Tracking Sign Detection Device

Abstract

To provide a tracking sign detector which can detect a sign of tracking before a spark discharge is caused by tracking, and accurately determine the sign and take measures before a fire occurs.SOLUTION: A tracking sign detector 1 includes: an environmental sensor 11 for measuring the moisture and the temperature of at least around an outlet plug; a noise detection unit 12 for detecting output of noise that overlaps with the voltage or the current of a wire line; and an operation unit 13 for determining the presence or absence of a sign of tracking on the basis of information measured by the environmental sensor 11 and the noise output detected by the noise detection unit.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a tracking sign detection device that detects signs of tracking occurring in an electrical outlet plug.

Background Art

[0002] Tracking is a phenomenon in which dust accumulates in the gap between the socket and the electrical outlet plug, the accumulated dust absorbs moisture to form a conductive path between the plug blades, a minute current flows through the conductive path to progress insulation degradation, and a large current flows to cause ignition. As a means for detecting tracking, as described in Patent Document 1, an electrical outlet that detects a temperature rise of the plug is known. Further, as described in Patent Document 2, detecting a light emission phenomenon generated by the occurrence of tracking by a light receiving element provided in the electrical outlet has also been performed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

[0004] However, the methods for detecting the occurrence of tracking by detecting an increase in the temperature or light emission of the plug, as described in Patent Document 1 or 2, all detect a state in which spark discharge has already started, and there is a risk of a fire occurring even if detection is possible.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The inventor of the present invention has made efforts to solve this problem through intensive studies. The problem to be solved by the present invention is to provide a tracking omen detection device that can detect an omen of tracking before the occurrence of spark discharge due to tracking, further determine the omen with high accuracy, and take countermeasures before ignition.

Means for Solving the Problem

[0006] In order to solve the above problems, a tracking omen detection device is provided, which includes at least an environmental sensor capable of measuring the humidity and temperature at the periphery of a power plug, a noise detection unit capable of detecting a noise output superimposed on the voltage or current of a wiring path, and an arithmetic unit capable of determining the presence or absence of an omen of tracking based on the information measured by the environmental sensor and the noise output detected by the noise detection unit.

[0007] Further, after the arithmetic unit determines the presence or absence of a first omen using the humidity information measured by the environmental sensor and the noise output detected by the noise detection unit, it can be configured to determine the presence or absence of a second omen with a higher probability of tracking occurrence than the first omen using the temperature information measured by the environmental sensor and the noise output detected by the noise detection unit.

[0008] Further, it is preferably configured such that the arithmetic unit determines that a first omen is detected when the noise output value exceeds a first threshold, and determines that a second omen is detected when the noise output value exceeds a second threshold higher than the first threshold.

[0009] Further, it is preferably configured such that the arithmetic unit determines that a first or second omen is detected when the amount of change per unit time of the humidity and / or temperature measured by the environmental sensor exceeds a predetermined value.

[0010] Further, it is preferably configured such that the arithmetic unit determines that a first or second omen is detected when the time during which the noise output value continuously exceeds the threshold exceeds a predetermined time.

[0011] In addition, the environmental sensor can detect a phenomenon that occurs along with the occurrence of tracking, and the arithmetic unit is preferably configured to be able to determine the occurrence of tracking based on the information of the phenomenon detected by the environmental sensor, the noise output value, and / or the history information of the tracking sign detection.

Advantages of the Invention

[0012] In the present invention, it is possible to provide a tracking sign detection device that can detect a sign of tracking before the occurrence of spark discharge due to tracking, further determine the sign with high accuracy, and take measures before ignition.

Brief Description of the Drawings

[0013]

Figure 1

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Embodiments for Carrying Out the Invention

[0014] The following describes embodiments for carrying out the invention. As can be understood from what is shown in FIG. 1, the tracking omen detection device 1 of this embodiment includes an environmental sensor 11 capable of measuring at least the humidity and temperature at the periphery of the power plug 3, a noise detection unit 12 capable of detecting a noise output superimposed on the voltage or current of the wiring path, and an arithmetic unit 13 capable of determining the presence or absence of a tracking omen based on the information measured by the environmental sensor 11 and the noise output detected by the noise detection unit 12. Therefore, it is possible to provide a tracking omen detection device that can detect the omen of tracking before the occurrence of spark discharge due to tracking, further determine the omen with high accuracy, and take measures before ignition.

[0015] The tracking omen detection device 1 of this embodiment is used by being connected to the power outlet 2 in order to detect the omen of tracking in the power plug 3 inserted into the power outlet 2. The tracking omen detection device 1 in the example shown in FIG. 2 is installed inside a power outlet box 21 equipped with the power outlet 2.

[0016] As can be understood from what is shown in FIG. 1, the tracking omen detection device 1 in this example includes an arithmetic unit 13 connected to the environmental sensor 11 and the noise detection unit 12, and an output unit 14 connected to the arithmetic unit 13. The output unit 14 can transmit the arithmetic result of determining the presence or absence of a tracking omen by the arithmetic unit 13 based on the information from the environmental sensor 11 and the noise detection unit 12 to the owner's mobile terminal 5 or a display device (not shown) via the cloud 4, or output an electrical signal for cutting off the power supply to the power outlet 2 according to the arithmetic result. Further, the tracking omen detection device 1 in this example includes a power supply unit 15 capable of supplying electricity to each circuit from a commercial power supply and converting an alternating current into a direct current. Hereinafter, the environmental sensor 11 and the noise detection unit 12 will be described.

[0017] As can be understood from being shown in FIGS. 1 and 3, the environmental sensor 11 of this embodiment includes a humidity sensor 111 capable of detecting the humidity at the periphery of the plug blade 31 provided in the power outlet plug 3, a temperature sensor 112 capable of detecting the temperature at the periphery of the plug blade 31, and a gas sensor 113 capable of detecting the carbon dioxide concentration at the periphery of the plug blade 31. The configuration of the environmental sensor 11 is not limited to these, and the type and quantity of sensors can be set as needed. For example, an optical sensor capable of detecting light emission at the periphery of the plug blade 31 may be provided. By providing such an environmental sensor 11, it becomes possible to detect a change when a change occurs in environmental information such as the humidity and temperature at the periphery of the power outlet plug 3.

[0018] Further, the environmental sensor 11 may be provided with a measurement unit 114 to which these sensors are connected, and configured to output information such as temperature and humidity detected by each sensor to the measurement unit 114. The measurement unit 114 of the embodiment can measure the amount of change of each element over time based on the information, and can record the information and the amount of change. The measurement unit 114 of the embodiment is connected to the calculation unit 13, and environmental information such as humidity and temperature obtained by the environmental sensor 11 is sent to the calculation unit 13.

[0019] As can be understood from being shown in FIG. 3, the noise detection unit 12 of this embodiment includes a filter 121 that extracts a noise output of a high-frequency component superimposed on the voltage or current of the wiring line, an amplification unit 122 that amplifies the noise output extracted by the filter 121, a smoothing unit 123 that smooths the noise output amplified by the amplification unit 122, and a determination unit 124 that determines whether the noise output smoothed by the smoothing unit 123 exceeds a predetermined threshold value.

[0020] By providing the filter 121 in the noise detection unit 12, when noise is superimposed on the wiring path due to a sign of tracking, specific frequency components of the noise can be extracted. In the embodiment, the high-frequency components of the noise are extracted by the filter 121. The extracted noise output is preferably amplified by the amplification unit 122 and then smoothed by the smoothing unit 123. By smoothing the data of the extracted noise output, it becomes possible to determine whether the noise output exceeds a threshold value. In the embodiment, this determination is made by the determination unit 124 provided in the noise detection unit 12, and the determination result is sent to the calculation unit 13. Note that the configuration may be such that the determination unit 124 is not provided in the noise detection unit 12, the noise output detected by the noise detection unit 12 is sent to the calculation unit 13, and the determination is made by the calculation unit 13.

[0021] The calculation unit 13 to which information from the environment sensor 11 and the noise detection unit 12 is sent can determine the presence or absence of a sign of tracking using this information. Hereinafter, the procedure for determining the sign of tracking by the calculation unit 13 of the present embodiment will be described.

[0022] As described above, tracking occurs through the following process: (1) dust accumulates on the plug blades 31, (2) the dust absorbs moisture in the air, (3) a conductive path is formed between the plug blades 31 by the dust that has absorbed moisture, and a minute current flows, generating Joule heat, (4) the insulation deterioration of the plug blades 31 progresses due to the Joule heat, and (5) a large current flows and spark discharge occurs.

[0023] The tracking sign detection device 1 of the embodiment detects changes in the humidity and temperature at the periphery of the plug blades 31 that can occur in such a process, and determines the presence or absence of a sign of tracking. As a first step, the calculation unit 13 determines whether the humidity at the periphery of the plug blades 31 exceeds a predetermined threshold value regarding the phenomenon of (2) above, and turns on or off the sign detection flag. Then, as a second step, regarding the phenomenon of (3) above, the calculation unit 13 determines whether the temperature at the periphery of the plug blades 31 exceeds a predetermined threshold value, and turns on or off the sign detection flag.

[0024] In addition, preferably, in conjunction with these environmental information, determination is also made using the noise output that is superimposed on the voltage or current of the wiring path when a minute current flows between the plug blades 31. By detecting such a noise output by the noise detection unit 12 and using it for determination in conjunction with the environmental information, it becomes possible to further improve the accuracy of the determination.

[0025] In the present embodiment, when a prediction detection flag is turned on based on the humidity information measured by the environmental sensor 11 and the noise output measured by the noise detection unit 12, it is determined that there is a first prediction of tracking. Subsequently, when a prediction detection flag is turned on based on the temperature information measured by the environmental sensor 11 and the noise output measured by the noise detection unit 12, it is determined that there is a second prediction with a higher degree of danger than the first prediction. In this way, by making a determination using the humidity and temperature information step by step based on the generation principle of tracking, and further using the noise output for each determination, it is possible to issue a warning with high accuracy regarding the degree of danger of the occurrence of tracking.

[0026] Incidentally, the output value of the noise superimposed on the wiring path due to the occurrence of the phenomenon in (3) above gradually increases as the current flowing between the plug blades 31 increases. Therefore, a threshold value of the noise output value corresponding to the magnitude of the current flowing between the plug blades 31 can be set and used for determining the presence or absence of a prediction of tracking. In the example shown in FIG. 4, an arbitrary voltage noise value that can be detected at the stage where dust deposited on the plug blade 31 contains moisture and a conductive path is formed between the plug blades 31 is set as the first threshold value, and an arbitrary voltage noise value that can be detected at the stage where the insulation deterioration between the plug blades 31 progresses is set as the second threshold value. Also, an arbitrary voltage noise value that can be detected when tracking occurs and spark discharge occurs is set as the third threshold value.

[0027] If the configuration is such that the prediction detection flag is turned on when the noise output value exceeds these thresholds, more accurate determination can be made corresponding to the stepwise change in the magnitude of the current flowing through the plug blade 31 based on the generation principle of tracking. Specifically, it is preferable to determine that there is a first sign when the humidity exceeds a predetermined threshold and the noise output value exceeds the first threshold, and to determine that there is a second sign when the temperature exceeds a predetermined threshold and the noise output value exceeds the second threshold.

[0028] Also, instead of simply turning on the prediction detection flag when the environmental information exceeds the threshold, the configuration may be such that the prediction detection flag is turned on when a rapid change amount occurs within a predetermined time. Further, for the noise output value, it is preferable to adopt a configuration in which the prediction detection flag is turned on when the state of exceeding the threshold continues for a predetermined time. In the example shown in FIG. 5, it is determined that there is a first sign when the humidity changes by a predetermined amount or more within a predetermined time and the state where the noise output value exceeds the first threshold continues for a predetermined time or more. Subsequently, it is determined that there is a second sign when the temperature changes by a predetermined amount or more within a predetermined time and the state where the noise output value exceeds the second threshold continues for a predetermined time or more. With such a configuration, it is possible to suppress making an incorrect determination by picking up changes in the environment and noise output due to accidental factors other than tracking, and to improve the accuracy of determining the prediction of tracking.

[0029] In order to improve the accuracy of determining the presence or absence of an omen based on humidity information, a plurality of temperature sensors may be further provided in the tracking omen detection device 1. For example, in addition to the temperature sensor 112 capable of detecting the temperature at the periphery of the plug blade 31, a temperature sensor capable of measuring the room temperature of the room where the outlet 2 is installed, or a temperature sensor capable of measuring the outside air temperature of the building where the outlet 2 is installed can be provided. With such a configuration of providing a plurality of temperature sensors, it becomes possible to detect whether the environment around the outlet 2 is in a situation where tracking is likely to occur. For example, when a difference equal to or greater than a predetermined value occurs between the temperature at the periphery of the plug blade 31 and the room temperature, or between the room temperature and the outside air temperature, the conditions for dew condensation to occur are met and the dust between the plug blades 31 is likely to become moist, so it can be said that it is a situation where tracking is likely to occur. By capturing such a situation where tracking is likely to occur and reflecting it in the on / off operation of the omen detection flag, the determination of the omen can be made more accurately.

[0030] In addition, it is preferable to provide the environmental sensor 11 with sensors such as a gas sensor 113 capable of detecting the concentration of carbon dioxide and its changes, and an optical sensor capable of detecting light emission at the periphery of the plug blade 31, which can detect phenomena that occur with the occurrence of tracking. By providing these sensors, it becomes possible to detect carbon dioxide generated when dust, the outlet plug 3, the outlet 2, etc. burn when tracking occurs, and light emission occurring at the periphery of the plug blade 31. When an increase in carbon dioxide concentration or a light emission phenomenon is detected, by making a determination in combination with the noise output value, it becomes possible to accurately determine whether tracking has actually occurred.

[0031] Furthermore, not only determine that tracking has occurred when the carbon dioxide concentration exceeds the threshold value, but also it may be configured to determine the occurrence based on whether a rapid change amount has occurred within a predetermined time. Regarding the noise output value, it is preferable to configure the determination of the occurrence of tracking in consideration of whether the state of exceeding the threshold value has continued for a predetermined time. In the example shown in FIG. 5, it is determined that tracking has occurred when the carbon dioxide concentration detected within a predetermined time has changed by a predetermined amount or more and the state where the noise output value exceeds the third threshold value has continued for a predetermined time or more. By adopting such a configuration, the accuracy of determining the occurrence of tracking can be further improved.

[0032] In addition, for the determination of the occurrence of tracking, the history information of the past omen detection information can also be referred to and used. By using the history information of omen detection, it becomes possible to make a more accurate determination.

[0033] Next, an example of the flow in which the arithmetic unit 13 determines the presence or absence of a tracking omen and the occurrence of tracking will be described.

[0034] In the example shown in FIG. 6, for the presence or absence of the first omen, it is determined using the humidity information and the noise output. Specifically, first, it is determined whether the change amount of the humidity exceeds a predetermined value (S001). If it is determined that the change amount of the humidity exceeds the predetermined value, it can be reported that humidity abnormality has been detected (S002). Then, in the step of determining whether the noise output value superimposed on the voltage is equal to or greater than the first threshold value (S003), if it is determined that the noise output value is equal to or greater than the first threshold value, further, it is determined whether the state where the noise output value is equal to or greater than the first threshold value has continued for a predetermined time or more (S004). If the state where the noise output value is equal to or greater than the first threshold value has continued for a predetermined time or more, it is determined that the first omen has been detected (S005), and an alarm based on the determination result is reported (S006). When the alarm indicating that the first omen has been detected is reported in S006, the process proceeds to the step of determining the presence or absence of the second omen.

[0035] In addition, when it is determined in step S001 that humidity abnormality is not detected, or when the alarm reported in step S002 is confirmed and released by the user (S011), the process also proceeds to the step of determining the presence or absence of the second sign. When it is determined in step S003 that the noise output value is less than the first threshold, or when it is determined in step S004 that the state where the noise output value is equal to or greater than the first threshold has not continued for a predetermined time or more, the process also proceeds to the step of determining the presence or absence of the second sign.

[0036] In the example shown in FIG. 7, for the presence or absence of the second sign, it is determined using temperature information and noise output. First, it is determined whether the change amount of the temperature exceeds a predetermined value (S101). When it is determined that the change amount of the temperature exceeds the predetermined value, it is possible to report that temperature abnormality has been detected (S102). Thereafter, in the step of determining whether the noise output value superimposed on the voltage is equal to or greater than the second threshold (S103), when it is determined that the noise output value is equal to or greater than the second threshold, further, it is determined whether the state where the noise output value is equal to or greater than the second threshold has continued for a predetermined time or more (S104). When the state where the noise output value is equal to or greater than the second threshold has continued for a predetermined time or more, it is determined that the second sign has been detected (S105), and an alarm based on the determination result is reported (S106). When the alarm indicating that the second sign has been detected is reported in S106, the process proceeds to the step of determining whether tracking has occurred.

[0037] In addition, when it is determined in step S101 that temperature abnormality is not detected, or when the alarm reported in step S102 is confirmed and released by the user (S111), the process also proceeds to the step of determining the occurrence of tracking. When it is determined in step S103 that the noise output value is less than the second threshold, or when it is determined in step S104 that the state where the noise output value is equal to or greater than the second threshold has not continued for a predetermined time or more, the process also proceeds to the step of determining the occurrence of tracking.

[0038] In the example shown in FIG. 8, for the determination of whether tracking has occurred, the determination is made using the information on the carbon dioxide concentration and the noise output. First, it is determined whether the change amount of the carbon dioxide concentration exceeds a predetermined value (S201). If it is determined that the change amount of the carbon dioxide concentration exceeds the predetermined value, it is possible to report that an abnormality in the carbon dioxide concentration has been detected (S202). Thereafter, in step (S203) of determining whether the noise output value superimposed on the voltage is equal to or greater than a third threshold value, if it is determined that the noise output value is equal to or greater than the third threshold value, further, it is determined whether the state in which the noise output value is equal to or greater than the third threshold value continues for a predetermined time or more (S204). If it is determined that the state in which the noise output value is equal to or greater than the third threshold value continues for a predetermined time or more, it is determined that the occurrence of tracking has been detected (S205), an alarm notifying the occurrence of tracking is reported, and the current flowing to the outlet 2 is cut off (S206). Thereafter, it returns to the step of determining the presence or absence of the first sign again, and the same determination process is repeated.

[0039] As described above, the present invention has been described by taking the embodiments as examples, but the present invention is not limited to the above embodiments and can be in various forms. For example, the tracking sign detection device 1 can be in the form of an adapter as in the example shown in FIG. 9 in addition to the form of being installed in the outlet box 21. If the tracking sign detection device 1 is in the form of an adapter, it is preferable because it becomes easy to attach and detach from the outlet 2, and it is possible to move the installation location or install it retroactively.

Explanation of reference numerals

[0040] 1 Tracking sign detection device 11 Environmental sensor 12 Noise detection unit 13 Arithmetic unit 2 Outlet 3 Outlet plug 31 Plug blade

Claims

1. An environmental sensor capable of measuring at least the humidity and temperature at the periphery of a power outlet, a noise detection unit capable of detecting a noise output superimposed on the voltage or current of a wiring path, and an arithmetic unit capable of determining the presence or absence of a tracking omen based on the information measured by the environmental sensor and the noise output detected by the noise detection unit. A tracking omen detection device comprising the same.

2. After the arithmetic unit determines the presence or absence of a first omen using the humidity information measured by the environmental sensor and the noise output detected by the noise detection unit, the arithmetic unit uses the temperature information measured by the environmental sensor and the noise output detected by the noise detection unit. The tracking omen detection device according to claim 1, wherein the presence or absence of a second omen with a higher likelihood of tracking occurrence than the first omen can be determined.

3. The arithmetic unit can determine that a first omen is detected when the noise output value exceeds a first threshold, and can determine that a second omen is detected when the noise output value exceeds a second threshold higher than the first threshold. The tracking omen detection device according to claim 2.

4. The arithmetic unit can determine that a first or second omen is detected when the amount of change per unit time of the humidity and / or temperature measured by the environmental sensor exceeds a predetermined value. The tracking omen detection device according to any one of claims 1 to 3.

5. The arithmetic unit can determine that a first or second omen is detected when the time during which the noise output value continuously exceeds the threshold exceeds a predetermined time. The tracking omen detection device according to any one of claims 1 to 4.

6. The environmental sensor is capable of detecting a phenomenon that occurs with the occurrence of tracking, and the arithmetic unit can determine the occurrence of tracking based on the information of the phenomenon detected by the environmental sensor, the noise output value, and / or the history information of tracking omen detection. The tracking omen detection device according to any one of claims 1 to 5.

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