Circuit breaker opening and closing state change monitoring method and monitoring system

Abstract

The invention relates to a circuit breaker opening and closing state change monitoring method and monitoring system, and the method comprises the steps: building a comprehensive signal library through historical vibration signals and historical electric field signals of a circuit breaker in an opening and closing state, and enabling the historical vibration signals to comprise clutter signals, normal vibration signals and abnormal vibration signals; the abnormal vibration signals comprise vibration signals under various types of faults; real-time vibration signals generated in the opening and closing process of the circuit breaker are obtained, and whether the opening and closing state of the circuit breaker is normal or not is determined by conducting consistency comparison on the real-time vibration signals and historical vibration signals in a comprehensive signal library; establishing an electric field intensity criterion through integrating historical electric field signals in the signal library, obtaining real-time electric field signals in the opening and closing process of the circuit breaker, and determining whether the opening and closing state of the circuit breaker is normal or not according to the electric field intensity criterion and the real-time electric field signals. Through vibration and electromagnetic field sensing, the on-off state change of the circuit breaker can be monitored, and the on-off state analysis result of the circuit breaker is provided.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric power equipment, and in particular relates to a method and a system for monitoring changes in the opening and closing states of a circuit breaker. Background Art

[0002] As the operating voltage level of the power system continues to increase, the capacity and number of high-voltage circuit breakers continue to increase. Therefore, it is very important to judge their operating reliability. The opening and closing operations of high-voltage circuit breakers are completed by the operating mechanism controlling the movement of each component in sequence, and determining whether it can successfully open and close the line. Therefore, once a circuit breaker fails, it will cause power supply problems, and the health of the circuit breaker is very important.

[0003] The operating mechanism of the existing circuit breaker is prone to various faults during frequent opening and closing actions. The existing monitoring methods mostly use manual inspections, which are prone to missed judgments. At the same time, they cannot more accurately identify problems with the circuit breaker, and are prone to over-maintenance or under-maintenance.

[0004] In order to accelerate the construction of digital and intelligent operation and maintenance systems and conform to the operation and maintenance management model of centralized control stations, the judgment of equipment status must also be developed from the previous manual observation to the deployment of various sensors, detection equipment and advanced detection technologies to obtain the real-time status of equipment status. In this context, it is of great significance to provide physical quantities other than conventional electrical quantities for the circuit breaker opening and closing states as independent criteria to help the digitalization and informatization of operation and maintenance work. For this reason, a method and system for monitoring changes in the opening and closing states of circuit breakers are urgently needed. Summary of the invention

[0005] The present invention provides a circuit breaker opening and closing state change monitoring method and monitoring system, which realize circuit breaker opening and closing state change monitoring through vibration and electromagnetic field perception, and provide circuit breaker opening and closing state analysis results, thereby solving the technical problems mentioned in the background technology.

[0006] A technical solution of the present invention is as follows: A method for monitoring the change of the opening and closing state of a circuit breaker, comprising: S10: Establishing a comprehensive signal library through historical vibration signals and historical electric field signals in the circuit breaker opening and closing states, wherein the historical vibration signals include clutter signals, normal vibration signals and abnormal vibration signals, and the abnormal vibration signals include vibration signals under various types of faults; S20: acquiring a real-time vibration signal generated during the opening and closing process of the circuit breaker, and determining whether the opening and closing state of the circuit breaker is normal by comparing the real-time vibration signal with the historical vibration signal in the comprehensive signal library; S30: Establish an electric field strength criterion by synthesizing historical electric field signals in the signal library, obtain real-time electric field signals during the opening and closing process of the circuit breaker, and determine whether the opening and closing state of the circuit breaker is normal based on the electric field strength criterion and the real-time electric field signal.

[0007] Furthermore, the step S20 includes: Obtain real-time vibration signals of the circuit breaker beam position, A phase position, B phase position and C phase position; The state characteristic quantities of the real-time vibration signals of the circuit breaker crossbeam position, A phase position, B phase position and C phase position are extracted respectively; All state feature quantities are compared for consistency with historical vibration signals in the comprehensive signal library through a correlation test method to determine whether the real-time vibration signal corresponding to the state feature quantity belongs to one of a noise signal, a normal vibration signal and an abnormal vibration signal.

[0008] Further, including: Performing a first correlation test on the state feature quantity and the state feature quantity of the clutter signal to obtain a first correlation degree, and when the first correlation degree is greater than a correlation threshold, determining that the real-time vibration signal corresponding to the state feature quantity belongs to the clutter signal; When the correlation is less than the correlation threshold, a second correlation test is performed on the state feature quantity and the state feature quantity of the normal vibration signal to obtain a second correlation; when the second correlation is greater than the correlation threshold, it is determined that the real-time vibration signal corresponding to the state feature quantity belongs to a normal vibration signal, and it is determined that the current circuit breaker opening and closing state is normal; When the second correlation is less than the correlation threshold, it is determined that the current circuit breaker opening and closing state is abnormal.

[0009] Further, including: Correlation checks are performed on the state characteristic quantity and the vibration signals under various types of faults to determine the fault type corresponding to the real-time vibration signal.

[0010] Further, including: When the real-time vibration signal corresponding to the state characteristic quantity belongs to a normal vibration signal, data parameters of the real-time vibration signal are extracted, and when the data parameters are greater than a warning threshold, an alarm is issued.

[0011] Further, including: Perform zero drift adjustment on the acquired real-time vibration signal.

[0012] Furthermore, the step S30 includes: Acquire the real-time electric field signal of the circuit breaker at the end of the three-phase porcelain insulation of the circuit breaker and the real-time electric field signal of the current transformer at the end of the three-phase porcelain insulation of the connected current transformer; Establishing a circuit breaker electric field strength graph according to the circuit breaker real-time electric field signal, and establishing a current transformer electric field strength graph according to the current transformer real-time electric field signal; According to the electric field strength criterion, the circuit breaker electric field strength graph and the current transformer electric field strength graph, it is determined whether the circuit breaker opening and closing states are normal and whether the circuit breaker and the current transformer are damaged in insulation.

[0013] Furthermore, the electric field strength criterion includes: When the circuit breaker electric field strength graph and the current transformer electric field strength graph are both symmetrically distributed in the center, the circuit breaker is in a closed state; When the electric field strength graph of the circuit breaker and the electric field strength graph of the current transformer are both in a straight line distribution, the circuit breaker is in an open state and the connected current transformer is in a power-off state; When the circuit breaker electric field strength graph and the current transformer electric field strength graph are both symmetrically distributed in the center and the maximum value of the circuit breaker electric field strength is lower than the maximum value of the current transformer electric field strength, the circuit breaker is in an open state and the connected current transformer is in a energized state; When the electric field strength graph of the circuit breaker and the electric field strength graph of the current transformer are both in an irregular state, the circuit breaker or the connected current transformer is in an insulation damaged state.

[0014] Another technical solution of the present invention is as follows: a circuit breaker opening and closing state change monitoring system, used to execute any of the above-mentioned circuit breaker opening and closing state change monitoring methods, comprising: Vibration sensor, used to obtain real-time vibration signals generated during the opening and closing process of the circuit breaker; Electric field sensor, used to obtain real-time electric field signals during the opening and closing process of the circuit breaker; The processing module is used to determine whether the opening and closing state of the circuit breaker is normal by comparing the real-time vibration signal with the historical vibration signal in the comprehensive signal library for consistency, and determine whether the opening and closing state of the circuit breaker is normal based on the electric field strength criterion and the real-time electric field signal.

[0015] Furthermore, it also includes an alarm device, which is communicatively connected to the processing module and is used for alarming under the control of the processing module.

[0016] Beneficial effects of the present invention: The present invention can monitor the change of the circuit breaker's opening and closing state through the vibration signal during the mechanical opening and closing action of the circuit breaker, and can also analyze and compare the vibration signal to find potential mechanical faults such as the circuit breaker's three-phase opening and closing at different times and the three-phase inconsistency. By arranging electric field strength sensors near the three-phase porcelain insulation ends of the circuit breaker and the three-phase porcelain insulation ends of the connected current transformer, the electric field strength of the three-phase measurement points of the circuit breaker and the connected current transformer is continuously obtained, thereby achieving real-time monitoring of the change of the circuit breaker's opening and closing state and further detecting the circuit breaker or the connected current transformer insulation damage fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention provides a flow chart of a method for monitoring the change of the opening and closing states of a circuit breaker.

[0018] Figure 2 This is a flow chart of vibration signal analysis according to the present invention.

[0019] Figure 3 The present invention is a block diagram of a circuit breaker opening and closing state change monitoring system. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. The described embodiment is only a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0021] In one technical solution of the present invention, Figure 1 1 is a flow chart provided by a method for monitoring the change of the opening and closing states of a circuit breaker according to the present invention, such as Figure 1 As shown, the present invention includes: S10: Establish a comprehensive signal library through historical vibration signals and historical electric field signals under the circuit breaker opening and closing states, wherein the historical vibration signals include noise signals, normal vibration signals and abnormal vibration signals, and the abnormal vibration signals include vibration signals under various types of faults.

[0022] The comprehensive signal library adopts hierarchical and fault tree reasoning diagnosis model, combined with fault threshold analysis, and configures expert information library to complete the monitoring of circuit breaker opening and closing status and fault monitoring. PowerBuilder 6.5 is used as the application development tool, and the high-performance database platform Sybase 11 is used to optimize the design of the database and knowledge base in the comprehensive signal library.

[0023] S20: acquiring a real-time vibration signal generated during the opening and closing process of the circuit breaker, and determining whether the opening and closing state of the circuit breaker is normal by comparing the real-time vibration signal with the historical vibration signal in the comprehensive signal library for consistency.

[0024] There are many mechanical components in high-voltage circuit breakers. When opening and closing, each structural component vibrates, generating a large number of vibration signals. The acquisition of vibration signals during opening and closing can directly monitor the changes in the opening and closing state of the circuit breaker. Analysis and comparison of vibration signals can also find potential mechanical faults such as the three-phase opening and closing of the circuit breaker at different times and the inconsistency of the three phases. The vibration signal acquisition of the on-site circuit breaker was analyzed and it was found that the vibration process of the circuit breaker is divided into three stages: first, the spring, pull rod, crank arm and other components are subjected to force to produce large-amplitude forced vibration, then the crossbeam, porcelain sleeve, bolt and other stable components produce small-amplitude free vibration, and then the power frequency vibration generated under working conditions. The vibration amplitudes of the three vibration signals are very different. The current opening and closing state of the circuit breaker can be quickly distinguished by analyzing the vibration signals. The vibration signals collected by sensors at different positions are compared and analyzed in the comprehensive signal library, and the state characteristic quantities of each vibration signal are calculated. The correlation test method is used to check the consistency of each signal, and the comprehensive signal library is analyzed.

[0025] The specific process of the present invention is as follows: Obtain real-time vibration signals of the circuit breaker beam position, phase A position, phase B position, and phase C position. It should be noted that with changes in temperature and other environmental conditions, the zero point of the collected quantity may drift, so it is necessary to adjust the zero drift of the acquired real-time vibration signal.

[0026] The state feature quantities of the real-time vibration signals of the circuit breaker crossbeam position, A phase position, B phase position and C phase position are extracted respectively.

[0027] The vibration signal of the circuit breaker in the open and closed state contains the status information of the mechanical components, from which the working status of each structural component can be extracted. In order to capture the vibration signal, a sensor needs to be installed at the crossbeam, A, B, and C positions of the circuit breaker to collect the vibration signal.

[0028] All state feature quantities are compared for consistency with historical vibration signals in the comprehensive signal library through a correlation test method to determine whether the real-time vibration signal corresponding to the state feature quantity belongs to one of a noise signal, a normal vibration signal and an abnormal vibration signal.

[0029] Specific process, such as Figure 2 As shown, including: A first correlation test is performed on the state feature quantity and the state feature quantity of the clutter signal to obtain a first correlation degree. When the first correlation degree is greater than a correlation threshold, it is determined that the real-time vibration signal corresponding to the state feature quantity belongs to the clutter signal.

[0030] When the correlation is less than the correlation threshold, a second correlation test is performed on the state characteristic quantity and the state characteristic quantity of the normal vibration signal to obtain a second correlation. When the second correlation is greater than the correlation threshold, it is determined that the real-time vibration signal corresponding to the state characteristic quantity belongs to a normal vibration signal, and it is determined that the current circuit breaker opening and closing state is normal.

[0031] When the real-time vibration signal corresponding to the state characteristic quantity belongs to a normal vibration signal, the data parameter of the real-time vibration signal is extracted, and when the data parameter is greater than a warning threshold, an alarm is issued.

[0032] The critical parameters of the circuit breaker are set with safety thresholds. When the monitoring data exceeds the preset threshold, the system will automatically issue an alarm. Real-time monitoring of the critical parameters of the circuit breaker and the connected current transformer. Once the abnormal parameters reach or exceed the preset warning value, the system will immediately issue a fault warning, record the historical data and alarm information of the circuit breaker, and notify the operation and maintenance personnel to handle it in time.

[0033] When the second correlation is less than the correlation threshold, it is determined that the current circuit breaker opening and closing state is abnormal.

[0034] Correlation checks are performed on the state characteristic quantity and the vibration signals under various types of faults to determine the fault type corresponding to the real-time vibration signal.

[0035] S30: Establish an electric field strength criterion by synthesizing historical electric field signals in the signal library, obtain real-time electric field signals during the opening and closing process of the circuit breaker, and determine whether the opening and closing state of the circuit breaker is normal based on the electric field strength criterion and the real-time electric field signal.

[0036] When the circuit breaker is in the opening and closing state, the electric field strength of the circuit breaker will change. The opening and closing state of the circuit breaker can be analyzed by analyzing the electric field strength of the circuit breaker.

[0037] The specific process includes: The real-time electric field signal of the circuit breaker at the end of the three-phase porcelain insulation of the circuit breaker and the real-time electric field signal of the current transformer at the end of the three-phase porcelain insulation of the connected current transformer are obtained.

[0038] The circuit breaker electric field strength graph is established according to the real-time electric field signal of the circuit breaker, and the current transformer electric field strength graph is established according to the real-time electric field signal of the current transformer.

[0039] According to the electric field strength criterion, the circuit breaker electric field strength graph and the current transformer electric field strength graph, it is determined whether the circuit breaker opening and closing states are normal and whether the circuit breaker and the current transformer are damaged in insulation.

[0040] Wherein, the electric field strength criterion includes: When the circuit breaker electric field strength graph and the current transformer electric field strength graph are both symmetrically distributed in the center, the circuit breaker is in a closed state.

[0041] When the circuit breaker is in the closed state, the electric field strength at the three-phase porcelain insulation ends of the circuit breaker and the three-phase porcelain insulation ends of the connected current transformer are symmetrically distributed in the center.

[0042] When the circuit breaker electric field strength graph and the current transformer electric field strength graph are both in a straight line distribution, the circuit breaker is in an open state and the connected current transformer is in a power-off state.

[0043] When the circuit breaker is opened and the connected current transformer is de-energized, the electric field strength at the three-phase porcelain insulation ends of the circuit breaker and the three-phase porcelain insulation ends of the connected current transformer fluctuates in a straight line distribution.

[0044] When the circuit breaker electric field strength graph and the current transformer electric field strength graph are both centrally symmetrically distributed and the maximum value of the circuit breaker electric field strength is lower than the maximum value of the current transformer electric field strength, the circuit breaker is in an open state and the connected current transformer is in a energized state.

[0045] When the circuit breaker is open and the connected current transformer is energized, the electric field strengths at the three-phase porcelain insulation ends of the circuit breaker and the three-phase porcelain insulation ends of the connected current transformer are symmetrically distributed in the center, and the circuit breaker electric field is lower than the connected current transformer electric field.

[0046] When the electric field strength graph of the circuit breaker and the electric field strength graph of the current transformer are both in an irregular state, the circuit breaker or the connected current transformer is in an insulation damaged state.

[0047] When the insulation of the circuit breaker or the connected current transformer is damaged, the centered symmetry of the electric field strength at the ends of the three-phase porcelain insulation of the circuit breaker and the connected current transformer is destroyed, and the change trend of the three-phase electric field strength changes irregularly.

[0048] In another technical solution of the present invention, Figure 3 The present invention is a structural block diagram of a circuit breaker opening and closing state change monitoring system provided by the present invention, which is used in any of the above-mentioned circuit breaker opening and closing state change monitoring methods. The present invention includes: Vibration sensor 2, used to obtain real-time vibration signals generated during the opening and closing process of the circuit breaker, wherein the installation positions are the crossbeam position of the circuit breaker, the A phase position, the B phase position and the C phase position; The electric field sensor 3 is used to obtain the real-time electric field signal during the opening and closing process of the circuit breaker, wherein the installation position is the circuit breaker at the three-phase porcelain insulation end of the circuit breaker and the three-phase porcelain insulation end of the connected current transformer; The processing module 1 is used to determine whether the opening and closing state of the circuit breaker is normal by comparing the real-time vibration signal with the historical vibration signal in the comprehensive signal library for consistency, and determine whether the opening and closing state of the circuit breaker is normal according to the electric field strength criterion and the real-time electric field signal. The processing module can specifically adopt a processor such as a CPU and a DSP.

[0049] The technical solution further includes an alarm device 4 , which is in communication with the processing module 1 and is used for generating an alarm under the control of the processing module 1 .

[0050] The beneficial effects of this technical solution are the same as those of the circuit breaker opening and closing state change monitoring method, so they will not be described in detail here.

[0051] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for monitoring the change of the opening and closing state of a circuit breaker, characterized in that: include: S10: Establishing a comprehensive signal library through historical vibration signals and historical electric field signals in the circuit breaker opening and closing states, wherein the historical vibration signals include clutter signals, normal vibration signals and abnormal vibration signals, and the abnormal vibration signals include vibration signals under various types of faults; S20: acquiring a real-time vibration signal generated during the opening and closing process of the circuit breaker, and determining whether the opening and closing state of the circuit breaker is normal by comparing the real-time vibration signal with the historical vibration signal in the comprehensive signal library; S30: Establish an electric field strength criterion by synthesizing historical electric field signals in the signal library, obtain real-time electric field signals during the opening and closing process of the circuit breaker, and determine whether the opening and closing state of the circuit breaker is normal based on the electric field strength criterion and the real-time electric field signal.

2. The circuit breaker opening and closing state change monitoring method according to claim 1, characterized in that: The step S20 comprises: Obtain real-time vibration signals of the circuit breaker beam position, A phase position, B phase position and C phase position; The state characteristic quantities of the real-time vibration signals of the circuit breaker crossbeam position, A phase position, B phase position and C phase position are extracted respectively; All state feature quantities are compared for consistency with historical vibration signals in the comprehensive signal library through a correlation test method to determine whether the real-time vibration signal corresponding to the state feature quantity belongs to one of a noise signal, a normal vibration signal and an abnormal vibration signal.

3. The circuit breaker opening and closing state change monitoring method according to claim 2, characterized in that: include: Performing a first correlation test on the state feature quantity and the state feature quantity of the clutter signal to obtain a first correlation degree, and when the first correlation degree is greater than a correlation threshold, determining that the real-time vibration signal corresponding to the state feature quantity belongs to the clutter signal; When the correlation is less than the correlation threshold, a second correlation test is performed on the state feature quantity and the state feature quantity of the normal vibration signal to obtain a second correlation; when the second correlation is greater than the correlation threshold, it is determined that the real-time vibration signal corresponding to the state feature quantity belongs to a normal vibration signal, and it is determined that the current circuit breaker opening and closing state is normal; When the second correlation is less than the correlation threshold, it is determined that the current circuit breaker opening and closing state is abnormal.

4. The circuit breaker opening and closing state change monitoring method according to claim 3, characterized in that: include: Correlation checks are performed on the state characteristic quantity and the vibration signals under various types of faults to determine the fault type corresponding to the real-time vibration signal.

5. The circuit breaker opening and closing state change monitoring method according to claim 3, characterized in that: include: When the real-time vibration signal corresponding to the state characteristic quantity belongs to a normal vibration signal, the data parameter of the real-time vibration signal is extracted, and when the data parameter is greater than a warning threshold, an alarm is issued.

6. The circuit breaker opening and closing state change monitoring method according to claim 2, characterized in that: include: Perform zero drift adjustment on the acquired real-time vibration signal.

7. The circuit breaker opening and closing state change monitoring method according to claim 1, characterized in that: The step S30 comprises: Acquire the real-time electric field signal of the circuit breaker at the end of the three-phase porcelain insulation of the circuit breaker and the real-time electric field signal of the current transformer at the end of the three-phase porcelain insulation of the connected current transformer; Establishing a circuit breaker electric field strength graph according to the circuit breaker real-time electric field signal, and establishing a current transformer electric field strength graph according to the current transformer real-time electric field signal; According to the electric field strength criterion, the circuit breaker electric field strength graph and the current transformer electric field strength graph, it is determined whether the circuit breaker opening and closing states are normal and whether the circuit breaker and the current transformer are damaged in insulation.

8. The method for monitoring the change of the circuit breaker opening and closing state according to claim 7, characterized in that: The electric field strength criterion includes: When the circuit breaker electric field strength graph and the current transformer electric field strength graph are both symmetrically distributed in the center, the circuit breaker is in a closed state; When the electric field strength graph of the circuit breaker and the electric field strength graph of the current transformer are both in a straight line distribution, the circuit breaker is in an open state and the connected current transformer is in a power-off state; When the circuit breaker electric field strength graph and the current transformer electric field strength graph are both symmetrically distributed in the center and the maximum value of the circuit breaker electric field strength is lower than the maximum value of the current transformer electric field strength, the circuit breaker is in an open state and the connected current transformer is in a energized state; When the electric field strength graph of the circuit breaker and the electric field strength graph of the current transformer are both in an irregular state, the circuit breaker or the connected current transformer is in an insulation damaged state.

9. A circuit breaker opening and closing state change monitoring system, characterized in that: The method for monitoring the change of the circuit breaker opening and closing state according to any one of claims 1 to 8 comprises: Vibration sensor, used to obtain real-time vibration signals generated during the opening and closing process of the circuit breaker; Electric field sensor, used to obtain real-time electric field signals during the opening and closing process of the circuit breaker; The processing module is used to determine whether the opening and closing state of the circuit breaker is normal by comparing the real-time vibration signal with the historical vibration signal in the comprehensive signal library for consistency, and determine whether the opening and closing state of the circuit breaker is normal based on the electric field strength criterion and the real-time electric field signal.

10. The circuit breaker opening and closing state change monitoring system according to claim 9, characterized in that: It also includes an alarm device, which is communicatively connected to the processing module and is used for giving an alarm under the control of the processing module.

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