JP4199378B2 - Plug or outlet - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a detection method of a short circuit, particularly a detection method of a short circuit due to a code short circuit / tracking phenomenon, a circuit interruption method that interrupts an electric circuit using the method, an alarm output method that outputs an alarm, and a circuit interruption method thereof. It relates to a plug or outlet using an alarm output method.
[0002]
[Prior art]
As shown in FIG. 1, the circuit breaker using the short circuit detection method and the circuit breaker is a trip unit which is a drive unit by a drive signal from the trip circuit 7 when an overcurrent flows through the electric circuit 10. The coil 8 is operated to open the contact 9. In order to trip the contact 9 by combining an electronic circuit, the short circuit detection method in FIG. 1 and the circuit breaker using the method detect the current of the electric circuit 10 with the current transformer 1, and the current-voltage After the conversion circuit 2 converts it to a voltage value, it converts it to a digital value (absolute value) by the A / D conversion circuit 4 inside the microcomputer 11 and integrates the digital value for a predetermined time by the integration circuit 5. When the value exceeds a predetermined reference value, a trip signal is output from the shut-off output circuit 6 to the trip circuit 7 to shut off the electric circuit.
[0003]
[Prior art issues]
However, the conventional techniques described above have the following disadvantages.
[0004]
The conventional circuit breaker shown in FIG. 1 integrates a current value for a predetermined time in the integrating circuit 5, and therefore detects a relatively low value of an accident current represented by a short circuit current due to a tracking phenomenon. It is necessary to keep the predetermined reference value small, but due to the inrush current of home appliances, if the reference value is made smaller than a certain value, an erroneous interruption occurs and it is difficult to detect a low accident current.
[0005]
In addition, when the circuit breaker shown in FIG. 1 detects a short circuit due to a cord short circuit / tracking phenomenon, the circuit breaker operates to break at the circuit breaker portion. When a circuit, such as a lighting circuit, was connected in parallel, the power supply to circuits other than the outlet was cut off even though the accident occurred at a specific outlet.
[0006]
[Problems to be solved by the invention]
Therefore, the present invention has been made in view of such a reason, it does not operate on the electric current waveform of home appliances, and a short-circuit detection method that reliably detects a short-circuit current due to a cord short-circuit or tracking phenomenon with a low accident current value, And the circuit interruption method using the detection method, the alarm output method, and the necessary minimum electric circuit that is the place where the short circuit occurs due to the cord short circuit or tracking phenomenon by incorporating the method into the outlet or plug The problem is to provide plugs and outlets that can shut off the power.
[0007]
[Means for Solving the Problems]
In order to solve the problem, claim 1 includes a current transformer for detecting a current flowing in an electric circuit, a current-voltage conversion circuit for converting an alternating current output from the current transformer into an alternating voltage, and the alternating voltage. A rectifying circuit for converting the pulsating voltage into a pulsating voltage, an A / D converting circuit for converting the pulsating voltage into a digital voltage value every predetermined time width of several milliseconds or less, and a half wave of a commercial frequency The judgment value output from the arithmetic circuit every unit time corresponding to the length is stored in the register circuit with the judgment value U for a new past T, where T is a number of 10 or more, and the digital voltage An arithmetic circuit that processes the value, adds the determination value U in the arithmetic circuit according to the processing result, outputs the determination value U in the arithmetic circuit, and simultaneously clears the determination value U in the arithmetic circuit; , Inside the register circuit every predetermined unit time A register circuit that always stores the latest plurality of determination values U by discarding the oldest determination value U and simultaneously reading and storing the newest determination value U output from the arithmetic circuit, and stored in the register circuit Using the cutoff output circuit that compares the threshold value B with the total of the past determination values U for the past T, the register circuit stores each predetermined unit time corresponding to the half-wave length of the commercial frequency. In the short-circuit detection method in which the cutoff output circuit outputs a detection signal when the sum of the determination values U for the past T is greater than the threshold value B, the detection signal of the cutoff output circuit of the short-circuit detection method is used as the detection signal. A trip circuit that outputs a drive signal to the trip coil and a contact 9 that cuts off the electric circuit, outputs a detection signal of the cut-off output circuit to the trip circuit, receives the detection signal, and trips Times It provides a plug incorporating a circuit breaking method of blocking the path and opening the contacts 9 outputs a driving signal to the trip coil.
[0008]
Further, according to a second aspect of the present invention, there is provided a current transformer for detecting a current flowing through an electric circuit, a current-voltage conversion circuit for converting an alternating current output from the current transformer into an alternating voltage, and a rectified current by rectifying the alternating voltage. A rectifier circuit that converts the voltage into a voltage; an A / D converter circuit that converts the pulsating voltage into a digital voltage value every predetermined time width of several milliseconds or less; and a unit corresponding to a half-wave length of a commercial frequency The determination value output from the arithmetic circuit every time, T is a number of 10 or more, the determination value U for the past past T is always stored in the register circuit, the digital voltage value is processed, An arithmetic circuit that adds the determination value U in the arithmetic circuit according to the result, outputs the determination value U in the arithmetic circuit, and simultaneously clears the determination value U in the arithmetic circuit, and the predetermined unit time The oldest judgment value U in the register circuit every time A register circuit that always stores the latest plurality of determination values U by reading and storing the latest determination value U output from the arithmetic circuit simultaneously with the discarding, and the past T pieces of data stored in the register circuit Using a cutoff output circuit that compares the sum of each determination value U with a threshold value B, the past T pieces stored in the register circuit every predetermined unit time corresponding to the half-wave length of the commercial frequency In the short-circuit detection method in which the shutoff output circuit outputs a detection signal when the sum of the determination values U of each is greater than the threshold value B, the shutoff output circuit includes an alarm circuit that outputs an alarm in response to the detection signal of the shutoff output circuit. The circuit is provided with a plug incorporating an alarm output method for receiving an alarm signal to the outside in response to a detection signal of the cutoff output circuit.
[0009]
Further, according to a ninth aspect of the present invention, there is provided a current transformer for detecting a current flowing in the electric circuit, a current-voltage conversion circuit for converting an alternating current output from the current transformer into an alternating voltage, and a rectified current by rectifying the alternating voltage. A rectifier circuit that converts the voltage into a voltage; an A / D converter circuit that converts the pulsating voltage into a digital voltage value every predetermined time width of several milliseconds or less; and a unit corresponding to a half-wave length of a commercial frequency The determination value output from the arithmetic circuit every time, T is a number of 10 or more, the determination value U for the past past T is always stored in the register circuit, the digital voltage value is processed, An arithmetic circuit that adds the determination value U in the arithmetic circuit according to the result, outputs the determination value U in the arithmetic circuit, and simultaneously clears the determination value U in the arithmetic circuit, and the predetermined unit time The oldest judgment value U in the register circuit every time A register circuit that always stores the latest plurality of determination values U by reading and storing the latest determination value U output from the arithmetic circuit simultaneously with the discarding, and the past T pieces of data stored in the register circuit Using a cutoff output circuit that compares the sum of each determination value U with a threshold value B, the past T pieces stored in the register circuit every predetermined unit time corresponding to the half-wave length of the commercial frequency In the short-circuit detection method in which the shut-off output circuit outputs a detection signal when the sum of the determination values U is greater than the threshold value B, the short-circuit detection A trip circuit that outputs a drive signal to the trip coil in response to the detection signal of the shut-off output circuit of the output method and a contact 9 that shuts off the electric circuit, and outputs the detection signal of the shut-off output circuit to the trip circuit In response to the detection signal, the trip circuit provides an outlet incorporating a circuit breaking method that outputs a drive signal to the trip coil to open the contact 9 to cut off the electric circuit.
[0010]
Further, the present invention provides a current transformer that detects a current flowing through an electric circuit, a current-voltage conversion circuit that converts an alternating current output from the current transformer into an alternating voltage, and a rectified current by rectifying the alternating voltage. A rectifier circuit that converts the voltage into a voltage; an A / D converter circuit that converts the pulsating voltage into a digital voltage value every predetermined time width of several milliseconds or less; and a unit corresponding to a half-wave length of a commercial frequency The determination value output from the arithmetic circuit every time, T is a number of 10 or more, the determination value U for the past past T is always stored in the register circuit, the digital voltage value is processed, An arithmetic circuit that adds the determination value U in the arithmetic circuit according to the result, outputs the determination value U in the arithmetic circuit, and simultaneously clears the determination value U in the arithmetic circuit, and the predetermined unit time The oldest judgment value inside the register circuit every time At the same time that the latest judgment value U output from the arithmetic circuit is read and stored, and a register circuit that always stores the latest plurality of judgment values U, and the past T stored in the register circuit Using the cutoff output circuit that compares the sum of the determination values U and the threshold value B, the past T pieces stored in the register circuit for each predetermined unit time corresponding to the half-wave length of the commercial frequency In the short-circuit detection method in which the cutoff output circuit outputs a detection signal when the sum of the determination values U of the minute exceeds the threshold B, the cutoff output circuit includes an alarm circuit that outputs a warning in response to the detection signal of the cutoff output circuit, The alarm circuit provides an outlet that incorporates an alarm output method for receiving an alarm signal to the outside in response to the detection signal of the shutoff output circuit.
[0011]
Further, claim 3 is an arithmetic circuit according to claim 1 or claim 2,Further, claim 11 is an arithmetic circuit according to claim 9 or claim 10,If the digital voltage value exceeds the threshold A during a predetermined unit time corresponding to the half wave length of the commercial frequency, the judgment value U inside the arithmetic circuit is added. Providing a way.
[0012]
Further, claim 4 is an arithmetic circuit according to claim 1 or claim 2, whereinA twelfth aspect of the present invention provides an arithmetic circuit according to the ninth or tenth aspect of the present invention.Of the three consecutive digital voltage values converted into digital voltage values every time width of several milliseconds or less, the second digital voltage value is smaller than the other two digital voltage values, and the second digital voltage value When the magnitude of the voltage value is larger than the threshold value C, a method of adding the determination value U inside the arithmetic circuit is provided.
[0013]
Further, claim 5 is an arithmetic circuit according to claim 1 or claim 2, whereinFurther, claim 13 is an arithmetic circuit according to claim 9 or claim 10,For each predetermined unit time corresponding to the half-wave length of the commercial frequency, the maximum value of the digital voltage value within the unit time is output to the register circuit, and the register circuit outputs the maximum value of the arithmetic circuit for each unit time. When the maximum value of the digital voltage value is read and stored, and the difference between the maximum value and the minimum value is greater than the threshold value D in at least the last five digital voltage values stored in the register circuit, The determination value U is added.
[0014]
Further, a sixth aspect of the present invention is the determination means according to the first or second aspect,Further, claim 14 is the determination means according to claim 9 or 10, whereinThe latest digital voltage value stored in the register circuit every predetermined unit time corresponding to the half wave length of the commercial frequency, and the second to at least fifth new digital voltage value stored in the register circuit When the difference from the maximum value is larger than the threshold value E and smaller than the threshold value F, a method of adding the determination value U inside the arithmetic circuit is provided.
[0015]
Further, claim 7 is an arithmetic circuit according to claim 1 or claim 2, whereinFurther, claim 15 is an arithmetic circuit according to claim 9 or claim 10,The second digital voltage value is smaller than the other two digital voltage values among the three consecutive digital voltage values converted into digital voltage values every time width of several milliseconds or less, and the second digital voltage. The maximum value of the digital voltage value of the arithmetic circuit is read and stored in a register every predetermined unit time corresponding to the first condition that the magnitude of the value is larger than the threshold C and the half wave length of the commercial frequency. At the same time, the second condition that the difference between the maximum value and the minimum value is greater than the threshold value D in at least the last five digital voltage values stored in the register circuit, and the latest condition stored in the register circuit. The difference between the maximum digital voltage value and the maximum value of the second to at least fifth new digital voltage value stored in the register circuit is larger than the threshold value E and smaller than the threshold value F. Among the third conditions, when all of the first to third conditions are satisfied, a numerical value such that the sum of the past determination values U stored in the register circuit is larger than the threshold value B is calculated. A method of substituting into the internal determination value U is provided.
[0016]
Further, according to an eighth aspect of the present invention, the method of adding the judgment value U in the arithmetic circuit is selectively combined with all of the third to seventh aspects or the third to seventh aspects.
We provide a way to make them hold.
[0017]
Further, according to a sixteenth aspect of the present invention, there is provided a method of selectively combining all of the eleventh to fifteenth aspects or the eleventh to fifteenth aspects of the method of adding the determination value U in the arithmetic circuit. Yes.
[0018]
[Action]
Claim 1And claim 9By appropriately processing the digital voltage value output from the A / D conversion circuit by the arithmetic circuit and outputting the determination value U by the method described above, the total value of the plurality of determination values U is compared with the threshold value B. , The load current of home appliances and the short-circuit current due to the low current value that flows when a short-circuit due to a cord short-circuit or tracking phenomenon can be distinguished and detected. It is possible to block only the minimum necessary electric circuit on the side, or to block only the necessary minimum electric circuit on the load device connection side of the outlet.
[0019]
Claim 2And claim 10By appropriately processing the digital voltage value output from the A / D conversion circuit by the arithmetic circuit and outputting the determination value U by the method described above, the total value of the plurality of determination values U is compared with the threshold value B. , The load current of home appliances and the short-circuit current due to the low current value that flows at the time of a short-circuit due to a cord short-circuit or tracking phenomenon can be distinguished and detected. The alarm can be output limited to the minimum necessary electric circuit on the side, or the alarm can be output limited to the minimum necessary electric circuit on the load device connection side of the outlet.
[0020]
Claim 3And claim 11When the transition from the inrush current waveform at the time of power input to a home appliance with a similar current waveform to the steady current waveform is compared with the short-circuit current waveform due to the cord short-circuit, the short-circuit current waveform due to the cord short-circuit However, it is possible to determine a cord short-circuit from the feature that a current higher than the steady-state current waveform of home appliances is continuously generated.
[0021]
Claim 4And claim 12Using the method described in, pay attention to the second magnitude of three consecutive digital voltage values, even if the short-circuit current waveform due to the tracking phenomenon is similar to the current waveform with noise superimposed on the load current waveform of home appliances. By doing so, it becomes possible to distinguish the load current waveform of a household electrical appliance from the short circuit waveform by a tracking phenomenon.
[0022]
Claim 5And claim 13Using the method described in the above, the load current waveform of the home appliance is distinguished from the short-circuit waveform due to the tracking phenomenon by using the fact that the fluctuation range of the short-circuit current due to the tracking phenomenon is larger than that of the load current of the home appliance. It becomes possible.
[0023]
Claim 6And claim 14By utilizing the fact that the fluctuation range of the short-circuit current due to the tracking phenomenon is smaller than the fluctuation range of the load current when the household appliance is stopped by the method described in, the short-circuit due to the load current and the tracking phenomenon when the household appliance is stopped The current can be distinguished.
[0024]
Claim 7And claim 15When a plurality of waveforms peculiar to the short-circuit current due to the tracking phenomenon are detected by the method described in the above, the sum of the past determination values U stored in the register circuit is larger than the threshold value B in the determination value U of the arithmetic circuit. By substituting a simple numerical value, it can be determined that a short circuit due to the tracking phenomenon has occurred in a short time.
[0025]
Claim 8And claim 16By the method described in the above, it is possible to more reliably detect a short circuit due to a code short circuit / tracking.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
[0027]
FIG. 2 shows the first and second aspects of the present invention., Claim 9 and claim 10Explanatory drawing of the short circuit detection method in FIG. In FIG. 2, a trip circuit is provided for the short-circuit detection method including the current transformer 1, the current-voltage conversion circuit 2, the rectification circuit 3, the A / D conversion circuit 4, the arithmetic circuit 12, the cutoff output circuit 6, and the register circuit 13. 7, a tripping coil 8 and a contact 9.
[0028]
Although the electric circuit 10 shows the case of a single-phase two-wire system, it is not particularly limited to the single-phase two-wire system. Further, the contact switching device including the tripping coil 8 and the contact 9 uses a circuit breaker or a relay.
[0029]
The current transformer 1 detects an electric current flowing through the electric circuit 10 and outputs an alternating current. The current transformer 1 detects a current waveform as shown in FIG. 4, for example.
[0030]
The current-voltage conversion circuit 2 converts the alternating current output from the current transformer 1 into an alternating voltage, and specifically converts it into a voltage value via a resistor.
[0031]
In the rectifier circuit 3, by rectifying the output voltage of the current-voltage conversion circuit 2 into a waveform as shown in FIG. 5 using a diode or the like, the monitoring voltage range can be reduced to half that when not rectified, and A / D conversion is performed. The resolution of the digital voltage value after digitizing the input voltage of the circuit 4 can be increased.
[0032]
Next, the inside of the microcomputer 11 will be described. The microcomputer 11 includes an A / D conversion circuit 4, an arithmetic circuit 12, a register circuit 13, and a cutoff output circuit 6.
[0033]
The A / D conversion circuit 4 divides the output voltage of the rectifier circuit 3 by a predetermined time width of several milliseconds or less and converts it into a digital voltage value. For example, the output voltage is digitized every 1 msec which is a sampling time.
[0034]
When the maximum input voltage of the A / D conversion circuit 4 is 5 V and the resolution of digital conversion is 8 bits, the output of the A / D conversion circuit 4 is 0 when 0 V, 127 and 5 V when 2.5 V. Time becomes 255. Here, when the current-voltage conversion circuit is adjusted so that the 1-bit current value at the time of A / D conversion corresponds to 1 A, the A / D conversion circuit 8 measures the current waveform from 0 A to +255 A. It becomes possible. Further, the microcomputer 11 incorporating the A / D conversion circuit 4 may be used.
[0035]
The arithmetic circuit 12 processes a digital voltage value generated per unit time corresponding to a half wave length of the commercial frequency, and adds a determination value U inside the arithmetic circuit 12 according to the processing result.
[0036]
The register circuit 13 discards the oldest judgment value U every unit time, and at the same time reads and stores the newest judgment value U output from the arithmetic circuit 12, and preferably sets T to a number of 10 or more. A new past T judgment values U are always stored.
[0037]
Further, the number T of past determination values U to be stored in order to increase the determination accuracy is preferably 10 or more, but it is preferable to store as many determination values U as possible according to the memory capacity inside the microcomputer.
[0038]
The shut-off output circuit 6 reads out each judgment value U stored in the register every unit time, obtains a sum, determines that a short circuit has occurred when the sum exceeds the threshold B, and detects the detection signal. Output.
[0039]
In the short-circuit detection method described above, the digital voltage value output from the A / D conversion circuit is processed by the arithmetic circuit 12 and converted into the determination value U, compared with the conventional method of performing the integration type determination according to FIG. Since the judgment value U stored in the circuit 13 is summed by the interruption circuit 6 and compared with the threshold value B, the judgment value U can be weighted by capturing the characteristics of the current waveform in the arithmetic circuit. Thereby, the load current and the accident current of the home appliance can be distinguished. The rectifier circuit 3 can be omitted. In that case, the digital voltage value that is the output of the A / D conversion circuit is output as both positive and negative, and may be converted into an absolute value thereafter.
[0040]
Next, claim 3 of the present invention.And claim 11Examples of Description will be made based on the block diagram of FIG. 2 and the waveform at the time of a cord short circuit as shown in FIG. This claim 3And claim 11Is an embodiment of the arithmetic circuit 12, and the arithmetic circuit 12 compares the digital voltage value generated per unit time corresponding to the length of half wave of the commercial frequency with the threshold value A, and the digital voltage If there is a value larger than the threshold A, the determination value U in the arithmetic circuit 12 is added. In the adding method, the magnitude of the digital voltage value generated per unit time is compared with the threshold value A, and the number of times that the digital voltage value is larger than the threshold value A may be added to the determination value U. The digital voltage value generated per unit time is compared with the threshold A, and if the digital voltage value is larger than the threshold A, 1 may be added to the determination value U. . FIG. 6 shows an example of the latter addition method.
[0041]
Regarding the set value of the threshold B with respect to the sum of the current threshold A and the past judgment value U of the register circuit, a numerical value corresponding to the magnitude of the current that operates when the cord is short-circuited and does not malfunction due to the inrush current of the home appliance Set. For example, the current threshold A can be arbitrarily set within a range not exceeding T, and the current B is about 100 A.
[0042]
The above processing will be described by way of a specific example. For example, in the case of a cord short-circuit waveform as shown in FIG. 6, the half-wave waveform exceeding the threshold A current value in the T half-wave waveforms Assuming that 1 is added to the judgment value U, the total of the past T judgment values U stored in the register circuit is equal to the threshold value B, so that the cutoff output circuit judges that a code short circuit has occurred. . Thereby, it is possible to discriminate between a waveform that gradually decreases from a large current due to an inrush current or the like of a home appliance to a steady current, and a case where a short circuit current that is not large up to the inrush current continuously flows, such as a cord short circuit.
[0043]
Next, claim 4 of the present invention.And claim 12Examples of Description will be made based on the block diagram of FIG. 2, the load current waveform of the home appliance of FIG. 7, and the short-circuit current waveform due to the tracking phenomenon of FIG. This claim 4And claim 12Is an embodiment of the arithmetic circuit 12, and the arithmetic circuit 12 updates the digital voltage value one by one every predetermined time width, and always stores three consecutive digital voltage values.
[0044]
Of the three consecutive digital voltage values, a waveform in which the second digital voltage value is smaller than the other two digital voltage values frequently appears in the short-circuit current waveform due to the tracking phenomenon, and is distinctively distinguished from other waveforms. However, it is difficult to distinguish when noise is superimposed on the current waveform of a home appliance that has an inverter.
[0045]
However, by adding a determination condition as to whether or not the second digital voltage value is larger than the threshold value C, a household electrical appliance having a short-circuit current waveform due to the tracking phenomenon shown in FIG. 8 and an inverter as shown in FIG. Can distinguish when noise is superimposed on the current waveform.
[0046]
When the magnitude of the digital voltage value is larger than the threshold value C in the second arithmetic circuit, it is determined that a waveform short-circuiting due to the tracking phenomenon as shown in FIG. Is added. Further, the interruption output circuit 6 reads out each determination value U stored in the register as needed to obtain the sum, and when the sum exceeds the threshold B, it is determined that a short circuit due to the tracking phenomenon has occurred.
[0047]
The setting value of the threshold C shown in FIGS. 7 and 8 corresponds to the magnitude of current that operates with a short-circuit current due to the tracking phenomenon shown in FIG. 8 and does not malfunction due to home appliances having the inverter shown in FIG. Set the numerical value to be used. For example, the threshold C is set to a numerical value such as 20A. There is an upper limit to the load capacity of the household electrical appliance having an inverter, and therefore an upper limit can be set for the threshold value C. By appropriately selecting the threshold value C, it is possible to distinguish between a short-circuit current waveform due to a normal tracking phenomenon and a current waveform of a home appliance having an inverter.
[0048]
Next, the claims of the present invention5 and claim 13Examples of Description will be made based on the block diagram of FIG. 3, the load current of the home appliance of FIG. 9, and the short-circuit current due to the tracking phenomenon of FIG. This claim 5And claim 13Is an embodiment of the arithmetic circuit 12, and causes the register circuit 13 to output the maximum value of the digital voltage value within the unit time for each unit time, and the register circuit 13 is the latest of the arithmetic circuit every predetermined unit time. The maximum value of the digital voltage value is read and stored, and at the same time, the maximum value of the oldest digital voltage value is discarded, and the latest maximum value of digital voltage values for the past S is always stored.
[0049]
When the difference between the maximum value and the minimum value of the first to at least fifth digital voltage values stored in the register circuit 13 is larger than the threshold value D, the arithmetic circuit 12 determines the determination value of the arithmetic circuit 12. Add U. Further, the interruption output circuit 6 reads out each determination value U stored in the register as needed to obtain the sum, and when the sum exceeds the threshold B, it is determined that a short circuit due to tracking has occurred.
[0050]
Note that the threshold value D is larger during fluctuation of the short circuit current due to the tracking phenomenon as shown in FIG. 10 than in the fluctuation range of the maximum value of the load current of the home appliance as shown in FIG. A numerical value corresponding to the magnitude of a current that operates with a short-circuit current due to such a tracking phenomenon and does not malfunction due to a current of a home appliance as shown in FIG. 9 is set. For example, the threshold value D is set to a current value of about 10 A, which is larger than the amount of change in load current during normal use of the home appliance. Further, it is necessary to store more than a dozen determination values for the past S, and it is preferable to increase the number that can be stored in accordance with the memory capacity inside the microcomputer.
[0051]
Next, claim 6 of the present invention.And claim 14Examples of Description will be made based on the block diagram of FIG. 2, the load current waveform of the home appliance of FIG. 11, and the current waveform by tracking shown in FIG. This claim 6And claim 14Is an embodiment of the arithmetic circuit 12, and the latest digital voltage value stored in the register circuit 13 and the maximum value among the second to at least fifth new digital voltage values stored in the register circuit. When the difference is larger than the threshold value E and smaller than the threshold value F, it is determined that a short-circuit current due to the tracking phenomenon as shown in FIG. 12 has occurred, and the determination value U of the arithmetic circuit 12 is added. Further, the interruption output circuit 6 reads out each determination value U stored in the register as needed to obtain the sum, and when the sum exceeds the threshold B, it is determined that a short circuit due to tracking has occurred.
[0052]
The threshold value E can be set for the reason described with reference to FIGS. 9 and 10, and the setting value of the threshold value F is larger than the large change amount of the load current when the home appliance is stopped as shown in FIG. 11. 12 is smaller in the amount of change in the short-circuit current due to the tracking phenomenon as shown in FIG. 12, so that it operates with the short-circuit current due to the tracking phenomenon as shown in FIG. It is possible to set a digital voltage value corresponding to the magnitude of the current that does not malfunction due to such an operation.
[0053]
Next, claim 7 of the present invention.And claim 15Examples of This will be described with reference to FIG. This claim 7And claim 15Is an embodiment of the arithmetic circuit 12, and claim 4And claim 12The second digital voltage value among the three consecutive digital voltage values described in the above item 1 is smaller than the other two digital voltage values, and the second digital voltage value is larger than the threshold value C. And the condition of claim 5And claim 13A second condition that a difference between the maximum values of the first to at least fifth most new digital voltage values stored in the register circuit described in the above item is greater than a threshold value D, andAnd claim 14The difference between the latest digital voltage value stored in the register circuit described in the above and the maximum value among the second to at least fifth new digital voltage values stored in the register circuit is larger than the threshold E and the threshold F If all of the third condition of less than is satisfied, it means that a number of unique phenomena that occurred during the short circuit due to the tracking phenomenon have been detected, and the possibility that a short circuit due to the tracking phenomenon has occurred is very high. The arithmetic circuit 12 has a function of substituting the arithmetic circuit U with a numerical value such that the total value of the past determination values U stored in the register circuit by the cutoff circuit 6 is larger than the threshold value B. In that case, when the interruption output circuit 6 reads out each determination value U stored in the register and obtains the sum at any time, the sum is larger than the threshold value B, and a short circuit due to tracking immediately occurs. Judgment can be made.
[0054]
Next, an embodiment of claim 8 of the present invention will be shown. According to the eighth aspect of the present invention, all of the methods according to the third to seventh aspects are performed for the calculation of the determination value U of the arithmetic circuit 12 or selectively performed in combination. In addition, it is possible to detect a short circuit due to a cord short circuit and a tracking phenomenon.
[0055]
Next, an embodiment of claim 16 of the present invention will be shown. The sixteenth aspect is such that all of the methods according to the eleventh to fifteenth aspects are performed for the calculation of the determination value U of the arithmetic circuit 12, or are selectively performed in combination. In addition, it is possible to detect a short circuit due to a cord short circuit and a tracking phenomenon.
[0056]
Next, the circuit interruption method in Claim 1 and Claim 9 of this invention is demonstrated based on FIG. FIG. 3 is a block diagram showing a configuration of a means for realizing a cutoff method when a short circuit occurs due to a cord short circuit / tracking phenomenon. The current transformer 1, a current-voltage conversion circuit 2, a rectifier circuit 3, and an A / D conversion. The circuit 4, the arithmetic circuit 12, the register circuit 13, and the cutoff output circuit 6 are the same as those in FIG. 2, and are provided with a trip circuit 7, a trip coil 8, and a contact 9. In this example, the detection signal from the interruption output circuit is output to the trip circuit, and upon receiving the detection signal, the trip circuit 7 outputs the drive signal to the trip coil 8 to cut off the electric circuit. it can.
[0057]
Next, an alarm output method in claims 2 and 10 of the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing a configuration of means for realizing an alarm output method when a short circuit occurs due to a code short circuit / tracking phenomenon. The current transformer 1, current-voltage conversion circuit 2, rectifier circuit 3, A / The D conversion circuit 4, the cutoff output circuit 6, the arithmetic circuit 12, and the register circuit 13 are the same as in FIG. 2, and the alarm circuit 17 is connected to the cutoff output circuit 6. This embodiment is a block diagram showing a configuration of means for realizing a method for outputting an alarm when a short circuit is detected due to a code short circuit / tracking phenomenon. By adding an alarm output circuit 17, a code short circuit and a tracking phenomenon are performed. An alarm can be output when a short circuit occurs.
[0058]
The alarm means of the alarm output circuit 17 may be provided with an alarm lamp display, audio output, or external contact output.
[0059]
Next, claims 1 and 2 of the present invention, Claim 9, claim 10Examples of This will be described with reference to FIGS. In this embodiment, a plug 19 or an outlet 16 is connected to the circuit shut-off method or the alarm output method described above, and by selectively incorporating either in the housing, the circuit can be short-circuited due to a cord short circuit or a tracking phenomenon. It is possible to provide a plug or an outlet capable of shutting off or outputting an alarm, and separating only an electric circuit in which an accident has occurred from other electric circuits to generate an interrupt or an alarm.
[0060]
【The invention's effect】
As described above, according to the first aspect of the present invention, the digital voltage value output from the A / D conversion circuit is appropriately processed by the arithmetic circuit to output the determination value U, and the total value of the plurality of determination values U is obtained. By comparing with the threshold value B, it is possible to distinguish and detect the load current of home appliances and the short-circuit current due to the low current value that flows at the time of the short-circuit due to the cord short-circuit or tracking phenomenon, and it was determined that the short-circuit due to the cord short-circuit / tracking occurred In this case, it becomes possible to cut off only the minimum necessary electric circuit on the load device connection side of the plug or outlet, and at the same time, it is possible to prevent an electrical fire due to a short circuit due to a cord short circuit or tracking phenomenon. It is possible to provide a plug that can secure other necessary power sources such as lighting.
[0061]
According to the invention of claim 2, as described above, according to the invention of claim 1, the digital voltage value output from the A / D conversion circuit is appropriately processed by the arithmetic circuit and the determination value U is output. In addition, by comparing the total value of the plurality of determination values U with the threshold value B, it is possible to distinguish and detect the load current of the home appliance and the short-circuit current due to the low current value that flows when the cord is short-circuited or short-circuited due to the tracking phenomenon. When it is determined that a short circuit has occurred due to a short circuit or tracking, an alarm can be output only to the minimum required circuit on the load device connection side of the plug or outlet. Thus, it is possible to provide a plug that can prevent an electric fire caused by the above and at the same time secure other necessary power sources such as lighting.
[0062]
According to the ninth aspect of the present invention, the digital voltage value output from the A / D conversion circuit is appropriately processed by the arithmetic circuit to output the determination value U, and the total value of the plurality of determination values U is compared with the threshold value B. By doing so, it is possible to distinguish and detect the load current of home appliances and the short-circuit current due to the low current value that flows when a short-circuit due to a cord short-circuit or tracking phenomenon. To the minimum necessary electric circuit on the load device connection side of the outlet It is possible to cut off only in a limited manner, and it is possible to prevent electrical fires due to short-circuiting due to cord short-circuiting or tracking phenomenon, etc., and at the same time provide an outlet that can secure other necessary power sources such as lighting it can.
[0063]
According to the invention of claim 10, as described above, according to the invention of claim 1, the digital voltage value output from the A / D conversion circuit is appropriately processed by the arithmetic circuit and the determination value U is output. In addition, by comparing the total value of the plurality of determination values U with the threshold value B, it is possible to distinguish and detect the load current of the home appliance and the short-circuit current due to the low current value that flows when the cord is short-circuited or short-circuited due to the tracking phenomenon. When it is determined that a short circuit has occurred due to a short circuit or tracking, it is possible to output an alarm only for the minimum necessary circuit on the load device connection side of the plug or outlet, such as a short circuit due to a cord short circuit or tracking phenomenon, etc. It is possible to provide an outlet that can prevent electric fire due to the light and at the same time secure other necessary power sources such as lighting.
[0064]
Claim 3And claim 11According to the invention of the present invention, when comparing the waveform at the time of transition from the inrush current waveform at the time of power supply input to a home appliance with a similar current waveform to the steady current waveform and the short-circuit current waveform due to the cord short-circuit, the short-circuit current waveform due to the cord short-circuit Therefore, it is possible to provide a plug or an outlet capable of determining a cord short-circuit from the feature that a higher current than a steady-state current generated by a home appliance is continuously generated.
[0065]
Claim 4And claim 12According to the invention, even if noise is superimposed on the short-circuit current waveform due to the tracking phenomenon and the load current waveform of the home appliance, and the current waveform is similar, attention is paid to the second magnitude of the three consecutive digital voltage values. By doing so, it is possible to provide a plug or an outlet that can distinguish a load current waveform of a home appliance from a short-circuit waveform due to a tracking phenomenon.
[0066]
Claim 5And claim 13According to the invention, the load current waveform of the home appliance is distinguished from the short-circuit waveform due to the tracking phenomenon by utilizing the fact that the fluctuation width of the short-circuit current due to the tracking phenomenon is larger than that of the load current of the home appliance. A plug or outlet can be provided.
[0067]
Claim 6And claim 14According to the invention of the present invention, the short-circuit current fluctuation due to the tracking phenomenon is smaller than the fluctuation width of the load current when the home appliance stops. A plug or outlet can be provided that can distinguish the current.
[0068]
Claim 7And claim 15According to the invention, when a plurality of waveforms peculiar to the short-circuit current due to the tracking phenomenon are detected, the sum of the past determination values U stored in the register circuit is larger than the threshold value B in the determination value U of the arithmetic circuit. By substituting various numerical values, it is possible to provide a plug or an outlet that can determine that a short circuit due to the tracking phenomenon has occurred in a short time.
[0069]
Claim 8And claim 16According to the present invention, it is possible to provide a plug or an outlet that can more reliably detect a short circuit due to a cord short circuit / tracking.
[Brief description of the drawings]
FIG. 1 is a schematic circuit diagram of a method for interrupting an electronic circuit equipped with a conventional microcomputer.
FIG. 2 is a schematic circuit example of the present invention.
FIG. 3 shows an embodiment of the present invention.
FIG. 4 Example of current waveform
FIG. 5 shows an example of a voltage waveform obtained by rectifying the output voltage of the current-voltage conversion circuit 2 using a diode.
FIG. 6 shows an example of a cord short-circuit waveform
Fig. 7 Load current waveform of home appliances
[Figure 8] Short-circuit current waveform by tracking
[Fig. 9] Load current waveform of home appliances
[Figure 10] Short-circuit current waveform due to tracking
FIG. 11 shows the load current waveform of home appliances.
FIG. 12 Short-circuit current waveform by tracking
FIG. 13 shows a plug using a circuit interruption method or an alarm output method.
FIG. 14 shows an outlet using a circuit interruption method or an alarm output method.
[Explanation of symbols]
1 Current transformer
2 Current-voltage conversion circuit
3 Rectifier circuit
4 A / D conversion circuit
5 Integration circuit
6 contacts
7 Tripping circuit
8 Tripping coil
9 contacts
10 electric circuit
11 Microcomputer
12 Arithmetic circuit
13 Register circuit
14 Plug connector for wiring
15 relay
16 outlet
17 Alarm circuit
18 plugs
19 Plug blade

Claims (16)

A current transformer for detecting a current flowing in the electric circuit; a current-voltage conversion circuit for converting an alternating current output from the current transformer into an alternating voltage; and a rectifying circuit for rectifying the alternating voltage into a pulsating voltage. An A / D conversion circuit for converting the pulsating voltage into a digital voltage value every predetermined time width of several milliseconds or less, and the digital voltage value per unit time corresponding to a half-wave length of a commercial frequency. An arithmetic circuit that adds a judgment value U inside the arithmetic circuit according to the processing result, outputs a judgment value U inside the arithmetic circuit, and simultaneously clears the judgment value U inside the arithmetic circuit, and the unit The judgment value output from the arithmetic circuit every time, T is a number of 10 or more, the judgment value U for the past past T is always stored in the register circuit, and the oldest judgment in the register circuit is stored. At the same time the value U is discarded A register circuit that always stores the latest plurality of determination values U by reading and storing the latest determination value U output from the memory, and a total of the past T determination values U stored in the register circuit, A total of the past T judgment values U stored in the register circuit for each unit time corresponding to a half-wave length of the commercial frequency is constituted by a cutoff output circuit for comparing the threshold B. A tripping circuit that outputs a drive signal to the tripping coil in response to the detection signal of the shutoff output circuit of the short-circuit detection method in the short-circuit detection method in which the cutoff output circuit outputs a detection signal when the cutoff output circuit is larger than B; It consists of a contact 9 that cuts off the electric circuit, outputs the detection signal of the cut-off output circuit to the trip circuit, receives the detection signal, the trip circuit outputs a drive signal to the trip coil, and opens the contact 9 Extremely Plug, characterized in that incorporated a circuit breaking method of blocking the road. A current transformer for detecting a current flowing in the electric circuit; a current-voltage conversion circuit for converting an alternating current output from the current transformer into an alternating voltage; and a rectifying circuit for rectifying the alternating voltage into a pulsating voltage. An A / D conversion circuit for converting the pulsating voltage into a digital voltage value every predetermined time width of several milliseconds or less, and the digital voltage value per unit time corresponding to a half-wave length of a commercial frequency. An arithmetic circuit that adds a judgment value U inside the arithmetic circuit according to the processing result, outputs a judgment value U inside the arithmetic circuit, and simultaneously clears the judgment value U inside the arithmetic circuit, and the unit The judgment value output from the arithmetic circuit every time, T is a number of 10 or more, the judgment value U for the past past T is always stored in the register circuit, and the oldest judgment in the register circuit is stored. At the same time the value U is discarded A register circuit that always stores the latest plurality of determination values U by reading and storing the latest determination value U output from the memory, and a total of the past T determination values U stored in the register circuit, A total of the past T judgment values U stored in the register circuit for each unit time corresponding to a half-wave length of the commercial frequency is constituted by a cutoff output circuit for comparing the threshold B. In the short-circuit detection method in which the cutoff output circuit outputs a detection signal when it becomes larger than B, the cutoff output circuit comprises an alarm circuit that outputs an alarm in response to the detection signal of the cutoff output circuit, and the alarm circuit is a detection signal of the cutoff output circuit plug, characterized in that it incorporates the alarm output method for outputting an alarm to the outside in response to the. In the case where there is one in which the magnitude of the digital voltage value exceeds a threshold A during a unit time corresponding to a half wave length of a commercial frequency, the arithmetic circuit sets a determination value U inside the arithmetic circuit. plug of claim 1 or claim 2, characterized in adding. The arithmetic circuit has a second digital voltage value smaller than the other two digital voltage values among three consecutive digital voltage values converted into digital voltage values every time width of several milliseconds or less, and the second when the magnitude of the digital voltage value is greater than the threshold value C, plug according to claim 1 or claim 2, characterized in adding an internal decision value U of the operational circuit. The arithmetic circuit outputs the maximum value of the digital voltage value within the unit time to the register circuit every unit time corresponding to the half wave length of the commercial frequency, and the register circuit performs the operation every unit time. When the maximum value of the digital voltage value of the circuit is read and stored and at the same time the difference between the maximum value and the minimum value is greater than the threshold value D in at least the last five digital voltage values stored in the register circuit, the calculation is performed. claim 1 or plug according to claim 2, characterized in adding an internal decision value U of the circuit. The arithmetic circuit outputs a maximum value of a digital voltage value within a unit time corresponding to a half wave length of a commercial frequency to the register circuit, and the register circuit outputs the digital voltage value of the arithmetic circuit every unit time. The difference between the latest digital voltage value stored in the register circuit and the maximum value among the second to at least fifth new digital voltage values stored in the register circuit is If less than larger and the threshold value F than the threshold value E, plug according to claim 1 or claim 2, characterized in adding an internal decision value U of the operational circuit. The arithmetic circuit has a second digital voltage value smaller than the other two digital voltage values among three consecutive digital voltage values converted into digital voltage values every time width of several milliseconds or less, and The first condition that the magnitude of the second digital voltage value is larger than the threshold value C, and the maximum value of the digital voltage value of the arithmetic circuit for each unit time corresponding to the half-wave length of the commercial frequency is registered. And at the same time, the second condition that the difference between the maximum value and the minimum value is greater than the threshold value D in at least the last five digital voltage values stored in the register circuit, and is stored in the register circuit. Whether the difference between the digital voltage value, which is the latest maximum value, and the maximum value among the second to at least fifth new digital voltage values stored in the register circuit is greater than the threshold value E Among the third conditions that are smaller than the threshold value F, if all of the first to third conditions are satisfied, a numerical value by which the sum of the past determination values U stored in the register circuit is larger than the threshold value B, plug of claim 1 or claim 2, characterized in that assigned to the interior of the determination value U of the operational circuit. The addition method of the determination value U in the arithmetic circuit selectively includes all of claims 3 to 7 or claims 3 to 7. G. A current transformer for detecting a current flowing in the electric circuit; a current-voltage conversion circuit for converting an alternating current output from the current transformer into an alternating voltage; and a rectifying circuit for rectifying the alternating voltage into a pulsating voltage. An A / D conversion circuit for converting the pulsating voltage into a digital voltage value every predetermined time width of several milliseconds or less, and the digital voltage value per unit time corresponding to a half-wave length of a commercial frequency. An arithmetic circuit that adds a judgment value U inside the arithmetic circuit according to the processing result, outputs a judgment value U inside the arithmetic circuit, and simultaneously clears the judgment value U inside the arithmetic circuit, and the unit The judgment value output from the arithmetic circuit every time, T is a number of 10 or more, the judgment value U for the past past T is always stored in the register circuit, and the oldest judgment in the register circuit is stored. At the same time that the value U is discarded, A register circuit that always stores the latest plurality of determination values U by reading and storing the latest determination value U output from the memory, and a total of the past T determination values U stored in the register circuit, A total of the past T judgment values U stored in the register circuit for each unit time corresponding to a half-wave length of the commercial frequency is constituted by a cutoff output circuit for comparing the threshold B. A tripping circuit that outputs a drive signal to the tripping coil in response to the detection signal of the shutoff output circuit of the short-circuit detection method in the short-circuit detection method in which the cutoff output circuit outputs a detection signal when the cutoff output circuit is greater than B It consists of a contact 9 that cuts off the electric circuit, outputs the detection signal of the cut-off output circuit to the trip circuit, receives the detection signal, the trip circuit outputs a drive signal to the trip coil, and opens the contact 9 Extremely The circuit breaking method of blocking a road Outlet characterized by built-in. A current transformer for detecting a current flowing in the electric circuit; a current-voltage conversion circuit for converting an alternating current output from the current transformer into an alternating voltage; and a rectifying circuit for rectifying the alternating voltage into a pulsating voltage. An A / D conversion circuit for converting the pulsating voltage into a digital voltage value every predetermined time width of several milliseconds or less, and the digital voltage value per unit time corresponding to a half-wave length of a commercial frequency. An arithmetic circuit that adds a judgment value U inside the arithmetic circuit according to the processing result, outputs a judgment value U inside the arithmetic circuit, and simultaneously clears the judgment value U inside the arithmetic circuit, and the unit The judgment value output from the arithmetic circuit every time, T is a number of 10 or more, the judgment value U for the past past T is always stored in the register circuit, and the oldest judgment in the register circuit is stored. At the same time that the value U is discarded, A register circuit that always stores the latest plurality of determination values U by reading and storing the latest determination value U output from the memory, and a total of the past T determination values U stored in the register circuit, A total of the past T judgment values U stored in the register circuit for each unit time corresponding to a half-wave length of the commercial frequency is constituted by a cutoff output circuit for comparing the threshold B. In the short-circuit detection method in which the cutoff output circuit outputs a detection signal when it becomes larger than B, the cutoff output circuit comprises an alarm circuit that outputs an alarm in response to the detection signal of the cutoff output circuit, and the alarm circuit is a detection signal of the cutoff output circuit An outlet that features an alarm output method that outputs an alarm to the outside. In the case where there is one in which the magnitude of the digital voltage value exceeds a threshold A during a unit time corresponding to a half wave length of a commercial frequency, the arithmetic circuit sets a determination value U inside the arithmetic circuit. The outlet according to claim 9 or 10, characterized by adding. The arithmetic circuit has a second digital voltage value smaller than the other two digital voltage values among three consecutive digital voltage values converted into digital voltage values every time width of several milliseconds or less, 11. The outlet according to claim 9, wherein when the magnitude of the second digital voltage value is larger than the threshold value C, the determination value U inside the arithmetic circuit is added. The arithmetic circuit outputs the maximum value of the digital voltage value within the unit time to the register circuit every unit time corresponding to the half wave length of the commercial frequency, and the register circuit performs the operation every unit time. When the maximum value of the digital voltage value of the circuit is read and stored, and at the same time the difference between the maximum value and the minimum value is greater than the threshold value D in at least the last five digital voltage values stored in the register circuit, the calculation is performed. 11. The outlet according to claim 9, wherein a judgment value U inside the circuit is added. The arithmetic circuit outputs a maximum value of a digital voltage value within a unit time corresponding to a half wave length of a commercial frequency to the register circuit, and the register circuit outputs the digital voltage value of the arithmetic circuit every unit time. The difference between the latest digital voltage value stored in the register circuit and the maximum value among the second to at least fifth new digital voltage values stored in the register circuit is The outlet according to claim 9 or 10, wherein when the threshold value E is larger than the threshold value F and the threshold value F is smaller than the threshold value F, the judgment value U inside the arithmetic circuit is added. The arithmetic circuit has a second digital voltage value smaller than the other two digital voltage values among three consecutive digital voltage values converted into digital voltage values every time width of several milliseconds or less, and The first condition that the magnitude of the second digital voltage value is larger than the threshold value C, and the maximum value of the digital voltage value of the arithmetic circuit for each unit time corresponding to the half-wave length of the commercial frequency is registered. The latest stored in the register circuit at the same time Of at least the past five digital voltage values, the second condition that the difference between the maximum value and the minimum value is larger than the threshold value D, and the digital voltage value and the register circuit that are the latest maximum values stored in the register circuit 1 to 3 of the third conditions that the difference from the second to at least fifth largest digital voltage value stored in is greater than the threshold value E and smaller than the threshold value F. 10. When all of the above are satisfied, a numerical value in which the sum of the past determination values U stored in the register circuit is larger than the threshold value B is substituted for the determination value U inside the arithmetic circuit. The outlet according to claim 10. The method according to claim 9 or 10, wherein the calculation circuit includes a method for adding the judgment value U, wherein all of claims 11 to 15 or claim 11 to claim 15 are selectively combined. .

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