Determination device, automatic reclosing device, circuit breaker with automatic reclosing function and program

Abstract

To provide a determination device capable of improving determination accuracy for determining whether or not a factor which brings a breaker into a trip state is overcurrent, an automatic resupply device, a breaker with automatic resupply function and a program.SOLUTION: A determination device 4 comprises: a current detection unit 41 which detects whether or not a current value to be electrified to a breaker 2 exceeds a predetermined threshold; a handle position detection unit 42 which detects whether or not a handle 23 of the breaker 2 is in an open state; and a determination unit 44 for determining that a cause which brings the breaker 2 into a trip state is overcurrent. The current detection unit 41 is configured to hold a current detection signal indicating that the current value exceeds the predetermined threshold for a predetermined time after the current value exceeds the predetermined threshold. The determination unit 44 determines whether or not the factor which brings the breaker 2 into the trip state is overcurrent based on the current detection signal and a handle opening / closing signal indicating the detection that the handle 23 of the breaker 2 is in the open state.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a determination device, an automatic reclosing device, a circuit breaker with an automatic reclosing function, and a program. [Background technology]

[0002] Circuit breakers are safety devices that detect excessive current flowing in an electric circuit and automatically cut off the load from the circuit, and are installed in various facilities. For example, circuit breakers installed in facilities where there is no on-site manager use an automatic reclosing device that can automatically reset the breaker handle if the circuit breaker is tripped due to transient noise or the like (see Patent Document 1).

[0003] In an automatic re-closing device such as that described in Patent Document 1, when a circuit breaker is in an interrupted state (tripped state), if the cause of the tripped state is not an overcurrent, the breaker handle is operated and controlled to release the tripped state, i.e., to re-close the circuit breaker. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-032874 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the conventional automatic restart device has room for improvement in the accuracy of determining whether or not the cause of the circuit breaker tripping is an overcurrent.

[0006] Therefore, an object of the present invention is to provide a determination device, an automatic restart device, a circuit breaker with an automatic restart function, and a program that can improve the accuracy of determining whether an overcurrent is the cause of a circuit breaker tripping. [Means for solving the problem]

[0007] In order to achieve the above object, the determination device of the present invention comprises: a current detection unit that detects whether or not a value of a current flowing through the circuit breaker exceeds a predetermined threshold; a handle detection unit that detects whether a handle of the circuit breaker is in an open state; a determination unit that determines whether the cause of the circuit breaker being in a tripped state is an overcurrent; Equipped with the current detection unit is configured to hold a first detection signal indicating that the current value has exceeded the predetermined threshold for a predetermined time after the current value has exceeded the predetermined threshold; The determination unit determines whether an overcurrent is the cause of the circuit breaker tripping based on the first detection signal and a second detection signal indicating that the handle of the circuit breaker has been detected to be in the open state.

[0008] The determination device of the present invention also includes: a current detection unit that detects whether or not a value of a current flowing through the circuit breaker exceeds a predetermined threshold; a voltage detection unit that detects the presence or absence of a voltage on the secondary side of the circuit breaker; a determination unit that determines whether the cause of the circuit breaker being in a tripped state is an overcurrent; Equipped with the current detection unit is configured to hold a first detection signal indicating that the current value has exceeded the predetermined threshold for a predetermined time after the current value has exceeded the predetermined threshold; The determination unit determines whether an overcurrent is the cause of the circuit breaker tripping, based on the first detection signal and a third detection signal indicating that no voltage is detected on the secondary side of the circuit breaker.

[0009] The determination device of the present invention also includes: a current detection unit that detects whether or not a value of a current flowing through the circuit breaker exceeds a predetermined threshold; a handle detection unit that detects whether a handle of the circuit breaker is in an open state; a voltage detection unit that detects the presence or absence of a voltage on the secondary side of the circuit breaker; a determination unit that determines whether the cause of the circuit breaker being in a tripped state is an overcurrent; Equipped with the current detection unit is configured to hold a first detection signal indicating that the current value has exceeded the predetermined threshold for a predetermined time after the current value has exceeded the predetermined threshold, The determination unit determines whether an overcurrent is the cause of the circuit breaker reaching a tripped state based on the first detection signal and at least one of a second detection signal indicating that the handle of the circuit breaker has been detected to be in an open state and a third detection signal indicating that no voltage has been detected on the secondary side of the circuit breaker.

[0010] The automatic re-insertion device of the present invention is The determination device; a handle holding portion attached to a handle of the circuit breaker; a control unit that controls the operation of the handle holding unit based on the determination result of the determination device; Equipped with.

[0011] Furthermore, the circuit breaker with automatic restart function of the present invention is The automatic reclosing device and the circuit breaker are provided.

[0012] The program of the present invention also includes: A program that causes a determination device including a current detection unit, a handle detection unit, and a determination unit to execute the following process: causing the current detection unit to detect whether a value of a current flowing through the circuit breaker exceeds a predetermined threshold, and to hold a first detection signal indicating that the current value has exceeded the predetermined threshold for a predetermined time after the current value has exceeded the predetermined threshold; causing the handle detection unit to detect whether the handle of the circuit breaker is in an open state; a step of causing the determination unit to determine whether or not the cause of the circuit breaker reaching a trip state is an overcurrent, based on the first detection signal and a second detection signal indicating that the handle of the circuit breaker has been detected to be in an open state; Execute a process including:

[0013] The program of the present invention also includes: A program for causing a determination device including a current detection unit, a voltage detection unit, and a determination unit to execute the following process: causing the current detection unit to detect whether a value of a current flowing through the circuit breaker exceeds a predetermined threshold, and to hold a first detection signal indicating that the current value has exceeded the predetermined threshold for a predetermined time after the current value has exceeded the predetermined threshold; causing the voltage detection unit to detect the presence or absence of voltage on the secondary side of the circuit breaker; a step of causing the determination unit to determine whether or not the cause of the circuit breaker reaching a trip state is an overcurrent, based on the first detection signal and a third detection signal indicating that a voltage on the secondary side of the circuit breaker is not detected; Execute a process including:

[0014] The program of the present invention also includes: A program that causes a determination device including a current detection unit, a handle detection unit, a voltage detection unit, and a determination unit to execute the following process: causing the current detection unit to detect whether a value of a current flowing through the circuit breaker exceeds a predetermined threshold, and to hold a first detection signal indicating that the current value has exceeded the predetermined threshold for a predetermined time after the current value has exceeded the predetermined threshold; causing the handle detection unit to detect whether the handle of the circuit breaker is in an open state; causing the voltage detection unit to detect the presence or absence of voltage on the secondary side of the circuit breaker; a step of causing the determination unit to determine whether or not the cause of the circuit breaker reaching a trip state is an overcurrent, based on the first detection signal and at least one of a second detection signal indicating that a handle of the circuit breaker has been detected to be in an open state and a third detection signal indicating that a voltage on the secondary side of the circuit breaker has not been detected; Execute a process including: [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a determination device, an automatic restart device, a circuit breaker with an automatic restart function, and a program that can improve the accuracy of determining whether or not an overcurrent has caused a circuit breaker to trip. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a configuration diagram illustrating an example of a circuit breaker with an automatic reclosing function according to an embodiment of the present invention. [Figure 2] FIG. 2 is a functional block diagram of a circuit breaker with an automatic reclosing function. [Figure 3] 10 is a flowchart for determining whether an overcurrent has caused the trip state based on a current detection signal and a handle open / close signal. [Figure 4] 10 is a flowchart for determining whether the cause of the trip state is an overcurrent based on a current detection signal and a voltage non-detection signal. [Figure 5] 10 is a flowchart for determining whether an overcurrent is the cause of the trip state based on a current detection signal, a handle open / close signal, and a voltage non-detection signal. [Figure 6] 10(a) to 10(e) are time charts showing a first determination example when a current detection signal is continuously output for a predetermined time. [Figure 7] 10(a) to 10(e) are time charts showing a second determination example when a current detection signal is continuously output for a predetermined time. [Figure 8] 10(a) to 10(e) are time charts showing examples of determinations when a current detection signal is not output. [Figure 9] 10(a) to 10(e) are time charts showing a comparison and determination example in which the current detection signal is not continuously output. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a determination device, an automatic reclosing device, a circuit breaker with an automatic reclosing function, and a program therefor according to the present invention will be described with reference to the drawings.

[0018] (First embodiment) Fig. 1 is a configuration diagram of a circuit breaker 1 with an automatic restart function according to this embodiment. As shown in Fig. 1, the circuit breaker 1 with an automatic restart function includes a circuit breaker 2 and an automatic restart device 3. The circuit breaker 1 with an automatic restart function is a circuit breaker that detects an overcurrent, overvoltage, earth leakage, etc. that occurs in the circuit breaker 2, and is capable of automatically restarting the circuit breaker 2 that has tripped and is in the OFF state based on the detection results. In this embodiment, a single-phase three-wire circuit breaker will be described, in which voltage lines L1 and L2 are wired at both ends and a neutral line N is wired in the center.

[0019] The circuit breaker 2 has a power supply side (primary side) terminal block 21, a load side (secondary side) terminal block 22, and a handle 23 disposed therebetween. The power supply side terminal block 21 is provided with power supply side terminals 21a, 21b, and 21c. The load side terminal block 22 is provided with load side terminals 22a, 22b, and 22c. A voltage line L1, a neutral line N, and a voltage line L2 are connected in corresponding order to the power supply side terminals 21a, 21b, and 21c and the load side terminals 22a, 22b, and 22c. Current sensors 24a and 24b are connected to the voltage lines L1 and L2 connected to the load side terminals 22a and 22c, respectively, for measuring the currents flowing through the voltage lines L1 and L2.

[0020] The handle 23 is configured to be changeable between an open state and a closed state. The open state of the handle 23 refers to a state in which the power supply contacts on the power supply side and the load contacts on the load side in the circuit breaker 2 are not in contact with each other, and there is no electrical continuity between the voltage lines L1, L2, and the neutral line N on the power supply side and the voltage lines L1, L2, and the neutral line N on the load side. The closed state of the handle 23 refers to a state in which the power supply contacts on the power supply side and the load contacts on the load side in the circuit breaker 2 are in contact with each other, and there is electrical continuity between the voltage lines L1, L2, and the neutral line N on the power supply side and the voltage lines L1, L2, and the neutral line N on the load side. The handle 23 is configured to be movable, for example, in the vertical direction in FIG. 1 . For example, moving the handle 23 upward turns the circuit breaker 2 on, and moving it downward turns the circuit breaker 2 off.

[0021] The circuit breaker 2 is configured so that, when a current exceeding a predetermined threshold continues to flow through the load-side voltage lines L1, L2 or the neutral line N for a predetermined period of time, the trip coil (not shown) trips, causing the power contacts on the power supply side and the load contacts on the load side to be in a non-contact state. The circuit breaker 2 is configured so that, when the power contacts on the power supply side and the load contacts on the load side are in a non-contact state, the power supply side voltage lines L1, L2 and the neutral line N and the load side voltage lines L1, L2 and the neutral line N are in a non-conductive state, causing the circuit breaker to trip. The predetermined time is set so that it operates more quickly as the current increases. For example, the predetermined time is set to be short for large currents such as short-circuit currents, longer for currents of a level such as inrush currents at switch-on, and even longer for currents that exceed the predetermined threshold due to heavy use of load equipment.

[0022] The automatic reclosing device 3 has a handle holding unit 31 and a drive unit 51 (described later in FIG. 2) that drives the handle holding unit 31. The handle holding unit 31 is attached so as to hold the handle 23 of the circuit breaker 2. The handle holding unit 31 is driven by the drive unit 51 and is configured to be movable, for example, in the vertical direction indicated by arrow A in FIG. 1. For example, the handle holding unit 31 moves from bottom to top, thereby moving the held handle 23 from bottom to top and changing it from an open state to a closed state. In this way, the handle holding unit 31 can turn on the circuit breaker 2 that has tripped and become in the off state.

[0023] FIG. 2 is a functional block diagram of the circuit breaker 1 with automatic restart function. 2, the automatic re-insertion device 3 has a determination device 4, a handle holding unit 31, a handle control unit 32, a display unit 33, a notification unit 34, a memory unit 35, and a power supply unit 36. The determination device 4 has a current detection unit 41, a handle position detection unit 42 (an example of a handle detection unit), a voltage detection unit 43, and a determination unit 44. The handle position detection unit 42 is included in the handle control unit 32.

[0024] The determination device 4 is a device that determines whether the circuit breaker 2 is in a tripped state, and, if the circuit breaker 2 is in a tripped state, determines whether the cause of the tripped state is an overcurrent. The current detection unit 41, the handle position detection unit 42, and the voltage detection unit 43 of the determination device 4 are each connected to a determination unit 44 so as to be able to communicate with each other.

[0025] The current detection unit 41 is connected to the current sensors 24a and 24b. The current detection unit 41 receives the current values ​​measured by the current sensors 24a and 24b. Based on the currents measured by the current sensors 24a and 24b, the current detection unit 41 detects whether the value of the current flowing through the load-side voltage lines L1 and L2, i.e., the value of the current flowing through the circuit breaker 2, exceeds a predetermined threshold. When the current detection unit 41 detects that the value of the current flowing through the circuit breaker 2 exceeds the predetermined threshold, it outputs a current detection signal (an example of a first detection signal) indicating that the current value has exceeded the predetermined threshold. The current detection unit 41 is configured to continuously output the current detection signal for a predetermined period of time (e.g., one second).

[0026] The handle position detection unit 42 is connected to the handle holding unit 31. The handle position detection unit 42 detects the mechanical position of the handle holding unit 31 (whether it is located on the upper side or the lower side). The handle position detection unit 42 recognizes the position of the handle 23 of the circuit breaker 2 based on the detected position of the handle holding unit 31, and detects whether the handle 23 is in the open state or the closed state. When the handle position detection unit 42 detects that the handle 23 is in the open state, it outputs a handle open / closed signal (an example of a second detection signal) indicating that it has detected that the handle 23 is in the open state. The handle open / closed signal output from the handle position detection unit 42 is input to the determination unit 44.

[0027] The voltage detection unit 43 is connected to load-side contacts (e.g., load-side contacts 122a, 122b, and 122c) on the load side of the circuit breaker 2. In the example shown in the figure, the voltage detection unit 43 is connected to the load-side terminal 22a, which is electrically connected to the load-side contact 122a, and the load-side terminal 22c, which is electrically connected to the load-side contact 122c. The voltage detection unit 43 detects whether or not there is a voltage on the secondary side of the circuit breaker 2, i.e., whether or not there is a voltage between the load-side contact 122a and the load-side contact 122c. When the voltage detection unit 43 detects that there is no voltage on the secondary side of the circuit breaker 2, i.e., that the load-side contact 122a and the load-side contact 122c are not electrically connected to the power-supply-side contact 121a and the power-supply-side contact 121c, the voltage detection unit 43 outputs a voltage non-detection signal (an example of a third detection signal) indicating that no voltage is detected on the secondary side of the circuit breaker 2. The voltage non-detection signal output from the voltage detection unit 43 is input to the determination unit 44.

[0028] When the circuit breaker 2 reaches a tripped state, the determination unit 44 determines whether the cause of the tripped state is an overcurrent. For example, the determination unit 44 determines whether the cause of the tripped state of the circuit breaker 2 is an overcurrent based on a current detection signal from the current detection unit 41 indicating that the value of the current flowing in the load-side voltage lines L1, L2, i.e., the value of the current flowing through the circuit breaker 2, has exceeded a predetermined threshold, and a handle open / close signal from the handle position detection unit 42 indicating that the handle 23 has been detected as being in the open position.

[0029] The determination unit 44 may also determine whether or not an overcurrent has caused the circuit breaker 2 to trip based on the current detection signal and the voltage undetected signal. The determination unit 44 may also determine whether or not an overcurrent has caused the circuit breaker 2 to trip based on the current detection signal, the handle open / close signal, and the voltage undetected signal.

[0030] The handle control unit 32 has a handle position detection unit 42 and a drive unit 51 that drives the handle holding unit 31. The handle control unit 32 controls the drive unit 51 to drive the handle holding unit 31. The handle control unit 32 controls the drive unit 51 based on the determination result of the determination device 4. For example, when the handle control unit 32 determines that the circuit breaker 2 has been turned off due to a temporary overcurrent such as noise, the handle control unit 32 moves the handle holding unit 31 from the lower side to the upper side, thereby changing the handle 23 from the open state to the closed state and restarting the circuit breaker 2.

[0031] The display unit 33 is configured with, for example, an LED (light emitting diode) numeric display. The display unit 33 is connected to the determination unit 44, and displays the operating state (normal operating state, tripped state, etc.) of the circuit breaker 1 with automatic reclosing function, the number of reclosing times, etc., based on a display instruction signal from the determination unit 44.

[0032] The notification unit 34 is connected to the determination unit 44, and based on a notification instruction signal from the determination unit 44, notifies, for example, by an alarm sound, that the circuit breaker 1 with automatic restart function is in a tripped state due to an overcurrent. Note that the notification unit 34 may be provided as an external alarm buzzer rather than as a part of the configuration of the automatic restart device 3.

[0033] The storage unit 35 is communicably connected to the determination unit 44. The storage unit 35 stores a predetermined threshold value of the current value flowing through the circuit breaker 2, a specific predetermined time for the current detection signal output from the current detection unit 41, etc. The storage unit 35 also stores a plurality of programs that cooperate with the current detection unit 41, the handle position detection unit 42, the voltage detection unit 43, and the determination unit 44 to cause the determination device 4 to execute specific processes.

[0034] The power supply unit 36 ​​receives power from the power supply side of the circuit breaker 2 and supplies a predetermined voltage to each part of the automatic restart device 3.

[0035] Next, the operation of the circuit breaker 1 with automatic restart function will be described with reference to a specific example of determination by the determination device 4. FIG. 3 is a flowchart showing how the determination device 4 of the circuit breaker 1 determines whether the cause of the circuit breaker 2 entering a trip state is an overcurrent. Fig. 6 is a time chart showing a first determination example when the value of the current flowing through the circuit breaker 2 exceeds a predetermined threshold. In Fig. 6, (a) is a diagram showing a change in the value of the current flowing through the circuit breaker 2, (b) is a diagram showing a current detection signal output from the current detection unit 41, (c) is a diagram showing a handle open / close signal output from the handle position detection unit 42, (d) is a diagram showing a voltage undetection signal output from the voltage detection unit 43, and (e) is a diagram showing an abnormal trip determination signal output from the determination unit 44.

[0036] As shown in FIG. 3, the current detection unit 41 acquires the value of the current flowing through the voltage lines L1 and L2 (step S10). Next, the current detection unit 41 detects whether or not the value of the current flowing through the circuit breaker 2 exceeds a predetermined threshold value (step S11).

[0037] In step S11, if it is detected that the value of the current flowing through the circuit breaker 2 does not exceed the predetermined threshold value (NO in step S11), the current detection unit 41 returns to step S10 and repeats each process. In FIG. 6(a), when the current value is i1 before time t1, it is detected that the current value does not exceed the predetermined threshold value.

[0038] Furthermore, in step S11, if it is detected that the current value i1 flowing through the circuit breaker 2 exceeds the predetermined threshold value (YES in step S11), the current detection unit 41 outputs a current detection signal indicating that the current value has exceeded the predetermined threshold value to the judgment unit 44 for a predetermined time (e.g., 1 second) as shown in (b) of Figure 6 (step S12).

[0039] Next, the determination unit 44 acquires the handle open / close signal output from the handle position detection unit 42 (step S13).

[0040] As described above, the handle open / close signal is a signal that indicates whether the handle 23 of the circuit breaker 2 is in an open state or a closed state. The handle position detection unit 42 detects the mechanical position of the handle holding unit 31 when outputting the handle open signal in the handle open / close signal. The handle holding unit 31 is set to a state in which it holds the handle 23, and changes its position in accordance with the opening and closing operation of the handle 23. Therefore, as shown in (c) of FIG. 6, the output timing of the handle open signal output from the handle position detection unit 42 is time t3, which is later than time t2 when the circuit breaker 2 trips and the current value i1 of the circuit breaker 2 becomes zero.

[0041] The determination unit 44 determines whether or not the cause of the trip of the circuit breaker 2 is an overcurrent, based on the current detection signal from the current detection unit 41 and the handle open / close signal from the handle position detection unit 42 (step S14). If the current detection signal from the current detection unit 41 is an ON output and the handle open / close signal from the handle position detection unit 42 is a handle open signal, the determination unit 44 determines that the cause of the trip of the circuit breaker 2 is an overcurrent.

[0042] In step S14, if it is determined that the cause of the trip of the circuit breaker 2 is not due to an overcurrent (NO in step S14), the determination unit 44 returns to step S13 and repeats each process. 6, for example, during the period from time t1 to time t2 when the current value i1 of the circuit breaker 2 exceeds the predetermined threshold, the current detection signal is an ON output, but the handle open / close signal is a handle closed signal. Therefore, the determination in step S14 in FIG. 3 is NO, and the process returns to step S13.

[0043] On the other hand, if it is determined in step S14 that the cause of the tripping of the circuit breaker 2 is an overcurrent, that is, if it is determined that the current detection signal is an ON output and the handle opening / closing signal is a handle open signal (YES in step S14), the judgment unit 44 determines that the circuit breaker 2 is in an abnormal trip state and stops the re-closing function of the circuit breaker 2 (step S15). 6, for example, at time t3 when a handle open signal is output from the handle position detection unit 42, it is determined that the current detection signal is an ON output and the handle open / close signal is a handle open signal. Therefore, as shown in (e), at time t4, a determination signal indicating that the circuit breaker 2 is in an abnormal trip state is output from the determination unit 44.

[0044] In step S14, if it is determined that the cause of the trip of the circuit breaker 2 is not due to an overcurrent within the predetermined time (NO in step S14), the process returns to step S10 and each process is repeated.

[0045] Next, the flowchart shown in FIG. 3 will be described with reference to a second determination example when the value of the current flowing through the circuit breaker 2 exceeds the predetermined threshold value. 7 is a time chart for explaining the second determination example, in which (a) to (e) of FIG. 7 show signals similar to (a) to (e) of FIG.

[0046] As described above, if it is detected in step S11 that the current value flowing through the circuit breaker 2 exceeds the predetermined threshold (YES in step S11), the current detection unit 41 outputs a current detection signal indicating that the current value has exceeded the predetermined threshold to the judgment unit 44 for a predetermined period of time (step S12). As shown in (a) and (b) of FIG. 7, at time t5 when the current value i2 exceeds the predetermined threshold, the current detection signal is output from the current detection unit 41 continuously for a predetermined time.

[0047] Next, the determination unit 44 acquires the handle open / close signal output from the handle position detection unit 42 (step S13). The handle open / close signal is a signal that changes depending on the open / close state of the handle 23, but in the second judgment example shown in Figure 7, the circuit breaker 2 does not trip due to the flow of current value i2, so the handle close signal remains as shown in (c).

[0048] Therefore, in step S14, although the current detection signal is an ON output, the handle open / close signal is a handle closed signal, so the determination unit 44 continues to determine NO. Therefore, the trip determination signal remains a non-abnormal trip determination signal, as shown in (e) of Figure 7. An example of such a current value i2 is an instantaneous current such as a noise current.

[0049] In this way, if a current detection signal is output continuously for a predetermined period of time based on a momentary overcurrent such as a noise current, a handle open signal is not output, and therefore no determination is made that an abnormal trip has occurred.

[0050] Next, the flowchart shown in FIG. 3 will be described with reference to an example of determination when the value of the current flowing through the circuit breaker 2 does not exceed the predetermined threshold value. Fig. 8 is a time chart showing an example of determination when the value of the current flowing through the circuit breaker 2 does not exceed a predetermined threshold value. Note that (a) to (e) in Fig. 8 show signals similar to (a) to (e) in Fig. 6.

[0051] As shown in FIG. 8(a), even if the value of the current i3 flowing through the circuit breaker 2 does not exceed the predetermined threshold, a trip of unknown cause may occur, for example, at time t6.

[0052] In this case, when the circuit breaker 2 trips, the state of the handle 23 of the circuit breaker 2 changes from a closed state to an open state, and as shown in (c) of Figure 8, a handle open signal is output at time t7, a short time after time t6 when the current value i3 becomes zero.

[0053] As described above, if it is detected in step S11 that the value of the current flowing through the circuit breaker 2 does not exceed the predetermined threshold value (NO in step S11), the current detection unit 41 returns to step S10 and repeats each process. Therefore, the process does not proceed to step S12.

[0054] Since the current value i3 does not exceed the predetermined threshold, the current detection signal indicating that the predetermined threshold has been exceeded remains in the OFF state, as shown in FIG. 8(b).

[0055] In this way, if an unknown trip occurs when the current does not exceed the predetermined threshold, the current detection signal is not output as an ON signal, and therefore, even if a handle open signal is output, a determination signal indicating an abnormal trip is not output, as shown in FIG. 8(e). Therefore, the determination unit 44 causes the drive unit 51 to drive the handle holding unit 31 via the handle control unit 32, thereby re-closing the circuit breaker 2. As a result, current begins to flow through the circuit breaker 2 at time t8, as shown in FIG. 8(a). Furthermore, at time t9, a handle closed signal is output from the handle position detection unit 42, as shown in FIG. 8(c).

[0056] (Variation 1) Next, a case will be described in which the determining device 4 determines whether or not the cause of the breaker 2 entering a tripped state is an overcurrent, based on the current detection signal and the voltage non-detection signal. FIG. 4 is a flowchart for determining whether or not the cause of the breaker 2 entering a tripped state is an overcurrent based on the current detection signal and the voltage undetection signal. First, the flowchart shown in FIG. 4 will be described with reference to FIG. 6, which shows a first determination example when the value of the current flowing through the circuit breaker 2 exceeds a predetermined threshold value.

[0057] The processing contents of steps S20 to S22 in FIG. 4 are the same as the processing contents of steps S10 to S12 in FIG.

[0058] Following step S22, the determination unit 44 acquires the detection signal output from the voltage detection unit 43, that is, the detection signal indicating whether or not a voltage is being output to the secondary side of the circuit breaker 2 (step S23). As shown in (d) of Figure 6, a voltage undetected signal indicating that no voltage is detected on the secondary side of circuit breaker 2 is output at time t10 so as to synchronize with time t2 when circuit breaker 2 trips and the current value i1 of circuit breaker 2 becomes zero.

[0059] The determination unit 44 determines whether or not the cause of the trip of the circuit breaker 2 is an overcurrent, based on the current detection signal from the current detection unit 41 and the detection signal (voltage undetected signal) from the voltage detection unit 43 (step S24). When the current detection signal from the current detection unit 41 is an ON output and the voltage detection unit 43 is outputting a voltage undetected signal, the determination unit 44 determines that the cause of the trip of the circuit breaker 2 is an overcurrent.

[0060] In step S24, if it is determined that the cause of the trip of the circuit breaker 2 is not due to an overcurrent (NO in step S24), the determination unit 44 returns to step S23 and repeats each process. 6, for example, during the period from time t1 when the current value i1 of the circuit breaker 2 exceeds the predetermined threshold to time t2 when the circuit breaker 2 trips and the current value i1 becomes zero, the current detection signal is in the ON state but the voltage non-detection signal is not output. Therefore, the determination in step S14 in FIG. 4 is NO, and the process returns to step S23.

[0061] On the other hand, if it is determined in step S24 that the cause of the tripping of the circuit breaker 2 is an overcurrent, i.e., if it is determined that the current detection signal is an on output and a voltage non-detection signal is being output from the voltage detection unit 43 (YES in step S24), the judgment unit 44 determines that the circuit breaker 2 is in an abnormal trip state and stops the re-closing function of the circuit breaker 2 (step S25). 6, for example, at time t10 when the voltage non-detection signal is output from the voltage detection unit 43, it is determined that the current detection signal is an ON output and that the voltage non-detection signal is being output from the voltage detection unit 43. Therefore, as shown in (e), at time t11, the determination unit 44 outputs a determination signal indicating that the circuit breaker 2 is in an abnormal trip state.

[0062] In addition, in step S24, if a predetermined time has elapsed during which the current detection signal has been output as ON, and it is determined that the cause of the tripping of the circuit breaker 2 is not due to an overcurrent (NO in step S24), the process returns to step S20 and each process is repeated.

[0063] (Variation 2) Figure 5 is a flowchart in which the determination device 4 determines whether the cause of the circuit breaker 2 entering a tripped state is an overcurrent, based on the current detection signal output from the current detection unit 41, the handle opening / closing signal output from the handle position detection unit 42, and the voltage undetection signal output from the voltage detection unit 43.

[0064] In step S35, for example, when the current detection signal from the current detection unit 41 is an on output, the handle opening / closing signal from the handle position detection unit 42 is a handle open signal, and a voltage undetected signal is output from the voltage detection unit 43, the judgment unit 44 judges that the cause of the tripping of the circuit breaker 2 is an overcurrent. The processing content of each step in FIG. 5 is the same as the processing content of the flowcharts shown in FIGS.

[0065] (Action and effect) In the conventional device, as shown in Fig. 9, the current value i4 flowing through the circuit breaker 2 exceeds a predetermined threshold value at time t14, for example, and continues to flow for a predetermined time, causing the circuit breaker 2 to trip and become zero at time t15, for example. When the current value i4 flowing through the circuit breaker 2 exceeds the predetermined threshold value at time t14, a current detection signal indicating that the predetermined threshold value has been exceeded is output from the current detection unit 41, as shown in Fig. 9(b). Then, when the circuit breaker 2 trips and the current value i4 becomes zero and is equal to or less than the predetermined threshold value, the current detection signal becomes an off output at time t15.

[0066] Furthermore, when the circuit breaker 2 trips, the state of the handle 23 of the circuit breaker 2 changes from the closed state to the open state. However, as described above, the handle position detection unit 42 detects the mechanical position of the handle holding unit 31 when detecting the position of the handle 23, and therefore there is a delay in the detection timing. For this reason, as shown in FIG. 9(c), the rising timing t16 of the handle open / close signal output from the handle position detection unit 42 is delayed relative to the time t15 at which the current value i4 becomes zero. In this way, since the handle open / close signal is output with a delay after the current detection signal is turned off, there are cases in which the determination unit 44 cannot accurately determine the occurrence of an abnormal trip caused by an overcurrent using the handle open / close signal output from the handle position detection unit 42.

[0067] Furthermore, when the circuit breaker 2 trips, the contacts within the circuit breaker 2 become non-conductive, and the voltage on the secondary side becomes zero. When the voltage on the secondary side of the circuit breaker 2 becomes zero, as shown in FIG. 9(d), a voltage undetected signal indicating that there is no voltage on the secondary side of the circuit breaker 2 is output from the voltage detection unit 43. However, due to a timing error, the output timing of the voltage undetected signal may occur after the current detection signal is turned off. Therefore, if the output timing of the voltage undetected signal occurs after the current detection signal is turned off, it may not be possible to accurately determine the occurrence of an abnormal trip caused by an overcurrent using the voltage undetected signal output from the voltage detection unit 43.

[0068] In this way, in conventional devices, even if the circuit breaker trips due to an overcurrent, if the current value flowing through the circuit breaker has already fallen below a predetermined threshold value at the time the circuit breaker handle is lowered or the voltage non-detection signal is output from the voltage detection unit 43, it may not be possible to determine that the cause of the tripping state is an overcurrent.

[0069] In contrast, according to the configuration of the determination device 4 of this embodiment, the current detection unit 41 is configured to hold a current detection signal indicating that the current value has exceeded the predetermined threshold for a predetermined time after the current value has exceeded the predetermined threshold. Therefore, even if the current value flowing through the circuit breaker 2 has already fallen below the predetermined threshold when the handle 23 is lowered, if a handle open signal is detected during the predetermined time period during which the current detection signal is held, it is possible to determine that the cause of the circuit breaker 2 entering a tripped state is an overcurrent based on the current detection signal and the handle open / close signal. In this way, the configuration of the determination device 4 can improve the accuracy of determining whether the cause of the circuit breaker 2 entering a tripped state is an overcurrent.

[0070] Furthermore, the determination device 4 may determine whether or not the cause of the circuit breaker 2 entering the tripped state is an overcurrent, based on the current detection signal and a voltage undetected signal indicating that no voltage is being detected on the secondary side of the circuit breaker 2. According to this configuration, even if the value of the current flowing through the circuit breaker 2 has already fallen below the predetermined threshold value at the time the handle 23 is lowered, if a voltage undetected signal indicating that no voltage is being detected on the secondary side of the circuit breaker 2 is detected while the current detection signal is held for the predetermined time, it can be determined that the cause of the circuit breaker 2 entering the tripped state is an overcurrent, based on the current detection signal and the voltage undetected signal. Furthermore, since the voltage detection unit 43 has a higher response rate than, for example, the handle position detection unit 42, the determination time of the determination unit 44 can be shortened.

[0071] Furthermore, according to the determination device 4, the voltage detection unit 43 is connected to the contact for the secondary voltage of the circuit breaker 2, which further improves the responsiveness of the voltage detection unit 43. Note that the voltage detection unit 43 may be configured not to be directly connected to the contact for the secondary voltage of the circuit breaker 2, but to be connected to a portion electrically connected to the contact.

[0072] Furthermore, the determining unit 44 of the determining device 4 may determine whether or not the cause of the circuit breaker 2 entering the tripped state is an overcurrent based on the current detection signal and at least one of a handle open / close signal indicating that the handle 23 of the circuit breaker 2 has been detected to be in the open state and a voltage non-detection signal indicating that no voltage has been detected on the secondary side of the circuit breaker 2. This configuration further improves the accuracy of determining whether or not the cause of the circuit breaker 2 entering the tripped state is an overcurrent.

[0073] The automatic reclosing device 3 also includes a determination device 4, a handle holding unit 31 attached to the handle 23 of the circuit breaker 2, and a handle control unit 32 that controls the operation of the handle holding unit 31 based on the determination result of the determination device 4. According to this configuration, by attaching the handle holding unit 31 that matches the shape of the handle 23 to the handle 23, the handle control unit 32 can quickly transition the handle 23 of the circuit breaker 2 from the open state to the closed state via the handle holding unit 31 and its drive mechanism.

[0074] Furthermore, when the current detection signal and the voltage non-detection signal are used for the determination, the handle holding portion 31 that matches the shape of the handle 23 of each type of circuit breaker 2 is not required, and the cost of parts can be reduced.

[0075] Furthermore, by combining the detection signals of both the handle position detection unit 42 and the voltage detection unit 43 in the judgment process, the automatic re-closing device 3 can distinguish whether the handle holding unit 31 has been moved to an avoidance position for maintenance, or whether the circuit breaker 2 has tripped due to an overcurrent and the position of the handle holding unit 31 has moved.

[0076] The present invention is not limited to the above-described embodiments, and can be freely modified, improved, etc. The material, shape, dimensions, numerical values, form, number, location, etc. of each component in the above-described embodiments are arbitrary and not limited as long as the present invention can be achieved.

[0077] For example, in the above embodiment, the case where the power distribution system is a single-phase three-wire system has been described, but the power distribution system is not limited to this system. For example, the power distribution system may be a single-phase two-wire system or a three-phase three-wire system.

[0078] In the above embodiment, the current sensors 24a and 24b are connected to the voltage lines L1 and L2 connected to the load terminals 22a and 22c, but this is not limiting. The current sensors may be connected to, for example, the voltage line L1 and the neutral line N, or the voltage line L2 and the neutral line N, or to any one of the voltage lines L1, L2, and the neutral line N, or to all of the voltage lines L1, L2, and the neutral line N. [Explanation of symbols]

[0079] 1: circuit breaker with automatic restart function, 2: circuit breaker, 3: automatic restart device, 4: determination device, 21: power supply side (primary side) terminal block, 21a to 21c: power supply side terminals, 22: load side (secondary side) terminal block, 22a to 22c: load side terminals, 23: handle, 24a, 24b: current sensors, 31: handle holding unit, 32: handle control unit, 33: display unit, 34: notification unit, 35: memory unit, 36: power supply unit, 41: current detection unit, 42: handle position detection unit (an example of a handle detection unit), 43: voltage detection unit, 44: determination unit, 51: drive unit, 121a to 121c: power supply side contacts, 122a to 122c: load side contacts, L1, L2: voltage lines, N: neutral line

Claims

1. a current detection unit that detects whether or not a value of a current flowing through the circuit breaker exceeds a predetermined threshold; a handle detection unit that detects whether a handle of the circuit breaker is in an open state; a determination unit that determines whether the cause of the circuit breaker being in a tripped state is an overcurrent; Equipped with the current detection unit is configured to hold a first detection signal indicating that the current value has exceeded the predetermined threshold for a predetermined time after the current value has exceeded the predetermined threshold, the determination unit determines whether or not the cause of the circuit breaker reaching the trip state is an overcurrent, based on the first detection signal and a second detection signal indicating that the handle of the circuit breaker has been detected to be in the open state. Judgment device.

2. a current detection unit that detects whether or not a value of a current flowing through the circuit breaker exceeds a predetermined threshold; a voltage detection unit that detects the presence or absence of a voltage on the secondary side of the circuit breaker; a determination unit that determines whether the cause of the circuit breaker being in a tripped state is an overcurrent; Equipped with the current detection unit is configured to hold a first detection signal indicating that the current value has exceeded the predetermined threshold for a predetermined time after the current value has exceeded the predetermined threshold, the determination unit determines whether or not the cause of the circuit breaker reaching a trip state is an overcurrent, based on the first detection signal and a third detection signal indicating that a voltage on the secondary side of the circuit breaker is not detected. Judgment device.

3. a current detection unit that detects whether or not a value of a current flowing through the circuit breaker exceeds a predetermined threshold; a handle detection unit that detects whether a handle of the circuit breaker is in an open state; a voltage detection unit that detects the presence or absence of a voltage on the secondary side of the circuit breaker; a determination unit that determines whether the cause of the circuit breaker being in a tripped state is an overcurrent; Equipped with the current detection unit is configured to hold a first detection signal indicating that the current value has exceeded the predetermined threshold for a predetermined time after the current value has exceeded the predetermined threshold, the determination unit determines whether or not the cause of the circuit breaker reaching the trip state is an overcurrent, based on the first detection signal and at least one of a second detection signal indicating that the handle of the circuit breaker has been detected to be in the open state and a third detection signal indicating that no voltage on the secondary side of the circuit breaker has been detected. Judgment device.

4. The voltage detection unit is connected to a voltage contact on the secondary side of the circuit breaker or to a portion electrically connected to the contact. The determination device according to claim 2 or 3.

5. A determination device described in any one of claims 1 to 4, wherein the specified time is 1 second or more.

6. The determination device according to any one of claims 1 to 5; a handle holding portion attached to a handle of the circuit breaker; a control unit that controls the operation of the handle holding unit based on the determination result of the determination device; An automatic re-insertion device.

7. A circuit breaker with an automatic reclosing function, comprising: the automatic reclosing device according to claim 6; and the circuit breaker.

8. A program that causes a determination device including a current detection unit, a handle detection unit, and a determination unit to execute the following process: causing the current detection unit to detect whether a value of a current flowing through the circuit breaker exceeds a predetermined threshold, and to hold a first detection signal indicating that the current value has exceeded the predetermined threshold for a predetermined time after the current value has exceeded the predetermined threshold; causing the handle detection unit to detect whether the handle of the circuit breaker is in an open state; a step of causing the determination unit to determine whether or not the cause of the circuit breaker reaching a trip state is an overcurrent, based on the first detection signal and a second detection signal indicating that the handle of the circuit breaker has been detected to be in an open state; A program that executes processing including

9. A program for causing a determination device including a current detection unit, a voltage detection unit, and a determination unit to execute the following process: causing the current detection unit to detect whether a value of a current flowing through the circuit breaker exceeds a predetermined threshold, and to hold a first detection signal indicating that the current value has exceeded the predetermined threshold for a predetermined time after the current value has exceeded the predetermined threshold; causing the voltage detection unit to detect the presence or absence of voltage on the secondary side of the circuit breaker; a step of causing the determination unit to determine whether or not the cause of the circuit breaker reaching a trip state is an overcurrent, based on the first detection signal and a third detection signal indicating that a voltage on the secondary side of the circuit breaker is not detected; A program that executes processing including

10. A program that causes a determination device including a current detection unit, a handle detection unit, a voltage detection unit, and a determination unit to execute the following process: causing the current detection unit to detect whether a value of a current flowing through the circuit breaker exceeds a predetermined threshold, and to hold a first detection signal indicating that the current value has exceeded the predetermined threshold for a predetermined time after the current value has exceeded the predetermined threshold; causing the handle detection unit to detect whether the handle of the circuit breaker is in an open state; causing the voltage detection unit to detect the presence or absence of voltage on the secondary side of the circuit breaker; a step of causing the determination unit to determine whether or not the cause of the circuit breaker reaching a trip state is an overcurrent, based on the first detection signal and at least one of a second detection signal indicating that a handle of the circuit breaker has been detected to be in an open state and a third detection signal indicating that a voltage on the secondary side of the circuit breaker has not been detected; A program that executes processing including

11. A program described in any one of claims 8 to 10, wherein the specified time is 1 second or more.

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