Discharge Detection System

Abstract

To reduce the burden of wiring work when a discharge detection system is constructed.SOLUTION: A discharge detection system includes: a main circuit 10; a branch circuit 20 which is an earth leakage breaker; a discharge detection unit 30 having a discharge detection section 31 used for detecting a discharge event; and a master unit 40 that communicates with the discharge detection unit via a communication line 83. The master unit is connected to or integrally formed with a wiring 81 connected to a secondary side of the main circuit and is connected to or integrally formed with a communication line connected to the discharge detection unit. The discharge detection unit includes an opening / closing section 32 that connects a communication line connected to or integrally formed with the wiring connected to the secondary side of the main circuit and an electric circuit of the branch circuit. The opening / closing section can close by communication with the master unit. The wiring connected to the secondary side of the main circuit, connected to or integrally formed with the communication line is connected to a phase different from a phase input to the branch circuit.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electric discharge detection system. [Background technology]

[0002] As described in Patent Document 1, it is known that a circuit is provided with a plurality of discharge detection units capable of detecting the occurrence of a discharge event, detection information from each discharge detection unit is collected and judged in a calculation unit, and when the occurrence of a discharge event is identified, a signal is sent to the breaker or main circuit of the identified circuit to cut it off. Also, as described in Patent Document 2, it is known that a ground fault circuit interrupter is operated by passing a pseudo earth leakage current through the circuit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-122669 [Patent Document 2] Japanese Patent Publication No. 56-48022

[0004] However, when a pseudo-earth leakage current is applied, it is necessary to connect a bypass circuit to the primary side of the earth leakage current breaker. As a result, as the number of circuits increases, there are problems such as the increase in the work required to connect the bypass circuits. Also, when the breaker is a plug-in type, there is the problem that it is difficult to route the bypass circuit. Summary of the Invention [Problem to be solved by the invention]

[0005] The inventors of the present invention have made extensive research into this point and have attempted to solve it.The problem that the present invention aims to solve is to reduce the burden of wiring work when constructing an electric discharge detection system. [Means for solving the problem]

[0006] In order to solve the above problem, a discharge detection system is provided which includes a main circuit, a branch circuit which is a leakage current breaker, a discharge detection unit having a discharge detection section used to detect discharge events, and a parent unit which communicates with the discharge detection unit via a communication line, wherein the parent unit is connected to or integrally formed with wiring connected to the secondary side of the main circuit, and is connected to or integrally formed with a communication line connected to the discharge detection unit, the discharge detection unit has an opening / closing section which connects the communication line connected to or integrated with the wiring connected to the secondary side of the main circuit and the electrical circuit of the branch circuit, the opening / closing section being capable of being closed by communication with the parent unit, and the wiring connected to the secondary side of the main circuit connected to or integrated with the communication line is connected to a phase different from the phase input to the branch circuit.

[0007] It is also preferable that the discharge detection unit is provided with a limiting resistor that acts as a resistance when current is passed through a communication line connected to or integrated with the wiring that is connected from the discharge detection unit to the secondary side of the main circuit.

[0008] It is also preferable that the master unit be provided with a limiting resistor that acts as a resistance when current is passed through a communication line that is connected to or integrated with the wiring that is connected from the discharge detection unit to the secondary side of the main circuit.

[0009] Furthermore, when detection results that are determined to be a discharge event are obtained from a plurality of discharge detection units, it is preferable to configure the master unit to shift the timing of output to each discharge detection unit.

[0010] Furthermore, it is preferable that the parent unit be configured to send a signal to operate the opening and closing part of one discharge detection unit, and then send a signal to the discharge detection unit again, and if it determines that communication with the discharge detection unit is not possible as a result, send a signal to operate the opening and closing part of the next discharge detection unit.

[0011] The discharge detection system also includes a main circuit, a branch circuit that is a leakage current breaker, and a discharge detection unit that has a discharge detection section used to detect discharge events, and the secondary side of the main circuit is provided with wiring that is connected to a phase that inputs to the branch circuit and a phase different from the phase, and the discharge detection unit has a switching section that connects the wiring to the electrical circuit of the branch circuit and is capable of closing the switching section when a discharge is detected. [Effects of the Invention]

[0012] The present invention makes it possible to reduce the burden of wiring work when constructing a discharge detection system. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a conceptual diagram of a distribution board equipped with a discharge detection system. [Figure 2] FIG. 10 is a diagram illustrating an example of the relationship between a parent unit and the periphery of some branch circuits. [Figure 3] 3 is a diagram showing an example in which the opening / closing section is closed in the configuration example shown in FIG. 2. FIG. [Figure 4] 3 is a diagram showing an example of a current flow in the state shown in FIG. 2. FIG. [Figure 5] 4 is a diagram showing an example of a current flow in the state shown in FIG. 3. [Figure 6] FIG. 10 is a diagram showing an example in which a current is passed through the L2 phase via a communication line. [Figure 7] FIG. 10 is a diagram showing an example in which a limiting resistor is provided in a parent unit. [Figure 8] FIG. 10 is a diagram showing the flow from when the discharge detection unit detects noise corresponding to a discharge event to when the open / close switch of the branch circuit is opened. [Figure 9] FIG. 10 is a diagram showing an example of a flow of determining that a branch circuit has been cut off and then moving to cut off the next branch circuit. [Figure 10] FIG. 10 is a diagram showing an example of a system capable of generating a pseudo electric leakage current when determining whether an electric discharge is detected by an electric discharge detection unit. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the invention is described below. As can be seen from FIGS. 1 to 5 , the discharge detection system of this embodiment includes a main circuit 10, a branch circuit 20 that is an earth leakage breaker, a discharge detection unit 30 having a discharge detection section 31 used to detect a discharge event, and a parent unit 40 that communicates with the discharge detection unit 30 via a communication line 83. The parent unit 40 of this discharge detection system is connected to or integrally formed with a wiring 81 connected to the secondary side of the main circuit 10, and is also connected to or integrally formed with a communication line 83 connected to the discharge detection unit 30. The discharge detection unit 30 also includes a switching unit 32 that connects the communication line 83 connected to or integrally formed with the wiring 81 connected to the secondary side of the main circuit 10 to an electrical circuit of the branch circuit 20. The switching unit 32 can close the switching unit 32 by communicating with the parent unit 40, and the communication line 83 connected to or integrally formed with the wiring 81 connected to the secondary side of the main circuit 10 is connected to a phase different from the phase input to the branch circuit 20. This makes it possible to reduce the burden of wiring work when constructing a discharge detection system.

[0015] The discharge detection system shown in FIG. 1 is constructed in a distribution board D, and applies a pseudo-earth leakage current to a branch circuit 20 provided on the secondary side of a main circuit 10 so that the branch circuit 20 is shut off when a discharge event occurs. Note that all of the branch circuits 20 shown in FIG. 1 are earth leakage breakers that can detect pseudo-earth leakage currents. It is preferable that the main circuit 10 also be an earth leakage breaker, but a circuit breaker without earth leakage detection function may also be used. The branch circuit 20 is connected to one of the voltage phases provided on the secondary side of the main circuit 10.

[0016] 1 also includes discharge detection units 30 in one-to-one correspondence with the branch circuits 20. These discharge detection units 30 are capable of detecting noise output superimposed on the voltage or current of the wiring formed in the branch circuit 20. Furthermore, these discharge detection units 30 are capable of sending signals to the parent unit 40 via a communication line 83. The communication line 83 formed in the parent unit 40 consists of two lines, one for a voltage phase and one for an N phase, and one of these communication lines 83 is connected to the N phase.

[0017] The master unit 40 is used when collecting noise information from the discharge detection unit 30 and when identifying the location of a discharge event. For this reason, the master unit 40 of the embodiment includes a calculation unit 41 that can perform calculations to derive the location of a discharge event from the noise information of the discharge detection unit 30 collected via the communication line 83. The calculation unit 41 of the embodiment can also output a signal to open or close the opening / closing unit 32 of the discharge detection unit 30 that has identified the location of a discharge occurrence.

[0018] Furthermore, the base unit 40 of the embodiment is equipped with an external communication unit 42 that can output information to an external device based on the calculation results of the calculation unit 41. It is also equipped with a display unit 43 that can display the location of the discharge. Therefore, when the base unit 40 determines that a discharge event has occurred, it can notify those around it.

[0019] The parent unit 40 is not only connected to the discharge detection unit 30, but also to a phase provided on the secondary side of the main circuit 10. In the example shown in FIG. 2, it is connected to the L1 phase, which is the same phase input to the branch circuit 20, and to the N phase, which is different from the phase input to the branch circuit 20.

[0020] The reason why the parent unit 40 is connected to the same phase as the phase input to the branch circuit 20 is so that power can be supplied to the parent unit 40. If power can be supplied to the parent unit 40 from another location, it is not necessary to connect it to this phase.

[0021] The reason why the parent unit 40 is connected to a phase different from the phase input to the branch circuit 20 is so that when a discharge event is detected, the parent unit 40 can pass current through a phase different from the phase input to the branch circuit 20 via the communication line 83 used to exchange information between the discharge detection unit 30 and the parent unit 40.

[0022] In the example shown in Fig. 2, the phase input from the parent unit 40 to the branch circuit 20 is the L1 phase, and phases other than the L1 phase include the L2 phase and the N phase. In the example shown in Fig. 2, the N phase is the phase through which current can flow via the communication line 83 when a discharge event is detected. In the example shown in Fig. 2, the parent unit 40 and the phase are connected on the primary side of the point where the branch circuit 20 is connected.

[0023] Although multiple electric discharge detection units 30 can be connected to the communication line 83 that connects the electric discharge detection units 30 and the parent unit 40, it is not necessary to connect the parent unit 40 to the phases with a corresponding number of wires 81. Connecting the parent unit 40 to the phase at one point makes it possible to ensure a path for current to flow from multiple electric discharge detection units 30 to the phase. This reduces the effort required for wiring work and the space required for routing the wires 81. Note that even when using a phase that is difficult to connect multiple wires to, such as a bus bar that connects a plug-in type branch circuit 20, it is relatively easy to build an electric discharge detection system.

[0024] The discharge detection unit 30 of the embodiment includes a discharge detection section 31 that detects noise superimposed on the voltage and current of the electrical circuit when a discharge event occurs, a communication circuit 34 that outputs a signal to the parent unit 40 to transmit information obtained by the discharge detection section 31 to the parent unit 40, and an opening / closing section 32 that can change from an open state to a closed state based on the signal received from the parent unit 40, thereby changing from an electrically disconnected state to an electrically connected state for a phase different from the phase that the parent unit 40 inputs to the branch circuit 20 (see Figures 2 and 3).

[0025] As can be seen from Figure 4, before the opening / closing section 32 is closed, the current flowing from a phase (L1 phase in Figure 4) into the branch circuit 20 passes through the discharge detection section 31 of the discharge detection unit 30, is returned to the branch circuit 20, and then flows into the N phase.

[0026] On the other hand, as can be seen from Figure 5, after the opening / closing unit 32 is closed, the current flowing from the phase (L1 phase in Figure 5) into the branch circuit 20 also flows to the N phase via the communication line 83 in addition to the flow shown in Figure 4.

[0027] In the explanation so far, when a discharge event occurs, a current is caused to flow to the N phase via the communication line 83, but a current may be caused to flow to another phase. In the example shown in Fig. 6, when a discharge event occurs, a current is caused to flow to the L2 phase via the communication line 83.

[0028] In this way, when a portion of the current input to the discharge detection unit 30 via the branch circuit 20 is prevented from being returned to the branch circuit 20, the ZCT 21 provided in the branch circuit 20 detects that a leakage current has occurred. As a result of this detection, the open / close switch 22 provided in the branch circuit 20 operates to open, and the supply of current to the secondary side of the branch circuit 20 is stopped.

[0029] The earth leakage breaker constituting the branch circuit 20 or the like has a set sensitivity current value for detecting an earth leakage current. In other words, an earth leakage current can be detected when the current value detected by the ZCT 21 is within a predetermined range. In this embodiment, a limiting resistor 33 is provided so that the earth leakage breaker can detect when a pseudo earth leakage current flows in a phase. This limiting resistor 33 acts as a resistance when current flows from the discharge detection unit 30 to the communication line 83 connected to or integrated with the wiring 81 connected to the secondary side of the main circuit 10, and adjusts the current value when the switching unit 32 is closed to flow a pseudo earth leakage current in the phase via the communication line 83.

[0030] More specifically, the wiring 81 of the parent unit 40 in this embodiment is formed from two wires connected to the L1 phase and the N phase, and is integrated by connecting the N-phase wiring 81 to the N phase of the communication line 83. Although the description of this embodiment has been given using a single-phase three-wire system, a three-phase three-wire system or a three-phase four-wire system may also be used, and it is sufficient that the circuit is formed so that current flows in a phase different from the input to the branch circuit 20, that is, when it is determined that a discharge event has occurred, a process is performed to close the switch 32 of the discharge detection unit 30, thereby generating a difference in the current flowing between the input and output of the branch circuit 20, thereby enabling the ZCT 21 to detect a ground fault.

[0031] 2, a limiting resistor 33 is provided on the secondary side of the switching unit 32. Providing the limiting resistor 33 in the discharge detection unit 30 makes it easy to set the limiting resistor 33 to match the corresponding branch circuit 20. Furthermore, the minimum resistance value required for the limiting resistor 33 can be reduced.

[0032] The location where the limiting resistor 33 is provided does not have to be limited to the discharge detection unit 30. For example, as can be seen from Fig. 7, the limiting resistor 33 may be provided in the parent unit 40. In this case, it is not necessary to provide the limiting resistor 33 in each discharge detection unit 30.

[0033] When the parent unit 40 is provided with a limiting resistor 33, it is possible to "form a limiting resistor 33 with a resistance value equal to the pseudo leakage current multiplied by the number of interrupting circuits," or to "form a limiting resistor 33 for one circuit." If a resistance value corresponding to multiple open circuits is used, as in the former, it is possible to interrupt multiple circuits at once. Even in the latter case, this can be handled by sequentially interrupting multiple discharge detection units 30. Because this is possible, when detection results determined to be a discharge event are obtained from multiple discharge detection units 30, it is preferable to stagger the timing of the output from the parent unit 40 to each discharge detection unit 30.

[0034] An example of the operation of the discharge detection system will now be described with reference to the diagram shown in Fig. 8. When discharge detection unit 30 installed on the secondary side of branch circuit 20 detects noise output superimposed on the voltage or current of wiring 81 formed in branch circuit 20, information is sent from communication circuit 34 provided in discharge detection unit 30 to parent unit 40. When parent unit 40 determines from the information that a discharge event has occurred, a signal is output from parent unit 40 to close opening / closing section 32 of discharge detection unit 30.

[0035] When the switching unit 32 is closed, part of the current input to the branch circuit 20 flows back to the primary side of the branch breaker through the communication line 83 and the wiring 81. When the ZCT 21 provided in the branch circuit 20 detects that the magnitude of the outgoing current is different from the magnitude of the returning current, it opens the switching switch 22 of the branch circuit 20. When the switching switch 22 is opened, no current flows to the secondary side of the branch circuit 20.

[0036] Next, a control example when a discharge event is suspected to have occurred in multiple circuits will be described with reference to the diagram shown in Fig. 9. In summary, the calculation unit 41 of the parent unit 40 sends information to each discharge detection unit 30 at intervals, thereby successively shutting off each branch circuit 20. The calculation unit 41 has a communication circuit 41a that communicates with the communication circuit 34 provided in the discharge detection unit 30 via a communication line, and communication line 83 communicates with each of the communication circuits 34, 41a.

[0037] When information is sent from multiple discharge detection units 30 to the master unit 40, and the master unit 40 determines that a discharge event has occurred based on the multiple pieces of information, the master unit 40 sends a signal to one discharge detection unit 30 to close the opening / closing section 32. After sending the signal to one discharge detection unit 30, the master unit 40 sends the signal again to the same discharge detection unit 30.

[0038] If the instruction from the previous signal is carried out and the open / close switch 22 of the branch circuit 20 is in an open state, no current will flow to the discharge detection unit 30, so the discharge detection unit 30 will not be able to respond to the signal sent again. If it detects that there is no response from the discharge detection unit 30 to the parent unit 40 (no current is flowing), it will send a signal to other discharge detection units 30 that need to send a signal to close the open / close section 32. By repeating this process, multiple circuits are cut off. Controlling in this way makes it possible to reduce congestion on communication lines.

[0039] To make this possible, it is preferable that the parent unit 40, after sending a signal to operate the opening / closing section 32 of one discharge detection unit 30, send a signal to the discharge detection unit 30 again, and if it determines that communication with the discharge detection unit 30 is not possible as a result, send a signal to operate the opening / closing section 32 of the next discharge detection unit 30.

[0040] Up to this point, a circuit for dummy earth leakage current has been created using a signal line connected to the parent unit 40, but in cases where the discharge detection unit 30 itself detects whether a discharge event has occurred, the parent unit 40 is not necessarily required. In such cases, a circuit for dummy earth leakage current may be created without using a signal line connected to the parent unit 40. For example, in the example shown in Figure 10, the wiring 85 connected to the secondary side of the discharge detection unit 30 is simply connected to a phase different from the phase input to the branch circuit 20.

[0041] In this way, the discharge detection system comprises a main circuit 10, a branch circuit 20 which is a leakage current breaker, and a discharge detection unit 30 which has a discharge detection section 31 used to detect discharge events, and the secondary side of the main circuit 10 is provided with a phase input to the branch circuit 20 and a phase different from said phase, and is provided with wiring 85 connected to a phase different from the phase input to the branch circuit 20, and the discharge detection unit 30 is provided with a switching section 32 which connects said wiring 81 to the electrical circuit of the branch circuit 20, and is capable of closing the switching section 32 when a discharge is detected, so that the burden of wiring work when constructing the discharge detection system can be reduced.

[0042] In this case, it is preferable to provide the discharge detection unit 30 with a limiting resistor 33. In addition, in this case, since the communication line 83 is not used, the type of wiring 85 can be freely selected. However, it is preferable that this wiring 85 has a structure that allows easy connection to multiple discharge detection units 30.

[0043] Although the present invention has been described above using the embodiments as examples, the present invention is not limited to the above embodiments and can be embodied in various forms. For example, It is also possible. [Explanation of symbols]

[0044] 10 Main circuit 20 Branch Circuit 30 Discharge detection unit 31 Discharge detection unit 32 Opening and closing section 33 Limiting resistor 40 Base unit 81 Wiring 83 Communication Line

Claims

1. A discharge detection system including a main circuit, a branch circuit that is an earth leakage breaker, a discharge detection unit having a discharge detection section used to detect a discharge event, and a parent unit that communicates with the discharge detection unit via a communication line, The parent unit is connected to a wiring connected to the secondary side of the main circuit and to a communication line connected to the discharge detection unit, The discharge detection unit includes a switching unit that connects a communication line connected to a wiring connected to the secondary side of the main circuit with an electric circuit of the branch circuit; The opening / closing unit can be closed by communication with the parent unit, A discharge detection system in which the wiring connected to the secondary side of the main circuit connected to the communication line is connected to a phase different from the phase input to the branch circuit.

2. 2. The discharge detection system according to claim 1, wherein the discharge detection unit is provided with a limiting resistor that acts as a resistance when current is passed through a communication line connected to a wiring connected from the discharge detection unit to the secondary side of the main circuit.

3. 2. The electric discharge detection system according to claim 1, wherein the master unit includes a limiting resistor that acts as a resistance when current is passed through a communication line connected to a wiring connected from the electric discharge detection unit to the secondary side of the main circuit.

4. 4. The discharge detection system according to claim 1, wherein when detection results determined to be a discharge event are obtained from a plurality of discharge detection units, the timing of output from the parent unit to each discharge detection unit is shifted.

5. The discharge detection system described in claim 4, wherein the parent unit sends a signal to operate the opening / closing part of one discharge detection unit, and then sends a signal to the discharge detection unit again, and if it determines that communication with the discharge detection unit is not possible as a result, it sends a signal to operate the opening / closing part of the next discharge detection unit.

6. A discharge detection system including a main circuit, a branch circuit that is an earth leakage breaker, and a discharge detection unit having a discharge detection section used to detect a discharge event, a wiring connected to a phase input to the branch circuit and a phase different from the phase input to the branch circuit on the secondary side of the main circuit; The discharge detection unit includes an opening / closing part that connects the wiring to an electric circuit of a branch circuit, A discharge detection system that is capable of closing a switching unit when a discharge is detected.

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