JP7337441B2 - Discharge detection unit - Google Patents

Description

The present invention relates to a discharge detection unit.

It is known to provide a noise output detection device, as described in US Pat. Conventionally, a noise output detection device is provided on the secondary side of the main breaker provided in the distribution board so as to be adjacent to the main breaker, and current and voltage are supplied to the load using this noise output detection device. It detected the presence or absence of discharge accidents in the range of

Japanese Unexamined Patent Application Publication No. 2017-173008

By the way, among the noise generated by the discharge, the noise having the frequency in the conduction noise band propagates through the electric wire. On the other hand, as can be understood from FIG. 18, among the noises generated by the discharge, the output of the noise with frequencies in the radiation noise band is attenuated as the distance between the discharge detection unit and the point where the discharge event occurs increases. There was a possibility that the output could not be detected. For this reason, there has been a tendency to avoid using frequencies in the radiation noise band for detecting discharge accidents. However, the present inventors attempted to determine the presence or absence of a discharge accident by a new method by using this phenomenon.

The present invention has been made under such circumstances, and a problem to be solved by the present invention is to provide a discharge detection unit capable of changing the threshold value according to discharge measurement conditions.

In order to solve the above problem, a detection unit that detects an output at a target frequency set to detect noise generated by an electric discharge accident, and a threshold that is used to set a threshold that serves as a criterion for determining the presence or absence of noise output. and setting means, wherein the threshold value can be selected from among a plurality of values.

Further, it is preferable that a setting operation section operated when setting a threshold value, which is used as a criterion for determining the presence or absence of noise output, be operable from the outside of the housing of the discharge detection unit.

Moreover, it is preferable to have a configuration including target frequency changing means used to change the target frequency.

In addition, it is preferable to have a storage unit and a control unit, read the information stored in the storage unit, and control the control unit so that the threshold value is set by the threshold value setting unit based on the read information.

According to the present invention, it is possible to provide a discharge detection unit that can change the threshold according to discharge measurement conditions.

4 is a perspective view of the discharge detection unit in the embodiment; FIG. FIG. 4 is a diagram showing a distribution board in which a discharge detection unit is attached to the secondary side of a main breaker; 1 is a perspective view of an outlet and a discharge detection unit attached to the outlet; FIG. FIG. 4 is a diagram showing a relationship between an example of arrangement of discharge detection units and a discharge generation location; 4 is a diagram showing a configuration example of a discharge detection unit; FIG. FIG. 10 is a diagram showing an example of “relationship between distance from discharge detection unit to discharge generation location, frequency, and output”, “target frequency”, and “threshold setting value”; FIG. 10 is a diagram showing an example of the relationship between distances to other houses and set values of detectable distances; FIG. 10 is a diagram showing an example in which an output value exceeds a threshold for a predetermined period of time or longer; FIG. 3 is a diagram showing a distribution board in which a discharge detection unit having threshold setting means and target frequency changing means is attached to the secondary side of a main breaker; FIG. 4 is a diagram showing a configuration example of a discharge detection unit capable of manipulating a target frequency; FIG. 10 is a diagram showing an example of change in threshold setting when the target frequency is changed; FIG. 4 is a diagram showing a configuration example of a discharge detection unit provided with a storage section; FIG. 10 is a diagram showing a setting example of threshold values to be stored; FIG. 10 is a diagram showing a state in which a disconnection signal can be transmitted from the discharge detection unit to the main breaker; FIG. 4 is a diagram showing an example of a discharge detection unit that can cut off a breaker by causing a pseudo electric leakage. FIG. 4 is a diagram showing a configuration example of a discharge detection unit that detects noise from current measured by CT; FIG. 4 is a diagram showing a configuration example of a discharge detection unit that detects noise from voltage; FIG. 10 is a diagram showing an example of "relationship between the distance from the discharge detection unit to the discharge generation point, the frequency, and the output";

Modes for carrying out the invention are shown below. As can be understood from FIG. 1, the discharge detection unit 1 of the present embodiment includes a detection section that detects an output at a target frequency set to detect noise generated by a discharge accident, Threshold value setting means 11 used to set a threshold value that serves as a criterion for determining the presence or absence of noise output. Also, the threshold can be selected from a plurality of thresholds. Therefore, the discharge detection unit 1 can change the threshold according to the discharge measurement conditions. The target frequency in this embodiment means a target frequency for detecting noise generated by a discharge accident. By the way, it is possible to detect the noise generated by the discharge accident even in the frequency band of the conduction noise. However, noise in such a frequency band includes noise generated during operation of home electric appliances. Therefore, it is preferable that the target frequency band be a frequency band of radiated noise that does not contain noise such as that of home electric appliances. Objects can be picked up by the detector.

As can be seen from FIGS. 2 to 4, such a discharge detection unit 1 is preferably attached to the distribution board 3 or the outlet 91 for use. In the discharge detection unit 1 of the embodiment, the setting operation section 12 that is operated when setting a threshold value that serves as a criterion for determining the presence or absence of noise output can be operated from the outside of the housing 10 . By operating the setting operation unit 12 provided on the surface of the housing 10 to set the threshold value, the determination condition can be changed. More specifically, when the setting operation unit 12 is operated, the setting value of the threshold value setting unit 13 used for the determination made by the determination unit 23 is changed. In this embodiment, the setting operation unit 12 is described as being changed by human operation, but it is of course possible to transmit a signal from the outside to set the threshold.

The example shown in FIG. 2 is a case where the discharge detection unit 1 is provided in the distribution board 3 . The discharge detection unit 1 is provided on the secondary side of the main breaker 31 and on the primary side of the branch breaker 34 . The discharge detection unit 1 in the example shown in FIG. 3 is connected to an outlet 91 . The discharge detection unit 1 of this example includes a plug portion 41 that is inserted into an outlet 91 provided in a building 81 or the like. Electricity passing through the plug portion 41 is used to operate the discharge detection unit 1. ing. This discharge detection unit 1 is provided with an outlet section 42 to which a load plug or the like can be connected.

The discharge detection unit 1 of the example shown in FIG. A determination unit 23 for making determination based on the result obtained by the amplification unit 22 and an output unit 24 for outputting the determination result are provided. Among them, the filter unit 21 functions as a detection unit.

Here, what happens when the threshold setting unit 13 changes the set value that serves as the threshold for determining that there is a discharge will be described. As shown in FIG. 6, it is assumed that the target frequency is determined at a specific portion of the radiation noise frequency band. For the sake of explanation, cases where the discharge generation locations are at positions 5 m, 25 m, and 50 m away from the discharge detection unit 1 will be described. When the set value of the threshold value setting unit 13 is set as the first threshold value, when there is a noise output at a place where the distance between the discharge detection unit 1 and the discharge occurrence point is as short as 5 m, an output exceeding the threshold value can be detected. can. On the other hand, when there is a noise output due to a discharge event in a place where the distance between the discharge detection unit 1 and the discharge occurrence point is as far as 25 m or 50 m, the distance to the discharge detection unit 1 is long even if the discharge event occurs. is attenuated, it is set so that it becomes equal to or less than the first threshold and the occurrence of discharge cannot be detected.

When the set value of the threshold value setting unit 13 is set to a second threshold lower than the first threshold, the noise output is equal to or higher than the second threshold even when the distance between the discharge detection unit 1 and the discharge occurrence point is 25 m. , and the occurrence of discharge can be detected. On the other hand, when the distance between the discharge detection unit 1 and the discharge occurrence point is 50 m, it is set so that it is equal to or less than the second threshold and the occurrence of discharge cannot be detected. When the set value of the threshold value setting unit 13 is set to the third threshold value lower than the second threshold value, even when the distance between the discharge detection unit 1 and the discharge generation location is as far as 50 m, the third threshold value can be set. is greater than or equal to the threshold, and the occurrence of discharge can be detected. As described above, by having a plurality of threshold values and selecting one of them, the range for detecting the occurrence of discharge can be freely changed. As for the setting of the discharge generation point. It is not limited to 5m, 25m and 50m.

Thus, the range in which the occurrence of discharge can be detected changes depending on the setting of the threshold. Therefore, if the structure is such that the threshold value can be varied, the range in which the occurrence of discharge can be detected can be selected. For example, if it is desired to detect the occurrence of a discharge that has occurred at a relatively distant location, the threshold value should be set low. Conversely, if it is desired to detect only the occurrence of discharge occurring in a relatively close place, the threshold should be set higher. Since this can be done, as can be understood from FIG. 7, it is possible to avoid picking up noise caused by an electrical discharge accident that occurred in another building 81 .

In particular, if several thresholds are set in advance so that the range of the distance of the detectable discharge point can be specified, and the threshold can be selected, usability will be improved. Although three thresholds are set in the embodiment, the number of thresholds to be set may be less or more than that.

By the way, it is also assumed that the output momentarily exceeds the threshold for some reason. Therefore, as can be understood from FIG. 8, in the embodiment, control is performed so that it is determined that noise caused by discharge is output when the threshold is continuously exceeded for a predetermined period of time. This predetermined time may be a fixed value, or may be set to a desired value.

In the examples shown in FIGS. 9 to 11, the discharge detection unit 1 is provided with the target frequency changing means 14 . The target frequency changing means 14 is used to change the target frequency and is used to specify the target frequency. In the embodiment, the target frequency changing means 14 includes a target frequency operation section 15 and a target frequency setting section 16, and operates the target frequency operation section 15 provided on the surface of the housing 10 of the discharge detection unit 1. , the target frequency can be set and the determination conditions can be changed.

In the example shown in FIG. 11, the target frequency changing means 14 is used to change the target frequency indicated by the solid line in the initial state to the value indicated by the broken line. Depending on the installation location, the discharge detection unit 1 of this embodiment may be affected by other devices, or noise may be added to the measured value due to the influence of wireless communication. Therefore, it is preferable that the frequency be changed to a frequency that is free from the influence of other devices and the influence of noise. By the way, as can be understood from FIG. 11, the output fluctuates when the target frequency changes. Therefore, it is desirable to reset the threshold according to the target frequency. Therefore, for example, it is preferable to store graphs and tables in advance in the storage unit 25 so that a threshold suitable for the selected frequency can be derived. By doing so, it is possible to reset the threshold in conjunction with setting the frequency. In addition, in the embodiment, the storage unit 25 and the control unit are provided, and the control unit reads the information stored in the storage unit 25 and controls the threshold setting unit 11 to set the threshold based on the read information. With this configuration, it is possible to reduce the burden of adjusting the threshold value when the target frequency is changed.

In the example shown in FIG. 11, when the target frequency is ◯ Hz, the set value of threshold 1 is 80 mV, the set value of threshold 2 is 70 mV, and the set value of threshold 3 is 60 mV. When the frequency is ×Hz, the threshold 1 is set to 50 mV, the threshold 2 is set to 40 mV, and the threshold 3 is set to 30 mV. When the frequency is □ Hz, the set value of threshold 1 is 20 mV, the set value of threshold 2 is 10 mV, and the set value of threshold 3 is 5 mV.

The storage section 25 capable of storing such information is preferably provided in the discharge detection unit 1 as shown in FIG. In the example shown in FIG. 12, the discharge detection unit 1 is provided with storage input means 71 used to input information to the storage 25 . By using this storage unit input means 71, the threshold value can be newly set. For example, in the initial settings, when the target frequency is O Hz, the set value for threshold 1 is 80 mV, the set value for threshold 2 is 70 mV, and the set value for threshold 3 is 60 mV. As can be understood from the figure, for example, the set value of threshold 1 is set to 80 mV, the set value of threshold 2 is set to 50 mV, and the set value of threshold 3 is set to 30 mV, and these settings can be stored in the storage unit 25. can.

The storage unit 25 may store in advance the thickness and type of cables in association with graphs and tables. Also, it may be possible to store that a discharge accident has occurred. For example, if there is a record in the storage unit 25 that a discharge accident has occurred, the threshold can be set lower than the initial state.

When the discharge detection unit 1 determines that a discharge accident has occurred, a cutoff signal may be sent to the main breaker 31 or the like to cut off the breaker. In the example shown in FIG. 14, when the discharge detection unit 1 installed on the secondary side of the main breaker 31 detects a discharge accident, it sends a cutoff signal to the tripping device 32 of the main breaker 31 to turn off the main breaker 31. state.

Further, as can be understood from FIG. 15, the ground wire 51 is provided in the discharge detection unit 1, and when the discharge detection unit 1 determines that a discharge accident has occurred, a pseudo leakage current is supplied to turn off the breaker. You may make it cut off. Incidentally, as can be understood from FIG. 16, the CT 61 may be used to detect the discharge accident. In this case, the filter section 21 and CT 61 function as a detection section. Further, as can be understood from FIG. 17, a discharge accident may be detected by detecting a voltage using the voltage detection section 62 . In this case, the voltage detection section 62 and the filter section 21 function as a detection section.

Although the present invention has been described above using the embodiments as examples, the present invention is not limited to the above-described embodiments, and various aspects are possible.

1 discharge detection unit 10 housing 11 threshold value setting means 12 setting operation section 25 storage section

Claims (4)

A discharge detection unit used by being electrically connected to a distribution board provided in a building or a wiring line connected to the distribution board,
An output at a target frequency set to a specific frequency in a radiation noise frequency band is connected to the wiring path in order to detect discharge noise generated by a discharge accident occurring on the wiring path connected to the distribution board in the building. A detection unit that selects and detects using a filter unit;
target frequency changing means used to change the target frequency;
a threshold setting means used to set a threshold that serves as a criterion for determining the presence or absence of noise output;
with
A discharge detection unit in which the threshold can be selected from a plurality of preset options, and a distance to a discharge occurrence point that can be detected by the discharge detection unit can be changed by selecting the threshold. 2. The discharge detection unit according to claim 1, wherein a setting operation section operated when setting a threshold value serving as a criterion for determining presence or absence of noise output can be operated from the outside of the housing of the discharge detection unit. 3. The discharge according to claim 1 or 2 , further comprising a storage unit and a control unit, wherein the control unit reads information stored in the storage unit and controls the threshold setting means to set a threshold based on the read information. detection unit. 4. The discharge detection unit according to any one of claims 1 to 3 , further comprising time setting means for setting a time that serves as a criterion for determining the presence or absence of noise output.

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