Disclosure of Invention
The invention aims to provide a transformer magnetic biasing detection system and method based on digital twinning, which can utilize a digital twinning technology to establish a simulation transformer model in 3D MAX software according to transformer parameters, a magnetic field inductor, a current sensor, a temperature sensor, a vibration sensor and a noise detector are arranged on a transformer to respectively monitor the iron core magnetic field change information, the neutral point current information, the primary side current information, the secondary side current information, the temperature change information, the vibration information and the generated noise information of the transformer, the data information is fused together through a multi-sensor data fusion technology to jointly judge the magnetic biasing information of the transformer, the detected data information is transmitted to a monitoring center, the data information is automatically introduced into the simulation transformer model at the monitoring center to form the digital twinning transformer, the iron core magnetic field change information of the digital twinning transformer, the noise information of the digital twinning transformer and the like, The neutral point current information, the primary side current information, the secondary side current information, the temperature change information, the vibration information and the generated noise information are consistent with the information of the transformer and can be superposed on the digital twin transformer for display, a user can check the magnetic biasing information of the transformer and other characteristic changes caused by magnetic biasing through a computer end without frequently going to the site, and check the influence of the neutral point current on the magnetic biasing of the transformer and the influence of the magnetic biasing of the transformer on the transformer through the information superposed on the digital twin transformer.
In order to achieve the purpose, the invention adopts the technical scheme that: a transformer magnetic biasing detection method based on digital twinning comprises the following steps:
detecting iron core magnetic field change information, neutral point current information, primary side voltage information, primary side current information, secondary side current information, temperature change information, vibration information and generated noise information of a transformer through a sensor;
secondly, transmitting the detected data information to an industrial personal computer, carrying out signal amplification, filtering, AD conversion and data preprocessing on the acquired data information, and then remotely transmitting the preprocessed data information to a workstation;
thirdly, the workstation establishes a simulation transformer model according to transformer parameters through a digital twinning technology, and then introduces the preprocessed data information into the simulation transformer model to form a digital twinning transformer;
fusing iron core magnetic field change information, primary side current information, secondary side current information, temperature change information, vibration information and generated noise information together by a multi-sensor data fusion technology to judge magnetic biasing information of the transformer, and overlapping the magnetic biasing information on the digital twin transformer to be displayed through a workstation;
and fifthly, establishing a characteristic curve of the neutral point current and the magnetic field intensity of the iron core of the transformer in the workstation, superposing the characteristic curve between the neutral point current and the magnetic field intensity of the iron core on the digital twin transformer, and checking the influence of the neutral point current on the magnetic biasing of the transformer through the information superposed on the digital twin transformer.
Further, in the fourth step, the scheme for judging the magnetic biasing information of the transformer by the multi-sensor data fusion technology is as follows: the magnetic bias condition of the transformer can be judged by fusing parameter information such as iron core magnetic field change information, primary side current information, secondary side current information, temperature change information, vibration information, noise information and the like generated by the magnetic bias of the transformer, the magnetic bias condition of the transformer is detected by establishing a gradient data fusion model, a data fusion center is firstly set, wherein the sensor comprises a voltage sensor, a current sensor, a magnetic field inductor, a temperature sensor, a vibration sensor and a noise detector, the current sensor comprises a first current sensor and a second current sensor, wherein the first current sensor is used for detecting the primary side current information and the secondary side current information of the transformer, the second current sensor is used for detecting current information of a neutral point of the transformer, an intermediate station is arranged between the first current sensor, the magnetic field sensor, the temperature sensor, the vibration sensor, the noise detector and the data fusion center, data information collected by the first current sensor, the magnetic field sensor, the temperature sensor, the vibration sensor and the noise detector is correlated in the intermediate station, data level fusion is carried out, local fusion is achieved, feature extraction is carried out on the data information after the local fusion in the data fusion center, data attributes are judged according to feature extraction results, then the judged data information is correlated to carry out decision level fusion, global fusion is achieved, and the result after the fusion is output to judge the magnetic biasing condition of the transformer.
Furthermore, in the fifth step, after the second current sensor detects the current of the neutral point, the influence of the stray current on the magnetic biasing of the transformer is judged by comparing the current with data information collected by the magnetic field sensor.
Furthermore, in the process of judging the influence of the neutral point current on the magnetic bias of the transformer, the magnetic field sensor is used for detecting the change information of the magnetic field of the iron core, the neutral point current information and the change information of the magnetic field of the iron core, which are detected by the second current sensor and the magnetic field sensor, are transmitted to the workstation together, a characteristic curve of the neutral point current and the magnetic field strength of the iron core of the transformer is established in the workstation, the characteristic curve between the neutral point current and the magnetic field strength of the iron core of the transformer is superposed on the digital twin transformer, and when stray current enters the neutral point, the influence of the stray current of the neutral point on the magnetic bias of the transformer can be checked through the information superposed on the digital twin transformer.
Further, when a digital twin transformer is constructed in the third step, specific parameters of the transformer are led into BIM software Revit to generate RVT files, the RVT files are led into 3D max software to be edited, parts identical to BIM models are combined into an object according to element types in the 3D max software, redundant dot and line surfaces are deleted, the combined model is endowed with material textures and characteristic parameters, the edited model is led out from the 3D max software and loaded into an engine, secondary material effect adjustment is carried out according to the material attributes of the transformer, a virtual transformer with the same parameters as the transformer is rendered, a virtual industrial personal computer is established, and data information acquired by a voltage sensor, a current sensor, a magnetic field sensor, a temperature sensor, a vibration sensor and a noise detector is transmitted to the virtual industrial personal computer after being converged by the physical industrial personal computer, and establishing a data interface between the virtual industrial personal computer and the virtual transformer, performing data analysis and scene rendering in the virtual transformer according to the acquired data information, and finally generating a digital twin transformer so that the data information received by the digital twin transformer is consistent with the real characteristic data of the transformer.
Furthermore, in the data level fusion process of the data information collected by the first current sensor, the magnetic field sensor, the temperature sensor, the vibration sensor and the noise detector, the collected data information is locally fused by adopting a fuzzy logic control method, and X is used for fusing the collected data information1、X2、X3、X4、X5Respectively as fuzzy sets of a first current sensor, a magnetic field sensor, a temperature sensor, a vibration sensor and a noise detector, wherein X1The method comprises the primary side current information and the secondary side current information acquired by a first current sensor at each moment, wherein the primary side current information and the secondary side current information acquired at the kth moment are represented as x1(k);X2The magnetic field sensor comprises iron core magnetic field change information acquired at each moment of a magnetic field sensor, wherein the iron core magnetic field change information acquired at the kth moment is represented as x2(k);X3The temperature change information acquired at each moment of the temperature sensor is included, wherein the temperature change information acquired at the kth moment is represented as x3(k);X4The method comprises vibration information acquired at each moment of a vibration sensor, wherein the vibration information acquired at the kth moment is represented as x4(k);X5Including noise detector time of dayCollecting generated noise information at the kth moment, wherein the generated noise information collected at the kth moment is represented as x5(k) (ii) a Evaluation of X by closeness1、X2、X3、X4、X5The similarity of the magnetic biasing situation is identified, and at the kth moment, the data matrix among all sensors is as follows:
the elements in the matrix a are the expression of closeness between the sensors, that is:
α
mn(k) representing a proximity expression, x, between any two of the first current sensor, the magnetic field sensor, the temperature sensor, the vibration sensor, and the noise detector
m(k)、x
n(k) Respectively representing data information collected by the first current sensor, the magnetic field sensor, the temperature sensor, the vibration sensor and the noise detector at the time k, wherein when m is 1 and n is 2, x is
1(k) Representing data information, x, collected by the first current sensor at time k
2(k) Representing the data information collected by the magnetic field inductor at time k, when alpha
mn(k) When the value is less than the preset value M, considering x
m(k) And x
n(k) Are not similar, then alpha can be obtained
mn(k) When the value is 0, the following components are available:
the consistency measurement calculation formula of the sampling values of the first current sensor, the magnetic field inductor, the temperature sensor, the vibration sensor and the noise detector is as follows:
in the formula of alpha
ij(k) For the ith row and jth column of data information, alpha, of the sensor in the data matrix at time k
ij(k) Is x
1(k)、x
2(k)、x
3(k)、x
4(k) Or x
5(k)。
The calculation formula of data fusion is expressed as:
in the formula x
1(k) Expressed as data information, x, acquired by the first current sensor at time k
2(k) Expressed as data information, x, collected by the magnetic field sensor at time k
3(k) Expressed as data information, x, collected by the temperature sensor at time k
4(k) Expressed as data information, x, collected by the vibration sensor at time k
5(k) Expressed as data information, omega, collected by the noise detector at time k
i(k) The ith row weight in the data matrix is represented, and according to the information sharing principle, the sum of the information quantity of the optimal fusion estimation can be decomposed into the sum of the information quantities of a plurality of measurement data, namely, one information can be shared by a plurality of subsystems, wherein
Normalizing the fuzzy closeness of the first current sensor, the magnetic field inductor, the temperature sensor, the vibration sensor and the noise detector to obtain respective weights
In the formula, c
1(k),c
2(k),c
3(k),c
4(k),c
5(k) Representing a set of non-negative numbers.
Further, in the process of decision-level fusion in the data fusion center, the magnetic biasing situation of the transformer is divided into normal F1Mild degree of F2Severe F3Severe F4Four levels, let Θ be a recognition framework, Ω (Θ) represents the set of all subsets in Θ, and the transformer bias level is represented as:
Ω(Θ)={φ,{F1},{F2},{F3},{F4},{F1,F2},{F2,F3say, phi is an empty set, assuming Q ═ F1,F2E.g., theta, indicates that Q is either normal F1Either light F2I.e. Ω (Θ) is any one of the states;
after the recognition frame theta is determined, a set function G is defined, and omega (theta) is mapped to the interval [0,1 ]]The number of (a) above, expressed as:
wherein G (Q) is called basic probability assignment function, represents the confidence of the state recognition model to a specific state, and represents the mapping Bel on the recognition framework theta by using the belief function Bel, wherein Q is → [0,1]And satisfies the following conditions:
the next mapping Pl: Ω (Θ) → [0,1 ] is then represented by the plausibility function Pl]And satisfies:
in the formula Q
cRepresents the complement of Q, pl (Q) represents the plausibility of proposition Q, where pl (Q) 0 represents evidence rejection Q, and pl (Q) 1 represents evidence support Q;
let G
iA basic probability assignment function representing the ith set of evidence defined on the recognition framework Θ, where i ═ 1,2.
K represents the normalized coefficient, expressed as:
G
1(Q
i) As set 1 evidence Q
iBasic probability assignment function of G
2((Ω(Θ))
j) As the 2 nd evidence (omega (theta))
jG (q) reflects the degree of conflict between two evidences, and when K ≠ 0, represents the combination between the two sets of evidences in the form of an orthogonal sum; when K is 0, the condition that the orthogonal sum does not exist is shown, and the two evidences belong to a contradiction relation;
then a first current sensor, a magnetic field sensor, a temperature sensor, a vibration sensor and a noise sensor are constructedBasic probability assignment function of acoustic detector, and identification results of first current sensor, magnetic field sensor, temperature sensor, vibration sensor and noise detector as five evidences E
1、E
2、E
3、E
4、E
5While at the same time F is normal
1Mild degree of F
2Severe F
3Severe F
4Four grades are used as identification fields, and theta is equal to { F
1,F
2,F
3,F
4Form E
1、E
2、E
3、E
4、E
5A common identification framework, a basic probability assignment function of each evidence is constructed on the identification framework theta, and the basic probability assignment function is calculated according to a formula
Then E can be calculated
1、E
2、E
3、E
4、E
5The fused basic probability assignment function is used for judging the state of the magnetic biasing condition of the transformer according to the fused basic probability assignment function, for example, E is constructed on an identification frame theta
1As shown in table 1, where
sample 1 is analyzed and the maximum value of the basic probability assignment function of
sample 1 is at F
1And indicating that the bias condition of the transformer is in a normal state.
TABLE 1E1Basic probability assignment function of
Sample(s)
|
F1 |
F2 |
F3 |
F4 |
Sample classes
|
1
|
0.69
|
0.15
|
0.06
|
0.10
|
F 1 |
2
|
0.45
|
0.43
|
0.06
|
0.06
|
F 2 |
3
|
0.09
|
0.02
|
0.77
|
0.12
|
F 3 |
4
|
0.11
|
0.05
|
0.03
|
0.81
|
F4 |
The utility model provides a transformer magnetic biasing detecting system based on digit twin, which comprises a transformer, voltage sensor, current sensor, the magnetic field inductor, a weighing sensor and a temperature sensor, vibration sensor, the noise detector, the industrial computer, 5G module and workstation, install voltage sensor and current sensor on the transformer surface, voltage sensor, current sensor inserts the generating line of transformer respectively, the industrial computer is installed at the transformer surface, 5G module is installed on the industrial computer, install the magnetic field inductor by transformer core, temperature sensor, vibration sensor, the noise detector is installed at the transformer inboard, the magnetic field inductor, temperature sensor, vibration sensor, the noise detector, current sensor and voltage sensor connect the industrial computer respectively, the industrial computer passes through 5G module connection workstation.
Furthermore, the current sensors comprise six first current sensors and six second current sensors, the six first current sensors are respectively used for detecting the primary side current of the transformer and the secondary side current of the transformer, the one second current sensor is used for detecting the current of the neutral point of the transformer, and the three voltage sensors are used for detecting the primary side voltage of the bus of the transformer.
Compared with the prior art, the invention has the following beneficial effects: 1. the invention reflects the running condition of the transformer under the magnetic biasing condition by utilizing the digital twin technology, and transmits the iron core magnetic field change information, the neutral point current information, the primary side current information, the secondary side current information, the temperature change information, the vibration information and the generated noise information in the transformer to the digital twin transformer by adopting the 5G technology, so that the information of the digital twin transformer is consistent with the information of the transformer and can be superposed on the digital twin transformer for display, a user can check the magnetic biasing information of the transformer and other characteristic changes caused by magnetic biasing through a computer end without frequently going to the site, and check the influence of the neutral point current on the magnetic biasing of the transformer and the influence of the magnetic biasing of the transformer on the transformer by superposing the information on the digital twin transformer. The efficiency of fault monitoring is improved through analysis of the transformer simulation data. 2. The data information is fused together through a multi-sensor data fusion technology to judge the magnetic biasing information of the transformer, the system does not rely on the data information collected by one sensor alone to judge the magnetic biasing condition of the transformer, even if one sensor fails, the detection is not affected, and the identification accuracy is effectively improved. 3. The influence of the neutral point current on the magnetic biasing of the transformer is checked through information superposed on the digital twin transformer. The relation of stray current to the bias of the transformer can be corresponded, and particularly, for the transformer beside the rail transit, effective overhaul reference can be provided for workers.
Detailed Description
Referring to fig. 1 to 4, a method for detecting magnetic bias of a transformer based on digital twins includes the following steps:
detecting iron core magnetic field change information, neutral point current information, primary side voltage information, primary side current information, secondary side current information, temperature change information, vibration information and generated noise information of a transformer through a sensor;
secondly, transmitting the detected data information to an industrial personal computer 7, performing signal amplification, filtering, AD conversion and data preprocessing on the acquired data information, and remotely transmitting the preprocessed data information to a workstation;
thirdly, the workstation establishes a simulation transformer model according to the transformer parameters through a digital twinning technology, then leads the preprocessed data information into the simulation transformer model to form a digital twinning transformer,
fusing iron core magnetic field change information, primary side current information, secondary side current information, temperature change information, vibration information and generated noise information together by a multi-sensor data fusion technology to judge magnetic biasing information of the transformer, and overlapping the magnetic biasing information on the digital twin transformer to be displayed through a workstation; therefore, when the transformer magnetic biasing is judged, the transformer magnetic biasing condition is not judged by independently depending on data information collected by one sensor, and the identification accuracy is effectively improved;
and fifthly, establishing a characteristic curve of the neutral point current and the magnetic field intensity of the iron core of the transformer in the workstation, superposing the characteristic curve between the neutral point current and the magnetic field intensity of the iron core on the digital twin transformer, and checking the influence of the neutral point current on the magnetic biasing of the transformer through the information superposed on the digital twin transformer.
As shown in fig. 4, in the fourth step, the scheme for determining the magnetic bias information of the transformer by the multi-sensor data fusion technology is as follows: the magnetic bias condition of the transformer can be judged by fusing parameter information such as iron core magnetic field change information, primary side current information, secondary side current information, temperature change information, vibration information, noise information and the like generated by the magnetic bias of the transformer, a gradient data fusion model is established to detect the magnetic bias condition of the transformer, a data fusion center is set firstly, wherein the sensors comprise a voltage sensor 1, a current sensor 2, a magnetic field inductor 3, a temperature sensor 4, a vibration sensor 5 and a noise detector 6, the current sensor 2 comprises a first current sensor and a second current sensor, wherein the first current sensor is used for detecting the primary current information and the secondary current information of the transformer, the second current sensor is used for detecting the current information of the neutral point of the transformer, an intermediate station is arranged among the first current sensor, the magnetic field inductor 3, the temperature sensor 4, the vibration sensor 5, the noise detector 6 and the data fusion center, the data information collected by the first current sensor, the magnetic field sensor 3, the temperature sensor 4, the vibration sensor 5 and the noise detector 6 are correlated in the intermediate station, then data level fusion is carried out to realize local fusion, and the data information after the local fusion is carried out the feature extraction in the data fusion center, the data attribute is judged according to the feature extraction result, and then, associating the judged data information to perform decision-level fusion so as to realize global fusion, and outputting the fused result to judge the magnetic biasing condition of the transformer.
In the fifth step, after the second current sensor detects the current of the neutral point, the influence of the stray current on the magnetic biasing of the transformer is judged by comparing the current with the data information collected by the magnetic field inductor 3.
In the process of judging the influence of neutral point current on the bias magnetism of the transformer, the magnetic field sensor 3 is used for detecting iron core magnetic field change information, the neutral point current information and the iron core magnetic field change information detected by the second current sensor and the magnetic field sensor are transmitted to a workstation together, a characteristic curve of the neutral point current and the magnetic field intensity of the transformer iron core is established in the workstation, the characteristic curve between the neutral point current and the magnetic field intensity of the iron core is superposed on the digital twin transformer, when stray current is mixed into a neutral point, the influence of the neutral point stray current on the bias magnetism of the transformer can be checked through the information superposed on the digital twin transformer, the change of the magnetic field intensity of the iron core of the transformer along the rail transit is mainly checked when an locomotive passes through the transformer, and then the influence of the stray current on the bias magnetism of the transformer during the operation of the locomotive is obtained.
As shown in fig. 3, when constructing the digital twin transformer in the third step, the specific parameters of the transformer are first introduced into the BIM software Revit to generate an RVT file, the RVT file is introduced into the 3D max software to be edited, the same parts of the BIM model are combined into an object according to the element types in the 3D max software, redundant dot and line surfaces are deleted, the combined model is endowed with material texture and characteristic parameters, the edited model is exported from the 3D max software to be loaded into an engine, secondary material effect adjustment is performed according to the material property of the transformer, a virtual transformer having the same parameters as the transformer is rendered, a virtual industrial personal computer is established, and data information acquired by the voltage sensor 1, the current sensor 2, the magnetic field sensor 3, the temperature sensor 4, the vibration sensor 5 and the noise detector 6 is collected by the entity industrial computer 7 and then transmitted to the virtual industrial computer, and establishing a data interface between the virtual industrial personal computer and the virtual transformer, performing data analysis and scene rendering in the virtual transformer according to the acquired data information, and finally generating a digital twin transformer so that the data information received by the digital twin transformer is consistent with the real characteristic data of the transformer. And the data information collected by the voltage sensor 1 and the current sensor 2 for detecting the bus is also transmitted to the digital twin transformer, and meanwhile, the running voltage and current input by the digital twin transformer are consistent with those input by the transformer, so that the consistency of data in all aspects of the digital twin transformer and the transformer is ensured.
In the data level fusion process, the data information acquired by the first current sensor, the magnetic field inductor 3, the temperature sensor 4, the vibration sensor 5 and the noise detector 6 is locally fused by adopting a fuzzy logic control method, and the X is used for carrying out X fusion on the acquired data information1、X2、X3、X4、X5Respectively as a fuzzy set of a first current sensor, a magnetic field sensor 3, a temperature sensor 4, a vibration sensor 5, a noise detector 6, where X1The method comprises the primary current information and the secondary current information acquired by a first current sensor at each moment, wherein the primary current information and the secondary current information acquired at the kth moment are represented as x1(k);X2Comprises iron core magnetic field change information collected at each moment of the magnetic field inductor 3, wherein the iron core magnetic field change information collected at the kth moment is represented as x2(k);X3Comprises temperature change information collected at each moment of the temperature sensor 4, wherein the temperature change information collected at the kth moment is represented as x3(k);X4Comprises vibration information collected at each moment of the vibration sensor 5, wherein the vibration information collected at the kth moment is represented as x4(k);X5The noise detector 6 collects generated noise information at each moment, wherein the generated noise information collected at the kth moment is represented as x5(k) (ii) a Evaluation of X by closeness1、X2、X3、X4、X5The similarity of the magnetic biasing situation is identified, and at the kth moment, the data matrix among all sensors is as follows:
the elements in the matrix a are the expression of closeness between the sensors, that is:
α
mn(k) the expression of the proximity between any two sensors of the first current sensor, the magnetic field inductor, the temperature sensor, the vibration sensor and the noise detector is shown, x
m(k)、x
n(k) Respectively representing data information collected by the first current sensor, the magnetic field sensor, the temperature sensor, the vibration sensor and the noise detector at the time k, wherein when m is 1 and n is 2, x is
1(k) Representing data information, x, acquired by the first current sensor at time k
2(k) Representing the data information collected by the magnetic field inductor at time k, when alpha
mn(k) When the value is less than the preset value M, considering x
m(k) And x
n(k) Are not similar, then alpha can be obtained
mn(k) When the value is 0, the following components are available:
the consistency measurement calculation formula of the sampling values of the first current sensor, the
magnetic field inductor 3, the
temperature sensor 4, the vibration sensor 5 and the
noise detector 6 is as follows:
in the formula of alpha
ij(k) For the ith row and jth column of data information, alpha, of the sensor in the data matrix at time k
ij(k) Is x
1(k)、x
2(k)、x
3(k)、x
4(k) Or x
5(k)。
The calculation formula of data fusion is expressed as:
in the formula x
1(k) Expressed as data information, x, collected by the first current sensor at time k
2(k) Expressed as data information, x, collected by the magnetic field sensor at time k
3(k) Expressed as data information, x, collected by the temperature sensor at time k
4(k) Expressed as data information, x, collected by the vibration sensor at time k
5(k) Expressed as data information, omega, collected by the noise detector at time k
i(k) The ith row weight in the data matrix is represented, and according to the information sharing principle, the sum of the information quantity of the optimal fusion estimation can be decomposed into the sum of the information quantities of a plurality of measurement data, namely, one information can be shared by a plurality of subsystems, wherein
Normalizing the fuzzy closeness of the first current sensor, the magnetic field inductor, the temperature sensor, the vibration sensor and the noise detector to obtain respective weights
In the formula, c
1(k),c
2(k),c
3(k),c
4(k),c
5(k) Representing a set of non-negative numbers.
During decision-level fusion process of the data fusion center, the magnetic biasing situation of the transformer is divided into normal F1Mild degree of F2Severe F3Severe F4Four levels, let Θ be a recognition framework, Ω (Θ) represents the set of all subsets in Θ, and the transformer bias level is represented as:
Ω(Θ)={φ,{F1},{F2},{F3},{F4},{F1,F2},{F2,F3say, phi is an empty set, assuming Q ═ F1,F2E.g., theta, indicates that Q is either normal F1Either light F2I.e. Ω (Θ) is any one of the states;
after the recognition frame theta is determined, one is definedSet function G, mapping Ω (Θ) to the interval [0,1 ]]The number of (a) above, expressed as:
wherein G (Q) is called basic probability assignment function, represents the confidence of the state recognition model to a specific state, and represents the mapping Bel on the recognition framework theta by using the belief function Bel, wherein Q is → [0,1]And satisfies the following conditions:
the next mapping Pl: Ω (Θ) → [0,1 ] is then represented by the plausibility function Pl]And satisfies the following conditions:
in the formula Q
cRepresents the complement of Q, pl (Q) represents the plausibility of proposition Q, where pl (Q) 0 represents evidence rejection Q, and pl (Q) 1 represents evidence support Q;
let G
iA basic probability assignment function representing the ith set of evidence defined on the recognition framework Θ, where i ═ 1,2.
K represents the normalized coefficient, expressed as:
G
1(Q
i) As
set 1 evidence Q
iBasic probability assignment function of G
2((Ω(Θ))
j) As a 2 nd evidence (Ω (Θ))
jG (Q) reflects the degree of conflict between two evidences, and when K is not equal to 0, the combination between two sets of evidences is expressed in the form of orthogonal sum; when K is 0, the condition that the orthogonal sum does not exist is shown, and the two evidences belong to a contradiction relation;
then, basic probability assignment functions of the first current sensor, the
magnetic field inductor 3, the
temperature sensor 4, the vibration sensor 5 and the
noise detector 6 are constructed, and the first current sensor, the
magnetic field inductor 3, the
temperature sensor 4, the vibration sensor 5 and the noise areThe recognition result of the
detector 6 is used as five evidences E
1、E
2、E
3、E
4、E
5While normalizing F
1Mild degree of F
2Severe F
3Severe F
4Four grades are used as identification fields, and theta is equal to { F
1,F
2,F
3,F
4Form E
1、E
2、E
3、E
4、E
5A common identification framework, a basic probability assignment function of each evidence is constructed on the identification framework theta, and the basic probability assignment function is calculated according to a formula
Then E can be calculated
1、E
2、E
3、E
4、E
5The fused basic probability assignment function is used for judging the state of the transformer magnetic biasing situation according to the fused basic probability assignment function, for example, E is constructed on an identification frame theta
1As shown in table 1, where
sample 1 is analyzed and the maximum value of the basic probability assignment function of
sample 1 is at F
1And indicating that the bias condition of the transformer is in a normal state.
TABLE 1E1Basic probability assignment function of
Sample(s)
|
F1 |
F2 |
F3 |
F4 |
Sample classes
|
1
|
0.69
|
0.15
|
0.06
|
0.10
|
F 1 |
2
|
0.45
|
0.43
|
0.06
|
0.06
|
F 2 |
3
|
0.09
|
0.02
|
0.77
|
0.12
|
F 3 |
4
|
0.11
|
0.05
|
0.03
|
0.81
|
F4 |
Referring to fig. 1 and 2, a transformer magnetic bias detection system based on digital twins comprises a transformer, a voltage sensor 1, a current sensor 2, a magnetic field inductor 3, a temperature sensor 4, a vibration sensor 5, a noise detector 6, an industrial personal computer 7, a 5G module 8 and a workstation, wherein the voltage sensor 1 is installed on an inlet wire of a transformer bus, the voltage sensor 1 and the current sensor 2 are installed on the outer surface of the transformer, the voltage sensor 1 and the current sensor 2 are respectively connected to the transformer bus, the industrial personal computer 7 is installed on the outer surface of the transformer, the 5G module 8 is installed on the industrial personal computer 7, the magnetic field inductor 3 is installed beside a transformer core, the temperature sensor 4, the vibration sensor 5 and the noise detector 6 are installed on the inner side of the transformer, the magnetic field inductor 3, the temperature sensor 4, the vibration sensor 5, the noise detector 6, The current sensor 2 and the voltage sensor 1 are respectively connected with an industrial personal computer 7, and the industrial personal computer 7 is connected with the workstation through a 5G module 8.
The current sensors 2 comprise six first current sensors and six second current sensors, the six first current sensors are respectively used for detecting the primary side current of the transformer and the secondary side current of the transformer, the one second current sensor is used for detecting the current of the neutral point of the transformer, and the three voltage sensors 1 are used for detecting the primary side voltage of a bus of the transformer.
The working principle and the working process of the invention are as follows:
as shown in fig. 1 to 4, a voltage sensor 1 and a current sensor 2 are adopted to respectively collect voltage and current on a bus connected with a transformer, the voltage sensor 1, the current sensor 2, a magnetic field sensor 3, a temperature sensor 4, a vibration sensor 5 and a noise detector 6 transmit respective detected information to an industrial personal computer 7, the industrial personal computer 7 performs operations such as signal amplification, filtering, AD conversion, data preprocessing and the like on the collected data information, and controls a 5G module 8 to transmit data to a workstation through a 5G technology, a simulation transformer model is established in 3D MAX software through a digital twin technology in the workstation according to transformer parameters, the preprocessed data information is automatically introduced into the simulation transformer model to form a digital twin transformer, the data information received by the digital twin transformer is consistent with real characteristic data of the transformer, and then the magnetic field change information of the iron core, the primary current information, the secondary current information, the temperature change information, the vibration information and the generated noise information are fused together by a multi-sensor data fusion technology to jointly judge the magnetic biasing information of the transformer and are superposed on the digital twin transformer for display. The influence of the neutral point current on the magnetic biasing of the transformer is checked through information superposed on the digital twin transformer.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.