KR20150066013A - High resistance grounding system - Google Patents

Abstract

The present invention relates to a ground accident preventing system. Especially, the present invention is to provide a ground accident preventing system capable of detecting each ground in a condition that a high resistance grounding device and a general grounding device are electrically separated from an insulting transformer. For this, a ground accident preventing system according to the present invention includes a general grounding device which can detect the generation of ground in a power line using three phase power by using a voltage rate; a high resistance grounding device which detects the generation of ground in the power line by using high resistance; an insulating transformer which is installed to the power line and electrically separates the general grounding device from the high resistance grounding device; a power device which is connected to the power line and is driven by the three phase power; and a control device which turns off the driving of the power device according to a ground detection signal transmitted from at least one of the general grounding device and the high resistance grounding device.

Description

{HIGH RESISTANCE GROUNDING SYSTEM}

The present invention relates to a ground fault preventing system, and more particularly, to a ground fault preventing system capable of preventing a ground fault in an electric propulsion system ship using a high voltage.

Vessels are widely used as a means of transportation that accounts for more than half of the world's goods transport. Generally, a ship is dried by using a block drying method in which parts are assembled with a material such as a steel plate, the hull blocks are assembled from these parts, and then the hull blocks are assembled.

As described above, since the ship is manufactured using the same material as the steel sheet, if grounding is caused by the power lines installed on the ship during the operation of the ship, the damage due to the large current may occur, Fire may occur.

Further, in addition to ships, various types of buildings manufactured using steel plates may cause the above-described problems due to grounding.

Therefore, in order to minimize the damage caused by grounding, a grounding device is generally mounted on a ship or a building or the like.

FIG. 1 is a diagram illustrating a configuration of a conventional general grounding apparatus, and FIG. 2 is an exemplary view showing a configuration of a conventional high-resistance grounding apparatus.

A conventional general grounding apparatus is constructed as shown in FIG. 1, and is configured to detect a ground state of a power line constituted by three phases.

In recent years, electric propulsion system ships using high voltage have been manufactured. Such an electric propulsion system ship uses a high voltage, so that it is difficult for the ship to be safely protected from a ground fault by using a conventional general grounding apparatus as shown in Fig.

Therefore, in an electric propulsion system vessel using a high voltage, a high-resistance grounding apparatus as shown in Fig. 2 is used. That is, since the high-resistance grounding apparatus uses a high resistance, it is possible to prevent a large amount of current from flowing through the ship when a ground fault occurs, thereby preventing damage to persons and fire.

However, since a high resistance grounding apparatus has a high failure occurrence rate, an electric propulsion system ship using a high voltage can not be safely protected from a ground fault by using only a high resistance grounding apparatus.

Therefore, a ground fault prevention system for preventing a ground fault by using both the general ground apparatus and the high resistance ground apparatus has been proposed.

However, the conventional ground fault preventing system in which the general grounding apparatus and the high resistance grounding apparatus are simply combined has the following problems.

For example, the common grounding apparatus and the high-resistance grounding apparatus are both grounded to detect a ground fault. Therefore, when the general grounding apparatus and the high-resistance grounding apparatus are simply connected to detect a ground fault, the general grounding apparatus can determine that a ground fault has occurred in the high-resistance grounding apparatus connected to the ground, It can be determined that a ground fault has occurred in the general grounding apparatus connected to the ground.

Accordingly, the conventional ground fault preventing system in which the general grounding apparatus and the high resistance grounding apparatus are combined can not be normally operated.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the above problems and provides a ground fault preventing system capable of detecting a ground fault in a state where a high resistance grounding apparatus and a general grounding apparatus are electrically separated by an insulation transformer .

In order to solve the above-described problems, the present invention can include the following configuration.

A ground fault preventing system according to the present invention includes: a general grounding device capable of detecting whether a ground fault occurs in a power line using three phase power using a voltage ratio; A high resistance grounding device capable of detecting whether a ground fault occurs in the power line using a high resistance; An isolation transformer mounted on the power line for electrically isolating the common grounding device from the high-resistance grounding device; A power device connected to the power line and driven by the three phase power; And a controller for turning off the driving of the power device according to a ground fault detection signal transmitted from at least one of the general grounding device and the high resistance grounding device.

Here, the isolation transformer may convert the voltage applied to the power line and supply the converted voltage to the general grounding unit.

The common grounding apparatus may further include a sensing unit for sensing whether a ground fault occurs in the power line using a voltage transmitted through the insulation transformer; And a test unit for detecting whether or not a ground fault has occurred in the power line and outputting information about occurrence of a ground fault when the control signal is inputted.

Here, when the control signal is input to the test unit, the power device may be continuously driven.

According to the present invention, the following effects can be obtained.

First, since the high-resistance grounding device and the general grounding device can individually detect whether a ground fault occurs, a ground fault can be prevented in advance.

Second, the administrator can arbitrarily test whether a ground fault has occurred by using the general ground apparatus, and visually confirm the occurrence of the ground fault. Therefore, it is possible to thoroughly prevent a ground fault.

Third, since a high-resistance grounding device is used, the amount of current flowing out to a ship when a ground fault occurs can be reduced in an electric propulsion system ship using a high voltage, thereby preventing a large-scale human injury and a large- .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exemplary view showing a configuration of a conventional grounding apparatus; FIG.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]
3 is a block diagram of a system for preventing a ground fault according to an embodiment of the present invention.

It should be noted that, in the specification of the present invention, the same reference numerals as in the drawings denote the same elements, but they are numbered as much as possible even if they are shown in different drawings.

Meanwhile, the meaning of the terms described in the present specification should be understood as follows.

The word " first, "" second," and the like, used to distinguish one element from another, are to be understood to include plural representations unless the context clearly dictates otherwise. The scope of the right should not be limited by these terms.

It should be understood that the terms "comprises" or "having" does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, Means any combination of items that can be presented from more than one.

Hereinafter, preferred embodiments of a spray can treatment apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a block diagram of a system for preventing a ground fault according to an embodiment of the present invention.

Since the ship is manufactured using the same material as the steel sheet, if grounding is caused by the power lines installed on the ship during the operation of the ship, the damage due to the large current may occur, have. In addition to vessels, the above-described problems can also be caused by grounding in various types of buildings manufactured using steel plates or the like.

The present invention is a system for preventing grounding accidents as described above, and can be installed in ships, buildings, and the like. However, for convenience of description, the present invention will be described below as an example of a ground fault prevention system applied to an electric propulsion system ship using a high voltage.

The features of the present invention will be briefly described as follows.

First, the ground fault current can be suppressed to a minimum in order to prevent the danger of personal injury and fire due to a large current when a ground fault occurs. That is, since the present invention uses a high-resistance grounding device, it is possible to limit the ground fault current to a minimum by a high resistance during a ground fault, thereby preventing a power failure.

Second, according to the present invention, whether or not a ground fault has occurred can be detected in advance by a test before a power failure occurs due to a ground fault. That is, according to the present invention, since the ground fault and the ground fault point can be identified in a state in which the electric power apparatus is continuously operated, fire and personal injury can be prevented in advance. To this end, the present invention utilizes a common grounding device.

In order to perform the function as described above, the ground fault preventing system according to the present invention is characterized in that, as shown in Fig. 3, the ground fault detection system detects a ground fault in a power line using three- (120), a high resistance grounding device (110) capable of detecting ground fault occurrence in the power line using a high resistance, and a high resistance grounding device (110) mounted on the power line, A power device 150 connected to the power line and driven by the three phase power and at least one of the common grounding device 120 and the high resistance grounding device 110, And a control unit 140 for turning off the driving of the power device 150 according to the ground fault detection signal transmitted from any one of the plurality of power devices.

First, the general grounding apparatus 120 detects whether a ground fault occurs in the power line, and is connected to each of the three lines R, S, T constituting the power line.

The general grounding apparatus 120 can detect whether or not a ground fault has occurred in the power line, and when a control signal for checking whether a ground fault has occurred is detected, whether the ground fault has occurred in the power line is detected, And may output the information about the information.

To this end, the general grounding apparatus 120 includes a sensing unit 121 for sensing whether a ground fault occurs in the power line using a voltage transmitted through the isolation transformer 130, And a test unit 122 for detecting whether or not a ground fault has occurred in the ground.

The sensing unit 121 senses three general sensing units GF RX and GF connected to each of the three lines R, S and T constituting the power line through the isolation transformer 130, SX, GF TX).

The sensing unit 121 generates a ground detection signal that can determine whether a ground fault occurs in the power line using the voltage ratio transmitted from the isolation transformer 130.

For example, the voltage generated by the current flowing through the three lines of the power line is increased or decreased while passing through the isolation transformer 130, and three voltages that are boosted or reduced are connected to the sensing unit 121 .

The three general sensing units constituting the sensing unit 121 generate a ground detection signal capable of determining whether a ground fault occurs in the power line using the voltages.

The ground fault detection signal sensed by the sensing unit 121 is transmitted to the controller 140.

That is, when a ground fault occurs in the power line, the magnitude of the voltage sensed by the sensing unit 121 may vary. Therefore, the sensing unit 121 generates a ground fault detection signal corresponding to the voltage and transmits the generated ground fault detection signal to the controller 140.

Secondly, the test unit 122 may be used when a manager who senses a ground fault preventing system according to the present invention wants to check whether a ground fault has occurred in the power line through a test.

For example, the control device 140, which receives a ground fault detection signal from the general grounding device 120 or the high resistance grounding device 110 and determines whether a ground fault has occurred in the power line, Even if the information is not outputted, the manager can confirm whether or not the ground fault has occurred for the safety of the ship.

In this case, the manager can turn on the switch (ETS) formed in the test unit 122. [ When the switch ETS is turned on, the test unit 122 is driven.

The test unit 122 includes three test sense units connected to each of the three lines R, S, and T constituting the power line through the isolation transformer 130.

When the switch ETS is turned on, the three test sense units are driven and the ground sense signals sensed through the test sense units are applied to the three output units 227, 228, 229). The three output devices 227, 228, and 229 may be formed of a lamp such as a light emitting diode (LED).

For example, if a ground fault is not generated in the power line, even though the switch ETS is turned on, the three output devices 227, 228, and 229 composed of a lamp are not turned on. Accordingly, the manager can determine that no ground fault has occurred in the power line.

However, if at least one of the three output units 227, 228, and 229 is turned on after the switch ETS is turned on, the manager may determine that a ground fault has occurred in the power line .

In this case, the manager can take measures to find the position where the ground fault has occurred, and can take various measures to prevent ground fault.

The method of finding the position where the ground fault occurs can be variously performed.

For example, the manager may turn off each of the devices constituting the power device 150 and check whether a ground fault has occurred by using the test unit 122. That is, if any of the output devices is not turned on in the state where any one device is off, the manager can determine that a ground fault has occurred in the power line connected to the device that is turned off.

In this case, the manager can check the power lines connected to the apparatus in more detail, thereby confirming the exact position where the ground fault occurred, and then take countermeasures against ground fault occurrence.

The power device 150 may be continuously driven while the control signal is input to the test unit 122 and the ground fault in the power line is tested. That is, since the sensing unit 121, the high-resistance grounding unit 110, the control unit 140, and the power unit 150 are independent from each other, , The power device 150 can be continuously driven while the ground fault is detected in the power line.

Therefore, according to the present invention, it is possible to determine whether a ground fault has occurred in the power line in a state where the power device 150 is continuously driven.

In more detail, the test unit 122 may include a ground lamp and a ground test button (ETS). In this case, if the test button (switch) is depressed, the presence or absence of a ground fault state for each phase can be visually detected through the brightness of the lamp (output device).

Next, the high resistance grounding apparatus 110 performs a function of detecting whether a ground fault has occurred in the power line using a high resistance.

The high resistance grounding apparatus 110 includes three high resistances 200 OHM connected to each of the three lines R, S and T constituting the power line.

The high resistance grounding device 110 includes high resistance sensing devices UCR (R), UCR (S), and UCR (R) connected to each of the three lines R, S, (T), MAIN OCR1, MAIN OCR2, MAIN OCR3).

The ground fault detection signals sensed by the high resistance sensing devices are transmitted to the controller 140.

Next, the isolation transformer 130 is mounted on the power line, and performs a function of electrically separating the common grounding device 120 and the high-resistance grounding device 110 from each other.

If the high-resistance grounding device 110 and the common grounding device 120 are connected through the power line without the isolation transformer 130, the high-resistance grounding device 110 is connected to the common grounding device 120 Detects that a ground fault has occurred, and transmits a ground fault detection signal indicating that a ground fault has occurred to the controller (140). Also, the general grounding apparatus 120 detects that a ground fault has occurred in the high resistance grounding apparatus 110, and transmits a ground detection signal indicating that a ground fault has occurred to the control apparatus 140. 3, both the general grounding apparatus 120 and the high-resistance grounding apparatus 110 are connected to the ground. Therefore, the general grounding apparatus 120 is connected to the high-resistance grounding apparatus 110, The high resistance grounding unit 110 detects that a ground fault has occurred in the general grounding unit 120 and transmits the ground detection signal to the control unit 140. [

However, in the present invention, since the general grounding device 120 and the high-resistance grounding device 110 are electrically separated by the insulation transformer 130, no malfunction occurs as described above.

The isolation transformer 130 converts a voltage applied to the power line and supplies the converted voltage to the general grounding unit 120.

In this case, the sensing unit 121 of the general grounding apparatus 120 generates a ground-fault sensing signal that can determine whether or not a ground fault occurs in the power line using the voltage ratio transmitted from the isolation transformer 130, To the control device (140).

Next, the power device 150 is connected to the power line and driven by the three-phase power, and various devices can be applied.

For example, the power device 150 may be various types of electronic devices mounted on and driven by the electric propulsion system ship.

Lastly, the controller 140 determines whether a ground fault has occurred in the power line using the ground fault detection signal transmitted from the high-resistance grounding apparatus 110 or the general grounding apparatus 120.

The control device 140 controls the high resistance sensing devices UCR (R), UCR (S), UCR (T), MAIN OCR1, MAIN GF RX, GF SX, and GF TX) of the general grounding device 120 and the general sensing devices GF RX, GF SX, and GF TX of the common grounding device 120. [

The controller 140 analyzes the received ground fault detection signals to determine whether a ground fault has occurred in the power line.

If it is determined that a ground fault has occurred in the power line, the controller 140 transmits a turn-off signal to the power device 150 to turn off the power device 150.

In this case, the manager can check whether or not a ground fault has occurred by sequentially turning off each of the devices constituting the power device 150, using the control device 140.

For example, if no information indicating that a ground fault has occurred is output from the controller 140 in a state where any one of the apparatuses is off, the manager determines that a ground fault has occurred in the power line connected to the apparatus that is turned off can do.

In this case, the manager can check the power lines connected to the apparatus in more detail, thereby confirming the exact position where the ground fault occurred, and then take countermeasures against ground fault occurrence.

The present invention described above is summarized as follows.

The reason why the high resistance grounding device 110 is used in the present invention is that when the power line is grounded and an instantaneous overvoltage occurs, the ship or the factory facility or the building is safely protected from the overvoltage, It is to prevent power outage and fire. That is, since the high resistance grounding apparatus 110 uses a high resistance, even if a ground fault occurs in the power line, an overvoltage is not applied to a point where a ground fault occurs.

The reason why the general grounding apparatus 120 is used in the present invention is to assist the high-resistance grounding apparatus 110 while executing the above-described test.

The main functions of the present invention are as follows.

First, preventive maintenance is possible because it can detect in advance when a short circuit occurs.

Secondly, when a complete ground fault occurs, a failure point can be confirmed by using the test unit 122 without causing the power device 150 to be charged. That is, in a ground fault detection system in which a conventional high-resistance grounding apparatus is used, when the circuit grounding due to the general grounding test is detected during operation of the high-resistance grounding apparatus, The power source of the electric propulsion was lost and the ship could be exposed to a dangerous situation by turning off the entire power system. However, according to the present invention, since the test 122 and the high-resistance grounding apparatus 110 can be independently driven, whether or not a ground fault occurs in the power line even in a state in which the power device 150 is driven Can be judged.

Third, transient overvoltages that may occur at the time of ground fault when ARC occurs can be reduced.

Fourth, an alarm may be generated immediately upon initial grounding.

Fifth, the power device 150 can be continuously operated even in a broken line.

Sixth, accurate defect points can be grasped.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Will be clear to those who have knowledge of.

110: high resistance grounding device 120: general grounding device
130: Isolation transformer 140: Control device
150: power device

Claims (4)

A general grounding device capable of detecting a ground fault in a power line using three phase power using a voltage ratio;
A high resistance grounding device capable of detecting whether a ground fault occurs in the power line using a high resistance;
An isolation transformer mounted on the power line for electrically isolating the common grounding device from the high-resistance grounding device;
A power device connected to the power line and driven by the three phase power; And
And a controller for turning off the driving of the power device according to a ground fault detection signal transmitted from at least one of the general grounding device and the high resistance grounding device. The method according to claim 1,
Wherein the isolation transformer comprises:
Wherein a voltage applied to the power line is converted and supplied to the general grounding device. The method according to claim 1,
The general grounding apparatus includes:
A sensing unit for sensing whether a ground fault occurs in the power line using a voltage transmitted through the isolation transformer; And
And a test unit for detecting whether or not a ground fault has occurred in the power line and outputting information on occurrence of ground fault when a control signal is inputted. The method of claim 3,
Wherein when the control signal is input to the test unit, the power device is continuously driven.

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