JP3466087B2 - Monitoring equipment for grounding system in electric room - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring system for a grounding system in an electric room, which constantly monitors a current abnormality in a grounding system (types A to D) in a grounding box of the electric room. It is about. 2. Description of the Related Art FIG. 9 is a connection diagram showing a grounding system in a general electric room. In FIG. 9, reference numerals 1 and 2 denote a first-class grounding system (also referred to as a Class-A grounding) and a second-class grounding system (also referred to as a Class-B grounding), and reference numerals 11 and 21 denote a first-class grounding electrode (E1). And a main ground line from the second type grounding electrode (E2). These are crimped terminals and the like on the main terminals 13 and 23 provided on the first type grounding common copper band 12 and the second type grounding common copper band 22, respectively. It is attached and fixed by. [0003] In the electric room, various devices ranging from a high-voltage lead-in cable from a power company to a low-voltage switchboard are installed. Reference numeral 3 denotes a transformer which is a main device. The primary winding 31 is connected, for example, in a delta connection to a high-voltage power supply 34, and the secondary winding 33 is connected, for example, in a star connection, and distributed to a low-voltage load group 35. Is done. [0004] According to the electrical equipment technical standards,
The transformer outer box or the iron core 32 and the like are to be subjected to a first-class grounding work, and as shown in FIG.
This is performed by connecting a branch ground wire 15 from a branch terminal 14 provided on the seed ground common copper strip 12 to an outer box or an iron core 32. [0005] The neutral point of the secondary winding 33 of the transformer, etc. is to be subjected to a second type grounding work.
This is performed by connecting a branch ground wire 25 from a branch terminal 24 provided on the seed ground common copper strip 22 to a neutral point of the secondary winding 33. From the common ground copper strips 12 and 22, separate branch ground lines 17 and 27 are connected to branch terminals 16 respectively.
And 26, and are used for grounding work of a gantry such as another transformer or switchgear. In addition, spare branch terminals 18 and 28 are often provided in advance in preparation for future expansion or repair work. [0006] In such a grounding system of an electric room, if there is no abnormality such as touching of each grounding line,
The leakage current of each part of the ground wire is at a normal level of several milliamps or less. However, in electrical rooms such as buildings and factories, as a result of repeated addition or repair of equipment compared to the time of completion during 10 to 20 years, abnormalities often occur in the grounding system. For example, in FIG. 9, the first type branch grounding lines 15 and 17 originally performed the grounding function independently of the bases of different equipments. Interference may occur via an additional connecting ground wire, pipe frame, or safety fence. In this case, a loop is formed by the following route. Branch grounding wire 15 → Point of contact between equipment stands → Branch grounding wire 17
→ Terminal 16 → Common grounded copper strip 12 → Terminal 14 → Branch ground wire 15 As a result, this loop system interlinks with a part of the spatial leakage magnetic flux formed by the current flowing through the equipment in the electric room. The loop current determined by the induced voltage and the loop impedance of the loop circulates through the path. [0010] Such a loop path is a second type of branch line 2
The same may occur between 5 and 27. In addition, there are cases where the above-described problem occurs across the first type and second type grounding systems. Branch ground wire 15 → Interference between the equipment stand and the neutral point of the transformer → Branch ground wire 27 → Terminal 26 → Second type common ground copper band 22 → Terminal 23 → Second type main ground wire 21 → Second Seed ground electrode E2 → first-class ground electrode E1 → first-class main ground wire 11 → terminal 13 → first-class ground common copper band 12 → terminal 14 → branch ground wire 15 A kind of stray circulating current caused by the contact between the ground systems or the loop configuration caused by the contact between the first type and the second type ground systems may fluctuate greatly with time and reach several amperes,
Load group 35 connected to electric indoor equipment or low-voltage switchboard
The original leakage current (1) returning to the grounding system due to the original leakage
(0 to 100 milliamps). For this reason, this is a factor that significantly impedes the introduction of various types of leakage monitoring units, and even if introduced, there are many false alarms, and in many cases, the treasure is put down. And
There is a problem that the investigation work for specifying the contact of the grounding system or the like as described above is troublesome over a long period of time using a clamp-type leakage ammeter. The present invention has been made in order to solve the above-described problems of the conventional example. An abnormal pattern of a plurality of ground wires can be immediately grasped, and the pattern can be used for expansion or repair work. Primary judgment can be made for abnormalities caused by miswiring, etc., and leakage faults caused by insulation failure due to aging, and secondary measures for subsequent improvements can be quickly and accurately taken to prevent trunk line problems. An object of the present invention is to obtain a monitoring device for a grounding system in an electric room, which can significantly improve maintenance. A monitoring system for a grounding system in an electric room according to the present invention is provided in an electric room, and is connected to a first-type and a second-type grounding pole via a main grounding line. The primary and secondary sides of each substation facility for supplying power to a load via a branch ground line are connected to each branch terminal of the first and second type grounded common copper strips of the grounded ground terminal box. In the grounding system of the electric room, a plurality of current detection sensors for detecting the current of each channel flowing through each of the main ground lines and the branch ground lines, and each of the plurality of current detection sensors based on detection values from these current detection sensors. When the current detection value for each channel exceeds the set current level and continues for the set time period, the abnormality of the ground line current of the corresponding channel is determined, and the ground line current of each channel is determined based on the abnormality determination result of the ground line current of each channel. Contact condition and leakage An abnormality monitoring monitor for patterning and determining an electric state, and display means having a plurality of abnormality display lamps for displaying a contact state and a leakage state of each ground line for each pattern . Contact condition and leakage
The plurality of abnormality display lamps based on the determination result of the power state.
Of the corresponding pattern is displayed.
It is those that. The abnormality monitoring monitor includes a plurality of display LEDs that are turned on in a test state for each channel, and a contact switch is closed when a test is set for a connection / non-connection state of each current detection sensor. , A display LED under test for displaying a test, a calibration power supply, and each of the above-described current detection sensors are provided. When the current detection sensor is not connected, the contact is closed, and when the current detection sensor is connected, A closed circuit in which a sensor presence / absence switch that can be switched to be connected to the calibration winding of each current detection sensor is connected in series, and at the time of testing, the calibration power supply is connected to each calibration winding of the connected current detection sensor. It is characterized in that a current is supplied to turn on the display LED of the corresponding channel. Further, the abnormality monitor monitors the number of times the set value of the sensitivity current for each channel, the set time period, and the detection value from the current detection sensor exceed the set value and continue the set time period in the measurement mode. A default function is provided for storing the counted cumulative frequency and the measurement state mode in a nonvolatile memory. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, Embodiment 1 of the present invention will be described. FIG. 1 is a configuration diagram illustrating a monitoring device for a grounding system in an electric room according to a first embodiment.
1, the same parts as those of the conventional example shown in FIG. 9 are denoted by the same reference numerals, and the description thereof will be omitted. As a new code, 41
Reference numerals 46 denote ZCT current sensors clamped to each ground line, and these signals are input to the abnormality monitoring monitor 60. The abnormality monitoring monitor 60 determines that the detected current of the corresponding channel is abnormal when the current detection value of each channel exceeds the set current level and continues for the set time, outputs an alarm signal 51, and outputs the ground signal. Pattern-specific abnormality display lamps 56 to 59 are provided for patterning and discriminating and displaying the line contact state and the leakage state. FIGS. 2 and 3 are views showing a front panel for performing specific operations and display of the abnormality monitoring monitor 60 and a rear panel for providing wiring. Current sensor 41
The signal outputs of Nos. To 46 are input to channels 1 to 6 via the sensor signal connection connector 52 shown in FIG. In the abnormality monitoring monitor (EL monitor) for monitoring the abnormality of the 6-channel ground line current shown in FIG.
The set value and set time limit of the sensitivity current of each channel are determined by the mode display LED 61, the mode switch 62,
The alarm display LED 63, the selection switch 64, and the display LED 65 of the display / set value of the number of times of detection are operated and displayed, and determined individually. For example, the sensitivity current is 15/50/100
/ 200/500 / 1000mA, time limit 0.5 / 1 /
Switching is possible from 3/5 seconds. When the setting of each channel is completed, by pressing the measurement switch 66, measurement is started for all the channels, and the in-measurement display LED 67 blinks. This measurement is continued until the measurement switch 66 is pressed next to stop the measurement. During this time, when a current that exceeds the set value of the sensitivity current and continues for a longer time than the set time period flows,
Channel / alarm display LED 63 corresponding to the channel
Lights up and an alarm is displayed. This alarm display is self-held even if there is no current abnormality, and the number of times is counted in the built-in memory. Then, each time a subsequent current abnormality occurs, it is accumulated by one count. FIGS. 4 and 5 are flowcharts of the waveform of the current I input to the abnormality monitoring monitor 60 and the counting means in the abnormality monitoring monitor 60 for judging the current abnormality for each channel and counting the number of times. In FIG. 4, the dashed line is the sensitivity current Is that can be set for each channel,
Points P and Q that intersect with the current waveform I indicate the start point and the end point of the current abnormality exceeding the sensitivity current Is. In the time axis, Ts represents a set time period from the start point P, and T is a time from the start point P to the end point Q. FIG. 5 shows the operation of performing the monitoring function of each channel. Is1,..., Is6 indicate the sensitivity current set for each channel CH1,. Ts1,..., Ts6 are time periods set for each channel. For example, when the measurement is started in channel 1, the input current I1 is compared with the set current level Is1 in step 71, and if I1 ≧ Is1, the time T and the set time Ts1 are set in step 72. Be compared. If T ≧ Ts1, the display LED 63 of the channel 1 is turned on in step 73, and the counter (CNT) is accumulated by one count. Even if I1 ≧ Is1, if T <Ts1, the counter does not operate and the operation starts to perform the next current monitoring. For the second and subsequent current abnormalities where I1≥Is1 and T≥Ts1, the counter advances by one count each time while the display LED remains lit in a self-holding manner. Is displayed LE
If the user notices D and presses the CALL switch 68 after the operation of ending the measurement, the count value can be displayed and recognized. In this manner, the abnormal state of the ground line current of the six channels is monitored. The accumulated count of each channel during the measurement period can be read by pressing the CALL switch 68 and selecting each channel with the selection switch 64. When reading is completed,
The count can be reset by pressing the release switch 69, and the next measurement can be started. Therefore, according to the first embodiment shown in FIG. 1, the lighting distribution of the warning display channel of the warning display LED 63 by the lighting of the warning display LED 63 by the patrol to the electric room or the abnormality display of the central monitoring room by the warning signal 51. You can know the situation. The following abnormal pattern of the grounding system can be primarily diagnosed based on the lighting pattern and the count number of the alarm channel. Pattern I: This is a case where the branch ground wires 15 and 17 are in contact with each other. Pattern II: a case where the branch ground wires 25 and 27 touch each other, the channels 5 and 6 are lit, and the others are not lit. Pattern III: branch ground lines 15 and 17 and 25 and 2
7 is a case of mutual contact, and channels 1, 2, 4,
5 or 6 is turned on, or channels 1, 3, 4, 5 or 6 are turned on. Pattern IV: This is a case where an original leakage accident has occurred, and channels 1 and 2 or 3 are turned on, or channels 4 and 5 or 6 are turned on. FIG. 6 shows a diagnosis algorithm of the abnormality monitoring monitor 60 for recognizing an abnormality pattern from the lighting distribution of each channel of the channel / alarm display LED 63 for each channel and specifically displaying the abnormality. Indicates that the channel is lit at the time of abnormality, and a minus sign indicates that the channel is not lit. In the case of the pattern I, the branch ground lines 15 and 1
The abnormality display lamp 56 in FIG. In the case of the pattern II, the fact that the branch ground wires 25 and 27 are in contact with each other is displayed by lighting the abnormality display lamp 57 in FIG. In the case of the pattern III, there are four cases as shown in the drawing, and in any case, the abnormality indication lamp 58 in FIG. 1 indicates that the ground wires 15 and 17 and 25 and 27 are in contact with each other. Is lit to display.
In the case of the pattern IV, there are four cases as shown in the figure, and in any case, the abnormality display lamp 59 in FIG. In FIGS. 1 and 6, the branch E1
Although the case where each of the ground lines of the branch E2 is two is shown, even if the number of the ground lines is three or more, the failure is classified into four patterns and displayed according to the diagnosis algorithm shown in FIG. Can be. In practice, the cases of pattern 1 to pattern 3 are often seen immediately after the construction work for extension or renovation, so that it is possible to promptly promote construction improvement activities. In addition, when no extension or renovation work is performed, the case of pattern 4 is often seen, and in this case, the grounds for shifting to the secondary diagnosis of the detailed earth leakage exploration have been obtained. As described above, according to the first embodiment, the abnormality monitoring monitor for monitoring the abnormality of the current flowing through the ground line allows the abnormality pattern of the plurality of ground lines to be immediately grasped. It is possible to temporarily judge abnormalities caused by incorrect connection due to extension or repair work, and electrical leakage abnormalities caused by insulation failure due to aging, and to quickly and accurately take secondary measures for subsequent improvement. In addition, the preventive maintenance of the trunk system can be significantly improved. Embodiment 2 FIG. In the above-described first embodiment, the case where the number of channels is 6 has been described. However, in an actual electric room, for example, when only 4 channels can be used, two channels are available, or two sets of monitors are used because nine channels are required. May be. In such a case,
The first set uses all channels, the second set uses only three channels, and leaves the remaining three channels open. In such a case, the sensor presence / absence switch 53 for each channel shown in FIG. 3 is changed from “absent” to “present” for the channel to which the ZCT current sensor is connected.
, And the channel to which the ZCT current sensor is connected is switched from “present” to “absent”. FIG. 7 shows a test circuit provided in the abnormality monitoring monitor 60 for illuminating the in-test display LED 71 shown in FIG. 2 at the time of setting a test to determine whether or not there is a measurement abnormality for each channel. In the case of the illustrated circuit example, the sensor presence / absence changeover switches 53 of the channels 1 to 3 are “Yes”.
, And the sensor presence / absence switch 53 of the channels 4 to 6 is switched to “absent”. By switching the sensor presence / absence switch 53 of each channel in this manner, channels 1-3 are connected in series with calibration windings 91-93 provided on the ZCT current sensor, and channels 4-6 are connected in series. , ZC
Since the T current sensor is not connected, the calibration winding of the sensor connected to the sensor is bypassed even if there is an unconnected vacant channel among the six channels. Will be connected in series. Accordingly, when the test switch 70 shown in FIG. 2 is pressed, the in-test display LED 71 is turned on. At this time, power is supplied to the calibration windings 91 to 93 of the connected ZCT current sensors 41 to 43 from the calibration power supply 99 to be energized, and the energization of the calibration windings shown in FIG. The display LED 63 of the channel is turned on. If the display LED 63 of the channel does not light up even though the ZCT current sensor is connected, it is a measurement abnormality of the channel,
Indicates that repair is required. When the test switch 70 is further pressed, the display LED during the test is turned off, and the test mode can be exited. By providing the test function in this way, it is possible to ensure long-term measurement reliability of the abnormality monitoring monitor 60 described in the first embodiment. Embodiment 3 The current abnormality monitor 60 shown in the first embodiment is operated by a power supply of 100 VAC. After setting the current and time limit of each channel of the abnormality monitoring monitor 60, enter the measurement mode, and during long-term unmanned continuous operation, when there is an instantaneous or 2-3 seconds or 2-3 minute power failure, It is troublesome if the set value has been reset or exited from the measurement mode. Therefore, the abnormality monitoring monitor 60 is provided with a built-in nonvolatile memory which can be reproduced after the power is turned on without erasing the contents of the memory even when the power is turned off, and each channel has a default function of the final setting. FIG. 8 is a flowchart for explaining the default function of the final setting for each channel provided in the abnormality monitoring monitor 60. That is, in the measurement end mode, the sensitivity current Is and the time period T set for each channel are set.
s are respectively stored in the memory (step 81,
82). When the measurement switch 66 shown in FIG. 2 is pressed to enter the measurement mode, this measurement mode is also stored in the memory (step 83). Further, during the measurement, the cumulative frequency counted up each time the sensitivity current and the time period satisfy the AND condition of I ≧ Is and T ≧ Ts is also stored in the memory (step 84). When a power failure occurs during the measurement, the set values Is, Ts, the cumulative frequency, and the mode of the measurement state stored in the memory are defaulted. Measurement can be continued by setting. Then, the measurement is repeated until the step 85 finally reaches the measurement end mode. As described above, by providing the default functions for the set value and the measurement start / end mode, a power failure occurs during the long-term operation of the abnormality monitoring monitor 60. Monitoring of line abnormalities can be continued. As described above, according to the present invention, a plurality of current detection sensors for detecting the current of each channel flowing through each main ground line and each branch ground line, and When the current detection value of each channel exceeds the set current level and continues for the set time based on the detection value of, the abnormality of the ground line current of the corresponding channel is determined, and the abnormality determination result of the ground line current of each of these channels An abnormality monitoring monitor for patterning and determining the contact state and the leakage state of each ground line based on the pattern, and display means having a plurality of abnormality display lamps for displaying the contact state and the leakage state of each ground line for each pattern , The abnormality monitor monitors the contact state of each ground wire and
The plurality of abnormality display labels based on the determination
Turn on the error display lamp of the corresponding pattern
Control , it is possible to immediately grasp the abnormal pattern of multiple ground wires, and from the pattern, the abnormalities caused by incorrect wiring due to expansion or repair work, and the leakage faults caused by insulation failure due to aging deterioration. Can be primarily determined, and a secondary response for subsequent improvement can be promptly and accurately performed, and a monitoring apparatus for a grounding system in an electric room, which can significantly improve preventive maintenance of a trunk system, can be obtained. Further, the abnormality monitoring monitor includes a plurality of display LEDs which are turned on in a test state for each channel, and a contact switch is closed when a test is set for a connection / non-connection state of each current detection sensor. , A display LED under test for displaying a test, a calibration power supply, and each of the above-described current detection sensors are provided. When the current detection sensor is not connected, the contact is closed, and when the current detection sensor is connected, A closed circuit in which a sensor presence / absence switch that can be switched to be connected to the calibration winding of each current detection sensor is connected in series, and at the time of testing, the calibration power supply is connected to each calibration winding of the connected current detection sensor. A current is supplied to turn on the display LED of the corresponding channel, so that a test function can be provided to ensure long-term measurement reliability. . Further, the abnormality monitor monitors the number of times that the set value of the sensitivity current for each channel, the set time period, and the detection value from the current detection sensor exceed the set value and continue the set time period in the measurement mode. Since a default function of storing the counted cumulative frequency and the measurement state mode in the non-volatile memory is provided, even if a power failure occurs during long-term operation, the monitoring of the grounding line abnormality can be continued with confidence.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall configuration diagram showing a monitoring device for a grounding system in an electric room according to the present invention. FIG. 2 is a front panel diagram showing an operation / display unit of the abnormality monitoring monitor 60 of FIG. FIG. 3 is a rear panel diagram showing wiring of the abnormality monitoring monitor 60 of FIG. 1; FIG. 4 is a waveform diagram illustrating a set current level and a set time period for determining an abnormality in the abnormality monitoring monitor 60 of FIG. 1; FIG. 5 is a flowchart for explaining the operation of a counter for cumulatively counting the number of times of abnormality determination for each channel in the abnormality monitoring monitor 60 of FIG. 1; FIG. 6 is a diagram illustrating a contact and leakage detection pattern by the abnormality monitoring monitor 60 of FIG. 1; FIG. 7 is a circuit diagram showing a test circuit provided in the abnormality monitoring monitor 60 of FIG. FIG. 8 is a flowchart illustrating a default function provided in the abnormality monitoring monitor 60 of FIG. 1; FIG. 9 is a grounding system diagram in a general electric room. DESCRIPTION OF THE SYMBOLS 1, 1st and 2nd kind grounding system, E1, 1st and 2nd kind grounding poles, 11, 21 1st and 2nd kind main grounding lines, 12, 22 1st and 2nd type common ground copper strips, 13, 14, 16, 18 Terminals provided on the 1st type common ground copper strip, 23, 24, 26, 28 Provided on the 2nd type common grounded copper strip Terminal, 3 main equipment, 31 primary winding, 34 high voltage power supply 34, 33 secondary winding, 35
Low voltage load group, 32 Transformer outer box or iron core, 15, 1
7, 25, 27 Branch ground wire, 41 to 46 ZCT current sensor, 53 Sensor presence / absence switch, 56 to 59
Error indicator lamp by pattern, 60 Error monitor monitor, 7
0 Test switch, 71 LED display during test.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02H 3 / 16,7 / 22 G01R 31/02

Claims (1)

(57) [Claim 1] A first type and a second type provided in an electric room.
Substations for supplying power to the load via the branch ground line to each of the branch terminals of the first and second type common copper strips of the ground terminal box grounded to the seed ground pole via the main ground line, respectively. In a grounding system of an electric room that connects the primary side and the secondary side of the equipment, a plurality of current detection sensors for detecting a current of each channel flowing through each of the main ground lines and the branch ground lines; When the current detection value of each channel exceeds the set current level based on the detection value from the current detection sensor and continues for the set time, abnormality of the ground line current of the corresponding channel is determined, and the ground line current of each of these channels is determined. a plurality of fault display space that displays the incompatible state and leakage status of each ground line and abnormality monitoring monitor to determine by patterning, and crossed state and leakage status of each ground line by pattern based on the abnormality determination result And display means having said abnormality monitoring monitor, incompatible state and leakage like the ground line
The plurality of abnormality indicator lamps are
A monitoring device for a grounding system in an electric room, which controls lighting of an abnormality display lamp of a corresponding pattern .