JP7694357B2 - Circuit breaker status diagnosis device, circuit breaker status diagnosis method, and program - Google Patents

Description

The present invention relates to a circuit breaker status diagnosis device, a circuit breaker status diagnosis method, and a program.

2. Description of the Related Art A circuit breaker status diagnosis device has been developed as a device that automatically measures the switching state (switching speed) of a circuit breaker in a normal operating state and transmits the measurement data (see, for example, Patent Document 1).
In order to measure the opening and closing characteristics of a circuit breaker in an extra-high voltage circuit, this type of circuit breaker status diagnosis device applies a low voltage (e.g., 3 to 5 V) from a measuring device to a free contact (spare contact) of a control circuit (e.g., a DC 110 V circuit) in the circuit breaker control panel, and detects changes in that voltage to measure the operating characteristics of the circuit breaker.

JP 2020-123525 A

However, in conventional technology, the measuring device circuit wiring (voltage 3-5V) is adjacent to the control circuit wiring (voltage DC 110V), and so it can be subject to induced noise caused by voltage and current changes in the control circuit wiring due to opening and closing operations, as well as surges. In addition, conventional technology can also be subject to induced noise caused by the opening and closing of the main circuit, which is an extra-high voltage. This noise is removed, for example, by an analog filter in the measuring device, but because the noise level is higher than the measuring device circuit voltage, it may not be possible to completely remove it with an analog filter. Depending on the conditions, it is possible that the state of the auxiliary contacts monitored by the measuring device will be misjudged, causing the measured value to deviate from the true value.

The present invention has been made in consideration of the above problems, and aims to provide a circuit breaker status diagnosis device, a circuit breaker status diagnosis method, and a program that distinguish noise, prevent erroneous judgments, and improve the accuracy of measurement values.

A circuit breaker status diagnosis device according to one aspect of the present invention includes a contact status detection unit that detects when the state of the contacts of an auxiliary switch of a circuit breaker is reversed, and a processing unit that sets the detected time as a provisional measurement value, and if the state of the contacts has not reversed a predetermined time after the detected time, determines that the state is noise and resets the provisional measurement value, and if the state of the contacts has reversed a predetermined time after the detected time, determines that the provisional measurement value is the time when the contacts were reversed.

In addition, in a circuit breaker status diagnosis device according to one aspect of the present invention, the processing unit may start detecting the status of the contacts after an opening/closing command is issued to the auxiliary switch, and may set the time of the first reversal after starting to detect the status of the auxiliary switch contacts based on a threshold value as the provisional measurement value.

In addition, in the circuit breaker status diagnosis device according to one aspect of the present invention, the processing unit may start detecting the status of the contacts after an opening/closing command is issued to the auxiliary switch, and may set the provisional measurement value as the reversal time at which reversals are detected consecutively within a predetermined time from the time of the first reversal after starting to detect the status of the auxiliary switch contacts based on a threshold value and no reversals are detected within a predetermined time after the detection.

In addition, in the circuit breaker status diagnosis device according to one aspect of the present invention, the processing unit may start detecting the status of the contacts, and after starting detection of the status of the auxiliary switch contacts based on a threshold, set the time of the first reversal as the first provisional measurement value, set the reversal time at which reversals are detected consecutively within a predetermined time from the time of the first reversal and no reversal is detected within a predetermined time after the detection as the second provisional measurement value, and determine that the determination is incorrect if the time difference between the first provisional measurement value and the second provisional measurement value is shorter than a judgment time, and determine that the determination is correct if the time difference is longer than the judgment time.

In addition, in a circuit breaker status diagnosis device according to one aspect of the present invention, the judgment time may be less than the operation time of the circuit breaker status diagnosis device, and the expected noise may be greater than the continuous noise time.

In one aspect of the present invention, a circuit breaker status diagnosis method includes a contact status detection unit that detects that the status of the contacts of an auxiliary switch of a circuit breaker has been reversed, and a processing unit that sets the detected time as a provisional measurement value, and if the status of the contacts has not been reversed a predetermined time after the detected time, determines that there is noise and resets the provisional measurement value, and if the status of the contacts has been reversed a predetermined time after the detected time, determines that the provisional measurement value is the time when the contacts were reversed.

A program according to one aspect of the present invention causes a computer to detect when the state of the contacts of an auxiliary switch of a circuit breaker is reversed, sets the detected time as a provisional measurement value, and if the state of the contacts has not reversed a predetermined time after the detected time, determines that this is noise and resets the provisional measurement value, and if the state of the contacts has reversed a predetermined time after the detected time, determines that the provisional measurement value is the time when the contacts were reversed.

According to an embodiment of the present invention, it is possible to distinguish noise, prevent erroneous judgments, and improve the accuracy of measurement values.

1 is a diagram illustrating a configuration example in which a circuit breaker state diagnosis device according to an embodiment is installed in a circuit breaker. 1 is a diagram illustrating an example of the configuration of a circuit breaker state diagnosis device according to an embodiment. FIG. 13 is a diagram for explaining noise caused by a control circuit. FIG. 13 is a diagram for explaining main circuit-induced noise. FIG. 11 is a diagram for explaining chattering processing. FIG. 13 is a diagram for explaining the principle of superposition of noise caused by a DC 110V control circuit and erroneous measurement in the case of an example of chattering t1 processing. FIG. 13 is a diagram for explaining the principle of superposition of noise caused by a DC 110V control circuit and erroneous measurement in the case of an example of chattering t2 processing. This is an example of actual measurement in which a large noise was superimposed on the detection circuit voltage of the auxiliary contact 4a of the circuit breaker at a timing before the reversal of the auxiliary contact 4a of the circuit breaker, resulting in an erroneous measurement of the contact determination time. An example of chattering t2 processing and superimposition of noise and erroneous measurement caused by the main circuit will be described. 11 is a flowchart of a determination procedure for removing the influence of noise, performed by a processing unit according to the embodiment. 11 is a flowchart of a determination procedure for removing the influence of noise, performed by a processing unit according to the embodiment. 13 is a timing chart showing a chattering t1 process in which noise is caused by DC 110V. This is a timing chart showing the process of chattering t2 when noise is caused by DC 110V. 4 is a timing chart of a process in which noise originates in a main circuit.

The following describes an embodiment of the present invention with reference to the drawings. Note that in the drawings used in the following description, the scale of each component has been appropriately altered so that each component is of a recognizable size.

[Outline of operation of circuit breaker status diagnosis device]
The circuit breaker status diagnosis device of the embodiment is permanently installed, for example, in a control panel included in a circuit breaker. In the circuit breaker, the measurement device circuit wiring (voltage 3 to 5 V) is adjacent to the control circuit wiring (voltage DC 110 V), and therefore may be subjected to induced noise due to voltage/current changes in the control circuit wiring accompanying opening and closing operations, surges, etc. In addition, the circuit breaker may be subjected to induced noise due to opening and closing of the main circuit, which is an extra-high voltage. For this reason, the circuit breaker status diagnosis device of the embodiment determines whether or not this noise is the cause based on the state change of the auxiliary contacts, thereby reducing erroneous determinations.

[Circuit breaker status diagnostic system]
1 is a diagram showing an example of a configuration in which a circuit breaker state diagnosis device according to the present embodiment is installed in a circuit breaker 10. The circuit breaker 10 is installed in an electric power station such as a power plant, a substation, or a switchyard.

First, the configuration and operation of the circuit breaker 10 will be briefly described.
The circuit breaker 10 includes a bushing 1-1, a bushing 1-2, a main circuit conductor 2-1, a main circuit conductor 2-2, a main contact 3, a circuit breaker auxiliary contact 4a, a circuit breaker auxiliary contact 4b, a current sensor 5, an opening coil 6, a closing coil 7, a circuit breaker device 9, and a circuit breaker status diagnosis device 100. The circuit breaker 10 is connected to an external operation unit 20, and the external operation unit 20 is connected to a control power source (DC) 8.

The interrupter 9 includes a main contact 3. Bushings 1-1 and 1-2 are provided on the top of the interrupter 9. Main circuit conductors 2-1 and 2-2 are arranged inside bushings 1-1 and 1-2, respectively. Main circuit conductors 2-1 and 2-2 are connected to the power transmission line, etc., via metal terminals, respectively.

The main contact 3 includes two electrodes, and during normal operation, the two electrodes are connected (hereinafter referred to as the "closed state"). The main contact 3 can instantly cut off electricity by separating the two electrodes. In other words, by isolating the two electrodes, the two electrodes are in an open state (hereinafter referred to as the "open state"). The main contact 3 has transitioned to the open state, but when returning from the open state to the closed state, it can be returned to the closed state by performing a closing operation.

When the main contact 3 is in the closed state, the breaker 10 transitions to an open state when the opening coil 6 is operated by operating the external operation unit 20 connected to the control power source 8. In other words, the main contact 3 of the breaker 9 is cut off. Specifically, the opening coil 6 is operated by turning on the switch s1 connected to the opening coil 6 of the external operation unit 20.

When the circuit breaker 10 is in the open state, the closing coil 7 is operated by operating the external operation unit 20 connected to the control power source 8, and the circuit breaker 10 transitions to the closed state. In other words, the main contact 3 of the circuit breaker 9 is connected. Specifically, the closing coil 7 is operated by turning on the switch s2 connected to the closing coil 7 of the external operation unit 20.

When the open coil 6 operates and the circuit breaker 10 enters an open state, the current flowing through the open coil 6 is detected by the current sensor 5. The current detected by the current sensor 5 is output to the circuit breaker status diagnosis device 100. Specifically, the wire connecting the switch s1 of the external operation unit 20 and the open coil 6 is clamped by the clamp-type current sensor 5, and the current sensor 5 detects the current flowing through the open coil 6 when the switch s1 is turned on.

When the closing coil 7 operates to place the circuit breaker 10 in a closed state, the current flowing through the closing coil 7 is detected by the current sensor 5. The current detected by the current sensor 5 is output to the circuit breaker status diagnosis device 100. Specifically, the wire connecting the switch s2 of the external operation unit 20 and the open coil 6 is clamped by the clamp-type current sensor 5, and the current sensor 5 detects the current flowing through the closing coil 7 when the switch s2 is turned on.

The circuit breaker auxiliary contact 4a is included in an auxiliary switch that is mechanically linked to the drive shaft of the main contact 3, and is open when the main contact 3 is in the open state, and is closed when the main contact 3 is in the closed state. In other words, when the main contact 3 changes from the open state to the closed state, the circuit breaker auxiliary contact 4a changes from open to closed in conjunction with the operation of the main contact 3. When the main contact 3 changes from the closed state to the open state, the circuit breaker auxiliary contact 4a changes from closed to open in conjunction with the operation of the main contact 3. The circuit breaker auxiliary contact 4a is also connected to the circuit breaker status diagnosis device 100.

The circuit breaker auxiliary contact 4b is included in an auxiliary switch that is mechanically linked to the drive shaft of the main contact 3, and is closed when the main contact 3 is in the open state, and is open when the main contact 3 is in the closed state. In other words, when the main contact 3 changes from the open state to the closed state, the circuit breaker auxiliary contact 4b changes from closed to open in conjunction with the operation of the main contact 3. When the main contact 3 changes from the closed state to the open state, the circuit breaker auxiliary contact 4b changes from open to closed in conjunction with the operation of the main contact 3. The circuit breaker auxiliary contact 4b is also connected to the circuit breaker status diagnosis device 100.

Next, a configuration example and an operation example of the circuit breaker state diagnosis device 100 will be described with reference to FIG. 1 and FIG.
2 is a diagram showing an example of the configuration of the circuit breaker status diagnosis device according to the present embodiment. As shown in Fig. 2, the circuit breaker status diagnosis device 100 includes a resistor R1, a resistor R2, a waveform shaping circuit 101, a processing unit 102, a display unit 103, an operation unit 104, a timer unit 105, a storage unit 106, an output unit 107, and a command acquisition unit 108.

When detecting whether the auxiliary contacts 4a, 4b of the circuit breaker are in the on or off state when the circuit breaker 10 operates, there have been cases where the contacts are erroneously determined to be in the on state when they are actually in the off state due to the effects of noise. For this reason, the circuit breaker state diagnosis device 100 checks the state of the contacts for a specified period of time, removes the effects of noise, and then determines the state of the contacts.

One end of the circuit breaker auxiliary contact 4a is pulled up by a resistor R1 connected to a positive power supply (+V) and is connected to the processing unit 102, and the other end is grounded.
The auxiliary circuit breaker contact 4b has one end pulled up by a resistor R2 connected to a positive power supply (+V) and connected to the processing unit 102, and the other end grounded.

The waveform shaping circuit 101 performs waveform shaping on the current detected by the current sensor 5 and outputs the waveform shaped signal to the processing unit 102.

The processing unit 102 measures the opening and closing operation time of the circuit breaker 10 and diagnoses the condition based on the signal of the circuit breaker auxiliary contact 4a, the signal of the circuit breaker auxiliary contact 4b, and the signal waveform-shaped by the waveform shaping circuit 101. The processing unit 102 displays the diagnosis result on the display unit 103. Alternatively, the processing unit 102 outputs the diagnosis result to an external device (not shown). The processing performed by the processing unit 102 will be described later.
The processing unit 102 also includes, for example, a contact state detection unit 1021 that acquires a signal from the circuit breaker auxiliary contact and converts it into a digital signal, a current information acquisition unit 1022 that acquires waveform-shaped current information and converts it into a digital signal, and a noise determination unit 1023 that determines whether the information detected as the contact signal is noise or not.

The display unit 103 is, for example, a liquid crystal display device, an organic EL (Electro Luminescence), a lamp, etc. The display unit 103 displays, for example, the diagnosis results of the circuit breaker 10, the current time, etc.

The operation unit 104 is, for example, a mechanical switch. The operation unit 104 is operated by a user when switching the circuit breaker status diagnosis device 100 between the on and off states, switching the display, switching settings, etc.

The timekeeping unit 105 measures time when determining the state of the contacts, which will be described later. The timekeeping unit 105 may measure the current time, for example.

The memory unit 106 stores measurement results such as thresholds, programs, clocked times, waveform levels, etc. required for processing by the circuit breaker status diagnosis device 100.

The output unit 107 outputs the result determined by the processing unit 102 to an external device. The output unit 107 includes a wired or wireless communication unit or interface. The external device may be, for example, a personal computer, a tablet terminal, a smartphone, a dedicated terminal, etc.

The command acquisition unit 108 acquires commands from a control device or a control unit that controls the circuit breaker 10, and outputs the acquired commands to the processing unit 102. Note that the command acquisition unit 108 may be provided in the processing unit 102.

Note that the configuration shown in FIG. 2 is an example and is not limited to this. The circuit breaker status diagnosis device 100 may include other components.

[Principle of noise generation]
Next, the principle of noise generation will be described.
Fig. 3 is a diagram for explaining noise caused by a control circuit. As shown in Fig. 3, in addition to the contact circuit (applied voltage is the internal control circuit voltage of the circuit breaker status diagnosis device 100, e.g. DC 3 to 5 V) connected to the control panel, a large number of DC 110 V control wirings are housed (g11). These wirings are often bundled together and are electrically coupled to each other (capacitance, mutual inductance).

This type of control DC 110V is two orders of magnitude higher than the internal control circuit voltage DC 3 to 5V of the circuit breaker status diagnosis device 100, so it is prone to appear as induction (electrostatic induction, electromagnetic induction) noise (g12) in the contact circuit for the circuit breaker status diagnosis device 100, especially when voltage and current changes occur, and there have been cases where this could not be completely removed by the analog filter, resulting in erroneous measurements.

Figure 4 is a diagram for explaining main circuit-induced noise. As shown in Figure 4, the breaker main contacts and the extra-high voltage main circuit are installed close to the control panel. The control panel is electrostatically shielded by a metal case and is grounded, so the extra-high voltage main circuit voltage does not appear in the breaker status diagnosis device 100 due to electrostatic induction coupling. However, a surge voltage generated by the opening and closing of a nearby switch may propagate through the control circuit cable, or an induced voltage may occur due to electromagnetic induction from the main circuit, which may easily appear as induced noise in the contact circuit for the breaker status diagnosis device 100 and the current sensor 5 (g21). In either case, the noise level is high compared to the internal control circuit voltage DC 3 to 5 V of the breaker status diagnosis device 100 and the threshold value of the current sensor 5 (for example, about 1 V), and there are cases where it cannot be removed by an analog filter and results in erroneous measurement.

[Effects of noise]
Next, an example of the influence when the above-mentioned noise occurs will be described.
First, chattering processing for chattering, which is one type of noise, will be described. Fig. 5 is a diagram for explaining chattering processing. In Fig. 5, the horizontal axis is time, and the vertical axis is signal level. A waveform g101 represents the state of the auxiliary contact of the circuit breaker, and a waveform g102 is a signal waveform after the result detected by the current sensor 5 is waveform-shaped. In the waveform g101, a high level represents the OFF state of the auxiliary contact of the circuit breaker, and a low level represents the ON state of the auxiliary contact of the circuit breaker. In the following description, the state of the auxiliary contact of the circuit breaker will be described using negative logic (ON=low level, OFF=high level), but it may also be positive logic (ON=high level, OFF=low level).

Information on the auxiliary contacts of the circuit breaker (4a, 4b) may contain chattering (fluttering of the contacts from on to off or off to on) as shown in Figure 5. In Figure 5, the chattering process determines whether the timing at which the auxiliary contacts of the circuit breaker change state is time t1 (the timing at which they first turn on or off) or time t2 (the timing at which they become completely on or off). The contact reversal time is t1-t0 or t2-t0, respectively, and is used depending on the purpose of the contact information. Time t0 is the timing at which an opening/closing command is issued, and is the starting time for measuring the opening and closing time. In the following explanation, the process of taking the timing at which the auxiliary contacts of the circuit breaker change state as time t1 is referred to as "chattering t1 process", and the process of taking the timing at which the auxiliary contacts of the circuit breaker change state as time t2 is referred to as "chattering t2 process".

An example of chattering t1 processing will be described with reference to FIG.
Fig. 6 is a diagram for explaining the principle of superposition of noise caused by a DC 110V control circuit and erroneous measurement in the case of an example of chattering t1 processing. In Fig. 6, the horizontal axis is time and the vertical axis is signal level. A waveform g111 represents the state of the auxiliary contact of the breaker, and a waveform g112 is a signal waveform after the result detected by the current sensor 5 is shaped.
If chattering processing is performed at time t1, the time when the contact first reverses state (the time when the auxiliary contact of the circuit breaker turns on), if noise occurs at time t3 and the threshold for determining the on state of the auxiliary contact of the circuit breaker falls below the threshold, the contact reversal time will be erroneously measured as t3 - t0 instead of the actual time t1 - t0.

An example of chattering t2 processing will be described with reference to FIG.
7 is a diagram for explaining the principle of superposition of noise caused by a DC 110V control circuit and erroneous measurement in the case of an example of chattering t2 processing. In FIG. 7, the horizontal axis is time and the vertical axis is signal level. A waveform g121 represents the state of the auxiliary contact of the breaker, and a waveform g122 is a signal waveform after the result detected by the current sensor 5 is shaped.
If chattering processing is performed at time t2 (the timing when the circuit breaker was last turned off), noise such as that shown in Figure 7 will enter at time t3, and if the noise falls below the threshold for determining the off state of the auxiliary contacts of the circuit breaker, the contact reversal time will be erroneously measured as t3 - t0 instead of the actual time t1 - t0.

Next, an example in which noise and chattering are superimposed will be described.
Fig. 8 shows an example of an actual measurement in which a large noise was superimposed on the detection circuit voltage of the circuit breaker auxiliary contact 4a at a timing before the circuit breaker auxiliary contact 4a reversed, resulting in an erroneous measurement of the contact determination time. In Fig. 8, the horizontal axis represents time and the vertical axis represents signal level. Waveform g151 is the waveform of the current flowing through the closing coil 7, waveform g152 is the output waveform of the current sensor 5, waveform g153 is the voltage waveform across the circuit breaker auxiliary contact 4a, and waveform g154 is the voltage waveform across the circuit breaker auxiliary contact 4b.

As shown in Figure 8, noise is more likely to be superimposed at a higher level when the auxiliary contacts of the circuit breaker are in the OFF state (high impedance in the open circuit state) than when they are in the ON state (low impedance in the open circuit state). In the measurement example of Figure 8, the high-level portion of the voltage waveform between the auxiliary contacts of the circuit breaker 4a corresponds to when the auxiliary contacts of the circuit breaker are OFF (high impedance in the open circuit state).

Next, an example of chattering t2 processing and superimposition of noise and erroneous measurement caused by the main circuit will be described.
Fig. 9 illustrates an example of chattering t2 processing and superimposition of noise caused by the main circuit and erroneous measurement. In Fig. 9, the horizontal axis is time and the vertical axis is signal level. A waveform g201 represents the state of the auxiliary contact of the breaker, and a waveform g202 is a signal waveform after the result detected by the current sensor 5 is shaped.

Noise caused by the main circuit is characterized by the fact that it is superimposed on both the contact state detection circuit and the coil current sensor. The current sensor 5 detects the current in the closing coil 7 or the opening coil 6, and determines that the circuit breaker 10 is operating when the voltage output of the current sensor 5 exceeds the judgment threshold, setting this as the start point t0 of time measurement. At the same time as the start point t0, the state of the auxiliary contacts 4a and 4b of the circuit breaker are read to determine the current state of the circuit breaker 10 (on or off). This section explains the case where the current state of the circuit breaker 10 (on or off) is determined.

In the example of Figure 9, when reading the state of the circuit breaker auxiliary contacts at the timing when noise of a level equivalent to the operation of the circuit breaker 10 is applied to the current sensor 5 (time t0), the circuit breaker auxiliary contacts should be read as off. However, if noise happens to be superimposed on the contact state detection circuit at that timing and the reading is below the threshold for determining the on state of the circuit breaker auxiliary contacts, the circuit breaker auxiliary contacts may be erroneously determined to be in the on state.
In Fig. 9, when the auxiliary contact of the circuit breaker is in the OFF state, noise due to the operation of other switches enters both the contact detection circuit and the coil current detection circuit, and the circuit breaker 10 is determined to be operating even though it is not operating. In this way, when the chattering process is set to (the timing when it first turned on), the operating time is erroneously determined to be t2-t0, and when the chattering process is set to (the timing when it last turned off), the operating time is erroneously measured to be t3-t0.

[Noise Judgment Method]
Next, a procedure for determining whether the processing unit 102 of this embodiment eliminates the influence of noise will be described.
10 and 11 are flowcharts of a determination procedure for removing the influence of noise performed by the processing unit according to this embodiment. As described above, Fig. 10 and Fig. 11 are examples of processing using negative logic. In the case of positive logic, H (high level) and L (low level) of each processing are reversed.

(Step S1) The processing unit 102 determines whether or not there is an opening/closing command to the circuit breaker 10, i.e., an output from the current sensor 5. If the processing unit 102 determines that there is an opening/closing command (Step S1; YES), it proceeds to the processing of Step S2. If the processing unit 102 determines that there is no opening/closing command (Step S1; NO), it repeats Step S1 again and waits for an opening/closing command.

(Step S2) The processing unit 102 causes the timing unit 105 to start timing the opening and closing times.

(Step S3) The processing unit 102 determines whether or not the contact signal from the circuit breaker auxiliary contact is H (high level). If the contact signal is H (Step S3; YES), the processing unit 102 proceeds to processing of Step S4. If the contact signal is not H (Step S3; NO), the processing unit 102 proceeds to processing of Step S11 (FIG. 11).

(Step S4) The processing unit 102 temporarily stores the time when the contact signal first detects L (low level) in the memory unit 106 as a provisional measurement value.

(Step S5) The processing unit 102 causes the timing unit 105 to start the timer operation.

(Step S6) The processing unit 102 determines whether the timer has elapsed a first predetermined time (e.g., Δt4 in FIG. 12). If the timer has elapsed the first predetermined time (Step S6; YES), the processing unit 102 proceeds to the process of Step S7. If the timer has not elapsed the first predetermined time (Step S6; NO), the processing unit 102 repeats the process of Step S6.

(Step S7) The processing unit 102 determines whether the contact signal from the auxiliary contact of the circuit breaker is L or not. If the contact signal from the auxiliary contact of the circuit breaker is L (Step S7; YES), the processing unit 102 proceeds to processing of step S9. If the contact signal from the auxiliary contact of the circuit breaker is not L (Step S7; NO), the processing unit 102 proceeds to processing of step S8.

(Step S8) The processing unit 102 determines that the detected signal inversion is noise. The processing unit 102 resets the time of the provisional measurement value provisionally stored in the memory unit 106, resets the timer, and returns the process to step S4.

(Step S9) The processing unit 102 calculates the difference between the time-lapse start time in step S2 that was temporarily stored in the memory unit 106 and the time temporarily stored in step S4, obtains the opening/closing operation time, and proceeds to the processing of step S17.

(Step S11) The processing unit 102 temporarily stores in the memory unit 106 the time when H was last detected in the contact signal group.

(Step S12) The processing unit 102 causes the timing unit 105 to start the timer operation.

(Step S13) The processing unit 102 determines whether the contact signal is L or not. If the processing unit 102 determines that the contact signal is L (Step S13; YES), the processing unit 102 proceeds to processing of Step S14. If the processing unit 102 determines that the contact signal is not L (Step S13; NO), the processing unit 102 proceeds to processing of Step S15.

(Step S14) Because the contact signal has been inverted during the first predetermined time, the processing unit 102 resets the temporarily stored time, resets the timer, and returns the process to step 11.

(Step S15) The processing unit 102 determines whether or not a second predetermined time (e.g., Δt5 in FIG. 13) has elapsed. If the second predetermined time has elapsed (Step S15; YES), the processing unit 102 proceeds to the process of Step S16. If the second predetermined time has not elapsed (Step S15; NO), the processing unit 102 returns to the process of Step S13.

(Step S16) The processing unit 102 calculates the difference between the time-lapse start time in step S2 that was temporarily stored in the memory unit 106 and the time temporarily stored in step S11, obtains the opening/closing operation time, and proceeds to the processing of step S17.

(Step S17) The processing unit 102 determines whether the opening/closing operation time calculated in step S9 or step 16 is less than a third predetermined time (e.g., t5 in FIG. 14). If the calculated opening/closing operation time is equal to or greater than the third predetermined time (step 17: NO), the processing unit 102 determines that the calculated opening/closing operation time is normal and proceeds to the processing of step S18. If the calculated opening/closing operation time is less than the third predetermined time (step 17: YES), the processing unit 102 determines that the calculated opening/closing operation time is abnormal, discards the measured data, and ends the processing.

(Step S18) The processing unit 102 stores the measured data, such as the measurement time and the switch operation state determined from the state of the auxiliary contacts, in the memory unit 106 and ends the process.

The processing procedures shown in Figs. 10 and 11 are merely examples, and are not limiting. In addition, the detection of the first H or L and the detection of the last H or L in Figs. 10 and 11 will be explained using the following specific examples.

(Specific example of chattering t1 processing caused by DC 110V)
Next, a specific example of chattering t1 processing when noise is caused by DC 110V will be described with reference to FIG. 10 and FIG. 12.
12 is a timing chart of chattering t1 processing when noise is caused by DC 110V. In FIG. 12, the vertical axis is time and the horizontal axis is signal level. A waveform g301 represents the state of the auxiliary contact of the breaker, and a waveform g302 is a signal waveform detected by the current sensor 5.

When the noise is caused by DC 110V and chattering t1 processing is being performed, the processing unit 102 performs processing by focusing on the fact that the noise generated by induction is caused by the opening and closing of voltage and current due to contact operation, so the time width is relatively narrow, and the group position is shifted from the operation timing of the target contact.

The time t3 of the "first change timing" is set as a provisional measurement value (step S4), and after the first predetermined time Δt4 has elapsed (steps S5, S6), the state of the contact is checked again (step S7), and if the contact has not reversed (is not in the ON state), time t3 is reset (step S8), and t1 is measured again by measuring the "first change timing" (step S4). The contact state is checked again Δt4 after time t1, and since the contact has reversed (is ON), it is determined to be time t1 (step S9).

The detection of the "first change timing" is the time when the signal level becomes equal to or lower than the L threshold for the first time after detection starts, as shown in waveform g301. Therefore, after the first predetermined time Δt4 has elapsed, the processing unit 102 checks the state of the contacts and confirms or resets the provisional measurement value to resume detection.

In this way, when the noise is caused by DC 110V and chattering t1 processing is performed, the processing unit 102 detects that the state of the contacts of the auxiliary switch of the circuit breaker has been reversed, sets the detected time as the provisional measurement value, resets the provisional measurement value if the contact state has not been reversed a predetermined time after the detection time, and determines the provisional measurement value as the time when the contacts were reversed if the contact state was reversed a predetermined time after the detection time. In addition, the processing unit 102 starts contact state detection after an opening/closing command to the switch, i.e., after the current sensor 5 detects a current, and sets the time when the contacts were first reversed after starting to detect the state of the auxiliary switch contacts based on the threshold value as the provisional measurement value.

(Specific example of chattering t2 processing caused by DC 110V)
Next, a specific example of chattering t2 processing when noise is caused by DC 110V will be described using FIG. 13 with reference to FIG. 10 and FIG. 11.
13 is a timing chart of chattering t2 processing when noise is caused by DC 110V. In FIG. 13, the vertical axis is time and the horizontal axis is signal level. A waveform g351 represents the state of the auxiliary contact of the breaker, and a waveform g352 is a signal waveform detected by the current sensor 5.

When the noise is caused by DC 110V and chattering t2 processing is used, note that the noise generated by induction is caused by the opening and closing of voltage and current due to contact operation, so the time width is relatively narrow, and the group position is shifted from the operation timing of the target contact.

Time t2, the "timing of the last change," is taken as a provisional measurement value (step S11), and if there is no change in the contacts until the second predetermined time Δt5 has elapsed (steps S12, S13), time t2 is determined as the measurement value, and if there is a change in the contacts, time t2, the provisional measurement value "timing of the last change," is remeasured and updated. As a result, no change in time t3 is measured.

The processing unit 102 determines the time t2' when the signal level first becomes equal to or above the H threshold after detection starts, as shown in waveform g351, as the "timing of the first change". The processing unit 102 then considers the signals detected within a predetermined time from this time as a continuous signal. The processing unit 102 then detects the time t2, which is the last time that signals are detected continuously from time t2' and then detected within the predetermined time, as the "timing of the last change". The processing unit 102 also checks the state of the contacts for a second predetermined time Δt5, and confirms or resets the provisional measurement value to resume detection.

In this way, when the noise is caused by DC 110V and chattering t2 processing is performed, the processing unit 102 detects that the state of the contacts of the auxiliary switch of the circuit breaker has been reversed, sets the detected time as a provisional measurement value, resets the provisional measurement value if the contact state has not been reversed within a predetermined time from the detection time, and determines the provisional measurement value as the time when the contacts were reversed if the contact state was reversed after the predetermined time from the detection time. In addition, the processing unit 102 starts contact state detection after an opening/closing command to the switch, i.e., after the current sensor 5 detects a current, and sets the reversal time at which reversals are detected continuously within a predetermined time from the time of the first reversal and no reversals are detected within a predetermined time after detection based on the threshold value as the provisional measurement value.

(Main circuit cause)
Next, a specific example of noise originating from the main circuit will be described with reference to FIG. 14 while also referring to FIG. 10 and FIG.
14 is a timing chart of the process of noise caused by the main circuit. In FIG. 14, the vertical axis is time and the horizontal axis is signal level. A waveform g401 represents the state of the auxiliary contact of the breaker, and a waveform g402 is a signal waveform after the result detected by the current sensor 5 is shaped.

In addition, because noise caused by the main circuit occurs at the moment the current in the main circuit is interrupted, the time width (corresponding to t3-t0) is short, typically on the order of a few ms, which is sufficiently shorter than the operating time of the original circuit breaker 10 (on the order of tens to hundreds of ms).

With this in mind, if the calculated opening and closing operation time (steps S9, S16) is less than the judgment time t5 (third predetermined time) (step S17), the processing unit 102 determines that the measurement is incorrect and does not perform any further data processing (storage of measured values, transmission, etc.). Note that if the measurement time t3-t0 is greater than the judgment time t5, the processing unit 102 treats it as a normal measurement.

The processing unit 102 sets the third predetermined time t5 to, for example, the expected operating time of the circuit breaker status diagnosis device 100 > t5.

In this way, when the noise is caused by the main circuit, the processing unit 102 determines that the judgment is incorrect if the measured opening and closing operation time of the auxiliary switch of the circuit breaker is shorter than the judgment time set based on the expected circuit breaker operation time, and determines that the judgment is correct if the measured opening and closing operation time of the auxiliary switch of the circuit breaker is longer than the judgment time set based on the expected circuit breaker operation time.

As described above, in this embodiment, a reversal of the contact state of the auxiliary switch of the circuit breaker is detected, and the detected time is set as a provisional measurement value. If the contact state has not reversed a predetermined time after the detected time, the provisional measurement value is reset, and if the contact state has reversed a predetermined time after the detected time, the provisional measurement value is determined as the time when the contact was reversed.

As a result, according to this embodiment, by using an algorithm that identifies and eliminates this noise, it is possible to prevent erroneous judgments and improve the accuracy of measurement values.

In addition, a program for realizing all or part of the functions of the circuit breaker status diagnosis device 100 in the present invention may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed to perform all or part of the processing performed by the circuit breaker status diagnosis device 100. Note that the term "computer system" here includes hardware such as an OS and peripheral devices. The term "computer system" also includes a WWW system equipped with a homepage providing environment (or display environment). The term "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into computer systems. The term "computer-readable recording medium" also includes those that hold a program for a certain period of time, such as volatile memory (RAM) inside a computer system that becomes a server or client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line.

The above program may also be transmitted from a computer system in which the program is stored in a storage device or the like to another computer system via a transmission medium, or by transmission waves in the transmission medium. Here, the "transmission medium" that transmits the program refers to a medium that has the function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The above program may also be one that realizes part of the above-mentioned functions. Furthermore, it may be a so-called difference file (difference program) that can realize the above-mentioned functions in combination with a program already recorded in the computer system.

The above describes the form for carrying out the present invention using an embodiment, but the present invention is not limited to such an embodiment, and various modifications and substitutions can be made without departing from the spirit of the present invention.

10...circuit breaker, 1-1, 1-2...bushing, 2-1, 2-2...main circuit conductor, 3...main contact, 4a...circuit breaker auxiliary contact, 4b...circuit breaker auxiliary contact, 5...current sensor, 6...open coil, 7...closing coil, 9...breaker, 100...circuit breaker status diagnostic device, 20...external operation unit, R1, R2...resistor, 101...wave shaping circuit, 102...processing unit, 103...display unit, 104...operation unit, 105...timer unit, 106...storage unit, 107...output unit, 108...command acquisition unit, 1021...contact status detection unit, 1022...current information acquisition unit, 1023...noise determination unit

Claims (7)

a contact state detection unit that detects a reversal of a contact state of an auxiliary switch of the circuit breaker;
a processing unit which sets the detected time as a provisional measurement value, determines that the state of the contact has not been inverted a predetermined time after the detected time and resets the provisional measurement value, and determines that the state of the contact has been inverted a predetermined time after the detected time as the provisional measurement value as the time when the contact was inverted;
A circuit breaker status diagnosis device comprising: The processing unit starts detecting the state of the contacts after an opening/closing command is issued to the auxiliary switch, and sets the time of the first reversal after starting detection of the state of the contacts of the auxiliary switch based on a threshold value as the provisional measurement value.
The circuit breaker condition diagnosis device according to claim 1 . the processing unit starts detecting the state of the contacts after an opening/closing command is issued to the auxiliary switch, and determines, as the provisional measurement value, a reversal time at which reversals are detected consecutively within a predetermined time from the time of the first reversal after the start of detection of the state of the contacts of the auxiliary switch based on a threshold value and no reversal is detected within a predetermined time after the detection.
The circuit breaker condition diagnosis device according to claim 1 . the processing unit starts detecting the state of the contacts, and determines the time of the first reversal after starting detection of the state of the contacts of the auxiliary switch based on a threshold value as the first provisional measurement value, and determines the reversal time at which reversals are detected consecutively within a predetermined time from the time of the first reversal and no reversal is detected within a predetermined time after the detection as the second provisional measurement value, and determines that the determination is incorrect when the time difference between the first provisional measurement value and the second provisional measurement value is shorter than a judgment time, and determines that the determination is correct when the time difference is longer than the judgment time.
The circuit breaker condition diagnosis device according to claim 1 . The judgment time is less than the operation time of the circuit breaker status diagnosis device, and is greater than the noise time during which the expected noise is continuous.
The circuit breaker condition diagnosis device according to claim 4. The contact state detection unit detects that the state of the contact of the auxiliary switch of the circuit breaker is reversed,
a processing unit sets the detected time as a provisional measurement value, and if the state of the contact has not been inverted after a predetermined time from the detected time, determines that the state is noise and resets the provisional measurement value, and if the state of the contact has been inverted after the predetermined time from the detected time, establishes the provisional measurement value as the time when the contact was inverted.
Circuit breaker condition diagnostic method. On the computer,
Detects when the contact state of the auxiliary switch of the circuit breaker is reversed,
The detected time is taken as a provisional measurement value,
If the state of the contacts is not inverted after a predetermined time from the time of detection, it is determined that the contacts are noise, and the provisional measurement value is reset.
if the state of the contact is reversed after the predetermined time from the detected time, the provisional measurement value is determined as the time when the contact was reversed.
program.

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