CN102589890A - Integrated fault diagnostic method of steam turbine based on CPN (counter-propagation network) and D-S (dempster-shafer) evidences - Google Patents

Integrated fault diagnostic method of steam turbine based on CPN (counter-propagation network) and D-S (dempster-shafer) evidences Download PDF

Info

Publication number
CN102589890A
CN102589890A CN2012100507549A CN201210050754A CN102589890A CN 102589890 A CN102589890 A CN 102589890A CN 2012100507549 A CN2012100507549 A CN 2012100507549A CN 201210050754 A CN201210050754 A CN 201210050754A CN 102589890 A CN102589890 A CN 102589890A
Authority
CN
China
Prior art keywords
cpn
steam turbine
independent
neutral nets
fault
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN2012100507549A
Other languages
Chinese (zh)
Inventor
彭道刚
张�浩
夏飞
李辉
钱玉良
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai University of Electric Power
University of Shanghai for Science and Technology
Original Assignee
Shanghai University of Electric Power
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai University of Electric Power filed Critical Shanghai University of Electric Power
Priority to CN2012100507549A priority Critical patent/CN102589890A/en
Publication of CN102589890A publication Critical patent/CN102589890A/en
Pending legal-status Critical Current

Links

Images

Abstract

The invention relates to an integrated fault diagnostic method of a steam turbine based on a CPN (counter propagation network) and D-S (Dempster-Shafer) evidences. The integrated fault diagnostic method utilizes the advantages of a CPN and a D-S evidence theory and takes steam turbine vibration state parameters collected by different sensors as independent data samples aiming at the steam turbine of a power plant; and after being subjected to the characteristic extraction and processing, and the parameter normalization processing, the independent data samples are input into respectively independent CPN to be trained, so that each independent CPN can form a non-linear mapping of a fault symptom to a fault mode. And then, a D-S evidence theory method is used for carrying out further data fusion diagnosis on a diagnosed result of each CPN, so as to improve the accuracy and the reliability of the diagnosed result. Therefore, more accurate diagnosis and analysis on the current operation state of the steam turbine is implemented.

Description

The integrated method for diagnosing faults of steam turbine based on CPN networks and D-S evidences
Technical field
The present invention relates to a kind of Steam Turbine Fault Diagnosis, the integrated method for diagnosing faults of more particularly to a kind of steam turbine based on CPN networks and D-S evidences.
Background technology
Turbo-generator Set is the capital equipment of power-generating enterprise, and steam turbine constantly produces a large amount of different information in the process of running, and these information reflect the running status of steam turbine in terms of different.Because steam turbine structure is more complicated, running environment is more special, unit failure situation is inevitable, and failure mode is various, there are many fault characteristic signals, including temperature, pressure, amplitude, voltage, electric current, flow, power etc., and the fault signature wherein included with vibration signal is most, it more can rapidly, directly reflect the running status of unit, also be easier monitored and analyze.Therefore, the research of Steam Turbine Fault Diagnosis is carried out, for finding failure cause and position, the operational reliability of unit is improved, ensures that unit safety, economical operation are significant.
Information fusion technology be by from different purposes, different time, different spaces information, automatically analyzed by computer technology under certain criterion and comprehensive, unified feature representation information is formed, so that system obtains the technology than single piece of information source more accurate, more complete estimation and judgement.It provides first and then reliable method for the information processing and decision problem for solving the information age.In multisensor syste, the general principle of information fusion is just as the process of human brain integrated treatment information, by various sensors provide in the time or spatially redundancy or complementary information, according to certain criterion optimum organization, produce the reasonable description to observing environment.Information fusion technology is on the basis of integrated treatment is carried out to the information of multisensor, to realize real-time state monitoring, the mutation forecasting even fault diagnosis of signal and the alarm to equipment applied to equipment fault diagnosis.In fault diagnosis field, information fusion process can be divided into data Layer, characteristic layer, three levels of decision-making level, and these three levels are represented to the abstract of the different depths of initial data respectively.Compared with traditional fault diagnosis technology, information fusion technology has higher diagnosis accuracy and confidence level.
Evidence theory in information fusion technology is a kind of reasoning method under uncertainty, is proposed first by Dempster, and is further grown up by Shafer, forms a set of mathematical theory on evidence, thus also known as D-S evidence theory.D-S evidence theory is mainly according to reliability function computing, and it is a kind of data fusion method for solving uncertain problem.D-S evidence theory does not need prior information, and describes uncertain information using the method for interval estimation, solves on probabilistic method for expressing.Therefore, D-S evidence theory has the ability of very strong processing uncertain information, do not know that with uncertain aspect and accurately in terms of reflection evidence-gathering there is very big flexibility distinguishing, expression and synthesis for uncertain information provide strong method, decision level information fusion is particularly adapted to, is widely applied in fields such as pattern-recognition, fault diagnosis, problem prediction, expert systems.
Counterpropagation network(Counter-propagation Network, abbreviation CPN)It is a kind of novel feature mapping network of rising in recent years, it can overcome BP neural network conventional to be at present absorbed in local minimum point, slow and poor astringency the defect of pace of learning.CPN neutral nets get up Kohonen Feature Mappings network and the basic competitive type network integrations of Grossberg, have played respective speciality, it is adaptable to fault diagnosis, pattern classification, function approximation, statistical analysis and data compression etc..
The content of the invention
The present invention be directed to the important sex chromosome mosaicism of fault diagnosis of the steam turbine comprising vibration signal, propose a kind of integrated method for diagnosing faults of the steam turbine based on CPN networks and D-S evidences, using turbine rotor vibration analogue experiment installation as test platform, it regard the Steam Turbine Vibration state parameter collected from different sensors as independent data sample, using CPN neutral nets and the advantage of D-S evidence theory, realize and steam turbine current operating conditions are carried out more accurately to diagnose and analyze.
The technical scheme is that:A kind of integrated method for diagnosing faults of steam turbine based on CPN networks and D-S evidences, method is comprised the following specific steps that:
1)It regard the Steam Turbine Vibration state parameter collected from sensor on turbine rotor vibration simulator stand as independent data sample, each independent CPN neutral nets are input to after the processing of feature extraction, processing and parameter normalization to be trained so that each independent CPN neutral nets can form failure symptom to the Nonlinear Mapping of fault mode;
2)Carried out using each independent CPN neutral nets after fault diagnosis, the output valve of CPN neutral nets be normalized using formula below, be converted into should CPN neutral nets various malfunctions basic probability assignment BPA,
Figure 2012100507549100002DEST_PATH_IMAGE001
Figure 82576DEST_PATH_IMAGE002
Figure 2012100507549100002DEST_PATH_IMAGE003
  
Wherein
Figure 403835DEST_PATH_IMAGE004
Represent the
Figure 158165DEST_PATH_IMAGE006
Individual evidence in CPN networks
Figure 2012100507549100002DEST_PATH_IMAGE007
Individual output result;
Figure 708226DEST_PATH_IMAGE008
Represent
Figure 293928DEST_PATH_IMAGE006
Individual evidence is to stateBPA;
3)Further data fusion is carried out to the diagnostic results of each failure CPN neutral nets according to the fusion rule of D-S evidence theory, try to achieve its it is orthogonal and
Figure 2012100507549100002DEST_PATH_IMAGE009
, the basic probability assignment of each status fault state, obtains fault diagnosis result after as merging.
The beneficial effects of the present invention are:Steam turbine integrated method for diagnosing faults of the invention based on CPN networks and D-S evidences, utilize CPN neutral nets and the advantage of D-S evidence theory, for power plant steam turbine, it regard the Steam Turbine Vibration state parameter collected from different sensors as independent data sample, each independent CPN neutral nets are inputted after the processing of feature extraction, processing and parameter normalization to be trained so that each independent CPN neutral nets can form failure symptom to the Nonlinear Mapping of fault mode.Occur simultaneously because each independent fault signature and fault mode are present, further data fusion diagnosis is carried out to the diagnostic result of each CPN neutral net using D-S evidence theory method, steam turbine current operating conditions are carried out more accurately to diagnose and analyze so as to realize.
Brief description of the drawings
Fig. 1 is vibration faults of turbine rotor simulator stand structural representation of the present invention;
Fig. 2 is the steam turbine integrated fault diagnosis model figure of the invention based on CPN networks and D-S evidence theory;
Fig. 3 is the topology diagram of CPN neutral nets of the present invention.
Embodiment
In actual motion, the common failure of steam turbine has following several:Rotor unbalance, rotor misalignment, oil whirl and oil whip, fulcrum bearing loosen, rotor impact and rub and axle crack fault etc..Wherein, rotor unbalance is the most common failure of steam turbine, the reason for causing steam turbine synchronous vibration may have original quality imbalance, rotor thermal unbalance, rotor thermal bending, rotary part to come off and rotor part fouling etc., and these reasons will all cause the imbalance fault of rotor.Under certain working condition, rotor-bearing system also occurs that the problem of oil whirl and oil whip, and high vibration of the rotor journal in oil film will directly result in the damage of element part.
Steam turbine integrated method for diagnosing faults of the invention based on CPN neutral nets and D-S evidence theory is using turbine rotor vibration analogue experiment installation as test platform, by changing rotor speed, axis rigidity, mass unbalance, the friction of bearing and impact condition and the form of shaft coupling, the test platform can effectively reproduce the common vibration fault produced by steam turbine.Test platform includes six eddy current displacement sensors, a photoelectric sensor and two magnetoelectric velocity transducers, the real time data of testing stand during for gathering fault simulation experiment.The present invention is simulated on test platform to the most common failure of steam turbine, while being sampled to whole boosting velocity procedure, to provide multisensor in fault data not in the same time.Need the diverse location in rotating shaft that multiple sensors are installed in order to obtain required fault-signal, when every kind of malfunction test, while the signal for choosing sensor carries out convergence analysis.
The present invention illustrates embodiment by taking oil whirl and oil whip failure as an example.
When steam turbine axle journal is rotated in bearing shell, the gap between bearing shell and axle journal can form oil film, and the hydrodynamic pressure of oil film makes axle journal have bearing capacity.Once the bearing capacity of oil film reaches balance with external applied load, axle journal is just in equilbrium position, and when rotating shaft is by certain external disturbance, bearing film will not only produce along the elastic restoring force of offset direction to keep the balance with external load, and produce one perpendicular to the tangential unstability component of offset direction to drive rotor formation and rotor direction of rotation identical whirling motion.Because the eddy velocity of axle journal is close to the half of rotating speed, often it is referred to as " half-speed vortex ".After generation whirling motion, no matter amplitude size, rotor all loses stability, i.e., so-called rotor unstability.Under certain condition, though rotor unstability, axle journal may the only whirling motion in the range of a very little, i.e. whirling motion amplitude very little, may be still stable from the perspective of machine run.Whirling motion angular speed increases with the raising of working speed, but always it is about equal to the half of velocity of rotation, when rotating shaft rotating speed is increased to slightly above after 2 times of first critical speed, first critical speed of the whirling motion angular speed of half-speed vortex just with rotating shaft coincides, so as to produce resonance, strong covibration is shown as.Orbit of shaft center suddenly becomes the irregular curve of diffusion simultaneously, if continuing to improve rotating speed, the frequency of vortex motion of rotor keeps constant, consistently equal to the first critical speed of rotor, and this phenomenon is oil whip.
Due to being limited by limit speed, when doing oil whip experiment, this testing stand needs that rotor-support-foundation system first critical speed is down into below 4000rpm by way of increasing wheel disc, to be observed that oil whip phenomenon near 9000rpm.Vibration faults of turbine rotor simulator stand is as shown in figure 1, motor 1, bearing I 4, bearing II 7, the bearing IV 16 of bearing III 9 are fixed on pedestal 17.There is shaft coupling 2 to connect between motor 1 and bearing I 4, there is shaft coupling 8 to connect between bearing II 7 and bearing III 9, the testing stand uses twin spans rotor, from one wheel disc of installing at whirling motion bearing block 2/3 in oil whirl rotating shaft, it is 5 wheel disc A, 6 wheel disc B, 11 wheel disc C respectively equipped with three wheel discs on rotor.Along axial arranged a photoelectric sensor 3 and two current vortex sensors 10,12 of rotating shaft, wherein photoelectric sensor 3 is located at the right-hand member of shaft coupling 2 between motor 1 and bearing I 4, rotating speed and phase for measuring rotor;Current vortex sensor 10 is is arranged vertically and current vortex sensor 12 is arranged horizontally, the amplitude for rotor.X, Y-direction eddy current sensor are installed on eddy current sensor support, and distance of the adjustment probe to rotor surface on request;The output signal line of preamplifier is connected on vialog, and vialog is connected on host computer.During experiment, open needle valve lubricating cup 15, until oil drips from bearing, firing test motor, gradually steps up rotating speed, about in 3000~4000rpm, generation whirling motion, if whirling motion does not occur immediately, axle is lightly lifted in whirling motion bearing end using nylon preload rod, continues to raise rotating speed until oil whip failure occurs for testing stand.Excessive to prevent from refueling, testing stand has an oil return opening 14 on the side of bearing IV, and unnecessary oil is flowed into oil-containing groove 13.
The present invention is test platform for vibration faults of turbine rotor analogue experiment installation, it regard the Steam Turbine Vibration state parameter collected from different sensors as independent data sample, each independent CPN neutral nets are inputted after the processing of feature extraction, processing and parameter normalization to be trained so that each independent CPN neutral nets can form failure symptom to the Nonlinear Mapping of fault mode.Because these vibration fault states are taken from same simulator stand, so each there is common factor in independent fault signature and fault mode, further data fusion is carried out to the diagnostic result of each CPN neutral net using D-S evidence theory method, steam turbine current operating conditions are carried out more accurately to diagnose and analyze so as to realize.Fig. 2 show the integrated fault diagnosis model of steam turbine based on CPN neutral nets and D-S evidence theory.
The implementation process of specific fault diagnosis algorithm of the invention is described below:
, it is necessary to be trained to CPN neutral nets before application CPN neutral nets carry out Steam Turbine Fault Diagnosis.The topological structure of CPN neutral nets by CPN neutral nets symbol as shown in figure 3, set as follows:If the input vector of CPN networks is
Figure 507009DEST_PATH_IMAGE010
, the output vector of competition layer is, the reality output vector of output layer is
Figure 47711DEST_PATH_IMAGE012
, target output vector is
Figure 2012100507549100002DEST_PATH_IMAGE013
, whereinThe respectively neuron number of CPN neural network input layers, competition layer and output layer,
Figure 2012100507549100002DEST_PATH_IMAGE015
, wherein
Figure 901715DEST_PATH_IMAGE016
Represent the number of CPN neural network failure samples.It is by the connection weight vector of input layer to competition layer
Figure 2012100507549100002DEST_PATH_IMAGE017
;It is by the connection weight vector of competition layer to output layer
Figure 692953DEST_PATH_IMAGE018
The learning process of CPN neutral nets is as follows:
(1)Data prediction:By all input patterns
Figure DEST_PATH_IMAGE019
According to formula(1)It is normalized, and weight vector will be connected
Figure 584817DEST_PATH_IMAGE020
With
Figure 2012100507549100002DEST_PATH_IMAGE021
Assign the random value in [0,1].
Figure 82795DEST_PATH_IMAGE022
,
Figure DEST_PATH_IMAGE023
,
Figure 651179DEST_PATH_IMAGE024
; 
(1)
(2)CPN neural metwork trainings:
1)Input layer to competition layer learns without teacher's type:
By connection weight vector
Figure 680446DEST_PATH_IMAGE020
According to formula(2)It is normalized
,
Figure 562952DEST_PATH_IMAGE026
,
Figure DEST_PATH_IMAGE027
; 
(2)
By
Figure 977752DEST_PATH_IMAGE028
Individual input patternNetwork input layer is supplied to, then according to formula(3)Calculate each neuron in competition layer weighting input and:
Figure DEST_PATH_IMAGE029
,
Figure 171284DEST_PATH_IMAGE030
  
(3)
According to formula(4)Try to achieve connection weight vectorIn with
Figure 126788DEST_PATH_IMAGE019
Closest vector
,
(4)
And by its corresponding neuron
Figure 787708DEST_PATH_IMAGE032
Output
Figure DEST_PATH_IMAGE033
It is set as 1, the output of remaining competition layer neuron
Figure 775255DEST_PATH_IMAGE034
It is set as 0;Weight vector will finally be connected
Figure DEST_PATH_IMAGE035
According to formula(5)It is modified, and by connection weight
Figure 999563DEST_PATH_IMAGE035
Again normalize.
Figure 139689DEST_PATH_IMAGE036
,
Figure DEST_PATH_IMAGE037
  
(5)
Wherein
Figure 486356DEST_PATH_IMAGE038
For learning rate,
Figure DEST_PATH_IMAGE039
2)Competition layer has the study of teacher's type to output layer:
According to formula(6)To correct competition layer to the connection weight vector of output layer
Figure 711932DEST_PATH_IMAGE040
Figure DEST_PATH_IMAGE041
,
Figure 474352DEST_PATH_IMAGE042
  
(6)
Wherein
Figure DEST_PATH_IMAGE043
For learning rate,
Figure 718252DEST_PATH_IMAGE044
Due to having determined competition layer neuron in the study of input layer to competition layer
Figure 4131DEST_PATH_IMAGE032
1 is output as, and other neurons are output as 0, so only needing to correct neuron
Figure 903954DEST_PATH_IMAGE032
Corresponding connection weight vector, institute's above formula can be with abbreviation into formula(7),
Figure DEST_PATH_IMAGE045
,
(7)
The weighting input of each neuron of output layer is tried to achieve, and is translated into the real output value such as formula of output layer neuron(8)It is shown.It can similarly simplify such as formula(9)In form
Figure DEST_PATH_IMAGE047
 
(8)
Figure 568471DEST_PATH_IMAGE048
  
(9)
3)The repetition training of CPN networks:
Will
Figure 7673DEST_PATH_IMAGE016
Individual input pattern is all supplied to CPN neutral nets learn without teacher's type and has the study of teacher's type, completes the training of a CPN neutral net.Make again
Figure DEST_PATH_IMAGE049
, by input pattern
Figure 457109DEST_PATH_IMAGE019
E-learning is re-supplied to, untilOr untill network error E is less than predetermined error.Wherein
Figure DEST_PATH_IMAGE051
For study total degree set in advance.
Figure 530556DEST_PATH_IMAGE052
 
(10)
In the present invention, CPN neural network training process algorithms are improved.Due in standard CPN neutral nets, if the triumph neuron repeatedly trained is identical, then algorithm is only adjusted to the corresponding connection weight of the neuron, so that the information record of multiple input patterns is in same neuron, this can cause the chaotic situation of the information of record, be unfavorable for improving the training effect of CPN neutral nets.In order to avoid such case, it is necessary to artificially intervene neuron, make the information record of fault mode in different neurons, so as to improve CPN neural metwork training effects.
According to formula(3)Calculate
Figure DEST_PATH_IMAGE053
Figure 389927DEST_PATH_IMAGE054
, in theseAccording to formula(4)The maximum weighting input of selection and
Figure DEST_PATH_IMAGE055
, as connect weight vectorIn with
Figure 995986DEST_PATH_IMAGE019
Closest vector.If
Figure 26259DEST_PATH_IMAGE056
's
Figure DEST_PATH_IMAGE057
(T is activated number of times for the competition layer neuron), then will
Figure 122391DEST_PATH_IMAGE056
Corresponding neuron causes as competition layer triumph neuron
Figure 381465DEST_PATH_IMAGE056
's
Figure 512232DEST_PATH_IMAGE049
;If, then select to remove
Figure 296835DEST_PATH_IMAGE056
Outer maximum weighting input and
Figure DEST_PATH_IMAGE059
If,
Figure 359600DEST_PATH_IMAGE059
's
Figure 344873DEST_PATH_IMAGE057
, then willCorresponding neuron causes as competition layer triumph neuron
Figure 787673DEST_PATH_IMAGE059
's, otherwise successively by weighting input and
Figure 493909DEST_PATH_IMAGE053
Order from big to small finds competition layer triumph neuron.Adjusted by such algorithm, can be by the information record of fault mode in different neurons.
After application CPN neutral nets carry out fault diagnosis, diagnostic result is normalized, fusion diagnosis is further carried out by D-S evidence theory, to improve the accuracy and reliability of diagnostic result.
D-S evidence theory is mainly according to reliability function computing, and it is a kind of data fusion method for solving uncertain problem.D-S evidence theory does not need prior information, and describes uncertain information using the method for interval estimation, solves on probabilistic method for expressing.
The following is the relating basic concepts of D-S evidence theory:
1)The basic conception of identification framework:
If
Figure 974569DEST_PATH_IMAGE060
For finite aggregate,
Figure DEST_PATH_IMAGE061
For natural number,
Figure 329327DEST_PATH_IMAGE060
In haveIndividual various separate possibility answers on certain proposition or it is assumed that then
Figure 693760DEST_PATH_IMAGE060
It is shared
Figure 407638DEST_PATH_IMAGE062
Individual subset, wherein all use of all subsets
Figure DEST_PATH_IMAGE063
To represent.The then finite aggregate
Figure 452955DEST_PATH_IMAGE060
For identification framework FD(Frame of Discement).
2)The basic conception of probability distribution function:
If
Figure 655354DEST_PATH_IMAGE060
For identification framework, proposition in field all by
Figure 204147DEST_PATH_IMAGE060
Subset represent, then set function
Figure 354505DEST_PATH_IMAGE064
Meet
Figure DEST_PATH_IMAGE065
   
(11)
Then claim
Figure 434588DEST_PATH_IMAGE009
It is
Figure 367909DEST_PATH_IMAGE063
On basic probability assignment BPA(Basic Probability Assignment);,
Figure DEST_PATH_IMAGE067
For
Figure 358048DEST_PATH_IMAGE068
Elementary probability number BPN(Basic Probability Number).
Figure 659847DEST_PATH_IMAGE068
Basic reliability distribution reflect pair
Figure 662438DEST_PATH_IMAGE068
The credibility size of itself.Represent for empty set
Figure 248140DEST_PATH_IMAGE070
Confidence level is not produced, and
Figure DEST_PATH_IMAGE071
Although represent can to any one proposition assign arbitrary size confidence level, require with all propositions assign confidence level and etc. 1.
3)The basic conception of belief function:
If
Figure 225455DEST_PATH_IMAGE060
For identification framework,
Figure 467080DEST_PATH_IMAGE064
For framework
Figure 70100DEST_PATH_IMAGE060
On basic probability assignment, then belief function(Belief Function)
Figure 447992DEST_PATH_IMAGE072
For
Figure DEST_PATH_IMAGE073
, whereinRepresent
Figure 731839DEST_PATH_IMAGE060
All subsets,
Figure DEST_PATH_IMAGE075
Also known as lower limit function, is represented pair
Figure 229817DEST_PATH_IMAGE068
Proposition is genuine trusting degree.
4)The basic conception of likelihood function:
If
Figure 548934DEST_PATH_IMAGE076
For
Figure 765152DEST_PATH_IMAGE060
On belief function, then likelihood function
Figure DEST_PATH_IMAGE077
For
Figure 709974DEST_PATH_IMAGE078
Figure DEST_PATH_IMAGE079
, wherein,
Figure DEST_PATH_IMAGE081
Also known as upper limit function or function can not be refuted.Due to
Figure 552476DEST_PATH_IMAGE075
Expression pair
Figure 52728DEST_PATH_IMAGE068
For genuine trusting degree, so
Figure 738924DEST_PATH_IMAGE082
Mean that pair
Figure DEST_PATH_IMAGE083
It is true(I.e.
Figure 758964DEST_PATH_IMAGE068
It is false)Trusting degree, therefore likelihood function
Figure 872413DEST_PATH_IMAGE081
Expression pair
Figure 859961DEST_PATH_IMAGE068
For non-false trusting degree.
5)The basic conception of burnt member:
If
Figure 84269DEST_PATH_IMAGE084
, then claimFor belief function
Figure DEST_PATH_IMAGE085
Jiao's member, the unions of all burnt members are referred to as
Figure 502885DEST_PATH_IMAGE085
Core.
After the basic conception of above D-S evidence theory is established, the rule of evidence combined effect can be reflected by the fusion rule of D-S evidence theory.For same thing, according to different sources of evidence, it can set
Figure 712150DEST_PATH_IMAGE086
With
Figure DEST_PATH_IMAGE087
It is same identification framework
Figure 740149DEST_PATH_IMAGE060
On two belief functions, simultaneously
Figure 734781DEST_PATH_IMAGE088
With
Figure DEST_PATH_IMAGE089
It is its corresponding BPA function, if they are separate, corresponding belief function
Figure 252350DEST_PATH_IMAGE086
WithIt is also separate.According to
Figure 531332DEST_PATH_IMAGE088
With
Figure 567422DEST_PATH_IMAGE089
A new BPA function can be calculated
Figure 193575DEST_PATH_IMAGE090
, corresponding belief function
Figure DEST_PATH_IMAGE091
It can be passed through according to the definition of belief function
Figure 377432DEST_PATH_IMAGE090
To try to achieve.If burnt member is respectively
Figure 560282DEST_PATH_IMAGE092
With
Figure DEST_PATH_IMAGE093
, and
Figure 778774DEST_PATH_IMAGE094
,
Figure DEST_PATH_IMAGE095
,
Figure 388878DEST_PATH_IMAGE096
, then
 
(12)
Wherein,
Figure 60031DEST_PATH_IMAGE098
.Formula(12)In, if
Figure DEST_PATH_IMAGE099
, then
Figure 780993DEST_PATH_IMAGE009
It is defined as a BPA function;If
Figure 791675DEST_PATH_IMAGE100
, then it is assumed that in the absence of orthogonal and
Figure 821948DEST_PATH_IMAGE009
, i.e., BPA can not be combined.
And the compositional rule of many belief functions is as follows:If
Figure DEST_PATH_IMAGE101
For same identification frameworkOn belief function,
Figure 442733DEST_PATH_IMAGE102
It is its corresponding elementary probability number, if
Figure DEST_PATH_IMAGE103
In the presence of and elementary probability number be
Figure 635817DEST_PATH_IMAGE009
, then
Figure 774674DEST_PATH_IMAGE104
 
(13)
Wherein
Figure DEST_PATH_IMAGE105
The reliability of data and the local diagnosis result of single evidence is only obtained according to existing sensor to construct the basic probability function of D-S evidence theory global diagnosis, the evidence that one of sensor is provided could be enabled to be merged with the evidence that other sensors are obtained, that is, the diagnostic result of CPN networks is converted into Evidence Reasoning Model.
Generally, the acquisition of Basic Probability As-signment relies on expertise, it is believed that the output valve of certain failure is big in CPN neutral net output vectors, then the probability that corresponding failure occurs is big.So the output valve of CPN neutral nets is used formula(14)Be normalized, be converted into should network various malfunctions basic probability assignment BPA, then according to the fusion rule of D-S evidence theory try to achieve its it is orthogonal and
Figure 905572DEST_PATH_IMAGE106
, the BPA of each state after as merging.
Figure 483184DEST_PATH_IMAGE001
Figure 275648DEST_PATH_IMAGE003
   
(14)
Formula(14)In,
Figure 585406DEST_PATH_IMAGE004
Represent the
Figure 452868DEST_PATH_IMAGE006
Individual evidence in CPN networks
Figure 506275DEST_PATH_IMAGE007
Individual output result;
Figure 346055DEST_PATH_IMAGE008
Represent
Figure 639764DEST_PATH_IMAGE006
Individual evidence is to state
Figure 197784DEST_PATH_IMAGE007
BPA.
When application D-S evidence theory carries out fusion diagnosis, using the result of the Steam Turbine Fault Diagnosis of synchronization as evidence body, merged in D-S Fusion Modules, obtain the fusion results judged current state, it is final to submit judging module, carry out the condition adjudgement of steam turbine failure.Through above-mentioned processing, whole observation judging process have passed through the fusion process from data-feature-knowledge, can be effectively prevented from the erroneous judgement of single differentiation or problem of failing to judge, reduce the error rate of fault diagnosis, it is ensured that the accuracy of fault diagnosis.
The present invention is by taking the oil whip failure of turbine rotor vibration simulation experiment platform as an example, the testing stand according to Fig. 1, exemplified by the frequency spectrum data for 1. 2. locating steam turbine oil whip vibration failure as measuring point with current vortex sensor 10 using photoelectric sensor 3 as measuring point, these data will by 0-0.39f, 0.4-0.49f, 0.5f, 0.51-0.59f, 1f, 2f, 3f, 3-5f,>5f(F is speed)Deng the amplitude components energy on 9 different frequency ranges as fault characteristic value, steam turbine oil whip vibration fault sample as shown in table 1.
Table 1
Figure DEST_PATH_IMAGE109
Fault data at two measuring points is diagnosed with CPN neutral nets, the fault diagnosis result for obtaining correspondence measuring point is as shown in table 2.
Table 2
Figure DEST_PATH_IMAGE111
According to formula(14)Data in table 2 are normalized, basic probability assignment BPA can be obtained as shown in table 3.Wherein defective space touches mill for axial direction
Figure 664669DEST_PATH_IMAGE112
, misalign
Figure DEST_PATH_IMAGE113
, turbine being utilized
Figure 686852DEST_PATH_IMAGE114
, it is uneven
Figure DEST_PATH_IMAGE115
, oil whirl
Figure 151462DEST_PATH_IMAGE116
, oil whip
Figure DEST_PATH_IMAGE117
.Because this six kinds of malfunctions are separate, so only needing to calculate the basic probability assignment of following six kinds of independent failures.
Table 3
Above-mentioned basic probability function is a kind of possibility description of failure, it is impossible to further accurate to judge, it is necessary to carry out evidence merging to above-mentioned basic probability function.Step is as follows:
1)Calculate conflict weights
Figure 806566DEST_PATH_IMAGE120
=1-[0.0235*(0.0072+0.0536+0.1263+0.0269+0.7610)+0.0047*(0.0250+0.0536+0.1263+0.0269+0.7610)+0.0883*(0.0250+0.0072+0.1263+0.0269+0.7610)+0.1366*(0.0250+0.0072+0.0536+0.0269+0.7610)+0.0227*(0.0250+0.0072+0.0536+0.1263+0.7610)+0.7242*(0.0250+0.0072+0.0536+0.1263+0.0269)]=0.5743
2)The basic probability function of each possible judgement is after merging:
=0.0235×0.025/0.5743≈0.0010
Figure 264092DEST_PATH_IMAGE122
=0.0047×0.0072/0.5743≈0.0001
Figure DEST_PATH_IMAGE123
=0.0883×0.0536/0.5743≈0.0082
=0.1366×0.1263/0.5743≈0.0300
Figure DEST_PATH_IMAGE125
=0.0227×0.0269/0.5743≈0.0011
Figure 776293DEST_PATH_IMAGE126
=0.7242×0.7610/0.5743≈0.9596
The output result of CPN neutral nets is after D-S evidence theory processing, and the comparison for obtaining final fusion results with CPN Neural Network Diagnosis result before merging is as shown in table 4.
Table 4
Figure 856375DEST_PATH_IMAGE128
To the diagnostic result of oil whip failure it is respectively 0.8714 and 0.9031 before can be seen that fusion from above-mentioned result of calculation, the observed result rises to 0.9596 after fusion, and the diagnostic value of other failures is then significantly declined before and after merging.As can be seen that the diagnostic result of two evidence bodies to 1. 2. being obtained with measuring point from measuring point is merged, it further enhancing to criterion
Figure 55275DEST_PATH_IMAGE117
Support so that the differentiation of each proposition is more obvious, is conducive to the differentiation to true proposition, realizes more accurate and reliable fault diagnosis.

Claims (1)

1. the integrated method for diagnosing faults of a kind of steam turbine based on CPN networks and D-S evidences, it is characterised in that method is comprised the following specific steps that:
1)It regard the Steam Turbine Vibration state parameter collected from sensor on turbine rotor vibration simulator stand as independent data sample, each independent CPN neutral nets are input to after the processing of feature extraction, processing and parameter normalization to be trained so that each independent CPN neutral nets can form failure symptom to the Nonlinear Mapping of fault mode;
2)Carried out using each independent CPN neutral nets after fault diagnosis, the output valve of CPN neutral nets be normalized using formula below, be converted into should CPN neutral nets various malfunctions basic probability assignment BPA,
Figure 2012100507549100001DEST_PATH_IMAGE002
Figure 2012100507549100001DEST_PATH_IMAGE004
Figure 2012100507549100001DEST_PATH_IMAGE006
  
Wherein
Figure 2012100507549100001DEST_PATH_IMAGE008
Represent the
Figure 2012100507549100001DEST_PATH_IMAGE010
Individual evidence in CPN networks
Figure 2012100507549100001DEST_PATH_IMAGE012
Individual output result;RepresentIndividual evidence is to state
Figure 686912DEST_PATH_IMAGE012
BPA;
3)Further data fusion is carried out to the diagnostic results of each failure CPN neutral nets according to the fusion rule of D-S evidence theory, try to achieve its it is orthogonal and
Figure 2012100507549100001DEST_PATH_IMAGE016
, the basic probability assignment of each status fault state, obtains fault diagnosis result after as merging.
CN2012100507549A 2012-03-01 2012-03-01 Integrated fault diagnostic method of steam turbine based on CPN (counter-propagation network) and D-S (dempster-shafer) evidences Pending CN102589890A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2012100507549A CN102589890A (en) 2012-03-01 2012-03-01 Integrated fault diagnostic method of steam turbine based on CPN (counter-propagation network) and D-S (dempster-shafer) evidences

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2012100507549A CN102589890A (en) 2012-03-01 2012-03-01 Integrated fault diagnostic method of steam turbine based on CPN (counter-propagation network) and D-S (dempster-shafer) evidences

Publications (1)

Publication Number Publication Date
CN102589890A true CN102589890A (en) 2012-07-18

Family

ID=46478836

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2012100507549A Pending CN102589890A (en) 2012-03-01 2012-03-01 Integrated fault diagnostic method of steam turbine based on CPN (counter-propagation network) and D-S (dempster-shafer) evidences

Country Status (1)

Country Link
CN (1) CN102589890A (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102928231A (en) * 2012-11-13 2013-02-13 上海电力学院 Equipment fault diagnosis method based on D-S (Dempster-Shafer) evidence theory
CN103207070A (en) * 2013-04-09 2013-07-17 苏州经贸职业技术学院 Method for diagnosing failure of rotary machine by fusing oil and vibration
CN103557884A (en) * 2013-09-27 2014-02-05 杭州银江智慧城市技术集团有限公司 Multi-sensor data fusion early warning method for monitoring electric transmission line tower
CN106447040A (en) * 2016-09-30 2017-02-22 湖南科技大学 Method for evaluating the health state of mechanical equipment based on heterogeneous multi-sensor data fusion
CN106503643A (en) * 2016-10-18 2017-03-15 上海电力学院 Tumble detection method for human body
CN107729920A (en) * 2017-09-18 2018-02-23 江苏海事职业技术学院 A kind of method for estimating state combined based on BP neural network with D S evidence theories
CN108318249A (en) * 2018-01-24 2018-07-24 广东石油化工学院 A kind of method for diagnosing faults of bearing in rotating machinery
CN108628968A (en) * 2018-04-24 2018-10-09 哈尔滨汽轮机厂有限责任公司 A kind of steam turbine measuring point historical data base method for building up
CN109583036A (en) * 2018-11-05 2019-04-05 中国航空工业集团公司西安飞机设计研究所 A kind of distribution method of the fault detection rate of integrated failure
CN109948636A (en) * 2017-12-21 2019-06-28 北京京东尚科信息技术有限公司 Data fusion method and device
CN111082402A (en) * 2019-12-31 2020-04-28 西安理工大学 Prediction method for cascading failure sequence of power transmission network
CN113033600A (en) * 2021-02-02 2021-06-25 湖南科技大学 Rotor misalignment state identification method based on improved D-S evidence fusion

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1389710A (en) * 2002-07-18 2003-01-08 上海交通大学 Multiple-sensor and multiple-object information fusing method
US20030103667A1 (en) * 2001-12-05 2003-06-05 New Mexico Technical Research Foundation Neural network model for compressing/decompressing image/acoustic data files
CN101539241A (en) * 2009-05-07 2009-09-23 北京航空航天大学 Hierarchical multi-source data fusion method for pipeline linkage monitoring network
US7613360B2 (en) * 2006-02-01 2009-11-03 Honeywell International Inc Multi-spectral fusion for video surveillance
CN101713776A (en) * 2009-11-13 2010-05-26 长春迪瑞实业有限公司 Neural network-based method for identifying and classifying visible components in urine
CN102175282A (en) * 2011-01-24 2011-09-07 长春工业大学 Method for diagnosing fault of centrifugal air compressor based on information fusion

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030103667A1 (en) * 2001-12-05 2003-06-05 New Mexico Technical Research Foundation Neural network model for compressing/decompressing image/acoustic data files
CN1389710A (en) * 2002-07-18 2003-01-08 上海交通大学 Multiple-sensor and multiple-object information fusing method
US7613360B2 (en) * 2006-02-01 2009-11-03 Honeywell International Inc Multi-spectral fusion for video surveillance
CN101539241A (en) * 2009-05-07 2009-09-23 北京航空航天大学 Hierarchical multi-source data fusion method for pipeline linkage monitoring network
CN101713776A (en) * 2009-11-13 2010-05-26 长春迪瑞实业有限公司 Neural network-based method for identifying and classifying visible components in urine
CN102175282A (en) * 2011-01-24 2011-09-07 长春工业大学 Method for diagnosing fault of centrifugal air compressor based on information fusion

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
彭文季等: "基于对向传播神经网络的水电机组振动故障诊断研究", 《西安理工大学学报》, vol. 22, no. 4, 31 December 2006 (2006-12-31), pages 366 *
徐春梅等: "基于改进D-S的汽轮机组集成故障诊断研究", 《系统仿真学报》, vol. 23, no. 10, 31 October 2011 (2011-10-31), pages 2191 - 2193 *

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102928231A (en) * 2012-11-13 2013-02-13 上海电力学院 Equipment fault diagnosis method based on D-S (Dempster-Shafer) evidence theory
CN103207070A (en) * 2013-04-09 2013-07-17 苏州经贸职业技术学院 Method for diagnosing failure of rotary machine by fusing oil and vibration
CN103207070B (en) * 2013-04-09 2015-08-26 苏州经贸职业技术学院 The rotary machinery fault diagnosis method that fluid merges mutually with vibration
CN103557884A (en) * 2013-09-27 2014-02-05 杭州银江智慧城市技术集团有限公司 Multi-sensor data fusion early warning method for monitoring electric transmission line tower
CN103557884B (en) * 2013-09-27 2016-06-29 杭州银江智慧城市技术集团有限公司 A kind of Fusion method for early warning of electric power line pole tower monitoring
CN106447040B (en) * 2016-09-30 2018-11-23 湖南科技大学 Mechanical equipment health state evaluation method based on Heterogeneous Multi-Sensor Data fusion
CN106447040A (en) * 2016-09-30 2017-02-22 湖南科技大学 Method for evaluating the health state of mechanical equipment based on heterogeneous multi-sensor data fusion
CN106503643A (en) * 2016-10-18 2017-03-15 上海电力学院 Tumble detection method for human body
CN106503643B (en) * 2016-10-18 2019-06-28 上海电力学院 Tumble detection method for human body
CN107729920A (en) * 2017-09-18 2018-02-23 江苏海事职业技术学院 A kind of method for estimating state combined based on BP neural network with D S evidence theories
CN109948636A (en) * 2017-12-21 2019-06-28 北京京东尚科信息技术有限公司 Data fusion method and device
CN108318249A (en) * 2018-01-24 2018-07-24 广东石油化工学院 A kind of method for diagnosing faults of bearing in rotating machinery
CN108318249B (en) * 2018-01-24 2020-04-17 广东石油化工学院 Fault diagnosis method for rotary mechanical bearing
CN108628968A (en) * 2018-04-24 2018-10-09 哈尔滨汽轮机厂有限责任公司 A kind of steam turbine measuring point historical data base method for building up
CN108628968B (en) * 2018-04-24 2022-06-21 哈尔滨汽轮机厂有限责任公司 Turbine measuring point historical database establishing method
CN109583036A (en) * 2018-11-05 2019-04-05 中国航空工业集团公司西安飞机设计研究所 A kind of distribution method of the fault detection rate of integrated failure
CN111082402A (en) * 2019-12-31 2020-04-28 西安理工大学 Prediction method for cascading failure sequence of power transmission network
CN111082402B (en) * 2019-12-31 2022-01-07 西安理工大学 Prediction method for cascading failure sequence of power transmission network
CN113033600A (en) * 2021-02-02 2021-06-25 湖南科技大学 Rotor misalignment state identification method based on improved D-S evidence fusion
CN113033600B (en) * 2021-02-02 2022-05-27 湖南科技大学 Rotor misalignment state identification method based on improved D-S evidence fusion

Similar Documents

Publication Publication Date Title
CN102589890A (en) Integrated fault diagnostic method of steam turbine based on CPN (counter-propagation network) and D-S (dempster-shafer) evidences
CN110276416B (en) Rolling bearing fault prediction method
CN107003663B (en) The monitoring of device with movable part
Xue et al. A fuzzy system of operation safety assessment using multimodel linkage and multistage collaboration for in-wheel motor
CN104200396B (en) A kind of wind turbine component fault early warning method
CN104850889B (en) Airplane rotation actuator drive unit adaptive fault detection, isolation and confidences assessment method
CN113092115B (en) Digital twin model construction method of digital-analog combined drive full-life rolling bearing
CN110308002A (en) A kind of municipal rail train suspension method for diagnosing faults based on ground detection
Xu et al. A bearing fault diagnosis method without fault data in new working condition combined dynamic model with deep learning
CN109583092A (en) A kind of intelligent machine diagnosis method for system fault of multi-level multi-mode feature extraction
CN105487009A (en) Motor fault diagnosis method based on k-means RBF neural network algorithm
CN106762343A (en) The diagnostic method of the hydraulic generator set thrust bearing failure based on online data
CN102609764A (en) CPN neural network-based fault diagnosis method for stream-turbine generator set
Shang et al. Fault diagnosis method of rolling bearing based on deep belief network
Zhang et al. Vibration-based structural damage detection via phase-based motion estimation using convolutional neural networks
CN112765890A (en) Dynamic domain adaptive network-based multi-working-condition rotating machine residual life prediction method
Guo et al. Reconstruction domain adaptation transfer network for partial transfer learning of machinery fault diagnostics
Chen et al. Rotor fault diagnosis system based on sGA-based individual neural networks
Zhou et al. Structural health monitoring of offshore wind power structures based on genetic algorithm optimization and uncertain analytic hierarchy process
Liu et al. Intelligent cross-condition fault recognition of rolling bearings based on normalized resampled characteristic power and self-organizing map
Rahimilarki et al. Time-series deep learning fault detection with the application of wind turbine benchmark
Yu et al. A new method for quantitative estimation of rolling bearings under variable working conditions
CN103245491A (en) Rotor system fault diagnosis method based on confirmed learning theory
Xing et al. Detection of magnitude and position of rotor aerodynamic imbalance of wind turbines using Convolutional Neural Network
Du et al. Research on the application of artificial intelligence method in automobile engine fault diagnosis

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C02 Deemed withdrawal of patent application after publication (patent law 2001)
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20120718