JP2006136158A - Apparatus coping with ground fault - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus coping with ground fault which can automatically specify a concrete ground fault position and separate the ground fault position, while maintaining the operation of a stable load. <P>SOLUTION: The apparatus coping with ground fault includes switches 5a and 5b, arranged on a plurality of power lines 4a and 4b for connecting a plurality of loads 12a and 12b to a common bus-bar 3, a ground fault detector 16 which detects the deterioration of ground fault or insulation generated at the power lines 4a and 4b or the loads 12a and 12b, and a controller for controlling to open and close the switches, arranged at the power lines connected with the load during an operation stop to specify the ground fault position, when a ground fault is detected by the ground fault detector 16. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a ground fault response device that identifies a ground fault location generated in a power distribution system and separates the ground fault location from the power distribution system.

Conventionally, for example, a non-grounded three-phase AC power distribution system has been adopted in a power distribution system in a ship. In order to detect a ground fault in a power distribution system in a ship, a ground verification lamp in a power supply panel at each place in the ship is generally used. This ground verification lamp has the advantage that the grounded phase can be easily identified because the presence or absence of a ground fault circuit can be verified by the brightness of the verification lamp.
Further, for example, Japanese Patent Application Laid-Open No. 8-340629 (Patent Document 1) discloses a technique for detecting a ground fault occurring on the load side before load power feeding.
JP-A-8-340629 (page 2-3, FIGS. 1-3 and 7)

  However, in the above-described conventional technology, even if the presence or absence of a ground fault occurring in each phase can be detected, a specific ground fault location cannot be automatically identified. For this reason, there is a problem that a worker has to perform specific ground fault location identification and ground fault location separation, which requires enormous time and labor.

  The present invention has been made in order to solve the above-described problem, and is capable of automatically identifying a specific ground fault location and disconnecting the ground fault location while maintaining a stable load operation. An object is to provide a fault countermeasure device.

In order to solve the above problems, the present invention employs the following means.
The present invention includes an opening / closing means disposed on a plurality of distribution lines connecting a power source and a plurality of loads, a ground fault detection means for detecting a ground fault or a decrease in insulation generated in the distribution lines or the load, and the ground Control means for specifying a ground fault location by controlling opening and closing of the opening and closing means arranged in the distribution line to which the load being stopped is connected when a ground fault is detected by the fault detection means; A ground fault countermeasure device comprising:

According to the present invention, the opening / closing means are respectively disposed on the plurality of distribution lines connecting the power source and the plurality of loads. The opening / closing means opens / closes the distribution line in which the self is arranged by being controlled to open / close by the control means. As a result, when the opening / closing means is open, power supply from the power source to the load is cut off.
The ground fault detection means detects, for example, a ground fault or a decrease in insulation based on a change in voltage or current supplied from the power source to the load.
For example, when a ground fault is detected by the ground fault detection unit, the control unit specifies a load during operation stop, temporarily interrupts the supply of power to the specified load during operation stop, The ground fault location is specified according to the state of the power source.
In this way, after a ground fault is detected, each distribution line connecting the power source and the load is shut off to identify the distribution line in which the ground fault has occurred. It becomes possible to specify.
Furthermore, by determining whether or not there is a ground fault preferentially from the load during operation stop, it is possible to efficiently identify the ground fault location without stopping the load during operation wastefully.

In the ground fault countermeasure device described above, the control means detects a current or voltage supplied from the power source while performing open / close control of the open / close means, and refers to the detected current value or voltage value to detect a ground fault. It is preferable to specify the location.
In this way, the ground fault location is identified with reference to the voltage value or current value supplied from the power source to the load, so that the ground fault location can be reliably identified.

In the ground fault countermeasure device described above, it is preferable that the control means opens the opening / closing means disposed on the distribution line related to the identified ground fault location.
Thus, it becomes possible to automatically disconnect the ground fault location from the power source by opening the opening / closing means arranged in the distribution line having the ground fault location.

  The ground fault countermeasure device of the present invention has an effect that a specific ground fault location can be specified and the ground fault location can be automatically separated while maintaining a stable load operation.

Hereinafter, an embodiment of a ground fault countermeasure device according to the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing an outline of a power distribution system in a ship.
As shown in FIG. 1, two generators 1 and 6 are mounted in the ship. The generator 1 is connected to a common bus 3 via a circuit breaker 2. A plurality of distribution lines 4 a and 4 b are connected to the common bus 3. Switches (open / close means) 5a and 5b are interposed between the common bus 3 and the distribution lines 4a and 4b, respectively.
Similarly, the generator 6 is connected to the common bus 8 via the circuit breaker 7. A plurality of distribution lines 9 a and 9 b are connected to the common bus 8. Switches 10a and 10b are interposed between the common bus 8 and the distribution lines 9a and 9b, respectively.

The distribution line 4a and the distribution line 9a are connected to the load 12a via the power switch 11a. The distribution line 4b and the distribution line 9b are connected to the load 12b via the power switch 11b. The power switch 11a selects one of the distribution lines 4a and 9a. Thereby, electric power will be supplied to the load 12a from the distribution line 4a or 9a selected by the power supply switching device 11a. Similarly, the power switch 11b selects one of the distribution lines 4b and 9b. Thereby, electric power will be supplied to the load 12b from the distribution line 4b or 9b selected by the power supply switch 11b.
In such a configuration, the common buses 3 and 8 function as a power source that directly supplies power to the loads 12a and 12b.

  The loads 12a and 12b are provided with sensors 13a and 13b, respectively, for detecting currents flowing to the loads. The sensors 13a and 13b detect currents flowing through the corresponding loads 12a and 12b, respectively, and output the detection results to the data transmission device 14. Based on the result, the data transmission device 14 determines whether the loads 12a and 12b are operating or stopped, and outputs the determination result to the control device 15 described later as operating state information.

The common bus 3 is provided with a ground fault detection circuit 16 that detects a ground fault or a decrease in insulation generated in the distribution line 4a or 4b or the load 12a or 12b. The common bus 8 is provided with a ground fault detection circuit 17 for detecting a ground fault or a decrease in insulation generated in the distribution line 9a or 9b or the load 12a or 12b. The local fault detection circuits 16 and 17 output a ground fault signal to the control device 15 when a ground fault is detected.
As the ground fault detection circuits 16 and 17, a circuit known as a well-known technique can be appropriately adopted according to a design matter or the like. For example, a ground fault detection lamp or a ground fault detection circuit disclosed in JP-A-10-112928 can be employed.

The control device 15 includes, for example, a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory), a RAM (Random
Access Memory). A series of processing steps for realizing various functions to be described later is recorded in a ROM or the like in the form of a program, and the CPU reads the program into the RAM or the like and executes information processing / arithmetic processing. Various functions to be described later are realized.
A display device 18 is connected to the control device 15. The display device 18 displays the image data input from the control device 15 to display, for example, the ground fault location on the display screen.
In the configuration described above, one of the ground fault handling devices according to the present embodiment is configured to include the ground fault detection circuit 16, the switches 5a and 5b, and the control device 15.

  Next, the operation of the ground fault response apparatus according to the present embodiment will be described. Here, the case where a ground fault occurs in the load 12b in the power distribution system shown in FIG. 1 will be described. At this time, it is assumed that the power switch 11a selects the distribution line 4a and the power switch 11b selects the distribution line 4b.

First, when a ground fault occurs in the load 12b, the ground fault is detected by the ground fault detection circuit 16 (“YES” in step SA1 in FIG. 2). When detecting the ground fault, the ground fault detection circuit 16 outputs a ground fault signal to the control device 15 (step SA2).
Since the acquired ground fault signal is a signal from the ground fault detection circuit 16, the control device 15 determines that a ground fault has occurred on the common bus 3 side (step SA3).
Subsequently, the control device 15 sequentially determines whether the loads 12a and 12b are operating or stopped based on the operation state information acquired from the data transmission device 14 (step SA4). Here, it is determined whether or not the vehicle is operating in the order of the loads 12a and 12b.

As a result, when the load 12a is in operation (“NO” in step SA4), it is determined whether or not the next load 12b is in operation (step SA4).
As a result, when the load 12b has been stopped (“YES” in step SA4), the switch 5b Is turned off (step SA5). Thereby, the power supply to the load 12b is interrupted.
Subsequently, in this state, control device 15 determines whether or not the voltage of common bus 3 is normal (step SA6). For example, a voltage sensor (not shown) is provided on the common bus 3, a detection result is acquired from the voltage sensor, and it is determined whether or not the detection result is within a preset normal voltage range.
Here, since the ground fault location is disconnected from the common bus 3 by disconnecting the distribution line 4b from the common bus 3, the voltage of the common bus 3 is restored to a normal value.
Therefore, in step SA6, it is determined that the voltage of common bus 3 is normal (“YES” in step SA6). As a result, the control device 15 specifies the load 12b connected to the distribution line 4b as a ground fault location (step SA8).
When the ground fault location is specified, the control device 15 creates image data for reporting the ground fault location as an image, and outputs the image data to the display device 18. Thereby, the load 12b is displayed on the display screen of the display device 18 as a ground fault location.
As a result, the worker who has confirmed the display device 18 can quickly deal with the ground fault location.

In the above description, the case where the load 12a is in operation has been described. However, if the load 12a has stopped operating, “YES” is determined in Step SA4. In this case, control device 15 turns off switch 5a (step SA5), and determines whether or not the voltage of common bus 3 is normal in this state (step SA6). Here, since the ground fault location is connected to the common bus, the voltage of the common bus is out of the normal range. Therefore, in step SA6, it is determined that the voltage of the common bus 3 is not normal (“NO” in step SA6), and the switch 5a is turned on (step SA7).
And it returns to step SA4 and the process after step SA4 mentioned above is performed about the load 12b.

As described above, the ground fault response device according to the present embodiment has the following effects.
First, since the determination of the presence or absence of the ground fault is performed preferentially from the load during operation stop, it is possible to efficiently identify the ground fault location without stopping the load during operation wastefully. . That is, when a ground fault has occurred in the load during operation stop, it is possible to identify the ground fault location without stopping the load during operation. Thereby, there exists an effect that a specific ground fault location and isolation | separation of the ground fault location can be performed automatically, maintaining the driving | operation of the stable load.
Secondly, the control device 15 detects the voltage of the common bus 3 while performing switching control of the switches 5a and 5b, and identifies the ground fault location based on the detected voltage value. The identification can be performed reliably.
3rdly, since the control apparatus 15 maintains the state which isolate | separated the distribution line which connects the ground fault location and a common bus line from the common bus line, when an earth fault location is specified, an operator's hand is troublesome. Without removing the ground fault, it is possible to continuously supply power stably.

As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.
1stly, the ground fault response apparatus which concerns on this invention is not restricted to the case where it applies to the power distribution system in the ship mentioned above, It is possible to apply to the system | strain which supplies electric power with respect to load from a power supply. .
Second, in step SA6 in FIG. 2, the location of the ground fault is specified depending on whether or not the voltage of the common bus is normal. Instead of or in addition to this, It is also possible to use current or power.
3rdly, although the load and the distribution line were connected via the power supply switching device, the connection form of a distribution line and a load is not restricted to this. For example, the load may be directly connected to the power distribution system.
Fourth, the case where one load is connected to each distribution line has been described, but a plurality of loads may be connected to one distribution line. Further, the number of distribution lines is not limited to two and may be two or more.
Fifth, the control device 15 may be configured by an analog circuit or the like as long as the function described above is realized.

It is a figure which shows the outline of the power distribution system which concerns on one Embodiment of this invention. It is a flowchart which shows operation | movement of the ground fault response apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Generator 2 Circuit breaker 3 Common bus | bath 4a, 4b, 9a, 9b Distribution line 5a, 5b, 10a, 10b Switch 12a, 12b Load 14 Data transmission apparatus 15 Control apparatus 16, 17 Ground fault detection circuit

Claims (3)

Opening and closing means arranged on a plurality of distribution lines connecting a power source and a plurality of loads,
A ground fault detection means for detecting a ground fault or a decrease in insulation generated in the distribution line or the load;
Control for specifying a ground fault location by controlling opening and closing of the opening and closing means arranged in the distribution line to which the load being stopped is connected when a ground fault is detected by the ground fault detection means A ground fault countermeasure device comprising: means.   The control means detects current or voltage supplied from the power supply while performing opening / closing control of the opening / closing means, and identifies a ground fault location with reference to the detected current value or voltage value. The ground fault countermeasure device described.   The ground fault countermeasure apparatus according to claim 1, wherein the control unit opens the opening / closing unit disposed on the distribution line related to the identified ground fault location.

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