CN105785224A

CN105785224A - Three-phase voltage signal-based power grid fault identification method and system

Info

Publication number: CN105785224A
Application number: CN201410795351.6A
Authority: CN
Inventors: 吴林林; 张家安; 刘辉; 刘宁; 李蕴红; 孟心怡; 王皓靖; 高艳红; 李轩; 刘海锋; 孙紫梅
Original assignee: State Grid Corp of China SGCC; North China Electric Power Research Institute Co Ltd; Hebei University of Technology
Current assignee: State Grid Corp of China SGCC; North China Electric Power Research Institute Co Ltd; Hebei University of Technology
Priority date: 2014-12-18
Filing date: 2014-12-18
Publication date: 2016-07-20
Anticipated expiration: 2034-12-18
Also published as: CN105785224B

Abstract

The invention provides a three-phase voltage signal-based power grid fault identification method and system. The method includes the following steps that: the three-phase voltage instantaneous signal sequence of a fan output end busbar in a power grid short-circuit fault is acquired; a fault start time point is determined according to the three-phase voltage instantaneous signal sequence; and the type of the power grid short-circuit fault is determined according to the fault start time point. According to the method of the invention, the three-phase voltage instantaneous signal sequence of the fan output end busbar in the power grid short-circuit fault is acquired; the fault start time point is determined according to the three-phase voltage instantaneous signal sequence; the type of the power grid short-circuit fault is determined according to the fault start time point; and therefore, the type of the power grid short-circuit fault can be accurately judged, and a time point when the fault occurs can be determined accurately.

Description

Electric network fault recognition methods and system based on three-phase voltage signal

Technical field

The present invention is about technical field of power systems, especially with regard to the Fault Identification technical field of wind-power electricity generation in power system, is a kind of electric network fault recognition methods based on three-phase voltage signal and system concretely.

Background technology

In recent years, China's installed capacity of wind-driven power was stepped up.Compared with the conventional power generation usage mode such as hydroelectric generation, thermal power generation, the most basic difference of wind-power electricity generation is in that its meritorious randomness, intermittence and uncontrollability exerted oneself.Along with wind generating technology is in the fast development of China, installed capacity of wind-driven power rises year by year, and wind-power electricity generation accounts for power supply proportion rapid development.

After electrical grid failure causes Voltage Drop, if the numerous and confused off-the-line of Wind turbine, network system transient state can be brought unstable, and to be likely to result in be locally even that system is paralysed comprehensively, it is grid-connected and propose low voltage crossing (LVRT) requirement accordingly that old friends begin to focus on blower fan, it is desirable to the blower fan of domestic all models will carry out low voltage crossing test before grid-connected.

So-called low voltage crossing test refers to that the manual simulation electrical network fault that is short-circuited causes blower fan grid-connected place Voltage Drop, through special time rear cutout except fault makes the process that voltage recovers gradually, checks the test of blower fan low voltage ride-through capability.Low voltage crossing test process can be measured fan outlet place three-phase voltage and three-phase current in real time.It is possible not only to analyze the low voltage crossing characteristic of blower fan by analyzing surveyed voltage and current signal, moreover it is possible to the parameter of wind-driven generator is carried out identification.

Therefore, this area is badly in need of wanting a kind of electric network fault identifying schemes based on three-phase voltage signal, and it can determine which kind of fault occurs electrical network, it is determined that the moment broken down and the moment of failure removal, as the basis carrying out subsequent parameter Identification Data Processing.

Summary of the invention

In order to solve the above-mentioned technological deficiency that prior art exists, embodiments provide a kind of electric network fault recognition methods based on three-phase voltage signal and system, by the three-phase voltage instantaneous signal sequence of blower fan outfan bus during collection short circuit malfunction, determine fault start time, and then the fault type of short circuit malfunction can be determined according to fault start time, present invention achieves and accurately judge short circuit malfunction type, and can accurately determine that the moment occurs fault.

It is an object of the invention to provide a kind of electric network fault recognition methods based on three-phase voltage signal, described method includes: the three-phase voltage instantaneous signal sequence of blower fan outfan bus during collection short circuit malfunction；Fault start time is determined according to described three-phase voltage instantaneous signal sequence；The fault type of described short circuit malfunction is determined according to described fault start time.

In a preferred embodiment of the invention, refer to during described short circuit malfunction fan outlet place occur short circuit malfunction or fan outlet place carry out the fault of low voltage crossing experimental simulation short circuit malfunction occur before, during fault and after failure removal until before voltage x current recovers fault.

In a preferred embodiment of the invention, determine that fault start time includes according to described three-phase voltage instantaneous signal sequence: obtain cycle set in advance and moment；Integrated value corresponding to described moment is determined according to described three-phase voltage instantaneous signal sequence；Obtain integral threshold set in advance and absolute value threshold value；When the described moment, corresponding integrated value was more than described integral threshold, obtain set in advance group of number；Determine the several adjacent moment of group in described moment；The described group of each self-corresponding absolute value of several adjacent moment is determined according to described three-phase voltage instantaneous signal sequence；When the described group of each self-corresponding absolute value of several adjacent moment is all higher than described absolute value threshold value, the described moment is fault start time.

In a preferred embodiment of the invention, determine that integrated value corresponding to described moment includes according to described three-phase voltage instantaneous signal sequence: selecting the described moment from described three-phase voltage instantaneous signal sequence is referred to as period 1 sequence to the three-phase voltage instantaneous signal sequence in the previous cycle；The three-phase voltage instantaneous signal sequence selected in the described period 1 sequence previous cycle from described three-phase voltage instantaneous signal sequence is referred to as sequence second round；Determine the absolute value of difference of described period 1 sequence and sequence second round；Described absolute value is integrated within the described cycle, obtains integrated value corresponding to described moment.

In a preferred embodiment of the invention, determine that the described group of each self-corresponding integrated value of several adjacent moment includes according to described three-phase voltage instantaneous signal sequence: from described three-phase voltage instantaneous signal sequence, select described adjacent moment be referred to as first group of periodic sequence to the three-phase voltage instantaneous signal sequence in the previous cycle；The three-phase voltage instantaneous signal sequence selected from described three-phase voltage instantaneous signal sequence in described first group of periodic sequence previous cycle is referred to as second group of periodic sequence；Determine the absolute value of described first group of periodic sequence and the difference of second group of periodic sequence.

In a preferred embodiment of the invention, determine that the fault type of described short circuit malfunction includes according to described fault start time: from described fault start time, determine A phase fault start time, B phase fault start time and C phase fault start time；Obtain first threshold set in advance；Determine described A phase fault start time, B phase fault start time and C phase fault start time difference between two respectively；Determine the absolute value of described difference；When the absolute value of described difference is respectively less than described first threshold, the fault type of described short circuit malfunction is three-phase shortcircuit.

In a preferred embodiment of the invention, determine that the fault type of described short circuit malfunction includes according to described fault start time: from described fault start time, determine A phase fault start time, B phase fault start time and C phase fault start time；Obtain first threshold set in advance and Second Threshold；Determine the difference of described A phase fault start time and B phase fault start time, be called the first difference；Determine the difference of described A phase fault start time and C phase fault start time, be called the second difference；Determine the difference of described B phase fault start time and C phase fault start time, be called the 3rd difference；When the absolute value of described first difference less than described first threshold, described second difference for negative and its absolute value more than described Second Threshold, described 3rd difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is C phase short trouble.

In a preferred embodiment of the invention, determine that the fault type of described short circuit malfunction also includes according to described fault start time: when described 3rd difference absolute value less than described first threshold, described first difference for just and its absolute value more than described Second Threshold, described second difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is A phase short trouble.

In a preferred embodiment of the invention, determine that the fault type of described short circuit malfunction also includes according to described fault start time: when described second difference absolute value less than described first threshold, described 3rd difference for just and its absolute value more than described Second Threshold, described first difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is B phase short trouble.

In a preferred embodiment of the invention, determine that the fault type of described short circuit malfunction also includes according to described fault start time: when described first difference absolute value less than described first threshold, described second difference for just and its absolute value more than described Second Threshold, described 3rd difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is AB phase short trouble.

In a preferred embodiment of the invention, determine that the fault type of described short circuit malfunction also includes according to described fault start time: when the absolute value of described 3rd difference less than described first threshold, described first difference for negative and its absolute value more than described Second Threshold, described second difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is BC phase short trouble.

In a preferred embodiment of the invention, determine that the fault type of described short circuit malfunction also includes according to described fault start time: when the absolute value of described second difference less than described first threshold, described 3rd difference for negative and its absolute value more than described Second Threshold, described first difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is CA phase short trouble.

It is an object of the invention to provide a kind of electric network fault identification system based on three-phase voltage signal, described system includes: instantaneous signal harvester, for gathering the three-phase voltage instantaneous signal sequence of blower fan outfan bus during short circuit malfunction；Fault start time determines device, for determining fault start time according to described three-phase voltage instantaneous signal sequence；Fault type determines device, for determining the fault type of described short circuit malfunction according to described fault start time.

In a preferred embodiment of the invention, described fault start time determines that device includes: cycle acquisition module, is used for obtaining cycle set in advance and moment；Integrated value determines module, for determining integrated value corresponding to described moment according to described three-phase voltage instantaneous signal sequence；Integral threshold module, is used for obtaining integral threshold set in advance and absolute value threshold value；Group number acquisition module, for when the described moment, corresponding integrated value was more than described integral threshold, obtaining set in advance group of number；Adjacent moment determines module, for determining the several adjacent moment of group in described moment；Absolute value determines module, for determining the described group of each self-corresponding absolute value of several adjacent moment according to described three-phase voltage instantaneous signal sequence；Fault start time determines module, and for when the described group of each self-corresponding absolute value of several adjacent moment is all higher than described absolute value threshold value, the described moment is fault start time.

In a preferred embodiment of the invention, described integrated value determines that module includes: period 1 sequence chooses unit, is referred to as period 1 sequence for selecting the described moment from described three-phase voltage instantaneous signal sequence to the three-phase voltage instantaneous signal sequence in the previous cycle；Second round, sequence chose unit, was referred to as sequence second round for the three-phase voltage instantaneous signal sequence selected in the described period 1 sequence previous cycle from described three-phase voltage instantaneous signal sequence；First absolute value determination unit, for determining the absolute value of difference of described period 1 sequence and sequence second round；Integrated value determines unit, for described absolute value is integrated within the described cycle, obtains integrated value corresponding to described moment.

In a preferred embodiment of the invention, described absolute value determines that module includes: first group of periodic sequence chooses unit, is referred to as first group of periodic sequence for selecting described adjacent moment from described three-phase voltage instantaneous signal sequence to the three-phase voltage instantaneous signal sequence in the previous cycle；Second group of periodic sequence chooses unit, is referred to as second group of periodic sequence for the three-phase voltage instantaneous signal sequence selected from described three-phase voltage instantaneous signal sequence in described first group of periodic sequence previous cycle；Second absolute value determination unit, for determining the absolute value of described first group of periodic sequence and the difference of second group of periodic sequence.

In a preferred embodiment of the invention, described fault type determines that device includes: fault start time determines module, for determining A phase fault start time, B phase fault start time and C phase fault start time from described fault start time；First threshold acquisition module, is used for obtaining first threshold set in advance；Difference determines module between two, for determining described A phase fault start time, B phase fault start time and C phase fault start time difference between two respectively；Absolute value determines module, for determining the absolute value of described difference；Fisrt fault determination type module, for when the absolute value of described difference is respectively less than described first threshold, the fault type of described short circuit malfunction is three-phase shortcircuit.

In a preferred embodiment of the invention, described fault type determines that device also includes: Second Threshold acquisition module, is used for obtaining Second Threshold set in advance；First difference determines module, for determining the difference of described A phase fault start time and B phase fault start time, is called the first difference；Second difference determines module, for determining the difference of described A phase fault start time and C phase fault start time, is called the second difference；3rd difference determines module, for determining the difference of described B phase fault start time and C phase fault start time, is called the 3rd difference；Second fault type determines module, for the absolute value when described first difference less than described first threshold, described second difference for negative and its absolute value more than described Second Threshold, described 3rd difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is C phase short trouble.

In a preferred embodiment of the invention, described fault type determines that device also includes: the 3rd fault type determines module, for when the absolute value of described 3rd difference less than described first threshold, described first difference be just and its absolute value more than described Second Threshold, described second difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is A phase short trouble.

In a preferred embodiment of the invention, described fault type determines that device also includes: the 4th fault type determines module, for when the absolute value of described second difference less than described first threshold, described 3rd difference be just and its absolute value more than described Second Threshold, described first difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is B phase short trouble.

In a preferred embodiment of the invention, described fault type determines that device also includes: the 5th fault type determines module, for when the absolute value of described first difference less than described first threshold, described second difference be just and its absolute value more than described Second Threshold, described 3rd difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is AB phase short trouble.

In a preferred embodiment of the invention, described fault type determines that device also includes: the 6th fault type determines module, for the absolute value when described 3rd difference less than described first threshold, described first difference for negative and its absolute value more than described Second Threshold, described second difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is BC phase short trouble.

In a preferred embodiment of the invention, described fault type determines that device also includes: the 7th fault type determines module, for the absolute value when described second difference less than described first threshold, described 3rd difference for negative and its absolute value more than described Second Threshold, described first difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is CA phase short trouble.

The beneficial effects of the present invention is, provide a kind of electric network fault recognition methods based on three-phase voltage signal and system, by the three-phase voltage instantaneous signal sequence of blower fan outfan bus during collection short circuit malfunction, determine fault start time, and then the fault type of short circuit malfunction can be determined according to fault start time, present invention achieves and accurately judge short circuit malfunction type, and can accurately determine that the moment occurs fault.

For the above and other purpose of the present invention, feature and advantage can be become apparent, preferred embodiment cited below particularly, and coordinate institute's accompanying drawings, it is described in detail below.

Accompanying drawing explanation

In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, the accompanying drawing used required in embodiment or description of the prior art will be briefly described below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the premise not paying creative work, it is also possible to obtain other accompanying drawing according to these accompanying drawings.

The schematic flow sheet of a kind of electric network fault recognition methods based on three-phase voltage signal that Fig. 1 provides for the embodiment of the present invention；

Fig. 2 is the particular flow sheet of the step S102 in Fig. 1；

Fig. 3 is the particular flow sheet of the step S202 in Fig. 2；

Fig. 4 is the particular flow sheet of the step S206 in Fig. 2；

Fig. 5 is the particular flow sheet of the embodiment one of the step S103 in Fig. 1；

Fig. 6 is the particular flow sheet of the embodiment two of the step S103 in Fig. 1；

Fig. 7 is the particular flow sheet of the embodiment three of the step S103 in Fig. 1；

Fig. 8 is the particular flow sheet of the embodiment four of the step S103 in Fig. 1；

Fig. 9 is the particular flow sheet of the embodiment five of the step S103 in Fig. 1；

Figure 10 is the particular flow sheet of the embodiment six of the step S103 in Fig. 1；

Figure 11 is the particular flow sheet of the embodiment seven of the step S103 in Fig. 1；

The structured flowchart of a kind of electric network fault identification system based on three-phase voltage signal that Figure 12 provides for the embodiment of the present invention；

Figure 13 a kind of determines the structured flowchart of device based on fault start time in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided；

Figure 14 a kind of determines the structured flowchart of module based on integrated value in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided；

Figure 15 a kind of determines the structured flowchart of module based on absolute value in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided；

Figure 16 a kind of determines the structured flowchart of the embodiment one of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided；

Figure 17 a kind of determines the structured flowchart of the embodiment two of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided；

Figure 18 a kind of determines the structured flowchart of the embodiment three of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided；

Figure 19 a kind of determines the structured flowchart of the embodiment four of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided；

Figure 20 a kind of determines the structured flowchart of the embodiment five of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided；

Figure 21 a kind of determines the structured flowchart of the embodiment six of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided；

Figure 22 a kind of determines the structured flowchart of the embodiment seven of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided；

Figure 23 is faulted phase voltage variation diagram one in specific embodiment；

Figure 24 is faulted phase voltage variation diagram two in specific embodiment；

Figure 25 is faulted phase voltage variation diagram three in specific embodiment；

Figure 26 is the change in voltage figure in specific embodiment in whole experimentation；

Figure 27 is the change in voltage figure of fault incipient stage in specific embodiment；

Figure 28 is the change in voltage figure in failure removal stage in specific embodiment.

Detailed description of the invention

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, it is clear that described embodiment is only a part of embodiment of the present invention, rather than whole embodiments.Based on the embodiment in the present invention, the every other embodiment that those of ordinary skill in the art obtain under not making creative work premise, broadly fall into the scope of protection of the invention.

The most primary task determines which kind of fault occurs electrical network before to the many specificity analysises of wind energy conversion system, next to that determine the moment of moment and the failure removal broken down.These two tasks are by the basis of subsequent parameter Identification Data Processing.

The method being currently generally adopted is, first asks for the virtual value of every voltage, then thinks the fault that is short-circuited when voltage effective value falls, and falls degree by relatively each phase voltage virtual value, judges the type of short trouble.Concrete principle is as follows:

In blower fan low voltage crossing test process, fan outlet terminal voltage signal can experience following three steady statue: A. voltage normal condition, B. malfunction, C. voltage normal condition.Have the complicated transient process of about 0.1 second when voltage is from A condition to B state transition, during from B state to C process transitions, have the transient process of 0.01 second.In the faulted phase voltage variation diagram one shown in Figure 23, Figure 24, Figure 25, faulted phase voltage variation diagram two, faulted phase voltage variation diagram three, before A condition refers to the t1 moment, after B state refers to that t2 to t3, C-state refer to t4.

For A phase, A phase voltage is under normal circumstances

Wherein, Um is amplitude, f=50Hz.

Voltage effective value computing formula is

U_{A} = \sqrt{\frac{1}{T} {&Integral;}_{0}^{T} {ua}^{2} dt} - - - (2)

When voltage is normal

U_{A} = \frac{U_{m}}{\sqrt{2}} - - - (2)

Have that the feature of SIN function is known also can seek voltage effective value with following formula

U_{A} = \sqrt{\frac{2}{T} {&Integral;}_{0}^{T / 2} {ua}^{2} dt} - - - (4)

When voltage is normal

U_{A} = \frac{U_{m}}{\sqrt{2}} - - - (5)

The voltage signal measured in practice is discrete point, until voltage x current recovers pre-fault status every Δ t (Δ t it suffices that the Δ t < 0.005s) time before fault occurs, during fault and after failure removal, the three-phase voltage instantaneous signal sequential value of Real-time Collection blower fan outfan bus, it may be assumed that

A phase voltage instantaneous signal sequential value is: u_A(t₁)、u_A(t₂)、u_A(t₃)、…、u_A(t_n)

B phase voltage instantaneous signal sequential value is: u_B(t₁)、u_B(t₂)、u_B(t₃)、…、u_B(t_n)

C phase voltage instantaneous signal sequential value is: u_C(t₁)、u_C(t₂)、u_C(t₃)、…、u_C(t_n)

Wherein t₁、t₂、t₃、…、t_nRepresenting the moment gathering each signal of telecommunication respectively, interval is Δ t successively.

Formula now by the voltage effective value in (2) formula calculating t0 moment is

U_{A} (t 0) = \sqrt{\frac{1}{t 2 - t 1} \underset{t 1 \leq t < t 2}{Σ} u {(t)}_{a}^{2} Δt} - - - (6)

Wherein, t1=t0-T/2, t2=t0+T/2, T is the cycle of voltage.

Formula now by the voltage effective value in (4) formula calculating t0 moment is

U_{A} (t 0) = \sqrt{\frac{1}{t 2 - t 1} \underset{t 1 \leq t < t 2}{Σ} u {(t)}_{a}^{2} Δt} - - - (7)

Wherein, t1=t0-T/4, t2=t0+T/4, T is the cycle of voltage

To (6) formula result of calculation called after t0 moment A phase voltage virtual value in the present invention, to (7) formula result of calculation then called after t0 moment A phase voltage half-wave virtual value.

Instantaneous voltage curve that what Figure 26, Figure 27, Figure 28 showed is measures, half-wave virtual value curve, virtual value curve and by the instantaneous voltage image measured to the constitutional diagram of one cycle curve obtained of right translation.

By Figure 26, Figure 27, Figure 28 and combine (6) formula and (7) formula, it can be deduced that as drawn a conclusion:

(1) being increased by virtual value or reduce the time (hereinafter virtual value method) coming failure judgement generation or excision, error is 0～0.5 cycle, i.e. 0～0.01s.

(2) increased or reduced the moment (hereinafter half-wave virtual value method) coming failure judgement generation or excision by half-wave virtual value, error is 0～0.25 cycle, i.e. 0～0.005s.

(3) moment (curve ratio relatively method name can restart hereinafter) of failure judgement generation or excision is carried out by comparing the difference of this cycle instantaneous voltage and a upper periodic voltage instantaneous value, if threshold value selects suitable, error can taper to 2 Δ t～10 Δ t (Δ t is the sampling period).

During the core concept of curve relative method: by instantaneous voltage curve with instantaneous voltage curve is compared to one cycle curve obtained of right translation, when two curves first times continue to have relatively large deviation, then it is assumed that be fault start time when just having begun with deviation.The complicated transient process between voltage normal condition and malfunction is avoided after judging fault start time, start again at from stable malfunction and compare two curves, when two curves continue to have relatively large deviation again, then it is assumed that be the failure removal moment when just having begun with deviation.

Two above-mentioned curve ratio were relatively equivalent to the instantaneous voltage in this cycle compared with the instantaneous voltage in the upper cycle.Two above-mentioned curve deviations can characterize with the integration of the absolute value of instantaneous voltage difference in two cycles, then thinks that when this integrated value (being equivalent to the area between two lines) is more than a certain threshold value fault occurred within this cycle.Instantaneous voltage on two cycle same phases is made difference and the threshold value with setting that takes absolute value is made comparisons, after the absolute value of the difference of certain data exceedes threshold value, the absolute value of the difference of several data continues to exceed threshold value afterwards, then it is assumed that moment corresponding to first data is fault moment to be determined or failure removal moment.

Owing to the impact of healthy phases is had a small delay by fault phase, therefore can according to the first failure judgement type later of each fault moment.When the fault moment of a certain phase is substantially early than other biphase fault moments, and additionally biphase fault moment is close, then it is believed that there occurs single-phase short circuit；When the fault moment of a certain phase is substantially later than other biphase fault moments, and additionally biphase fault moment is close, then it is believed that there occurs line to line fault；When the fault moment all similar of three-phase, then it is believed that there occurs three-phase shortcircuit.

Virtual value method and half-wave virtual value method described in above-mentioned principal portion are capable of the judgement of fault moment and the judgement of fault type.But computationally intensive during the failure judgement moment, and bigger error.

The main purpose of the embodiment of the present invention is in that to provide a kind of electric network fault recognition methods based on three-phase voltage signal and system, accurately to judge short circuit malfunction type, and can accurately determine that the moment occurs fault.

The schematic flow sheet of a kind of electric network fault recognition methods based on three-phase voltage signal that Fig. 1 provides for the embodiment of the present invention, as shown in Figure 1, the method includes:

S101: the three-phase voltage instantaneous signal sequence of blower fan outfan bus during collection short circuit malfunction.Refer to during described short circuit malfunction fan outlet place occur short circuit malfunction or fan outlet place carry out the fault of low voltage crossing experimental simulation short circuit malfunction occur before, during fault and after failure removal until before voltage x current recovers fault.

In a particular embodiment, when three-phase voltage instantaneous signal sequence refers to short circuit malfunction occurs at fan outlet place or carries out simulating grid short trouble during low voltage crossing experiment, until voltage x current recovers pre-fault status every Δ t (Δ t it suffices that the Δ t < 0.005s) time before fault occurs, during fault and after failure removal, the three-phase voltage instantaneous signal sequential value of Real-time Collection blower fan outfan bus, the three-phase voltage signal that the sampling period is Δ t is as follows:

S102: determine fault start time according to described three-phase voltage instantaneous signal sequence.

S103: determine the fault type of described short circuit malfunction according to described fault start time.

Because no matter being electrical network generation single-phase short circuit or line to line fault, not breaking down and mutually there will be voltage pulsation yet, define healthy phases fault at this and occur moment and failure removal moment to refer to be affected by fault and moment that voltage pulsation occurs.Fig. 2 is the particular flow sheet of the step S102 in Fig. 1, and as shown in Figure 2, step S102 includes:

S201: obtain cycle set in advance and moment.

In a particular embodiment, if the cycle is T=20ms, the moment is t, and the sampling period is Δ t=0.1ms.

S202: determine integrated value corresponding to described moment according to described three-phase voltage instantaneous signal sequence.Fig. 3 is the particular flow sheet of step S202, and in a particular embodiment, integrated value corresponding to described moment is data3.From the figure 3, it may be seen that step S202 includes:

S301: selecting the described moment from described three-phase voltage instantaneous signal sequence is referred to as period 1 sequence to the three-phase voltage instantaneous signal sequence in the previous cycle；

In a particular embodiment, if the cycle is T=20ms, the moment is t, and the sampling period is Δ t=0.1ms.From three-phase voltage instantaneous signal sequence, then obtain t to the three-phase voltage instantaneous signal sequence in the previous cycle and period 1 sequence data1.

S302: the three-phase voltage instantaneous signal sequence selected in the described period 1 sequence previous cycle from described three-phase voltage instantaneous signal sequence is referred to as sequence second round；

In a particular embodiment, if the cycle is T=20ms, the moment is t, and the sampling period is Δ t=0.1ms.The three-phase voltage instantaneous signal sequence then obtained in the period 1 sequence previous cycle from three-phase voltage instantaneous signal sequence is referred to as sequence second round, i.e. data2.

Owing to each t only increases Δ t, so actually data1 and data2 only abandons in the respective cycle voltage data the earliest when updating, additionally increase a voltage data that t is corresponding instantly.So in data with being newly adopt to keep other data not change, simply deleting data increases data, improves program operational efficiency with this.

S303: determine the absolute value of difference of described period 1 sequence and sequence second round；

S304: described absolute value is integrated within the described cycle, obtains integrated value corresponding to described moment.

In a particular embodiment, i.e. right | data1-data2 | integration within a cycle, integrated value is data3.The actual area characterizing the misaligned rear folded part of curve data1 and data2 of data3.

Amplitude Um=563V, the cycle is T=20ms, and the sampling period is Δ t=0.1ms, then a cycle single-phase voltage data volume is 200.For A phase voltage:

T=t40 time initial

Time initial, the data in data1 are: u_A(t₂₀₁)、u_A(t₂₀₂)、u_A(t₂₀₃)、…、u_A(t₄₀₀)

Time initial, the data in data2 are: u_A(t₁)、u_A(t₂)、u_A(t₃)、…、u_A(t₂₀₀)

Then data3=| u_A(t₂₀₁)-u_A(t₁)|+|u_A(t₂₀₂)-u_A(t₂)|+…+|u_A(t₄₀₀)-u_A(t₂₀₀)|。

As shown in Figure 2, step S102 also includes:

S203: obtain integral threshold set in advance and absolute value threshold value, integral threshold is set to ε, and absolute value threshold value is set to δ.

S204: when the described moment, corresponding integrated value was more than described integral threshold, obtain set in advance group of number.

In a particular embodiment, such as set in advance group of number is 6.

In a particular embodiment, when the integrated value that the described moment is corresponding is not more than described integral threshold, t adds Δ t, continues to judge t is more than or equal to whether end time tn sets up, if then terminating, then performs step S202 if not.

S205: determine the several adjacent moment of group in described moment, namely determines 6 adjacent moment of moment t.

S206: determine the described group of each self-corresponding absolute value of several adjacent moment according to described three-phase voltage instantaneous signal sequence.Fig. 4 is the particular flow sheet of step S202, and as shown in Figure 4, step S206 includes:

S401: select described adjacent moment from described three-phase voltage instantaneous signal sequence and be referred to as first group of periodic sequence to the three-phase voltage instantaneous signal sequence in the previous cycle；

In a particular embodiment, if the cycle is T=20ms, the moment is t, and the sampling period is Δ t=0.1ms.From three-phase voltage instantaneous signal sequence, then obtain the adjacent moment of t to the three-phase voltage instantaneous signal sequence i.e. first group of periodic sequence in the previous cycle.

S402: the three-phase voltage instantaneous signal sequence selected from described three-phase voltage instantaneous signal sequence in described first group of periodic sequence previous cycle is referred to as second group of periodic sequence；

In a particular embodiment, if the cycle is T=20ms, the moment is t, and the sampling period is Δ t=0.1ms.The three-phase voltage instantaneous signal sequence then obtained from three-phase voltage instantaneous signal sequence in first group of periodic sequence previous cycle is referred to as second group of periodic sequence.

S403: determine the absolute value of described first group of periodic sequence and the difference of second group of periodic sequence.

As shown in Figure 2, step S102 also includes:

S207: when the described group of each self-corresponding absolute value of several adjacent moment is all higher than described absolute value threshold value, the described moment is fault start time.

In a particular embodiment, it is assumed that judge as t=tm1 in step S204, data3 is for the first time more than integral threshold ε, now:

Data in data1 are u_A(tm1-199Δt)、u_A(tm1-198Δt)、u_A(tm1-197Δt、…、u_A(tm1)

Data in data2 are u_A(tm1-399Δt)、u_A(tm1-398Δt)、u_A(tm1-397Δt)、…、u_A(tm1-200Δt)。

Then the tm1 moment has occurred and that fault, and now each self-corresponding absolute value of the several adjacent moment of calculating group respectively, concrete, and the absolute value that step S403 determines is | u_A(tm1-199Δt)-u_A(tm1-399Δt)|、|u_A(tm1-198Δt)-u_A(tm1-398Δt)|、|u_A(tm1-197Δt)-u_A(tm1-397Δt)|、…、|u_A(tm1)-u_A(tm1-290Δt)|。

Utilize same method can obtain tb1, tc1, then overall fault start time T=min (ta1, tb1, tc1).

Above step, determines except fault start time according to described three-phase voltage instantaneous signal sequence, determines the fault type of described short circuit malfunction according to described fault start time.Concrete, compare the priority time failure judgement type that three-phase voltage signal fault starts.Owing to the impact of healthy phases is had a small delay by fault phase, therefore can according to the first failure judgement type later of each fault moment.When the fault moment of a certain phase is substantially early than other biphase fault moments, and additionally biphase fault moment is close, then it is believed that there occurs single-phase short circuit；When the fault moment of a certain phase is substantially later than other biphase fault moments, and additionally biphase fault moment is close, then it is believed that there occurs line to line fault；When the fault moment all similar of three-phase, then it is believed that there occurs three-phase shortcircuit.It is introduced one by one below in conjunction with accompanying drawing.

Fig. 5 is the particular flow sheet of the embodiment one of the step S103 in Fig. 1, and as shown in Figure 5, this step specifically includes in embodiment one:

S501: determine A phase fault start time, B phase fault start time and C phase fault start time from described fault start time.In a particular embodiment, overall fault start time T=min (ta1, tb1, tc1) determined in step S102, therefrom extract A phase fault start time ta1, B phase fault start time tb1 and C phase fault start time tc1.

S502: obtain first threshold set in advance, in a particular embodiment, first threshold can preset according to practical experience value, and such as first threshold is 1ms.

S503: determine described A phase fault start time, B phase fault start time and C phase fault start time difference between two respectively；

S504: determine the absolute value of described difference；

S505: when the absolute value of described difference is respectively less than described first threshold, the fault type of described short circuit malfunction is three-phase shortcircuit.

Fig. 6 is the particular flow sheet of the embodiment two of the step S103 in Fig. 1, and this step specifically includes in embodiment two:

S601: determine A phase fault start time, B phase fault start time and C phase fault start time from described fault start time.In a particular embodiment, overall fault start time T=min (ta1, tb1, tc1) determined in step S102, therefrom extract A phase fault start time ta1, B phase fault start time tb1 and C phase fault start time tc1.

S602: obtain first threshold set in advance and Second Threshold, in a particular embodiment, first threshold, Second Threshold can preset according to practical experience value, and such as first threshold is 1ms, and Second Threshold is 2ms.

S603: determine the difference of described A phase fault start time and B phase fault start time, be called the first difference；

S604: determine the difference of described A phase fault start time and C phase fault start time, be called the second difference；

S605: determine the difference of described B phase fault start time and C phase fault start time, be called the 3rd difference；

S606: when the absolute value of described first difference less than described first threshold, described second difference for negative and its absolute value more than described Second Threshold, described 3rd difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is C phase short trouble.

Namely, in a particular embodiment, when | ta1-tb1 | less than described first threshold, | ta1-tc1 | more than described Second Threshold and ta1 less than tc1, | tb1-tc1 | more than described Second Threshold and tb1 less than tc1 time, it is believed that ta1 and tb1 approximately equal, ta1 is significantly less than tc1, tb1 is significantly less than tc1, then the fault type of short circuit malfunction is C phase short trouble.

Fig. 7 is the particular flow sheet of the embodiment three of the step S103 in Fig. 1, and this step specifically includes in embodiment three:

S701: determine A phase fault start time, B phase fault start time and C phase fault start time from described fault start time.In a particular embodiment, overall fault start time T=min (ta1, tb1, tc1) determined in step S102, therefrom extract A phase fault start time ta1, B phase fault start time tb1 and C phase fault start time tc1.

S702: obtain first threshold set in advance and Second Threshold, in a particular embodiment, first threshold, Second Threshold can preset according to practical experience value, and such as first threshold is 1ms, and Second Threshold is 2ms.

S703: determine the difference of described A phase fault start time and B phase fault start time, be called the first difference；

S704: determine the difference of described A phase fault start time and C phase fault start time, be called the second difference；

S705: determine the difference of described B phase fault start time and C phase fault start time, be called the 3rd difference；

S706: when described 3rd difference absolute value less than described first threshold, described first difference be just and its absolute value more than described Second Threshold, described second difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is A phase short trouble.

Namely, in a particular embodiment, when | ta1-tb1 | more than described Second Threshold and ta1 more than tb1, | ta1-tc1 | more than described Second Threshold and ta1 more than tc1, | tb1-tc1 | less than described first threshold time, it is believed that tb1 and tc1 approximately equal, tb1 is significantly less than ta1, tc1 is significantly less than ta1, then the fault type of short circuit malfunction is A phase short trouble.

Fig. 8 is the particular flow sheet of the embodiment four of the step S103 in Fig. 1, and this step specifically includes in embodiment four:

S801: determine A phase fault start time, B phase fault start time and C phase fault start time from described fault start time.In a particular embodiment, overall fault start time T=min (ta1, tb1, tc1) determined in step S102, therefrom extract A phase fault start time ta1, B phase fault start time tb1 and C phase fault start time tc1.

S802: obtain first threshold set in advance and Second Threshold, in a particular embodiment, first threshold, Second Threshold can preset according to practical experience value, and such as first threshold is 1ms, and Second Threshold is 2ms.

S803: determine the difference of described A phase fault start time and B phase fault start time, be called the first difference；

S804: determine the difference of described A phase fault start time and C phase fault start time, be called the second difference；

S805: determine the difference of described B phase fault start time and C phase fault start time, be called the 3rd difference；

S806: when described second difference absolute value less than described first threshold, described 3rd difference be just and its absolute value more than described Second Threshold, described first difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is B phase short trouble.

Namely, in a particular embodiment, when | ta1-tb1 | more than described Second Threshold and a1 less than tb1, | ta1-tc1 | less than described first threshold, | tb1-tc1 | more than described Second Threshold and tb1 more than tc1 time, it is believed that tc1 and ta1 approximately equal, tc1 is significantly less than tb1, ta1 is significantly less than tb1, then the fault type of short circuit malfunction is B phase short trouble.

In above-mentioned embodiment two to embodiment four, A phase short trouble, B phase short trouble, C phase short trouble are referred to as single-phase earthing fault.

Fig. 9 is the particular flow sheet of the embodiment five of the step S103 in Fig. 1, and this step specifically includes in embodiment five:

S901: determine A phase fault start time, B phase fault start time and C phase fault start time from described fault start time.In a particular embodiment, overall fault start time T=min (ta1, tb1, tc1) determined in step S102, therefrom extract A phase fault start time ta1, B phase fault start time tb1 and C phase fault start time tc1.

S902: obtain first threshold set in advance and Second Threshold, in a particular embodiment, first threshold, Second Threshold can preset according to practical experience value, and such as first threshold is 1ms, and Second Threshold is 2ms.

S903: determine the difference of described A phase fault start time and B phase fault start time, be called the first difference；

S904: determine the difference of described A phase fault start time and C phase fault start time, be called the second difference；

S905: determine the difference of described B phase fault start time and C phase fault start time, be called the 3rd difference；

S906: when described first difference absolute value less than described first threshold, described second difference be just and its absolute value more than described Second Threshold, described 3rd difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is AB phase short trouble.

Namely, in a particular embodiment, when | ta1-tb1 | less than described first threshold, | ta1-tc1 | more than described Second Threshold and ta1 more than tc1, | tb1-tc1 | more than described Second Threshold and tb1 more than tc1 time, it is believed that ta1 and tb1 approximately equal, ta1 is significantly greater than tc1, tb1 is significantly greater than tc1, then the fault type of short circuit malfunction is AB phase short trouble.

Figure 10 is the particular flow sheet of the embodiment six of the step S103 in Fig. 1, and this step specifically includes in embodiment six:

S1001: determine A phase fault start time, B phase fault start time and C phase fault start time from described fault start time.In a particular embodiment, overall fault start time T=min (ta1, tb1, tc1) determined in step S102, therefrom extract A phase fault start time ta1, B phase fault start time tb1 and C phase fault start time tc1.

S1002: obtain first threshold set in advance and Second Threshold, in a particular embodiment, first threshold, Second Threshold can preset according to practical experience value, and such as first threshold is 1ms, and Second Threshold is 2ms.

S1003: determine the difference of described A phase fault start time and B phase fault start time, be called the first difference；

S1004: determine the difference of described A phase fault start time and C phase fault start time, be called the second difference；

S1005: determine the difference of described B phase fault start time and C phase fault start time, be called the 3rd difference；

S1006: when the absolute value of described 3rd difference less than described first threshold, described first difference for negative and its absolute value more than described Second Threshold, described second difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is BC phase short trouble.

Namely, in a particular embodiment, when | ta1-tb1 | more than described Second Threshold and a1 less than tb1, | ta1-tc1 | more than described Second Threshold and ta1 less than tb1, | tb1-tc1 | less than described first threshold time, it is believed that tb1 and tc1 approximately equal, tb1 is significantly greater than ta1, tc1 is significantly greater than ta1, then the fault type of short circuit malfunction is BC phase short trouble.

Figure 11 is the particular flow sheet of the embodiment seven of the step S103 in Fig. 1, and this step specifically includes in embodiment seven:

S1101: determine A phase fault start time, B phase fault start time and C phase fault start time from described fault start time.In a particular embodiment, overall fault start time T=min (ta1, tb1, tc1) determined in step S102, therefrom extract A phase fault start time ta1, B phase fault start time tb1 and C phase fault start time tc1.

S1102: obtain first threshold set in advance and Second Threshold, in a particular embodiment, first threshold, Second Threshold can preset according to practical experience value, and such as first threshold is 1ms, and Second Threshold is 2ms.

S1103: determine the difference of described A phase fault start time and B phase fault start time, be called the first difference；

S1104: determine the difference of described A phase fault start time and C phase fault start time, be called the second difference；

S1105: determine the difference of described B phase fault start time and C phase fault start time, be called the 3rd difference；

S1106: when the absolute value of described second difference less than described first threshold, described 3rd difference for negative and its absolute value more than described Second Threshold, described first difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is CA phase short trouble.

Namely, in a particular embodiment, when | ta1-tb1 | more than described Second Threshold and a1 more than tb1, | ta1-tc1 | less than described first threshold, | tb1-tc1 | more than described Second Threshold and tb1 less than tc1 time, it is believed that tc1 and ta1 approximately equal, tc1 is significantly greater than tb1, ta1 is significantly greater than tb1, then the fault type of short circuit malfunction is CA phase short trouble.

In above-mentioned embodiment five to embodiment seven, AB two-phase short-circuit fault, BC two-phase short-circuit fault, CA two-phase short-circuit fault is referred to as two-phase short-circuit fault.

Above, namely it is a kind of electric network fault recognition methods based on three-phase voltage signal provided by the invention, by the three-phase voltage instantaneous signal sequence of blower fan outfan bus during collection short circuit malfunction, determine fault start time, and then the fault type of short circuit malfunction can be determined according to fault start time, present invention achieves and accurately judge short circuit malfunction type, and can accurately determine that the moment occurs fault.

The structured flowchart of a kind of electric network fault identification system based on three-phase voltage signal that Figure 12 provides for the embodiment of the present invention, as shown in Figure 12, this system includes:

Instantaneous signal harvester 101, for gathering the three-phase voltage instantaneous signal sequence of blower fan outfan bus during short circuit malfunction.Refer to during described short circuit malfunction fan outlet place occur short circuit malfunction or fan outlet place carry out the fault of low voltage crossing experimental simulation short circuit malfunction occur before, during fault and after failure removal until before voltage x current recovers fault.

Fault start time determines device 102, for determining fault start time according to described three-phase voltage instantaneous signal sequence.

Fault type determines device 103, for determining the fault type of described short circuit malfunction according to described fault start time.

Because no matter being electrical network generation single-phase short circuit or line to line fault, not breaking down and mutually there will be voltage pulsation yet, define healthy phases fault at this and occur moment and failure removal moment to refer to be affected by fault and moment that voltage pulsation occurs.Figure 13 a kind of determines the structured flowchart of device based on fault start time in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided, and as shown in Figure 13, fault start time determines that device 102 includes:

Cycle acquisition module 201, is used for obtaining cycle set in advance and moment.

Score value determines module 202, for determining integrated value corresponding to described moment according to described three-phase voltage instantaneous signal sequence.Figure 14 a kind of determines the structured flowchart of module based on integrated value in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided, and in a particular embodiment, integrated value corresponding to described moment is data3.As shown in Figure 14, integrated value determines that module 202 includes:

Period 1 sequence chooses unit 301, is referred to as period 1 sequence for selecting the described moment from described three-phase voltage instantaneous signal sequence to the three-phase voltage instantaneous signal sequence in the previous cycle；

Second round, sequence chose unit 302, was referred to as sequence second round for the three-phase voltage instantaneous signal sequence selected in the described period 1 sequence previous cycle from described three-phase voltage instantaneous signal sequence；

First absolute value determination unit 303, for determining the absolute value of difference of described period 1 sequence and sequence second round；

Integrated value determines unit 304, for described absolute value is integrated within the described cycle, obtains integrated value corresponding to described moment.

T=t40 time initial

As shown in Figure 13, fault start time determines that device 102 also includes:

Integral threshold module 203, is used for obtaining integral threshold set in advance and absolute value threshold value, and integral threshold is set to ε, and absolute value threshold value is set to δ.

Group number acquisition module 204, for when the described moment, corresponding integrated value was more than described integral threshold, obtaining set in advance group of number.

In a particular embodiment, such as set in advance group of number is 6.

Adjacent moment determines module 205, for determining the several adjacent moment of group in described moment, namely determines 6 adjacent moment of moment t.

Absolute value determines module 206, for determining the described group of each self-corresponding absolute value of several adjacent moment according to described three-phase voltage instantaneous signal sequence.Figure 15 a kind of determines the structured flowchart of module based on absolute value in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided, and as shown in Figure 15, absolute value determines that module 206 includes:

First group of periodic sequence chooses unit 401, is referred to as first group of periodic sequence for selecting described adjacent moment from described three-phase voltage instantaneous signal sequence to the three-phase voltage instantaneous signal sequence in the previous cycle；

Second group of periodic sequence chooses unit 402, is referred to as second group of periodic sequence for the three-phase voltage instantaneous signal sequence selected from described three-phase voltage instantaneous signal sequence in described first group of periodic sequence previous cycle；

Absolute value determination unit 403, for determining the absolute value of described first group of periodic sequence and the difference of second group of periodic sequence.

Fault start time determines module 207, and for when the described group of each self-corresponding absolute value of several adjacent moment is all higher than described absolute value threshold value, the described moment is fault start time.

Then the tm1 moment has occurred and that fault, and now each self-corresponding absolute value of the several adjacent moment of calculating group respectively, concrete, and the absolute value that step S403 determines is | u_A(tm1-199Δt)-u_A(tm1-399Δt)|、|u_A(tm1-198Δt)-u_A(tm1-398Δt)|、|u_A(tm1-197Δt)-u_A(tm1-397Δt)|、…、|u_A(tm1)-u_A(tm1-200Δt)|。

Apparatus above, determines except fault start time according to described three-phase voltage instantaneous signal sequence, determines the fault type of described short circuit malfunction according to described fault start time.Concrete, compare the priority time failure judgement type that three-phase voltage signal fault starts.Owing to the impact of healthy phases is had a small delay by fault phase, therefore can according to the first failure judgement type later of each fault moment.When the fault moment of a certain phase is substantially early than other biphase fault moments, and additionally biphase fault moment is close, then it is believed that there occurs single-phase short circuit；When the fault moment of a certain phase is substantially later than other biphase fault moments, and additionally biphase fault moment is close, then it is believed that there occurs line to line fault；When the fault moment all similar of three-phase, then it is believed that there occurs three-phase shortcircuit.It is introduced one by one below in conjunction with accompanying drawing.

Figure 16 a kind of determines the structured flowchart of the embodiment one of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided, and as shown in Figure 16, this device specifically includes in embodiment one:

Fault start time determines module 501, for determining A phase fault start time, B phase fault start time and C phase fault start time from described fault start time.In a particular embodiment, overall fault start time T=min (ta1, tb1, tc1) determined in step S102, therefrom extract A phase fault start time ta1, B phase fault start time tb1 and C phase fault start time tc1.

First threshold acquisition module 502, is used for obtaining first threshold set in advance, and in a particular embodiment, first threshold can preset according to practical experience value, and such as first threshold is 1ms.

Difference determines module 503 between two, for determining described A phase fault start time, B phase fault start time and C phase fault start time difference between two respectively；

Absolute value determines module 504, for determining the absolute value of described difference；

Fisrt fault determination type module 505, for when the absolute value of described difference is respectively less than described first threshold, the fault type of described short circuit malfunction is three-phase shortcircuit.

Figure 17 a kind of determines the structured flowchart of the embodiment two of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided, and this device specifically includes in embodiment two:

Second Threshold acquisition module 506, is used for obtaining Second Threshold set in advance, and in a particular embodiment, Second Threshold can preset according to practical experience value, and such as Second Threshold is 2ms.

First difference determines module 507, for determining the difference of described A phase fault start time and B phase fault start time, is called the first difference；

Second difference determines module 508, for determining the difference of described A phase fault start time and C phase fault start time, is called the second difference；

3rd difference determines module 509, for determining the difference of described B phase fault start time and C phase fault start time, is called the 3rd difference；

Second fault type determines module 510, for the absolute value when described first difference less than described first threshold, described second difference for negative and its absolute value more than described Second Threshold, described 3rd difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is C phase short trouble.

Figure 18 a kind of determines the structured flowchart of the embodiment three of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided, and this device specifically includes in embodiment three:

3rd fault type determines module 511, for when the absolute value of described 3rd difference less than described first threshold, described first difference be just and its absolute value more than described Second Threshold, described second difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is A phase short trouble.

Figure 19 a kind of determines the structured flowchart of the embodiment four of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided, and this device specifically includes in embodiment four:

4th fault type determines module 512, for when the absolute value of described second difference less than described first threshold, described 3rd difference be just and its absolute value more than described Second Threshold, described first difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is B phase short trouble.

Namely, in a particular embodiment, when | ta1-tb1 | more than described Second Threshold and a1 less than tb1, | ta1-tc1 | less than described first threshold, | ta1-tc1 | more than described Second Threshold and tb1 more than tc1 time, it is believed that tc1 and ta1 approximately equal, tc1 is significantly less than tb1, ta1 is significantly less than tb1, then the fault type of short circuit malfunction is B phase short trouble.

Figure 20 a kind of determines the structured flowchart of the embodiment five of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided, and this device specifically includes in embodiment five:

5th fault type determines module 513, for when the absolute value of described first difference less than described first threshold, described second difference be just and its absolute value more than described Second Threshold, described 3rd difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is AB phase short trouble.

Figure 21 a kind of determines the structured flowchart of the embodiment six of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided, and this device specifically includes in embodiment six:

6th fault type determines module 514, for the absolute value when described 3rd difference less than described first threshold, described first difference for negative and its absolute value more than described Second Threshold, described second difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is BC phase short trouble.

Figure 22 a kind of determines the structured flowchart of the embodiment seven of device based on fault type in the electric network fault identification system of three-phase voltage signal for what the embodiment of the present invention provided, and this device specifically includes in embodiment seven:

7th fault type determines module 515, for the absolute value when described second difference less than described first threshold, described 3rd difference for negative and its absolute value more than described Second Threshold, described first difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is CA phase short trouble.

Namely, in a particular embodiment, when | ta1-tb1 | more than described Second Threshold and a1 more than tb1, | ta1-tc1 | less than described first threshold, | tb1*tc1 | more than described Second Threshold and tb1 less than tc1 time, it is believed that tc1 and ta1 approximately equal, tc1 is significantly greater than tb1, ta1 is significantly greater than tb1, then the fault type of short circuit malfunction is CA phase short trouble.

Above, namely it is a kind of electric network fault identification system based on three-phase voltage signal provided by the invention, by the three-phase voltage instantaneous signal sequence of blower fan outfan bus during collection short circuit malfunction, determine fault start time, and then the fault type of short circuit malfunction can be determined according to fault start time, present invention achieves and accurately judge short circuit malfunction type, and can accurately determine that the moment occurs fault.

Below in conjunction with specific embodiment, a kind of electric network fault recognition methods based on three-phase voltage signal provided by the invention and system are elaborated.In this specific embodiment, the sampling period is that the three-phase voltage signal of Δ t=0.1ms is as follows:

Cycle set in advance is set to T=20ms, then a cycle single-phase voltage data volume is 200.For A phase voltage:

T=t time initial₄₀₀；

Time initial, the data in data1 are: u_A(t₂₀₁)、u_A(t₂₀₂)、u_A(t₂₀₃)、…、u_A(t₄₀₀)。

Time initial, the data in data2 are: u_A(t₁)、u_A(t₂)、u_A(t₃)、…、u_A(t₂₀₀)。

Data3=| u_A(t₂₀₁)-u_A(t₁)|+|u_A(t₂₀₂)-u_A(t₂)|+…+|u_A(t₄₀₀)-u_A(t₂₀₀)|。

Judge that whether data3 is little of threshold epsilon.

(1) if data3 is not more than threshold value,

T=t₄₀₀+ Δ t=t₄₀₁；

Because t₄₀₁<t_n；

Data in data1 are: u_A(t₂₀₂)、u_A(t₂₀₃)、u_A(t₂₀₄)、…、u_A(t₄₀₁)；

Data in data2 are: u_A(t₂)、u_A(t₃)、u_A(t₄)、…、u_A(t₂₀₁)；

Now calculating data3 is then following formula:

Data3=| u_A(t₂₀₂)-u_A(t₂)|+|u_A(t₂₀₃)-u_A(t₃)|+…+|u_A(t₄₀₁)-u_A(t₂₀₁)|。

Jumping to and judge that whether data3 is little of threshold epsilon, in this embodiment, the threshold value of data3 can be 0.4～0.5 biquadratic being multiplied by 10.

(2) assume that data3 first time is more than threshold value as t=tm1

Now,

Data in data1 are: u_A(tm1-199Δt)、u_A(tm1-198Δt)、u_A(tm1-179Δt、…、u_A(tm1)；

Data in data2 are: u_A(tm1-399Δt)、u_A(tm1-398Δt)、u_A(tm1-397Δt)、…、u_A(tm1-200Δt)；

If in data1, the moment of last number, more than tn, terminates in whole process.

Utilize same method can obtain ta1, tb1, tc1, then overall fault start time T1=min (ta1, tb1, tc1).

If ta1 and tb1 approximately equal, ta1 and tb1 is significantly less than tc1, then fault type is C phase short trouble；

If tb1 and tc1 approximately equal, tb1 and tc1 is significantly less than ta1, then fault type is A phase short trouble；

If tc1 and ta1 approximately equal, tc1 and ta1 is significantly less than tb1, then fault type is B phase short trouble；

A phase short trouble, B phase short trouble, C phase short trouble is referred to as single-phase earthing fault.

If ta1 and tb1 approximately equal, ta1 and tb1 is significantly greater than tc1, then fault type is AB two-phase short-circuit fault；

If tb1 and tc1 approximately equal, tb1 and tc1 is significantly greater than ta1, then fault type is BC two-phase short-circuit fault；

If tc1 and ta1 approximately equal, tc1 and ta1 is significantly greater than tb1, then fault type is CA two-phase short-circuit fault；

AB two-phase short-circuit fault, BC two-phase short-circuit fault, CA two-phase short-circuit fault is referred to as two-phase short-circuit fault.

If ta1, tb1, tc1 three's approximately equal, then fault type is ABC three phase short circuit fault.

In sum, embodiments provide a kind of electric network fault recognition methods based on three-phase voltage signal and system, by the three-phase voltage instantaneous signal sequence of blower fan outfan bus during collection short circuit malfunction, determine fault start time, and then the fault type of short circuit malfunction can be determined according to fault start time, present invention achieves and accurately judge short circuit malfunction type, and can accurately determine that the moment occurs fault.

One of ordinary skill in the art will appreciate that all or part of flow process realizing in above-described embodiment method, can be completed by the hardware that computer program carrys out instruction relevant, described program can be stored in general computer read/write memory medium, this program is upon execution, it may include such as the flow process of the embodiment of above-mentioned each side method.Wherein, described storage medium can be magnetic disc, CD, read-only store-memory body (Read-OnlyMemory, ROM) or random store-memory body (RandomAccessMemory, RAM) etc..

Those skilled in the art are it will also be appreciated that the various functions that the embodiment of the present invention is listed are to realize depending on the designing requirement of specific application and whole system by hardware or software.Those skilled in the art can for every kind of specific application, it is possible to use various methods realize described function, but this realization is understood not to exceed the scope of embodiment of the present invention protection.

Applying specific embodiment in the present invention principles of the invention and embodiment are set forth, the explanation of above example is only intended to help to understand method and the core concept thereof of the present invention；Simultaneously for one of ordinary skill in the art, according to the thought of the present invention, all will change in specific embodiments and applications, in sum, this specification content should not be construed as limitation of the present invention.

Claims

1. the electric network fault recognition methods based on three-phase voltage signal, it is characterised in that described method includes:

The three-phase voltage instantaneous signal sequence of blower fan outfan bus during collection short circuit malfunction；

Fault start time is determined according to described three-phase voltage instantaneous signal sequence；

The fault type of described short circuit malfunction is determined according to described fault start time.

2. method according to claim 1, it is characterized in that, refer to during described short circuit malfunction fan outlet place occur short circuit malfunction or fan outlet place carry out the fault of low voltage crossing experimental simulation short circuit malfunction occur before, during fault and after failure removal until before voltage x current recovers fault.

3. method according to claim 2, it is characterised in that determine that fault start time includes according to described three-phase voltage instantaneous signal sequence:

Obtain cycle set in advance and moment；

Integrated value corresponding to described moment is determined according to described three-phase voltage instantaneous signal sequence；

Obtain integral threshold set in advance and absolute value threshold value；

When the described moment, corresponding integrated value was more than described integral threshold, obtain set in advance group of number；

Determine the several adjacent moment of group in described moment；

The described group of each self-corresponding absolute value of several adjacent moment is determined according to described three-phase voltage instantaneous signal sequence；

When the described group of each self-corresponding absolute value of several adjacent moment is all higher than described absolute value threshold value, the described moment is fault start time.

4. method according to claim 3, it is characterised in that determine that integrated value corresponding to described moment includes according to described three-phase voltage instantaneous signal sequence:

Selecting the described moment from described three-phase voltage instantaneous signal sequence is referred to as period 1 sequence to the three-phase voltage instantaneous signal sequence in the previous cycle；

The three-phase voltage instantaneous signal sequence selected in the described period 1 sequence previous cycle from described three-phase voltage instantaneous signal sequence is referred to as sequence second round；

Determine the absolute value of difference of described period 1 sequence and sequence second round；

Described absolute value is integrated within the described cycle, obtains integrated value corresponding to described moment.

5. method according to claim 3, it is characterised in that determine that the described group of each self-corresponding absolute value of several adjacent moment includes according to described three-phase voltage instantaneous signal sequence:

From described three-phase voltage instantaneous signal sequence, select described adjacent moment be referred to as first group of periodic sequence to the three-phase voltage instantaneous signal sequence in the previous cycle；

The three-phase voltage instantaneous signal sequence selected from described three-phase voltage instantaneous signal sequence in described first group of periodic sequence previous cycle is referred to as second group of periodic sequence；

Determine the absolute value of described first group of periodic sequence and the difference of second group of periodic sequence.

6. the method according to claim 4 or 5, it is characterised in that determine that the fault type of described short circuit malfunction includes according to described fault start time:

A phase fault start time, B phase fault start time and C phase fault start time is determined from described fault start time；

Obtain first threshold set in advance；

Determine described A phase fault start time, B phase fault start time and C phase fault start time difference between two respectively；

Determine the absolute value of described difference；

When the absolute value of described difference is respectively less than described first threshold, the fault type of described short circuit malfunction is three-phase shortcircuit.

7. the method according to claim 4 or 5, it is characterised in that determine that the fault type of described short circuit malfunction includes according to described fault start time:

Obtain first threshold set in advance and Second Threshold；

Determine the difference of described A phase fault start time and B phase fault start time, be called the first difference；

Determine the difference of described A phase fault start time and C phase fault start time, be called the second difference；

Determine the difference of described B phase fault start time and C phase fault start time, be called the 3rd difference；

When the absolute value of described first difference less than described first threshold, described second difference for negative and its absolute value more than described Second Threshold, described 3rd difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is C phase short trouble.

8. method according to claim 7, it is characterised in that determine that the fault type of described short circuit malfunction also includes according to described fault start time:

When described 3rd difference absolute value less than described first threshold, described first difference be just and its absolute value more than described Second Threshold, described second difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is A phase short trouble.

9. method according to claim 7, it is characterised in that determine that the fault type of described short circuit malfunction also includes according to described fault start time:

When described second difference absolute value less than described first threshold, described 3rd difference be just and its absolute value more than described Second Threshold, described first difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is B phase short trouble.

10. method according to claim 7, it is characterised in that determine that the fault type of described short circuit malfunction also includes according to described fault start time:

When described first difference absolute value less than described first threshold, described second difference be just and its absolute value more than described Second Threshold, described 3rd difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is AB phase short trouble.

11. method according to claim 7, it is characterised in that determine that the fault type of described short circuit malfunction also includes according to described fault start time:

When the absolute value of described 3rd difference less than described first threshold, described first difference for negative and its absolute value more than described Second Threshold, described second difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is BC phase short trouble.

12. method according to claim 7, it is characterised in that determine that the fault type of described short circuit malfunction also includes according to described fault start time:

When the absolute value of described second difference less than described first threshold, described 3rd difference for negative and its absolute value more than described Second Threshold, described first difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is CA phase short trouble.

13. the electric network fault identification system based on three-phase voltage signal, it is characterised in that described system includes:

Instantaneous signal harvester, for gathering the three-phase voltage instantaneous signal sequence of blower fan outfan bus during short circuit malfunction；

Fault start time determines device, for determining fault start time according to described three-phase voltage instantaneous signal sequence；

Fault type determines device, for determining the fault type of described short circuit malfunction according to described fault start time.

14. system according to claim 13, it is characterized in that, refer to during described short circuit malfunction fan outlet place occur short circuit malfunction or fan outlet place carry out the fault of low voltage crossing experimental simulation short circuit malfunction occur before, during fault and after failure removal until before voltage x current recovers fault.

15. system according to claim 13, it is characterised in that described fault start time determines that device includes:

Cycle acquisition module, is used for obtaining cycle set in advance and moment；

Integrated value determines module, for determining integrated value corresponding to described moment according to described three-phase voltage instantaneous signal sequence；

Integral threshold module, is used for obtaining integral threshold set in advance and absolute value threshold value；

Group number acquisition module, for when the described moment, corresponding integrated value was more than described integral threshold, obtaining set in advance group of number；

Adjacent moment determines module, for determining the several adjacent moment of group in described moment；

Absolute value determines module, for determining the described group of each self-corresponding absolute value of several adjacent moment according to described three-phase voltage instantaneous signal sequence；

Fault start time determines module, and for when the described group of each self-corresponding absolute value of several adjacent moment is all higher than described absolute value threshold value, the described moment is fault start time.

16. system according to claim 15, it is characterised in that described integrated value determines that module includes:

Period 1 sequence chooses unit, is referred to as period 1 sequence for selecting the described moment from described three-phase voltage instantaneous signal sequence to the three-phase voltage instantaneous signal sequence in the previous cycle；

Second round, sequence chose unit, was referred to as sequence second round for the three-phase voltage instantaneous signal sequence selected in the described period 1 sequence previous cycle from described three-phase voltage instantaneous signal sequence；

First absolute value determination unit, for determining the absolute value of difference of described period 1 sequence and sequence second round；

Integrated value determines unit, for described absolute value is integrated within the described cycle, obtains integrated value corresponding to described moment.

17. system according to claim 15, it is characterised in that described absolute value determines that module includes:

First group of periodic sequence chooses unit, is referred to as first group of periodic sequence for selecting described adjacent moment from described three-phase voltage instantaneous signal sequence to the three-phase voltage instantaneous signal sequence in the previous cycle；

Second group of periodic sequence chooses unit, is referred to as second group of periodic sequence for the three-phase voltage instantaneous signal sequence selected from described three-phase voltage instantaneous signal sequence in described first group of periodic sequence previous cycle；

Absolute value determination unit, for determining the absolute value of described first group of periodic sequence and the difference of second group of periodic sequence.

18. the system according to claim 16 or 17, it is characterised in that described fault type determines that device includes:

Fault start time determines module, for determining A phase fault start time, B phase fault start time and C phase fault start time from described fault start time；

First threshold acquisition module, is used for obtaining first threshold set in advance；

Difference determines module between two, for determining described A phase fault start time, B phase fault start time and C phase fault start time difference between two respectively；

Absolute value determines module, for determining the absolute value of described difference；

Fisrt fault determination type module, for when the absolute value of described difference is respectively less than described first threshold, the fault type of described short circuit malfunction is three-phase shortcircuit.

19. system according to claim 18, it is characterised in that described fault type determines that device also includes:

Second Threshold acquisition module, is used for obtaining Second Threshold set in advance；

First difference determines module, for determining the difference of described A phase fault start time and B phase fault start time, is called the first difference；

Second difference determines module, for determining the difference of described A phase fault start time and C phase fault start time, is called the second difference；

3rd difference determines module, for determining the difference of described B phase fault start time and C phase fault start time, is called the 3rd difference；

Second fault type determines module, for the absolute value when described first difference less than described first threshold, described second difference for negative and its absolute value more than described Second Threshold, described 3rd difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is C phase short trouble.

20. system according to claim 18, it is characterised in that described fault type determines that device also includes:

3rd fault type determines module, for when the absolute value of described 3rd difference less than described first threshold, described first difference be just and its absolute value more than described Second Threshold, described second difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is A phase short trouble.

21. system according to claim 18, it is characterised in that described fault type determines that device also includes:

4th fault type determines module, for when the absolute value of described second difference less than described first threshold, described 3rd difference be just and its absolute value more than described Second Threshold, described first difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is B phase short trouble.

22. system according to claim 18, it is characterised in that described fault type determines that device also includes:

5th fault type determines module, for when the absolute value of described first difference less than described first threshold, described second difference be just and its absolute value more than described Second Threshold, described 3rd difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is AB phase short trouble.

23. system according to claim 18, it is characterised in that described fault type determines that device also includes:

6th fault type determines module, for the absolute value when described 3rd difference less than described first threshold, described first difference for negative and its absolute value more than described Second Threshold, described second difference for negative and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is BC phase short trouble.

24. system according to claim 18, it is characterised in that described fault type determines that device also includes:

7th fault type determines module, for the absolute value when described second difference less than described first threshold, described 3rd difference for negative and its absolute value more than described Second Threshold, described first difference be just and its absolute value more than described Second Threshold time, the fault type of described short circuit malfunction is CA phase short trouble.