CN105785224B

CN105785224B - Electric network fault recognition methods and system based on three-phase voltage signal

Info

Publication number: CN105785224B
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: 2018-12-18
Anticipated expiration: 2034-12-18
Also published as: CN105785224A

Abstract

The present invention provides a kind of electric network fault recognition methods and system based on three-phase voltage signal, which comprises the three-phase voltage instantaneous signal sequence of blower output end bus during acquisition short circuit malfunction；Failure start time is determined according to the three-phase voltage instantaneous signal sequence；The fault type of the short circuit malfunction is determined according to the failure start time.The three-phase voltage instantaneous signal sequence that the present invention passes through blower output end bus during acquisition short circuit malfunction, determination is out of order start time, and then the fault type of short circuit malfunction can be determined according to failure start time, accurate judgement short circuit malfunction type is realized, and can accurately determine that the moment occurs for failure.

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 technology of wind-power electricity generation in electric system Field is concretely a kind of electric network fault recognition methods and system based on three-phase voltage signal.

Background technique

In recent years, China's installed capacity of wind-driven power was stepped up.With the conventional power generations mode phase such as hydroelectric generation, thermal power generation Than the most fundamental difference of wind-power electricity generation is the randomness, intermittence and uncontrollability of its active power output.With wind-power electricity generation In the fast development in China, installed capacity of wind-driven power rises technology year by year, and wind-power electricity generation accounts for power supply specific gravity rapid development.

After power grid failure leads to Voltage Drop, if the numerous and confused off-the-line of Wind turbine, can bring network system transient state Unstable, and may cause is locally even that system is paralysed comprehensively, it is grid-connected and accordingly propose low that old friends begin to focus on blower Voltage ride-through (LVRT) requirement, it is desirable that the blower of domestic all models will carry out low voltage crossing test before grid-connected.

So-called low voltage crossing test refers to that manual simulation's power grid occurs short trouble and causes the grid-connected place's Voltage Drop of blower, Failure is cut off after specific time makes the process that voltage is gradually recovered, to examine the test of blower low voltage ride-through capability.? Three-phase voltage and three-phase current at real-time measurement fan outlet are understood in low voltage crossing test process.By analyzing surveyed voltage electricity Stream signal not only can analyze the low voltage crossing characteristic of blower, moreover it is possible to recognize to the parameter of wind-driven generator.

Therefore, this field is badly in need of wanting a kind of electric network fault identifying schemes based on three-phase voltage signal, can determine electricity Which kind of failure occurs for net, at the time of determination is broken down and at the time of failure removal, at progress subsequent parameter Identification Data The basis of reason.

Summary of the invention

In order to solve above-mentioned technological deficiency of the existing technology, the embodiment of the invention provides one kind to be based on three-phase voltage The electric network fault recognition methods of signal and system pass through the three-phase electricity of blower output end bus during acquisition short circuit malfunction Instantaneous signal sequence is pressed, determination is out of order start time, and then can determine short circuit malfunction according to failure start time Fault type, the present invention realize accurate judgement short circuit malfunction type, and can accurately determine that the moment occurs for failure.

The electric network fault recognition methods based on three-phase voltage signal that it is an object of the invention to provide a kind of, it is described Method includes: the three-phase voltage instantaneous signal sequence of blower output end bus during acquiring short circuit malfunction；According to described Three-phase voltage instantaneous signal sequence determines failure start time；The short circuit malfunction is determined according to the failure start time Fault type.

In a preferred embodiment of the invention, refer to during the short circuit malfunction and electricity occurs at fan outlet Network short circuit fault or the failure that low voltage crossing experiment simulating grid short trouble is carried out at the fan outlet occur before, age at failure Between and failure removal after until voltage and current restore failure before.

In a preferred embodiment of the invention, when determining that failure starts according to the three-phase voltage instantaneous signal sequence Quarter includes: to obtain preset period and moment；The moment is determined according to the three-phase voltage instantaneous signal sequence Corresponding integrated value；Obtain preset integral threshold and absolute value threshold value；When the moment corresponding integrated value is greater than When the integral threshold, preset group of number is obtained；Determine the several adjacent moments of the group at the moment；According to the three-phase Voltage transient signal sequence determines described group of several corresponding absolute value of adjacent moment；When described group of several adjacent moments are each When self-corresponding absolute value is all larger than the absolute value threshold value, the moment is failure start time.

In a preferred embodiment of the invention, the moment pair is determined according to the three-phase voltage instantaneous signal sequence The integrated value answered includes: to select three-phase of the moment into previous cycle from the three-phase voltage instantaneous signal sequence Voltage transient signal sequence is referred to as period 1 sequence；Described is selected from the three-phase voltage instantaneous signal sequence Three-phase voltage instantaneous signal sequence in one periodic sequence previous cycle is referred to as second round sequence；Determine the period 1 The absolute value of the difference of sequence and second round sequence；The absolute value is integrated within the period, obtains the moment Corresponding integrated value.

In a preferred embodiment of the invention, according to the three-phase voltage instantaneous signal sequence determine described group it is several The corresponding integrated value of adjacent moment includes: to select the adjacent moment from the three-phase voltage instantaneous signal sequence Three-phase voltage instantaneous signal sequence into previous cycle is referred to as first group of periodic sequence；Instantaneously believe from the three-phase voltage The three-phase voltage instantaneous signal sequence in first group of periodic sequence previous cycle is selected in number sequence is referred to as second group of week Phase sequence；Determine the absolute value of the difference of first group of periodic sequence and second group of periodic sequence.

In a preferred embodiment of the invention, the event of the short circuit malfunction is determined according to the failure start time Hindering type includes: that A phase fault start time, B phase fault start time and C phase are determined from the failure start time Failure start time；Obtain preset first threshold；Determine that the A phase fault start time, B phase fault start respectively The difference of moment and C phase fault start time two-by-two；Determine the absolute value of the difference；When the absolute value of the difference is small When the first threshold, the fault type of the short circuit malfunction is three-phase shortcircuit.

In a preferred embodiment of the invention, the event of the short circuit malfunction is determined according to the failure start time Hindering type includes: that A phase fault start time, B phase fault start time and C phase are determined from the failure start time Failure start time；Obtain preset first threshold and second threshold；Determine the A phase fault start time and B The difference of phase fault start time, referred to as the first difference；Determine the A phase fault start time and C phase fault start time Difference, referred to as the second difference；Determine the difference of the B phase fault start time and C phase fault start time, referred to as third Difference；When the absolute value of first difference is less than the first threshold, second difference is negative and its absolute value is greater than institute Second threshold is stated, when the third difference is negative and its absolute value is greater than the second threshold, the event of the short circuit malfunction Barrier type is C phase short trouble.

In a preferred embodiment of the invention, the event of the short circuit malfunction is determined according to the failure start time Hinder type further include: when the absolute value of the third difference is less than the first threshold, first difference is positive and it is absolute Value is greater than the second threshold, when second difference is positive and its absolute value is greater than the second threshold, the grid short circuit The fault type of failure is A phase short trouble.

In a preferred embodiment of the invention, the event of the short circuit malfunction is determined according to the failure start time Hinder type further include: when the absolute value of second difference is less than the first threshold, the third difference is positive and it is absolute Value is greater than the second threshold, when first difference is negative and its absolute value is greater than the second threshold, the grid short circuit The fault type of failure is B phase short trouble.

In a preferred embodiment of the invention, the event of the short circuit malfunction is determined according to the failure start time Hinder type further include: when the absolute value of first difference is less than the first threshold, second difference is positive and it is absolute Value is greater than the second threshold, when the third difference is positive and its absolute value is greater than the second threshold, the grid short circuit The fault type of failure is AB phase short trouble.

In a preferred embodiment of the invention, the event of the short circuit malfunction is determined according to the failure start time Hinder type further include: when the absolute value of the third difference is less than the first threshold, first difference is negative and it is absolute Value is greater than the second threshold, when second difference is negative and its absolute value is greater than the second threshold, the grid short circuit The fault type of failure is BC phase short trouble.

In a preferred embodiment of the invention, the event of the short circuit malfunction is determined according to the failure start time Hinder type further include: when the absolute value of second difference is less than the first threshold, the third difference is negative and it is absolute Value is greater than the second threshold, when first difference is positive and its absolute value is greater than the second threshold, the grid short circuit The fault type of failure is CA phase short trouble.

The electric network fault identifying system based on three-phase voltage signal that it is an object of the invention to provide a kind of, it is described System includes: instantaneous signal acquisition device, the three-phase voltage wink for blower output end bus during acquiring short circuit malfunction When signal sequence；Failure start time determining device, for determining that failure is opened according to the three-phase voltage instantaneous signal sequence Begin the moment；Fault type determining device, for determining the failure classes of the short circuit malfunction according to the failure start time Type.

In a preferred embodiment of the invention, the failure start time determining device includes: to obtain module in the period, For obtaining preset period and moment；Integrated value determining module, for according to the three-phase voltage instantaneous signal Sequence determines the moment corresponding integrated value；Integral threshold module, for obtain preset integral threshold and absolutely It is worth threshold value；Group number obtains module, for when the moment corresponding integrated value is greater than the integral threshold, acquisition to be preset Group number；Adjacent moment determining module, the several adjacent moments of group for determining the moment；Absolute value determining module, is used for Described group of several corresponding absolute value of adjacent moment is determined according to the three-phase voltage instantaneous signal sequence；Failure starts Moment determining module, for when described group of several corresponding absolute values of adjacent moment are all larger than the absolute value threshold value, The moment is failure start time.

In a preferred embodiment of the invention, the integrated value determining module includes: that period 1 sequence chooses list Member, it is instantaneous for selecting three-phase voltage of the moment into previous cycle from the three-phase voltage instantaneous signal sequence Signal sequence is referred to as period 1 sequence；Second round sequence selection unit, for from the three-phase voltage instantaneous signal The three-phase voltage instantaneous signal sequence selected in the period 1 sequence previous cycle in sequence is referred to as second round sequence Column；First absolute value determination unit, for determining the absolute value of the difference of the period 1 sequence and second round sequence；Integral It is worth determination unit and obtains the moment corresponding integrated value for integrating within the period to the absolute value.

In a preferred embodiment of the invention, the absolute value determining module includes: that first group of periodic sequence is chosen Unit, for selecting three-phase electricity of the adjacent moment into previous cycle from the three-phase voltage instantaneous signal sequence Pressure instantaneous signal sequence is referred to as first group of periodic sequence；Second group of periodic sequence selection unit, for from the three-phase electricity The three-phase voltage instantaneous signal sequence selected in first group of periodic sequence previous cycle in pressure instantaneous signal sequence is referred to as Second group of periodic sequence；Second absolute value determination unit, for determining first group of periodic sequence and second group of periodic sequence Absolute value of the difference.

In a preferred embodiment of the invention, the fault type determining device includes: and determines failure start time Module, for determining A phase fault start time, B phase fault start time and the event of C phase from the failure start time Hinder start time；First threshold obtains module, for obtaining preset first threshold；Difference determining module two-by-two is used for The A phase fault start time, the difference of B phase fault start time and C phase fault start time two-by-two are determined respectively；Absolutely To value determining module, for determining the absolute value of the difference；Fisrt fault determination type module, for working as the exhausted of the difference When being respectively less than the first threshold to value, the fault type of the short circuit malfunction is three-phase shortcircuit.

In a preferred embodiment of the invention, the fault type determining device further include: second threshold obtains mould Block, for obtaining preset second threshold；First difference determining module, for determining the A phase fault start time With the difference of B phase fault start time, referred to as the first difference；Second difference determining module, the A phase fault for determining described are opened The difference at beginning moment and C phase fault start time, referred to as the second difference；Third difference determining module, for determining the B phase The difference of failure start time and C phase fault start time, referred to as third difference；Second fault type determining module, for working as The absolute value of first difference is less than the first threshold, second difference is negative and its absolute value is greater than second threshold Value, when the third difference is negative and its absolute value is greater than the second threshold, the fault type of the short circuit malfunction is C Phase short trouble.

In a preferred embodiment of the invention, the fault type determining device further include: third fault type is true Cover half block, for when the third difference absolute value be less than the first threshold, first difference is positive and its absolute value Greater than the second threshold, when second difference is positive and its absolute value is greater than the second threshold, the grid short circuit event The fault type of barrier is A phase short trouble.

In a preferred embodiment of the invention, the fault type determining device further include: the 4th fault type is true Cover half block, for when second difference absolute value be less than the first threshold, the third difference is positive and its absolute value Greater than the second threshold, when first difference is negative and its absolute value is greater than the second threshold, the grid short circuit event The fault type of barrier is B phase short trouble.

In a preferred embodiment of the invention, the fault type determining device further include: the 5th fault type is true Cover half block, for when first difference absolute value be less than the first threshold, second difference is positive and its absolute value Greater than the second threshold, when the third difference is positive and its absolute value is greater than the second threshold, the grid short circuit event The fault type of barrier is AB phase short trouble.

In a preferred embodiment of the invention, the fault type determining device further include: the 6th fault type is true Cover half block, for when the third difference absolute value be less than the first threshold, first difference is negative and its absolute value Greater than the second threshold, when second difference is negative and its absolute value is greater than the second threshold, the grid short circuit event The fault type of barrier is BC phase short trouble.

In a preferred embodiment of the invention, the fault type determining device further include: the 7th fault type is true Cover half block, for when second difference absolute value be less than the first threshold, the third difference is negative and its absolute value Greater than the second threshold, when first difference is positive and its absolute value is greater than the second threshold, the grid short circuit event The fault type of barrier is CA phase short trouble.

The beneficial effects of the present invention are, 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 output end bus during acquisition short circuit malfunction, determination is out of order Start time, and then the fault type of short circuit malfunction can be determined according to failure start time, the present invention realizes accurately Judge short circuit malfunction type, and can accurately determine that the moment occurs for failure.

For above and other objects, features and advantages of the invention can be clearer and more comprehensible, preferred embodiment is cited below particularly, And cooperate institute's accompanying drawings, it is described in detail below.

Detailed description of the invention

In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this Some embodiments of invention for those of ordinary skill in the art without creative efforts, can be with It obtains other drawings based on these drawings.

Fig. 1 is that a kind of process of the electric network fault recognition methods based on three-phase voltage signal provided in an embodiment of the present invention is shown It is intended to；

Fig. 2 is the specific flow chart of the step S102 in Fig. 1；

Fig. 3 is the specific flow chart of the step S202 in Fig. 2；

Fig. 4 is the specific flow chart of the step S206 in Fig. 2；

Fig. 5 is the specific flow chart of the embodiment one of the step S103 in Fig. 1；

Fig. 6 is the specific flow chart of the embodiment two of the step S103 in Fig. 1；

Fig. 7 is the specific flow chart of the embodiment three of the step S103 in Fig. 1；

Fig. 8 is the specific flow chart of the embodiment four of the step S103 in Fig. 1；

Fig. 9 is the specific flow chart of the embodiment five of the step S103 in Fig. 1；

Figure 10 is the specific flow chart of the embodiment six of the step S103 in Fig. 1；

Figure 11 is the specific flow chart of the embodiment seven of the step S103 in Fig. 1；

Figure 12 is a kind of structure of the electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention Block diagram；

Figure 13 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of start time determining device；

Figure 14 is to integrate in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention It is worth the structural block diagram of determining module；

Figure 15 is absolute in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention It is worth the structural block diagram of determining module；

Figure 16 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment one of type determination device；

Figure 17 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment two of type determination device；

Figure 18 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment three of type determination device；

Figure 19 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment four of type determination device；

Figure 20 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment five of type determination device；

Figure 21 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment six of type determination device；

Figure 22 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment seven of type determination device；

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 voltage change figure in specific embodiment in whole experiment process；

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

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

Specific embodiment

Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts every other Embodiment shall fall within the protection scope of the present invention.

Most primary task is which kind of failure occurs for determining power grid before to many specificity analysis of wind energy conversion system, followed by determines At the time of breaking down and at the time of failure removal.This two tasks are to carry out the basis of subsequent parameter Identification Data Processing.

The method currently generally used is to seek the virtual value of every voltage first, then recognize when voltage effective value falls For short trouble occurs, fall degree by comparing each phase voltage virtual value, to judge the type of short trouble.It is specific former It manages as follows:

In blower low voltage crossing test process, fan outlet terminal voltage signal can undergo following three stable state: A. Voltage normal condition, B. malfunction, C. voltage normal condition.In voltage from A condition to having about 0.1 when B state transition Second complicated transient process, 0.01 second transient process is had when from B state to C process transitions.In Figure 23, Figure 24, Figure 25 Shown in faulted phase voltage variation diagram one, faulted phase voltage variation diagram two, in faulted phase voltage variation diagram three, when A condition refers to t1 Before quarter, after B state refers to that t2 to t3, C-state refer to t4.

By taking A phase as an example, A phase voltage is under normal circumstances

Wherein, Um is amplitude, f=50Hz.

Voltage effective value calculation formula is

When voltage is normal

Voltage effective value can also be sought with following formula known to the characteristics of SIN function by having

When voltage is normal

The voltage signal measured in practice is discrete point, before failure generation, during failure and after failure removal Until voltage and current restores pre-fault status every Δ t (Δ t should meet Δ t < 0.005s) time, blower output is acquired in real time Hold the three-phase voltage instantaneous signal sequential value of 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_nAt the time of respectively indicating acquisition each electric signal, successively time interval is Δ t.

It is by the formula of the voltage effective value at (2) formula calculating t0 moment at this time

Wherein, t1=t0-T/2, t2=t0+T/2, T are the period of voltage.

It is by the formula of the voltage effective value at (4) formula calculating t0 moment at this time

Wherein, t1=t0-T/4, t2=t0+T/4, T are the period of voltage

T0 moment A phase voltage virtual value is named as to (6) formula calculated result in the present invention, (7) formula calculated result is then ordered Entitled t0 moment A phase voltage half-wave virtual value.

Figure 26, Figure 27, Figure 28 show the instantaneous voltage curve of measurement, half-wave virtual value curve, virtual value curve And by the instantaneous voltage image of measurement to the constitutional diagram of right translation a cycle curve obtained.

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

(1) time (virtual value method hereinafter) to judge failure generation or excision is increasedd or decreased by virtual value, Error is 0~0.5 cycle, i.e. 0~0.01s.

(2) (half-wave has hereinafter at the time of increaseing or decreasing to judge that failure occurs or cuts off by half-wave virtual value Valid value method), error is 0~0.25 cycle, i.e. 0~0.005s.

(3) judge by comparing the difference of this period instantaneous voltage and a upper periodic voltage instantaneous value failure occur or At the time of person cuts off (curve compares religious name word and can restart hereinafter), if threshold value selection is suitable, error can be reduced to 2 Δs The Δ of t~10 t (Δ t is the sampling period).

When the core concept of curve comparison method: by instantaneous voltage curve with by instantaneous voltage curve to right translation one Period curve obtained is compared, when two curves persistently have relatively large deviation for the first time, then it is assumed that be when just beginning with deviation Failure start time.Judgement is out of order the complicated transient state mistake avoided after start time between voltage normal condition and malfunction Journey starts again at from stable malfunction and compares two curves, when two curves persistently have relatively large deviation again, then it is assumed that It is the failure removal moment when just beginning with deviation.

Two above-mentioned curves were relatively equivalent to the instantaneous voltage in this period compared with the instantaneous voltage in a upper period Compared with.Two above-mentioned curve deviations can be characterized with the integral of instantaneous voltage absolute value of the difference in two periods, when this product Score value (being equivalent to the area between two lines) then thinks that failure occurred within this period when being greater than a certain threshold value.To two periods Instantaneous voltage on same phase makees difference and takes absolute value to make comparisons with the threshold value of setting, when some data difference it is absolute Value is more than after threshold value, and the absolute value of the difference of several data continues to exceed threshold value later, then it is assumed that when first data is corresponding Carve is fault moment to be determined or failure removal moment.

Influence due to failure with respect to non-faulting phase has a small delay, therefore can be according to the elder generation of each fault moment Fault type is judged later.When the fault moment of a certain phase is obviously earlier than the fault moment of other two-phases, and in addition two-phase Fault moment is close, it may be considered that single-phase short circuit has occurred；When the fault moment of a certain phase is obviously later than the event of other two-phases Hinder the moment, and the fault moment of other two-phase is close, it may be considered that line to line fault has occurred；When the fault moment of three-phase is equal When similar, it may be considered that three-phase shortcircuit has occurred.

Virtual value method described in above-mentioned principal portion and half-wave virtual value method can be realized the judgement and failure of fault moment The judgement of type.But judge computationally intensive when fault moment, and bigger error.

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

Fig. 1 is that a kind of process of the electric network fault recognition methods based on three-phase voltage signal provided in an embodiment of the present invention is shown It is intended to, as shown in Figure 1, this method comprises:

S101: the three-phase voltage instantaneous signal sequence of blower output end bus during acquisition short circuit malfunction.Described Refer to during short circuit malfunction and short circuit malfunction or the progress low voltage crossing at fan outlet occur at fan outlet Test simulating grid short trouble failure occur before, during failure and after failure removal until voltage and current restores failure Before.

In a particular embodiment, three-phase voltage instantaneous signal sequence refers to the generation short circuit malfunction at fan outlet Or when carrying out simulating grid short trouble when low voltage crossing experiment, before failure generation, during failure and failure removal Afterwards until voltage and current restores pre-fault status every Δ t (Δ t should meet Δ t < 0.005s) time, it is defeated that blower is acquired in real time The three-phase voltage instantaneous signal sequential value of outlet bus, sampling period are that the three-phase voltage signal of Δ t is as follows:

S102: failure start time is determined according to the three-phase voltage instantaneous signal sequence.

S103: the fault type of the short circuit malfunction is determined according to the failure start time.

Because either single-phase short circuit or line to line fault occur for power grid, not breaking down mutually also will appear voltage fluctuation, Non-faulting phase fault is defined herein occur moment and failure removal moment refer at the time of influenced by failure and voltage fluctuation occurs.Figure 2 be the specific flow chart of the step S102 in Fig. 1, and as shown in Figure 2, step S102 includes:

S201: preset period and moment are obtained.

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

S202: the moment corresponding integrated value is determined according to the three-phase voltage instantaneous signal sequence.Fig. 3 is step The specific flow chart of S202, in a particular embodiment, moment corresponding integrated value are data3.From the figure 3, it may be seen that step Suddenly S202 includes:

S301: three-phase electricity of the moment into previous cycle is selected from the three-phase voltage instantaneous signal sequence Pressure instantaneous signal sequence is referred to as period 1 sequence；

In a particular embodiment, if the period is T=20ms, moment t, the sampling period is Δ t=0.1ms.Then from Three-phase voltage instantaneous signal sequence, that is, period 1 sequence of the t moment into previous cycle is obtained in three-phase voltage instantaneous signal sequence Arrange data1.

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

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

Since each t only increases Δ t, thus actually data1 and data2 only abandoned when updating it is earliest in the respective period In addition one voltage data increases the corresponding voltage data of t moment instantly.So in data with being newly to use to keep other Data do not change, only delete data and increase a data, improve program operational efficiency with this.

S303: the absolute value of the difference of the period 1 sequence and second round sequence is determined；

S304: the absolute value is integrated within the period, obtains the moment corresponding integrated value.

In a particular embodiment, i.e., pair | data1-data2 | it integrates in one cycle, integrated value data3. The practical area for characterizing folded part after curve data1 is not overlapped with data2 of data3.

Amplitude Um=563V, period T=20ms, sampling period are Δ t=0.1ms, then a cycle single-phase voltage number It is 200 according to amount.By taking A phase voltage as an example:

T=t40 when initial

Data when initial in data1 are as follows: u_A(t₂₀₁)、u_A(t₂₀₂)、u_A(t₂₀₃)、…、u_A(t₄₀₀)

Data when initial in data2 are as follows: 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 further include:

S203: obtaining preset integral threshold and absolute value threshold value, and integral threshold is set as ε, and absolute value threshold value is set For δ.

S204: when the moment corresponding integrated value is greater than the integral threshold, preset group of number is obtained.

In a particular embodiment, such as preset group of number is 6.

In a particular embodiment, when the moment corresponding integrated value is not more than the integral threshold, t adds Δ t, Continue to judge whether t is true more than or equal to end time tn, if then terminating, thens follow the steps S202 if not.

S205: the several adjacent moments of the group at the moment are determined, that is, determine 6 adjacent moments of moment t.

S206: determine that described group of several adjacent moments are corresponding absolutely according to the three-phase voltage instantaneous signal sequence To value.Fig. 4 is the specific flow chart of step S202, and as shown in Figure 4, step S206 includes:

S401: three of the adjacent moment into previous cycle are selected from the three-phase voltage instantaneous signal sequence Phase voltage instantaneous signal sequence is referred to as first group of periodic sequence；

In a particular embodiment, if the period is T=20ms, moment t, the sampling period is Δ t=0.1ms.Then from Three-phase voltage instantaneous signal sequence of the adjacent moment of t moment into previous cycle is obtained in three-phase voltage instantaneous signal sequence is First group of periodic sequence.

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

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

S403: the absolute value of the difference of first group of periodic sequence and second group of periodic sequence is determined.

As shown in Figure 2, step S102 further include:

S207: described when described group of several corresponding absolute values of adjacent moment are all larger than the absolute value threshold value Moment is failure start time.

In a particular embodiment, it is assumed that judged in step S204 as t=tm1, data3 is greater than integral for the first time Threshold epsilon, at this time:

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 failure, calculates separately the several corresponding absolute values of adjacent moment of group at this time, specifically , the absolute value that step S403 is determined 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)|。

Tb1, tc1 can be found out using same method, then whole failure start time T=min (ta1, tb1, tc1)。

Above step is determined according to the three-phase voltage instantaneous signal sequence in addition to failure start time, according to described Failure start time determines the fault type of the short circuit malfunction.Specifically, comparing what three-phase voltage signal failure started The successive time judges fault type.Influence due to failure with respect to non-faulting phase has a small delay, therefore can basis Each fault moment first judges fault type later.When the fault moment of a certain phase is obviously earlier than the fault moment of other two-phases, And the fault moment of other two-phase is close, it may be considered that single-phase short circuit has occurred；When the fault moment of a certain phase is obviously late In the fault moment of other two-phases, and the fault moment of other two-phase is close, it may be considered that line to line fault has occurred；When three When the fault moment of phase is similar, it may be considered that three-phase shortcircuit has occurred.It is introduced one by one with reference to the accompanying drawing.

Fig. 5 is the specific flow chart of the embodiment one of the step S103 in Fig. 1, and as shown in Figure 5, the step is in embodiment party It is specifically included in formula one:

S501: A phase fault start time, B phase fault start time and C are determined from the failure start time Phase fault start time.In a particular embodiment, the whole failure start time T=min determined in step S102 (ta1, tb1, tc1), therefrom extracts A phase fault start time ta1, B phase fault start time tb1 and C phase fault starts Moment tc1.

S502: obtaining preset first threshold, and in a particular embodiment, first threshold can be based on practical experience Value is preset, and such as first threshold is 1ms.

S503: A phase fault start time, B phase fault start time and the C phase fault start time are determined respectively Difference two-by-two；

S504: the absolute value of the difference is determined；

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

Fig. 6 is the specific flow chart of the embodiment two of the step S103 in Fig. 1, and the step is specific in the second embodiment Include:

S601: A phase fault start time, B phase fault start time and C are determined from the failure start time Phase fault start time.In a particular embodiment, the whole failure start time T=min determined in step S102 (ta1, tb1, tc1), therefrom extracts A phase fault start time ta1, B phase fault start time tb1 and C phase fault starts Moment tc1.

S602: obtaining preset first threshold and second threshold, in a particular embodiment, first threshold, Second threshold can be worth based on practical experience to be preset, and such as first threshold is 1ms, second threshold 2ms.

S603: the difference of the A phase fault start time and B phase fault start time, referred to as the first difference are determined；

S604: the difference of the A phase fault start time and C phase fault start time, referred to as the second difference are determined；

S605: the difference of the B phase fault start time and C phase fault start time, referred to as third difference are determined；

S606: when the absolute value of first difference is less than the first threshold, second difference is negative and it is absolute Value is greater than the second threshold, when the third difference is negative and its absolute value is greater than the second threshold, the grid short circuit The fault type of failure is C phase short trouble.

That is, in a particular embodiment, as | ta1-tb1 | be less than the first threshold, | ta1-tc1 | be greater than described Second threshold and ta1 be less than tc1, | tb1-tc1 | be greater than the second threshold and when tb1 is less than tc1, it is believed that ta1 and tb1 Approximately equal, ta1 is significantly less than tc1, and tb1 is significantly less than tc1, then the fault type of short circuit malfunction is C phase short trouble.

Fig. 7 is the specific flow chart of the embodiment three of the step S103 in Fig. 1, and the step is specific in the third embodiment Include:

S701: A phase fault start time, B phase fault start time and C are determined from the failure start time Phase fault start time.In a particular embodiment, the whole failure start time T=min determined in step S102 (ta1, tb1, tc1), therefrom extracts A phase fault start time ta1, B phase fault start time tb1 and C phase fault starts Moment tc1.

S702: obtaining preset first threshold and second threshold, in a particular embodiment, first threshold, Second threshold can be worth based on practical experience to be preset, and such as first threshold is 1ms, second threshold 2ms.

S703: the difference of the A phase fault start time and B phase fault start time, referred to as the first difference are determined；

S704: the difference of the A phase fault start time and C phase fault start time, referred to as the second difference are determined；

S705: the difference of the B phase fault start time and C phase fault start time, referred to as third difference are determined；

S706: when the absolute value of the third difference is less than the first threshold, first difference is positive and it is absolute Value is greater than the second threshold, when second difference is positive and its absolute value is greater than the second threshold, the grid short circuit The fault type of failure is A phase short trouble.

That is, in a particular embodiment, as | ta1-tb1 | be greater than the second threshold and ta1 be greater than tb1, | ta1- Tc1 | be greater than the second threshold and ta1 be greater than tc1, | tb1-tc1 | when being less than the first threshold, it is believed that tb1 and tc1 Approximately equal, tb1 is significantly less than ta1, and tc1 is significantly less than ta1, then the fault type of short circuit malfunction is A phase short trouble.

Fig. 8 is the specific flow chart of the embodiment four of the step S103 in Fig. 1, and the step is specific in the fourth embodiment Include:

S801: A phase fault start time, B phase fault start time and C are determined from the failure start time Phase fault start time.In a particular embodiment, the whole failure start time T=min determined in step S102 (ta1, tb1, tc1), therefrom extracts A phase fault start time ta1, B phase fault start time tb1 and C phase fault starts Moment tc1.

S802: obtaining preset first threshold and second threshold, in a particular embodiment, first threshold, Second threshold can be worth based on practical experience to be preset, and such as first threshold is 1ms, second threshold 2ms.

S803: the difference of the A phase fault start time and B phase fault start time, referred to as the first difference are determined；

S804: the difference of the A phase fault start time and C phase fault start time, referred to as the second difference are determined；

S805: the difference of the B phase fault start time and C phase fault start time, referred to as third difference are determined；

S806: when the absolute value of second difference is less than the first threshold, the third difference is positive and it is absolute Value is greater than the second threshold, when first difference is negative and its absolute value is greater than the second threshold, the grid short circuit The fault type of failure is B phase short trouble.

That is, in a particular embodiment, as | ta1-tb1 | be greater than the second threshold and a1 be less than tb1, | ta1- Tc1 | be less than the first threshold, | tb1-tc1 | when being greater than the second threshold and tb1 and being greater than tc1, it is believed that tc1 and ta1 Approximately equal, tc1 is significantly less than tb1, and ta1 is significantly less than tb1, then the fault type of short circuit malfunction is B phase short trouble.

Above embodiment two into embodiment four, be referred to as by A phase short trouble, B phase short trouble, C phase short trouble For single-phase earthing fault.

Fig. 9 is the specific flow chart of the embodiment five of the step S103 in Fig. 1, and the step is specific in embodiment five Include:

S901: A phase fault start time, B phase fault start time and C are determined from the failure start time Phase fault start time.In a particular embodiment, the whole failure start time T=min determined in step S102 (ta1, tb1, tc1), therefrom extracts A phase fault start time ta1, B phase fault start time tb1 and C phase fault starts Moment tc1.

S902: obtaining preset first threshold and second threshold, in a particular embodiment, first threshold, Second threshold can be worth based on practical experience to be preset, and such as first threshold is 1ms, second threshold 2ms.

S903: the difference of the A phase fault start time and B phase fault start time, referred to as the first difference are determined；

S904: the difference of the A phase fault start time and C phase fault start time, referred to as the second difference are determined；

S905: the difference of the B phase fault start time and C phase fault start time, referred to as third difference are determined；

S906: when the absolute value of first difference is less than the first threshold, second difference is positive and it is absolute Value is greater than the second threshold, when the third difference is positive and its absolute value is greater than the second threshold, the grid short circuit The fault type of failure is AB phase short trouble.

That is, in a particular embodiment, as | ta1-tb1 | be less than the first threshold, | ta1-tc1 | be greater than described Second threshold and ta1 be greater than tc1, | tb1-tc1 | be greater than the second threshold and when tb1 is greater than tc1, it is believed that ta1 and tb1 Approximately equal, ta1 is significantly greater than tc1, and tb1 is significantly greater than tc1, then the fault type of short circuit malfunction is the short circuit event of AB phase Barrier.

Figure 10 is the specific flow chart of the embodiment six of the step S103 in Fig. 1, which has in embodiment six Body includes:

S1001: determined from the failure start time A phase fault start time, B phase fault start time and C phase fault start time.In a particular embodiment, the whole failure start time T=min determined in step S102 (ta1, tb1, tc1), therefrom extracts A phase fault start time ta1, B phase fault start time tb1 and C phase fault starts Moment tc1.

S1002: obtaining preset first threshold and second threshold, in a particular embodiment, first threshold, Second threshold can be worth based on practical experience to be preset, and such as first threshold is 1ms, second threshold 2ms.

S1003: the difference of the A phase fault start time and B phase fault start time, referred to as the first difference are determined；

S1004: the difference of the A phase fault start time and C phase fault start time, referred to as the second difference are determined；

S1005: the difference of the B phase fault start time and C phase fault start time, referred to as third difference are determined；

S1006: when the absolute value of the third difference is less than the first threshold, first difference is negative and it is absolute Value is greater than the second threshold, when second difference is negative and its absolute value is greater than the second threshold, the grid short circuit The fault type of failure is BC phase short trouble.

That is, in a particular embodiment, as | ta1-tb1 | be greater than the second threshold and a1 be less than tb1, | ta1- Tc1 | be greater than the second threshold and ta1 be less than tb1, | tb1-tc1 | when being less than the first threshold, it is believed that tb1 and tc1 Approximately equal, tb1 is significantly greater than ta1, and tc1 is significantly greater than ta1, then the fault type of short circuit malfunction is the short circuit event of BC phase Barrier.

Figure 11 is the specific flow chart of the embodiment seven of the step S103 in Fig. 1, which has in embodiment seven Body includes:

S1101: determined from the failure start time A phase fault start time, B phase fault start time and C phase fault start time.In a particular embodiment, the whole failure start time T=min determined in step S102 (ta1, tb1, tc1), therefrom extracts A phase fault start time ta1, B phase fault start time tb1 and C phase fault starts Moment tc1.

S1102: obtaining preset first threshold and second threshold, in a particular embodiment, first threshold, Second threshold can be worth based on practical experience to be preset, and such as first threshold is 1ms, second threshold 2ms.

S1103: the difference of the A phase fault start time and B phase fault start time, referred to as the first difference are determined；

S1104: the difference of the A phase fault start time and C phase fault start time, referred to as the second difference are determined；

S1105: the difference of the B phase fault start time and C phase fault start time, referred to as third difference are determined；

S1106: when the absolute value of second difference is less than the first threshold, the third difference is negative and it is absolute Value is greater than the second threshold, when first difference is positive and its absolute value is greater than the second threshold, the grid short circuit The fault type of failure is CA phase short trouble.

That is, in a particular embodiment, as | ta1-tb1 | be greater than the second threshold and a1 be greater than tb1, | ta1- Tc1 | be less than the first threshold, | tb1-tc1 | when being greater than the second threshold and tb1 and being less than tc1, it is believed that tc1 and ta1 Approximately equal, tc1 is significantly greater than tb1, and ta1 is significantly greater than tb1, then the fault type of short circuit malfunction is the short circuit event of CA phase Barrier.

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

More than, it is a kind of electric network fault recognition methods based on three-phase voltage signal provided by the invention, passes through acquisition The three-phase voltage instantaneous signal sequence of blower output end bus during short circuit malfunction, determination are out of order start time, in turn The fault type of short circuit malfunction can be determined according to failure start time, the present invention realizes the event of accurate judgement grid short circuit Hinder type, and can accurately determine that the moment occurs for failure.

Figure 12 is a kind of structure of the electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention Block diagram, as shown in Figure 12, which includes:

Instantaneous signal acquisition device 101, the three-phase voltage for blower output end bus during acquiring short circuit malfunction Instantaneous signal sequence.Refer to during the short circuit malfunction and short circuit malfunction occurs at fan outlet or goes out in blower The failure that mouthful place carries out low voltage crossing experiment simulating grid short trouble occur before, during failure and after failure removal up to Before voltage and current restores failure.

Failure start time determining device 102, for determining that failure is opened according to the three-phase voltage instantaneous signal sequence Begin the moment.

Fault type determining device 103, for determining the event of the short circuit malfunction according to the failure start time Hinder type.

Because either single-phase short circuit or line to line fault occur for power grid, not breaking down mutually also will appear voltage fluctuation, Non-faulting phase fault is defined herein occur moment and failure removal moment refer at the time of influenced by failure and voltage fluctuation occurs.Figure 13 is true for failure start time in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention Determine the structural block diagram of device, as shown in Figure 13, failure start time determining device 102 includes:

Period obtains module 201, for obtaining preset period and moment.

Score value determining module 202, for determining that the moment is corresponding according to the three-phase voltage instantaneous signal sequence Integrated value.Figure 14 is integrated value in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of determining module, in a particular embodiment, moment corresponding integrated value are data3.As shown in Figure 14, Integrated value determining module 202 includes:

Period 1 sequence selection unit 301, it is described for being selected from the three-phase voltage instantaneous signal sequence Three-phase voltage instantaneous signal sequence of the moment into previous cycle is referred to as period 1 sequence；

Second round sequence selection unit 302, it is described for being selected from the three-phase voltage instantaneous signal sequence Three-phase voltage instantaneous signal sequence in period 1 sequence previous cycle is referred to as second round sequence；

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

Integrated value determination unit 304 obtains the moment pair for integrating within the period to the absolute value The integrated value answered.

T=t40 when initial

As shown in Figure 13, failure start time determining device 102 further include:

Integral threshold module 203 is set as obtaining preset integral threshold and absolute value threshold value, integral threshold ε, absolute value threshold value are set as δ.

Group number obtains module 204, for obtaining preparatory when the moment corresponding integrated value is greater than the integral threshold The group number of setting.

In a particular embodiment, such as preset group of number is 6.

Adjacent moment determining module 205, the several adjacent moments of group for determining the moment determine 6 of moment t Adjacent moment.

Absolute value determining module 206, for determining described group of several phases according to the three-phase voltage instantaneous signal sequence Adjacent moment corresponding absolute value.Figure 15 is a kind of electric network fault based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of absolute value determining module in identifying system, as shown in Figure 15, absolute value determining module 206 includes:

First group of periodic sequence selection unit 401, for selecting institute from the three-phase voltage instantaneous signal sequence It states three-phase voltage instantaneous signal sequence of the adjacent moment into previous cycle and is referred to as first group of periodic sequence；

Second group of periodic sequence selection unit 402, for selecting institute from the three-phase voltage instantaneous signal sequence The three-phase voltage instantaneous signal sequence stated in first group of periodic sequence previous cycle is referred to as second group of periodic sequence；

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

Failure start time determining module 207 is big for working as described group of several corresponding absolute values of adjacent moment When the absolute value threshold value, the moment is failure start time.

Then the tm1 moment has occurred and that failure, calculates separately the several corresponding absolute values of adjacent moment of group at this time, specifically , the absolute value that step S403 is determined 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 is determined according to the three-phase voltage instantaneous signal sequence in addition to failure start time, according to described Failure start time determines the fault type of the short circuit malfunction.Specifically, comparing what three-phase voltage signal failure started The successive time judges fault type.Influence due to failure with respect to non-faulting phase has a small delay, therefore can basis Each fault moment first judges fault type later.When the fault moment of a certain phase is obviously earlier than the fault moment of other two-phases, And the fault moment of other two-phase is close, it may be considered that single-phase short circuit has occurred；When the fault moment of a certain phase is obviously late In the fault moment of other two-phases, and the fault moment of other two-phase is close, it may be considered that line to line fault has occurred；When three When the fault moment of phase is similar, it may be considered that three-phase shortcircuit has occurred.It is introduced one by one with reference to the accompanying drawing.

Figure 16 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment one of type determination device, as shown in Figure 16, which specifically includes in embodiment 1:

Failure start time determining module 501, when for determining A phase fault since the failure start time Quarter, B phase fault start time and C phase fault start time.In a particular embodiment, it is determined in step S102 whole The failure start time T=min (ta1, tb1, tc1) of body therefrom extracts A phase fault start time ta1, B phase fault and starts Moment tb1 and C phase fault start time tc1.

First threshold obtains module 502, for obtaining preset first threshold, in a particular embodiment, the One threshold value can be worth based on practical experience to be preset, and such as first threshold is 1ms.

Difference determining module 503 two-by-two, for determining the A phase fault start time, B phase fault start time respectively And the difference of C phase fault start time two-by-two；

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

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

Figure 17 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment two of type determination device, the device specifically include in the second embodiment:

Second threshold obtains module 506, for obtaining preset second threshold, in a particular embodiment, the Two threshold values can be worth based on practical experience to be preset, and such as second threshold is 2ms.

First difference determining module 507, for determining the A phase fault start time and B phase fault start time Difference, referred to as the first difference；

Second difference determining module 508, for determining the A phase fault start time and C phase fault start time Difference, referred to as the second difference；

Third difference determining module 509, for determining the B phase fault start time and C phase fault start time Difference, referred to as third difference；

Second fault type determining module 510 is less than the first threshold, institute for the absolute value when first difference State that the second difference is negative and its absolute value is greater than the second threshold, the third difference is negative and its absolute value is greater than described the When two threshold values, the fault type of the short circuit malfunction is C phase short trouble.

Figure 18 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment three of type determination device, the device specifically include in the third embodiment:

Third fault type determining module 511 is less than the first threshold, institute for the absolute value when the third difference State that the first difference is positive and its absolute value is greater than the second threshold, second difference is positive and its absolute value is greater than described the When two threshold values, the fault type of the short circuit malfunction is A phase short trouble.

Figure 19 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment four of type determination device, the device specifically include in the fourth embodiment:

4th fault type determining module 512 is less than the first threshold, institute for the absolute value when second difference State that third difference is positive and its absolute value is greater than the second threshold, first difference is negative and its absolute value is greater than described the When two threshold values, the fault type of the short circuit malfunction is B phase short trouble.

That is, in a particular embodiment, as | ta1-tb1 | be greater than the second threshold and a1 be less than tb1, | ta1- Tc1 | be less than the first threshold, | ta1-tc1 | when being greater than the second threshold and tb1 and being greater than tc1, it is believed that tc1 and ta1 Approximately equal, tc1 is significantly less than tb1, and ta1 is significantly less than tb1, then the fault type of short circuit malfunction is B phase short trouble.

Figure 20 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment five of type determination device, the device specifically include in embodiment five:

5th fault type determining module 513 is less than the first threshold, institute for the absolute value when first difference State that the second difference is positive and its absolute value is greater than the second threshold, the third difference is positive and its absolute value is greater than described the When two threshold values, the fault type of the short circuit malfunction is AB phase short trouble.

Figure 21 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment six of type determination device, the device specifically include in embodiment six:

6th fault type determining module 514 is less than the first threshold, institute for the absolute value when the third difference State that the first difference is negative and its absolute value is greater than the second threshold, second difference is negative and its absolute value is greater than described the When two threshold values, the fault type of the short circuit malfunction is BC phase short trouble.

Figure 22 is failure in a kind of electric network fault identifying system based on three-phase voltage signal provided in an embodiment of the present invention The structural block diagram of the embodiment seven of type determination device, the device specifically include in embodiment seven:

7th fault type determining module 515 is less than the first threshold, institute for the absolute value when second difference State that third difference is negative and its absolute value is greater than the second threshold, first difference is positive and its absolute value is greater than described the When two threshold values, the fault type of the short circuit malfunction is CA phase short trouble.

That is, in a particular embodiment, as | ta1-tb1 | be greater than the second threshold and a1 be greater than tb1, | ta1- Tc1 | be less than the first threshold, | tb1*tc1 | when being greater than the second threshold and tb1 and being less than tc1, it is believed that tc1 and ta1 Approximately equal, tc1 is significantly greater than tb1, and ta1 is significantly greater than tb1, then the fault type of short circuit malfunction is the short circuit event of CA phase Barrier.

More than, it is a kind of electric network fault identifying system based on three-phase voltage signal provided by the invention, passes through acquisition The three-phase voltage instantaneous signal sequence of blower output end bus during short circuit malfunction, determination are out of order start time, in turn The fault type of short circuit malfunction can be determined according to failure start time, the present invention realizes the event of accurate judgement grid short circuit Hinder type, and can accurately determine that the moment occurs for failure.

Below with reference to specific embodiment, to a kind of electric network fault identification based on three-phase voltage signal provided by the invention Method and system elaborate.In this specific embodiment, the sampling period be Δ t=0.1ms three-phase voltage signal such as Under:

The preset period is set as T=20ms, then a cycle single-phase voltage data volume is 200.It is with A phase voltage Example:

T=t when initial₄₀₀；

Data when initial in data1 are as follows: u_A(t₂₀₁)、u_A(t₂₀₂)、u_A(t₂₀₃)、…、u_A(t₄₀₀)。

Data when initial in data2 are as follows: 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 whether data3 is small and is greater than threshold epsilon.

(1) if data3 is no more than threshold value

T=t₄₀₀+ Δ t=t₄₀₁；

Because of t₄₀₁<t_n；

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

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

Calculating data3 at this time is then following formula:

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

Jump to and judge whether data3 small and be greater than threshold epsilon, in the embodiment threshold value of data3 can for 0.4~0.5 multiplied by 10 biquadratic.

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

At this point,

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

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

Terminate if being greater than tn at the time of last number in data1 in whole process.

Ta1, tb1, tc1 can be found out using same method, then whole failure start time T1=min (ta1, tb1,tc1)。

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

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

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

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

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

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

If tc1 is approximately equal with ta1, tc1 and ta1 are 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 are referred to as two-phase short-circuit fault.

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

In conclusion the electric network fault recognition methods that the embodiment of the invention provides a kind of based on three-phase voltage signal and System, by the three-phase voltage instantaneous signal sequence of blower output end bus during acquisition short circuit malfunction, determination is out of order Start time, and then the fault type of short circuit malfunction can be determined according to failure start time, the present invention realizes accurately Judge short circuit malfunction type, and can accurately determine that the moment occurs for failure.

Those of ordinary skill in the art will appreciate that realizing all or part of the process in above-described embodiment method, Ke Yitong Computer program is crossed to instruct relevant hardware and complete, the program can be stored in general computer-readable storage medium In, the program is when being executed, it may include such as the process of the embodiment of above-mentioned each method.Wherein, the storage medium can be magnetic Dish, CD, read-only memory (Read-Only Memory, ROM) or random access memory (Random Access Memory, RAM) etc..

Those skilled in the art will also be appreciated that the various functions that the embodiment of the present invention is listed are by hardware or soft Part depends on the design requirement of specific application and whole system to realize.Those skilled in the art can be specific for every kind Using various methods can be used and realize the function, but this realization is understood not to protect beyond the embodiment of the present invention The range of shield.

Specific embodiment is applied in the present invention, and principle and implementation of the present invention are described, above embodiments Explanation be merely used to help understand method and its core concept of the invention；At the same time, for those skilled in the art, According to the thought of the present invention, there will be changes in the specific implementation manner and application range, in conclusion in this specification Appearance should not be construed as limiting the invention.

Claims

1. a kind of electric network fault recognition methods based on three-phase voltage signal, which is characterized in that the method includes:

The three-phase voltage instantaneous signal sequence of blower output end bus during acquisition short circuit malfunction；

Failure start time is determined according to the three-phase voltage instantaneous signal sequence；

The fault type of the short circuit malfunction is determined according to the failure start time；

Wherein, determine that failure start time includes: to obtain preset week according to the three-phase voltage instantaneous signal sequence Phase and moment；The moment corresponding integrated value is determined according to the three-phase voltage instantaneous signal sequence；Acquisition is set in advance Fixed integral threshold and absolute value threshold value；When the moment corresponding integrated value is greater than the integral threshold, obtain preparatory The group number of setting；Determine the several adjacent moments of the group at the moment；Institute is determined according to the three-phase voltage instantaneous signal sequence State the several corresponding absolute values of adjacent moment of group；When described group of several corresponding absolute values of adjacent moment are all larger than institute When stating absolute value threshold value, the moment is failure start time.

2. the method according to claim 1, wherein referring to during the short circuit malfunction in fan outlet Place occurs short circuit malfunction or carries out the failure generation of low voltage crossing experiment simulating grid short trouble at fan outlet Before, during failure and after failure removal until before voltage and current restores failure.

3. according to the method described in claim 2, it is characterized in that, determining institute according to the three-phase voltage instantaneous signal sequence Stating moment corresponding integrated value includes:

Three-phase voltage of the moment into previous cycle is selected from the three-phase voltage instantaneous signal sequence instantaneously to believe Number sequence is referred to as period 1 sequence；

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

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

The absolute value is integrated within the period, obtains the moment corresponding integrated value.

4. according to the method described in claim 2, it is characterized in that, determining institute according to the three-phase voltage instantaneous signal sequence Stating the several corresponding absolute values of adjacent moment of group includes:

Three-phase voltage wink of the adjacent moment into previous cycle is selected from the three-phase voltage instantaneous signal sequence When signal sequence be referred to as first group of periodic sequence；

From the three-phase electricity selected in the three-phase voltage instantaneous signal sequence in first group of periodic sequence previous cycle Pressure instantaneous signal sequence is referred to as second group of periodic sequence；

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

5. the method according to claim 3 or 4, which is characterized in that determine the power grid according to the failure start time The fault type of short trouble includes:

Determine that A phase fault start time, B phase fault start time and C phase fault are opened from the failure start time Begin the moment；

Obtain preset first threshold；

The A phase fault start time, the difference of B phase fault start time and C phase fault start time two-by-two are determined respectively Value；

Determine the absolute value of the difference；

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

6. the method according to claim 3 or 4, which is characterized in that determine the power grid according to the failure start time The fault type of short trouble includes:

Obtain preset first threshold and second threshold；

Determine the difference of the A phase fault start time and B phase fault start time, referred to as the first difference；

Determine the difference of the A phase fault start time and C phase fault start time, referred to as the second difference；

Determine the difference of the B phase fault start time and C phase fault start time, referred to as third difference；

When the absolute value of first difference is less than the first threshold, second difference is negative and its absolute value is greater than described Second threshold, when the third difference is negative and its absolute value is greater than the second threshold, the failure of the short circuit malfunction Type is C phase short trouble.

7. according to the method described in claim 6, it is characterized in that, determining the grid short circuit according to the failure start time The fault type of failure further include:

When the absolute value of the third difference is less than the first threshold, first difference is positive and its absolute value is greater than described Second threshold, when second difference is positive and its absolute value is greater than the second threshold, the failure of the short circuit malfunction Type is A phase short trouble.

8. according to the method described in claim 6, it is characterized in that, determining the grid short circuit according to the failure start time The fault type of failure further include:

When the absolute value of second difference is less than the first threshold, the third difference is positive and its absolute value is greater than described Second threshold, when first difference is negative and its absolute value is greater than the second threshold, the failure of the short circuit malfunction Type is B phase short trouble.

9. according to the method described in claim 6, it is characterized in that, determining the grid short circuit according to the failure start time The fault type of failure further include:

When the absolute value of first difference is less than the first threshold, second difference is positive and its absolute value is greater than described Second threshold, when the third difference is positive and its absolute value is greater than the second threshold, the failure of the short circuit malfunction Type is AB phase short trouble.

10. according to the method described in claim 6, it is characterized in that, determining that the power grid is short according to the failure start time The fault type of road failure further include:

When the absolute value of the third difference is less than the first threshold, first difference is negative and its absolute value is greater than described Second threshold, when second difference is negative and its absolute value is greater than the second threshold, the failure of the short circuit malfunction Type is BC phase short trouble.

11. according to the method described in claim 6, it is characterized in that, determining that the power grid is short according to the failure start time The fault type of road failure further include:

When the absolute value of second difference is less than the first threshold, the third difference is negative and its absolute value is greater than described Second threshold, when first difference is positive and its absolute value is greater than the second threshold, the failure of the short circuit malfunction Type is CA phase short trouble.

12. a kind of electric network fault identifying system based on three-phase voltage signal, which is characterized in that the system includes:

Instantaneous signal acquisition device, the three-phase voltage instantaneous signal for blower output end bus during acquiring short circuit malfunction Sequence；

Failure start time determining device, for determining failure start time according to the three-phase voltage instantaneous signal sequence；

Fault type determining device, for determining the fault type of the short circuit malfunction according to the failure start time；

Wherein, the failure start time determining device include the period obtain module, for obtain the preset period with And the moment；Integrated value determining module, for determining the moment corresponding product according to the three-phase voltage instantaneous signal sequence Score value；Integral threshold module, for obtaining preset integral threshold and absolute value threshold value；Group number obtains module, is used for When the moment corresponding integrated value is greater than the integral threshold, preset group of number is obtained；Adjacent moment determining module, The several adjacent moments of group for determining the moment；Absolute value determining module, for instantaneously being believed according to the three-phase voltage Number sequence determines described group of several corresponding absolute value of adjacent moment；Failure start time determining module, for when described When the several corresponding absolute values of adjacent moment of group are all larger than the absolute value threshold value, when the moment is that failure starts It carves.

13. system according to claim 12, which is characterized in that refer to go out in blower during the short circuit malfunction Short circuit malfunction occurs at mouthful or carries out the failure hair of low voltage crossing experiment simulating grid short trouble at fan outlet Before death, until before voltage and current recovery failure during failure and after failure removal.

14. system according to claim 13, which is characterized in that the integrated value determining module includes:

Period 1 sequence selection unit, for selecting the moment forward from the three-phase voltage instantaneous signal sequence Three-phase voltage instantaneous signal sequence in one period is referred to as period 1 sequence；

Second round sequence selection unit, for selecting the period 1 from the three-phase voltage instantaneous signal sequence Three-phase voltage instantaneous signal sequence in sequence previous cycle is referred to as second round sequence；

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

Integrated value determination unit obtains the moment corresponding product for integrating within the period to the absolute value Score value.

15. system according to claim 13, which is characterized in that the absolute value determining module includes:

First group of periodic sequence selection unit, when for selecting described adjacent from the three-phase voltage instantaneous signal sequence The three-phase voltage instantaneous signal sequence carved into previous cycle is referred to as first group of periodic sequence；

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

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

16. system according to claim 14 or 15, which is characterized in that the fault type determining device includes:

Failure start time determining module, for determining A phase fault start time, B phase from the failure start time Failure start time and C phase fault start time；

First threshold obtains module, for obtaining preset first threshold；

Difference determining module two-by-two, for determining A phase fault start time, B phase fault start time and the C phase respectively The difference of failure start time two-by-two；

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

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

17. system according to claim 16, which is characterized in that the fault type determining device further include:

Second threshold obtains module, for obtaining preset second threshold；

First difference determining module claims for determining the difference of the A phase fault start time and B phase fault start time For the first difference；

Second difference determining module claims for determining the difference of the A phase fault start time and C phase fault start time For the second difference；

Third difference determining module claims for determining the difference of the B phase fault start time and C phase fault start time For third difference；

Second fault type determining module is less than the first threshold, described second for the absolute value when first difference Difference is negative and its absolute value is greater than the second threshold, and the third difference is negative and its absolute value is greater than the second threshold When, the fault type of the short circuit malfunction is C phase short trouble.

18. system according to claim 17, which is characterized in that the fault type determining device further include:

Third fault type determining module is less than the first threshold, described first for the absolute value when the third difference Difference is positive and its absolute value is greater than the second threshold, and second difference is positive and its absolute value is greater than the second threshold When, the fault type of the short circuit malfunction is A phase short trouble.

19. system according to claim 17, which is characterized in that the fault type determining device further include:

4th fault type determining module is less than the first threshold, the third for the absolute value when second difference Difference is positive and its absolute value is greater than the second threshold, and first difference is negative and its absolute value is greater than the second threshold When, the fault type of the short circuit malfunction is B phase short trouble.

20. system according to claim 17, which is characterized in that the fault type determining device further include:

5th fault type determining module is less than the first threshold, described second for the absolute value when first difference Difference is positive and its absolute value is greater than the second threshold, and the third difference is positive and its absolute value is greater than the second threshold When, the fault type of the short circuit malfunction is AB phase short trouble.

21. system according to claim 17, which is characterized in that the fault type determining device further include:

6th fault type determining module is less than the first threshold, described first for the absolute value when the third difference Difference is negative and its absolute value is greater than the second threshold, and second difference is negative and its absolute value is greater than the second threshold When, the fault type of the short circuit malfunction is BC phase short trouble.

22. system according to claim 17, which is characterized in that the fault type determining device further include:

7th fault type determining module is less than the first threshold, the third for the absolute value when second difference Difference is negative and its absolute value is greater than the second threshold, and first difference is positive and its absolute value is greater than the second threshold When, the fault type of the short circuit malfunction is CA phase short trouble.