JP6382576B2 - Insulation degradation position specifying device and voltage measuring device - Google Patents

Description

  Embodiments described herein relate generally to an insulation deterioration position specifying device that specifies an insulation deterioration position or an accident point, and a voltage measurement device applied thereto.

  In general, a plurality of lights for aircraft guidance are installed at airports around a runway. Normally, each lamp receives power via underground cables buried in the ground.

  This underground cable is protected around the conductor by an insulating coating, thereby realizing ground insulation. However, the insulation coating causes insulation deterioration due to aging and environmental deterioration, and when this insulation deterioration becomes large, a ground fault occurs.

  For this reason, a technique for identifying an insulation deterioration position or an accident point is important.

  As a technique for identifying an insulation deterioration position or an accident point, for example, there is an accident point identification technique for identifying an accident point using the length of an underground cable. Specifically, the following equation (1) is used. To identify the accident point. When specifying the accident point, for example, power is applied to both ends of the underground cable. V1 and V2 indicate the values of the ground voltage measured at the connection point, and V1 ′ and V2 ′ indicate the values of the ground voltage measured at the connection point when the polarity of the power supply applied to the connection point is reversed. Indicates the value. L represents the length of the underground cable, and x represents the distance from the connection point to the accident point.

x / L = {2 (V1−V2 ′) / V1−V1 ′ + V2′−V2} × 100 (1)
The accident point identification technique for identifying the accident point using the above-described equation (1) is advantageous in that it is resistant to noise because it simultaneously measures two ground voltages and cancels noise transmitted to the two ground voltages. It has.

JP 2012-122752 A

  In the conventional fault point identification technology, measuring instruments are usually provided in the first ground voltage measuring unit for measuring V1 and V1 ′ and the second ground voltage measuring unit for measuring V2 and V2 ′, respectively. doing. The first ground voltage measuring unit and the second ground voltage measuring unit are mainly composed of resistors and operational amplifiers, and the resistance value and output voltage of the component change with temperature change. Moreover, in order to compensate for the tolerance of the resistance, the measurement characteristic between the input and output is adjusted manually, but it is impossible to eliminate the error between the input and output. As a result, an error occurs between the output of the first ground voltage measuring unit and the output of the second ground voltage measuring unit, and the accident point cannot be specified accurately.

  Moreover, in the conventional fault point identification technique, for example, when the applied DC voltage becomes abnormal or when the above-described component failure (open mode) occurs, the measurement result becomes unstable and the fault point is accurately identified. I can't.

  In other words, the conventional accident point identification technique has a problem that the accident point cannot be accurately identified.

  As a result, after identifying the accident point, this accident point identification work goes to the site to confirm the accident point, but because the accident point identification accuracy is low, it covers a wide range including the identified accident point position. The accident point must be confirmed.

  In addition, since these operations are performed with the lamp power supply stopped, it is necessary to quickly recover the operation. However, it is difficult to shorten the operation time, and the burden on the worker is great.

  Therefore, the problem to be solved by the present invention is to provide an insulation deterioration position specifying device capable of specifying an insulation deterioration position or an accident point with high accuracy and a voltage measuring device applied thereto.

According to the embodiment, the cable is arranged so as to form a loop on the output side of the AC power source, and the insulation in the airport lighting power system in which a lighting circuit unit including a plurality of lighting-related load devices is connected in series to the cable. A voltage measuring device applied to an insulation deterioration position specifying device that specifies a deterioration position or an accident point, and is connected to both ends of the cable instead of the AC power source, and applies a DC voltage to the lighting circuit portion. A power source, a polarity switching unit provided on the output end side of the DC power source and inverting the polarity of the DC voltage applied from the DC power source to the lighting circuit unit; and the polarity of the DC voltage is inverted through the polarity switching unit. In each of the front and rear, the ground voltage appearing at both ends of the cable is measured through a common circuit one by one and obtained by the measurement. The ground voltage measurement value of the number, comprising a voltage measuring means for sending as information to use for a particular insulation deterioration position or the fault point, the voltage measuring unit, a mode for measuring the voltage to ground appearing at one end of the cable There is provided a voltage measuring device comprising a measurement switching means for switching to a mode for measuring a ground voltage appearing at the other end .

  According to the embodiment, the insulation deterioration position or the accident point can be specified with high accuracy.

The lineblock diagram showing the insulation degradation position specific device of the airport lighting power system concerning a 1st embodiment. The block diagram of a general airport light power supply system. The figure which shows the apparatus (DC power supply, voltage measurement part) connected to the both ends of an underground cable when pinpointing a ground fault accident position. The functional block diagram which comprises the ground fault accident position determination part shown in FIG. The equivalent circuit diagram when the rubber transformer connected to the underground cable is replaced with a resistor. The figure which shows the process sequence of the fault point specific method of the ground fault accident position determination part and airport lighting power supply system in 1st Embodiment. FIG. 5 is a data array diagram of a device management table created by the device required information calculation unit shown in FIG. 4. The figure which gave the marking which shows an accident point to the load equipment position used as an accident point. The figure which shows the shift | offset | difference range of the estimated position which changes according to an apparatus attachment position and ground fault resistance. The graph which shows a mode that the error ((ohm)) of the distance (resistance value) to the presumed apparatus position with respect to the measurement output error (%) of a measurement circuit differs in a prior art and 1st Embodiment. The block diagram which shows a part of structure which concerns on 2nd Embodiment. The flowchart which shows the operation | movement which concerns on the same embodiment.

  Hereinafter, embodiments will be described with reference to the drawings.

(First embodiment)
First, the first embodiment will be described.

FIG. 1 is a configuration diagram illustrating an insulation deterioration position specifying device of an airport lighting power system according to a first embodiment.
The airport lighting power supply system includes a constant current power source 1 that supplies power at a constant current waveform to connection points 2 and 3 at all times, and an underground cable 4 that is connected to the connection points 2 and 3 in a loop. And the lighting circuit section 5 connected in series to the underground cable 4 and when specifying the insulation deterioration position or the fault point, the constant current power source 1 is disconnected and the connection points 2 and 3 are deteriorated in insulation. The position specifying device 10 is connected.

  The constant current power source 1 generates an AC power source waveform having a required constant current from a commercial AC power source and supplies the waveform to the lighting circuit unit 5 through the connection points 2 and 3 and the underground cable 4.

  As shown in FIG. 2, the lamp circuit section 5 is connected to the underground cable 4 in series with rubber transformers 6 corresponding to the number of group lamps, and the lamp 7 is connected to the secondary winding side of each rubber transformer 6. Is done. That is, the lighting circuit unit 5 is connected to the underground cable 4 in series with a number of rubber transformers 6... And connected to the constant current power source 1 so as to form a loop.

  Here, the lights 7 include many other types of lights such as runway lights, taxiway lights, taxiway centerline lights, etc. installed on airport runways and taxiways.

  The insulation deterioration position specifying device 10 includes a voltage measuring device 101 and an information processing device 102. The voltage measuring device 101 is configured by hardware such as an electric circuit, for example, and includes a DC power supply 11, a polarity switching unit 12, and a voltage measuring unit 13. The information processing apparatus 102 is realized by, for example, a computer having a processor that executes various processes by software, and includes a ground fault position determination unit 14, an information storage / storage unit 15, and an external output device 16.

  The DC power source 11 applies a DC voltage to the lighting circuit unit 5 connected to the underground cable 4 that is a target of occurrence of a ground fault or the like.

  The polarity switching unit 12 is provided on the output end side of the DC power supply 11 and has a function of inverting the polarity of the DC voltage applied from the DC power supply 11 to the lighting circuit unit 5 when the ground fault position is specified.

  The voltage measuring unit 13 detects the terminal voltage of the lighting circuit unit 5 that is a target of occurrence of a ground fault, and the like before and after inverting the polarity of the DC voltage through the polarity switching unit 12. The ground voltage appearing at both ends (connection points 2 and 3) of the cable 4 is measured one by one through a common circuit, and a plurality of ground voltage measurement values obtained by the measurement are measured as the fault point of the ground fault or insulation. It has a function of sending it to the information processing apparatus 102 as information used for specifying the degradation position. The voltage measurement unit 13 includes a measurement switching unit 13-1, a filter unit 13-2, and a ground voltage measurement unit 13-3 as main components. The filter unit 13-2 includes an insulation circuit 131 having an insulation resistance, a filter circuit 13-2 for removing noise components, and an analog / digital conversion circuit 133 for converting a ground voltage measurement value from an analog signal to digital data. Yes. The ground voltage measuring unit 13-3 is configured to calculate the ground voltage at the connection point 2 or the connection point 3 based on the digital data output from the analog / digital conversion circuit 133, and to switch to the polarity switching unit 12. An output circuit 135 that outputs an instruction and a switching instruction to the measurement switching unit 13-1 and outputs a calculation result of the calculation circuit 134 is provided.

  The measurement switching unit 13-1 has a function of switching between a mode for measuring the ground voltage V1 appearing at the connection point 2 and a mode for measuring the ground voltage V2 appearing at the connection point 3. The filter unit 13-2 suppresses an induced noise component included in the ground voltage appearing at each of the connection points 2 and 3, and the ground voltage from which the noise component has been removed is applied to the common ground voltage measuring unit 13-3. Is done. The ground voltage measuring unit 13-3 measures the ground voltage appearing at the connection point 2 and the connection point 3 while switching the measurement voltage by the measurement switching unit 13-1, and sends each measurement value to the ground fault position determination unit 14. Specifically, the ground voltage measuring unit 13-3 causes the ground voltage V1 appearing at the connection point 2 and the ground voltage measuring unit 13-3 similarly to the ground voltage V2 appearing at the connection point 3 by the measurement switching unit 13-1. Measurements are sequentially made while switching, and the measured values are sent to the ground fault position determination unit 14.

  The ground fault position determination unit 14 includes ground voltage measurement values received from each ground voltage measurement unit 13-3 and information related to the lighting circuit unit 5 including the underground cable 4 stored in the information storage storage unit 15. That is, by using attributes such as the number of rubber transformers 6,..., Resistance values, and information indicating the circuit configuration, for example, a device that is a ground fault point indicated by a cross in FIG. )).

  As shown in FIG. 4, the ground fault position determination unit 14 includes device required information calculating means 14 </ b> A for calculating device necessary information, for example, DC resistance and distance (device position) to each device (for example, rubber transformer), Using data such as ground voltages V1 ′ and V2 ′ measured by the ground voltage measurement unit 13-3 after the polarity of the ground voltages V1 and V2 measured by the voltage measurement unit 13-3 and the DC power supply 11 is inverted. , Ground fault attribute value estimation means 14B for estimating attribute values such as the number of equipment from the connection point 2 to the ground fault point and the added resistance, and the attribute values estimated by the ground fault attribute value estimation means 14B and the calculation of necessary equipment information And ground fault equipment position specifying means 14C for specifying the equipment position close to the ground fault point from the distance (equipment position) to each equipment (for example, rubber transformer) obtained by means 14A.

  As shown on the right side of FIG. 6 to be described later, the information storage unit 15 includes a cable information storage unit 15a, a rubber transformer information storage unit 15b, and a circuit configuration information storage unit 15c.

  The cable information storage unit 15a stores at least data indicating the line type and data indicating the resistance per m or km of the line type. The rubber transformer information storage unit 15b stores at least data indicating the transformer type and resistance. Not only one type but also a plurality of line types and transformer types, data indicating resistance per km and data indicating resistance of the rubber transformer are stored in the same manner.

  The circuit configuration information storage unit 15c includes data indicating circuit components for constructing the lighting circuit unit 5 including the underground cable 4 connected to the constant current power source 1, data indicating a frame image, and digital data in a bitmap format. In addition to the converted and filed image file, data such as DC resistance and distance (device position) to each device (for example, each rubber transformer) is stored.

  The external output device 16 outputs a specific position of the ground fault point to the outside, and includes a data processing unit 16-1 and a display device 16-2.

  The data processing unit 16-1 reads information related to the lighting circuit unit 5 including the underground cable 4 stored in the circuit configuration information storage unit 15c, and includes a lighting circuit including the cable 4 that is a target of occurrence of a ground fault or the like. The circuit configuration image data corresponding to the unit 5 is generated, and the required graphic marking that is easy for the user to grasp is provided at the device specific position (location) specified by the ground fault position determination unit 14 in the image data. And process to indicate the location where the ground fault occurred.

  The display device 16-2 displays the circuit configuration image data of the lighting circuit unit 5 subjected to the marking processed by the data processing unit 16-1.

  Next, the operation of the insulation deterioration position specifying device and the accident point specifying method of the airport lighting power system configured as described above will be described with reference to the drawings.

  In the airport lighting power supply system shown in FIG. 3, when the occurrence of a ground fault is confirmed from the lighting circuit unit 5 by an insulation resistance meter built in the constant current power supply 1, the constant current power supply 1 is disconnected from the connection points 2 and 3.

  When the constant current power supply 1 is disconnected, the lamp power supply systems belonging to many other groups installed are in a live line state, and the dimming operation of the lights by the controller controls the other many group cables 4. Under the influence of induction noise, it becomes an error factor.

  Therefore, instead of the constant current power source 1, the polarity switching unit 12 and the voltage measuring unit 13 constituting a part of the insulation degradation position specifying device 10 shown in FIG. Is applied to the lighting circuit unit 5 through the polarity switching unit 12, and the voltage measurement unit 13 measures the ground voltages V1 and V2 appearing at both ends of the underground cable 4 connected to the lighting circuit unit 5. .

  Here, in the voltage measuring unit 13, not only the ground voltage V1 and V2, but also a large amount of distortion components superimposed on the constant current waveform by the dimming operation by the controller or other underground in the live line state attached together. It is measured in a state that includes the noise component induced from the cable.

  Therefore, the voltage measuring unit 13 is provided with a filter unit 13-2. This filter unit 13-2 has a relatively small change among a large amount of distortion component (a kind of induction noise) superimposed on a constant current waveform and an induction noise component entering from another underground cable in a live state. The induced noise component is removed, and the signal after the removal of the induced noise component is sent to the ground voltage measuring unit 13-3.

  As a result, each ground voltage measuring unit 13-3 measures the ground voltages V1, V2 appearing at both ends of the cable 4 after removing the induced noise component having a relatively small change. The measured result is temporarily stored in the ground fault position determination unit 14 or an appropriate buffer memory (not shown).

  Of the distortion component superimposed on the constant current waveform and the induction noise component entering from other underground cables in the live state, the noise component having a relatively large level change is expressed by the following equations (3) and ( By taking the difference in ground voltage according to 4), for example, V1-V2, the corresponding induced noise components cancel each other, and the generation of error factors can be suppressed.

  Subsequently, the polarity switching unit 12 is switched by a switching instruction from the voltage measuring unit 13 or artificially, a predetermined DC voltage whose polarity is reversed from the DC power supply 11 is applied to the lighting circuit unit 5, and the voltage measuring unit 13 The ground voltages V1 ′ and V2 ′ after induction noise removal appearing at both terminals of the circuit unit 5 are measured and stored in the ground fault position determination unit 14 or an appropriate buffer memory (not shown).

  Next, the identification of the ground fault point by the ground fault position determination unit 14 will be described with reference to FIGS. FIG. 5 is a diagram showing an equivalent circuit in which the rubber transformer 6 constituting the lighting circuit section 5 in the event of a ground fault is replaced with a resistor, where Rtr is the resistance value of one rubber transformer 6 and 8 is the ground value. A fault point, 9 indicates ground fault resistance.

  Prior to identifying the position of the ground fault accident, the ground fault position determination unit 14 executes the device necessary information calculation unit 14A. The equipment required information calculation unit 14A uses the information stored in the cable information storage unit 15a, the rubber transformer information storage unit 15b, and the circuit configuration information storage unit 15c constituting the information storage unit 15 to start the lighting circuit from the connection point 2. The DC resistance and distance (device position) to each device (for example, each rubber transformer 6,...) Constituting the unit 5 are calculated (step S1).

  Specifically, the device necessary information calculation unit 14A is connected to the device (rubber transformer 6) having the device number “1” at the arrangement position closest to the connection point 2, for example, from the circuit configuration information of the circuit configuration information storage unit 15c. From the length of the cable 4 connected from the connection point 2 to the device of the device number “1”, the device number “1” from the resistance of the line type of the cable 4 to be added and the resistance of the device in question (DC resistance) For example, a device management table 15c1 as shown in FIG. 7 is created on the circuit configuration information storage unit 15c.

  That is, the device necessary information calculation unit 14A calculates the addition resistance from the connection point 2 to each device and the distance (device position) to each device, and the device number and device of each device obtained from the circuit configuration information storage unit 15c. Write in the device management table 15c1 in a state associated with the name.

  Subsequently, the ground fault position determination unit 14 executes the ground fault attribute value estimation unit 14B. Whether the ground fault attribute value estimation means 14B receives the ground voltages V1 and V2 measured by the ground voltage measuring units 13-3 of the voltage measuring unit 13 and the ground voltages V1 ′ and V2 ′ obtained after the polarity is inverted. Or, by acquiring the ground voltages V1 and V2 and the ground voltages V1 ′ and V2 ′ stored in appropriate storage means based on the measurement completion signal (step S2), a ground fault occurs from the connection point 2. The number of devices up to point 8 is estimated (step S3).

  Specifically, the resistance of the underground cable 4 from the connection point 2 to the connection point 3 and the total resistance of the rubber transformer 6,..., Rall, the total circuit resistance from the connection point 2 to the ground fault point 8 When the resistance obtained by adding all of the resistance of the underground cable 4 and the resistance of the rubber transformer 6 is Rx, the voltage between the ground voltage V1 at the connection point 2 and the ground voltage V2 at the connection point 3 is Such a relational expression is established.

V1 = (Rx / Rall). (V1-V2) (2)
V2 =-{(Rall-Rx) / Rall}. (V1-V2) (3)
Further, the following relational expression is established between the ground voltages V1 ′ and V2 ′ measured after the polarity of the DC power supply 11 is reversed.
V1 ′ = (Rx / Rall) · (V1′−V2 ′) (4)
V2 ′ = − (Rx / Rall) · (V1′−V2 ′) (5)
Therefore, the following relational expression (6) is derived from the expressions (2) and (4).
Rx (V1-V2) -V1.Rall = Rx (V1'-V2 ')-V1'.Rall
(6)
If this relational expression (6) is arranged for Rx, the following arithmetic expression can be derived between the resistance Rx from the connection point 2 to the ground fault point 8 and the total circuit resistance Rall.
Rx = {(V1−V1 ′) / (V1−V1′−V2 + V2 ′)} · Rall (7)
Here, in general, since the resistance of the rubber transformer 6 is the resistance of the underground cable 4, the resistance of the airport lighting power system is approximately equal to the total resistance of the rubber transformer 6. When the total number of rubber transformers 6 is Ntr and the number (attribute value) of the rubber transformers 6 from the connection point 2 to the ground fault point 8 is Nfl, the following equation is obtained.

Rall≈Rtr × Ntr (8)
Rx≈Rtr × Nfl (9)
Nfl = {(V1−V1 ′) / (V1−V1′−V2 + V2 ′)} · Ntr (10)
That is, the connection between the ground voltages V1, V2, V1 ′, V2 ′ measured by each ground voltage measuring unit 13-3 and the total number Ntr of the rubber transformers 6 constituting the lighting circuit unit 5 according to the equation (10). The number of rubber transformers 6 (ground fault attribute value) from point 2 to ground fault point 8 can be obtained (step S3).

  When estimating the ground fault attribute value by the ground fault attribute value estimating means 14B, for example, in the circuit configuration of FIG. 5, the cable 4 from the connection point 2 to the first rubber transformer 6 (1) is long, and the rubber transformer 6 Resistance >> The resistance relationship of the underground cable 4 may not hold.

  At this time, Rall is a circuit resistance obtained by adding all the resistances of the cable 4 from the connection point 2 to the connection point 3 and the resistances of the rubber transformers 6,..., And the cable from the connection point 2 to the first rubber transformer 6 (1). When the resistance is Rpri and the resistance of each rubber transformer 6 is Rtr, the above equation (10) can be expressed as the following equation (11).

Nfl = [{(V1−V1 ′) / (V1−V1′−V2 + V2 ′)} · Rall
−Rpri] ÷ Rtr (11)
Therefore, even when the cable 4 from the connection point 2 to the first rubber transformer 6 (1) is long, the number of the rubber transformers 6 from the connection point 2 to the ground fault point 8 is calculated using the equation (11). It can be obtained (step S3).

  Next, after calculating the number Nfl of the rubber transformers 6 up to the ground fault point 8, the ground fault position determination unit 14 executes the ground fault device position specifying means 14C.

  The ground fault equipment position specifying means 14C compares the number Nfl of rubber transformers 6 from the connection point 2 to the ground fault point 8 with the equipment number (rubber transformer number) stored in the equipment management table 15c1 (step S4). .

  Then, the Nfl-th device number from the connection point 2 corresponding to the number Nfl of rubber transformers 6 is specified from the device management table 15c1, and the device name and device position (distance to the device) corresponding to the device number are specified. (Step S5), the data is sent to the data processing unit 16-1.

  Here, the data processing unit 16-1 includes, for example, frame image data of the lighting circuit unit 5 to be generated such as a ground fault from the circuit configuration information storage unit 15c, or image file data converted into digital data by a bitmap method, Alternatively, circuit component data for constructing the lighting circuit unit 5 is taken out. In particular, in the case of circuit component data, circuit configuration image data of the lighting circuit unit 5 is created according to a predetermined editing procedure software.

  When the data processing unit 16-1 receives the device name and the device position (distance to the device) from the ground fault position determination unit 14 after creating the circuit configuration image data (including the image file and the image file), Of the device images that are consecutive on the component image data, a required image that makes it easy for the user to grasp the ground fault point, such as an X mark, is displayed on the device image portion corresponding to the device name and the corresponding device position (distance to the device). The marking data 21 is given and displayed on the display device 16-2.

  FIG. 8 shows a screen display example displayed on the display device 16-2. That is, on the display screen, images of the rubber transformers 6 ′,. It shows that a ground fault point exists at the position of the transformer 6 '. Reference numeral 22 represents a range of misalignment of the device determined from the device position and ground fault resistance.

  Usually, the device position slightly deviates depending on the magnitude of the ground fault resistance 9 at the ground fault point 8 (see FIG. 9). Therefore, for example, marking data 21 with a mark X is given to the corresponding estimated device position (distance to the device). For example, by clearly indicating 22 with a solid line frame, the confirmation range of the ground fault point is clarified, and as a result, it is possible to quickly determine whether or not to replace the device including the cable and the rubber transformer.

  Excluding the ground fault resistor 9 having an extremely large size, if the corresponding device position (distance to the device) is a position from, for example, “49” to “149” across the central device number, for example, “99”, The device position can be specified with a very small deviation range.

  Therefore, according to the present embodiment, the voltage measuring unit 13 is connected to both ends (connection points 2 and 3) of the underground cable 4 before and after the polarity of the DC voltage is inverted through the polarity switching unit 12, respectively. The ground voltage that appears is measured one by one through a common circuit, and a plurality of ground voltage measurement values obtained by the measurement are used as information used to identify the ground fault accident position or insulation degradation position that is the accident point. Since it has a function to send to the ground, it is possible to share a single measurement circuit that has been provided separately for measuring the ground voltage at connection points 2 and 3, and cancel measurement errors. And a highly accurate measurement result can be obtained.

  FIG. 10 shows how the error (Ω) of the distance (resistance value) to the estimated device position with respect to the measurement output error (%) of the measurement circuit differs between the conventional technique and the first embodiment.

  In the prior art, the ground voltages V1 and V1 ′ and the ground voltages V2 and V2 ′ are measured using separate ground voltage measurement units (measurement circuits), and thus errors occur in the measurement values between the measurement circuits. For example, when the errors between the measurement circuits are different in the plus direction and the minus direction as shown in FIG. 10, even if the error is 1%, the error in the estimated distance to the device (resistance value) is 0. It will shift by 1Ω. This value is equivalent to 51 m (from 1.953 Ω / 1 km) in the case of a cable for one 100 W type rubber transformer from the actual measurement value. Here, in order to reduce the measurement error, an expensive component having a small component tolerance is required, and further, the time required for the adjustment is large, resulting in an increase in cost.

  On the other hand, in the present embodiment, since one ground voltage measurement unit (measurement circuit) is commonly used for the measurement of the ground voltages V1 and V1 ′ and the measurement of the ground voltages V2 and V2 ′, an error between the measurement circuits. Is canceled, and as shown in FIG. 10, the estimated distance to the device (resistance value) has no error at all. Furthermore, since expensive parts are not required and adjustment is not required, the cost can be reduced.

  In the above embodiment, for the sake of convenience, a ground fault has been described as an example of an accident in the lighting circuit unit 5 including the cable 4, but at the time of periodic inspection by an operator, for example, before a ground fault occurs. At the time of an accident sign that a certain insulation resistance is greatly reduced, if the addition resistance from the connection point 2 to the part where the insulation resistance is greatly reduced is Rx, the dielectric strength of the lighting circuit section 5 including the cable 4 is reduced. The corresponding site can be easily identified.

(Second Embodiment)
Next, a second embodiment will be described.
Here, description of portions common to the first embodiment is omitted. Below, it demonstrates centering on a different part from the above-mentioned 1st Embodiment.

  In the first embodiment described above, since one ground voltage measurement unit (measurement circuit) is shared by the measurement of the ground voltages V1, V1 ′ and the measurement of the ground voltages V2, V2 ′, Although the error can be canceled and the error can be suppressed to the estimated distance (resistance value) to the device, for example, when a component such as a resistor is in the open mode, the output of the voltage measuring unit 13 is not stabilized. It becomes difficult to identify the accident point. Therefore, in the second embodiment, a function for determining whether or not the DC power supply 11 and the voltage measurement unit 13 are normal is further provided.

  FIG. 11 is a block diagram showing a functional configuration according to the second embodiment further provided in the insulation deterioration position specifying device 10 shown in FIG. 1.

  A circuit abnormality detection circuit 136 and a circuit abnormality notification unit 137 as shown in FIG. 11 are provided in, for example, the voltage measuring device 100 or the information processing device 102 of the insulation degradation position specifying device 10 shown in FIG.

  The circuit abnormality detection circuit 136 causes the circuit abnormality notification unit 137 to output a signal indicating abnormality when the value measured by taking the output of the DC power supply 11 into the voltage measurement unit 13 deviates from a predetermined range. In this case, the output of the DC power source 11 is taken into the voltage measuring unit 13 without passing through the connection points 2 and 3, for example, and passed through the measurement switching unit 13-1, the filter unit 13-2, and the ground voltage measuring unit 13-3. The measurement is performed and whether or not there is an abnormality is determined.

  The circuit abnormality notification unit 137 notifies the circuit abnormality by voice or display according to the signal output from the circuit abnormality detection circuit 136.

  The operation of the insulation deterioration position specifying device 10 having such a function will be described with reference to the flowchart of FIG.

  The insulation degradation position specifying device 10 first takes the output of the DC power supply 11 into the voltage measuring unit 13 and measures it (step S11), and confirms whether or not the measurement result is within a predetermined range, thereby causing an abnormality in the circuit. It is determined whether or not there is (step S12). In this case, the determination criterion is that the total of the power supply fluctuation, load fluctuation, and temperature fluctuation of the DC power supply 11 is, for example, ± 2.5% of the output voltage. It is determined that the range of ± 5% which is twice the normal value is normal.

  If the measurement result is within the predetermined range (YES in step S13), it is considered that there is no abnormality (normal) (step S14), and the processing in steps S1 to S5 in FIG. 6 is performed as in the case of the first embodiment described above. Implement (step S15).

  On the other hand, if the measurement result is not within the predetermined range (NO in step S13), it is considered that there is an abnormality (step S16), and a circuit abnormality (or apparatus abnormality) is notified by voice or display to prompt the worker to stop the work. (Step S17).

  According to the present embodiment, by monitoring the DC power supply 11 and the voltage measuring unit 13 in advance, it is possible to prevent a phenomenon in which an accident point cannot be specified due to a defect in a circuit or the like.

  In the above embodiment, for the sake of convenience, a ground fault has been described as an example of an accident in the lighting circuit unit 5 including the cable 4, but at the time of periodic inspection by an operator, for example, before a ground fault occurs. At the time of an accident sign that a certain insulation resistance is greatly reduced, if the addition resistance from the connection point 2 to the part where the insulation resistance is greatly reduced is Rx, the dielectric strength of the lighting circuit section 5 including the cable 4 is reduced. The corresponding site can be easily identified.

  As described above in detail, according to each embodiment, it is possible to accurately specify an insulation deterioration position or an accident point.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Constant current power source, 2, 3 ... Connection point, 4 ... Underground cable, 5 ... Light circuit part, 6, 6 (1) ... Rubber transformer, 7 ... Light, 8 ... Ground fault point, 9 ... Ground Junction resistance, 10 ... insulation degradation position specifying device, 11 ... DC power supply, 12 ... polarity switching unit, 13 ... voltage measurement unit, 13-1 ... measurement switching unit, 13-2 ... filter unit, 13-3 ... ground voltage measurement , 14 ... Ground fault position determination unit, 14A ... Equipment required information calculation means, 14B ... Ground fault attribute value estimation means, 14C ... Ground fault equipment position specifying means, 15 ... Information storage storage section, 15a ... Cable information, 15b ... rubber transformer information, 15c ... circuit configuration information, 16 ... external output device, 16-1 ... data processing unit, 16-2 ... display device, 21 ... marking data, 22 ... device misalignment range, 101 ... voltage measuring device , 102 ... Information processing device, 131 ... Insulation circuit 132 ... filter circuit, 133 ... analog / digital conversion circuit, 134 ... arithmetic circuit, 135 ... output circuit, 136 ... circuit fault detecting circuit, 137 ... circuit abnormality notification unit.

Claims (5)

A cable is arranged in a loop on the output side of the AC power supply, and the insulation deterioration position or accident point in the airport light power supply system in which a light circuit part equipped with a plurality of lighting load devices is connected in series to the cable is indicated. A voltage measuring device applied to an insulation deterioration position specifying device to be specified,
A DC power source connected to both ends of the cable instead of the AC power source and applying a DC voltage to the lighting circuit unit,
Polarity switching means provided on the output end side of the DC power supply, for reversing the polarity of the DC voltage applied from the DC power supply to the lighting circuit unit,
Before and after reversing the polarity of the DC voltage through the polarity switching means, the ground voltage appearing at both ends of the cable is measured one by one through a common circuit, and a plurality of ground voltage measurements obtained by the measurement are measured. Voltage measuring means for sending the value as information used to identify the insulation degradation position or the fault point , and
The voltage measuring means includes
A voltage measuring apparatus comprising: a measurement switching means for switching between a mode for measuring a ground voltage appearing at one end of the cable and a mode for measuring a ground voltage appearing at the other end . A voltage measuring device according to claim 1 ;
Using a plurality of ground voltage measurement values measured by the voltage measuring device and information indicating the attribute and circuit configuration of the lighting circuit unit including the cable stored in a predetermined storage unit, the load device at the accident point An insulation deterioration position specifying device comprising: an information processing device including an accident position determining means for specifying The information processing apparatus includes:
The apparatus further comprises output means for displaying on the display device what the load device at the accident point specified by the accident position determination means is displayed on the image showing the circuit configuration of the lighting circuit section including the cable. The insulation deterioration position specifying device according to claim 2 . 2. The abnormality detection unit according to claim 1 , further comprising an abnormality detection unit that outputs a signal indicating an abnormality when a value measured by taking the output of the DC power supply into the voltage measurement unit deviates from a predetermined range. Voltage measuring device. The voltage measuring device according to claim 4 , further comprising an abnormality notifying unit that notifies an abnormality by sound or display in accordance with a signal output from the abnormality detecting unit.

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