Circuit breaker life monitoring method and device

Abstract

A method for monitoring the life of a circuit breaker includes obtaining and storing an original life decay curve as a basic life decay curve for the next update of the life decay curve; obtaining the actual working current of the circuit breaker and deriving an adjustment coefficient of the basic life decay curve based on the relationship between the actual working current and the rated current, and adjusting the basic life decay curve to a real-time life decay curve based on the adjustment coefficient; obtaining the physical quantity of the moving contact during the closing and / or opening process, fitting the physical quantity to form a life physical quantity related to the real-time life decay curve, and combining the real-time life decay curve to calculate and determine the life status of the circuit breaker. A device for monitoring the life of a circuit breaker includes a single-chip microcomputer, an acceleration sensor, a gyroscope, and a data acquisition module. The present invention updates the life decay curve in real time and combines the physical quantity of the moving contact, the life decay curve, and the initial data to more accurately and effectively determine the status of the circuit breaker.

Description

Technical Field

[0001] The invention relates to a low-voltage circuit breaker, and in particular to a circuit breaker life monitoring method and device. Background Art

[0002] With the development of science and technology, the monitoring devices for the life and failure of circuit breakers are mostly equipped with single-chip microcomputers, which realize the reading and judgment of signal quantities. At present, the monitoring of the life and failure of circuit breakers mostly adopts the online monitoring method. Generally, the electrical life of the circuit breaker is used as an important indicator for monitoring the life of the circuit breaker, and the electrical life is calculated by collecting the current signal through the photoelectric sensor. However, the life of the circuit breaker includes mechanical life and electrical life. In the existing technology, most of them focus on the electrical life to reflect the life of the circuit breaker, and ignore the monitoring of the mechanical life. However, in actual production applications, mechanical wear will affect the electrical life. Therefore, this monitoring method that ignores the mechanical life and only relies on the electrical life to judge the life and failure of the circuit breaker has low accuracy and cannot accurately reflect the actual use of the circuit breaker. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects of the prior art and provide a circuit breaker life monitoring method and device with high accuracy.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A method for monitoring the life of a circuit breaker comprises the following steps:

[0006] Step S1: obtaining an original life decay curve under rated current conditions, storing the original life decay curve and using it as a basic life decay curve for the next update of the life decay curve;

[0007] Step S2: when the circuit breaker is closed and / or opened, the actual working current of the circuit breaker is obtained, and the adjustment coefficient of the basic life decay curve is derived according to the relationship between the actual working current and the rated current, and the basic life decay curve is adjusted to the real-time life decay curve according to the adjustment coefficient, and the real-time life decay curve is stored as the basic life decay curve when the life decay curve is updated next time;

[0008] Step S3: obtaining at least one physical quantity of the moving contact during the closing and / or opening process, wherein the physical quantity includes vibration frequency, amplitude, vibration time, angular velocity and displacement, and fitting at least one physical quantity to form a life physical quantity related to the real-time life decay curve, and calculating the real-time remaining life of the circuit breaker by combining the life physical quantity and the real-time life decay curve; the original life decay curve obtained in step S1 is related to the life physical quantity, and the life physical quantity in the original life decay curve and the life physical quantity in step S3 are fitted based on the same physical quantity.

[0009] Further, in step S3, the vibration frequency, amplitude and vibration time obtained during the closing and / or opening process of the moving contact are fitted as life physical quantities, and the real-time remaining life of the circuit breaker is calculated based on the life physical quantities and the real-time life decay curve.

[0010] Further, in step S3, the angular velocity and displacement obtained during the closing and / or opening process of the moving contact are fitted as life physical quantities, and the real-time remaining life of the circuit breaker is calculated based on the life physical quantities and the real-time life decay curve.

[0011] Further, in step S3, the vibration frequency, amplitude, vibration time, angular velocity and displacement obtained during the closing and / or opening process of the moving contact are fitted as life physical quantities, and the real-time remaining life of the circuit breaker is calculated based on the life physical quantities and the real-time life decay curve.

[0012] Further, in step S3, the vibration frequency, amplitude, vibration time, angular velocity and displacement of the moving contact during the closing and / or opening process are obtained, the vibration frequency, amplitude and vibration time are fitted as the first life physical quantity, and the first real-time remaining life is calculated by combining the first life physical quantity and the real-time life decay curve; the angular velocity and displacement are fitted as the second life physical quantity, and the second real-time remaining life is obtained by combining the second life physical quantity and the real-time life decay curve; the average value of the first real-time remaining life and the second real-time remaining life is obtained as the real-time remaining life.

[0013] Further, in step S1, under rated current, the circuit breaker is closed and opened multiple times, and the physical quantity of the moving contact is obtained every n times, where n is greater than or equal to 1. The obtained physical quantity of the moving contact is fitted to form a life physical quantity, and the life physical quantity is fitted with the number of circuit breaker operations to form a relationship curve as the original life attenuation curve.

[0014] Further, in step S3, the fault thresholds of the physical quantities are obtained, and the fault thresholds include a vibration frequency fault threshold, an amplitude fault threshold, a vibration time fault threshold, an angular velocity fault threshold, and a displacement fault threshold; the obtained vibration frequency, amplitude, vibration time, angular velocity, and displacement are respectively compared with the vibration frequency fault threshold, amplitude fault threshold, vibration time fault threshold, angular velocity fault threshold, and displacement fault threshold. If any one of the physical quantities exceeds the fault threshold, it is determined that the circuit breaker is in a fault state.

[0015] Further, in step S3, the fitted life physical quantity is compared with the life physical quantity fault threshold, and if the life physical quantity exceeds the life physical quantity fault threshold, it is determined that the circuit breaker is in a fault state.

[0016] A circuit breaker life monitoring device comprises a control unit installed on the circuit breaker, an acceleration sensor and a gyroscope installed on a moving contact of the circuit breaker, and a current sampling circuit connected to the control unit, wherein the control unit comprises a central processing unit and a storage unit of the central processing unit itself, or a central processing unit and a storage unit connected to the central processing unit, wherein the storage unit stores an original life decay curve and a real-time updated life decay curve;

[0017] The current sampling circuit is connected to the central processing unit, and the acceleration sensor and the gyroscope are respectively connected to the control unit. During the closing and / or opening process of the circuit breaker, the acceleration sensor transmits the vibration acceleration signal of the moving contact to the control unit, and the gyroscope transmits the displacement and angular velocity signals of the moving contact to the control unit. The control unit adopts the circuit breaker life monitoring method as described above to obtain the life status of the circuit breaker.

[0018] Furthermore, the storage unit stores a fault threshold, and the control unit compares the received vibration acceleration signal of the moving contact, the displacement and angular velocity signal of the moving contact with the fault threshold to determine whether the circuit breaker is in a fault state.

[0019] Furthermore, it also includes a power supply circuit and a data acquisition module respectively connected to the control unit, and the control unit, the power supply circuit and the data acquisition module are arranged on a circuit board, and the circuit board is installed on the side of the circuit breaker.

[0020] A method for monitoring the life of a circuit breaker of the present invention obtains an original life decay curve of the circuit breaker, updates the life decay curve by comparing the actual current with the rated current, obtains physical quantities when the moving contact is closed and / or opened under the actual current, and fits them into life physical quantities reflecting the electrical life, and combines the life physical quantities with the updated life decay curve to obtain the real-time remaining life of the electrical life of the reaction circuit breaker.

[0021] Preferably, the five physical quantities of vibration frequency, amplitude, vibration time, angular velocity and displacement are fitted into a life physical quantity reflecting the electrical life.

[0022] In addition, the vibration frequency, amplitude and vibration time of the moving contact when closing or / and opening are fitted as the first life physical quantity and combined with the real-time life decay curve to obtain the first real-time remaining life, and the angular velocity and displacement of the moving contact when closing or / and opening are fitted as the second life physical quantity and combined with the real-time life decay curve to obtain the second real-time remaining life. The life state and fault condition of the circuit breaker can be obtained by comparing and calculating only the first real-time remaining life with the original life decay curve of the circuit breaker, or by comparing and calculating only the second real-time remaining life with the original life decay curve of the circuit breaker, or by comparing and calculating the first real-time remaining life, the second real-time remaining life and the original life decay curve of the circuit breaker at the same time. However, the result obtained by considering the first real-time remaining life and the second real-time remaining life at the same time is the most accurate. It is preferred to use the results obtained by calculating the first real-time remaining life and the second real-time remaining life as the life physical quantity for calculating the real-time remaining life.

[0023] In addition, by comparing the life physical quantity with the life physical quantity fault threshold, or comparing the vibration frequency, amplitude, vibration time, angular velocity and displacement with the corresponding vibration frequency fault threshold, amplitude fault threshold, vibration time fault threshold, angular velocity fault threshold and displacement fault threshold, it is determined whether the circuit breaker has a fault. By comparing and analyzing the real-time remaining life with the original life decay curve of the circuit breaker, the life status and fault condition of the circuit breaker are obtained. This monitoring method that takes into account both the mechanical life and electrical life of the circuit breaker has higher accuracy.

[0024] A circuit breaker life monitoring device of the present invention has a control unit that stores and updates a life decay curve in real time. During the closing and / or opening process of a moving contact, the vibration frequency, amplitude, vibration time, angular velocity and displacement are transmitted to a single-chip microcomputer via a vibration acceleration sensor and a gyroscope respectively. The control unit obtains various physical quantities of the moving contact according to the signals transmitted by the vibration acceleration sensor and the gyroscope, obtains the life physical quantity reflecting the electrical life through calculation, and then obtains the life of the circuit breaker according to the life decay curve under real-time current. The circuit breaker has both mechanical life and electrical life taken into account, and can monitor the circuit breaker more accurately and effectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart of a circuit breaker life monitoring method of the present invention;

[0026] Figure 2 It is a schematic diagram of a life attenuation curve in a circuit breaker life monitoring method of the present invention;

[0027] Figure 3-5 It is a schematic diagram of a circuit breaker life monitoring device of the present invention. DETAILED DESCRIPTION

[0028] The following is combined with Figures 1 to 5 The given examples further illustrate the specific implementation of the circuit breaker life monitoring method and device of the present invention. The circuit breaker life monitoring method and device of the present invention are not limited to the description of the following examples.

[0029] A method for monitoring the life of a circuit breaker comprises the following steps:

[0030] Step S1: obtaining an original life decay curve under rated current conditions, storing the original life decay curve and using it as a basic life decay curve for the next update of the life decay curve;

[0031] Step S2: when the circuit breaker is closed and / or opened, the actual working current of the circuit breaker is obtained, and the adjustment coefficient of the basic life decay curve is derived according to the relationship between the actual working current and the rated current, and the basic life decay curve is adjusted to the real-time life decay curve according to the adjustment coefficient, and the real-time life decay curve is stored as the basic life decay curve when the life decay curve is updated next time;

[0032] Step S3: obtaining at least one physical quantity of the moving contact during the closing and / or opening process, wherein the physical quantity includes vibration frequency, amplitude, vibration time, angular velocity and displacement, and fitting at least one physical quantity to form a life physical quantity related to the real-time life decay curve, and calculating the real-time remaining life of the circuit breaker by combining the life physical quantity and the real-time life decay curve; the original life decay curve obtained in step S1 is related to the life physical quantity, and the life physical quantity in the original life decay curve and the life physical quantity in step S3 are fitted based on the same physical quantity.

[0033] A method for monitoring the life of a circuit breaker of the present invention obtains an original life decay curve of the circuit breaker, updates the life decay curve by comparing the actual current with the rated current, obtains physical quantities when the moving contact is closed and / or opened under the actual current, and fits them into life physical quantities reflecting the electrical life, and combines the life physical quantities with the updated life decay curve to obtain the real-time remaining life of the electrical life of the reaction circuit breaker.

[0034] Combined with Figure 1 Detailed introduction to the monitoring method of circuit breaker life:

[0035] Step S1: Obtain the original life decay curve under rated current conditions, store the original life decay curve and use the original life decay curve as the basic life decay curve when the life decay curve is updated next time; the remaining times in the original life decay curve are related to the life physical quantity, and the life physical quantity is related to the physical quantity of the moving contact during the closing and / or opening process, and the physical quantity includes one or more of the vibration frequency, amplitude, vibration time, angular velocity and displacement when the moving contact is closed and / or opened. The measurement of the physical quantity can be measured when the moving contact is closed or opened, or it can be measured when both are closed and opened.

[0036] The original life decay curve can be obtained from the manufacturer. It is known data and can be obtained by the manufacturer based on design requirements and multiple experimental fitting. The original life decay curve is established specifically by selecting a circuit breaker sample, closing and opening the circuit breaker multiple times at the rated current, and obtaining the physical quantity of the moving contact once every n times, where n is greater than or equal to 1. For example, the rated closing and opening times of the circuit breaker is 1 million times, and the circuit breaker is closed and opened 1 million times. The physical quantity of the moving contact is obtained at every 100 closing and opening times. The physical quantity can be measured when the moving contact is closed or opened, or when it is closed and opened. The physical quantity includes vibration frequency, amplitude, vibration time, angular velocity and displacement. One or more physical quantities of the moving contact are fitted to form a life physical quantity reflecting the mechanical life of the circuit breaker. The life physical quantity is fitted with the number of operations of the circuit breaker to form a relationship curve as the original life decay curve. Figure 2 As shown, the remaining times in the original life decay curve are inversely proportional to the life physical quantity. As the life physical quantity gradually increases, the remaining times of the circuit breaker gradually decreases. Figure 2 The linear original life decay curve is schematically given. In practice, the original life decay curve may be linear or curvilinear depending on the fitting method used. One fitting method is to use mat lab to fit the data and obtain a relationship curve.

[0037] Step S2: When the circuit breaker is closed and / or opened, the actual working current of the circuit breaker is obtained, and the adjustment coefficient of the basic life decay curve is derived according to the relationship between the actual working current and the rated current. For example, a formula of the adjustment coefficient is, adjustment coefficient M = rated current Ie / working current I, and the basic life decay curve is adjusted to a real-time life decay curve according to the adjustment coefficient, and the real-time life decay curve is stored as the basic life decay curve when the life decay curve is updated next time. Preferably, the actual working current is obtained at each closing and / or opening, and the actual working current can be obtained when the moving contact is closed or opened, or the working current at the time of closing and opening is obtained at the same time, and the adjustment coefficient of the basic life decay curve is derived according to the relationship between the actual working current obtained and the rated current, and the real-time life decay curve is adjusted according to the adjustment coefficient, and the adjusted real-time life decay curve is stored as the basic life decay curve when the life decay curve is updated when the moving contact of the circuit breaker is closed and / or opened next time. In this embodiment, the adjustment coefficient is determined based on the actual working current and the rated current. In the actual operation of the circuit breaker, the working voltage is relatively stable, and even if the working voltage changes, it can be reflected in the current according to I=U / R; of course, the adjustment coefficient can also adopt other adjustment coefficient formulas to obtain the adjustment coefficient based on the working current and the rated current.

[0038] Specifically, the adjustment coefficient derived from the relationship between the actual working current and the rated current cannot change the rate of change of the life decay curve; when the physical quantity of life is the same, if the actual working current is greater than the rated current, the corresponding remaining number on the actual life decay curve is less than the corresponding remaining number on the original life decay curve; if the actual working current is less than the rated current, the corresponding remaining number on the actual life decay curve is greater than the corresponding remaining number on the original life decay curve. Figure 2 Specifically, with the life physical quantity as the x-axis and the remaining number of times of the circuit breaker as the y-axis, under the rated current, the original life decay curve is a straight line whose y value decreases as the x value increases. Of course, the life decay curve can also be a curve. After adjustment according to the adjustment coefficient, the real-time life decay curve is a straight line parallel to the original life decay curve, which means that the adjustment coefficient cannot change the rate of change of the life decay curve. When the actual current is greater than the rated current, the real-time life decay curve is closer to the x-axis than the original life decay curve. In this way, under the condition of the same life physical quantity, the corresponding remaining number is smaller, that is, the adjustment coefficient is less than 1; when the actual current is less than the rated current, the real-time life decay curve is farther away from the x-axis than the original life decay curve. In this way, under the condition of the same life physical quantity, the corresponding remaining number is larger, that is, the adjustment coefficient is greater than 1.

[0039] Step S3: In the closing and / or opening process of updating the life decay curve, obtain the physical quantity of the moving contact in the closing and opening process, the physical quantity includes vibration frequency, amplitude, vibration time, angular velocity and displacement, at least one of which is fitted to form a life physical quantity reflecting the electrical life, and the real-time remaining life of the electrical life of the reaction circuit breaker is obtained by calculation in combination with the life physical quantity and the real-time decay curve. The original life decay curve obtained in step S1 is related to the life physical quantity, and the life physical quantity in the original life decay curve and the life physical quantity in step S3 are obtained by fitting based on the same physical quantity. Preferably, the life physical quantity formed by fitting the five physical quantities of vibration frequency, amplitude, vibration time, angular velocity and displacement is adopted, and the original life decay curve in step S1 is also obtained by fitting based on the same five physical quantities and methods.

[0040] Furthermore, the real-time remaining life is compared with the original life decay curve of the circuit breaker to analyze and calculate the life status of the circuit breaker to see whether the circuit breaker is overloaded or in a healthy state.

[0041] Specifically, in combination with the above steps, a first embodiment is provided. In step S3, the vibration frequency, amplitude and vibration time obtained during the closing and / or opening process of the moving contact are fitted as life physical quantities, and the real-time remaining life is obtained based on the life physical quantities and the real-time life decay curve. One fitting method for the life physical quantity is to obtain the vibration frequency, amplitude and vibration time of the measuring acceleration sensor of the moving contact, and adjust the three values ​​to the same order of magnitude and then perform averaging to obtain the life physical quantity, and calculate the real-time remaining life based on the life physical quantity and the real-time life decay curve.

[0042] A second embodiment similar to the first embodiment is provided, in step S3, the angular velocity and displacement of the moving contact during the closing and / or opening process are fitted as life physical quantities, and the real-time remaining life is obtained according to the life physical quantity and the real-time life decay curve. Similarly, a fitting method for the life physical quantity is to obtain the measured angular velocity and displacement of the moving contact, and adjust the values ​​of the two to the same order of magnitude and then calculate the average value.

[0043] A third embodiment is provided, in which the vibration frequency, amplitude and vibration time obtained during the closing and / or opening process of the moving contact are fitted as the first life physical quantity, and the first life physical quantity is combined with the real-time remaining life curve to obtain the first real-time remaining life; the angular velocity and displacement are fitted as the second life physical quantity, and the second life physical quantity is combined with the real-time remaining life curve to obtain the second real-time remaining life, and the fitting of the first life physical quantity and the second life physical quantity is the same as the first embodiment and the second embodiment. The obtained first real-time remaining life and the second real-time remaining life are comprehensively considered to obtain a more accurate real-time remaining life, and the average value of the first real-time remaining life and the second real-time remaining life is preferably obtained as the real-time remaining life of the circuit breaker, which is conducive to obtaining a more accurate result. Considering the first real-time remaining life and the second real-time remaining life at the same time can improve the monitoring accuracy, but it is not limited to the calculation using the average value of the two, and it can also be calculated by focusing on the first real-time remaining life or the second real-time remaining life, that is, calculated according to the corresponding weight coefficient.

[0044] A fourth embodiment is provided. In step S3, the vibration frequency, amplitude, vibration time, angular velocity and displacement obtained during the closing and / or opening process of the moving contact are fitted as life physical quantities, and the real-time remaining life is obtained based on the life physical quantities and the real-time life decay curve. A fitting method for the life physical quantities is to obtain the vibration frequency, amplitude, vibration time, angular velocity and displacement, and adjust the five values ​​to the same order of magnitude and then perform averaging to obtain the life physical quantity, and calculate the real-time remaining life based on the life physical quantity and the real-time life decay curve.

[0045] Furthermore, the fault condition of the circuit breaker is determined by comparing the real-time life physical quantity with the life physical quantity threshold. When a mechanical failure occurs in the circuit breaker, the acquired physical quantity will change, and the fault threshold related to the physical quantity can be compared to obtain the mechanical life of the circuit breaker.

[0046] Preferably, a circuit breaker fault judgment is performed in step S3, and a first fault judgment method is specifically provided to obtain a fault threshold of a physical quantity, wherein the fault threshold includes one or more of a vibration frequency fault threshold, an amplitude fault threshold, a vibration time fault threshold, an angular velocity fault threshold, and a displacement fault threshold. The fault threshold is a known value, and the fault threshold can be obtained through multiple tests. The obtained physical quantities, i.e., the vibration frequency, amplitude, vibration time, angular velocity, and displacement, are respectively compared with the vibration frequency fault threshold, amplitude fault threshold, vibration time fault threshold, angular velocity fault threshold, and displacement fault threshold. When any one of the physical quantities exceeds the fault threshold, it is judged that the circuit breaker is in a fault state.

[0047] Of course, the fault judgment of the circuit breaker can also be like the second method, obtaining the life physical quantity fault threshold, comparing the fitted life physical quantity with the life physical quantity fault threshold, and judging that the circuit breaker is in a fault state if the life physical quantity exceeds the life physical quantity fault threshold. The life physical quantity fault threshold is a known value, and the life physical quantity fault threshold can be obtained by adjusting a certain coefficient through multiple test results.

[0048] based on Figure 1-2 The proposed circuit breaker life monitoring method provides a device for implementing the above monitoring method, such as Figure 3-5 As shown, a circuit breaker life and fault monitoring device includes a control unit installed on the circuit breaker, an acceleration sensor and a gyroscope installed on the moving contact of the circuit breaker, a current sampling circuit connected to the control unit, and the acceleration sensor and the gyroscope are connected to the control unit.

[0049] The control unit includes a central processing unit and a storage unit of the central unit itself, or a central processing unit and a storage unit connected to the central processing unit. The storage unit stores initial data of the circuit breaker and a life decay curve updated in real time. The initial data includes an original life decay curve of the moving contact in the original state during the closing and / or opening process and a fault threshold. The fault threshold includes a physical quantity fault threshold obtained by direct measurement and a life physical quantity fault threshold after physical quantity fitting; the physical quantity fault threshold includes a vibration acceleration physical fault threshold of the moving contact, including a vibration frequency fault threshold, an amplitude fault threshold, a vibration time fault threshold, an angular velocity fault threshold and a displacement fault threshold of the moving contact.

[0050] The current sampling circuit is connected to a central processing unit, and the central processing unit obtains an actual working current according to a current signal transmitted by the current sampling circuit, and calculates and updates a stored life decay curve according to the actual working current and the rated current; the acceleration sensor and the gyroscope are respectively connected to a control unit, and during the closing and / or opening process of the circuit breaker, the acceleration sensor transmits a vibration acceleration signal of the moving contact to the control unit, and the gyroscope transmits a displacement angular velocity signal of the moving contact to the control unit, and the central processing module of the control unit obtains a life physical quantity by combining the acceleration signal and the displacement angular velocity signal of the moving contact, and outputs data to a data acquisition module by calculating and judging the life state and fault condition of the circuit breaker based on the life physical quantity, the updated life decay curve and the fault threshold.

[0051] The control unit in the present invention can be a single chip microcomputer including a central processing unit and a storage unit, or a separate microprocessor as a central processing unit combined with a separate storage unit, both of which are commercially available products. The acceleration sensor and gyroscope in the present invention are both commercially available products. For example, the acceleration sensor can be a voltage acceleration sensor, a capacitive acceleration sensor, an inductive acceleration sensor, a strain acceleration sensor or a piezoresistive acceleration sensor. The current sampling circuit includes a current transformer and a current signal processing circuit connected to the circuit transformer and the control unit, and performs filtering and rectification processing, which belongs to the prior art in this field and will not be repeated.

[0052] Combination Figure 3-5 In the embodiment, the control unit is a single-chip microcomputer, and includes a central processing unit and a storage unit. The acceleration sensor transmits a vibration acceleration signal to the single-chip microcomputer, and the mechanical vibration waveform is composed of a series of attenuated sine waves. The corresponding amplitude of the external vibration is proportional to the magnitude of the impact force. The maximum response vibration signal corresponds to the closing moment of the moving contact of the circuit breaker. The movement of the moving contact is reflected by the vibration acceleration frequency and duration. The vibration frequency, amplitude and vibration time can be obtained through the vibration acceleration signal. The vibration acceleration signal of the vibration acceleration sensor is input into the single-chip microcomputer and fitted into a life physical quantity reflecting the electrical life through calculation. The life physical quantity is then combined with the life decay curve to calculate the electrical life of the moving contact. The single-chip microcomputer compares the calculated electrical life with the original life decay curve to obtain the life state of the circuit breaker at this time; the physical quantity or the physical fit life physical quantity is compared with the fault threshold to obtain whether the circuit breaker is in a fault state. Of course, the vibration acceleration signal can be filtered, amplified and other signal processing before being input into the single-chip microcomputer. At this time, a signal processing circuit is set between the acceleration sensor and the single-chip microcomputer. The vibration frequency and duration are obtained according to the number, start time and end time of the received sine waves, and the amplitude can be obtained according to the maximum value or average value of the amplitude of each sine wave or other mean value calculation method.

[0053] The gyroscope sensor measures the displacement and angular velocity and transmits the displacement angular velocity signal to the single-chip microcomputer. The angular velocity and displacement can be obtained through the displacement angular velocity signal. The single-chip microcomputer fits the displacement angular velocity signal to a life physical quantity reflecting the electrical life through calculation, and then combines the life physical quantity with the life decay curve to calculate the electrical life of the moving contact. The single-chip microcomputer then compares the calculated electrical life with the original life decay curve of the circuit breaker to obtain the life state of the circuit breaker at this time. At the same time, the angular velocity and displacement measured in real time by the gyroscope are compared with the angular velocity fault threshold and displacement fault threshold of the moving contact in the fault threshold to obtain the fault situation. Of course, the displacement angular velocity signal can be filtered, amplified and other signal processing before being input into the single-chip microcomputer.

[0054] Specific as Figure 3 As shown, a control unit, a power supply circuit, a data acquisition module, etc. are arranged on a circuit board, and the circuit board is installed on the side of the circuit breaker. The single-chip microcomputer is connected to a power supply circuit for powering the single-chip microcomputer and a data acquisition module connected to the single-chip microcomputer for acquiring data of the single-chip microcomputer. The data acquisition module is a communication interface and / or a display interface; an acceleration sensor and a gyroscope are installed on the moving contact of the circuit breaker. The acceleration sensor and the gyroscope can be powered by the existing power supply method of the circuit breaker or by the power supply circuit on the circuit board. The main circuit of the circuit breaker passes through the current transformer of the current sampling circuit. The acceleration sensor and The gyroscope is connected to the single-chip microcomputer through a lead, the current transformer is connected to the single-chip microcomputer through a current signal processing circuit, the acceleration sensor and the gyroscope are connected to the single-chip microcomputer through their respective signal processing circuits, the current signal processing circuit and the signal processing circuit are both arranged on a circuit board, and the central processing unit of the single-chip microcomputer determines the life state and fault condition of the circuit breaker only according to the vibration acceleration signal and the life attenuation curve of the moving contact, or only according to the displacement angular velocity signal and the life attenuation curve of the moving contact, or according to the vibration acceleration signal and the displacement angular velocity signal of the moving contact and the life attenuation curve.

[0055] The present invention provides a circuit breaker life monitoring device, wherein the control unit stores and updates the life decay curve in real time. During the closing and / or opening process of the moving contact, the vibration acceleration signal and the displacement angular velocity signal are respectively transmitted to the control unit through the vibration acceleration sensor and the gyroscope. When the control unit obtains the vibration frequency, amplitude, vibration time, angular velocity and displacement according to the signals transmitted by the vibration acceleration sensor and the gyroscope, the life physical quantity of the reaction electrical life of the moving contact is calculated, and then the electrical life of the circuit breaker is obtained by analyzing and calculating the life decay curve formed by combining with the current; at the same time, the fault condition of the circuit breaker is obtained by obtaining the physical quantity of the moving contact during the closing and / or opening process or fitting the physical quantity and comparing it with the fault threshold value. The physical quantity reflects the mechanical life of the circuit breaker, and takes into account the mechanical life and electrical life of the circuit breaker, so that the circuit breaker can be monitored more accurately and effectively.

[0056] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A circuit breaker life monitoring method, characterized in that: The steps include: Step S1: obtaining an original life decay curve under rated current conditions, storing the original life decay curve and using it as a basic life decay curve for the next update of the life decay curve; Step S2: when the circuit breaker is closed and / or opened, the actual working current of the circuit breaker is obtained, and the adjustment coefficient of the basic life decay curve is derived according to the relationship between the actual working current and the rated current, and the basic life decay curve is adjusted to the real-time life decay curve according to the adjustment coefficient, and the real-time life decay curve is stored as the basic life decay curve when the life decay curve is updated next time; Step S3: obtaining at least one physical quantity of the moving contact during the closing and / or opening process, wherein the physical quantity includes vibration frequency, amplitude, vibration time, angular velocity and displacement, and fitting at least one physical quantity to form a life physical quantity related to the real-time life decay curve, and calculating the real-time remaining life of the circuit breaker by combining the life physical quantity and the real-time life decay curve; the original life decay curve obtained in step S1 is related to the life physical quantity, and the life physical quantity in the original life decay curve and the life physical quantity in step S3 are fitted based on the same physical quantity.

2. A circuit breaker life monitoring method according to claim 1, characterized in that: In step S3, the vibration frequency, amplitude and vibration time obtained during the closing and / or opening process of the moving contact are fitted as life physical quantities, and the real-time remaining life of the circuit breaker is calculated based on the life physical quantities and the real-time life decay curve.

3. A circuit breaker life monitoring method according to claim 1, characterized in that: In step S3, the angular velocity and displacement obtained during the closing and / or opening process of the moving contact are fitted as life physical quantities, and the real-time remaining life of the circuit breaker is calculated based on the life physical quantities and the real-time life decay curve.

4. A circuit breaker life monitoring method according to claim 1, characterized in that: In step S3, the vibration frequency, amplitude, vibration time, angular velocity and displacement obtained during the closing and / or opening process of the moving contact are fitted as life physical quantities, and the real-time remaining life of the circuit breaker is calculated based on the life physical quantities and the real-time life decay curve.

5. A circuit breaker life monitoring method according to claim 1, characterized in that: In step S3, the vibration frequency, amplitude, vibration time, angular velocity and displacement of the moving contact during the closing and / or opening process are obtained, the vibration frequency, amplitude and vibration time are fitted as the first life physical quantity, and the first real-time remaining life is calculated by combining the first life physical quantity and the real-time life decay curve; the angular velocity and displacement are fitted as the second life physical quantity, and the second real-time remaining life is obtained by combining the second life physical quantity and the real-time life decay curve; the average value of the first real-time remaining life and the second real-time remaining life is obtained as the real-time remaining life.

6. A circuit breaker life monitoring method according to claim 1, characterized in that: In step S1, under rated current, the circuit breaker is closed and opened multiple times, and the physical quantity of the moving contact is obtained every n times, where n is greater than or equal to 1. The obtained physical quantity of the moving contact is fitted to form a life physical quantity, and the life physical quantity is fitted with the number of circuit breaker operations to form a relationship curve as the original life attenuation curve.

7. A circuit breaker life monitoring method according to claim 1, characterized in that: In step S3, the fault thresholds of the physical quantities are obtained, and the fault thresholds include a vibration frequency fault threshold, an amplitude fault threshold, a vibration time fault threshold, an angular velocity fault threshold, and a displacement fault threshold; the obtained vibration frequency, amplitude, vibration time, angular velocity, and displacement are respectively compared with the vibration frequency fault threshold, amplitude fault threshold, vibration time fault threshold, angular velocity fault threshold, and displacement fault threshold. If any one of the physical quantities exceeds the fault threshold, it is determined that the circuit breaker is in a fault state.

8. A circuit breaker life monitoring method according to claim 1, characterized in that: In step S3, the fitted life physical quantity is compared with the life physical quantity fault threshold, and if the life physical quantity exceeds the life physical quantity fault threshold, it is determined that the circuit breaker is in a fault state.

9. A circuit breaker life monitoring device, characterized in that: It includes a control unit installed on the circuit breaker, an acceleration sensor and a gyroscope installed on the moving contact of the circuit breaker, and a current sampling circuit connected to the control unit. The control unit includes a central processing unit and a storage unit of the central unit itself, or a central processing unit and a storage unit connected to the central processing unit. The storage unit stores an original life decay curve and a real-time updated life decay curve; The current sampling circuit is connected to the central processing unit, and the acceleration sensor and the gyroscope are respectively connected to the control unit. During the closing and / or opening process of the circuit breaker, the acceleration sensor transmits the vibration acceleration signal of the moving contact to the control unit, and the gyroscope transmits the displacement and angular velocity signals of the moving contact to the control unit. The control unit adopts the circuit breaker life monitoring method described in any one of claims 1-8 to obtain the life status of the circuit breaker.

10. A circuit breaker life monitoring device according to claim 9, characterized in that: The storage unit stores a fault threshold, and the control unit compares the received vibration acceleration signal of the moving contact, the displacement and angular velocity signal of the moving contact with the fault threshold to determine whether the circuit breaker is in a fault state.

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