A method and apparatus for monitoring the insulation condition of a capacitor bank

Abstract

This invention discloses a method and apparatus for monitoring the insulation status of a capacitor bank. The method includes acquiring the circuit structure of the capacitor bank to be monitored, performing three-phase circuit modeling according to the circuit structure, generating a capacitor bank model, simulating the insulation status using the capacitor bank model, generating a monitoring current ratio, and when receiving scheduling data sent by an external terminal, determining the corresponding equivalent capacitance ratio based on the monitoring current ratio and the scheduling data. Based on the equivalent capacitance ratio and a preset state threshold range, it is determined whether the insulation status of the capacitor bank to be monitored is abnormal, thereby effectively reducing monitoring costs while ensuring the accuracy of insulation status monitoring.

Description

Technical Field

[0001] This invention relates to the field of condition monitoring technology, and in particular to a method and apparatus for monitoring the insulation condition of capacitor banks. Background Technology

[0002] With the construction and development of smart grids, grid voltage regulation is becoming increasingly important. As the most important voltage regulation equipment, the health status of capacitor banks directly affects their availability and indirectly affects the grid voltage qualification rate.

[0003] Therefore, it is necessary to monitor the insulation status of capacitor banks in real time, realize automatic identification, intelligent diagnosis and early warning of equipment defects, achieve the analytical and diagnostic capabilities of expert consultation, provide a basis and support for intelligent operation and maintenance decisions, and has important engineering application prospects.

[0004] However, there are very few methods for monitoring the insulation status of capacitor banks. The insulation status of capacitor banks is usually monitored by installing a large number of monitoring devices, which is costly. Summary of the Invention

[0005] This invention provides a method and apparatus for monitoring the insulation status of capacitor banks, which solves the technical problem that existing methods for monitoring the insulation status of capacitor banks involve installing a large number of monitoring devices, resulting in high monitoring costs.

[0006] This invention provides a method for monitoring the insulation status of a capacitor bank, comprising:

[0007] Obtain the circuit structure of the capacitor bank to be monitored, and perform three-phase circuit modeling according to the circuit structure to generate a capacitor bank model.

[0008] The insulation state was simulated using the capacitor bank model to generate the monitoring current ratio.

[0009] When scheduling data is received from an external terminal, the corresponding equivalent capacitance ratio is determined based on the monitored current ratio and the scheduling data.

[0010] Based on the equivalent capacitance ratio and the preset state threshold range, determine whether the insulation state of the capacitor bank to be monitored is abnormal.

[0011] Optionally, the step of using the capacitor bank model to simulate the insulation state and generate the monitoring current ratio includes:

[0012] By analyzing the capacitor bank model, multiple electrical parameters and the initial equivalent capacitance corresponding to each phase are obtained;

[0013] In response to the input equivalent capacitance change factor, the changed current of the target phase corresponding to the equivalent capacitance change factor is calculated in combination with the initial equivalent capacitance.

[0014] The ratio of the monitoring current between the target phase and the adjacent phase is determined by combining the modified current with the equivalent capacitance change ratio.

[0015] Optionally, the step of determining the corresponding equivalent capacitance ratio based on the monitored current ratio and the scheduling data when receiving scheduling data from an external terminal includes:

[0016] When scheduling data is received from an external terminal, the source phase and phase current value of the scheduling data are determined.

[0017] Calculate the equivalent capacitance ratio corresponding to the source phase based on the phase current value and the corresponding monitoring current ratio.

[0018] Optionally, the step of determining whether the insulation state of the capacitor bank to be monitored is abnormal according to the equivalent capacitance ratio and the preset state threshold range includes:

[0019] Determine whether the equivalent capacitance ratio is within a preset state threshold range;

[0020] If so, the insulation status of the capacitor bank to be monitored is determined to be normal;

[0021] If not, the insulation condition of the capacitor bank to be monitored is determined to be abnormal.

[0022] Optionally, the state threshold range includes two extreme values ​​at the endpoints, and the method further includes:

[0023] If the equivalent capacitance ratio is not within the state threshold range, the ratio difference between the equivalent capacitance ratio and each endpoint extreme value is calculated according to a preset time interval.

[0024] If any of the ratio differences is greater than the preset adjustment threshold, then the process jumps to the step of obtaining the circuit structure of the capacitor bank to be monitored, and performing three-phase circuit modeling according to the circuit structure to generate the capacitor bank model.

[0025] If the ratio difference is less than or equal to a preset adjustment threshold, the insulation state of the capacitor bank to be monitored is determined to be abnormal.

[0026] The present invention also provides an insulation condition monitoring device for capacitor banks, comprising:

[0027] The information acquisition module is used to acquire the circuit structure of the capacitor bank to be monitored, and to perform three-phase circuit modeling according to the circuit structure to generate a capacitor bank model.

[0028] The state simulation module is used to simulate the insulation state using the capacitor bank model and generate the monitoring current ratio.

[0029] The equivalent capacitance ratio determination module is used to determine the corresponding equivalent capacitance ratio based on the monitored current ratio and the scheduling data when receiving scheduling data sent by an external terminal.

[0030] The insulation status judgment module is used to determine whether the insulation status of the capacitor bank to be monitored is abnormal according to the equivalent capacitance ratio and the preset status threshold range.

[0031] Optionally, the state simulation module is specifically used for:

[0032] By analyzing the capacitor bank model, multiple electrical parameters and the initial equivalent capacitance corresponding to each phase are obtained;

[0033] In response to the input equivalent capacitance change factor, the changed current of the target phase corresponding to the equivalent capacitance change factor is calculated in combination with the initial equivalent capacitance.

[0034] The ratio of the monitoring current between the target phase and the adjacent phase is determined by combining the modified current with the equivalent capacitance change ratio.

[0035] Optionally, the equivalent capacitance ratio determination module is specifically used for:

[0036] When scheduling data is received from an external terminal, the source phase and phase current value of the scheduling data are determined.

[0037] Calculate the equivalent capacitance ratio corresponding to the source phase based on the phase current value and the corresponding monitoring current ratio.

[0038] Optionally, the insulation state determination module is specifically used for:

[0039] Determine whether the equivalent capacitance ratio is within a preset state threshold range;

[0040] If so, the insulation status of the capacitor bank to be monitored is determined to be normal;

[0041] If not, the insulation condition of the capacitor bank to be monitored is determined to be abnormal.

[0042] Optionally, the state threshold range includes two extreme values ​​at the endpoints, and the device further includes:

[0043] The multiplier difference calculation module is used to calculate the multiplier difference between the equivalent capacitance multiplier and each of the endpoint extreme values ​​according to a preset time interval if the equivalent capacitance multiplier is not within the state threshold range.

[0044] The jump module is used to jump to the step of obtaining the circuit structure of the capacitor bank to be monitored and performing three-phase circuit modeling according to the circuit structure to generate a capacitor bank model if any of the ratio differences is greater than a preset adjustment threshold.

[0045] The anomaly detection module is used to determine that the insulation state of the capacitor bank to be monitored is abnormal if the ratio difference is less than or equal to a preset adjustment threshold.

[0046] As can be seen from the above technical solutions, the present invention has the following advantages:

[0047] This invention obtains the circuit structure of the capacitor bank to be monitored, performs three-phase circuit modeling according to the circuit structure, generates a capacitor bank model, simulates the insulation state using the capacitor bank model, and generates a monitoring current ratio. When scheduling data sent by an external terminal is received, the corresponding equivalent capacitance ratio is determined based on the monitoring current ratio and the scheduling data. According to the equivalent capacitance ratio and a preset state threshold range, it is determined whether the insulation state of the capacitor bank to be monitored is abnormal, thereby effectively reducing monitoring costs while ensuring the accuracy of insulation state monitoring. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a flowchart of the steps of a capacitor bank insulation status monitoring method provided in Embodiment 1 of the present invention;

[0050] Figure 2 This is a schematic diagram of a capacitor bank model according to an embodiment of the present invention;

[0051] Figure 3 This is a flowchart illustrating the steps of a capacitor bank insulation status monitoring method provided in Embodiment 2 of the present invention.

[0052] Figure 4 This is a schematic diagram of a three-phase potential according to an embodiment of the present invention;

[0053] Figure 5 This is a structural block diagram of an insulation condition monitoring device for a capacitor bank provided in an embodiment of the present invention. Detailed Implementation

[0054] This invention provides a method and apparatus for monitoring the insulation status of capacitor banks, which addresses the technical problem that existing methods for monitoring the insulation status of capacitor banks involve installing a large number of monitoring devices, resulting in high monitoring costs.

[0055] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0056] Please see Figure 1 , Figure 1 This is a flowchart illustrating the steps of a capacitor bank insulation status monitoring method provided in Embodiment 1 of the present invention.

[0057] This invention provides a method for monitoring the insulation status of a capacitor bank, comprising:

[0058] Step 101: Obtain the circuit structure of the capacitor bank to be monitored, and perform three-phase circuit modeling according to the circuit structure to generate a capacitor bank model.

[0059] A capacitor bank under monitoring refers to a working group composed of multiple capacitors, which can be connected in series or in parallel. In series connection, the withstand voltage is the sum of the two capacitors, and the capacitance is the reciprocal of the sum of the two. In parallel connection, the withstand voltage is the lowest of the two capacitors, and the capacitance is the sum of the two. Simply put, in series connection, as the withstand voltage increases, the capacitance decreases. In parallel connection, the withstand voltage remains unchanged, but the capacitance increases.

[0060] Circuit structure refers to the circuit structure necessary for the capacitor bank to perform its function, such as the circuit structure of a capacitor bank connected in series with a reactor.

[0061] In this embodiment of the invention, the circuit structure of the capacitor bank to be monitored can be obtained by means of lidar point cloud scanning or image vision, and at the same time, a three-phase circuit model is performed on it according to the circuit structure using circuit theory analysis technology to generate a capacitor bank model.

[0062] like Figure 2 As shown, Figure 2 The capacitor bank model is shown, generated by modeling a circuit structure in which the capacitor bank and the reactor are connected in series.

[0063] The rated reactance is x, the capacitance is C, the capacitive reactance of the capacitor is 1 / ωC, then the reactance of the reactor is x / ωC, the impedance of the two in series is (1-x) / ωC, and the three-phase equivalent capacitance is Ca=Cb=Cc=C / (1-x).

[0064] Step 102: Simulate the insulation state using a capacitor bank model to generate the monitoring current ratio;

[0065] After creating the capacitor bank model, you can simulate its insulation state by increasing or decreasing the capacitance by a factor of k to determine the monitoring current ratio corresponding to the circuit structure under different factors.

[0066] It should be noted that, for three-phase current, the monitored current ratio is mainly the current ratio after the capacitance value of a single phase changes. For example, in an ABC three-phase circuit, the current ratio between phases A and B after the capacitance value of phase A changes by a factor of k.

[0067] Step 103: When the scheduling data sent by the external terminal is received, the corresponding equivalent capacitance ratio is determined according to the monitoring current ratio and the scheduling data.

[0068] In power grid systems, there are usually various ways to monitor power parameters such as current and voltage in real time for capacitor banks or the entire circuit structure. Data acquisition costs can be reduced by data reuse. This method does not require additional monitoring devices. Instead, after simulating the insulation state of the capacitor bank model, it monitors the scheduling data transmitted by other external terminals in real time. When it receives scheduling data detected by external terminals such as upstream current detection devices or other software, it calculates the corresponding equivalent capacitance ratio based on the matching relationship between the scheduling data and the monitored current ratio.

[0069] The scheduling data consists of the current values ​​of each phase in the three-phase circuit of the capacitor bank.

[0070] Step 104: Determine whether the insulation status of the capacitor bank to be monitored is abnormal according to the equivalent capacitance ratio and the preset state threshold range.

[0071] After determining the equivalent capacitance ratio, it can be further determined whether the equivalent capacitance ratio is within the preset state threshold range. This can be used as the basis for judging the insulation state of the capacitor bank to be monitored, and to determine whether the insulation state of the capacitor bank to be monitored is abnormal.

[0072] In this embodiment of the invention, the circuit structure of the capacitor bank to be monitored is obtained, and a three-phase circuit model is performed according to the circuit structure to generate a capacitor bank model. The capacitor bank model is used to simulate the insulation state and generate a monitoring current ratio. When the scheduling data sent by the external terminal is received, the corresponding equivalent capacitance ratio is determined according to the monitoring current ratio and the scheduling data. According to the equivalent capacitance ratio and the preset state threshold range, it is determined whether the insulation state of the capacitor bank to be monitored is abnormal, thereby effectively reducing the monitoring cost while ensuring the monitoring accuracy of the insulation state.

[0073] Please see Figure 3 , Figure 3 This is a flowchart illustrating the steps of a capacitor bank insulation status monitoring method provided in Embodiment 2 of the present invention.

[0074] This invention provides a method for monitoring the insulation status of a capacitor bank, comprising:

[0075] Step 201: Obtain the circuit structure of the capacitor bank to be monitored, and perform three-phase circuit modeling according to the circuit structure to generate a capacitor bank model.

[0076] In this embodiment of the invention, the specific implementation process of step 201 is similar to that of step 101, and will not be repeated here.

[0077] Step 202: Analyze the capacitor bank model to obtain multiple electrical parameters and the initial equivalent capacitance corresponding to each phase;

[0078] In embodiments of the present invention, such as Figure 2 The capacitor bank model shown is analyzed to determine the types of components it contains. The electrical parameters corresponding to each component are obtained, such as rated reactance x, capacitance C, and capacitive reactance 1 / ωC. Therefore, the reactance of the reactor is x / ωC, and the impedance of the two in series is (1-x) / ωC. The initial equivalent capacitance C corresponding to each of the three phases is also obtained. a =C b =C c =C / (1-x).

[0079] It should be noted that, according to KCL theorem, we know that:

[0080]

[0081] in, Let be the voltage vector of phase a. Let n be the voltage vector at point n. Let be the voltage vector of phase b. Let be the voltage vector of phase c.

[0082] Step 203: In response to the input equivalent capacitance change ratio, calculate the changed current of the target phase corresponding to the equivalent capacitance change ratio based on the initial equivalent capacitance.

[0083] In this embodiment of the invention, in response to the equivalent capacitance change ratio input by an external terminal or user, the changed current of the target phase corresponding to the equivalent capacitance change ratio can be calculated in combination with the initial equivalent capacitance.

[0084] For example, if phase a is the target phase and the equivalent capacitance change factor is k, then before the change, there exists C. a =C b =C c .

[0085] The calculation process can be as follows:

[0086]

[0087] ∵

[0088] ∴ And I a =U a ωC a

[0089] ∴

[0090] Among them, I a The current value of phase a before the capacitor is changed by a factor of k is the current value before the change. Let U be the current vector of phase a before the capacitance is changed by a factor of k. n Let U be the voltage value at point n before the capacitor is changed by a factor of k. a Let be the voltage value of phase a before the capacitance is changed by a factor of k. Let C' be the changed current vector of phase a after the capacitance is changed by a factor of k. a The capacitance value after changing phase a by a factor of k.

[0091] Step 204: Using the changed current combined with the equivalent capacitance change ratio, determine the monitoring current ratio between the target phase and the adjacent phase;

[0092] Please see Figure 4 , Figure 4 This is a schematic diagram of three-phase potential.

[0093] In this embodiment, the ratio of the monitoring current between the target phase and the adjacent phase can be determined by combining the changed current with the equivalent capacitance change ratio, as follows:

[0094] U bn 2 =U a 2 +Un 2 -2U a ×U n ×cos120°

[0095]

[0096]

[0097]

[0098] Among them, I' b Let I' be the changed current value of phase b after the capacitor is changed by a factor of k. a U is the changed current value of phase a after the capacitance is changed by a factor of k. bn This represents the voltage value between phase b and point n.

[0099] Therefore, when the equivalent capacitance change factor of phase a is k, the monitoring current ratio between phases a and b is:

[0100]

[0101] It should be noted that the above is only an example of the monitoring current ratio between phases ab. The specific calculation process for the monitoring current ratio between phases bc or ac can be found in the above calculation process, and will not be repeated in the embodiments of the present invention.

[0102] Step 205: When the scheduling data sent by the external terminal is received, the corresponding equivalent capacitance ratio is determined based on the monitoring current ratio and the scheduling data.

[0103] Optionally, step 205 may include the following sub-steps:

[0104] When scheduling data is received from an external terminal, the source phase and phase current value of the scheduling data are determined.

[0105] Calculate the equivalent capacitance ratio corresponding to the source phase based on the phase current value and the corresponding monitoring current ratio.

[0106] In this embodiment of the invention, when scheduling data sent by an external terminal is received, the source phase and the corresponding phase current value corresponding to the location data can be located, that is, it can be determined whether the source phase is phase a, phase b or phase c, and the corresponding phase current value can be determined at the same time.

[0107] Substitute the phase current value into the above monitoring current ratio to calculate the equivalent capacitance ratio k corresponding to the source phase.

[0108] It should be noted that the dispatching system stores capacitor current data in E-format files, establishes an SFTP service to provide data access to the online monitoring system, and the online monitoring system parses the received E-format files and writes them to its database. The specific description of the E-format file is as follows:

[0109] The Dispatch Automation System (EMS) periodically queries information from substation monitoring points at fixed time intervals. This information includes substation site information, measurement point information, measurement values, time points, and the latest current and voltage data from the main grid. The automation department acquires telemetry data in TXT file format. The capacitor monitoring system is deployed at the testing institute and interacts directly with the dispatch department via an SFTP data interface, transmitting data in text file format. The telemetry data is stored in TXT file format, with the following five columns: Substation Name + Measurement Name + Measurement Point ID + Measurement Value + Data Time.

[0110] For example:

[0111] Jiangnan 10kV #3A Capacitor 53AC Switch ME-805 0 2022 / 3 / 21 0:00:08

[0112] The parsed information indicates that the switch status of the 10kV#3A capacitor 53AC switch (monitoring point id: ME-805) at Jiangnan Station was 0 at 0:00:08 on 2022 / 3 / 21.

[0113] The current in phase B of the 10kV #2B capacitor at Sanjiang is ME-716741.085. (2018 / 1 / 1 0:00:03)

[0114] The extracted information indicates that the B-phase current of the 10kV#2B capacitor at Sanjiang Station (monitoring point id: ME-716741) is 0.085 at 0:00:03 on 2018 / 1 / 1.

[0115] Step 206: Determine whether the insulation status of the capacitor bank to be monitored is abnormal according to the equivalent capacitance ratio and the preset state threshold range.

[0116] Optionally, step 206 may include the following sub-steps:

[0117] Determine whether the equivalent capacitance ratio is within the state threshold range;

[0118] If so, the insulation condition of the capacitor bank to be monitored is determined to be normal;

[0119] If not, the insulation condition of the capacitor bank to be monitored is determined to be abnormal.

[0120] In this embodiment of the invention, it is determined whether the equivalent capacitance ratio is within the state threshold range. If it is, it indicates that the capacitance value of the capacitor bank under monitoring is still within the acceptable range, and the insulation state of the capacitor bank under monitoring can be determined to be normal. If it is not, it indicates that the capacitance value of the capacitor bank under monitoring is not within the acceptable range, and the capacitor bank under monitoring has experienced a change exceeding the range, and the insulation state of the capacitor bank under monitoring can be determined to be abnormal.

[0121] In practical implementation, the acceptable range of capacitance value is ±5%. Assuming reactance x = 5%, according to Ca = C / (1-x), the acceptable range of k is 95.25% to 104.75%, and the corresponding current ratio is 0.9755 to 1.0231.

[0122] Furthermore, the state threshold range includes two extreme values ​​at the endpoints, and the method also includes:

[0123] If the equivalent capacitance ratio is not within the state threshold range, the ratio difference between the equivalent capacitance ratio and the extreme values ​​of each endpoint is calculated according to the preset time interval.

[0124] If any ratio difference is greater than the preset adjustment threshold, the process will jump to the steps of obtaining the circuit structure of the capacitor bank to be monitored, and performing three-phase circuit modeling according to the circuit structure to generate the capacitor bank model.

[0125] If the ratio difference is less than or equal to the preset adjustment threshold, the insulation status of the capacitor bank to be monitored is determined to be abnormal.

[0126] In another example of the present invention, the state threshold range includes two extreme values, namely the maximum value and the minimum value. When it is determined that the equivalent capacitance ratio is not within the state threshold range, it indicates that the capacitor bank to be monitored may have an abnormal insulation state.

[0127] However, during the long-term operation of the capacitor bank, since this embodiment of the invention does not require a monitoring device, it is impossible to monitor the circuit structure of the capacitor bank under monitoring in real time. In this case, the circuit structure may change, and the equivalent capacitance ratio may actually meet the requirements, but due to the inability to obtain real-time information about the circuit structure, a judgment deviation may occur. In this situation, the difference between the equivalent capacitance ratio and the extreme values ​​at each endpoint can be calculated at preset time intervals. If any difference is greater than a preset adjustment threshold, steps 201-206 are executed to model and judge the capacitor bank under monitoring again. If the difference is less than or equal to the preset adjustment threshold, the insulation state of the capacitor bank under monitoring is determined to be abnormal.

[0128] In this embodiment of the invention, the circuit structure of the capacitor bank to be monitored is obtained, and a three-phase circuit model is performed according to the circuit structure to generate a capacitor bank model. The capacitor bank model is used to simulate the insulation state and generate a monitoring current ratio. When the scheduling data sent by the external terminal is received, the corresponding equivalent capacitance ratio is determined according to the monitoring current ratio and the scheduling data. According to the equivalent capacitance ratio and the preset state threshold range, it is determined whether the insulation state of the capacitor bank to be monitored is abnormal, thereby effectively reducing the monitoring cost while ensuring the monitoring accuracy of the insulation state.

[0129] Please see Figure 5 , Figure 5 A structural block diagram of an insulation condition monitoring device for a capacitor bank provided in an embodiment of the present invention is shown.

[0130] The present invention also provides an insulation condition monitoring device for capacitor banks, comprising:

[0131] The information acquisition module 501 is used to acquire the circuit structure of the capacitor bank to be monitored, and to perform three-phase circuit modeling according to the circuit structure to generate a capacitor bank model.

[0132] The state simulation module 502 is used to simulate the insulation state using a capacitor bank model and generate a monitoring current ratio.

[0133] The equivalent capacitance ratio determination module 503 is used to determine the corresponding equivalent capacitance ratio based on the monitored current ratio and the scheduling data when receiving scheduling data sent by an external terminal.

[0134] The insulation status judgment module 504 is used to determine whether the insulation status of the capacitor bank to be monitored is abnormal according to the equivalent capacitance ratio and the preset status threshold range.

[0135] Optionally, the state simulation module 502 is specifically used for:

[0136] The capacitor bank model is analyzed to obtain multiple electrical parameters and the initial equivalent capacitance corresponding to each phase.

[0137] The equivalent capacitance change factor is responded to, and the changed current of the target phase corresponding to the equivalent capacitance change factor is calculated in combination with the initial equivalent capacitance.

[0138] The ratio of the monitoring current between the target phase and the adjacent phase is determined by combining the changed current with the equivalent capacitance change ratio.

[0139] Optionally, the equivalent capacitance ratio determination module 503 is specifically used for:

[0140] When scheduling data is received from an external terminal, the source phase and phase current value of the scheduling data are determined.

[0141] Calculate the equivalent capacitance ratio corresponding to the source phase based on the phase current value and the corresponding monitoring current ratio.

[0142] Optionally, the insulation condition determination module 504 is specifically used for:

[0143] Determine whether the equivalent capacitance ratio is within the preset state threshold range;

[0144] If so, the insulation condition of the capacitor bank to be monitored is determined to be normal;

[0145] If not, the insulation condition of the capacitor bank to be monitored is determined to be abnormal.

[0146] Optionally, the state threshold range includes two extreme values ​​at the endpoints, and the device further includes:

[0147] The ratio difference calculation module is used to calculate the ratio difference between the equivalent capacitance ratio and the extreme values ​​of each endpoint according to a preset time interval if the equivalent capacitance ratio is not within the state threshold range.

[0148] The jump module is used to jump to the steps of obtaining the circuit structure of the capacitor bank to be monitored and performing three-phase circuit modeling according to the circuit structure to generate the capacitor bank model if any ratio difference is greater than the preset adjustment threshold.

[0149] The anomaly detection module is used to determine that the insulation status of the capacitor bank under monitoring is abnormal if the ratio difference is less than or equal to a preset adjustment threshold.

[0150] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described device and module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0151] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0152] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0153] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0154] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for monitoring the insulation status of a capacitor bank, characterized in that, include: Obtain the circuit structure of the capacitor bank to be monitored, and perform three-phase circuit modeling according to the circuit structure to generate a capacitor bank model. The insulation state was simulated using the capacitor bank model to generate the monitoring current ratio. When scheduling data is received from an external terminal, the corresponding equivalent capacitance ratio is determined based on the monitored current ratio and the scheduling data. Based on the equivalent capacitance ratio and the preset state threshold range, determine whether the insulation state of the capacitor bank to be monitored is abnormal.

2. The method according to claim 1, characterized in that, The step of simulating the insulation state using the capacitor bank model and generating the monitoring current ratio includes: By analyzing the capacitor bank model, multiple electrical parameters and the initial equivalent capacitance corresponding to each phase are obtained; In response to the input equivalent capacitance change factor, the changed current of the target phase corresponding to the equivalent capacitance change factor is calculated in combination with the initial equivalent capacitance. The ratio of the monitoring current between the target phase and the adjacent phase is determined by combining the modified current with the equivalent capacitance change ratio.

3. The method according to claim 1, characterized in that, The step of determining the corresponding equivalent capacitance ratio based on the monitored current ratio and the scheduling data when receiving scheduling data from an external terminal includes: When scheduling data is received from an external terminal, the source phase and phase current value of the scheduling data are determined. Calculate the equivalent capacitance ratio corresponding to the source phase based on the phase current value and the corresponding monitoring current ratio.

4. The method according to claim 1, characterized in that, The step of determining whether the insulation state of the capacitor bank to be monitored is abnormal according to the equivalent capacitance ratio and the preset state threshold range includes: Determine whether the equivalent capacitance ratio is within a preset state threshold range; If so, the insulation status of the capacitor bank to be monitored is determined to be normal; If not, the insulation condition of the capacitor bank to be monitored is determined to be abnormal.

5. The method according to any one of claims 1-4, characterized in that, The state threshold range includes two extreme values ​​at the endpoints, and the method further includes: If the equivalent capacitance ratio is not within the state threshold range, the ratio difference between the equivalent capacitance ratio and each endpoint extreme value is calculated according to a preset time interval. If any of the ratio differences is greater than the preset adjustment threshold, then the process jumps to the step of obtaining the circuit structure of the capacitor bank to be monitored, and performing three-phase circuit modeling according to the circuit structure to generate the capacitor bank model. If the ratio difference is less than or equal to a preset adjustment threshold, the insulation state of the capacitor bank to be monitored is determined to be abnormal.

6. A device for monitoring the insulation status of a capacitor bank, characterized in that, include: The information acquisition module is used to acquire the circuit structure of the capacitor bank to be monitored, and to perform three-phase circuit modeling according to the circuit structure to generate a capacitor bank model. The state simulation module is used to simulate the insulation state using the capacitor bank model and generate the monitoring current ratio. The equivalent capacitance ratio determination module is used to determine the corresponding equivalent capacitance ratio based on the monitored current ratio and the scheduling data when receiving scheduling data sent by an external terminal. The insulation status judgment module is used to determine whether the insulation status of the capacitor bank to be monitored is abnormal according to the equivalent capacitance ratio and the preset status threshold range.

7. The apparatus according to claim 6, characterized in that, The state simulation module is specifically used for: By analyzing the capacitor bank model, multiple electrical parameters and the initial equivalent capacitance corresponding to each phase are obtained; In response to the input equivalent capacitance change factor, the changed current of the target phase corresponding to the equivalent capacitance change factor is calculated in combination with the initial equivalent capacitance. The ratio of the monitoring current between the target phase and the adjacent phase is determined by combining the modified current with the equivalent capacitance change ratio.

8. The apparatus according to claim 6, characterized in that, The equivalent capacitance ratio determination module is specifically used for: When scheduling data is received from an external terminal, the source phase and phase current value of the scheduling data are determined. Calculate the equivalent capacitance ratio corresponding to the source phase based on the phase current value and the corresponding monitoring current ratio.

9. The apparatus according to claim 6, characterized in that, The insulation state determination module is specifically used for: Determine whether the equivalent capacitance ratio is within a preset state threshold range; If so, the insulation status of the capacitor bank to be monitored is determined to be normal; If not, the insulation condition of the capacitor bank to be monitored is determined to be abnormal.

10. The apparatus according to any one of claims 6-9, characterized in that, The state threshold range includes two extreme values ​​at the endpoints, and the device further includes: The multiplier difference calculation module is used to calculate the multiplier difference between the equivalent capacitance multiplier and each of the endpoint extreme values ​​according to a preset time interval if the equivalent capacitance multiplier is not within the state threshold range. The jump module is used to jump to the step of obtaining the circuit structure of the capacitor bank to be monitored and performing three-phase circuit modeling according to the circuit structure to generate a capacitor bank model if any of the ratio differences is greater than a preset adjustment threshold. The anomaly detection module is used to determine that the insulation state of the capacitor bank to be monitored is abnormal if the ratio difference is less than or equal to a preset adjustment threshold.

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