Information processing device and information processing method

Abstract

To accurately evaluate the insulation degradation state of a load system with higher accuracy than conventional methods.SOLUTION: An information processing device (10) is configured to: evaluate the insulation degradation state of a load system (UN) including a load (LD) and a three-phase distribution line (HL) for supplying three-phase AC power to the load (LD); acquire a detected value of a zero-phase current from a ZCT (80) for detecting the zero-phase current flowing through the three-phase distribution line (HL); calculate, as a representative value of the plurality of detected values during a predetermined period, either (i) the average value of the plurality of detected values during the predetermined period or (ii) the median value of the plurality of detected values during the predetermined period; extract the maximum value from among the plurality of detected values during the predetermined period; calculate the value obtained by subtracting the representative value during the predetermined period from the maximum value as an evaluation target value corresponding to the plurality of detected values during the predetermined period; and evaluate the insulation degradation state on the basis of the evaluation target value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] One aspect of the present invention relates to an information processing device that evaluates the state of insulation deterioration of a load system. [Background technology]

[0002] Various techniques have been proposed for monitoring abnormalities in electrical equipment, etc. For example, Patent Document 1 listed below discloses a method for detecting a zero-phase current (referred to as a leakage current in Patent Document 1) in a power distribution line and evaluating the state of insulation deterioration of a load system based on the zero-phase current. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-243787 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of one aspect of the present invention is to evaluate the state of insulation deterioration of a load system with higher accuracy than conventional methods. [Means for solving the problem]

[0005] An information processing device according to one embodiment of the present invention is an information processing device that evaluates the insulation deterioration state of a load system including a load and a three-phase distribution line that supplies three-phase AC power to the load, and obtains a detection value of the zero-phase current from a ZCT (Zero Current Transformer) that detects the zero-phase current flowing in the three-phase distribution line, calculates (i) the average value of the multiple detection values ​​in the specified period, or (ii) the median value of the multiple detection values ​​in the specified period as a representative value of the multiple detection values ​​in the specified period, extracts the maximum value from the multiple detection values ​​in the specified period, calculates a value obtained by subtracting the representative value for the specified period from the maximum value for the specified period, and calculates the value as an evaluation target value corresponding to the multiple detection values ​​in the specified period, and evaluates the insulation deterioration state based on the evaluation target value.

[0006] An information processing method according to one aspect of the present invention is an information processing method for evaluating an insulation deterioration state of a load system including a load and a three-phase distribution line that supplies three-phase AC power to the load, the information processing method including the steps of: acquiring a detection value of the zero-phase current from a ZCT (Zero Current Transformer) that detects the zero-phase current flowing in the three-phase distribution line; calculating (i) an average value of the plurality of detection values ​​in the predetermined period or (ii) a median value of the plurality of detection values ​​in the predetermined period as a representative value of the plurality of detection values ​​in the predetermined period; extracting a maximum value from the plurality of detection values ​​in the predetermined period; calculating a value obtained by subtracting the representative value for the predetermined period from the maximum value for the predetermined period as an evaluation target value corresponding to the plurality of detection values ​​in the predetermined period; and evaluating the insulation deterioration state based on the evaluation target value. [Effects of the Invention]

[0007] According to one aspect of the present invention, the state of insulation deterioration of a load system can be evaluated with higher accuracy than conventional methods. [Brief explanation of the drawings]

[0008] [Figure 1]1 shows an example of the configuration of an evaluation system and its peripherals in the first embodiment. [Figure 2] An example of the time transition of the average current value in a healthy case is shown. [Figure 3] An example of the time transition of the maximum current value in a healthy case is shown below. [Figure 4] An example of the time transition of the differential current value in a healthy case is shown. [Figure 5] An example of the time transition of the average current value in an accident case is shown. [Figure 6] An example of the time progression of maximum current value in an accident case is shown below. [Figure 7] 10 shows an example of the time transition of the differential current value in an accident case. [Figure 8] 10 shows an example of the time transition of the first cumulative count in a healthy case. [Figure 9] 10 shows an example of the time transition of the second cumulative count in a healthy case. [Figure 10] An example of the time transition of the third cumulative count in a healthy case is shown. [Figure 11] 10 shows an example of the time transition of the first cumulative number in an accident case. [Figure 12] 10 shows an example of the time transition of the second cumulative number in an accident case. [Figure 13] An example of the change over time in the third cumulative number of accident cases is shown. [Figure 14] An example of the time progression of the risk level in a healthy case is shown below. [Figure 15] An example of the time progression of risk levels in an accident case is shown below. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Embodiment 1] Embodiment 1 will be described below. For convenience of explanation, components having the same functions as those described in Embodiment 1 will be denoted by the same reference numerals in the following embodiments, and their description will not be repeated. For simplicity, descriptions of well-known technical matters will be omitted as appropriate. Unless otherwise specified, the components and numerical values ​​described in this disclosure are merely examples. Therefore, for example, unless otherwise specified, the positional and connection relationships of the components are not limited to the examples in the figures.

[0010] FIG. 1 illustrates an example of an evaluation system 1 and its peripheral configuration in embodiment 1. The evaluation system 1 includes an information processing device 10 and a ZCT (Zero Current Transformer) 80. In the example of FIG. 1, the information processing device 10 is located inside electrical equipment EE. In FIG. 1, a power distribution facility is exemplified as the electrical equipment EE. In the example of FIG. 1, a load LD is located outside the electrical equipment EE.

[0011] In the example of Fig. 1, a three-phase AC power system PL is located upstream of the electrical equipment EE. The electrical equipment EE in Fig. 1 has a transformer TR. The primary side of the transformer TR is connected to the power system PL, and the secondary side of the transformer TR is connected to the power distribution system of the electrical equipment EE.

[0012] 1 transforms the high voltage (e.g., 6000 V) of the power system PL into a lower voltage (e.g., 200 V) suitable for the load LD. In this way, the transformer TR supplies the low voltage to the load LD.

[0013] 1, N loads LD are illustrated. N may be any natural number. In the first embodiment, a case where there are a plurality of loads LD, that is, N is 2 or more, is illustrated.

[0014] In this specification, when distinguishing between N loads LD, the i-th load LD is denoted as load LD-i, where i is any natural number greater than or equal to 1 and less than or equal to N. Therefore, in Fig. 1, load LD-1 refers to the first load LD, and load LD-N refers to the N-th load LD. This notation for the load LD also applies to other components corresponding to the load LD.

[0015] 1 , a three-phase distribution line HL supplies three-phase AC power to a load LD. The three-phase distribution line HL is drawn from a power distribution system in an electrical installation EE. In the first embodiment, a component including the load LD and the three-phase distribution line HL corresponding to the load is referred to as a load system UN. The load system UN may also be referred to as a load unit. In the example of FIG. 1 , N load systems are illustrated.

[0016] The ZCT 80 detects the zero-phase current flowing in the three-phase distribution line HL. As shown in FIG. 1, the three-phase distribution line HL passes through the ZCT 80 and is connected to a load LD. Therefore, the zero-phase current flowing in the three-phase distribution line HL can be detected by the ZCT 80. In the example of FIG. 1, one ZCT 80 is provided corresponding to one load LD. Therefore, the evaluation system 1 has N ZCTs 80.

[0017] The information processing device 10 evaluates the insulation deterioration state of the load system UN. The information processing device 10 acquires a detected value of the zero-phase current from the ZCT 80. According to the configuration of FIG. 1, the zero-phase current flowing in a certain three-phase distribution line HL is equivalent to the zero-phase current flowing in the load system UN corresponding to the three-phase distribution line HL. Therefore, the information processing device 10 evaluates the insulation deterioration state of the load system UN based on the detected value of the zero-phase current acquired from the ZCT 80.

[0018] When there is an imbalance in the phase currents flowing through the three-phase distribution line HL, a zero-phase current flows through the three-phase distribution line HL. Therefore, the zero-phase current is used as an evaluation index for the state of insulation deterioration of the three-phase distribution line HL. As an example, when the three-phase distribution line HL deteriorates over time, the zero-phase current increases due to the insulation deterioration of the three-phase distribution line HL. As another example, when the three-phase distribution line HL suffers mechanical damage, the zero-phase current increases due to damage to the insulating members of the three-phase distribution line HL.

[0019] As another example, even if the three-phase distribution line HL is healthy, the zero-phase current flowing through the three-phase distribution line HL may increase due to aging or an abnormality (e.g., an accident) of the load LD connected to the three-phase distribution line HL. Therefore, the zero-phase current can also be used as an evaluation index for the insulation deterioration state of the load LD. For this reason, in the first embodiment, the zero-phase current is used as an evaluation index for the insulation deterioration state of the load system UN.

[0020] The information processing device 10 acquires the zero-phase current flowing in the three-phase distribution line HL-i for any i from the ZCT 80-i. In this specification, the zero-phase current flowing in the three-phase distribution line HL-i is represented as Io(i). The information processing device 10 evaluates the insulation deterioration state of the load system UN-i based on Io(i).

[0021] According to the configuration of the first embodiment, the insulation deterioration states of N load systems UN can be individually evaluated by one information processing device 10. For convenience of explanation, the following mainly describes an example of processing in which the information processing device 10 evaluates the insulation deterioration state of one load system UN (e.g., load system UN-1).

[0022] 1 includes a data processing unit 11 and an evaluation unit 12. The data processing unit 11 acquires the detected values ​​of the zero-phase current from the ZCT 80 and generates time-series data of the detected values ​​of the zero-phase current. The time period (sampling period) at which the data processing unit 11 acquires the detected values ​​of the zero-phase current from the ZCT 80 may be any period. As an example, the data processing unit 11 acquires the detected values ​​of the zero-phase current from the ZCT 80 every second.

[0023] The data processing unit 11 may perform any data processing on the detected value of the zero-phase current obtained as described above, prior to the evaluation processing by the evaluation unit 12. Generally, the zero-phase current often contains noise components. Therefore, the data processing unit 11 may derive an evaluation target value corresponding to the zero-phase current by performing data processing to remove the noise components from the detected value of the zero-phase current.

[0024] The data processing unit 11 performs arithmetic processing using the plurality of detection values ​​for a predetermined period to calculate a representative value of the plurality of detection values ​​for the predetermined period. The representative value may be any value that indicates the central tendency of the plurality of detection values ​​for the predetermined period. Therefore, the representative value may be any predetermined summary statistic derived from the plurality of detection values ​​for the predetermined period.

[0025] The process of calculating a representative value for a predetermined period in the first embodiment is intended as an example of data processing for removing noise components from a plurality of detected values ​​for the predetermined period. Therefore, the length of the predetermined period may be set arbitrarily as long as it is a length of time considered suitable for noise removal. In the first embodiment, the predetermined period is set to 10 minutes. The predetermined period may also be referred to as a statistical value calculation period.

[0026] Averaging time-series data is an example of a process for removing noise components from the time-series data. Therefore, in the first embodiment, a case is illustrated in which the data processing unit 11 calculates an average value of a plurality of detection values ​​for a predetermined period as a representative value of the plurality of detection values ​​for the predetermined period. The data processing unit 11 calculates the representative value for each predetermined period. Therefore, the data processing unit 11 in the first embodiment generates time-series data of a 10-minute moving average of the detection values ​​of the zero-phase current.

[0027] In this specification, the zero-phase current flowing through the three-phase distribution line HL is collectively referred to as Io. The average value of Io over a predetermined period is referred to as Io_av. As described above, the data processing unit 11 generates time-series data of Io_av. Io_av may also be referred to as an average current value.

[0028] By focusing on a feature value corresponding to the zero-phase current that is different from the above-mentioned representative value, it becomes possible to consider in more detail the influence of the zero-phase current on the insulation deterioration of the load system UN. For example, the maximum value of the zero-phase current in a certain period is considered to have a particularly large influence on the insulation deterioration of the load system UN in that period.

[0029] As can be understood from the above explanations, the zero-phase current tends to increase due to insulation deterioration in the load system UN. The heat generated by the zero-phase current accelerates the insulation deterioration. Therefore, it is considered that the degree of the insulation deterioration is highly correlated with the maximum value of the zero-phase current.

[0030] Therefore, in the first embodiment, attention is focused on the maximum value of the detected value of the zero-phase current in the above-mentioned predetermined period (statistical value calculation period). Therefore, the data processing unit 11 extracts the maximum value from among the detected values ​​of the zero-phase current in the predetermined period. The data processing unit 11 extracts the maximum value in each predetermined period. Therefore, the data processing unit 11 in the first embodiment generates time series data of the maximum value of the detected value of the zero-phase current every 10 minutes.

[0031] In this specification, the maximum value of Io in a predetermined period is referred to as Io_max. As described above, the data processing unit 11 generates time-series data of Io_max. Io_max may also be referred to as the maximum current value.

[0032] The data processing unit 11 may derive an evaluation target value based on the maximum and representative values ​​of the zero-phase current derived as described above. In the first embodiment, the data processing unit 11 derives, for a certain period of time, a value obtained by subtracting the representative value for the certain period from the maximum value for the certain period as an evaluation target value corresponding to the plurality of detected values ​​for the certain period. In this specification, the value obtained by subtracting the representative value for the certain period from the maximum value of the zero-phase current for the certain period is referred to as ΔIo. ΔIo may also be referred to as a differential current value.

[0033] In the first embodiment, the data processing unit 11 derives the value obtained by subtracting Io_av from Io_max for each predetermined period as the evaluation target value. Therefore, the data processing unit 11 generates time-series data of ΔIo every 10 minutes.

[0034] That is, the data processing unit 11 calculates the following equation (1): ΔIo=Io_max-Io_av …(1) Generate 10-minute time series data of ΔIo given by

[0035] ΔIo given by equation (1) allows for more detailed consideration of the effect of the zero-phase current on insulation degradation of the load system UN than when either Io_max or Io_av is used as the evaluation target value. Therefore, in the first embodiment, the evaluation unit 12 evaluates the insulation degradation state of the load system UN using ΔIo derived by the data processing unit 11 as the evaluation target value. In this way, the evaluation unit 12 evaluates the insulation degradation state of the load system UN based on ΔIo.

[0036] In the first embodiment, it is assumed that one or more current thresholds are set for the evaluation target value. In this specification, the total number of current thresholds is denoted as M. M may be any natural number. Among the M current thresholds, the j-th current threshold is denoted as the j-th current threshold. j is any natural number greater than or equal to 1 and less than or equal to M.

[0037] In the first embodiment, a case where M is 2 or more is exemplified. That is, a case where multiple current thresholds are set for the evaluation target value is exemplified. In the first embodiment, for any j, the (j+1)th current threshold is set to a value greater than the jth current threshold. That is, as the current threshold number j increases, the current threshold corresponding to that number increases. In this way, the (j+1)th current threshold is associated with insulation deterioration that is more serious than the jth current threshold.

[0038] In the first embodiment, as an example, a case where M=3 will be described. That is, a case where three individual current thresholds, from a first current threshold to a third current threshold, are set will be described. The first current threshold is the minimum current threshold. The second current threshold is the current threshold next largest after the first current threshold. The third current threshold is the current threshold next largest after the second current threshold. The third current threshold in the first embodiment is the maximum current threshold. Therefore, the second current threshold in the first embodiment is an intermediate current threshold.

[0039] According to the findings of the inventors of the present application, when the zero-phase current is about 50 mA or less, the risk of an accident caused by insulation deterioration of the load system UN is considered to be relatively low. On the other hand, when the zero-phase current reaches about 100 mA or more, the risk of an accident caused by insulation deterioration of the load system UN is considered to be somewhat high. In addition, when the zero-phase current reaches about 200 mA or more, the risk of an accident caused by insulation deterioration of the load system UN is considered to be quite high.

[0040] Therefore, each of the M current thresholds in embodiment 1 may be set based on the above findings. As an example, the first current threshold may be 20 mA to 60 mA, the second current threshold may be 60 mA to 120 mA, and the third current threshold may be 120 mA to 300 mA. In embodiment 1, a case where the first current threshold is 50 mA, the second current threshold is 100 mA, and the third current threshold is 200 mA is exemplified.

[0041] By considering not only the evaluation target value but also the number of times that a relatively large value of the evaluation target value has occurred, the insulation deterioration state of the load system UN can be evaluated in more detail. Therefore, in the first embodiment, the evaluation unit 12 evaluates the insulation deterioration state of the load system UN based on the cumulative value of the number of times that the evaluation target value has exceeded the current threshold.

[0042] It is preferable that the evaluation result of the insulation degradation state of the load system UN be presented to the manager of the load system UN as data that is easy for the manager to understand. Therefore, in the first embodiment, the evaluation unit 12 sets a danger level indicating the evaluation result of the insulation degradation state of the load system UN based on the evaluation target value and the cumulative value of the number of times the evaluation target value exceeds the current threshold. In the first embodiment, the evaluation unit 12 sets the danger level as a discrete value.

[0043] The danger level may be used as an index representing the likelihood (risk) of an accident occurring in the load system UN due to insulation deterioration of the load system UN. As an example, the evaluation unit 12 may output the danger level to a display device (not shown) and cause the display device to display the danger level. This allows the danger level to be visually presented to the manager of the load system UN. The display device may be an internal component of the information processing device 10 or an external component of the information processing device 10.

[0044] To manually evaluate the insulation deterioration state of the load system UN from the time trend of the evaluation target value itself requires specialized knowledge about the load system UN. Therefore, by presenting the risk level, which is the evaluation result of the evaluation unit 12, to the manager as a discrete value, even a manager with little specialized knowledge can easily understand the insulation deterioration state of the load system UN. As a result, for example, the manager can plan maintenance of the load system UN according to the presented risk level.

[0045] In the first embodiment, it is assumed that multiple risk levels can be assigned. In this specification, the total number of risk levels is denoted as L. L may be any natural number equal to or greater than 2. Of the L risk levels, the kth risk level is denoted as the kth level. The kth level may also be denoted as level k. k is a number representing the risk level. k is any natural number equal to or greater than 0 and equal to or less than L-1.

[0046] In the first embodiment, for any k, the (k+1)th level is associated with insulation deterioration that is more serious than the kth level. From this, it can be said that the higher the danger level, the higher the possibility of an accident occurring in the load system UN due to insulation deterioration.

[0047] In the first embodiment, a case where L=4 is exemplified. That is, in the first embodiment, a case where four individual risk levels, from level 0 to level 3, can be assigned is exemplified. Level 0, which is the lowest (minimum) value of the risk levels, is also referred to as the lowest level. Level 0 may also be referred to as the safety level. In the first embodiment, the initial value of the risk level is set to level 0.

[0048] The first level is the next highest danger level after the zeroth level. The second level is the next highest danger level after the first level. The third level is the next highest danger level after the second level. The third level in embodiment 1 is the highest (maximum) danger level. Therefore, the first and second levels in embodiment 1 are intermediate danger levels.

[0049] In the first embodiment, there are cases where both the conditions for setting a certain risk level and the conditions for setting a lower risk level are satisfied. In this case, the evaluation unit 12 performs a determination process by preferentially adopting the conditions for setting a higher risk level, and sets the risk level.

[0050] As an example, even if an evaluation target value exceeds the first current threshold (e.g., 50 mA) described above, if the number of occurrences is relatively small, it is considered that the load system UN has not yet experienced any insulation deterioration requiring attention. Therefore, the evaluation unit 12 calculates a cumulative value of the number of times the evaluation target value exceeds the first current threshold. In this specification, this cumulative value is referred to as the first cumulative number.

[0051] Then, when the first cumulative count is less than the first count threshold, the evaluation unit 12 sets the risk level to level 0. As an example, the first count threshold may be 2 to 6. In the first embodiment, a case where the first count threshold is 4 is illustrated. Therefore, the evaluation unit 12 maintains the risk level at level 0 until the first cumulative count reaches 4. In other words, when the first cumulative count is 3 or less, the evaluation unit 12 maintains the risk level at level 0.

[0052] Even if the first cumulative count exceeds the first count threshold, if the value of the first cumulative count is not so large, it is considered that the insulation deterioration of the load system UN is minor. For this reason, in the first embodiment, the evaluation unit 12 increases the danger level to the first level when the first cumulative count is equal to or greater than the first count threshold and less than the second count threshold. The second count threshold may be set to a value greater than the first count threshold. As an example, the second count threshold may be 50 to 200. In the first embodiment, a case where the second count threshold is 100 is illustrated.

[0053] On the other hand, when the first cumulative count reaches the second count threshold, it is considered that a certain degree of insulation deterioration has occurred in the load system UN. For this reason, in the first embodiment, the evaluation unit 12 increases the danger level to the second level when the first cumulative count is equal to or greater than the second count threshold.

[0054] Even if the number of times that the evaluation target value exceeds the second current threshold (e.g., 100 mA) increases somewhat, it is considered that a certain degree of insulation deterioration has occurred in the load system UN. Therefore, the evaluation unit 12 calculates the cumulative value of the number of times that the evaluation target value exceeds the second current threshold. In this specification, this cumulative value is referred to as the second cumulative number.

[0055] In the first embodiment, the evaluation unit 12 also increases the risk level to the second level when the second cumulative count is equal to or greater than the third count threshold and less than the fourth count threshold. The fourth count threshold may be set to a value greater than the third count threshold. As an example, the third count threshold may be 2 to 6, and the fourth count threshold may be 10 to 40. In the first embodiment, a case where the third count threshold is 4 and the fourth count threshold is 20 is exemplified.

[0056] If the number of times that the evaluation target value exceeds the second current threshold becomes significantly large, it is considered that more serious insulation deterioration has occurred in the load system UN. Therefore, the evaluation unit 12 increases the danger level to the third level when the second cumulative number is equal to or greater than the fourth number threshold.

[0057] Even if the number of times that the evaluation target value exceeds the above-mentioned third current threshold (e.g., 200 mA) becomes somewhat large, it is considered that more serious insulation deterioration has occurred in the load system UN. Therefore, the evaluation unit 12 calculates the cumulative value of the number of times that the evaluation target value exceeds the third current threshold. In this specification, this cumulative value is referred to as the third cumulative number.

[0058] In the first embodiment, the evaluation unit 12 also increases the risk level to the third level when the third cumulative count is equal to or greater than the fifth count threshold. As an example, the fifth count threshold may be 2 to 6. In the first embodiment, a case where the fifth count threshold is 4 is illustrated.

[0059] As described above, the evaluation unit 12 may set a danger level based on which of the multiple current thresholds the evaluation target value has exceeded and how many times.

[0060] (Examples of healthy cases and accident cases) 2 to 15 show examples of time transitions of various data in the first embodiment. Examples of evaluation results by the information processing device 10 will be described with reference to these figures. In the electrical equipment EE of this example, the zero-phase current is measured by the ZCT 80 over a measurement period from April 1 of one year to October 31 of the following year. Then, the information processing device 10 performs evaluation based on the measurement data of the zero-phase current.

[0061] 2 to 4 show examples of time transitions of each current value obtained in a healthy load system UN. In this example, a healthy load system UN refers to a load system UN in which no accidents occurred during the entire measurement period. In this specification, cases related to a healthy load system UN are also referred to as "healthy cases."

[0062] Fig. 2 shows an example of the time course of the average current value Io_av in a healthy case, Fig. 3 shows an example of the time course of the maximum current value Io_max in a healthy case, and Fig. 4 shows an example of the time course of the difference current value ΔIo in a healthy case. Each current value in the examples of Figs. 2 to 4 is derived by the data processing unit 11.

[0063] The peaks of ΔIo in Fig. 4 (in other words, the pulse waveform) roughly correspond to the peaks of Io_max in Fig. 3. In addition, as described above, ΔIo in Fig. 4 is derived by subtracting Io_av in Fig. 2 from Io_max in Fig. 3.

[0064] Therefore, ΔIo in Fig. 4 is a signal with fewer noise components than Io_max in Fig. 3. For this reason, ΔIo can be said to be a suitable example of an evaluation target value. In Fig. 4 and Fig. 7 described below, symbol TH1 represents the first current threshold, symbol TH2 represents the second current threshold, and symbol TH3 represents the third current threshold.

[0065] Figures 5 to 7 show examples of time transitions of current values ​​obtained in a load system UN in which a fault has occurred. Figures 5 to 7 are pairs of figures with Figures 2 to 4, respectively. In this specification, a case relating to a load system UN in which a fault has occurred is also referred to as an "accident case."

[0066] FIG. 5 shows an example of the time course of Io_av in an accident case, FIG. 6 shows an example of the time course of Io_max in an accident case, and FIG. 7 shows an example of the time course of the differential current value ΔIo in an accident case. Each current value in the examples of FIGS. 5 to 7 is also derived by the data processing unit 11. ΔIo in FIG. 7 is a signal with fewer noise components than Io_max in FIG. 6. For this reason, it can be said that ΔIo is a suitable example of the evaluation target value.

[0067] In this specification, an accident refers to, for example, an event that causes a current value exceeding a predetermined reference value. The predetermined reference value may be, for example, a value of Io_av (e.g., 1000 mA) corresponding to the current value at which a protective device (e.g., a breaker) (not shown) operates. The protective circuit may be located on the three-phase distribution line HL. For example, if a ground fault or short circuit occurs in the three-phase distribution line HL, an evaluation target value that exceeds the reference value may occur. If a ground fault or short circuit occurs in the load LD, an evaluation target value that exceeds the reference value may also occur. In the example of FIG. 5, an accident occurs near the end of the measurement period.

[0068] 8 to 10 show examples of the time transition of each cumulative count in healthy cases. On the other hand, FIGS. 11 to 13 show examples of the time transition of each cumulative count in accident cases. FIGS. 11 to 13 are diagrams paired with FIGS. 8 to 10, respectively. The cumulative count at each time point in the examples of FIGS. 8 to 13 is derived by the evaluation unit 12.

[0069] FIG. 8 shows an example of the time progression of the first cumulative number in a healthy case, FIG. 9 shows an example of the time progression of the second cumulative number in a healthy case, and FIG. 10 shows an example of the time progression of the third cumulative number in a healthy case.

[0070] As shown in Figure 2 above, in the healthy case, Io_av is quite small throughout the entire measurement period. For this reason, as shown in Figure 3, in the healthy case, Io_max is also quite small throughout the entire measurement period. For this reason, as shown in Figure 4, in the healthy case, ΔIo, which is the value to be evaluated, is also quite small throughout the entire measurement period.

[0071] As shown in Fig. 4, in the healthy case, ΔIo is below the first current threshold TH1 throughout the entire measurement period. Therefore, as shown in Figs. 8 to 10, in the healthy case, the first to third cumulative counts are all 0 throughout the entire measurement period.

[0072] FIG. 11 shows an example of the time transition of the first cumulative number of accident cases, FIG. 12 shows an example of the time transition of the second cumulative number of accident cases, and FIG. 13 shows an example of the time transition of the third cumulative number of accident cases.

[0073] As shown in Figure 5 above, in the accident cases, Io_av tends to increase over time. For this reason, as shown in Figure 6, in the accident cases, Io_max also tends to increase over time. As a result, in the accident cases, ΔIo, the value to be evaluated, also tends to increase over time, as shown in Figure 7. Furthermore, in the accident cases, unlike the healthy cases, there are many peaks in ΔIo.

[0074] Furthermore, as shown in Figure 5, in the accident case, there is a significantly large peak in Io_av around January 26th, prior to the accident. For this reason, as shown in Figure 6, in the accident case, there is also a significantly large peak in Io_max around January 26th. For this reason, as shown in Figure 7, in the accident case, there is also a significantly large peak in ΔIo around January 26th.

[0075] Therefore, in the accident case, ΔIo exceeding the first current threshold TH1 frequently occurred during the measurement period, as shown in Fig. 7. As a result, in the accident case, the final first cumulative count exceeded 1000, as shown in Fig. 11. In this way, in the accident case, the first cumulative count exceeded the above-mentioned first count threshold and second count threshold.

[0076] In the accident case, ΔIo exceeding the second current threshold TH2 also occurred frequently during the measurement period. As a result, as shown in Figure 12, in the accident case, the final second cumulative count exceeded 800. In this way, in the accident case, the second cumulative count exceeded the above-mentioned third count threshold and fourth count threshold.

[0077] In the accident case, ΔIo exceeding the third current threshold TH3 occurred relatively frequently during the measurement period. As a result, as shown in Figure 13, in the accident case, the final third cumulative count exceeded 20. In this way, in the accident case, the third cumulative count exceeding the above-mentioned fifth count threshold was obtained.

[0078] The peak of ΔIo around January 26th is considered to be a precursor to an accident that occurred near the end of the measurement period. The information processing device 10 can present a risk level corresponding to such a precursor to the manager of the load system UN. Therefore, the information processing device 10 contributes to preventing accidents from occurring in the load system UN.

[0079] FIG. 14 shows an example of the time transition of the danger level in a healthy case. On the other hand, FIG. 15 shows an example of the time transition of the danger level in an accident case. FIG. 15 is a diagram paired with FIG. 14. The vertical axis of the graphs in FIGS. 14 to 15 indicates the value of the danger level. The danger level at each time point in the examples of FIGS. 14 to 15 is set by the evaluation unit 12.

[0080] As shown in Fig. 4 above, in the healthy case, ΔIo is below the first current threshold TH1 throughout the entire measurement period. Therefore, as shown in Fig. 14, in the healthy case, the danger level remains at level 0 throughout the entire measurement period.

[0081] On the other hand, as shown in Figure 7 above, in the accident cases, ΔIo tends to increase over time. Therefore, in the accident cases, the danger level increases over time. As can be seen from Figure 7, in the accident cases, the first cumulative count reaches 4 immediately after July 10th of the year that belongs to the measurement start date. Therefore, in Figure 15, the danger level increases from level 0 to level 1 at that time.

[0082] As mentioned above, in the accident case, there is a significantly large peak in ΔIo around January 26. For this reason, in Figure 15, the danger level increases from Level 1 to Level 3 around January 26. After that, the danger level is maintained at Level 3.

[0083] (effect) As described above, the technology of Patent Document 1 evaluates the insulation deterioration state of a load system based on the zero-phase current of a distribution line. However, the zero-phase current may be affected by weather conditions (e.g., temperature, humidity, and whether or not there is precipitation). The zero-phase current may also be affected by the contamination state of the load system. For this reason, the zero-phase current does not necessarily have a high correlation with the insulation deterioration state of the load system.

[0084] Therefore, the technology of Patent Document 1 cannot necessarily evaluate the insulation deterioration state of the load system with high accuracy. In particular, the technology of Patent Document 1 is likely to reduce evaluation accuracy when the load system is located outdoors. This is because when the load system is located outdoors, the load system is more susceptible to weather conditions and is more likely to become contaminated than when the load system is located indoors.

[0085] Meanwhile, the evaluation system 1 (particularly, the information processing device 10) calculates the above-mentioned ΔIo as an evaluation value from the detected value of the zero-phase current acquired from the ZCT. The information processing device 10 then evaluates the insulation deterioration state of the load system based on ΔIo. As is clear from the above explanations, ΔIo is a more suitable evaluation value than the detected value of the zero-phase current. For example, time-series data of ΔIo can succinctly express the occurrence state of pulse-like zero-phase current during the measurement period. In addition, ΔIo is a signal with fewer noise components than the detected value of the zero-phase current.

[0086] Therefore, by using ΔIo as the evaluation value, the state of insulation deterioration of the load system can be evaluated with higher accuracy than when the detected value of the zero-phase current is used as the evaluation value. For example, by using ΔIo as the evaluation value, the influence of the pulsed zero-phase current on the insulation deterioration of the load system can be taken into consideration in more detail. As a result, the information processing device 10 can evaluate the state of insulation deterioration of the load system with higher accuracy than the technology of Patent Document 1.

[0087] In addition, the information processing device 10 can evaluate the state of insulation degradation of the load system based on the cumulative value of the number of times that the evaluation target value ΔIo exceeds the current threshold. In this way, unlike the technology of Patent Document 1, the information processing device 10 can evaluate the state of insulation degradation of the load system by taking into more detailed consideration the increasing trend of the evaluation target value over time (in other words, the increasing trend of the zero-phase current over time). For this reason, the information processing device 10 can evaluate the state of insulation degradation of the load system with higher accuracy than the technology of Patent Document 1.

[0088] The technology itself for detecting some kind of abnormality based on the zero-phase current is well known. However, in the known technology, it is common to additionally measure electrical quantities other than the zero-phase current (e.g., zero-phase voltage or power supply voltage) to detect the abnormality. In contrast, the evaluation system 1 can evaluate the insulation deterioration state of the load system based on the zero-phase current without measuring the above electrical quantities. This is because the calculation of the above-mentioned ΔIo does not require measured values ​​of the above electrical quantities. In this way, the evaluation system 1 can evaluate the insulation deterioration state of the load system based on the zero-phase current with a system configuration simpler than conventional systems.

[0089] In addition, as described above, the information processing device 10 can individually evaluate the insulation deterioration state of each of the N load systems. For this reason, the evaluation system 1 is particularly suitable when N is large. The information processing device 10 can present the risk level for each of the N load systems to the manager of the load systems. This allows the manager to create maintenance plans for a large number of loads more easily than before.

[0090] [Embodiment 2] (1) Unlike the example of Fig. 1, the information processing device 10 may be located outside the electrical equipment EE. The information processing device 10 may be communicably connected to the ZCT 80 so as to acquire the detected value of the zero-phase current from the ZCT 80.

[0091] Furthermore, the information processing device 10 does not necessarily have to be a single device. For example, the information processing device 10 may be embodied by a first arithmetic unit located inside the electrical equipment EE and a second arithmetic unit located outside the electrical equipment EE. As an example, the first arithmetic unit may have a data processing unit 11, and the second arithmetic unit may have an evaluation unit 12. In this case, it is sufficient that the first arithmetic unit and the second arithmetic unit are connected to each other so that they can communicate with each other.

[0092] (2) As described above, the zero-phase current often contains noise components. Therefore, an arbitrary filter that removes the noise components of the zero-phase current may be provided between the ZCT 80 and the information processing device 10. In this case, the information processing device 10 acquires the value of the zero-phase current after the noise components have been removed by the filter.

[0093] (3) The amplitude of the zero-phase current is generally relatively small. Therefore, an optional amplifier that amplifies the amplitude of the zero-phase current may be provided between the ZCT 80 and the information processing device 10. In this case, the information processing device 10 acquires the value of the zero-phase current after being amplified by the amplifier.

[0094] As is clear from the above explanations, both a filter and an amplifier may be provided between the ZCT 80 and the information processing device 10. In this case, the information processing device 10 acquires the value of the zero-phase current after it has been amplified by the amplifier and after noise components have been removed by the filter.

[0095] (4) In the first embodiment, the representative value of a plurality of detection values ​​in a predetermined period is exemplified as the average value of the plurality of detection values ​​in the predetermined period. However, as described above, the representative value according to one aspect of the present invention may be any predetermined summary statistic derived from the plurality of detection values ​​in the predetermined period, and may be a value other than the average value.

[0096] The average value described in the first embodiment is an example of a summary statistic. Another example of a summary statistic is a median. Therefore, the data processing unit 11 may calculate the median of multiple detected values ​​in a predetermined period as a representative value of multiple detected values ​​in the predetermined period. In this specification, the median value of Io in a predetermined period is referred to as Io_md. The data processing unit 11 may calculate Io_md for each predetermined period.

[0097] The data processing unit 11 in this example derives, for each predetermined period, a value obtained by subtracting Io_md from Io_max as ΔIo. That is, the data processing unit 11 in this example calculates ΔIo using the following equation (2): ΔIo=Io_max-Io_md …(2) Generate time series data of ΔIo given by

[0098] The time-series data of ΔIo in this example also clearly expresses the occurrence of pulse-like zero-phase current during the measurement period. ΔIo in this example is also a signal with fewer noise components than the detected value of the zero-phase current.

[0099] Therefore, the evaluation unit 12 may evaluate the insulation deterioration state of the load system using ΔIo given by equation (2) as the evaluation target value. In this case, too, the insulation deterioration state of the load system can be evaluated with higher accuracy than conventional methods.

[0100] (5) The data processing unit 11 may sort the multiple detection values ​​in a predetermined period in descending order of value. Then, the data processing unit 11 may extract the remaining multiple detection values ​​after excluding (i) the first to Jth highest detection values ​​and (ii) the first to Jth lowest detection values ​​from the multiple detection values ​​after sorting. J may be any natural number as long as it is smaller than the number of multiple detection values ​​in the predetermined period.

[0101] Next, the data processing unit 11 may calculate an average value for the plurality of detected values ​​extracted as described above. In this case, the data processing unit 11 may determine the average value as a representative value. By calculating the representative value in this manner, the influence of outliers included in the plurality of detected values ​​can be more effectively eliminated.

[0102] As an example, consider a case where the number of detection values ​​in a predetermined period is 100 and J is 10. In this case, the data processing unit 11 calculates the average value of the top 11 to top 90 of the 100 detection values ​​as the representative value.

[0103] As another example, the data processing unit 11 may calculate a median value of the plurality of detected values ​​extracted as described above. In this case, the data processing unit 11 may determine the median value as the representative value.

[0104] [Software implementation example] The functions of the evaluation system 1 (hereinafter referred to as the "device" for convenience) can be realized by a program for causing a computer to function as the device, and by a program for causing a computer to function as each control block of the device (particularly each part included in the information processing device 10).

[0105] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the program. The control device and storage device execute the program, thereby realizing the functions described in each of the above embodiments.

[0106] The program may be non-transitory and may be recorded on one or more computer-readable recording media. The recording media may or may not be included in the device. In the latter case, the program may be supplied to the device via any wired or wireless transmission medium.

[0107] In addition, some or all of the functions of the control blocks can be realized by logic circuits. For example, an integrated circuit in which a logic circuit that functions as each of the control blocks is formed is also included in the scope of one aspect of the present invention. In addition, the functions of the control blocks can be realized by, for example, a quantum computer.

[0108] Furthermore, each process described in each of the above embodiments may be executed by AI (Artificial Intelligence). In this case, the AI ​​may run on the control device or on another device (for example, an edge computer or a cloud server).

[0109] 〔summary〕 An information processing device according to a first aspect of the present invention is an information processing device that evaluates the insulation deterioration state of a load system including a load and a three-phase distribution line that supplies three-phase AC power to the load, and obtains a detection value of the zero-phase current from a ZCT (Zero Current Transformer) that detects the zero-phase current flowing in the three-phase distribution line, and calculates (i) the average value of the multiple detection values ​​in the specified period, or (ii) the median value of the multiple detection values ​​in the specified period, as a representative value of the multiple detection values ​​in the specified period, extracts the maximum value from the multiple detection values ​​in the specified period, and calculates a value obtained by subtracting the representative value for the specified period from the maximum value for the specified period as an evaluation target value corresponding to the multiple detection values ​​in the specified period, and evaluates the insulation deterioration state based on the evaluation target value.

[0110] The information processing device according to a second aspect of the present invention is in the first aspect, and may evaluate the state of insulation degradation based on a cumulative value of the number of times the evaluation object value exceeds a current threshold.

[0111] The information processing device according to a third aspect of the present invention is in the second aspect, and may set a danger level as a discrete value indicating the evaluation result of the insulation degradation state based on the evaluation object value and the cumulative value.

[0112] In an information processing device according to aspect 4 of the present invention, in aspect 3, multiple current thresholds may be set, and the information processing device may set the danger level based on which of the multiple current thresholds the evaluation target value has exceeded and how many times.

[0113] An information processing method according to a fourth aspect of the present invention is an information processing method for evaluating an insulation deterioration state of a load system including a load and a three-phase distribution line that supplies three-phase AC power to the load, and includes the steps of: acquiring a detection value of the zero-phase current from a ZCT (Zero Current Transformer) that detects the zero-phase current flowing in the three-phase distribution line; calculating (i) an average value of the multiple detection values ​​in the predetermined period or (ii) a median value of the multiple detection values ​​in the predetermined period as a representative value of the multiple detection values ​​in the predetermined period; extracting a maximum value from the multiple detection values ​​in the predetermined period; calculating a value obtained by subtracting the representative value for the predetermined period from the maximum value for the predetermined period as an evaluation target value corresponding to the multiple detection values ​​in the predetermined period; and evaluating the insulation deterioration state based on the evaluation target value.

[0114] [Additional Notes] One aspect of the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of one aspect of the present invention. [Explanation of symbols]

[0115] 1. Rating System 10. Information processing equipment 11 Data processing section 12 Evaluation Section 80 ZCT HL 3 phase distribution line LD load UN load system TH1 First current threshold TH2 Second current threshold TH3 Third current threshold

Claims

1. 1. An information processing device for evaluating an insulation deterioration state of a load system including a load and a three-phase distribution line that supplies three-phase AC power to the load, A detection value of the zero-phase current is obtained from a ZCT (Zero Current Transformer) that detects the zero-phase current flowing in the three-phase distribution line; Calculating, as a representative value of the plurality of detection values ​​for a predetermined period of time, (i) an average value of the plurality of detection values ​​for the predetermined period of time, or (ii) a median value of the plurality of detection values ​​for the predetermined period of time; extracting a maximum value from the plurality of detected values ​​during the predetermined period; calculating a value obtained by subtracting the representative value for the predetermined period from the maximum value for the predetermined period as an evaluation target value corresponding to the plurality of detection values ​​for the predetermined period; An information processing device that evaluates the insulation deterioration state based on the evaluation target value.

2. The information processing apparatus according to claim 1 , wherein the insulation deterioration state is evaluated based on a cumulative value of the number of times the evaluation object value exceeds a current threshold.

3. The information processing apparatus according to claim 2 , further comprising: setting a danger level as a discrete value indicating an evaluation result of the insulation deterioration state based on the evaluation object value and the cumulative value.

4. A plurality of the current thresholds are set, The information processing apparatus according to claim 3 , wherein the danger level is set based on which of a plurality of current thresholds the evaluation target value has exceeded and how many times.

5. 1. An information processing method for evaluating an insulation deterioration state of a load system including a load and a three-phase distribution line that supplies three-phase AC power to the load, comprising: acquiring a detected value of a zero-phase current from a ZCT (Zero Current Transformer) that detects a zero-phase current flowing in the three-phase distribution line; calculating, as a representative value of the plurality of detection values ​​for a predetermined period of time, (i) an average value of the plurality of detection values ​​for the predetermined period of time, or (ii) a median value of the plurality of detection values ​​for the predetermined period of time; extracting a maximum value from the plurality of detected values ​​during the predetermined period; calculating a value obtained by subtracting the representative value for the predetermined period from the maximum value for the predetermined period as an evaluation target value corresponding to the plurality of detection values ​​for the predetermined period; and evaluating the insulation deterioration state based on the evaluation target value.

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