Circuit Breaker State Diagnosis Device, Circuit Breaker State Diagnosis Method, and Program

Abstract

To provide a circuit breaker status diagnostic device, a circuit breaker status diagnostic method, and a program that discriminates noise, prevents erroneous determination, and improves the accuracy of measurement values.SOLUTION: A circuit breaker status diagnosis device includes a contact state detection unit that detects that the state of the contact of an auxiliary switch of a circuit breaker is reversed, and a processing unit that uses a detected time as a provisional measurement value, determines noise when the state of the contact is not reversed after a predetermined time from the detection time, resets the provisional measurement value, and determines the temporary measurement value as the time when the state of the contact is reversed when the state of the contact is reversed after a predetermined time from the detected time.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a circuit breaker state diagnosis device, a circuit breaker state diagnosis method, and a program.

Background Art

[0002] A circuit breaker state diagnosis device has been developed as a device that automatically measures the opening / closing state (opening / closing speed) of a circuit breaker in a normal operation state and transmits measurement data (see, for example, Patent Document 1). Such a circuit breaker state diagnosis device measures the operating characteristics of a circuit breaker by applying a low voltage (for example, 3 to 5 V) from a measuring device to an empty contact (spare contact) of a control circuit (for example, a DC 110 V circuit) in a circuit breaker control panel in order to measure the opening / closing characteristics of the circuit breaker in a special high-voltage circuit, and detecting the change in the voltage.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the prior art, since the measuring device circuit wiring (voltage 3 to 5 V) is adjacent to the control circuit wiring (voltage DC 110 V), it may receive induced noise caused by voltage and current changes and surges in the control circuit wiring associated with the opening / closing operation, or induced noise caused by the opening / closing of the main circuit, which is a special high voltage. These noises are removed by, for example, an analog filter of the measuring device, but there are cases where they cannot be completely eliminated by the analog filter because the noise level is higher than the measuring device circuit voltage. Depending on the conditions, it is also conceivable that the state of the auxiliary contact monitored by the measuring device is misjudged and the measured value deviates from the true value.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a circuit breaker state diagnosis device, a circuit breaker state diagnosis method, and a program that discriminate noise, prevent misjudgment, and improve the accuracy of measured values.

Means for Solving the Problems

[0006] A circuit breaker state diagnosis device according to an aspect of the present invention includes a contact state detection unit that detects that the state of the contact of the auxiliary switch of the circuit breaker has reversed, uses the detected time as a provisional measurement value, and determines that it is noise if the state of the contact has not reversed after a predetermined time from the detected time, and resets the provisional measurement value, and a processing unit that determines the provisional measurement value as the time when the contact has reversed if the state of the contact has reversed after the predetermined time from the detected time.

[0007] Further, in the circuit breaker state diagnosis device according to an aspect of the present invention, the processing unit may start detecting the state of the contact after an opening / closing command is issued to the auxiliary switch, and use the time when the contact first reverses after the start of detecting the state of the contact of the auxiliary switch based on a threshold value as the provisional measurement value.

[0008] Further, in the circuit breaker state diagnosis device according to an aspect of the present invention, the processing unit may start detecting the state of the contact after an opening / closing command is issued to the auxiliary switch, and use, as the provisional measurement value, the reversal time at which reversals are continuously detected every predetermined time within a predetermined time from the time when the contact first reverses after the start of detecting the state of the contact of the auxiliary switch based on a threshold value and no reversal is detected within a predetermined time after the detection.

[0009] Also, in the circuit breaker state diagnosis device according to one aspect of the present invention, the processing unit starts detecting the state of the contact, and after starting to detect the state of the contact of the auxiliary switch based on a threshold value, the time when it first reverses is set as the first provisional measurement value, and the reversal times that are continuously detected every predetermined time within a predetermined time from the time when it first reverses and for which no reversal is detected within a predetermined time after the detection are set as the second provisional measurement values. When the time difference between the first provisional measurement value and the second provisional measurement value is shorter than the determination time, it may be determined that it is a false determination, and when the time difference is longer than the determination time, it may be determined that it is a correct determination.

[0010] Also, in the circuit breaker state diagnosis device according to one aspect of the present invention, the determination time may be less than the operating time of the circuit breaker state diagnosis device and greater than the noise time during which assumed noise continues.

[0011] In the circuit breaker state diagnosis method according to one aspect of the present invention, a contact state detection unit detects that the state of the contact of the auxiliary switch of the circuit breaker has reversed, and a processing unit sets the detected time as a provisional measurement value. If the state of the contact has not reversed after a predetermined time from the detected time, it is determined that it is noise and the provisional measurement value is reset. If the state of the contact has reversed after the predetermined time from the detected time, the provisional measurement value is determined as the time when the contact reversed.

[0012] The program according to one aspect of the present invention causes a computer to detect that the state of the contact of the auxiliary switch of the circuit breaker has reversed, sets the detected time as a provisional measurement value, determines that it is noise and resets the provisional measurement value if the state of the contact has not reversed after a predetermined time from the detected time, and determines the provisional measurement value as the time when the contact reversed if the state of the contact has reversed after the predetermined time from the detected time.

Advantages of the Invention

[0013] According to the embodiment of the present invention, noise can be discriminated, false determination can be prevented, and the accuracy of the measurement value can be improved.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

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Figure 8

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Figure 10

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Figure 12

Figure 13

Figure 14

Mode for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings used in the following description, the scales of the respective members are appropriately changed in order to make the respective members recognizable sizes.

[0016] [Outline of the operation of the circuit breaker state diagnosis device] The circuit breaker state diagnosis device of the embodiment is permanently installed, for example, in a control panel included in the circuit breaker. Inside the circuit breaker, since the measurement device circuit wiring (voltage 3 to 5V) is adjacent to the control circuit wiring (voltage DC110V), it may receive induced noise caused by voltage and current changes and surges in the control circuit wiring associated with the opening and closing operations. Also, inside the circuit breaker, it may receive induced noise due to the opening and closing of the main circuit, which is extra-high voltage. Therefore, the circuit breaker state diagnosis device of this embodiment discriminates whether it is this noise or not from the state change of the auxiliary contact, and reduces misjudgment.

[0017] [Circuit breaker state diagnosis system] FIG. 1 is a diagram showing a configuration example in which the circuit breaker state diagnosis device of this embodiment is installed in a circuit breaker. The circuit breaker 10 is installed in an electrical station such as a power plant, a substation, or a switchyard.

[0018] First, the configuration of the circuit breaker 10 and the outline of the operation will be 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, a release coil 6, an input coil 7, a circuit breaker device 9, and a circuit breaker state diagnosis device 100. Also, the circuit breaker 10 is connected to an external operation unit 20, and the external operation unit 20 is connected to a control power supply (DC) 8.

[0019] The circuit breaker device 9 includes the main contact 3. The bushing 1-1 and the bushing 1-2 are provided above the circuit breaker device 9. Inside the bushing 1-1 and the bushing 1-2, the main circuit conductor 2-1 and the main circuit conductor 2-2 are respectively arranged. The main circuit conductor 2-1 and the main circuit conductor 2-2 are connected to a transmission line or the like via metal terminals, respectively.

[0020] The main contact 3 includes two electrodes. During normal operation, the two electrodes are connected (hereinafter referred to as the "closed state"). The main contact 3 can instantaneously cut off electricity when the two electrodes are separated. That is, when the two electrodes are isolated, the two electrodes enter the open state (hereinafter referred to as the "open state"). When the main contact 3 has shifted to the open state and needs to return from the open state to the closed state, an closing operation is performed to enable the closed state.

[0021] When the main contact 3 is in the closed state and the release coil 6 operates by operating the external operation unit 20 connected to the control power supply 8, the circuit breaker 10 shifts to the open state. That is, the main contact 3 of the interrupting device 9 is interrupted. Specifically, when the switch s1 connected to the release coil 6 of the external operation unit 20 is turned on, the release coil 6 operates.

[0022] When the circuit breaker 10 is in the open state and the closing coil 7 operates by operating the external operation unit 20 connected to the control power supply 8, the circuit breaker 10 shifts to the closed state. That is, the main contact 3 of the interrupting device 9 is connected. Specifically, when the switch s2 connected to the closing coil 7 of the external operation unit 20 is turned on, the closing coil 7 operates.

[0023] When the release coil 6 operates and the circuit breaker 10 enters the open state, the current flowing through the release coil 6 is detected by the current sensor 5. The current detected by the current sensor 5 is output to the circuit breaker state diagnostic device 100. Specifically, the electric wire connecting the switch s1 of the external operation unit 20 and the release coil 6 is clamped by the clamp-type current sensor 5, and the current sensor 5 detects the current flowing through the release coil 6 when the switch s1 is turned on.

[0024] When the input coil 7 operates and the circuit breaker 10 is in the on state, the current flowing through the input coil 7 is detected by the current sensor 5. The current detected by the current sensor 5 is output to the circuit breaker state diagnosis device 100. Specifically, the electric wire connecting the switch s2 of the external operation unit 20 and the release coil 6 is sandwiched by the clamp-type current sensor 5, and the current sensor 5 detects the current flowing through the input coil 7 when the switch s2 is turned on.

[0025] The circuit breaker auxiliary contact 4a is included in the auxiliary switch that is mechanically linked to the drive shaft of the main contact 3. When the main contact 3 is in the open state, it is open, and when the main contact 3 is in the on state, it is closed. That is, when the main contact 3 changes from the open state to the on 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 on 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. Also, the circuit breaker auxiliary contact 4a is connected to the circuit breaker state diagnosis device 100.

[0026] The circuit breaker auxiliary contact 4b is included in the auxiliary switch that is mechanically linked to the drive shaft of the main contact 3. When the main contact 3 is in the open state, it is closed, and when the main contact 3 is in the on state, it is open. That is, when the main contact 3 changes from the open state to the on 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 on 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. Also, the circuit breaker auxiliary contact 4b is connected to the circuit breaker state diagnosis device 100.

[0027] Next, a configuration example and an operation example of the circuit breaker state diagnosis device 100 will be described with reference to FIGS. 1 and 2. FIG. 2 is a diagram showing a configuration example of the circuit breaker state diagnosis device according to the present embodiment. As shown in FIG. 2, the circuit breaker state 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 timing unit 105, a storage unit 106, an output unit 107, and a command acquisition unit 108.

[0028] When detecting whether the states of the breaker auxiliary contacts 4a and 4b are on or off when the breaker 10 operates, there may be a misjudgment that the contacts are in the on state although they are in the off state due to the influence of noise. Therefore, the breaker state diagnosis device 100 checks the state of the contacts for a predetermined time to remove the influence of noise and determines the state of the contacts.

[0029] One end of the breaker auxiliary contact 4a is pulled up by a resistor R1 connected to the positive power supply (+V) and is connected to the processing unit 102, and the other end is grounded. One end of the breaker auxiliary contact 4b is pulled up by a resistor R2 connected to the positive power supply (+V) and is connected to the processing unit 102, and the other end is grounded.

[0030] 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.

[0031] Based on the signal of the breaker auxiliary contact 4a, the signal of the breaker auxiliary contact 4b, and the signal waveform-shaped by the waveform shaping circuit 101, the processing unit 102 measures the opening and closing operation time of the breaker 10 and diagnoses the state. The processing unit 102 causes the display unit 103 to display the diagnosis result. Or, the processing unit 102 outputs the diagnosis result to an external device (not shown). Note that the processing performed by the processing unit 102 will be described later. Also, the processing unit 102 includes, for example, a contact state detection unit 1021 that acquires the signal of the breaker auxiliary contact and converts it into a digital signal, a current information acquisition unit 1022 that acquires the 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.

[0032] The display unit 103 is, for example, a liquid crystal display device, an organic EL (Electro Luminescence), a lamp, or the like. The display unit 103 displays, for example, the diagnosis result of the breaker 10, the current time, and the like.

[0033] The operation unit 104 is, for example, a mechanical switch. The operation unit 104 is operated by a user when switching between the on state and the off state of the circuit breaker state diagnosis device 100, switching the display, switching the settings, and the like.

[0034] The timing unit 105 performs timing when determining the state of the contact described later. The timing unit 105 may, for example, be timing the current time.

[0035] The storage unit 106 stores measurement results such as thresholds, programs, timed times, waveform levels, etc. necessary for the processing of the circuit breaker state diagnosis device 100.

[0036] 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 is, for example, a personal computer, a tablet terminal, a smartphone, a dedicated terminal, or the like.

[0037] The command acquisition unit 108 acquires a command from a control device or control unit that controls the circuit breaker 10, and outputs the acquired command to the processing unit 102. Note that the command acquisition unit 108 may be provided in the processing unit 102.

[0038] Note that the configuration shown in FIG. 2 is an example and is not limited thereto. The circuit breaker state diagnosis device 100 may include other components.

[0039] [Principle of noise generation] Next, the principle of noise generation will be described. FIG. 3 is a diagram for explaining noise caused by the control circuit. As shown in FIG. 3, inside the control panel, in addition to the contact circuit connected to the circuit breaker state diagnosis device 100 (the applied voltage is the internal control circuit voltage of the circuit breaker state diagnosis device 100, for example, DC3 to 5V), a large number of control DC110V wirings are accommodated (g11). These wirings are often bundled and are electrically coupled to each other (capacitance, mutual inductance).

[0040] Such a DC 110V for control has a voltage two digits higher than the internal control circuit voltage DC 3 - 5V of the circuit breaker state diagnostic device 100. Therefore, especially at the timing when voltage and current changes occur, it is likely to appear as induced (electrostatic induction, electromagnetic induction) noise (g12) in the contact circuit for the circuit breaker state diagnostic device 100. There was a case where it could not be completely removed by the analog filter and resulted in mismeasurement.

[0041] Figure 4 is a diagram for explaining the noise caused by the main circuit. As shown in Figure 4, close to the control panel, the main contacts of the circuit breaker and the extra-high voltage main circuit are installed. The control panel is a metal enclosure that is electrostatically shielded and grounded, and the extra-high voltage main circuit voltage does not appear in the circuit breaker state diagnostic device 100 due to electrostatic induction coupling. However, the surge voltage generated by the opening and closing of the adjacent switch is propagated through the control circuit cable, or an induced voltage due to electromagnetic induction from the main circuit is generated, and it is likely to appear as induced noise (g21) in the contact circuit for the circuit breaker state diagnostic device 100 or the current sensor 5. In either case, compared with the internal control circuit voltage DC 3 - 5V of the circuit breaker state diagnostic device 100 or the threshold value of the current sensor 5 (for example, about 1V), the level is large as noise, and there was a case where it could not be removed by the analog filter and mismeasurement occurred.

[0042] [Influence of Noise] Next, an example of the influence when the above-mentioned noise occurs will be explained. First, the chattering process for chattering, which is one of the noises, will be explained. Figure 5 is a diagram for explaining the chattering process. In Figure 5, the horizontal axis is time and the vertical axis is the signal level. The waveform g101 represents the state of the auxiliary contacts of the circuit breaker, and the waveform g102 is the signal waveform after shaping the result detected by the current sensor 5. In the waveform g101, the high level represents the off state of the auxiliary contacts of the circuit breaker, and the low level represents the on state of the auxiliary contacts of the circuit breaker. In the following explanation, the state of the auxiliary contacts of the circuit breaker is explained in negative logic (on = low level, off = high level), but positive logic (on = high level, off = low level) may also be used.

[0043] The information of the breaker auxiliary contacts (4a, 4b) may include chattering (the variation in the timing when the contacts turn on from off or off from on) as shown in Fig. 5. In Fig. 5, the chattering process is to determine whether the timing when the breaker auxiliary contacts change state is set as time t1 (the timing when it first turns on or off) or time t2 (the timing when it is completely on or off). The contact reversal time is either t1 - t0 or t2 - t0, and it is used appropriately according to the purpose of using the contact information. Note that time t0 is the timing when the opening / closing command is issued and is the starting time for measuring the opening / closing time. In the following description, the process of setting the timing when the breaker auxiliary contacts change state as time t1 is referred to as "chattering t1 process", and the process of setting the timing when the breaker auxiliary contacts change state as time t2 is referred to as "chattering t2 process".

[0044] An example of the chattering t1 process will be described with reference to Fig. 6. Fig. 6 is a diagram for explaining the principle of the superposition of noise caused by the DC110V control circuit and the mismeasurement in the case of the chattering t1 process example. In Fig. 6, the horizontal axis represents time, and the vertical axis represents the signal level. The waveform g111 represents the state of the breaker auxiliary contacts, and the waveform g112 is the signal waveform after wave-forming the result detected by the current sensor 5. When the chattering process is set as time t1 (the timing when the contacts first reverse state, i.e., the timing when the breaker auxiliary contacts turn on), if noise enters at time t3 and the threshold for determining the on state of the breaker auxiliary contacts is exceeded, the contact reversal time, which should originally be t1 - t0, will be mismeasured as t3 - t0.

[0045] An example of the chattering t2 process will be described with reference to Fig. 7. Fig. 7 is a diagram for explaining the principle of the superposition of noise caused by the DC110V control circuit and the mismeasurement in the case of the chattering t2 process example. In Fig. 7, the horizontal axis represents time, and the vertical axis represents the signal level. The waveform g121 represents the state of the breaker auxiliary contacts, and the waveform g122 is the signal waveform after wave-forming the result detected by the current sensor 5. When the chattering process is set at time t2 (the timing when it last turned off), noise as shown in Fig. 7 enters at time t3. If the noise falls below the threshold for determining the off state of the breaker auxiliary contact, the contact reversal time will be mismeasured as t3 - t0 instead of the original t1 - t0.

[0046] Next, an example where noise and chattering are superimposed will be described. Fig. 8 is an actual measurement example where significant noise is superimposed on the detection circuit voltage of the breaker auxiliary contact 4a before the reversal of the breaker auxiliary contact 4a, resulting in mismeasurement of the contact determination time. In Fig. 8, the horizontal axis represents time and the vertical axis represents the signal level. Waveform g151 is the current waveform flowing through the energizing coil 7, waveform g152 is the output waveform of the current sensor 5, waveform g153 is the voltage waveform between the breaker auxiliary contacts 4a, and waveform g154 is the voltage waveform between the breaker auxiliary contacts 4b.

[0047] As shown in Fig. 8, noise superimposition is more likely to occur at a higher level when the breaker auxiliary contact is in the off state (high impedance in the circuit open state) than when it is in the on state (low impedance in the circuit short - circuit state). In the measurement example of Fig. 8, the high - level portion of the voltage waveform between the breaker auxiliary contacts 4a corresponds to the time when the breaker auxiliary contact is off (high impedance in the circuit open state).

[0048] Next, an example of superimposition and mismeasurement of noise caused by the main circuit in the case of chattering t2 processing will be described. Fig. 9 illustrates an example of superimposition and mismeasurement of noise caused by the main circuit in the case of chattering t2 processing. In Fig. 9, the horizontal axis represents time and the vertical axis represents the signal level. Waveform g201 represents the state of the breaker auxiliary contact, and waveform g202 is the signal waveform after shaping the result detected by the current sensor 5.

[0049] The noise caused by the main circuit is characterized in that noise is superimposed on both the contact state detection circuit and the coil current sensor. The current of the input coil 7 or the release coil 6 is detected by the current sensor 5, and when the voltage output of the current sensor 5 exceeds the determination threshold value, it is determined that the breaker 10 operates, and the starting point t0 of time measurement is set. The case where the states of the breaker auxiliary contacts 4a and 4b are read simultaneously with the starting point t0 to determine the current state (on state or off state) of the breaker 10 will be described.

[0050] In the example of FIG. 9, when reading the breaker auxiliary contact state at the timing (time t0) when noise of a level corresponding to the operation of the breaker 10 is added to the current sensor 5, if the breaker auxiliary contact should be read as off but, by chance, noise is superimposed on the contact state detection circuit at that timing and the threshold value for determining the on state of the breaker auxiliary contact is not reached, the breaker auxiliary contact may be erroneously determined to be in the on state. In FIG. 9, the breaker auxiliary contact is in the off state, noise caused by the operation of another switch is input to both the contact detection circuit and the coil current detection circuit, and it is determined that the breaker 10 is operating although the breaker 10 is not operating. When the chattering process is set as (the timing when it first turns on), the operation time is erroneously determined as t2 - t0, and when it is set as (the timing when it finally turns off), the operation time is erroneously measured as t3 - t0.

[0051] [Noise determination method] Next, the determination procedure for excluding the influence of noise performed by the processing unit 102 of the present embodiment will be described. FIGS. 10 and 11 are flowcharts of the determination procedure for excluding the influence of noise performed by the processing unit according to the present embodiment. Note that FIGS. 10 and 11 are examples of negative logic processing as described above. In the case of positive logic, the H (high level) and L (low level) of each process are reversed.

[0052] (Step S1) The processing unit 102 determines whether there is an opening / closing command for the circuit breaker 10, that is, whether there is an output from the current sensor 5. When the processing unit 102 determines that there is an opening / closing command (Step S1; YES), it proceeds to the processing of Step S2. When the processing unit 102 determines that there is no opening / closing command (Step S1; NO), it repeats Step S1 again and waits for the opening / closing command.

[0053] (Step S2) The processing unit 102 causes the timing unit 105 to start timing the opening / closing time.

[0054] (Step S3) The processing unit 102 determines whether the contact signal from the circuit breaker auxiliary contact is H (high level). When the processing unit 102 determines that the contact signal is H (Step S3; YES), it proceeds to the processing of Step S4. When the processing unit 102 determines that the contact signal is not H (Step S3; NO), it proceeds to the processing of Step S11 (Figure 11).

[0055] (Step S4) The processing unit 102 temporarily stores in the storage unit 106, as a temporary measurement value, the time when L (low level) is first detected in the contact signal.

[0056] (Step S5) The processing unit 102 causes the timing unit 105 to start the timer operation.

[0057] (Step S6) The processing unit 102 determines whether the timer has elapsed the first predetermined time (for example, Δt4 in Figure 12). When the processing unit 102 determines that the timer has elapsed the first predetermined time (Step S6; YES), it proceeds to the processing of Step S7. When the processing unit 102 determines that the first predetermined time has not elapsed (Step S6; NO), it repeats the processing of Step S6.

[0058] (Step S7) The processing unit 102 determines whether the contact signal from the circuit breaker auxiliary contact is L. When the processing unit 102 determines that the contact signal from the circuit breaker auxiliary contact is L (Step S7; YES), it proceeds to the processing of Step S9. When the processing unit 102 determines that the contact signal from the circuit breaker auxiliary contact is not L (Step S7; NO), it proceeds to the processing of Step S8.

[0059] (Step S8) The processing unit 102 determines that the inversion of the detected signal is noise. The processing unit 102 resets the time of the estimated value temporarily stored in the storage unit 106, resets the timer, and returns the process to step S4.

[0060] (Step S9) The processing unit 102 calculates the difference between the start time over time in step S2 temporarily stored in the storage unit 106 and the time temporarily stored in step S4, obtains the opening / closing operation time, and proceeds to the process of step S17.

[0061] (Step S11) The processing unit 102 temporarily stores in the storage unit 106 the time when H was last detected in the contact signal group.

[0062] (Step S12) The processing unit 102 starts the timer operation in the timing unit 105.

[0063] (Step S13) The processing unit 102 determines whether the contact signal is L. If the processing unit 102 determines that the contact signal is L (step S13; YES), it proceeds to the process of step S14. If the processing unit 102 determines that the contact signal is not L (step S13; NO), it proceeds to the process of step S15.

[0064] (Step S14) Since the contact signal has inverted within the first predetermined time, the processing unit 102 resets the temporarily stored time, resets the timer, and returns the process to step 11.

[0065] (Step S15) The processing unit 102 determines whether the second predetermined time (for example, Δt5 in FIG. 13) has elapsed. If the processing unit 102 determines that the second predetermined time has elapsed (step S15; YES), it proceeds to the process of step S16. If the processing unit 102 determines that the second predetermined time has not elapsed (step S15; NO), it returns to the process of step S13.

[0066] (Step S16) The processing unit 102 calculates the difference between the start time over time in Step S2 temporarily stored in the storage unit 106 and the time temporarily stored in Step S11, obtains the opening / closing operation time, and proceeds to the process of Step S17.

[0067] (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 (for example, t5 in FIG. 14). When 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 process of Step S18. When 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 process.

[0068] (Step S18) The processing unit 102 stores the measured data such as the measurement time and the opening / closing device operation state specified from the state of the auxiliary contact in the storage unit 106 and ends the process.

[0069] Note that the processing procedures shown in FIGS. 10 and 11 are merely examples and are not limited thereto. Also, in FIGS. 10 and 11, the detection of the first H or L and the detection of the last H or L will be described using the following specific examples.

[0070] (Specific Example of Chattering t1 Process Due to DC110V) Next, a specific example of the chattering t1 process caused by noise due to DC110V will be described with reference to FIG. 10 and using FIG. 12. FIG. 12 is a timing chart of the chattering t1 process caused by noise due to DC110V. In FIG. 12, the vertical axis represents time and the horizontal axis represents signal level. Waveform g301 represents the state of the breaker auxiliary contact, and waveform g302 is the signal waveform detected by the current sensor 5.

[0071] When the noise is caused by DC 110V and in the case of chattering t1 processing, the processing unit 102 pays attention to the fact that the noise generated by induction has a relatively narrow time width because it is caused by the voltage / current opening and closing due to the contact operation, and the group position is shifted from the operation timing of the target contact, and performs processing.

[0072] Hypothetically measure the time t3 of "the timing of the first change" as a measured value (step S4). After the elapse of Δt4 which is the first predetermined time (steps S5, S6), check the state of the contact again (step S7). If the contact has not reversed (if it is not in the on state), reset the time t3 (step S8), and measure t1 by measuring "the timing of the first change" again (step S4). Check the contact state again after Δt4 from the time t1 again. Since the contact has reversed (is in the ON state), determine it at the time t1 (step S9).

[0073] Note that the detection of "the timing of the first change" is, as in the waveform g301, the time when the signal level first becomes below the threshold value for L after starting the detection. Therefore, the processing unit 102 checks the state of the contact after the elapse of Δt4 which is the first predetermined time, determines or resets the hypothetical measured value, and resumes the detection.

[0074] In this way, when the noise is caused by DC 110V and in the case of chattering t1 processing, the processing unit 102 detects that the state of the contact of the auxiliary switch of the circuit breaker has reversed, uses the detected time as a hypothetical measured value, resets the hypothetical measured value if the state of the contact has not reversed after a predetermined time from the detected time, and determines the hypothetical measured value as the time when the contact has reversed if the state of the contact has reversed after a predetermined time from the detected time. Also, the processing unit 102 starts detecting the state of the contact after the opening / closing command for the switch, that is, after the current sensor 5 detects the current, and uses the time of the first reversal after the start of detecting the state of the contact of the auxiliary switch based on the threshold value as the hypothetical measured value.

[0075] (Specific example of chattering t2 processing caused by DC 110V) Next, with reference to FIGS. 10 and 11 and using FIG. 13, a specific example of the chattering t2 process caused by noise due to DC110V will be described. FIG. 13 is a timing chart of the chattering t2 process caused by noise due to DC110V. In FIG. 13, the vertical axis represents time and the horizontal axis represents signal level. Waveform g351 represents the state of the breaker auxiliary contact, and waveform g352 is the signal waveform detected by the current sensor 5.

[0076] In the case of the chattering t2 process caused by noise due to DC110V, note that the noise generated by induction has a relatively narrow time width because it is caused by the voltage and current opening and closing due to the contact operation, and the group position is shifted from the operation timing of the target contact.

[0077] Assume the time t2 of "the timing of the last change" as a provisional measurement value (step S11). If there is no change in the contact until the elapse of the second predetermined time Δt5 (steps S12, S13), the time t2 is determined as the measurement value and the time is fixed. If there is a change in the contact, the time t2 of the provisional measurement value "the timing of the last change" is re-measured and updated. As a result, the change in time t3 is not measured.

[0078] Note that the processing unit 102 sets the time t2' when the signal level first becomes equal to or higher than the threshold value for H as "the timing of the first change" as in waveform g351 after starting the detection. Then, the processing unit 102 regards the signals detected within a predetermined time from this time as continuous signals. Then, the processing unit 102 detects the time t2 that is continuously detected from the time t2' and is finally detected at the predetermined time as "the timing of the last change". Further, the processing unit 102 checks the state of the contact during the second predetermined time Δt5, determines or resets the provisional measurement value, and resumes the detection.

[0079] Thus, in the case of chattering t2 processing caused by noise due to DC 110V, the processing unit 102 detects that the state of the contact of the auxiliary switch of the circuit breaker has reversed, uses the detected time as a provisional measurement value, resets the provisional measurement value if the state of the contact has not reversed within a predetermined time from the detected time, and determines the provisional measurement value as the time when the contact has reversed if the state of the contact has reversed after the predetermined time from the detected time. Further, after the processing unit 102 issues an opening / closing command to the switch, that is, after the current sensor 5 detects the current, the processing unit 102 starts detecting the state of the contact, and uses, as the provisional measurement value, the time of the first reversal and each subsequent reversal detected continuously within a predetermined time from the time of the first reversal after the start of detecting the state of the contact of the auxiliary switch based on the threshold value, provided that no reversal is detected within a predetermined time after the detection.

[0080] (Caused by the main circuit) Next, a specific example of noise caused by the main circuit will be described with reference to FIGS. 10 and 11 and using FIG. 14. FIG. 14 is a timing chart of the process when the noise is caused by the main circuit. In FIG. 14, the vertical axis represents time and the horizontal axis represents the signal level. The waveform g401 represents the state of the auxiliary contact of the circuit breaker, and the waveform g402 is the signal waveform after the result detected by the current sensor 5 is shaped into a waveform.

[0081] Note that since the noise caused by the main circuit occurs at the moment of current interruption in the main circuit, the time width (corresponding to t3 - t0) is short, generally on the order of several ms, and is sufficiently shorter than the operating time of the original circuit breaker 10 (on the order of several tens of ms to several hundreds of ms).

[0082] Taking this into account, when the calculated opening / closing operation time (Steps S9, S16) is smaller than the determination time t5 (the third predetermined time) (Step S17), the processing unit 102 determines that it is a mismeasurement and does not perform subsequent data processing (measurement value storage, transmission, etc.). Note that when the measurement time t3 - t0 is larger than the determination time t5, the processing unit 102 treats it as a normal measurement.

[0083] Note that the processing unit 102 sets the third predetermined time t5 to, for example, be greater than the assumed operating time of the circuit breaker state diagnosis device 100 > t5.

[0084] As described above, when the noise is caused by the main circuit, the processing unit 102 determines that it is a false determination if the measured opening / closing operation time of the auxiliary switch of the circuit breaker is shorter than the determination time set from the assumed operation time of the circuit breaker, and determines that it is a correct determination if the measured opening / closing operation time of the auxiliary switch of the circuit breaker is longer than the determination time set from the assumed operation time of the circuit breaker.

[0085] As described above, in the present embodiment, it is detected that the state of the contact of the auxiliary switch of the circuit breaker has reversed, the detected time is used as a provisional measurement value, and if the state of the contact has not reversed after a predetermined time from the detected time, the provisional measurement value is reset, and if the state of the contact has reversed after a predetermined time from the detected time, the provisional measurement value is determined as the time when the contact has reversed.

[0086] Accordingly, according to the present embodiment, by using an algorithm for discriminating and eliminating this noise, false determination can be prevented and the accuracy of the measured value can be improved.

[0087] Note that a program for realizing all or part of the functions of the circuit breaker state diagnosis apparatus 100 according to the present invention may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to perform all or part of the processing performed by the circuit breaker state diagnosis apparatus 100. Here, the "computer system" is assumed to include hardware such as an OS and peripheral devices. Further, the "computer system" also includes a WWW system having a homepage providing environment (or display environment). Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or the like, or a storage device such as a hard disk incorporated in a computer system. Furthermore, the "computer-readable recording medium" also includes a volatile memory (RAM) inside a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line, and that holds the program for a certain period of time.

[0088] Also, the above program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the "transmission medium" for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) like the Internet or a communication line (communication wire) like a telephone line. Further, the above program may be for realizing a part of the functions described above. Furthermore, it may be a so-called differential file (differential program) that can realize the functions described above in combination with a program already recorded in the computer system.

[0089] As described above, the embodiments for carrying out the present invention have been described using the embodiments, but the present invention is not limited to such embodiments at all, and various modifications and substitutions can be made without departing from the gist of the present invention.

Explanation of Reference Numerals

[0090] 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... Tripping coil, 7... Closing coil, 9... Interrupting device, 100... Circuit breaker state diagnosis device, 20... External operation unit, R1, R2... Resistor, 101... Wave shaping circuit, 102... Processing unit, 103... Display unit, 104... Operation unit, 105... Timing unit, 106... Storage unit, 107... Output unit, 108... Command acquisition unit, 1021... Contact state detection unit, 1022... Current information acquisition unit, 1023... Noise determination unit

Claims

1. A contact state detection unit that detects that the state of the contact of the auxiliary switch of the circuit breaker has reversed; A processing unit that uses the detected time as a provisional measurement value, determines that it is noise if the state of the contact has not reversed after a predetermined time from the detected time, and resets the provisional measurement value, and if the state of the contact has reversed after the predetermined time from the detected time, determines the provisional measurement value as the time when the contact reversed; A circuit breaker state diagnosis device comprising:

2. After an opening / closing command is issued to the auxiliary switch, the processing unit starts detecting the state of the contact, and uses the time when the contact first reverses after the start of detecting the state of the contact of the auxiliary switch based on a threshold value as the provisional measurement value. The circuit breaker state diagnosis device according to claim 1.

3. After an opening / closing command is issued to the auxiliary switch, the processing unit starts detecting the state of the contact, and uses, as the provisional measurement value, the reversal times that are continuously detected every predetermined time within a predetermined time from the time when the contact first reverses after the start of detecting the state of the contact of the auxiliary switch based on a threshold value and for which no reversal is detected within a predetermined time after the detection. The circuit breaker state diagnosis device according to claim 1.

4. The processing unit starts detecting the state of the contact, and uses the time when the contact first reverses after the start of detecting the state of the contact of the auxiliary switch based on a threshold value as the first provisional measurement value, and uses, as the second provisional measurement value, the reversal times that are continuously detected every predetermined time within a predetermined time from the time when the contact first reverses and for which no reversal is detected within a predetermined time after the detection. If the time difference between the first provisional measurement value and the second provisional measurement value is shorter than a determination time, it is determined that there is a false determination, and if the time difference is longer than the determination time, it is determined that there is a correct determination. The circuit breaker state diagnosis device according to claim 1.

5. The determination time is less than the operating time of the circuit breaker state diagnosis device and greater than the noise time during which assumed noise continues. The circuit breaker state diagnosis device according to claim 4.

6. The contact state detection unit detects that the state of the contact of the auxiliary switch of the circuit breaker has reversed, The processing unit uses the detected time as a provisional measurement value, determines that it is noise if the state of the contact has not reversed after a predetermined time from the detected time, and resets the provisional measurement value, and if the state of the contact has reversed after the predetermined time from the detected time, determines the provisional measurement value as the time when the contact reversed. Circuit breaker state diagnosis method.

7. causing a computer to detect that the state of the contact of the auxiliary switch of the circuit breaker has reversed, use the detected time as a provisional measurement value, determine that it is noise if the state of the contact has not reversed after a predetermined time from the detected time and reset the provisional measurement value, and if the state of the contact has reversed after the predetermined time from the detected time, determine the provisional measurement value as the time when the contact reversed. Program.

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