Summary of the invention
In view of the above-mentioned problems, the present invention provides a kind of fault simulation system and method based on neutral grounding mode.
A kind of fault simulation method based on neutral grounding mode, which comprises
Construct the failure equivalent circuit based on neutral grounding mode;
New fault data is formed under neutral point difference earthing mode;
The fault data is brought into the failure equivalent circuit;
The specific failure cause of equivalent circuit is extracted according to the fault data;
Faulty line is found according to the failure cause.
Further, the correlative for forming fault data is collected, on the basis of collecting correlative, by data frame
Frame and to vertical frame carry out data opposition, determine the corresponding failure cause of fault data
Further, classify in equivalent circuit to the failure principle of neutral point difference earthing mode, then basis
Sorted failure establishes fault data frame.
Further, by the fault state of generation and neutral point by way of resonance grounding or the side of isolated neutral
The similar fault state data of the failure generated in formula extract.
Further, successively sort to the fault state under neutral point difference earthing mode according to probability of happening, i.e., according to
The mode of descending arranges.
Further, the fault state that descending arranges is arranged into data framework.
Further, the correlative for forming fault data is collected, then according to the correlation of the fault data of collection
Amount is established to vertical frame.
Further, the correlative of line fault data is collected within a certain area.
Further, correlative sort out foundation to vertical frame according to different classes of.
A kind of fault simulation system based on neutral grounding mode, the system comprises:
Data framework module: for recording the failure principle with neutral point difference earthing mode in equivalent circuit of classifying, root
Data framework module is established according to sorted failure;
Data opposition module: for collecting the correlative of line fault data, according to the correlative of the fault data of collection
Establish data opposition module;
Oppose frame module: for contrasting data frame module and opposition frame module, finding out the specific original of fault data
Cause, so that establishing failure occurs point;
The data framework module includes fault data unit and sequencing unit;
Fault data unit: fault state and neutral point for that will generate by way of resonance grounding or neutral point not
The similar fault state data of the failure generated in the mode of ground connection extract, and determine the probability of happening of fault state;
Sequencing unit: the data probability formed based on the fault data unit is arranged according to descending;
The opposition frame module includes correlative unit and data cell;
Correlative unit: delta data when for record circuit failure in route, failure phase and non-faulting in route
Delta data, fault point ground connection or instant data, the earth current in route and the electric arc disconnected of the capacitor and inductor of phase generate
Duration and electric arc stage etc. data;
Data cell: the total amount of data formed based on correlative unit within a certain area carries out line fault data
It summarizes.
The present invention is collecting correlative by establishing fault simulation system and method under neutral point difference earthing mode
On the basis of, data opposition is carried out by data framework and to vertical frame, the corresponding failure cause of fault data is determined, what a is determined
It is under the repulsion of fail result and mutually right with fault data in equivalent circuit under the situation of the fail result of route
It answers, can determine the source of fault data, to quickly confirm to failure cause, and then can quickly understand and solve
Failure cause.
Other features and advantages of the present invention will be illustrated in the following description, also, partly becomes from specification
It obtains it is clear that understand through the implementation of the invention.The objectives and other advantages of the invention can be by specification, right
Pointed structure is achieved and obtained in claim and attached drawing.
Specific embodiment
In order to make the object, technical scheme and advantages of the embodiment of the invention clearer, below in conjunction with the embodiment of the present invention
In attached drawing, technical solution in the embodiment of the present invention clearly and completely illustrated, it is clear that described embodiment is
A part of the embodiment of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, those of ordinary skill in the art
Every other embodiment obtained without making creative work, shall fall within the protection scope of the present invention.
The present invention provides a kind of fault simulation system and method based on neutral grounding mode, the present invention need to construct
Failure equivalent circuit based on neutral grounding mode, be then based on failure equivalent circuit formed fault model, neutral point not
With new fault data is formed under earthing mode, the fault data is brought into the failure equivalent circuit, according to described
Fault data extracts the specific failure cause of equivalent circuit, finally finds faulty line according to the failure cause.
The present invention is illustrated for for the Type Equivalent Circuit Model under the neutral point difference ground connection method of operation, but not
It is only limited to neutral ground to be illustrated, is also applied for other types of fault, such as the trip condition of electric appliance circuits.
Before establishing Type Equivalent Circuit Model, need to carry out each component part for establishing Type Equivalent Circuit Model data true
It is fixed, complete Type Equivalent Circuit Model data are constructed based on determining component part, each component part includes that transient state is electrical
Amount, line equivalent inductance, arc suppression coil equivalent inductance etc., wherein transient magnetic is the main work of fault transient analysis
Tool can quantitatively calculate transient state electrical quantity, be earth-fault protection, overvoltage protection, ground compensation and power network neutral point ground connection
Mode selects etc. to provide theoretical foundation;Due to line equivalent inductance and arc suppression coil equivalent inductance in different faults transition resistance and
Effect under different frequency component is different, comprehensive to establish the equivalent circuit that analyze fault signature under different situations, based on neutrality
Small current grounding fault equivalent circuit constructs attached drawing 1 under the conditions of point different faults.
As described in Figure 1, in equivalent circuit, the voltage computing formula of fault point virtual power supply is uf=-Umsin(ω0t+
φ), UmFor normal run time fault phase voltage peak value, ω0For power frequency angular frequency, φ is failure initial phase angle, and t is fault time;It can
Utilize the neutral point difference ground connection method of operation under Type Equivalent Circuit Model, wherein switch K1, switch K2 on-off with it is represented
The relationship of equivalent circuit establish table:
1 switch on and off of table and represented equivalent circuit relationship
As shown in Table 1, there is transient magnetic and power frequency etc. in neutral point resonant earthed system and isolated neutral system
Two kinds of circuit of value, when K1, K2 are all closed, there is high resistance earthing fault in resonant earthed system transient magnetic at this time, humorous
There is any resistance value ground fault in the earthed system power frequency equivalent circuit that shakes;When K1, K2 are all off, resonant earthed system at this time
There is low-impedance earthed system failure in transient magnetic, and isolated neutral system transient magnetic and isolated neutral system power frequency equivalent circuit are equal
It any resistance value ground fault is in the presence of.
As shown in Figure 1, when K1, K2 are all closed, by ufThe i that fault point virtual power supply issuesofZero-sequence current access is logical
It crossing K1 to directly flow through, is because K1 causes inductance L short-circuit not through inductance L, there is no electric currents to pass through in inductance L, and
And inductance L itself also stops electric current to pass through, then iofBy fault point ground resistance Rf, zero-sequence current iofIt is changing into ioLpReach
Inductance Lp, because resistance itself can change the size of current in route, under the certain situation of voltage, the resistance in route is got over
Greatly, then the electric current in route is smaller, when alternating current passes through inductance coil, can generate the variation of magnetic flux, so that coil can produce
Raw induced electromotive force hinders the variation of magnetic flux, and then hinders the variation of electric current, has the function that stabling current, then zero sequence
Electric current i0iC can be passed throughoiGround connection forms complete loops;
When K1, K2 are all off, by ufThe i that fault point virtual power supply issuesofZero-sequence current access is by inductance L, so
After be connected to Rf, the zero-sequence current in route is stablized by inductance L, reduces the variation degree of zero-sequence current, then zero
Sequence electric current i0iC can be passed throughoiStore electric energy.
Wherein u0For bus residual voltage;Equivalent resistance R is 2 times line mould resistance, zero moulds of the fault point to route between bus
Resistance, 2 times of power supply (main transformer) resistance and 3 times of fault point ground resistance RfThe sum of;LpIt is (3 times of arc suppression coil zero sequence equivalent inductance
Arc suppression coil inductance);L is the sum of 2 times of line mould inductance and zero mould inductance on faulty line;Select nth route for fault wire
Road, i0iFor i-th (i=0 ..., n) route zero-sequence current;CoiFor i-th (i=0 ..., n) line-to-ground zero sequence capacitor;iof、
ioLp、iCnRespectively fault point zero-sequence current, arc suppression coil zero-sequence current and faulty line capacitive earth current.
The present invention provides a fault simulation analytic process based on neutral grounding mode, and such as Fig. 2, analytical procedure is such as
Under:
Step 1: classify in equivalent circuit to the failure principle of neutral point difference earthing mode, then by basis
Sorted failure establishes fault data frame, illustratively, in the route of present isolated neutral failure, occurs one
Mutually be grounded when, if power grid continue run under the situation that a phase be grounded, non-faulting phase voltage increase, insulate weak spot be likely to by
Breakdown, and cause two-phase grounding fault, electrical equipment will be seriously damaged, failure is established into data framework:
1) the fault state under neutral point difference earthing mode is connect the fault state of generation and neutral point by resonance
The similar fault state data of the failure generated in the mode on ground or the mode of isolated neutral extract;
2) neutral point is by way of resonance grounding, i.e., one or more neutral points by the system of reactance grounded, so as to
Generally compensate the capacitive component of single-phase earth fault current;
3) mode of isolated neutral, i.e. isolated neutral or the system by high resistance grounding, also referred to as small ground connection
Current system;
4) fault state under neutral point difference earthing mode is brought into existing failure equivalent circuit, by neutral point
The fail result that fault state under different earthing modes generates in existing failure equivalent circuit according to probability of happening successively
Sequence, i.e., arrange in the way of descending;
5) fault state that descending arranges is arranged into data framework;
For the step, for the fault state of neutral point difference earthing mode, for resonance grounding and earth-free event
Hinder data, sequentially forms data framework according to the sequence that descending arranges, the present invention is by taking 10KV equivalent circuit as an example for example, simultaneously
It is not limited only to the equivalent circuit of 10KV, could be used that the equivalent circuit of other voltages.
Step 2: the correlative for forming fault data is collected, then according to the correlative of the fault data of collection
It establishes to vertical frame, illustratively, in the route of present isolated neutral failure, when phase ground connection occurs, appearance
It is another caused by overvoltage caused by gap arc, gap arc and overvoltage relatively to puncture, so that it is short two phase ground occur
Road carries out data collection to gap arc, overvoltage and two-phase grounding fault:
1) when the correlative, i.e. line fault of fault data, the capacitor and inductor of failure phase and non-faulting phase in route
Duration that delta data, fault point ground connection or the instant data disconnected, the earth current in route and electric arc generate and
Stage of electric arc etc. data;
2) correlative of line fault data is collected inside one or more county towns, by correlative according to difference
Classification, which sort out, to be established to vertical frame, illustratively, regional explanation is carried out by taking county town as an example, be not limited in county town this
Aspect;
For the step, after establishing the correlative of good fault data, collect inside one or more county towns to line fault
The correlative of data establishes correlative data to vertical frame after the specific index of the good correlative data of establishment.
Step 3: on the basis of collecting correlative, the opposition for data framework and the step 2 foundation that step 1 is established
Frame carries out data opposition, the corresponding failure cause of fault data is determined, illustratively, when present isolated neutral failure
Route in when there is gap arc or double earthfault, on the basis of illustration, it is possible to determine that present neutral point
There is the problem of single-phase earthing in phase to phase fault:
1) data oppose, i.e., form various data in the opposition specific data of lower portion and step 1 in step 2
Fault state is compareed one by one;
2) failure cause in the line fault now occurred, judges the specific failure of route according to the result of line fault
Source;
3) in equivalent circuit, after the collection by the correlative of each fault data, in data framework find with
The identical fault data of failure cause;
For the step, under the situation for determining the fail result of what a route, in equivalent circuit, in fail result
It is corresponded to each other under repulsion and with fault data, determines the source of fault data.
In the embodiment of the present invention, in small current grounding fault, there are intermittent grounding faults, illustratively, in small electricity
It flows and intermittent arc grounding failure occurs in earthed system, arc voltage electric current will occur in various degree on the basis of sine wave
Distortion: due in electric current superposition by arcing vibrate caused by transient state component, therefore every half of cycle starting when arcing can be observed
Transient current wave crest, arc voltage variation during zero stops acutely, almost maintain a constant water during stablizing arcing
It is flat, it is similar to " shape of a saddle ", there is apparent burning voltage and blowout voltage, and burning voltage is higher than blowout voltage, arc resistance
In non-linear, zero stop during resistance value it is larger, resistance value is approximately zero during arcing.
Illustratively, intermittent arcing ground phenomenon can be by power frequency blow-out theory and high-frequency extinguishing arc theoretical explanation, two kinds of reasons
By the failure mutually generation insulation breakdown at power-frequency voltage maximum value is all assumed that, the former thinks blow-out when power current zero passage, the latter
Blow-out when high-frequency current zero passage is then thought, as shown in figure 3, arc-earth faults occur every time for isolated neutral system can all draw
The higher-order of oscillation is played, to generate overvoltage, arc extinction after half of power frequency period, three-phase voltage restores sine wave, due to non-event
The free charge accumulated in barrier phase is redistributed along direct-to-ground capacitance, therefore identical positive displacement voltage is produced on three-phase, is caused
Voltage waveform integrally moves up, and after the 4th arcing, faulted phase voltage peak value is arcing transient voltage peak value, overvoltage
Much smaller during the more intermittent arcing of multiple, X-axis indicates the time slice from 0.08s to 0.22s, wherein time slice
Between be divided into 0.02s, Y-axis indicates the voltage segmentation from -20KV to 20KV, wherein is divided into 10KV, u between voltage segmentationA?
0.08s to 0.1s indicates that first segment stablizes alternating voltage, breaks down in 0.1s, the alternating voltage on the route occurs unstable
State, uBIn 0.1s to 0.16s the multiple blow-out of ground arc, restrike, there is non-faulting phase voltage and reaches in the drastic change of electromagnetic energy
To line voltage, or even line voltage is occurred more than, uCIndicate that second segment stablizes alternating voltage in 0.18s to 0.22s.
Illustratively, as shown in figure 4, and neutral by arc extinction coil grounding, can effectively delay after blow-out failure mutually electricity
The resume speed of pressure reduces the number of restriking in the unit time, reduces the multiple of intermittent arcing ground over-voltage, wherein X-axis
Indicate the time slice from 0 to 0.6s, wherein 0.1s is divided between time slice, Y-axis indicates the voltage from -20KV to 20KV
Segmentation, wherein be divided into 10KV between voltage segmentation, wherein uAIt indicates that first segment stablizes alternating voltage 0 to 0.1s, goes out in 0.1s
Show failure, unstable state, u occurs in the alternating voltage on the routeBThe electricity provided in 0.1s to 0.5s by arc suppression coil
The direct-to-ground capacitance and grounding point of sense and system constitute parallel resonance access, the inductance current compensation system capacitor electricity of arc suppression coil
Stream, makes current in the fault point be down to specified value hereinafter, preventing the expansion of accident to achieve the purpose that arc extinguishing, avoids the production of overvoltage
It is raw, uCIndicate that second segment stablizes alternating voltage in 0.5s to 0.6s.
Based on the above method, the system of solution is provided the embodiment of the invention also provides a kind of, such as Fig. 5 institute
Show, the data opposition module and the data pair of data connection are realized including data framework module, with the data framework module
Formwork erection block realizes the opposition frame module of connection, and the data framework module includes fault data unit and sequencing unit, described
The frame module that opposes includes correlative unit and data cell, in which:
The data framework module is used to record the failure principle of earthing modes different with neutral point in equivalent circuit, realizes
The data framework of failure principle, the opposition frame module are used to collect the correlative of line fault data, realize correlative
Data framework, the data opposition module find out the tool of fault data for contrasting data frame module and opposition frame module
Body reason, so that establishing failure occurs point.
The fault data unit is used to record the probability of happening of the fault state under neutral point difference earthing mode, described
Sequencing unit, the data formed based on the fault data unit are arranged according to descending, and the correlative unit is used for call wire
When the failure of road, the delta data of the capacitor and inductor of failure phase and non-faulting phase in route, fault point are grounded or disconnect instant
The stage of duration and electric arc that earth current and electric arc in data, route generate etc. data, the data cell,
Based on the total amount of data that correlative unit is formed, summarize inside one or more county towns to line fault data.
Illustratively, in a neutral point equivalent circuit, since power protection effect leads to electric brake tripping, in neutral point
Under the situation being directly grounded, if it happens when the situation of phase ground connection, biggish short circuit current will be caused, electric brake is directly jumped
It opens;And in central point isolated neutral system, once have an electric wire with contact, due to only having capacitance current to flow through, work as capacitor
When electric current is less than 5A, it can permit power supply and do not trip, if the power supply capacity of isolated neutral system is very big, service cable is very
Long, after capacitance current is greater than 5A, must trip power failure etc. failure cause once electric wire ground connection, after tripping, according to neutrality
The reason of point ground connection situation, establishes tripping possibility list, then closes a floodgate to equivalent circuit, the electricity being grounded in detection circuit
Whether capacitance current generates electric arc etc. track data, then to the route number for being equally tripping inside one or more county towns
It is summarized according to being collected, so as to the specific failure source tripped.
Although the present invention is described in detail referring to the foregoing embodiments, those skilled in the art should manage
Solution: it is still possible to modify the technical solutions described in the foregoing embodiments, or to part of technical characteristic into
Row equivalent replacement;And these are modified or replaceed, various embodiments of the present invention technology that it does not separate the essence of the corresponding technical solution
The spirit and scope of scheme.