Discharge Event Detection System

Abstract

To provide a discharge event detection system with which, even when discharge noise generated by a discharge event occurs non-contiguously, it is possible to determine as being a charge event.SOLUTION: Provided is a discharge event detection system comprising a measurement unit for measuring noise and a determination unit. The determination unit is constituted so as to be capable of determining that a discharge event has occurred when data that supports presumption of a discharge event exists continuously for a prescribed duration, and capable of determining that a discharge event has occurred when the data that supports presumption of a discharge event becomes no longer existent before being determined that a discharge event has occurred and the measured duration for which the data that supports presumption of a discharge event is nonexistent falls within a preset continuity determination time, and when it is determination that the sum total of the duration in which the data that supports presumption of a discharge event exists continuously and the duration in which the data that supports presumption of a discharge event does not exist reaches a prescribed time.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a discharge event detection system.

Background Art

[0002] As described in Patent Document 1, a technique for detecting noise generated by a discharge accident is known. The technique described in Patent Document 1 is to detect whether a threshold value that is a criterion for the presence or absence of noise output exceeds a predetermined time by a measurement unit that detects an output at a set target frequency.

[0003] The method for detecting noise of a discharge event described in Patent Document 1 is to detect noise superimposed on the peak value of the commercial frequency in the waveform and determine the occurrence of the discharge event based on the detection result. More specifically, it is to determine the occurrence of the discharge event by following the steps of "extracting high-frequency noise with a high-pass filter", "amplifying the high-frequency noise with an amplifier", "smoothing the noise waveform with a smoothing unit", and "determining a discharge event when the noise level exceeds the threshold value for a certain period of time or more" in order.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005] By the way, the noise output superimposed on the electric circuit in a discharge event does not necessarily occur continuously and may occur discontinuously. In that case, considering the whole, there was a case where, although a level exceeding the threshold value for a discharge duration corresponding to the discharge event was output, the discharge event was not determined only because the continuity was momentarily interrupted.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The inventors of this invention have attempted to solve this problem by diligently considering it. The problem that this invention aims to solve is to provide a discharge event detection system that can determine a discharge event even when the discharge noise generated by the discharge event occurs discontinuously. [Means for solving the problem]

[0007] To solve the above problems, a discharge event detection system is provided, comprising: a measurement unit that measures noise superimposed on the voltage or current of an electrical circuit to which a load is connected; and a determination unit that determines whether or not a discharge event has occurred based on the data measured by the measurement unit, wherein the determination unit can determine that a discharge event has occurred if it can determine that data suggesting a discharge event has been continuously present for a predetermined time, and even if the state in which data suggesting a discharge event has been continuously present changes to a state in which it has not been present before the determination that a discharge event has occurred, the system can determine that a discharge event has occurred if the time measured as the time in which data suggesting a discharge event has not been present is within a preset continuity determination time, and the sum of the time in which data suggesting a discharge event has been continuously present and the time in which data suggesting a discharge event has not been present reaches the predetermined time.

[0008] Furthermore, the discharge event detection system comprises a measurement unit that measures noise superimposed on the voltage or current of an electrical circuit to which a load is connected, and a determination unit that determines whether or not a discharge event has occurred based on the data measured by the measurement unit, wherein the determination unit can determine that a discharge event has occurred if it can determine that data exceeding a threshold has continued for a predetermined time, and even if the state changes from exceeding the threshold to not exceeding the threshold before determining that a discharge event has occurred, the system can determine that a discharge event has occurred if the time measured as the time not exceeding the threshold is within a preset continuity determination time, and the sum of the time the data exceeds the threshold and the time the data does not exceed the threshold reaches the predetermined time.

[0009] Furthermore, it is preferable to have a configuration in which, if the data output is below a threshold after the continuity judgment time has been exceeded, the continuity of the data subject to judgment is reset.

[0010] Furthermore, it is preferable to configure the system to measure the time during which data does not exceed a threshold at the same time as it begins to check the continuity of data that exceeds the threshold.

[0011] Furthermore, it is preferable to configure the system to measure the time during which the data does not exceed the threshold only after a certain period of time has elapsed since the system began checking the continuity of data that exceeds the threshold.

[0012] Furthermore, the system includes a phase division unit that can distinguish between a peak time region including the region before and after a positive peak at commercial frequency, a zero-value time region before and after the output at commercial frequency becomes zero immediately after the positive peak, a peak time region including the region before and after a negative peak, and a zero-value time region before and after the output at commercial frequency becomes zero immediately after a negative peak. The determination unit checks whether data exceeding a threshold has continued for a predetermined time by determining the difference between the peak time region including the region before and after a positive peak and the zero-value time region before and after the output at commercial frequency becomes zero immediately before or after the positive peak, or the peak time including the region before and after a negative peak. It is preferable to configure the system to check the continuity of time when the threshold is not exceeded on either side of the following: the peak time region including the region before and after a positive peak, and the difference between the zero-value time region before and after the period immediately before or after a negative peak when the output at commercial frequency becomes zero; or the peak time region including the region before and after a negative peak, and the difference between the zero-value time region before and after the period immediately before or after a negative peak when the output at commercial frequency becomes zero; in order to confirm whether the transition from a state exceeding the threshold to a state not exceeding the threshold occurred only within the continuity judgment time, the system checks the continuity of time when the threshold is not exceeded on either side of the following: the peak time region including the region before and after a positive peak, and the difference between the zero-value time region before and after the period immediately before or after a positive peak when the output at commercial frequency becomes zero; or the peak time region including the region before and after a negative peak, and the difference between the zero-value time region before and after the period immediately before or after a negative peak when the output at commercial frequency becomes zero. [Effects of the Invention]

[0013] The present invention makes it possible to provide a discharge event detection system that can determine a discharge event even when the discharge noise generated by the discharge event occurs discontinuously. [Brief explanation of the drawing]

[0014] [Figure 1] This figure shows an example in which a discharge detection unit equipped with a discharge detection system is attached to the primary side of the load. [Figure 2] This diagram shows an example of the process for confirming whether or not a discharge event has occurred using a discharge detection system. [Figure 3] This figure shows an example where the data being judged fell below the threshold for a short period of time. [Figure 4] This figure illustrates an example where the data initially exceeded a threshold, then fell below the threshold after the continuation judgment time was exceeded, but then continued to exceed the threshold again. [Figure 5] This diagram illustrates that when the count trigger, which starts counting the time spent in a state where the threshold is exceeded, is turned ON, the trigger for measuring the time spent in a state where the threshold is no longer exceeded is also turned ON. [Figure 6] This diagram illustrates that when a "continuous measurement time" exists in which the value remains above a threshold for a predetermined period, the trigger for measuring the time when the value changes from a state exceeding the threshold to a state not exceeding the threshold is activated. [Figure 7] This figure shows an example of a discharge detection unit having a means for changing the discharge and a display unit being attached to the primary side of the load. [Figure 8] This diagram shows that "1" is written if the threshold is exceeded within a specified time period, and "0" is written if the threshold is not exceeded. [Figure 9] This figure shows an example of the output when continuously checking whether a threshold is exceeded within a predetermined time period, and an example of the relationship between the output content and the operation. [Figure 10]It is a diagram showing the difference between the case where discharge noise is superimposed on the commercial frequency and the case where the noise of the inverter motor is superimposed on the commercial frequency. [Figure 11] It is a diagram showing an example in which a discharge detection unit having a phase division unit is attached to the primary side of a load. [Figure 12] It is a diagram showing an example of a flow for confirming whether a discharge event has occurred using a discharge detection system having a phase division unit. [Figure 13] It is a diagram showing an example in which smoothing is performed for each region divided by a phase division unit when discharge noise is superimposed on the commercial frequency. However, the commercial frequency with noise on the upper side is shown, and the output obtained after smoothing is shown on the lower side. [Figure 14] It is a diagram showing an example in which the number of times the result of calculating the difference between the data in the peak time region (A) and the zero value time region (B) exceeds the threshold continues for a plurality of times (25 times). [Figure 15] It is a diagram showing an example in which the data to be determined is slightly below the threshold for a certain period of time. [Figure 16] It is a diagram showing an example in which the time in the state of exceeding the threshold is reset because it has exceeded the continuity determination time and fallen below the threshold, but since it exceeds the threshold again, the count trigger for the time in the state of exceeding the threshold is turned on again. [Figure 17] It is a diagram showing that when the count trigger for starting the count of the time in the state of exceeding the threshold is turned on, the trigger for measuring the time from the state of exceeding the threshold to the state of not exceeding the threshold is turned on. [Figure 18] It is a diagram showing that when there is a "continuous measurement time" that continues above the threshold for a predetermined time, the trigger for measuring the time from the state of exceeding the threshold to the state of not exceeding the threshold is operated.

Embodiments for Carrying Out the Invention

[0015] The following describes embodiments for carrying out the invention. The discharge event detection system of this embodiment includes a measurement unit 11 that measures noise superimposed on the voltage or current of the circuit to which the load EL is connected, and a determination unit 14 that determines whether or not a discharge event has occurred based on the data measured by the measurement unit 11. Furthermore, the determination unit 14 of this discharge event detection system can determine that a discharge event has occurred if it can determine that data suggesting a discharge event has been continuously present for a predetermined time (discharge confirmation time). Even if the state in which data suggesting a discharge event has been continuously present changes to a state in which it has not been present before it is determined that a discharge event has occurred, if the time measured as the time in which data suggesting a discharge event has not been present is within a preset continuity determination time, and it can be determined that the sum of the time in which data suggesting a discharge event has been continuously present and the time in which data suggesting a discharge event has not been present reaches the predetermined time, it can determine that a discharge event has occurred.Therefore, it is possible to provide a discharge event detection system that can determine a discharge event even when the discharge noise generated by the discharge event occurs discontinuously.

[0016] More specifically, the discharge event detection system comprises a measurement unit 11 that measures noise superimposed on the voltage or current of the circuit to which the load EL is connected, and a determination unit 14 that determines whether or not a discharge event has occurred based on the data measured by the measurement unit 11. The determination unit 14 is a processor such as a microcontroller, and can determine that a discharge event has occurred if it can determine that data exceeding a threshold has continued for a predetermined time (discharge confirmation time). Even if the state changes from exceeding the threshold to not exceeding the threshold before it is determined that a discharge event has occurred, if the time measured as the time not exceeding the threshold is within a preset continuity determination time, and it can be determined that the sum of the time the data exceeds the threshold and the time the data does not exceed the threshold reaches the predetermined time (discharge confirmation time), the discharge event detection system can determine that a discharge event has occurred.

[0017] Here, an embodiment will be described using a discharge event detection unit 1 equipped with a discharge event detection system as an example. As can be seen from Figure 1, the discharge event detection unit 1 of the embodiment includes a measurement unit 11 (filter unit) consisting of a CR circuit that extracts the noise output of high-frequency components of the voltage or current of the circuit, an amplification unit 12 that amplifies the noise output extracted by the measurement unit 11, a smoothing unit 13 that smooths the noise output amplified by the amplification unit 12, and a determination unit 14 capable of determining whether the noise output smoothed by the smoothing unit 13 exceeds a predetermined threshold. The discharge event detection unit 1 should be connected to the primary side of the load EL (fluorescent lamp, etc.).

[0018] Figure 2 shows an example of the process for checking whether or not a discharge event has occurred using this discharge detection system. As can be seen from Figure 2, in this example, a discontinuous output is obtained by extracting the noise output from a waveform superimposed with noise using the measurement unit 11. This output is then amplified by the amplification unit 12 to a usable size. Furthermore, the noise output is smoothed using the flattening unit to make the determination easier. After doing this, it is compared with a threshold to determine whether or not a discharge event has occurred.

[0019] In this embodiment, the determination unit 14 can determine whether the output exceeds a threshold based on pre-stored threshold determination conditions. Furthermore, the determination unit 14 can determine whether a discharge event has occurred using pre-stored discharge confirmation time conditions. In this embodiment, each of the above conditions is pre-stored in the determination condition storage unit of the determination unit 14.

[0020] For example, if data exceeding a threshold persists for a predetermined period of time (discharge confirmation time), it can be determined that a discharge event has occurred. Also, as shown in Figure 3, even if the data changes from exceeding the threshold to not exceeding the threshold before it is determined that a discharge event has occurred, if the time spent not exceeding the threshold is within a predetermined continuity judgment time, and the sum of the time spent exceeding the threshold and the time spent not exceeding the threshold reaches the predetermined time, it can be determined that a discharge event has occurred.

[0021] Furthermore, the determination unit 14 can determine whether the time during which the threshold continuously decreases reaches the continuity determination time using pre-stored continuity determination time conditions. Therefore, even if the output falls below the threshold for a predetermined time (such as 50ms) within the continuity determination time, it is possible to avoid the misjudgment that no discharge event has occurred. In other words, it is possible to detect the occurrence of a discharge event even if discontinuous discharge noise occurs. Therefore, it is possible to detect discharge noise that is always discontinuous, such as tracking. In this embodiment, the continuity determination time conditions are also pre-stored in the determination condition storage unit of the determination unit 14.

[0022] The continuity judgment time is set to prevent the event's continuity from being immediately reset even if there is a momentary period where the threshold is not exceeded. Therefore, it is preferable to set it to a short time, such as the duration of 1 to 3 cycles of the power waveform. Furthermore, as can be understood from Figure 4, it is preferable to reset the continuity of the data being judged if the data output remains below the threshold after the continuity judgment time has elapsed. Specifically, if the data remains below the threshold for a period exceeding the set continuity judgment time, the measurement count for the discharge confirmation time should be reset.

[0023] By the way, it is not necessary to have preparations in place at all times for measuring the time it takes for the data to go from exceeding the threshold to not exceeding the threshold. Therefore, it is preferable to have preparations in place for measuring that time at some point, but for example, as can be seen from Figure 5, the setting to measure the time it takes for the data to go from exceeding the threshold to not exceeding the threshold should be done at the time when you start checking the continuity of the data that is exceeding the threshold. Specifically, when the count trigger that starts counting the time it takes for the data to go from exceeding the threshold to not exceeding the threshold is turned ON, the trigger for measuring that time should also be turned ON.

[0024] Furthermore, the setting to measure the time during which the data does not exceed the threshold may be configured to be performed after a certain period of time has elapsed since the start of checking the continuity of data that exceeds the threshold. Specifically, as can be seen from Figure 6, the trigger for measuring the time during which the data returns to a state below the threshold can be activated when there is a "continuous measurement time" during which the data remains above the threshold for a predetermined period of time. In this case, the "continuous measurement time" should be set to be shorter than the discharge confirmation time.

[0025] If the output remains above a threshold for a certain period, a trigger is activated to measure the time it takes for the output to drop below the threshold. In the case of sudden noise intrusion from another device, there will be no time measured as the period when the output is below the threshold, thus preventing a false detection of a discharge event.

[0026] Furthermore, while the continuity judgment time can be pre-set in the discharge detection unit before shipment, it is also preferable to provide a change mechanism 15 so that the continuity judgment time can be changed later (see Figure 7). An example of such a change mechanism 15 is one that can be operated by a button; for example, pressing a button could display the currently set continuity judgment time on the display unit 16 or allow the set time to be changed. Alternatively, the configuration could allow the continuity judgment time to be set by connecting an external device such as a setting device in a communicative manner.

[0027] It is preferable to configure the system so that if the data output is below a threshold after the continuity judgment time has been exceeded, the measurement counters for the data that exceeded the threshold and the measurement counters for the data that was measured as time below the threshold are reset.

[0028] Furthermore, if the time measured as a period of time not exceeding the threshold falls within a predetermined continuity judgment period, the time measured as a period of time not exceeding the threshold may be treated and counted as time exceeding the threshold to determine whether or not a discharge event occurred. Alternatively, the time measured as a period of time not exceeding the threshold may be treated as such, and the count of time not exceeding the threshold and the count of time within the continuity judgment period not exceeding the threshold may be combined and used as the basis for determining whether or not a discharge event occurred.

[0029] By the way, in order to confirm the continuity of being above the threshold, measurements may be taken at predetermined time intervals, and it may be determined whether the threshold is exceeded (indicated by "1" in the examples shown in Figures 8 and 9) or not (indicated by "0" in the examples shown in Figures 8 and 9) within each time period.

[0030] In the example shown in Figure 9, the measurement of data to be compared with the discharge confirmation time condition is set to start when there are three consecutive "1"s. However, the setting to start measurement does not have to be limited to three consecutive "1"s. However, it is preferable to set the measurement of data to be compared with the discharge confirmation time condition when there are multiple consecutive "1"s. The "three consecutive" shown here refers to the state in which one cycle of the power supply waveform is measured three times in a row. Alternatively, the duration of one measurement can be arbitrarily determined.

[0031] Furthermore, while the system is set to reset the measurement time for the data compared to the discharge confirmation time condition if "0" appears three times in a row, the setting to reset the measurement does not need to be limited to three consecutive "0"s. However, it is preferable to reset the measurement if "0" appears a predetermined number of times after the measurement of the data compared to the discharge confirmation time condition has started. If the number of times "0" is displayed is less than this predetermined number, the time during that period should be treated as the time compared to the discharge confirmation time.

[0032] Here, we will describe another embodiment. As can be seen from Figure 10, noise caused by motors such as inverters is always outputting noise even though it is not a discharge event. On the other hand, when a discharge event occurs, the noise is greatly superimposed around the peak value of the commercial frequency. Therefore, even when noise caused by motors such as inverters is generated, the presence or absence of discharge noise can be determined by comparing the peak time domain, which includes the region before and after the peak at the commercial frequency, with the zero-value time domain, which includes the region before and after the output at the commercial frequency becomes zero.

[0033] To enable this, in the second example, the discharge event detection unit 1 is equipped with a phase division unit 17 (see Figure 11). This phase division unit 17 can be configured to distinguish between the output waveform extracted by the measurement unit 11 and the following: a peak time region including the region before and after a positive peak at the commercial frequency; a zero-value time region including the region immediately after the positive peak when the output at the commercial frequency becomes zero; a peak time region including the region before and after a negative peak; and a zero-value time region immediately after the negative peak when the output at the commercial frequency becomes zero.

[0034] The discharge detection unit in this example includes a measurement unit 11 (filter unit) that extracts the output waveform in the high-frequency band. It also includes an amplification unit 12 that amplifies the noise output extracted by the measurement unit 11. Furthermore, it includes a phase division unit 17 that defines a peak time domain, which includes the region before and after the peak at the commercial frequency, and a zero-value time domain, which includes the region before and after the output at the commercial frequency becomes zero. It also includes a smoothing unit 13 that smooths the output waveform for each divided phase. Furthermore, it includes a calculation unit that calculates the difference between the output at the timing of the peak time domain and the output at the timing of the zero-value time domain. Finally, it includes a determination unit 14 that determines whether the difference calculated by the calculation unit is greater than or equal to a predetermined threshold.

[0035] The determination unit 14 can check whether data exceeding the threshold has been present for a predetermined period of time by checking the duration of the time exceeding the threshold in either of the following ways: the difference between the peak time region including the region before and after a positive peak and the zero-value time region before and after the positive peak when the output at the commercial frequency becomes zero immediately before or after the positive peak; or the difference between the peak time region including the region before and after a negative peak and the zero-value time region before and after the negative peak when the output at the commercial frequency becomes zero immediately before or after the negative peak.

[0036] Furthermore, the determination unit 14 can confirm whether the transition from a state exceeding the threshold to a state not exceeding the threshold occurred only within the continuity determination time. This can be done by checking the continuity of the period during which the threshold was not exceeded by either the difference between the peak time region including the region before and after a positive peak and the zero-value time region before and after the period immediately before or after the positive peak when the output at the commercial frequency becomes zero, or by checking the difference between the peak time region including the region before and after a negative peak and the zero-value time region before and after the period immediately before or after the negative peak when the output at the commercial frequency becomes zero.

[0037] As can be seen from Figure 12, in this example, a discontinuous output is obtained by extracting the noise output from the waveform superimposed with noise using the measurement unit 11. This output is amplified by the amplification unit 12 to a usable size. Furthermore, the phase division unit 17 divides the output into phases. In addition, the noise output is smoothed using the flattening unit to make it easier to judge each divided phase. After doing this, the presence or absence of a discharge event is determined.

[0038] In this process, by smoothing each phase, a rectangular wave-shaped output, such as that shown in Figure 13, can be obtained.

[0039] When performing this type of processing, a discharge event can be determined to have occurred if the difference between the peak time domain, which includes the region before and after the peak at either the positive or negative commercial frequency, and the zero-value time domain, which includes the region before and after the output at the commercial frequency becomes zero, continuously exceeds a threshold for a predetermined time (a predetermined number of times).

[0040] In the example shown in Figure 13, when determining whether or not a discharge event has occurred, the difference between the peak time region (A), which includes the region before and after the positive peak at the commercial frequency, and the zero-value time region (B), which is immediately after the positive peak and before and after the output at the commercial frequency becomes zero, is calculated. However, it is also possible to calculate the difference between the peak time region (A), which includes the region before and after the positive peak, and the zero-value time region (B'), which is immediately before and after the output at the commercial frequency becomes zero just before the positive peak.

[0041] Furthermore, depending on the connection polarity of the plug of the load EL to the outlet, it may be more appropriate to calculate the difference between the peak time domain (A') which includes the region before and after the negative peak in the commercial frequency, and the zero-value time domain (B' or B) which is the region before and after the point immediately before or after the negative peak when the output in the commercial frequency becomes zero.

[0042] Similar to the example shown earlier, in order to determine whether or not a discharge event has occurred, it is checked whether the conditions are met, such as whether data exceeding the threshold continues for a predetermined period of time, or whether, even if the state changes from exceeding the threshold to not exceeding the threshold before it is determined that a discharge event has occurred, the time measured as not exceeding the threshold is within the pre-set continuity judgment time, and whether the sum of the time when the data exceeds the threshold and the time when it does not exceed the threshold reaches the predetermined time. In this case, the data obtained using the phase division unit 17 is used.

[0043] In the examples shown in Figures 14 and 15, the presence or absence of data exceeding a threshold is checked for each period in order to make this determination. In the examples shown in Figures 14 and 15, since noise originating from discharge events is likely to be superimposed on the peak time domain (A), which includes the region before and after the positive peak at the commercial frequency, the difference between the data in the peak time domain (A), which includes the region before and after the positive peak at the commercial frequency, and the zero-value time domain (B) immediately following the peak time domain (A) is calculated. In Figure 15, if the result of the difference calculation exceeds the threshold, "1" is displayed, and if it does not exceed the threshold, "0" is displayed.

[0044] Incidentally, as in the example shown earlier, the determination unit 14 can determine whether the output exceeds a threshold based on the threshold determination conditions. Furthermore, the determination unit 14 can determine whether a discharge event has occurred using the discharge confirmation time conditions.

[0045] For example, if data exceeding a threshold persists for a predetermined time (discharge confirmation time), it can be determined that a discharge event has occurred. Even if the data changes from exceeding the threshold to not exceeding it before it is determined that a discharge event has occurred, if the time spent not exceeding the threshold is within a pre-set continuity determination time, and the sum of the time spent exceeding the threshold and the time spent not exceeding the threshold reaches the predetermined time, it can be determined that a discharge event has occurred. Furthermore, the determination unit 14 can determine whether the time spent continuously decreasing the threshold reaches the continuity determination time using the continuity determination time condition.

[0046] The continuity judgment time is set to prevent the continuity of an event from being immediately reset, even if there is a momentary period during which the threshold is not exceeded. Therefore, it is preferable to set it to a short time, such as the duration of 1 to 3 cycles of the power waveform (e.g., 50ms).

[0047] It is preferable that the continuity of the data being judged be reset if the data output remains below the threshold after the continuity judgment time has been exceeded. Specifically, if the data continues to fall below the threshold after the time set as the continuity judgment time has been exceeded, the measurement count of the time when the data was above the threshold should be reset. In the example shown in Figure 16, the count is restarted because data exceeding the threshold occurred again after it had been reset once.

[0048] Furthermore, as can be seen from Figure 17, the setting to measure the time during which the data does not exceed the threshold can be done at the same time as when you start checking for the continuity of data that exceeds the threshold, and as can be seen from Figure 18, the setting to measure the time during which the data does not exceed the threshold can be done after a certain period of time has elapsed since you started checking for the continuity of data that exceeds the threshold, as in the previous example.

[0049] Furthermore, by determining whether or not a threshold value is exceeded in the region divided by the phase division unit 17, it can be used in the same way as shown in Figure 9.

[0050] The present invention has been described above with reference to the embodiments described above, but the present invention is not limited to the above embodiments and can be implemented in various forms. For example, it is not necessary to use a unit, and it is possible to make separately arranged devices function as a system. [Explanation of symbols]

[0051] 1. Discharge event detection unit 11 Measurement Unit 14 Judgment section 17 Phase division section

Claims

1. A discharge event detection system comprising: a measurement unit that measures noise superimposed on a voltage or current of an electric circuit to which a load is connected; and a determination unit that determines whether a discharge event has occurred based on data measured by the measurement unit, the determination unit can determine that a discharge event has occurred if it can determine that data inferring a discharge event exists continuously for a predetermined period of time; Even if the state where data inferring a discharge event continuously exists changes to the state where no data inferring a discharge event exists before it is determined that a discharge event has occurred, the time measured as the time when no data inferring a discharge event exists is within a predetermined continuity determination time, A discharge event detection system that can determine that a discharge event has occurred if it can be determined that the sum of the time during which data suggesting a discharge event continues to exist and the time during which no data suggesting a discharge event exists reaches the predetermined time.

2. A discharge event detection system comprising: a measurement unit that measures noise superimposed on a voltage or current of an electric circuit to which a load is connected; and a determination unit that determines whether a discharge event has occurred based on data measured by the measurement unit, the determination unit can determine that a discharge event has occurred when it can determine that data exceeding the threshold value continues for a predetermined period of time; Even if the state where the threshold is exceeded changes to a state where the threshold is not exceeded before it is determined that a discharge event has occurred, the time measured as the time when the threshold is not exceeded is within a preset continuity determination time, A discharge event detection system that can determine that a discharge event has occurred if it can be determined that the sum of the time during which data exceeds a threshold and the time during which data does not exceed the threshold reaches the predetermined time.

3. 3. The discharge event detection system according to claim 1, wherein if the data output is equal to or less than the threshold value after the continuity determination time has elapsed, the continuity of the data to be determined is reset.

4. A discharge event detection system as described in any one of claims 1 to 3, wherein the setting that enables measurement of the time during which data does not exceed the threshold is performed at the timing when the continuity of data exceeding the threshold begins to be confirmed.

5. A discharge event detection system as described in any one of claims 1 to 4, wherein the setting that enables measurement of the time during which data does not exceed the threshold is performed after a certain period of time has elapsed since the continuity of data exceeding the threshold began to be confirmed.

6. a phase dividing unit that can distinguish and define the output waveform extracted by the measuring unit into a peak time region including a region before and after a positive peak at the commercial frequency, a zero value time region immediately after the positive peak and before and after which the output at the commercial frequency becomes zero, a peak time region including a region before and after a negative peak, and a zero value time region immediately after the negative peak and before and after which the output at the commercial frequency becomes zero, In order to confirm whether data exceeding the threshold value continues for a predetermined period of time, the determination unit checks the continuity of the time during which the threshold value is exceeded on either side of the difference between a peak time region including the region before and after a positive peak and a zero value time region before and after which the output at the commercial frequency becomes zero immediately before or after the positive peak, or the difference between a peak time region including the region before and after a negative peak and a zero value time region before and after which the output at the commercial frequency becomes zero immediately before or after the negative peak, 3. The discharge event detection system according to claim 1 or 2, wherein, in order to confirm whether the change from a state in which the threshold was exceeded to a state in which the threshold was not exceeded only occurs within the continuity determination time, the continuity of the time in which the threshold was not exceeded is confirmed on either side by checking the difference between a peak time region including the region before and after a positive peak and a zero value time region before and after which the output at the commercial frequency becomes zero immediately before or after the positive peak, or by checking the difference between a peak time region including the region before and after a negative peak and a zero value time region before and after which the output at the commercial frequency becomes zero immediately before or after the negative peak.

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