A method and apparatus for detecting and displaying the phase status of a double contact circuit breaker

Abstract

The present application relates to the technical field of circuit breaker detection, and particularly relates to a phase state detection and display method and device for a double-contact circuit breaker. The present application first acquires the number of mechanical actions, temperature data and current waveform at the time of opening and closing; further acquires the mechanical wear coefficient according to the total number of mechanical actions and the frequency of recent mechanical actions; further analyzes the current waveform at the time of the latest opening and closing to acquire the current abnormality degree of wave crest performance and current fluctuation; further analyzes the abnormal performance of the temperature rise rate and the steady-state temperature to acquire the current temperature abnormality degree; finally, the current mechanical wear coefficient, wave crest performance abnormality degree, current fluctuation abnormality degree and temperature abnormality degree are combined to detect the state of the double-contact circuit breaker and display the state; the gradual degradation of the double-contact circuit breaker is comprehensively predicted from the aspects of mechanical wear, abnormal performance of current waveform and abnormal performance of temperature, so that potential abnormal fault problems of the double-contact circuit breaker can be identified in time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit breaker detection, in particular to a phase state detection and display method and device for a double-contact circuit breaker. BACKGROUND

[0002] In the phase detection process of a double-contact circuit breaker, the existing monitoring method can only feedback abnormal states when the circuit breaker contacts have serious faults, mainly including contact welding, complete disconnection or current over-limit, etc. These faults generally have obvious instantaneous characteristics, so the monitoring system can respond in time. However, there is a lack of predictive ability for potential faults, especially in detecting the gradual degradation process of contact wear, oxidation, contamination, etc.

[0003] At the same time, this limitation is particularly prominent in complex working conditions or high reliability requirement scenarios. For example, in high-load, high-safety requirement application scenarios such as power systems and industrial automation, failure to effectively identify gradual degradation faults in advance may lead to serious equipment downtime, production interruption, and even safety accidents. This not only hinders the long-term stability of the equipment, but also may cause the overall system to run less efficiently and lose economic benefits. SUMMARY

[0004] In order to solve the technical problem that the existing detection method cannot predict the gradual degradation faults of a double-contact circuit breaker, the purpose of the present application is to provide a phase state detection and display method and device for a double-contact circuit breaker, and the technical solution adopted is as follows:

[0005] A phase state detection and display method for a double-contact circuit breaker, the method comprising:

[0006] Obtaining the number of times of mechanical actions, temperature data and current waveform at the time of opening and closing of the double-contact circuit breaker;

[0007] According to the total number of mechanical actions before the current day, in combination with the frequency of mechanical actions each day within the preset historical neighborhood of the current day, obtaining the mechanical wear coefficient of the current day;

[0008] In the current waveform at the latest opening and closing, according to the difference between the peak distribution and the preset normal peak distribution, obtaining the current peak abnormality degree; according to the intensive distribution of extreme points, screening out an abnormal fluctuation period; according to the violent fluctuation of current in the abnormal fluctuation period, obtaining the current current fluctuation abnormality degree;

[0009] In the temperature data, according to the difference between the temperature rise rate and the preset normal temperature rise rate, in combination with the difference between the steady-state temperature and the preset normal steady-state temperature, obtaining the current temperature abnormality degree;

[0010] The mechanical wear coefficient, the abnormality degree of the wave crest, the abnormality degree of the current fluctuation and the abnormality degree of the temperature are combined to detect the state of the double-contact circuit breaker and display the state.

[0011] Further, the method for obtaining the abnormality degree of the wave crest comprises:

[0012] According to the difference feature of the first large current wave crest value and the second large current wave crest value in the current waveform at the latest opening, an opening wave crest abnormality coefficient is obtained; the difference feature of the first large current wave crest value and the second large current wave crest value is positively correlated with the opening wave crest abnormality coefficient.

[0013] According to the difference between the ratio of the first large current wave crest value and the second large current wave crest value in the current waveform at the latest closing and a preset normal ratio, a closing wave crest abnormality coefficient is obtained.

[0014] The opening wave crest abnormality coefficient and the closing wave crest abnormality coefficient are fused to obtain the current abnormality degree of the wave crest.

[0015] Further, the method for obtaining the abnormal fluctuation period comprises:

[0016] In the current waveform at the latest opening, the time difference between adjacent extreme points is obtained and the time sequence number is obtained in time sequence order; the time difference is 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 a first-order difference sequence of the time difference sorting sequence, and the time period of the extreme points corresponding to the time difference with continuous time sequence numbers in the time difference sorting sequence to which the minimum time difference belongs is taken as the abnormal fluctuation period at the latest opening.

[0017] The abnormal fluctuation period at the latest closing is obtained; the method for obtaining the abnormal fluctuation period at the latest closing is similar to the method for obtaining the abnormal fluctuation period at the latest opening.

[0018] Further, the method for obtaining the abnormality degree of the current fluctuation comprises:

[0019] The fluctuation intensity coefficient of the current value of the extreme point in each abnormal fluctuation period is obtained; the fluctuation intensity coefficients corresponding to the abnormal fluctuation periods at the latest opening and the abnormal fluctuation periods at the latest closing are fused to obtain the current abnormality degree of the current fluctuation; the fluctuation intensity coefficient is positively correlated with the current fluctuation abnormality degree.

[0020] Further, the method for detecting the state of the double-contact circuit breaker and displaying the state comprises:

[0021] Fuse the current mechanical wear coefficient, the wave crest abnormality degree and the current fluctuation abnormality degree to obtain a first abnormality coefficient; the mechanical wear coefficient, the wave crest abnormality degree and the current fluctuation abnormality degree are positively correlated with the first abnormality coefficient;

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

[0023] Fuse the first abnormality coefficient and the second abnormality coefficient to obtain a current abnormality state coefficient of the double-contact circuit breaker; determine whether the double-contact circuit breaker is abnormal according to the abnormality state coefficient, and display the current state of the double-contact circuit breaker.

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

[0025] Further, the method for obtaining the mechanical wear coefficient comprises:

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

[0027] According to the proportional relationship between the number of mechanical actions in each day in the preset historical neighborhood and the maximum number of mechanical actions in a single day in the historical days, a second mechanical wear parameter of the current day is obtained;

[0028] Fuse the first mechanical wear parameter and the second mechanical wear parameter to obtain a mechanical wear coefficient of the current day; the first mechanical wear parameter and the second mechanical wear parameter are positively correlated with the mechanical wear coefficient.

[0029] Further, the method for obtaining the fluctuation severity coefficient comprises:

[0030] The standard deviation of the current value of the extreme point in each abnormal fluctuation period is linearly normalized to obtain the corresponding fluctuation severity coefficient.

[0031] Further, the preset historical neighborhood is the last 7 days.

[0032] The application further provides a phase state detection and display device for a double-contact circuit breaker, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of any one of the phase state detection and display methods for a double-contact circuit breaker.

[0033] The application has the following beneficial effects:

[0034] The application firstly acquires the number of times data, temperature data and current waveform at the time of opening and closing of the mechanical action of the double contact circuit breaker, provides a data basis for subsequent detection of the gradual degradation of the double contact circuit breaker; further acquires the current mechanical wear coefficient, representing the mechanical wear intensity of the double contact circuit breaker, to predict the gradual degradation of mechanical wear, and provide a basis for subsequent evaluation of the working state of the double contact circuit breaker; further, in the current waveform at the latest opening and closing, the abnormal performance characteristics of the current are evaluated from the perspective of abnormal peak distribution, and the current peak performance abnormality degree is acquired; further, according to the abnormal fluctuation of the current in the abnormal fluctuation period of the extreme point intensive distribution, the current fluctuation abnormality degree is acquired, and the abnormal performance characteristics of the current are evaluated from the perspective of current abnormal fluctuation, to provide a basis for subsequent evaluation of the working state of the double contact circuit breaker; further, according to the difference between the temperature rise rate and the preset normal temperature rise rate, combined with the difference between the steady-state temperature and the preset normal steady-state temperature, the current temperature abnormality degree is acquired, and the thermal state abnormality of the circuit breaker is comprehensively evaluated from two dimensions of dynamic and static, to find out the gradual degradation faults such as contact oxidation, looseness or deterioration of the heat dissipation system in advance, and provide more basis for subsequent evaluation of the working state of the double contact circuit breaker; finally, the current mechanical wear coefficient, the peak performance abnormality degree, the current fluctuation abnormality degree and the temperature abnormality degree are combined to detect and display the state of the double contact circuit breaker. The gradual degradation of the double contact circuit breaker is comprehensively predicted from the perspectives of mechanical wear, abnormal performance of current waveform and abnormal performance of temperature, and the potential abnormal fault problems of the double contact circuit breaker are identified in time. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, and the advantages thereof, a brief introduction will be given to the drawings needed in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor based on these drawings.

[0036] Figure 1 A flow chart of a phase state detection and display method of a double contact circuit breaker provided by an embodiment of the present application;

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

[0038] Figure 3 A current waveform diagram of an opening and closing coil of a double contact circuit breaker in a normal condition provided by an embodiment of the present application;

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

[0040] The reference signs in the drawing are: 1, handle; 2, connecting rod; 3, shell; 4, trip coil; 5, terminal screw; 6, arc extinguishing chamber; 7, magnetic blowout coil. DETAILED DESCRIPTION

[0041] In order to further clarify the technical means and effects taken by the present application to achieve the predetermined object of the application, the following describes in detail the specific implementation, structure, features and effects of a phase state detection and display method and device for a double-contact circuit breaker according to the present application, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

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

[0043] The specific scheme of the phase state detection and display method and device for a double-contact circuit breaker provided by the present application is described in detail below in combination with the accompanying drawings.

[0044] Please refer to Figure 1 which shows a flowchart of a phase state detection and display method for a double-contact circuit breaker according to one embodiment of the present application, which specifically includes:

[0045] Step S1: Obtain the number of mechanical actions, temperature data and current waveform at the time of 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 that the temperature during normal operation and the current waveform at the time of opening and closing have certain normal patterns, obtaining the number of mechanical actions, temperature data and current waveform at the time of opening and closing of the double-contact circuit breaker provides a data basis for subsequent detection of the gradual degradation of the double-contact circuit breaker.

[0047] In one embodiment of the present application, the number of mechanical actions is obtained through the microswitch of the double-contact circuit breaker; the current data is obtained through the high-precision current sensor (sampling rate ≥ 10 kHz) of the double-contact circuit breaker, and the current data at the time of opening and closing is intercepted to obtain the current waveform of the opening and closing coil; 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 the high-voltage circuit breaker changing with time when the high-voltage circuit breaker performs the opening (circuit breaking) or closing (circuit closing) operation. This waveform can be captured by a high-sampling-rate sensor to reflect the real-time state of the mechanical operating mechanism, electromagnetic system and control circuit of the circuit breaker.

[0049] Referring to Figure 2 , which shows a structural schematic diagram of a double contact circuit breaker provided by an embodiment of the application; in the diagram, reference numerals are as follows: 1, handle; 2, connecting rod; 3, shell; 4, trip coil; 5, terminal screw; 6, arc chamber; 7, magnetic blowout coil; 1, handle is used for manually controlling the circuit breaker, and the operating force is transmitted through 2, connecting rod to control the contact; 3, shell is used for fixing the internal components; 4, trip coil is the core of the protection device of the circuit breaker, and when an overload or short circuit occurs in the circuit, the coil is energized to generate an electromagnetic force, which drives the trip mechanism to act to force the contact to separate to cut off the circuit; 5, terminal screw is used for fixing the external load line and power line; 6, arc chamber is a key component for extinguishing the arc generated when the contact is broken; and 7, magnetic blowout coil generates a magnetic field to assist the arc into 6, arc chamber and eliminate the arc energy.

[0050] The double contact circuit breaker is generally composed of a main contact and an arc contact, and the design allows the current to pass through two independent contact systems, so that the double contact circuit breaker can achieve higher on-off capacity in high current conditions.

[0051] The main contact is used to bear the normal working current conduction, has low contact resistance, and is mostly made of silver-based alloy; and the arc contact is used to bear the arc ablation when breaking the fault current and is made of high-temperature-resistant material (such as copper-tungsten alloy).

[0052] When power is on: the current forms a loop through the main contact and the arc contact, and the arc is generated when the current passes through the arc contact, 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 trip mechanism will act quickly to separate the moving contact from the static contact to cut off the circuit.

[0054] Step S2: According to the total number of mechanical actions before the current day, and in combination with the frequency of mechanical action of each day in the preset historical neighborhood of the current day, the mechanical wear coefficient of the current day is obtained.

[0055] With the accumulation of the number of mechanical actions, spring fatigue, oxidation and damage of the contact surface, and the like will occur, resulting in loss of performance and deformation of the material, and the performance presents a gradual degradation trend, so the total number of mechanical actions before the current day reflects the mechanical wear characteristics; in addition, the frequency of mechanical action in the recent period reflects the frequent start-stop of the load and the frequent situation of overload or short circuit events, and also reflects the mechanical wear characteristics of the circuit breaker, so the frequency of mechanical action of each day in the preset historical neighborhood of the current day is also combined to obtain the mechanical wear coefficient of the current day, which represents the mechanical wear strength of the double contact circuit breaker, so as to predict the gradual degradation of the mechanical wear and provide a basis for subsequent evaluation of the working state of the double contact circuit breaker.

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

[0057] Considering that the greater the number of mechanical actions on a certain day compared to the maximum number of mechanical actions per day, the more frequent the mechanical actions on that day, the more serious the mechanical wear, so according to the proportional relationship 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 days, the second mechanical wear parameter of the current day is obtained.

[0058] The first mechanical wear parameter and the second mechanical wear parameter are fused to obtain the mechanical wear coefficient of the current day; 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 last 7 days before the current day; the preset total number of theoretical mechanical actions of the double-contact circuit breaker is obtained through the product manual or laboratory data;

[0060] For each day of the 7 days before the current day, the ratio of the number of mechanical actions per day to the maximum number of mechanical actions per day is taken as the second wear sub-parameter, and the second wear sub-parameters of the 7 days are accumulated and linearly normalized to obtain the second mechanical wear parameter; the product of the first mechanical wear parameter and the second mechanical wear parameter is taken as the mechanical wear coefficient of the current day.

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

[0062] In another embodiment of the present application, considering that the more mechanical actions per day, the greater the second wear sub-parameter, the more frequent the mechanical actions on that day, so the product of the second wear sub-parameter and the number of mechanical actions per day for each of the 7 days before the current day can also be taken as the mechanical action frequency of each day; the mechanical action frequencies of the 7 days are accumulated and linearly normalized to obtain the second mechanical wear parameter.

[0063] In other embodiments of the present application, the implementer can 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 current waveform of the latest on-off, the current peak abnormality degree is obtained according to the difference between the peak distribution and the preset normal peak distribution; the abnormal fluctuation period is selected according to the dense distribution of the extreme points; and the current fluctuation abnormality degree is obtained according to the severe fluctuation of the current in the abnormal fluctuation period.

[0065] For the current waveform performance of the on-off coil of the double-contact circuit breaker, by analyzing and capturing the transient characteristics of the current, abnormal fault conditions such as operation mechanism jamming (waveform distortion), electromagnetic remanence (current tailing) or coil turn-to-turn short circuit (amplitude abnormality) can be identified, and the gradual degradation of the double-contact circuit breaker can be analyzed from the perspective of the current waveform performance.

[0066] Please participate Figure 3 which shows a current waveform diagram of the on-off coil of the double-contact circuit breaker under normal conditions according to an embodiment of the present application; Figure 3 In the current waveform diagram, the horizontal axis is the time axis, the vertical axis is the current value axis, the left side corresponds to the coil current waveform during on, and the time length is 40 ms; the right side corresponds to the coil current waveform during off, and the time length is 80 ms; during the analysis of the current waveform of the double-contact circuit breaker, the on current waveform is intercepted for 40 ms after on, and the off current waveform is intercepted for 80 ms after off.

[0067] The peak distribution of the current waveform of the double-contact circuit breaker under normal conditions has a relatively fixed distribution mode, so in the current waveform of the latest on-off, the current peak abnormality degree is obtained according to 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 abnormal peak distribution, and a basis is provided for subsequent evaluation of the working state of the double-contact circuit breaker.

[0068] Preferably, in an embodiment of the present application, the maximum point of the current value is taken as a peak, and the peaks are sorted according to the size of the maximum points; Figure 3 In the current waveform diagram, the first and second largest current peak values during on are kept in a similar state, the first largest current peak value during off is larger than the second largest current peak value, and the second largest current peak value is generally about half of the first largest current peak value, so the preset normal peak distribution includes that the first and second largest current peak values during on are similar, and the preset normal ratio of the first and second largest current peak values during off;

[0069] Since the corresponding preset normal peak distribution at the time of opening is that the first and second maximum current peak values are similar, the arc extinguishing efficiency and the complete coordination of the contact action have no difference; since the difference between the two data and the ideal difference 0 is equivalent to the difference between the two data themselves, for example, |A-0|=|A|, A represents the difference between the first and second maximum current peak values, the difference between the first and second maximum current peak values in the current waveform at the time of the latest opening reflects the difference between the peak distribution at the time of opening and the preset normal peak distribution;

[0070] Therefore, according to the difference feature of the first and second maximum current peak values in the current waveform at the time of the latest opening, an opening peak abnormality coefficient is obtained; the difference feature of the first and second maximum current peak values is positively correlated with the opening peak abnormality coefficient;

[0071] According to the difference between the ratio of the first and second maximum current peak values in the current waveform at the time of the latest closing and the preset normal ratio, a closing peak abnormality coefficient is obtained;

[0072] The opening peak abnormality coefficient and the closing peak abnormality coefficient are fused to obtain a current peak performance abnormality degree.

[0073] As an example, the absolute value of the difference between the first and second maximum current peak values (current values) is linearly normalized to serve as the opening peak abnormality coefficient; the difference feature of the first and second maximum current peak values is represented in the form of the absolute value of the difference.

[0074] The ratio of the first and second maximum current peak values at the time of closing under normal conditions is taken as the preset normal ratio; the absolute value of the difference between the ratio of the first and second maximum current peak values in the current waveform at the time of the latest closing and the preset normal ratio is linearly normalized, and the normalized result is taken as the closing peak abnormality coefficient; the difference between the ratio of the first and second maximum current peak values in the current waveform at the time of the latest closing and the preset normal ratio is represented in the form of the absolute value of the difference, wherein the first maximum current peak value is in the numerator position when the ratio is calculated.

[0075] Finally, the average of the opening peak abnormality coefficient and the closing peak abnormality coefficient is taken as the current peak performance abnormality degree, which represents the abnormality degree of the opening and closing coil current performance of the current double-contact circuit breaker.

[0076] Please refer to Figure 4 which shows an abnormal current waveform diagram provided by one embodiment of the present application; Figure 4The abnormal current fluctuation in different stages (which can be roughly regarded as three stages of front, middle and rear) during opening and closing is shown in the figure, which corresponds to the jamming of the core, defects of the locking mechanism and other fault performances.

[0077] From Figure 4 As can be seen from the figure, when the abnormal current fluctuation of the double-contact circuit breaker occurs, there are densely distributed current extreme points, and the current in these abnormal periods presents a sharp fluctuation, so according to the dense distribution of the extreme points, the abnormal fluctuation period is screened out; according to the sharp fluctuation of the current in the abnormal fluctuation period, the current fluctuation abnormality degree is obtained, the abnormal performance characteristics of the current are evaluated from the angle of current abnormal fluctuation, and a basis is provided for subsequent evaluation of the working state of the double-contact circuit breaker.

[0078] Preferably, in an embodiment of the present application, considering that the more dense the extreme points are, the smaller the time difference between adjacent extreme points is, so in the current waveform during the latest opening, the time difference between adjacent extreme points is obtained and the time sequence number is obtained in time sequence order; the time difference is arranged from small to large to form a time difference sorting sequence, and the dense distribution of the extreme points is analyzed by means of the time difference sorting sequence;

[0079] Considering that the first-order difference of the time difference sorting sequence is calculated, the maximum value thereof corresponds to the significant jump point of the time difference distribution, which reflects the turning point of the extreme point density from sparse to dense, so 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 the time period of the extreme points corresponding to the time difference with continuous time sequence number in the time difference sorting sequence with the smallest time difference is taken as the abnormal fluctuation period during the latest opening;

[0080] The abnormal fluctuation period during the latest closing is obtained; the method for obtaining the abnormal fluctuation period during the latest closing is similar to that for obtaining the abnormal fluctuation period during the latest opening.

[0081] Specifically, in the current waveform during the latest closing, the time difference between adjacent extreme points is obtained and the time sequence number is obtained in 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, and the time period of the extreme points corresponding to the time difference with continuous time sequence number in the time difference sorting sequence with the smallest time difference is taken as the abnormal fluctuation period during the latest closing.

[0082] For example, there are 13 extreme points, and 12 time differences are obtained, with the sequence numbers being [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]; after sorting and dividing the time difference sequence, [1, 3, 4, 5, 6, 10, 12], [2, 7, 8, 9, 11] are obtained; the smallest time difference is 5, so in the selected sequence [1, 3, 4, 5, 6, 10, 12], the time differences with the time sequence numbers [3, 4, 5, 6] are continuous, the extreme points with the time sequence numbers [3, 4, 5, 6, 7] are continuous, and the time period between the extreme points with the time sequence numbers 3 to 7 is taken as the abnormal fluctuation period.

[0083] In other embodiments of the present application, a time difference threshold can be set, and the time difference sequence is divided at the first time difference greater than or equal to the time difference threshold.

[0084] Preferably, in an embodiment of the present application, considering that the extreme points are points of significant change of current in the abnormal fluctuation period, the fluctuation intensity coefficient of the current value of the extreme points in each abnormal fluctuation period is obtained by analyzing the fluctuation intensity characteristics of the current at the extreme points, to represent the violent fluctuation of the current in the abnormal fluctuation period.

[0085] Therefore, the fluctuation intensity coefficient of the current value of the extreme points in each abnormal fluctuation period is obtained, the fluctuation intensity coefficient corresponding to the abnormal fluctuation period at the latest opening is fused, and the fluctuation intensity coefficient corresponding to the abnormal fluctuation period at the latest closing is fused to obtain the current fluctuation abnormality degree; the fluctuation intensity coefficient is positively correlated with the current fluctuation abnormality degree.

[0086] As an example: the standard deviation of the current value of the extreme points in each abnormal fluctuation period is linearly normalized to serve as the corresponding fluctuation intensity coefficient; the mean of the fluctuation intensity coefficient at the latest opening and the fluctuation intensity coefficient at the latest closing is taken as the current fluctuation abnormality degree.

[0087] It should be noted that when there are multiple abnormal fluctuation periods at the latest opening or closing, for example, there are 3 abnormal fluctuation periods at the opening, the fluctuation intensity coefficients of the 3 abnormal fluctuation periods are obtained respectively, and finally the mean of the 3 fluctuation intensity coefficients is taken as the fluctuation intensity coefficient at the latest opening.

[0088] In other embodiments of the present application, the fluctuation intensity coefficient of all current values in each abnormal fluctuation period can also be obtained to obtain the current fluctuation abnormality degree; one or more of the parameters for measuring the fluctuation intensity of the data, such as the variance, standard deviation, range, and mean absolute deviation of the current value, can also be fused by addition or multiplication to obtain the fluctuation intensity coefficient, which is a technical means known to those skilled in the art and will not be described in detail.

[0089] Step S4: In the temperature data, according to the difference between the temperature rising rate and the preset normal temperature rising rate, and the difference between the steady temperature and the preset normal steady temperature, the current temperature abnormality degree is obtained.

[0090] Considering that in the double-contact circuit breaker, the temperature abnormality is usually closely related to the contact resistance change, overload, poor heat dissipation or contact aging; when the contact is gradually oxidized, worn, causes poor contact, or the dust accumulation in the heat dissipation system, fan failure or high environmental temperature causes insufficient heat dissipation performance, or overload operation, the temperature rising rate and the steady temperature gradually deviate from the normal value, therefore, in the temperature data, according to the difference between the temperature rising rate and the preset normal temperature rising rate, and the difference between the steady temperature and the preset normal steady temperature, the current temperature abnormality degree is obtained.

[0091] By analyzing the difference between the temperature rising rate and the steady temperature and the preset normal value, the thermal state abnormality of the circuit breaker can be comprehensively evaluated from two dimensions of dynamic and static, so as to find the gradual degradation faults such as contact oxidation, loosening or heat dissipation system degradation in advance, and provide more basis for subsequent evaluation of the working state of the double-contact circuit breaker.

[0092] Preferably, in an embodiment of the present application, first, the temperature rising curve of the contact is obtained under the rated current, the initial temperature before temperature rising and the steady temperature after temperature rising (when heat balance) are obtained, and according to the temperature rising time, the ratio of the difference between the steady temperature and the initial temperature to the temperature rising time is taken as the temperature rising rate, the preset normal temperature rising rate and the preset normal steady temperature are obtained;

[0093] The steady temperature and the temperature rising rate of the contact are obtained in the same way;

[0094] Considering that the higher the current steady temperature is compared with the normal value, the higher the temperature rising rate is compared with the normal value, the more abnormal the contact works, therefore, the difference between the current steady temperature and the preset normal steady temperature is linearly normalized as an abnormal rising parameter, which represents the difference between the steady temperature and the preset normal steady temperature; the ratio of the current temperature rising rate to the preset normal temperature rising rate is linearly normalized as an abnormal temperature rising rate parameter, which represents the difference between the temperature rising rate and the preset normal temperature rising rate; the average of the abnormal rising parameter and the abnormal temperature rising rate parameter is taken as the current temperature abnormality degree.

[0095] It should be noted that considering that the current working current is lower than the rated current, the load of the double-contact circuit breaker is low, even if there is slight contact failure or heat dissipation decline, when the temperature abnormality degree is low, it means that the double-contact circuit breaker can meet the circuit demand, therefore, the temperature abnormality degree is obtained in this way.

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

[0097] If the current exceeds the rated current, the double-contact circuit breaker will operate under overload. At this time, the abnormal temperature directly reflects the abnormal operating state of the circuit breaker. Therefore, the difference between the current steady-state temperature and the preset normal steady-state temperature is linearly normalized and used as the abnormal rise parameter to show 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 and used as the abnormal heating rate parameter to show the difference between the heating rate and the preset normal heating rate. The average of the abnormal rise parameter and the abnormal heating rate parameter is used as the current temperature anomaly degree.

[0098] Step S5: Combine the current mechanical wear coefficient, peak performance anomaly, current fluctuation anomaly, and temperature anomaly to detect and display the status of the double-contact circuit breaker.

[0099] After obtaining the mechanical wear coefficient from the perspective of mechanical wear, the abnormality degree of peak performance and the abnormality degree of current fluctuation from the perspective of current waveform abnormality, and the abnormality degree of temperature performance from the perspective of temperature abnormality, the gradual degradation of the double-contact circuit breaker can be comprehensively analyzed and predicted by combining the current mechanical wear coefficient, abnormality degree of peak performance, abnormality degree of current fluctuation, and abnormality degree of temperature. The status of the double-contact circuit breaker can be detected and displayed, so as to identify potential abnormal faults in the double-contact circuit breaker in a timely manner, which facilitates corresponding maintenance and repair, and ensures electrical 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 and the less the spring pressure, 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 smaller, 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 anomaly coefficient is obtained by integrating the current mechanical wear coefficient, peak performance anomaly degree, and current fluctuation anomaly degree; the mechanical wear coefficient, peak performance anomaly degree, and current fluctuation anomaly degree are all positively correlated with the first anomaly coefficient;

[0102] Fuse the current mechanical wear coefficient and the temperature abnormality degree to obtain a second abnormality coefficient; the mechanical wear coefficient is negatively correlated with the second abnormality coefficient; the temperature abnormality degree is positively correlated with the second abnormality coefficient;

[0103] Fuse the first abnormality coefficient and the second abnormality coefficient to obtain an abnormality state coefficient of the current double-contact circuit breaker; determine whether the double-contact circuit breaker is abnormal according to the abnormality state coefficient, and display the current state of the double-contact circuit breaker.

[0104] In an embodiment of the present application, when the abnormality state coefficient is greater than a preset abnormality threshold, it is determined that 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 mean value of the wave peak abnormality degree and the current fluctuation abnormality degree is multiplied by the mechanical wear coefficient, and the product is taken as the first abnormality coefficient;

[0106] The difference between the constant 1 and the mechanical wear coefficient is multiplied by the temperature abnormality degree, and the product is taken as the second abnormality coefficient;

[0107] The sum of the first abnormality coefficient and the second abnormality coefficient is taken as the abnormality state coefficient.

[0108] Among them, the mean value of the wave peak abnormality degree and the current fluctuation abnormality degree represents the abnormality degree of the current waveform, the greater the current waveform abnormality degree, the more abnormal the current performance, the more abnormal the double-contact circuit breaker works, and the greater the abnormality state coefficient; the mechanical wear coefficient is multiplied as a weight with the mean value of the wave peak abnormality degree and the current fluctuation abnormality degree, the greater the mechanical wear coefficient, the more serious the mechanical wear, and the greater the attention to the current waveform;

[0109] The mechanical wear coefficient is negatively correlated by subtracting the mechanical wear coefficient from the constant 1, so as to be weighted to the temperature abnormality degree; the greater the temperature abnormality degree, the more abnormal the temperature performance, and the greater the abnormality state coefficient; at the same time, the smaller the mechanical wear coefficient, the higher the attention to the temperature abnormality, and the greater the weight.

[0110] In another embodiment of the present application, considering that the greater the mechanical wear coefficient, the wave peak abnormality degree, the current fluctuation abnormality degree and the temperature abnormality degree, the more abnormal the double-contact circuit breaker works from different angles, so the four parameters can also be fused by multiplication or addition to obtain the state abnormality coefficient.

[0111] The embodiment of the present application also provides a phase state detection display device of a double-contact circuit breaker, which comprises a memory, a processor and a computer program, wherein the memory is used for storing the corresponding computer program, the processor is used for running the corresponding computer program, and the computer program can realize the double-contact circuit breaker phase state detection display method described in steps S1-S5 when running in the processor.

[0112] To sum up, in order to solve the technical problem that the existing detection method cannot predict the gradual degradation failure of the double-contact circuit breaker, the present application provides a double-contact circuit breaker phase state detection display method and device. Firstly, the present application obtains the number data of mechanical actions, temperature data and current waveform at the on-off of the double-contact circuit breaker; further, the mechanical wear coefficient is obtained according to the total number of mechanical actions and the frequency of recent mechanical actions; further, the current waveform at the latest on-off is analyzed to obtain the current abnormality degree of wave peak performance and current fluctuation; further, the abnormal performance of the temperature rise rate and the steady-state temperature is analyzed to obtain the current temperature abnormality degree; finally, the current mechanical wear coefficient, wave peak performance abnormality degree, current fluctuation abnormality degree and temperature abnormality degree are combined to detect and display the state of the double-contact circuit breaker; the gradual degradation of the double-contact circuit breaker is predicted from the aspects of mechanical wear, current waveform abnormal performance and temperature abnormal performance, so that the potential abnormal failure problem of the double-contact circuit breaker can be identified in time.

[0113] It should be noted that the above-mentioned embodiment sequence of the present application is only for description, and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or may be advantageous.

[0114] Each embodiment in the specification is described in a progressive manner, and the same and similar parts between each embodiment can be referred to each other, and each embodiment mainly describes the difference from other embodiments.

Claims

1. A method for detecting and displaying the phase status of a two-contact circuit breaker, characterized in that, The method includes: Acquire data on the number of mechanical actions, temperature, and current waveforms during opening and closing of the double-contact circuit breaker; Based on the total number of mechanical actions before the current day, and combined with the frequency of mechanical actions in the preset historical neighborhood for the current day, the mechanical wear coefficient for the current day is obtained. In the latest current waveform during opening and closing, 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 fluctuation abnormality is obtained based on the violent fluctuation of the current during the abnormal fluctuation period. In the temperature data, the current temperature anomaly is obtained by combining the difference between the heating rate and the preset normal heating rate with the difference between the steady-state temperature and the preset normal steady-state temperature. Based on the current mechanical wear coefficient, peak performance anomaly, current fluctuation anomaly, and temperature anomaly, the status of the double-contact circuit breaker is detected and displayed; The method for obtaining the peak performance anomaly degree includes: obtaining the peak anomaly coefficient of the tripping circuit based on the difference between the peak value of the first and second largest current waves in the current waveform at the latest tripping time; the difference between the peak value of the first and second largest current waves is positively correlated with the peak anomaly coefficient of the tripping circuit; obtaining the peak anomaly coefficient of the closing circuit based on the difference between the ratio of the peak value of the first and second largest current waves in the current waveform at the latest closing time and the preset normal ratio; and fusing the peak anomaly coefficient of the tripping circuit and the peak anomaly coefficient of the closing circuit to obtain the current peak performance anomaly degree.

2. The phase state detection and display method for a dual-contact circuit breaker according to claim 1, characterized in that, Methods for obtaining periods of abnormal fluctuations include: In the current waveform at the latest circuit breaker trip, the time difference between adjacent extreme points is obtained and the time sequence number is obtained in the 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; in the time difference sorting sequence to which the smallest time difference belongs, the time period of the extreme point corresponding to the consecutive time difference of the time sequence number is taken as the abnormal fluctuation period at the latest circuit breaker trip. Obtain the period of abnormal fluctuations at the latest closing time; the method for obtaining the period of abnormal fluctuations at the latest closing time is similar to that at the latest opening time.

3. The phase state detection and display method for a dual-contact circuit breaker according to claim 1, characterized in that, Methods for obtaining the anomaly degree of current fluctuation include: Obtain the fluctuation severity coefficient of the current value at the extreme point within each abnormal fluctuation period; combine the fluctuation severity coefficients corresponding to the abnormal fluctuation period at the latest opening and the abnormal fluctuation period at the latest closing to obtain the current fluctuation anomaly degree; the fluctuation severity coefficient is positively correlated with the current fluctuation anomaly degree.

4. The phase state detection and display method for a dual-contact circuit breaker according to claim 1, characterized in that, Methods for detecting and displaying the status of a two-contact circuit breaker include: The first anomaly coefficient is obtained by combining the current mechanical wear coefficient, peak performance anomaly degree, and current fluctuation anomaly degree; the mechanical wear coefficient, peak performance anomaly degree, and current fluctuation anomaly degree are all positively correlated with the first anomaly coefficient; The second anomaly coefficient is obtained by combining the current mechanical wear coefficient and temperature anomaly degree; the mechanical wear coefficient is negatively correlated with the second anomaly coefficient; the temperature anomaly coefficient is positively correlated with the second anomaly coefficient. The abnormal state coefficient of the current double-contact circuit breaker is obtained by combining the first abnormal coefficient and the second abnormal coefficient; the abnormal state coefficient is used to determine whether the double-contact circuit breaker is in an abnormal state, and the current state of the double-contact circuit breaker is displayed.

5. The phase state detection and display method for a dual-contact circuit breaker according to claim 4, characterized in that, When the abnormal state coefficient is greater than the preset abnormal threshold, the double contact circuit breaker is determined to be in an abnormal state and the fault light is illuminated.

6. The phase state detection and display method for a dual-contact circuit breaker according to claim 1, characterized in that, Methods for obtaining the mechanical wear coefficient include: The ratio of the total number of mechanical actions performed 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. Based on the ratio of the number of mechanical actions per day within the preset historical neighborhood to the maximum number of mechanical actions per day in the historical days, the second mechanical wear parameter for the current day is obtained. The mechanical wear coefficient for the current day is obtained by integrating the first mechanical wear parameter and the second mechanical wear parameter; both the first mechanical wear parameter and the second mechanical wear parameter are positively correlated with the mechanical wear coefficient.

7. The phase state detection and display method for a dual-contact circuit breaker according to claim 3, characterized in that, Methods for obtaining the volatility coefficient include: The standard deviation of the current value at the extreme point within each abnormal fluctuation period is linearly normalized and used as the corresponding fluctuation severity coefficient.

8. The phase state detection and display method for a dual-contact circuit breaker according to claim 1, characterized in that, The default historical neighborhood is the most recent 7 days.

9. A phase status detection and display device for a two-contact circuit breaker, the device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the phase state detection and display method for a dual-contact circuit breaker as described in any one of claims 1 to 8.

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