Phase state detection display method and device for double-contact circuit breaker

Abstract

The invention relates to the technical field of circuit breaker detection, in particular to a phase state detection display method and device of a double-contact circuit breaker. The method comprises the following steps: firstly, acquiring frequency data of mechanical actions, temperature data and current waveforms during opening and closing; further obtaining a mechanical wear coefficient according to the total frequency of the mechanical actions and the frequency of the recent mechanical actions; further analyzing the current waveform in the latest opening and closing process to obtain the current wave crest performance abnormality and the current fluctuation abnormality; the abnormal performance of the heating rate and the steady-state temperature is further analyzed, and the current temperature abnormal degree is obtained; and finally, detecting and displaying the state of the double-contact circuit breaker in combination with the current mechanical wear coefficient, the wave crest performance abnormality, the current fluctuation abnormality and the temperature abnormality. The gradual change degradation condition of the double-contact circuit breaker is comprehensively predicted from multiple angles of mechanical wear, current waveform abnormal performance and temperature abnormal performance, and the potential abnormal fault problem of the double-contact circuit breaker is identified in time.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breaker detection, and in particular to a method and device for detecting and displaying the phase state of a double-contact circuit breaker. Background Art

[0002] During phase detection in dual-contact circuit breakers, existing monitoring methods can only detect abnormal conditions when a critical fault occurs in the circuit breaker contacts, primarily including contact welding, complete disconnection, or current exceeding the limit. These faults are typically transient, allowing the monitoring system to respond promptly. However, these methods lack the ability to predict potential faults, particularly when detecting gradual degradation processes such as contact wear, oxidation, and contamination.

[0003] This limitation is particularly pronounced in complex operating conditions or scenarios requiring high reliability. For example, in high-load, safety-critical applications such as power systems and industrial automation, the inability to effectively and proactively identify progressive degradation failures can lead to serious equipment downtime, production interruptions, and even safety incidents. This not only compromises the long-term stability of the equipment but can also reduce overall system operational efficiency and lead to economic losses. Summary of the Invention

[0004] In order to solve the technical problem that existing detection methods cannot predict gradual degradation faults of dual-contact circuit breakers, the present invention aims to provide a method and device for detecting and displaying the phase state of a dual-contact circuit breaker. The technical solution adopted is as follows:

[0005] A method for detecting and displaying a phase state of a double-contact circuit breaker, the method comprising:

[0006] Obtain the number of mechanical action data, temperature data and current waveforms of the double-contact circuit breaker during opening and closing;

[0007] Obtain the mechanical wear coefficient for the current day based on the total number of mechanical actions before the current day and the frequency of mechanical actions per day within a preset historical neighborhood of the current day;

[0008] In the current waveform at the latest opening and closing time, the current peak performance abnormality is obtained based on the difference between the peak distribution and the preset normal peak distribution; the abnormal fluctuation period is screened out based on the dense distribution of extreme points; and the current current fluctuation abnormality is obtained based on the violent fluctuation of the current during the abnormal fluctuation period;

[0009] In the temperature data, the current temperature abnormality is obtained based on the difference between the heating rate and the preset normal heating rate, combined with the difference between the steady-state temperature and the preset normal steady-state temperature;

[0010] The state of the double-contact circuit breaker is detected and displayed in combination with the current mechanical wear coefficient, the peak performance abnormality, the current fluctuation abnormality, and the temperature abnormality.

[0011] Furthermore, the method for obtaining the peak performance abnormality includes:

[0012] Obtaining a trip peak abnormality coefficient based on a difference characteristic between a first large current peak value and a second large current peak value in the current waveform at the time of the latest trip; the difference characteristic between the first large current peak value and the second large current peak value is positively correlated with the trip peak abnormality coefficient;

[0013] Obtaining a closing peak abnormality coefficient according to a difference between a ratio of a first maximum current peak value to a second maximum current peak value in the current waveform at the time of latest closing and a preset normal ratio;

[0014] The opening peak abnormality coefficient and the closing peak abnormality coefficient are integrated to obtain the current peak performance abnormality.

[0015] Furthermore, the method for obtaining the abnormal fluctuation period includes:

[0016] In the current waveform at the latest trip, the time differences between adjacent extreme value points are obtained and time sequence numbers are obtained in a time sequence order; the time differences are arranged from small to large to form a time difference sorting sequence, the time difference sorting sequence is divided at the maximum element value of the first-order difference sequence of the time difference sorting sequence, and in a section of the time difference sorting sequence to which the smallest time difference belongs, the time period of the extreme value points corresponding to the time differences with consecutive time sequence numbers is used as the abnormal fluctuation period at the latest trip;

[0017] Obtain the abnormal fluctuation period during the latest closing operation; the method for obtaining the abnormal fluctuation period during the latest closing operation is similar to the method for obtaining the abnormal fluctuation period during the latest opening operation.

[0018] Furthermore, the method for obtaining the current fluctuation abnormality includes:

[0019] Obtain the fluctuation intensity coefficient of the current value at the extreme point within each abnormal fluctuation period; combine the fluctuation intensity coefficient corresponding to the abnormal fluctuation period at the latest opening and the fluctuation intensity coefficient corresponding to the abnormal fluctuation period at the latest closing to obtain the current current fluctuation abnormality; the fluctuation intensity coefficient is positively correlated with the current fluctuation abnormality.

[0020] Furthermore, the method for detecting and displaying the state of a double-contact circuit breaker includes:

[0021] fusing the current mechanical wear coefficient, the peak performance abnormality, and the current fluctuation abnormality to obtain a first abnormality coefficient; the mechanical wear coefficient, the peak performance abnormality, and the current fluctuation abnormality are all positively correlated with the first abnormality coefficient;

[0022] fusing the current mechanical wear coefficient and the temperature anomaly to obtain a second anomaly coefficient; the mechanical wear coefficient is negatively correlated with the second anomaly coefficient; and the temperature anomaly is positively correlated with the second anomaly coefficient;

[0023] The first abnormality coefficient and the second abnormality coefficient are integrated to obtain the current abnormal state coefficient of the double-contact circuit breaker; whether the double-contact circuit breaker is in an abnormal state is determined according to the abnormal state coefficient, and the current state of the double-contact circuit breaker is displayed.

[0024] Furthermore, when the abnormal state coefficient is greater than a preset abnormal threshold, it is determined that the state of the double-contact circuit breaker is abnormal, and a fault light is turned on.

[0025] Furthermore, the method for obtaining the mechanical wear coefficient includes:

[0026] The ratio of the total number of mechanical actions before the current day to the preset theoretical total number of mechanical actions is used as the first mechanical wear parameter of the current day;

[0027] Obtaining a second mechanical wear parameter for the current day based on a proportional relationship between the number of mechanical actions per day within the preset historical neighborhood and the maximum number of mechanical actions per day in the historical days;

[0028] The first mechanical wear parameter and the second mechanical wear parameter are integrated to obtain a mechanical wear coefficient for the current day; the first mechanical wear parameter and the second mechanical wear parameter are both positively correlated with the mechanical wear coefficient.

[0029] Furthermore, the method for obtaining the fluctuation intensity coefficient includes:

[0030] The standard deviation of the current value at the extreme point in each abnormal fluctuation period is linearly normalized and used as the corresponding fluctuation intensity coefficient.

[0031] Furthermore, the preset historical neighborhood is the most recent 7 days.

[0032] The present invention also proposes a phase state detection and display device for a double-contact circuit breaker, the device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements any one of the steps of the phase state detection and display method for a double-contact circuit breaker.

[0033] The present invention has the following beneficial effects:

[0034] The present invention first obtains the number of mechanical action data, temperature data and current waveforms during opening and closing of the double-contact circuit breaker, providing a data basis for subsequent detection of the gradual degradation of the double-contact circuit breaker; further obtains the mechanical wear coefficient of the current day, characterizes the mechanical wear intensity of the double-contact circuit breaker, and predicts the gradual degradation of mechanical wear, providing a basis for subsequent evaluation of the working state of the double-contact circuit breaker; further, in the current waveform during the latest opening and closing, evaluates the abnormal performance characteristics of the current from the perspective of peak distribution abnormality, and obtains the current peak performance abnormality; further, based on the violent fluctuation of the current during the abnormal fluctuation period with dense distribution of extreme points, obtains the current current fluctuation abnormality The system evaluates the abnormal current characteristics from the perspective of abnormal current fluctuations, providing a basis for subsequent evaluation of the working status of the dual-contact circuit breaker. Furthermore, based on the difference between the heating rate and the preset normal heating rate, combined with the difference between the steady-state temperature and the preset normal steady-state temperature, the current temperature anomaly is obtained. The thermal state anomaly of the circuit breaker is comprehensively evaluated from both dynamic and static dimensions to detect gradual degradation faults such as contact oxidation, loosening, or deterioration of the heat dissipation system in advance, providing more basis for subsequent evaluation of the working status of the dual-contact circuit breaker. Finally, the dual-contact circuit breaker status is detected and displayed by combining the current mechanical wear coefficient, peak performance abnormality, current fluctuation abnormality, and temperature abnormality. The system comprehensively predicts the gradual degradation of the dual-contact circuit breaker from multiple perspectives, including mechanical wear, abnormal current waveform performance, and abnormal temperature performance, allowing for timely identification of potential abnormal faults in the dual-contact circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 A flow chart of a method for detecting and displaying the phase state of a double-contact circuit breaker provided by one embodiment of the present invention;

[0037] Figure 2 A schematic structural diagram of a double-contact circuit breaker provided by one embodiment of the present invention;

[0038] Figure 3 A current waveform diagram of the opening and closing coils of a double-contact circuit breaker under normal conditions provided by one embodiment of the present invention;

[0039] Figure 4 An abnormal current waveform diagram provided by an embodiment of the present invention.

[0040] The numbers in the figure are: 1. handle; 2. connecting rod; 3. housing; 4. trip coil; 5. wiring screw; 6. arc extinguishing chamber; 7. magnetic blow coil. DETAILED DESCRIPTION

[0041] To further illustrate the technical means and effectiveness of the present invention in achieving its intended objectives, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effectiveness of a method and device for detecting and displaying the phase state of a dual-contact circuit breaker according to the present invention. In the following description, references to "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0042] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0043] The following describes in detail a method and device for detecting and displaying the phase state of a double-contact circuit breaker provided by the present invention with reference to the accompanying drawings.

[0044] See also Figure 1 , which shows a flow chart of a method for detecting and displaying the phase state of a double-contact circuit breaker provided by one embodiment of the present invention, specifically comprising:

[0045] Step S1: Acquire the number of mechanical action data, temperature data, and current waveforms during opening and closing of the double-contact circuit breaker.

[0046] Considering that the service life of the double-contact circuit breaker will be affected by mechanical wear, and the temperature during normal operation and the current waveform during opening and closing have certain normal patterns, the number of mechanical action data, temperature data and current waveform during opening and closing of the double-contact circuit breaker are obtained to provide a data basis for subsequent detection of the gradual degradation of the double-contact circuit breaker.

[0047] In one embodiment of the present invention, the number of mechanical actions is obtained through the micro switch of the double-contact circuit breaker; the current data is obtained through the high-precision current sensor of the double-contact circuit breaker (sampling rate ≥ 10kHz), and the current data during opening and closing are intercepted to obtain the current waveform of the opening and closing coil; and the temperature data is obtained through the NTC thermistor.

[0048] The current waveform of the opening and closing coil refers to the dynamic curve of the current flowing through the electromagnetic operating coil of a high-voltage circuit breaker as it changes over time during opening (opening the circuit) or closing (closing the circuit). This waveform can be captured by a high-sampling-rate sensor to reflect the real-time status of the circuit breaker's mechanical operating mechanism, electromagnetic system, and control circuit.

[0049] See also Figure 2 , which shows a structural schematic diagram of a double-contact circuit breaker provided by an embodiment of the present invention; the numbers in the figure are: 1 handle; 2 connecting rod; 3 housing; 4 tripping coil; 5 wiring screw; 6 arc extinguishing chamber; 7 magnetic blow coil; 1 handle is used to manually control the circuit breaker, and the operating force is transmitted through 2 connecting rods to control the contacts; 3 housing is used to fix internal components; 4 tripping coil is the core of the circuit breaker's protection device. When the circuit is overloaded or short-circuited, the coil is energized to generate electromagnetic force, driving the tripping mechanism to operate, forcing the contacts to separate and cut off the circuit; 5 wiring screws are used to fix external load lines and power lines; 6 arc extinguishing chamber is a key component for extinguishing the arc generated when the contacts are disconnected. The magnetic field generated by 7 magnetic blow coil assists the arc to enter the 6 arc extinguishing chamber, eliminating the arc energy.

[0050] Double-contact circuit breakers typically consist of main contacts and arcing contacts. Their design allows current to pass through two independent contact systems, enabling double-contact circuit breakers to achieve higher switching capabilities under high current conditions.

[0051] The main contacts are used to conduct normal working current, have low contact resistance, and are mostly made of silver-based alloys; the arc contacts are used to withstand arc erosion when breaking fault currents, and are made of high-temperature resistant materials (such as copper-tungsten alloy).

[0052] When power is on: the current forms a circuit through the main contact and the arc contact. When the current passes through the arc contact, an arc is generated, which helps to maintain the conduction of the current.

[0053] When power is off: When an overload or short circuit is detected, the bimetallic strip or other tripping mechanism will act quickly to separate the moving contact from the static contact and cut off the circuit.

[0054] Step S2: Obtain the mechanical wear coefficient of the current day based on the total number of mechanical actions before the current day and the frequency of mechanical actions per day within a preset historical neighborhood of the current day.

[0055] As the number of mechanical actions accumulates, spring fatigue, oxidation and damage to the contact surface will occur, leading to material performance loss and deformation, and the performance shows a gradual degradation trend. Therefore, the total number of mechanical actions before the current day reflects the mechanical wear characteristics; considering that the frequency of mechanical actions in the recent period reflects the frequent start and stop of loads and the frequent overload or short-circuit events, it also reflects the mechanical wear characteristics of the circuit breaker. Therefore, the mechanical wear coefficient of the current day is obtained in combination with the frequency of mechanical actions per day in the preset historical neighborhood of the current day to characterize the mechanical wear intensity of the double-contact circuit breaker, so as to predict the gradual degradation of mechanical wear and provide a basis for the subsequent evaluation of the working status of the double-contact circuit breaker.

[0056] Preferably, in one embodiment of the present invention, considering that a mechanical structure has a theoretical service life, a double-contact circuit breaker also has a theoretical number of mechanical actions. The greater the total number of mechanical actions performed before the current day is compared to the theoretical value, the more serious the mechanical wear. Therefore, the ratio of the total number of mechanical actions before the current day to the preset theoretical total number of mechanical actions is used as the first mechanical wear parameter for the current day.

[0057] Considering that the greater the number of mechanical actions on a certain day is compared to the maximum number of mechanical actions in a single day, it means that the mechanical actions on that day are more frequent and the mechanical wear is more serious. Therefore, the second mechanical wear parameter of the current day is obtained based on the ratio between the number of mechanical actions per day in the preset historical neighborhood and the maximum number of mechanical actions per day in the historical day;

[0058] The first mechanical wear parameter and the second mechanical wear parameter are integrated to obtain the mechanical wear coefficient of the current day; both the first mechanical wear parameter and the second mechanical wear parameter are positively correlated with the mechanical wear coefficient.

[0059] As an example, the preset historical neighborhood is the latest 7 days before the current day; the preset theoretical total number of mechanical actions of the double-contact circuit breaker is obtained through the product manual or laboratory data;

[0060] For each of the 7 days before the current day, the ratio of the number of mechanical actions in one day to the maximum number of mechanical actions in a single day is used as the second wear sub-parameter. All the second wear sub-parameters of the 7 days are accumulated and linearly normalized to form the second mechanical wear parameter. The product of the first mechanical wear parameter and the second mechanical wear parameter is used as the mechanical wear coefficient of the current day.

[0061] The number of mechanical actions per day represents the frequency of the mechanical actions per day; and the first mechanical wear parameter and the second mechanical wear parameter are fused by multiplication.

[0062] In another embodiment of the present invention, considering that the more mechanical actions occur in a day, the larger the second wear sub-parameter is, indicating that the mechanical actions on that day are more frequent, the product of the second wear sub-parameter and the number of mechanical actions for each of the 7 days before the current day can be used as the frequency of mechanical actions for each day; the frequency of all mechanical actions for 7 days is accumulated and linearly normalized to obtain the second mechanical wear parameter.

[0063] In other embodiments of the present invention, the implementer may also fuse the first mechanical wear parameter and the second mechanical wear parameter by addition or weighted summation to obtain the mechanical wear coefficient.

[0064] Step S3: In the latest current waveform during opening and closing, obtain the current peak performance abnormality based on the difference between the peak distribution and the preset normal peak distribution; filter out the abnormal fluctuation period based on the dense distribution of extreme points; and obtain the current current fluctuation abnormality based on the violent fluctuation of the current during the abnormal fluctuation period.

[0065] By analyzing and capturing the transient characteristics of the current waveform of the opening and closing coils of double-contact circuit breakers, we can identify abnormal fault conditions such as operating mechanism jamming (waveform distortion), electromagnet residual magnetism (current tailing), or coil turn-to-turn short circuits (abnormal amplitude), and analyze the gradual degradation of double-contact circuit breakers from the perspective of current waveform performance.

[0066] Please participate Figure 3 , which shows a current waveform of a double-contact circuit breaker opening and closing coil under normal conditions provided by one embodiment of the present invention; Figure 3 In the figure, the horizontal axis is the time axis and the vertical axis is the current value axis. The left side corresponds to the coil current waveform when opening, with a time length of 40ms; the right side corresponds to the coil current waveform when closing, with a time length of 80ms; when analyzing the current waveform of a double-contact circuit breaker, the opening current waveform is intercepted 40ms after opening, and the closing current waveform is intercepted 80ms after closing.

[0067] The peak distribution of the current waveform of a double-contact circuit breaker under normal conditions has a relatively fixed distribution pattern. Therefore, in the current waveform during the latest opening and closing operation, the current peak performance abnormality is obtained based on the difference between the peak distribution and the preset normal peak distribution. The abnormal performance characteristics of the current are evaluated from the perspective of the peak distribution abnormality, providing a basis for subsequent evaluation of the working status of the double-contact circuit breaker.

[0068] Preferably, in one embodiment of the present invention, the maximum point of the current value is regarded as a peak, and the peaks are sorted according to the size of the maximum point; Figure 3 In the example, the first maximum current peak value and the second maximum current peak value during opening are kept close to each other, and the first maximum current peak value is greater than the second maximum current peak value during closing, and the second maximum current peak value is generally about half of the first maximum current peak value. Therefore, the preset normal peak distribution includes: the first maximum current peak value and the second maximum current peak value are close to each other during opening, and the preset normal ratio of the first maximum current peak value and the second maximum current peak value during closing;

[0069] Since the preset normal peak distribution corresponding to opening is that the first and second largest current peaks are similar, the difference is zero when the arc extinguishing efficiency and contact operation are fully coordinated. Since the difference between the two data and the ideal difference of 0 is equivalent to the difference between the two data themselves, for example, |A-0|=|A|, where A represents the difference between the first and second largest current peaks, the difference between the first and second largest current peaks in the current waveform at the latest opening reflects the difference between the peak distribution at opening and the preset normal peak distribution.

[0070] Based on this, the tripping peak abnormality coefficient is obtained according to the difference characteristics of the first and second largest current peak values ​​in the current waveform at the time of the latest tripping; the difference characteristics of the first and second largest current peak values ​​are positively correlated with the tripping peak abnormality coefficient;

[0071] Obtaining a closing peak abnormality coefficient based on a difference between a ratio of a first current peak value to a second current peak value in a current waveform at the time of latest closing and a preset normal ratio;

[0072] The abnormal coefficient of the opening peak and the abnormal coefficient of the closing peak are integrated to obtain the abnormal degree of the current peak performance.

[0073] As an example, the absolute value of the difference between the first largest current peak value (current value) and the second largest current peak value (current value) is linearly normalized and used as the trip peak abnormality coefficient; the difference characteristics of the first largest current peak value and the second largest current peak value are expressed in the form of the absolute value of the difference.

[0074] The ratio of the first maximum current peak value to the second maximum current peak value at closing under normal circumstances is used as the preset normal ratio; the absolute value of the difference between the ratio of the first maximum current peak value to the second maximum current peak value in the current waveform at the latest closing and the preset normal ratio is linearly normalized, and the normalized result is used as the closing peak abnormality coefficient; the difference between the ratio of the first maximum current peak value to the second maximum current peak value in the current waveform at the latest closing and the preset normal ratio is expressed in the form of the absolute value of the difference, where the first maximum current peak value is in the numerator position when calculating the ratio.

[0075] Finally, the average of the opening peak abnormality coefficient and the closing peak abnormality coefficient is used as the peak performance abnormality to characterize the abnormality of the opening and closing coil current performance of the current double-contact circuit breaker.

[0076] See also Figure 4 , which shows an abnormal current waveform diagram provided by an embodiment of the present invention; Figure 4The figure shows the abnormal current fluctuations at different stages (roughly divided into the front, middle and back stages) during opening and closing, which correspond to fault manifestations such as iron core jamming and locking mechanism defects.

[0077] from Figure 4 It can be seen from the figure that when abnormal current fluctuation occurs in the double-contact circuit breaker, there are densely distributed current extreme points, and the current in these abnormal periods shows violent fluctuations. Therefore, the abnormal fluctuation period is screened out based on the dense distribution of extreme points; based on the violent current fluctuations in the abnormal fluctuation period, the current fluctuation abnormality is obtained, and the abnormal performance characteristics of the current are evaluated from the perspective of abnormal current fluctuations, providing a basis for the subsequent evaluation of the working status of the double-contact circuit breaker.

[0078] Preferably, in one embodiment of the present invention, considering that the more dense the extreme value points are, the smaller the time difference between adjacent extreme value points is, the time difference between adjacent extreme value points in the current waveform at the latest trip is obtained and a time sequence number is obtained in a time sequence order; the time differences are arranged from small to large to form a time difference sorting sequence, and the time difference sorting sequence is used to analyze the dense distribution of the extreme value points;

[0079] Considering that the maximum value of the first-order difference calculated for the time difference sorting sequence corresponds to a significant jump point in the time difference distribution, reflecting the transition of the extreme value point density from sparse to dense, the time difference sorting sequence is divided at the maximum element value of the first-order difference sequence of the time difference sorting sequence. In a time difference sorting sequence to which the minimum time difference belongs, the time period of the extreme value point corresponding to the time difference with consecutive time sequence numbers is taken as the abnormal fluctuation period when the latest tripping occurs;

[0080] Obtain the abnormal fluctuation period during the latest closing operation; the method for obtaining the abnormal fluctuation period during the latest closing operation is similar to the method for obtaining the abnormal fluctuation period during the latest opening operation.

[0081] Specifically, in the current waveform at the latest closing time, the time difference between adjacent extreme value points is obtained and the timing sequence number is obtained in a time sequence order; the time difference is arranged from small to large to form a time difference sorting sequence, and the time difference sorting sequence is divided at the maximum element value of the first-order difference sequence of the time difference sorting sequence; in a time difference sorting sequence to which the minimum time difference belongs, the time period of the extreme value point corresponding to the time difference with consecutive timing sequence numbers is used as the abnormal fluctuation period at the latest closing time.

[0082] For example, there are 13 extreme points, and 12 time differences are obtained, numbered [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]. After sorting and dividing the time difference sorted sequence, the obtained values ​​are [1, 3, 4, 5, 6, 10, 12] and [2, 7, 8, 9, 11]. The smallest time difference is 5. Therefore, in the corresponding sequence [1, 3, 4, 5, 6, 10, 12], the time differences with sequence numbers [3, 4, 5, 6] are continuous, corresponding to the extreme points with sequence numbers [3, 4, 5, 6, 7]. The time period between the extreme points with sequence numbers 3 to 7 is regarded as the abnormal fluctuation period.

[0083] In other embodiments of the present invention, a time difference threshold may be set, and the time difference sorting sequence may be divided when the time difference is greater than or equal to the time difference threshold for the first time.

[0084] Preferably, in one embodiment of the present invention, considering that the extreme point is a point where the current changes significantly during the abnormal fluctuation period, the characteristics of the current fluctuation at the extreme point are analyzed to represent the severe fluctuation of the current during the abnormal fluctuation period.

[0085] Based on this, the fluctuation intensity coefficient of the current value at the extreme point in each abnormal fluctuation period is obtained; the fluctuation intensity coefficient corresponding to the abnormal fluctuation period at the latest opening and the fluctuation intensity coefficient corresponding to the abnormal fluctuation period at the latest closing are integrated to obtain the current current fluctuation abnormality; the fluctuation intensity coefficient is positively correlated with the current fluctuation abnormality.

[0086] As an example: the standard deviation of the current value at the extreme point in each abnormal fluctuation period is linearly normalized and used as the corresponding fluctuation severity coefficient; the average of the fluctuation severity coefficient at the latest opening and the fluctuation severity coefficient at the latest closing is used as the current fluctuation abnormality.

[0087] It should be noted that when there are multiple abnormal fluctuation periods in the latest opening or closing, for example, there are three abnormal fluctuation periods during opening, the fluctuation severity coefficients of these three abnormal fluctuation periods are obtained respectively, and finally the average of the three fluctuation severity coefficients is used as the fluctuation severity coefficient at the latest opening.

[0088] In other embodiments of the present invention, the fluctuation severity coefficient of all current values ​​in each abnormal fluctuation period can also be obtained to obtain the current fluctuation abnormality; one or more parameters that measure the severe fluctuation of data, such as the variance, standard deviation, range, mean absolute deviation, etc. of the current value can be added or multiplied to obtain the fluctuation severity coefficient. This is a technical means well known to those skilled in the art and will not be repeated here.

[0089] Step S4: in the temperature data, according to the difference between the heating rate and the preset normal heating rate, combined with the difference between the steady-state temperature and the preset normal steady-state temperature, the current temperature abnormality is obtained.

[0090] Considering that in double-contact circuit breakers, temperature anomalies are usually closely related to faults such as contact resistance changes, overload, poor heat dissipation or contact aging; when the contacts gradually oxidize and wear, causing poor contact, or dust accumulates in the cooling system, the fan fails or the ambient temperature is too high, resulting in insufficient heat dissipation performance, or when overloaded, the heating rate and steady-state temperature will gradually deviate from the normal values. Therefore, in the temperature data, the current temperature anomaly degree is obtained based on the difference between the heating rate and the preset normal heating rate, combined with the difference between the steady-state temperature and the preset normal steady-state temperature.

[0091] By analyzing the difference between the heating rate and steady-state temperature and the preset normal values, the thermal state anomaly of the circuit breaker can be comprehensively evaluated from both dynamic and static dimensions, so as to detect gradual degradation faults such as contact oxidation, loosening or deterioration of the heat dissipation system in advance, providing more basis for the subsequent evaluation of the working status of the double-contact circuit breaker.

[0092] Preferably, in one embodiment of the present invention, first, a temperature rise curve of the contact is obtained under rated current, and the initial temperature before heating and the steady-state temperature after heating (at thermal equilibrium) are obtained. Based on the heating time, the ratio of the difference between the steady-state temperature and the initial temperature to the heating time is used as the heating rate to obtain the preset normal heating rate and the preset normal steady-state temperature.

[0093] The same method is used to obtain the current steady-state temperature and heating rate of the contact;

[0094] Considering that the higher the current steady-state temperature is compared with the normal value and the higher the heating rate is compared with the normal value, the more abnormal the contact operation is, so the difference between the current steady-state temperature and the preset normal steady-state temperature is linearly normalized as the abnormal climbing parameter, which shows the difference between the steady-state temperature and the preset normal steady-state temperature; the ratio of the current heating rate to the preset normal heating rate is linearly normalized as the abnormal heating rate parameter, which shows the difference between the heating rate and the preset normal heating rate; the average of the abnormal climbing parameter and the abnormal heating rate parameter is taken as the current temperature anomaly degree.

[0095] It should be noted that, considering that the load of the double-contact circuit breaker is low when the current operating current is lower than the rated current, even if there is a slight poor contact or reduced heat dissipation, when the temperature anomaly is low, it means that the double-contact circuit breaker can still meet the circuit requirements, so the temperature anomaly is obtained based on this.

[0096] In another embodiment of the present invention, if the current current does not exceed the rated current, the steady-state temperature and the heating rate under the rated current are first obtained, and each is divided by the square of the rated current value, and the ratio is used as the preset normal steady-state temperature and the preset normal heating rate; the ratio of the current steady-state temperature to the square of the current current value and the difference between them and the preset normal steady-state temperature are linearly normalized and used as the abnormal climbing parameter; the ratio of the current heating rate to the square of the current current value and the ratio of them to the preset normal heating rate are linearly normalized and used as the abnormal heating rate parameter; and then the temperature anomaly degree is obtained to eliminate the influence of the current factor;

[0097] If the current current exceeds the rated current, the double-contact circuit breaker operates in overload. At this time, the temperature abnormality directly reflects the abnormal working state of the circuit breaker. Therefore, the difference between the current steady-state temperature and the preset normal steady-state temperature is linearly normalized as the abnormal climbing parameter, which shows the difference between the steady-state temperature and the preset normal steady-state temperature; the ratio of the current heating rate to the preset normal heating rate is linearly normalized as the abnormal heating rate parameter, which shows the difference between the heating rate and the preset normal heating rate; the average of the abnormal climbing parameter and the abnormal heating rate parameter is taken as the current temperature abnormality.

[0098] Step S5: Detect and display the state of the double-contact circuit breaker based on the current mechanical wear coefficient, peak performance abnormality, current fluctuation abnormality, and temperature abnormality.

[0099] After obtaining the mechanical wear coefficient from the perspective of mechanical wear, the peak performance abnormality and current fluctuation abnormality from the perspective of current waveform abnormality, and the temperature abnormality from the perspective of temperature abnormality, the current mechanical wear coefficient, peak performance abnormality, current fluctuation abnormality and temperature abnormality can be combined to comprehensively analyze and predict the gradual degradation of the double-contact circuit breaker, detect the status of the double-contact circuit breaker and display it, so as to timely identify potential abnormal fault problems of the double-contact circuit breaker, facilitate corresponding maintenance and repair, and ensure power safety.

[0100] Preferably, in one embodiment of the present invention, considering that the more severe the mechanical wear, the smaller the contact area of ​​the contacts, the insufficient spring pressure, and the more obvious the impact on electrical performance, greater attention is paid to the current waveform of the coil during opening and closing; when the mechanical wear is less, the double-contact circuit breaker itself has complete structural functions, and abnormal performance is more affected by environmental factors, so greater attention is paid to abnormal temperature performance;

[0101] Based on this, the first abnormality coefficient is obtained by integrating the current mechanical wear coefficient, peak performance abnormality and current fluctuation abnormality; the mechanical wear coefficient, peak performance abnormality and current fluctuation abnormality are all positively correlated with the first abnormality coefficient;

[0102] The second abnormal coefficient is obtained by fusing the current mechanical wear coefficient and temperature anomaly; the mechanical wear coefficient is negatively correlated with the second abnormal coefficient; the temperature anomaly is positively correlated with the second abnormal coefficient;

[0103] The first abnormality coefficient and the second abnormality coefficient are integrated to obtain the abnormal state coefficient of the current double-contact circuit breaker; whether the double-contact circuit breaker is in an abnormal state is determined according to the abnormal state coefficient, and the current state of the double-contact circuit breaker is displayed.

[0104] In one embodiment of the present invention, when the abnormal state coefficient is greater than a preset abnormal threshold, it is determined that the state of the double-contact circuit breaker is abnormal, and a fault light is turned on.

[0105] As an example, the preset abnormality threshold is 0.68; the average of the peak performance abnormality and the current fluctuation abnormality is multiplied by the mechanical wear coefficient, and the product is used as the first abnormality coefficient;

[0106] Multiply the difference between the constant 1 and the mechanical wear coefficient by the temperature anomaly, and use the product as the second anomaly coefficient;

[0107] The sum of the first abnormal coefficient and the second abnormal coefficient is used as the abnormal state coefficient.

[0108] The degree of abnormality of the current waveform is represented by the average of the peak performance abnormality and the current fluctuation abnormality. The greater the abnormality of the current waveform, the more abnormal the current performance, the more abnormal the operation of the double-contact circuit breaker, and the larger the abnormal state coefficient. The mechanical wear coefficient is used as a weight and multiplied by the average of the peak performance abnormality and the current fluctuation abnormality. The larger the mechanical wear coefficient, the more serious the mechanical wear, and the greater the attention paid to the current waveform.

[0109] The mechanical wear coefficient is negatively correlated by subtracting the constant 1 from the mechanical wear coefficient, and is used as a weight to weight the temperature anomaly. The greater the temperature anomaly, the more abnormal the temperature performance, and the larger the abnormal state coefficient. At the same time, the smaller the mechanical wear coefficient, the higher the attention to the temperature anomaly, and the greater the weight assigned.

[0110] In another embodiment of the present invention, considering that the greater the mechanical wear coefficient, the peak performance abnormality, the current fluctuation abnormality, and the temperature abnormality, the more abnormal the operation of the double-contact circuit breaker is from different perspectives, these four parameters can also be combined by multiplication or addition to obtain the state abnormality coefficient.

[0111] One embodiment of the present invention further provides a phase state detection and display device for a dual-contact circuit breaker, the device comprising a memory, a processor, and a computer program, wherein the memory is used to store the corresponding computer program, and the processor is used to run the corresponding computer program. When the computer program runs in the processor, it can implement a phase state detection and display method for a dual-contact circuit breaker described in steps S1-S5.

[0112] In summary, in response to the technical problem that existing detection methods cannot predict the gradual degradation fault of a double-contact circuit breaker, the present invention proposes a phase state detection and display method and device for a double-contact circuit breaker. The present invention first obtains the number of mechanical action data, temperature data and current waveform during opening and closing of the double-contact circuit breaker; further obtains the mechanical wear coefficient based on the total number of mechanical actions and the frequency of recent mechanical actions; further analyzes the current waveform during the latest opening and closing to obtain the current peak performance abnormality and current fluctuation abnormality; further analyzes the abnormal performance of the heating rate and steady-state temperature to obtain the current temperature abnormality; finally, combines the current mechanical wear coefficient, peak performance abnormality, current fluctuation abnormality and temperature abnormality to detect and display the state of the double-contact circuit breaker; comprehensively predicts the gradual degradation of the double-contact circuit breaker from multiple angles of mechanical wear, current waveform abnormality and temperature abnormality, and timely identifies the existence of potential abnormal fault problems in the double-contact circuit breaker.

[0113] It should be noted that the order in which the embodiments of the present invention are described above is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0114] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

Claims

1. A method for detecting and displaying the phase state of a double-contact circuit breaker, characterized in that: The method comprises: Obtain the number of mechanical action data, temperature data and current waveforms of the double-contact circuit breaker during opening and closing; Obtain the mechanical wear coefficient for the current day based on the total number of mechanical actions before the current day and the frequency of mechanical actions per day within a preset historical neighborhood of the current day; In the current waveform at the latest opening and closing time, the current peak performance abnormality is obtained based on the difference between the peak distribution and the preset normal peak distribution; the abnormal fluctuation period is screened out based on the dense distribution of extreme points; and the current current fluctuation abnormality is obtained based on the violent fluctuation of the current during the abnormal fluctuation period; In the temperature data, the current temperature abnormality is obtained based on the difference between the heating rate and the preset normal heating rate, combined with the difference between the steady-state temperature and the preset normal steady-state temperature; The state of the double-contact circuit breaker is detected and displayed in combination with the current mechanical wear coefficient, the peak performance abnormality, the current fluctuation abnormality, and the temperature abnormality.

2. The method for detecting and displaying the phase state of a double-contact circuit breaker according to claim 1, characterized in that: The method for obtaining the peak performance abnormality includes: Obtaining a trip peak abnormality coefficient based on a difference characteristic between a first large current peak value and a second large current peak value in the current waveform at the time of the latest trip; the difference characteristic between the first large current peak value and the second large current peak value is positively correlated with the trip peak abnormality coefficient; Obtaining a closing peak abnormality coefficient according to a difference between a ratio of a first maximum current peak value to a second maximum current peak value in the current waveform at the time of latest closing and a preset normal ratio; The opening peak abnormality coefficient and the closing peak abnormality coefficient are integrated to obtain the current peak performance abnormality.

3. The method for detecting and displaying the phase state of a double-contact circuit breaker according to claim 1, characterized in that: The method for obtaining the abnormal fluctuation period includes: In the current waveform at the latest trip, the time differences between adjacent extreme value points are obtained and time sequence numbers are obtained in a time sequence order; the time differences are arranged from small to large to form a time difference sorting sequence, the time difference sorting sequence is divided at the maximum element value of the first-order difference sequence of the time difference sorting sequence, and in a section of the time difference sorting sequence to which the smallest time difference belongs, the time period of the extreme value points corresponding to the time differences with consecutive time sequence numbers is used as the abnormal fluctuation period at the latest trip; Obtain the abnormal fluctuation period during the latest closing operation; the method for obtaining the abnormal fluctuation period during the latest closing operation is similar to the method for obtaining the abnormal fluctuation period during the latest opening operation.

4. The method for detecting and displaying the phase state of a double-contact circuit breaker according to claim 1, characterized in that: The method for obtaining the current fluctuation abnormality includes: Obtain the fluctuation intensity coefficient of the current value at the extreme point within each abnormal fluctuation period; combine the fluctuation intensity coefficient corresponding to the abnormal fluctuation period at the latest opening and the fluctuation intensity coefficient corresponding to the abnormal fluctuation period at the latest closing to obtain the current current fluctuation abnormality; the fluctuation intensity coefficient is positively correlated with the current fluctuation abnormality.

5. The method for detecting and displaying the phase state of a double-contact circuit breaker according to claim 1, characterized in that: The method for detecting and displaying the state of a double-contact circuit breaker includes: fusing the current mechanical wear coefficient, the peak performance abnormality, and the current fluctuation abnormality to obtain a first abnormality coefficient; the mechanical wear coefficient, the peak performance abnormality, and the current fluctuation abnormality are all positively correlated with the first abnormality coefficient; fusing the current mechanical wear coefficient and the temperature anomaly to obtain a second anomaly coefficient; the mechanical wear coefficient is negatively correlated with the second anomaly coefficient; and the temperature anomaly is positively correlated with the second anomaly coefficient; The first abnormality coefficient and the second abnormality coefficient are integrated to obtain the current abnormal state coefficient of the double-contact circuit breaker; whether the double-contact circuit breaker is in an abnormal state is determined according to the abnormal state coefficient, and the current state of the double-contact circuit breaker is displayed.

6. The method for detecting and displaying the phase state of a double-contact circuit breaker according to claim 5, characterized in that: When the abnormal state coefficient is greater than a preset abnormal threshold, it is determined that the state of the double-contact circuit breaker is abnormal, and a fault light is turned on.

7. The method for detecting and displaying the phase state of a double-contact circuit breaker according to claim 1, characterized in that: The method for obtaining the mechanical wear coefficient includes: The ratio of the total number of mechanical actions before the current day to the preset theoretical total number of mechanical actions is used as the first mechanical wear parameter of the current day; Obtaining a second mechanical wear parameter for the current day based on a proportional relationship between the number of mechanical actions per day within the preset historical neighborhood and the maximum number of mechanical actions per day in the historical days; The first mechanical wear parameter and the second mechanical wear parameter are integrated to obtain a mechanical wear coefficient for the current day; the first mechanical wear parameter and the second mechanical wear parameter are both positively correlated with the mechanical wear coefficient.

8. The method for detecting and displaying the phase state of a double-contact circuit breaker according to claim 4, characterized in that: The method for obtaining the fluctuation intensity coefficient includes: The standard deviation of the current value at the extreme point in each abnormal fluctuation period is linearly normalized and used as the corresponding fluctuation intensity coefficient.

9. The method for detecting and displaying the phase state of a double-contact circuit breaker according to claim 1, characterized in that: The preset historical neighborhood is the most recent 7 days.

10. A phase state detection and display device for a double-contact circuit breaker, the device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method for detecting and displaying the phase state of a double-contact circuit breaker according to any one of claims 1 to 9 are implemented.

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