JP2009236608A - Insulation abnormality detection device and domestic electric appliance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulation abnormality detection device and a domestic electric appliance can detect an insulation abnormality with high detection accuracy by an inexpensive constitution, and control a load to prevent emission of smoke or fire caused by abnormal overheating when an insulation abnormality is generated. <P>SOLUTION: This device is equipped with a driving means 6 for controlling operation of a motor 3 connected electrically to a commercial power source 1 through a connection part 2; an insulation abnormality detection means 4 for detecting a current flowing in the connection part 2 at a sampling timing; and an insulation abnormality determination means 5 for detecting generation of a tracking phenomenon generated between electric paths of the connection part 2 from output from the insulation abnormality detection means 4, and determining an abnormality of an insulation state. The driving means 6 controls operation of the motor 3 corresponding to output from the insulation abnormality determination means 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an insulation abnormality detection device that detects an insulation state of a connection portion that electrically connects a power source and a load, and a home appliance having the insulation abnormality detection device.

  As a conventional detection of an insulation state, for example, “an ultrasonic sensor for detecting an ultrasonic wave accompanying a partial discharge of a diagnosis target connected to an AC system, and a specific frequency component of a detection signal of the ultrasonic sensor” A filter circuit for passing a signal; a detection circuit for detecting an output signal of the filter circuit; an integration circuit for integrating the output signal of the detection circuit; and twice the power supply frequency of the AC system from the output signal of the integration circuit An insulation abnormality diagnosis apparatus comprising an analysis circuit that extracts a signal of a frequency component of the above and extracts an insulation abnormality of the diagnosis target based on the extraction result has been proposed (for example, see Patent Document 1). .

JP-A-2005-147890 (Claim 1)

  When insulation abnormalities (hereinafter also referred to as “tracking phenomenon”) occur in connection parts such as terminal blocks, connectors, and soldered parts on printed circuit boards, heat and sparks are generated due to the tracking phenomenon. There is a risk of smoke or fire. For this reason, an insulation abnormality detection device that can accurately detect the occurrence of the tracking phenomenon is desired.

Conventionally, as an apparatus for diagnosing an insulation abnormality, an apparatus that captures an ultrasonic wave accompanying partial discharge with an acoustic sensor has been proposed. However, in this configuration, since it is necessary to provide an acoustic sensor, a filter circuit for extracting a specific signal, and the like, there is a problem in that the circuit configuration becomes complicated and the component cost increases.
In addition, since ultrasonic waves are used to detect the occurrence of partial discharge and the abnormal state of the connection part is not directly detected, there is a problem that the possibility of false detection is high and the detection accuracy is low. .

  The present invention has been made to solve the above-described problems, and can detect an insulation abnormality with a high detection accuracy and an inexpensive configuration. Also, an abnormal overheating when an insulation abnormality occurs is provided. An object of the present invention is to provide an insulation abnormality detection device and a home electric appliance capable of controlling a load so as to prevent smoke and fire due to the above.

  An insulation abnormality detection device according to the present invention includes a drive unit that controls operation of a load that is electrically connected to a power source via a connection part, and an insulation abnormality detection that detects a current flowing through the connection part at a predetermined sampling timing. And an insulation abnormality determination means for detecting an occurrence of a tracking phenomenon that occurs between the electrical paths of the connecting portion from an output of the insulation abnormality detection means and determining an abnormality in an insulation state, and the drive means includes the insulation abnormality The operation of the load is controlled according to the output of the judging means.

  According to the present invention, it is possible to detect an insulation abnormality with a high detection accuracy and an inexpensive configuration by determining an abnormality in the insulation state that occurs in the connecting portion and controlling the operation of the load in accordance with the determination. Also, the load can be controlled so as to prevent smoke and fire due to abnormal overheating when an insulation abnormality occurs.

Embodiment 1 FIG.
1 is a block configuration diagram of an insulation abnormality detection device according to Embodiment 1 of the present invention. In FIG. 1, the insulation abnormality detection device is composed of an insulation abnormality detection means 4, an insulation abnormality determination means 5, and a drive means 6, and is a load that is electrically connected to the commercial power source 1 via the connection unit 2. The operation of a certain motor 3 is controlled. Furthermore, the insulation abnormality detection means 4 includes a current detection means 41 for detecting a current supplied to the electric motor 3 through the connection portion 2, a rectification means 42 for rectifying the output of the current detection means 41, and a rectification means 42. And A / D conversion means 43 for detecting the output as a digital value. Further, the insulation abnormality determination means 5 determines the abnormality of the insulation state of the connecting portion 2 from the detection result of the A / D conversion means 43 and outputs the determination result to the drive means 6. The drive unit 6 is made of, for example, a triac and controls the electric motor 3 based on the output of the insulation abnormality determination unit 5.

  The connecting portion 2 is provided for electrically connecting the commercial power source 1 and the motor 3 by the terminals 21 and 22, such as a terminal block, a connector, a flat terminal, a closed end connector, a solder joint, etc. Composed.

In the first embodiment, the connecting portion 2 for connecting the electric motor 3 as shown in FIG. 1 will be described. However, the present invention is not limited to this, and the driving means 6 and the insulation abnormality detecting means 4 are mounted. The present invention can also be applied to the solder joints on the printed circuit board and other electrical paths (charging parts) to which the electric power of the commercial power source 1 is applied.
Details of the operation of the first embodiment having such a configuration will be described below with reference to FIGS.

  2 is a waveform diagram showing a commercial power supply waveform in Embodiment 1 of the present invention, FIG. 3 is a waveform diagram showing a detection waveform of an insulation abnormality detecting means in Embodiment 1 of the present invention, and FIG. FIG. 3B is a waveform diagram in which the current detection means 41 detects the current flowing through the connection portion 2 when there is no insulation abnormality, and FIG. 3B shows the current flowing through the connection portion 2 when there is an insulation abnormality. FIG. 3C is a waveform diagram in which the output of the current detection means 41 is rectified by the rectification means 42. FIG. 4 is a diagram showing the detection timing of the insulation abnormality detection means and the operation of the insulation abnormality judgment means in Embodiment 1 of the present invention. FIG. 4 (a) shows the output of the rectification means 42 by the A / D conversion means 43. FIG. 4B shows the detected value obtained by detecting the output of the rectifier 42 by the A / D converter 43, and FIG. 4C shows the current data of the detected value of the A / D converter 43. FIG. 4D is a diagram showing the amount of change that is the absolute value of the difference from the previous data and the insulation abnormality judgment level of the insulation abnormality judgment means 5, FIG. 4D is a diagram showing the judgment result of the insulation abnormality judgment means 5, and FIG. These are figures which show the driving | running state of the electric motor 3 which the drive means 6 controls by the determination result of the insulation abnormality determination means 5. FIG. Further, FIG. 5 is a diagram showing the configuration of the connecting portion and the relationship between the tracking resistance and the total current in Embodiment 1 of the present invention, and FIG. 5 (a) is for explaining the tracking phenomenon occurring in the connecting portion 2. FIG. FIG. 5B is a diagram showing an equivalent circuit of the load and the connection portion when a tracking phenomenon occurs, and FIG. 5C is a schematic diagram showing the relationship between the tracking resistance r and the total current Io. It is.

  First, when the motor 3 is not driven, a short-circuit current due to the tracking phenomenon does not occur in the connecting portion 2, so that the insulation abnormality determination means 5 determines that the insulation is normal, and the drive means 6 shows that in FIG. The commercial power supply voltage is supplied to the electric motor 3, and the electric motor 3 starts operation. The detection waveform of the current detection means 41 when the insulation state after the start of operation is normal becomes a waveform as shown in FIG. 3A, but the insulation resistance between the terminals of the connection portion 2 deteriorates due to the tracking phenomenon. A short-circuit current is generated between the terminals 21 and 22 (between the electric circuits) of the connection unit 2, and a current supplied to the connection unit 2 (hereinafter referred to as “total current”) is increased. As shown in (b). In this phenomenon, since the tracking resistance between the terminals is unstable, the increase in the short-circuit current of the connection portion 2 is also unstable, and as a result, the total current supplied to the connection portion 2 is also unstable. Such a phenomenon will be described in more detail with reference to FIG.

  In FIG. 5A, the case where the insulation between the terminal 21 and the terminal 22 of the connection part 2 deteriorates and the tracking phenomenon occurs will be described. The relationship between the short-circuit current Ir generated by the tracking phenomenon between the terminals and the load current Im flowing through the motor 3 can be regarded as Io = Im + Ir. Here, for convenience, assuming that the magnitude of the load impedance Z does not change, the total current Io1 supplied to the connection portion 2 when the tracking phenomenon does not occur is the tracking resistance r = ∞ (infinite). Therefore, Ir = 0 (zero), and Io1 = Im = Vs / Z. However, when tracking occurs, the insulation resistance between the terminals decreases as shown in FIG. 5B, and a tracking resistance r connected in parallel to the load is generated. When the total current supplied to the connection unit 2 at this time is Io2, Io2 = Vs / Zo. Here, Zo is a combined resistance of the load impedance Z and the tracking resistance r, and Zo = Z · r / (Z + r). Since Zo is a value smaller than Z, considering the total current Io supplied to the connection part 2 in the above case, Io1 <Io2. At this time, since the tracking resistance r changes in proportion to the degree of insulation deterioration, when applied to the above-described equation representing the total current Io flowing through the connecting portion 2, the degree of insulation deterioration (degree of tracking resistance r reduction) results. ), The total current Io also changes.

  The relationship between the tracking resistance r and the total current Io is as shown in FIG. 5C. Since the tracking resistance is unstable, one variable action that makes the peak value of the total current Io unstable. do. That is, when the peak current of the total current Io supplied to the connection unit 2 is measured, a current peak appears almost in synchronization with the maximum value of the voltage of the commercial power supply 1. When a tracking phenomenon occurs, a tracking resistance is generated in proportion to the degree of insulation deterioration, which makes the effective value and instantaneous value of the total current Io unstable. That is, the occurrence of the tracking phenomenon due to the insulation abnormality can be determined from the amount of change in the peak value of the total current, and it can be estimated from the peak value to the degree of abnormality in the insulation state.

  Based on such a concept, the output of the current detection means 41 for detecting the current flowing through the connection portion 2 is, for example, as shown in FIG. 3C by a rectifier means 42 by a diode bridge (not shown) or the like. Full-wave rectification. The A / D converter 43 samples the output of the rectifier 42 a predetermined number of times with a phase difference of a predetermined time in synchronization with the cycle of the commercial power supply 1. That is, as shown in FIG. 4A, for example, a quarter cycle of the commercial power source 1 after a predetermined timing T1 from each zero cross (zero cross 1 to zero cross 6 in FIG. 2) of the positive side and the negative side of the commercial power source voltage. The output of the rectifying means 42 shown in FIG. 3C is sampled once, for example, at the time of (T1 = 5 ms when the frequency of the commercial power supply is 50 Hz). The detection values sampled by the A / D conversion means 43 in this way are as shown in FIG.

  Next, as shown in FIG. 4C, the insulation abnormality determination unit 5 calculates the change amount (absolute value of the difference) between the current data value and the previous data value of the digital value sampled by the A / D conversion unit 43. This is repeated sequentially. At this time, the insulation abnormality determination means 5 compares the obtained change amount with a predetermined insulation abnormality determination level set in advance, and determines that an insulation abnormality has occurred when the change amount exceeds the insulation abnormality determination level. . The insulation abnormality determination level varies depending on the load (electric motor 3) and also varies depending on the operation state of the load. Therefore, it is preferable to set the insulation abnormality determination level based on an experimental value obtained by measuring an actual change amount when tracking occurs.

  FIG. 4D shows a detection example of the insulation abnormality determination means 5 determined at the insulation abnormality determination level with respect to the current change amount of FIG. 4C. The insulation abnormality determination means 5 is shown in FIG. Since the current change amounts ΔI1 to ΔI4 in c) are lower than the insulation abnormality determination level, it is determined that insulation is normal. However, since the current change amount ΔI5 is higher than the insulation abnormality determination level, it is determined that there is an insulation abnormality, and the driving means 6 The judgment result is output for.

  The drive unit 6 controls the electric motor 3 based on the output of the insulation abnormality determination unit 5. The control of the electric motor 3 is performed so that, for example, the power supply to the electric motor 3 is cut off and the operation is stopped so that safety can be ensured without causing smoke or ignition from the connecting portion 2. It is also possible to continue the operation by supplying electric power that can ensure safety without shutting off the electric power supply that stops the operation of the electric motor 3, for example, from the weak operation mode during normal use However, it is possible to perform control by a method with a smaller supply power. With such a method, it is possible to avoid a situation in which the user cannot suddenly use the device while using it.

  In addition, when a connection abnormality is detected in this way, in a configuration where control is performed using a method with a small supply power, the tracking phenomenon continues to be detected in the subsequent operation state, and further insulation abnormality is detected. In such a case, the supply power may be reduced stepwise so that the control is performed with a smaller power, and the power supply may be cut off if the insulation abnormality continues to be detected. With such a method, it is possible to avoid a situation in which the user cannot suddenly use the device while using it, and further safety can be ensured.

  As described above, in the first embodiment, the tracking phenomenon occurring in the connecting portion 2 is detected to determine the insulation abnormality between the electric paths of the connecting portion 2, and the operation of the electric motor 3 is controlled according to this determination. be able to. According to the present embodiment, detection of tracking occurrence by sampling twice in one cycle can be realized with a high detection accuracy and an inexpensive configuration, and smoke generated due to abnormal overheating when tracking occurs. -The load can be controlled to prevent ignition.

  In addition, by detecting the current flowing through the connection unit 2 and sampling the output obtained by rectifying the detected current as a digital value, a high-pass filter or the like for extracting a noise component becomes unnecessary, and external noise is measured. Therefore, it is possible to prevent an erroneous determination of the occurrence of tracking as much as possible, and the detection of the occurrence of tracking can be realized with a high detection accuracy and an inexpensive configuration. Accordingly, it is possible to provide an insulation abnormality detection device that is extremely simple, has a small number of parts, is inexpensive, has high reliability, and can prevent smoke and ignition due to insulation abnormality.

  Further, in the current sampling, since the current value at a predetermined phase angle is sampled, sampling is performed once at a predetermined timing T1 from the zero cross of the commercial power supply voltage every half cycle of the commercial power supply voltage. A / D conversion and data processing are not required, and an A / D converter with a general conversion speed or a microcomputer with a general data processing speed may be used. It is possible to provide an insulation abnormality detection device that can prevent smoke and fire.

  The insulation abnormality determination means 5 obtains the amount of change (absolute value) between the current data value and the previous data value of the digital value sampled by the A / D conversion means 43, and the obtained amount of change and the insulation abnormality judgment level. Therefore, it is determined that there is an insulation abnormality, so that an integration means for adding a small amount of detection values and accumulating them becomes unnecessary, and detection of tracking occurrence can be realized with an inexpensive configuration. Therefore, it is possible to provide an insulation abnormality detection device that can prevent smoke and ignition due to insulation abnormality with an inexpensive configuration.

  Further, the drive means 6 is configured to control so that when the insulation abnormality determination means 5 determines an insulation abnormality, the power supply to the motor 3 is cut off and the operation is stopped. It is possible to provide an insulation abnormality detection device that can stop the operation of the electric motor 3 when it occurs and can prevent smoke and ignition due to insulation abnormality.

  In the first embodiment, the case where the current is detected for each zero cross of the positive side and the negative side of the commercial power supply voltage (zero cross 1 to zero cross 6 in FIG. 2) has been described. However, the present invention is not limited to this. However, the same detection is possible even if it is performed only on either the positive electrode side (zero crosses 1, 3, 5 in FIG. 2) or the negative electrode side (zero crosses 2, 4, 6 in FIG. 2). With such a configuration, it is possible to further reduce the cost while maintaining the measurement accuracy at substantially the same level as described above, and to further reduce the influence of external noise. Furthermore, the structure which restrict | squeezes the waveform to detect, for example to 1 piece in 10 pieces and 1 piece in 20 may be sufficient. If constituted in this way, the further cost reduction can be aimed at. However, if the aperture is too narrow, it is not desirable because fluctuations in the power supply voltage affect the detection of the occurrence of tracking, and therefore it is desirable to sample at least once per second.

  Further, in the first embodiment, the predetermined timing T1 for A / D converting the output of the rectifying means 42 for measuring the current is set to a period of 1/4 cycle of the commercial power supply 1 from the zero cross of the commercial power supply voltage. For example, the case where T1 = 5 ms has been described, but the present invention is not limited to this. For example, 4 ms or 6 ms may be used, and when the current data value after current A / D conversion is compared with the previous data value, Needless to say, if the predetermined timing T1 is the same, the same detection can be performed without any problem.

  Furthermore, in the first embodiment, the output of the current detection unit 41 is sampled by the A / D conversion unit 43 without separating the frequency component and the noise component of the commercial power supply voltage. When the influence of the noise component due to noise is strong or when it is affected by external noise, an appropriate cut-off frequency is set, and an appropriate position of the circuit, for example, the front stage of the A / D conversion means 43 or the current detection means 41 It goes without saying that tracking detection can be performed more reliably by providing a low-pass filter in the subsequent stage. With this configuration, noise components can be removed more favorably, and safety and the like can be improved by performing accurate tracking detection.

  Further, in the first embodiment, the digital value is detected by the A / D conversion means 43 after the output of the current detection means 41 is rectified by the rectification means 42, but the electronic circuit is appropriately provided without providing the rectification means 42. Even if the output of the current detection means 41 is directly detected by the A / D conversion means 43 by designing the data or appropriately processing the detection value of the A / D conversion means 43, the same effect can be obtained. Needless to say.

  Furthermore, in the first embodiment, the case where the rectifying means 42 performs full-wave rectification using a diode bridge or the like has been described. However, if the sampling timing of the A / D conversion means 43 is appropriate even in a half-wave rectifier circuit, Needless to say, similar effects can be obtained. With such a configuration, it is possible to further reduce the cost while maintaining the measurement accuracy at substantially the same level as described above, and to further reduce the influence of external noise.

  Furthermore, in the first embodiment, a configuration has been described in which A / D conversion is performed only once after a predetermined timing T1, but when performing A / D conversion a plurality of times after the predetermined timing T1, a plurality of A / D conversions are performed. The average value processing may be performed on the data obtained by performing A / D conversion for the number of times, and the average value processed value may be handled as data after a predetermined timing T1. In the case of such a configuration, a higher-performance circuit element or a microcomputer is required, but the tracking detection accuracy can be further improved.

  Further, in the first embodiment, the predetermined timing T1 has been described based on the zero cross of the commercial power supply voltage as a base point. However, the same effect can be obtained even if the predetermined timing T1 is configured based on the predetermined voltage value of the commercial power supply voltage. Needless to say.

  Furthermore, in the first embodiment, in the determination of the insulation abnormality determination means 5, the amount of change between the current data value and the previous data value of the A / D conversion means 43 is compared with the insulation abnormality determination level, so that Although the case of determining an abnormality has been described, the present invention is not limited to this, and the difference between the maximum value and the minimum value within a predetermined time of the digital value sampled by the A / D conversion means 43 is obtained. A determination method may be used in which an insulation abnormality is determined when the predetermined determination level is exceeded. Similar effects can be obtained in such operations.

  Furthermore, in the first embodiment, in the determination of the insulation abnormality determination means 5, the amount of change between the current data value and the previous data value of the A / D conversion means 43 is large even once compared to the insulation abnormality determination level. However, the present invention is not limited to this. However, the present invention is not limited to this, and the case where the insulation abnormality determination level is continuously exceeded within the predetermined time or the case where the insulation abnormality determination level is exceeded is predetermined. When there are a number of times, an insulation abnormality determination may be output.

  Furthermore, in the first embodiment, the case where the insulation abnormality determination unit 5 determines the connection abnormality by comparing the amount of change with a predetermined insulation abnormality determination level is not limited to this, but the insulation abnormality determination is performed. The means 5 may set a plurality of predetermined insulation abnormality determination levels, and may determine the degree of insulation deterioration abnormality of the connection portion in multiple stages. It goes without saying that further control can be performed by carrying out in this way.

  Further, in the first embodiment, the case where the abnormality of the connection is determined using the amount of change between the current data value and the previous data value of the A / D conversion unit 43 in the determination of the insulation abnormality determination unit 5 has been described. However, the present invention is not limited to this, and the insulation abnormality determination means 5 determines that an insulation abnormality occurs when the value of the digital value sampled by the A / D conversion means 43 is larger than a predetermined insulation abnormality determination level set in advance. Also good.

Embodiment 2. FIG.
In the second embodiment, a mode including storage means for storing the determination result of the insulation abnormality determination means 5 will be described. Hereinafter, the second embodiment will be described with reference to FIG. 6 with a focus on differences from the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 6 is a block configuration diagram of an insulation abnormality detection device according to Embodiment 2 of the present invention. In FIG. 6, in the second embodiment, in addition to the configuration of the first embodiment, for example, an EEPROM-ROM capable of electrically reading / writing and erasing stored contents is used. Is stored.

  The storage means 7 is electrically written with the determination result as to whether or not the insulation state of the connection portion 2 when the motor 3 was last operated is normal immediately before the power supply of the storage means 7 is shut off. Then, when the motor 3 is operated again, the insulation abnormality determination means 5 first reads the stored contents of the storage means 7 at the previous operation, determines whether the insulation state is normal or abnormal, and the drive means 6 The judgment result is output for.

  The drive unit 6 controls the electric motor 3 based on the output of the insulation abnormality determination unit 5. That is, when the determination result at the previous operation stored in the storage unit 7 is abnormal, the drive unit 6 does not start the operation of the electric motor 3. On the other hand, when the insulation state is normal, the motor 3 is controlled by the driving means 6 to start the operation. A current flows through the motor 3 and the motor 3 rotates. Thereafter, the waveform and operation until the current of the connection unit 2 is detected and finally the insulation state is determined to be normal are the same as those in the first embodiment described above. Omit.

  As described above, in the second embodiment, in addition to the effects of the first embodiment, the output of the insulation abnormality determination means 5 is written in the storage means 7 and before the motor 3 is energized when starting the next operation. In the case where the insulation state of the connecting portion 2 is abnormal by reading the output information of the insulation abnormality determining means 5 at the previous operation of the storage means 7 and controlling the operation of the electric motor 3 based on the read contents. The re-operation of the electric motor 3 can be prevented. As a result, it is possible to provide an insulation abnormality detection device capable of preventing smoke and ignition accompanying the tracking phenomenon.

  In the second embodiment, the case where the electric power is not supplied to the motor 3 when the content of the storage means 7 is abnormal during re-operation has been described. However, the present invention is not limited to this. The electric motor 3 may be controlled to rotate at a rotational speed lower than the rotational speed. In this way, in addition to the above effects, the motor 3 can also be used as a notification means for an abnormal insulation to the user due to a decrease in the rotation speed of the motor 3, and a new notification means is provided. Without providing, it is possible to notify the user of the insulation abnormality.

  Furthermore, in the second embodiment, the determination result of the insulation abnormality determination means 5 stored in the storage means 7 is read to control the operation of the motor 3. However, the present invention is not limited to this, and the insulation abnormality determination means 5 detects the insulation abnormality. When the determination is made, for example, a current fuse or the like may be disconnected, and the commercial power supply 1 may not be energized to the electric motor 3. Thereby, the storage means 7 can be omitted.

  Furthermore, in the second embodiment, the case where an EEP-ROM is used as the storage means 7 has been described. However, the present invention is not limited to this. Needless to say, the same effect can be obtained by using a memory element that can store power by supplying power, or a latching relay that can memorize mechanically.

Embodiment 3 FIG.
In the present embodiment, the configuration and basic operation of the insulation abnormality detection device are the same as those in the first or second embodiment. In the present embodiment, different modes of the determination method for determining an insulation abnormality will be described in more detail. Hereinafter, the third embodiment will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected about the same part as each above-mentioned embodiment, and the description is abbreviate | omitted.

  7 and 9 are diagrams showing a determination method of another embodiment of the insulation abnormality determination means according to the third embodiment of the present invention, FIG. 8 is FIG. 7 and FIG. 10 is the maximum peak current value detected in FIG. FIG. 11 is a diagram for explaining a process for determining insulation abnormality by comparing a change amount ΔI which is a difference between the value and the minimum value with a predetermined insulation abnormality determination level, and FIG. FIG. 6 is a diagram for explaining a process for determining an insulation abnormality by comparing a change amount ΔI that is a difference between a minimum value and an insulation abnormality determination level set in advance. In the present embodiment, one detection section is set with a plurality of peak current values detected at a predetermined sampling timing as a set, and the difference between the largest Max value and the smallest Min value in one detection section. In this case, when the detection interval determined to be an insulation abnormality occurs continuously a plurality of times, the insulation abnormality is confirmed and the determination of the insulation abnormality is confirmed.

  7 and 9, the current values detected at a predetermined sampling timing are numbered 1 to 30 for easy explanation of the present embodiment. Samples 1 to 10 will be described as detection zone 1, 11 to 20 as detection zone 2, and 21 to 30 as detection zone 3. As shown in FIG. 7, when sampling in the detection section 1 is started, in this embodiment, the sample 1 is first stored as both the Max value and the Min value. Subsequently, when the sample 2 is detected, it is compared with the previously stored Max value and Min value, and if the value is larger than the Max value, the Max value is rewritten to the value of the sample 2 if smaller than the Min value. In the same procedure, when the sample 10 is measured in FIG. 7, the value of the sample 3 is held as the Max1 value and the value of the sample 5 is held as the Min1 value in the detection section 1. When the measurement of one detection section is completed, as shown in FIG. 8, the difference value between the Max value and the Min value in the detection section is calculated, and the difference value is compared with a preset abnormality determination threshold value. It is determined whether it is above or below the threshold. If it is equal to or greater than the threshold, a flag indicating that the threshold is equal to or greater than the threshold is set in the detection section. In FIG. 8, a circle is virtually entered in the column above the threshold value.

  Next, in the detection section 2 shown in FIG. 7, the sample 11 is first stored as both the Max value and the Min value as described above. Subsequently, when the sample 12 is detected, it is compared with the previously stored Max value and Min value. When the value is larger than the Max value, the Max value is rewritten to the value of the sample 12 when smaller than the Min value. Similarly, when the sample 20 is also measured, the value of the sample 11 is held as the Max2 value and the value of the sample 19 is held as the Min2 value in the detection section 2. When the measurement in the detection section 2 is completed, as shown in FIG. 8, the difference value between the Max value and the Min value in the detection section 2 is calculated, and the difference value is compared with a preset abnormality determination threshold value. It is then determined whether it is above or below the threshold. If it is equal to or greater than the threshold, a flag indicating that the threshold is equal to or greater than the threshold is set in the detection section.

  Thus, the threshold determination of the detection section is repeated by the same procedure, and when it is determined that the threshold is equal to or more than the threshold continuously in three detection sections as shown in FIG. 8, it is determined that an insulation abnormality is detected for the first time. That is, as a result of detecting the state as shown in FIG. 9, for example, a determination that is equal to or greater than the threshold is performed in detection sections 1 and 2 as illustrated in FIG. Therefore, in the states of FIGS. 9 and 10, it is processed that the insulation abnormality is not detected, and the normal operation state is continued.

  That is, as shown in FIG. 11, in the plurality of detection sections, the detection sections 1 to 4 are not flagged in the detection section 2 by the determination of the threshold value or more. Although the determination is detected, the insulation abnormality is not determined because there are three consecutive detection sections and the determination flag is not higher than the threshold value. In the state as shown in FIG. 11, a flag for determination above the threshold is set in the detection section 5 and the insulation abnormality is determined.

  As described above, by setting a plurality of peak current values as one set to be one detection section, it is possible to remove noise components satisfactorily and perform more accurate insulation abnormality determination. In addition, the configuration in which insulation abnormality is determined when the detection interval is continuously detected multiple times or more can be used to determine insulation abnormality with higher accuracy, and as a self-monitoring function to detect product defects. The performance can be very stable. Further, in the present embodiment, since the operation can be performed if the storage means 7 capable of storing three detection sections in succession is provided, the present embodiment is configured using an inexpensive element. In addition to being able to be implemented, it is possible to store the operation information before the occurrence of a malfunction in a longer term than in the first or second embodiment described above, and to increase the amount of information at the time of abnormal operation it can.

  In addition, the determination of how many peak current values make one detection section, the value of the abnormality determination threshold value, and how many times the detection section continuously detects the threshold abnormality is determined. There is a very close relationship with this part. That is, as to how many peak current values make one detection section as a set, for example, if it is too small, the difference between the Max-Min values becomes difficult to occur, and the insulation abnormality judgment tends to be influenced by noise components. It is in. On the other hand, if the amount is too large, the detection will be delayed although tracking continues to occur. The same can be said for the abnormality determination threshold and how many times a detection interval in which a flag equal to or greater than the threshold is set is detected as an insulation abnormality.

  Here, the value of the abnormality determination threshold value is preferably determined experimentally because it depends on the magnitude of electric power for operating the electric motor 3 and the like. For the above-described reason, the number of times of sampling within one detection section is preferably 3 to 15 times, and more preferably 5 to 10 times, when operating with a normal 50 Hz to 60 Hz power source. . Furthermore, about how many times a detection interval in which a flag equal to or greater than the threshold is set is detected as an insulation abnormality, about 2 to 4 times is desirable for the reason described above.

  Further, in the present embodiment, a configuration has been described in which an insulation abnormality is determined based on how many times a detection section in which a flag equal to or greater than the threshold is set is detected continuously. A configuration may be used in which the number of detection intervals in the set that are detected to be greater than or equal to the abnormality determination threshold is counted, and the insulation abnormality is determined when the count number is greater than or equal to a predetermined number. With such a configuration, there is a concern that the insulation abnormality detection is slightly delayed, but the noise component can be more reliably removed, and the insulation abnormality can be stably detected with high accuracy. Further, by storing the information at the time of detecting an abnormality in insulation, it is possible to store an operation state of a longer term, and to further increase the amount of information at the time of abnormal operation.

  As for the operation after the insulation abnormality is confirmed in the present embodiment, the configuration in which power is not supplied to the motor 3 or the rotation when it is determined that the insulation state is normal is the same as in the first or second embodiment. Since it is the same that the configuration in which the electric motor 3 is controlled to rotate at a rotational speed lower than the number can be taken, the description thereof is omitted. Even if the insulation abnormality determination method of this embodiment is used in Embodiment 1 or 2, it can be applied without impairing the effects described in the above-described embodiments.

Embodiment 4 FIG.
In the fourth embodiment, a mode for notifying the user of an insulation abnormality will be described. Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

FIG. 12 is a block configuration diagram of an insulation abnormality detection device according to Embodiment 4 of the present invention. In FIG. 12, in the fourth embodiment, in addition to the configuration of the first embodiment, for example, a liquid crystal display element or the like is used, and predetermined information relating to the abnormality of the insulation state is obtained based on the output of the insulation abnormality judgment means 5 by the user. Is provided with a transmission means 8 for informing the user. Further, the insulation abnormality determination means 5 of the fourth embodiment detects the insulation deterioration level from the output of the insulation abnormality detection means 4, determines the degree of abnormality of the insulation state based on this insulation deterioration level, and sends it to the transmission means 8. The judgment result is output.
Next, the operation of the fourth embodiment will be described with reference to FIG.

FIG. 13 is a diagram showing the detection timing of the insulation abnormality detection means and the operation of the insulation abnormality determination means in Embodiment 4 of the present invention. FIG. 13A is a diagram showing the amount of change, which is the absolute value of the difference between the current data and the previous data of the detected value of the A / D conversion means 43, and the judgment level of the insulation abnormality judgment means 5, and FIG. It is a figure which shows the insulation abnormality judgment result of the insulation abnormality judgment means 5. FIG.
The insulation abnormality detection unit 4 detects the current supplied to the connection unit 2 by the A / D conversion unit 43 at a predetermined sampling timing, as in the first embodiment. Then, as shown in FIG. 13A, the insulation abnormality determination means 5 obtains the amount of change (absolute value of the difference) between the current data value and the previous data value of the digital value sampled by the A / D conversion means 43. This is repeated sequentially. At this time, the insulation abnormality determination means 5 compares the obtained change amount with a predetermined determination level set in advance, and when the change amount exceeds the determination level, the insulation abnormality determination means 5 performs insulation according to the determination level. Determine the degree of abnormal condition. Since the judgment level varies depending on the load (the electric motor 3), it is preferable to set it based on an experimental value obtained by measuring an actual change amount or the like.

  As shown in FIG. 13 (b), the insulation abnormality determination means 5 has a change amount smaller than the determination level, that is, the insulation deterioration level is small, until the current change amounts ΔI1 to ΔI3 in FIG. 2 is determined to be normal. On the other hand, in the current change amounts ΔI4 to ΔI6, the current change amount is larger than the determination level, that is, the insulation deterioration level is large, and a predetermined abnormality level (for example, an abnormality 1 to 1) according to the determination levels 1 to 3 exceeding the change amount. It is determined that abnormality 3). Then, based on the output of the insulation abnormality determination means 5, for example, when the determination level is determined to be a predetermined level (for example, abnormality 3), the drive means 6 cuts off the power supply to the motor 3 and operates. Control to stop.

  When the abnormality level of the determination level (for example, abnormality 1 to abnormality 3) is determined by the insulation abnormality determination unit 5, the transmission unit 8 provides information on the determined abnormality level (for example, caution) , Warning, shutdown, etc.). In this display, information on predetermined maintenance contents (for example, a message for prompting parts replacement) may be displayed.

  As described above, in the fourth embodiment, in addition to the effect of the first embodiment, the degree of insulation abnormality of the connection portion 2 is determined based on the detected level of insulation deterioration, and the insulation state is determined according to this determination. Information about the degree of abnormality can be notified to the user.

  Further, when the operation of the electric motor 3 is interrupted, information is displayed on the transmission means 8, so that it is possible to notify the user why the operation has stopped.

  In the fourth embodiment, the case where the operation of the electric motor 3 is controlled based on the output of the insulation abnormality determining means 5 has been described. However, the present invention is not limited to this, and the operation is controlled without controlling the operation of the electric motor 3. Only the display on the means 8 may be performed.

  In the fourth embodiment, the case where a liquid crystal display element or the like is used as the transmission means 8 has been described. However, the present invention is not limited to this, and is based on a display element constituted by LEDs or the sound of a speaker or the like. But it ’s okay.

Embodiment 5 FIG.
FIG. 14 is a schematic configuration diagram of a vacuum cleaner according to Embodiment 5 of the present invention. The vacuum cleaner which is a household electrical appliance in this Embodiment 5 mounts the insulation abnormality detection apparatus of said Embodiment 1 thru | or 4.

  In FIG. 14, the electric vacuum cleaner main body 101 incorporates an electric blower 102 as a power for sucking air together with dust, and a dust collection chamber 103 is provided on the upstream side of the electric blower 102. The electric blower 102 includes an electric motor 3 and a fan that is rotationally driven by the electric motor 3. The electric motor 3 is connected to the commercial power supply 1 through the connection part 2 of the first to fourth embodiments, and the insulation state of the connection part 2 is detected by the insulation abnormality detection device (not shown). Further, the vacuum cleaner main body 101 is provided with a hose unit 105 for the purpose of extension, and one end of a hose 106 constituting the hose unit 105 is detachably connected to the vacuum cleaner main body 101. The hand handle 108 is provided at the other end. An extension pipe 109 is detachably connected to the hand handle 108, and a floor suction tool 110 is detachably connected to the upstream side of the extension pipe 109, and the electric blower 102 is collected from the floor suction tool 110. A negative pressure suction air passage is formed up to the dust chamber 103, and an exhaust air passage is formed between the downstream side of the dust collection chamber 103 and an exhaust port (not shown).

  As described above, in the fifth embodiment, the insulation abnormality detection device of the first to fourth embodiments is mounted, and the control of the electric blower 102 including the electric motor 3 and the fan and the insulation state of the connecting portion 2 are performed. By performing the detection, it is possible to prevent abnormal heating, smoke generation and ignition associated with the insulation abnormality of the connection part 2 connecting the electric motor 3 and the commercial power supply 1, and provide a highly safe vacuum cleaner related to fire. can do. In addition, by preventing smoke and ignition, smoke is not discharged into the cleaning room, so that the room is not polluted with smoke, and an unpleasant odor does not attach to the room. Therefore, the hygiene in the room is not impaired.

  In addition, in this Embodiment, although the vacuum cleaner was demonstrated as an example of household appliances, this invention is not restricted to this, If it is household appliances which have the load connected to the power supply via the connection part 2 For example, a hand dryer may be used.

It is a block block diagram of the insulation abnormality detection apparatus in Embodiment 1 of this invention. It is a wave form diagram which shows the commercial power supply waveform in Embodiment 1 of this invention. It is a wave form diagram which shows the detection waveform of the insulation abnormality detection means in Embodiment 1 of this invention. It is a figure which shows the detection timing of the insulation abnormality detection means in Embodiment 1 of this invention, and the operation | movement of an insulation abnormality judgment means. It is a figure which shows the structure of the connection part in Embodiment 1 of this invention, and the relationship between a tracking resistance and a total current. It is a block block diagram of the insulation abnormality detection apparatus in Embodiment 2 of this invention. It is a figure which shows the determination method of other embodiment of the insulation abnormality determination means in Embodiment 3 of this invention. FIG. 8 is a diagram for explaining an insulation abnormality determination process by comparing a change amount ΔI that is a difference between a maximum value and a minimum value of a peak current value detected in FIG. 7 with a preset insulation abnormality determination level. It is a figure which shows the determination method of other embodiment of the insulation abnormality determination means in Embodiment 3 of this invention. FIG. 10 is a diagram for explaining an insulation abnormality determination process by comparing a change amount ΔI which is a difference between a maximum value and a minimum value of a peak current value detected in FIG. 9 with a predetermined insulation abnormality determination level. It is a figure for demonstrating the determination process of an insulation abnormality by comparing with the insulation abnormality judgment level set beforehand about the variation | change_quantity (DELTA) I which is the difference of the maximum value of other peak electric current values. It is a block block diagram of the insulation abnormality detection apparatus in Embodiment 4 of this invention. It is a figure which shows the detection timing of the insulation abnormality detection means in Embodiment 4 of this invention, and the operation | movement of an insulation abnormality judgment means. It is a schematic block diagram of the vacuum cleaner in Embodiment 5 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Commercial power source, 2 connection part, 3 motor, 4 insulation abnormality detection means, 5 insulation abnormality judgment means, 6 drive means, 7 memory | storage means, 8 transmission means, 21 terminal, 22 terminals, 41 current detection means, 42 rectification means, 43 A / D conversion means, 101 vacuum cleaner main body, 102 electric blower, 103 dust collecting chamber, 105 hose unit, 106 hose, 107 connection part, 108 hand handle, 109 extension pipe, 110 floor suction tool, Vs commercial power supply Voltage, Z impedance, r tracking resistance, Im load current, Io total current, Ir short circuit current.

Claims (21)

Drive means for controlling the operation of a load electrically connected to the power supply via the connection;
An insulation abnormality detecting means for detecting the current flowing through the connection portion at a predetermined sampling timing;
Detecting the occurrence of a tracking phenomenon that occurs between the electrical paths of the connection portion from the output of the connection abnormality detection means, and comprising an insulation abnormality determination means that determines an abnormality in the insulation state,
The drive abnormality control device according to claim 1, wherein the drive means controls the operation of the load in accordance with an output of the insulation abnormality determination means.   2. The insulation abnormality detection device according to claim 1, wherein the drive means stops the operation of the load when the insulation abnormality judgment means judges an insulation state abnormality. Storage means for storing the determination result of the insulation abnormality determination means;
3. The drive unit according to claim 1 or 2, wherein when starting the operation of the load, the drive unit controls the operation of the load according to a determination result of the insulation abnormality determination unit stored in the storage unit. The insulation abnormality detection device described. The drive means, when the judgment result stored in the storage means is an insulation abnormality,
The insulation abnormality detection device according to claim 3, wherein the operation of the load is not started.   5. The insulation abnormality detection device according to claim 3, wherein an element that does not erase the stored contents even when power supply is cut off is used as the storage means.   6. The insulation abnormality detection device according to claim 5, wherein an EEP-ROM capable of electrical erasure and electrical writing is used as the storage means.   The insulation abnormality detection device according to any one of claims 1 to 6, further comprising a transmission means for notifying information on an insulation state abnormality judged by the insulation abnormality judgment means. Insulation abnormality detection means for detecting a current flowing in a connection portion that electrically connects a power source and a load at a predetermined sampling timing;
Insulation abnormality determining means for detecting the occurrence of a tracking phenomenon that occurs between the electrical paths of the connection portions from the output of the connection abnormality detecting means, and determining an abnormality in the insulation state;
An insulation abnormality detection apparatus comprising: a transmission means for informing information relating to an insulation state abnormality determined by the insulation abnormality determination means. The insulation abnormality determination means detects an insulation deterioration level generated between the electrical paths of the connection portion from the output of the insulation abnormality detection means, determines an abnormality degree of the insulation state based on the insulation deterioration level,
9. The insulation abnormality detection device according to claim 7, wherein the transmission means notifies predetermined information according to the degree of abnormality determined by the insulation abnormality determination means.   The connection part is at least one of a terminal block, a connector, a flat terminal, a closed-end connector, and a solder joint provided to electrically connect the power source and the load. Item 10. The insulation abnormality detection device according to any one of Items 1 to 9.   The insulation abnormality detection device according to claim 1, wherein the connection portion is a solder joint on a printed circuit board on which at least one of the driving unit and the insulation abnormality detection unit is mounted. .   The insulation abnormality detection device according to claim 1, wherein the insulation abnormality detection means detects an instantaneous value of a current supplied to the connection portion. The insulation abnormality detection means includes
Current detecting means for detecting a current flowing through the connecting portion;
Rectifying means for rectifying the output of the current detection means;
The insulation abnormality detection device according to claim 1, further comprising: an A / D conversion unit that samples an output of the rectifying unit as a digital value.   14. The A / D conversion unit samples the current flowing through the connection portion a predetermined number of times with a phase difference of a predetermined time in synchronization with a cycle of power supplied to the load. Insulation abnormality detection device.   15. The insulation abnormality detection device according to claim 14, wherein the A / D conversion unit sets the phase difference of the predetermined time to a time that is ¼ of the cycle of the power source.   The insulation abnormality detection device according to claim 14 or 15, wherein the A / D conversion means sets the predetermined number of times to once every half cycle of the power source.   The insulation abnormality determination means obtains a difference between the current data and the previous data of the digital value sampled by the A / D conversion means, and when the obtained difference value is larger than a predetermined insulation abnormality determination level set in advance, The insulation abnormality detection device according to any one of claims 13 to 16, wherein it is determined that an insulation abnormality has occurred.   The insulation abnormality determination means obtains a difference between a maximum value and a minimum value within a predetermined time of the digital value sampled by the A / D conversion means, and the obtained difference value is a predetermined insulation abnormality determination level set in advance. The insulation abnormality detection device according to claim 13, wherein when it is larger, the insulation abnormality is determined.   14. The insulation abnormality determination means determines that an insulation abnormality occurs when a value of the digital value sampled by the A / D conversion means is larger than a predetermined insulation abnormality determination level set in advance. The insulation abnormality detection device according to any one of 16.   The insulation according to any one of claims 17 to 19, wherein the insulation abnormality determination means sets a plurality of the predetermined insulation abnormality determination levels and determines the degree of insulation abnormality of the connection portion in multiple stages. Anomaly detection device. A load electrically connected to the power supply via the connection,
A home electric appliance comprising the insulation abnormality detection device according to any one of claims 1 to 20.

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