum contactors, and described small resistor is accessed to described grounding transformer; And in the time that described permanent fault is eliminated, two vacuum contactors described in described controller control are off-state, cut off the isolation of described small resistor to earth fault.
7. the course control method for use of 10kV electrical network earth fault as claimed in claim 6, is characterized in that, described small resistor is high-power fire-resistant oxidation resistant resistance.
8. the course control method for use of the 10kV electrical network earth fault as described in claim 1～7 any one, is characterized in that:
Described controller automatically cuts away described small resistor before ground connection becomes zero-sequenceprotection action, and by described arc suppression coil, electrical network is produced to offset current.
9. the course control method for use of 10kV electrical network earth fault as claimed in claim 8, is characterized in that: the time that described arc suppression coil single compensates 10kV electrical network is less than extinguishing arc time rating.
10. the course control method for use of 10kV electrical network earth fault as claimed in claim 1, it is characterized in that: when earth fault occurs N time described 10kV electrical network within the unit interval, in the time there is the N+1 time earth fault in described 10kV electrical network, described controller exits the compensation of described arc suppression coil to electrical network, and be closure state by controlling described high voltage connector, directly by described small resistor access electrical network, wherein N > 0.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410312600.1A CN104065056B (en) | 2014-07-01 | 2014-07-01 | A kind of course control method for use of 10kV power networks earth fault |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410312600.1A CN104065056B (en) | 2014-07-01 | 2014-07-01 | A kind of course control method for use of 10kV power networks earth fault |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104065056A true CN104065056A (en) | 2014-09-24 |
| CN104065056B CN104065056B (en) | 2017-08-25 |
Family
ID=51552644
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410312600.1A Active CN104065056B (en) | 2014-07-01 | 2014-07-01 | A kind of course control method for use of 10kV power networks earth fault |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104065056B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107317309A (en) * | 2016-04-26 | 2017-11-03 | 国网辽宁省电力有限公司大连供电公司 | A kind of earthing mode Collaborative Control conversion method and system based on GOOSE |
| CN108376970A (en) * | 2018-03-26 | 2018-08-07 | 中国电力工程顾问集团西南电力设计院有限公司 | Low-tension transformer neutral ground pattern and earth fault method for removing |
| CN108879645A (en) * | 2018-07-04 | 2018-11-23 | 国网辽宁省电力有限公司电力科学研究院 | A kind of arc suppression coil and pro-active intervention arc-extinction device paired running device and method |
| CN109347074A (en) * | 2018-08-03 | 2019-02-15 | 张安斌 | A kind of neutral grounding mode switching method |
| CN109921405A (en) * | 2019-04-24 | 2019-06-21 | 南京泰润电力工程有限公司 | A kind of earthing method of medium voltage network neutral point |
| CN112736873A (en) * | 2020-12-26 | 2021-04-30 | 广东电网有限责任公司电力科学研究院 | Capacitive current compensation method and device for neutral point of wiring network |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1588741A (en) * | 2004-07-08 | 2005-03-02 | 上海思源电气股份有限公司 | Combined automatic tracing arc extinction compensation and line selecting device |
| CN101183788A (en) * | 2007-12-11 | 2008-05-21 | 广州智光电气股份有限公司 | Power network controlled reactance and small resistor combination type earthing device |
| RU2455743C1 (en) * | 2010-12-22 | 2012-07-10 | Общество с ограниченной ответственностью Внедренческое предприятие "Наука, техника, бизнес в энергетике" | Method for increasing active current of single phase-to-ground fault in resonant grounded systems with neutral grounded via arc-suppression coil and device for such method implementation |
| CN103227463A (en) * | 2013-04-19 | 2013-07-31 | 国家电网公司 | Isolation method for single-phase earth fault |
| CN203135436U (en) * | 2013-03-31 | 2013-08-14 | 国家电网公司 | Intelligent ground resistor complete equipment |
| CN103595029A (en) * | 2013-10-24 | 2014-02-19 | 杭州智光一创科技有限公司 | Fault self-adaptive ground connecting processing system and method for distribution network power grid |
-
2014
- 2014-07-01 CN CN201410312600.1A patent/CN104065056B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1588741A (en) * | 2004-07-08 | 2005-03-02 | 上海思源电气股份有限公司 | Combined automatic tracing arc extinction compensation and line selecting device |
| CN101183788A (en) * | 2007-12-11 | 2008-05-21 | 广州智光电气股份有限公司 | Power network controlled reactance and small resistor combination type earthing device |
| RU2455743C1 (en) * | 2010-12-22 | 2012-07-10 | Общество с ограниченной ответственностью Внедренческое предприятие "Наука, техника, бизнес в энергетике" | Method for increasing active current of single phase-to-ground fault in resonant grounded systems with neutral grounded via arc-suppression coil and device for such method implementation |
| CN203135436U (en) * | 2013-03-31 | 2013-08-14 | 国家电网公司 | Intelligent ground resistor complete equipment |
| CN103227463A (en) * | 2013-04-19 | 2013-07-31 | 国家电网公司 | Isolation method for single-phase earth fault |
| CN103595029A (en) * | 2013-10-24 | 2014-02-19 | 杭州智光一创科技有限公司 | Fault self-adaptive ground connecting processing system and method for distribution network power grid |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107317309A (en) * | 2016-04-26 | 2017-11-03 | 国网辽宁省电力有限公司大连供电公司 | A kind of earthing mode Collaborative Control conversion method and system based on GOOSE |
| CN107317309B (en) * | 2016-04-26 | 2019-08-30 | 国网辽宁省电力有限公司大连供电公司 | A kind of earthing mode Collaborative Control conversion method and system based on GOOSE |
| CN108376970A (en) * | 2018-03-26 | 2018-08-07 | 中国电力工程顾问集团西南电力设计院有限公司 | Low-tension transformer neutral ground pattern and earth fault method for removing |
| CN108879645A (en) * | 2018-07-04 | 2018-11-23 | 国网辽宁省电力有限公司电力科学研究院 | A kind of arc suppression coil and pro-active intervention arc-extinction device paired running device and method |
| CN109347074A (en) * | 2018-08-03 | 2019-02-15 | 张安斌 | A kind of neutral grounding mode switching method |
| CN109921405A (en) * | 2019-04-24 | 2019-06-21 | 南京泰润电力工程有限公司 | A kind of earthing method of medium voltage network neutral point |
| CN112736873A (en) * | 2020-12-26 | 2021-04-30 | 广东电网有限责任公司电力科学研究院 | Capacitive current compensation method and device for neutral point of wiring network |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104065056B (en) | 2017-08-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103208788B (en) | Intelligent Dynamic power network neutral point earthing method and the complete sets of equipment | |
| CN106908693B (en) | Single-phase grounding route selection method of arc suppression coil grounding system with high accuracy | |
| CN204012678U (en) | A kind of power distribution network multimode ground protection system | |
| CN104065056A (en) | Process control method of 10 kV power grid ground fault | |
| CN203942275U (en) | A kind of 35kV isolated neutral power distribution network ferro resonance restraining device | |
| CN107276097A (en) | Non-effectively earthed system earth fault is mutually depressured the method for safe operation of extinguishing arc | |
| CN106655120A (en) | Intelligent ground protection method and system for neutral point of power distribution network | |
| CN103280782B (en) | The relay protecting method of failure in transformer dead zone excision | |
| CN103001195A (en) | Relay protection method capable of quickly removing dead zone fault of transformer | |
| CN110336265A (en) | Medium voltage network neutral point arc suppression coil and resistance combination earthing method | |
| CN204012685U (en) | A kind of 10kV electrical network earth fault treatment facility | |
| CN203135436U (en) | Intelligent ground resistor complete equipment | |
| CN107561408B (en) | Method for improving accuracy rate of small current ground fault line selection | |
| CN113030636B (en) | Active intervention type arc suppression device test system | |
| CN108879645A (en) | A kind of arc suppression coil and pro-active intervention arc-extinction device paired running device and method | |
| CN104009537A (en) | Box-type substation for switching between main power source and standby power source | |
| CN210693452U (en) | Neutral point grounding control device of medium-voltage power grid | |
| CN202586308U (en) | Comprehensive grounding protective device for microcomputer | |
| CN204651919U (en) | A kind of 10kV neutral point of electric network joint grounding device | |
| CN204928102U (en) | Net fault monitoring processing apparatus is joined in marriage to distributing type self -adaptation | |
| CN104821559A (en) | Neutral point joint grounding equipment self-protection method | |
| CN203025307U (en) | Smart line selector of small-current earthing system | |
| CN204012701U (en) | A kind of one-phase earthing failure in electric distribution network identification controller | |
| CN201054500Y (en) | Direction ground arc-elimination and cable selection suite device | |
| CN104749453B (en) | Reduce the method that outer net singlephase earth fault influences user's voltage dip |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |