CN-115481567-B - Method and device for evaluating ablation quantity of breaker contact based on multidimensional information fusion

CN115481567BCN 115481567 BCN115481567 BCN 115481567BCN-115481567-B

Abstract

The invention discloses a method and a device for evaluating the ablation of a contact of a circuit breaker based on multidimensional information fusion, wherein in the method, each dimensional information in the action process of the circuit breaker is collected and preprocessed, wherein the multidimensional information is subjected to time scale alignment, sampling rate normalization and signal intensity normalization, the ablation of the contact is evaluated by adopting a characteristic fusion algorithm based on characteristic parameters, wherein the characteristic of energy in a time-frequency domain is extracted based on a vibration signal to be converted into the characteristic signal, the characteristic parameter is obtained based on the characteristic signal, and the measured data of the circuit breaker is evaluated based on the characteristic fusion algorithm to obtain the ablation of the contact.

Inventors

YANG AIJUN
CHU JIFENG
LI CHENHUI
WANG XIAOHUA
YUAN HUAN
RONG MINGZHE

Assignees

西安交通大学

Dates

Publication Date: 20260512
Application Date: 20220831

Claims (7)

1. A method for evaluating the ablation quantity of a breaker contact based on multidimensional information fusion is characterized by comprising the following steps, Step 100, acquiring each piece of dimension information in the action process of the circuit breaker, wherein each piece of dimension information comprises a vibration signal, an angular displacement signal, an opening and closing coil current signal, a loop fracture signal and a loop dynamic resistance signal; step 200, preprocessing the information of each dimension, wherein time scale alignment, sampling rate normalization and signal intensity normalization are performed on the information of each dimension, digital filtering processing is performed on the vibration signals, and a time-frequency domain transformation mode is adopted to convert the time-frequency domain signals into time-frequency domains; Step 300, based on the preprocessed characteristic extraction and characteristic value calibration of each dimension information, extracting a loop fracture signal to obtain a circuit breaker arc contact point and a corresponding main shaft angular displacement, extracting a loop dynamic resistance signal to obtain a main shaft angular displacement corresponding to a circuit breaker main contact point, marking the main shaft angular displacement corresponding to the main contact point, converting the main shaft angular displacement into a time domain, and converting the angular displacement of the arc contact point and the main contact point into a vibration signal; Step 400, evaluating the ablation of the contact by adopting a characteristic fusion algorithm based on the characteristic parameters, wherein the characteristic is obtained based on the characteristic signals by extracting time-frequency domain energy characteristics based on the vibration signals, and the ablation of the contact is obtained by evaluating the actually measured data of the circuit breaker based on the characteristic fusion algorithm, wherein the characteristic is obtained by extracting time-frequency domain energy characteristics based on the vibration signals and is converted into the characteristic signals: Wherein F (t) is a characteristic signal of the vibration signal, E f (t) is energy of a specific frequency band of the vibration signal at the time t, E total (t) is total energy of the vibration signal at the time t, and the characteristic parameters are obtained based on the obtained characteristic signal by the following steps: wherein F (t) is a characteristic signal of the vibration signal, For the energy of the specific frequency band of the vibration signal at the time t, And combining the characteristic parameters obtained by combining the two groups of signals along the time axis.
2. The method for evaluating the ablation amount of the breaker contact based on multi-dimensional information fusion according to claim 1, wherein in step S200, preferably, the sampling rate matching adopts an interpolation method, and the low sampling signal in each dimension information is linearly interpolated according to integer multiples to adapt to the high sampling rate signal of each dimension information.
3. The method for evaluating the ablation amount of the breaker contact based on the multi-dimensional information fusion according to claim 1, wherein in the step S200, the time-frequency domain transformation mode comprises S transformation, short-time fourier transformation, wavelet transformation.
4. The method for evaluating the ablation quantity of a breaker contact based on multi-dimensional information fusion according to claim 3, wherein in the S transformation, The successive S-transforms for the signal r (t) to be measured are: wherein t is signal sampling time, f is signal frequency, tau is a translation factor, r (t) is a signal to be detected, pi is a circumferential rate, e is a natural constant, j is an imaginary unit, and S is a continuous S conversion result; for the signal r (t) to be measured, its discrete S transforms into: wherein x is the time sampling point number at certain time intervals, y is the frequency sampling point number at certain frequency intervals, T is the sampling period, N is the sampling point number, R (k) is the discrete Fourier transform of the time sequence R (T), k is the frequency domain sampling point of the discrete Fourier transform, m is the intermediate variable of the calculation process, pi is the circumference rate, e is the natural constant, j is the imaginary number unit, and S is the discrete S transform result.
5. The breaker contact ablation amount evaluation method based on multidimensional information fusion according to claim 1, wherein the feature fusion algorithm comprises an ANN algorithm, an SVM algorithm, a KNN algorithm, an RVM algorithm, a deep learning neural network algorithm, a bayesian network algorithm.
6. The method for evaluating the contact ablation amount of a circuit breaker based on multidimensional information fusion according to claim 5, wherein in the RVM algorithm, the feature vector of the training sample is The target vector is The classification function model of RVM is: Wherein x is an input training sample set, x i is an ith training sample, n is the number of samples, ω is a weight vector, ω= [ ω 0 ,ω 1 ,...,ω n ] T ,ω i is an ith component of ω, ω 0 is an initial weight, y is a classifier output value, K (x, x i ) is a kernel function, an S function is introduced into a classification model, and P (t|ω) is set to obey bernoulli distribution, so that likelihood estimation probability is obtained as follows: Wherein, the probability function of P (t|omega) Bernoulli distribution, sigma (y) is the probability distribution function of S function, weight is obtained by maximum likelihood method under Bayesian framework, gaussian prior distribution is used Constraint parameters are defined for each weight to implement a smooth model, Wherein, eta= [ eta 0 ,η 1 ,...,η n ] T ] is n+1 dimension super parameter, and super parameter is introduced to each weight, thereby generating a sparse probability model; Initializing a super parameter eta; Establishing a Gaussian approximation to the posterior probability according to the likelihood estimation probability, obtaining an approximation to the edge likelihood, maximizing an approximate edge likelihood function, leading out re-estimation to the vector value of the super parameter, and repeating until the vector value of the super parameter converges; and predicting the data to be predicted according to the classification function model of the RVM to obtain a prediction result.
7. An apparatus for carrying out the method for evaluating the ablation amount of a breaker contact based on multi-dimensional information fusion according to any one of claims 1 to 6, characterized in that it comprises, A shock absorbing base supported on the ground; A hydraulic spring operating mechanism supported on the shock absorbing base; the opening and closing coil is arranged on the hydraulic spring operating mechanism; a circuit breaker connected to the opening/closing coil; an analog load controllably applied to the circuit breaker; a sensor interface module, which comprises, A voltage sensor connected with the opening and closing coil to measure a loop fracture signal, An angular displacement sensor provided to a main shaft of the circuit breaker to measure an angular displacement signal, A vibration sensor arranged on the opening and closing coil for measuring vibration signals, A current sensor connected to the opening and closing coil to measure an opening and closing coil current signal, A loop dynamic resistance measurement unit connecting the opening and closing coil and the circuit breaker to generate a loop dynamic resistance signal; the embedded acquisition module is connected with the sensor interface module to acquire and preprocess vibration signals, angular displacement signals, opening and closing coil current signals, loop fracture signals and loop dynamic resistance signals, and comprises an analog-to-digital converter, a digital isolator, a microcontroller for sampling control, a communication unit for signal transmission and storage and a storage unit; A cloud computing module communicatively coupled to the communication unit, the cloud computing module comprising, A feature extraction and feature value calibration unit for feature extraction and feature value calibration based on the preprocessed information of each dimension, And the evaluation algorithm deployment platform is connected with the feature extraction and feature value calibration unit to evaluate the ablation quantity of the contact by adopting a feature fusion algorithm.

Description

Method and device for evaluating ablation quantity of breaker contact based on multidimensional information fusion Technical Field The invention belongs to the technical field of GIS high-voltage circuit breaker contact electrical life assessment, and particularly relates to a circuit breaker contact ablation amount assessment method and device based on multidimensional information fusion. Background For the GIS high-voltage circuit breaker, arc extinction is completed by a contact system in the opening and closing process, the contact system is divided into a main contact and an arc contact, wherein the main contact is responsible for current carrying and adopts a material with better conductivity so as to reduce current carrying loss, and the arc contact is responsible for carrying an arc in opening and closing and adopts an ablation-resistant material. When the switch is closed, the arc contact contacts the main contact, the break voltage completes the predicted penetration on the arc contact, and after the arc contact contacts, the main contact contacts further to bear the current carrying function. Because the arc contact is worn under the ablation effect and gradually shortened after the arc contact is opened for a plurality of times, the arc cannot be effectively carried after the arc contact is ablated to a certain degree, and at the moment, the arc in the opening process can cause the ablation of the main contact, so that the function of the whole contact system is damaged. Therefore, it is of great practical importance to evaluate the extent of arcing contact ablation in a contact system. Arc energy is a critical factor in causing arc contact ablation, but is not easily measured. The current is usually used for evaluating the electric life, and mainly comprises an accumulated current breaking weighting method, an arcing time weighting evaluation method, an N-I b life curve method and the like. The dynamic resistance method can intuitively reflect the ablation condition of the arc contact in the arc extinguishing chamber of the circuit breaker by measuring the change of the resistance in the opening and closing process of the circuit breaker, but can only be measured when the circuit breaker is stopped, and cannot realize the on-line monitoring of the electric life. The above information disclosed in the background section is only for enhancement of understanding of the background of the invention and therefore may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Disclosure of Invention Aiming at the problems in the prior art, the invention provides a method and a device for evaluating the ablation quantity of a breaker contact based on multidimensional information fusion, which realize high-precision on-line monitoring of the electrical life of an arc contact. The invention aims to realize the technical scheme, and the method for evaluating the ablation quantity of the breaker contact based on multidimensional information fusion comprises the following steps: Step 100, acquiring each piece of dimension information in the action process of the circuit breaker, wherein each piece of dimension information comprises a vibration signal, an angular displacement signal, an opening and closing coil current signal, a loop fracture signal and a loop dynamic resistance signal; step 200, preprocessing the information of each dimension, wherein time scale alignment, sampling rate normalization and signal intensity normalization are performed on the information of each dimension, digital filtering processing is performed on the vibration signals, and a time-frequency domain transformation mode is adopted to convert the time-frequency domain signals into time-frequency domains; Step 300, based on the preprocessed characteristic extraction and characteristic value calibration of each dimension information, extracting a loop fracture signal to obtain a circuit breaker arc contact point and a corresponding main shaft angular displacement, extracting a loop dynamic resistance signal to obtain a main shaft angular displacement corresponding to a circuit breaker main contact point, marking the main shaft angular displacement corresponding to the main contact point, converting the main shaft angular displacement into a time domain, and converting the angular displacement of the arc contact point and the main contact point into a vibration signal; Step 400, evaluating the ablation of the contact by adopting a characteristic fusion algorithm based on the characteristic parameters, wherein the characteristic is obtained based on the characteristic signals by extracting time-frequency domain energy characteristics based on the vibration signals, and the ablation of the contact is obtained by evaluating the actually measured data of the circuit breaker based on the characteristic fusion algorithm, wherein the characteristic is obtained by extracting time-fr