KR102386390B1 - Electrical equipment for electrical shock protection and fire prevention of insulated electrical equipment - Google Patents

Abstract

The present invention is specifically directed to electric shock protection and fire prevention of an insulated electric device capable of preventing electric shock and fire due to short-circuit due to water leakage or deterioration of life of an electric device electrically insulated from the ground terminal (Galvanic Isolation). It relates to the device, and in particular, it is an electric device for electric shock protection and fire prevention of insulated electric equipment that monitors the grounding and power lines independently at all times to determine the insulation status of electric equipment, and warns or cuts off the power when an abnormality occurs. is about

Description

Electrical equipment for electrical shock protection and fire prevention of insulated electrical equipment

The present invention relates to an electric device for protection against electric shock and fire prevention of insulated electric equipment, and more particularly, to prevent electric shock and fire due to deterioration of the lifespan of an electric equipment electrically insulated from the ground terminal or electric leakage due to immersion It relates to an electric device for electric shock protection and fire prevention of insulated electric equipment.

In particular, the present invention relates to an electric device for electric shock protection and fire prevention of insulated electric equipment that independently monitors the ground and power line at all times to determine the insulation state of the electric equipment, and to warn or cut off the power when an abnormality occurs. will be.

A power supply is a device that supplies electric power to a predetermined electric device or facility (hereinafter, collectively referred to as “electrical equipment”).

In Korea, the power provided by Korea Electric Power Corporation is usually a three-phase, four-wire system, the line voltage at the final stage is 380V, and the voltage between the line and the neutral line is 220V. In this case, the neutral wire is usually set to have the same potential as the earth.

In general, electrical equipment is grounded for safety to protect the electric equipment when an electric leakage occurs and to remove the risk that may be caused by electric leakage.

In addition, various technologies for preventing electric shock or fire that may be caused by a short circuit or a problem occurring in the power supply system as described above are being developed in a conventional power supply, for example, Patent Documents 1 to 4 there is.

Patent Document 1 discloses a first current having a reference point that is connected to both electrodes of a battery unit and generates a reference voltage according to a potential difference between the electrodes in an electric leakage detection circuit of a power supply device having a battery unit composed of a plurality of batteries. a path, a second current path connected to both electrodes of the battery unit, having three points having different potentials, and a midpoint of the three points connected to the ground through an insulation resistor, and the midpoint of the second current path The first and second comparators that receive voltage from each of the two points to one input terminal and the reference voltage from the reference point of the first current path to the other input terminal, and the outputs of the first and second comparators An earth leakage detection circuit of a power supply device including a detection circuit for detecting the occurrence of an earth leakage based on the

In Patent Document 2, in an electric leakage early warning device in which an input terminal is connected to a non-charged metal body and the opposite terminal is connected to the ground, the lower layer has a thickness of about 0.05 mm as the role of a wire connecting the ground leakage early warning device and the earth connection part. The lower adhesive insulating tape is used for the middle layer, and the lower adhesive electrical conductive tape with a thickness of about 0.07mm is used for the middle layer to be attached to the upper part of the lower insulating adhesive tape, and the upper layer has the same color as the surrounding area where the earth leakage early warning device is installed. It is a three-ply adhesive tape with a total thickness of less than 0.25 mm, which is a three-layer adhesive tape that bonds a colored lower adhesive insulating tape to the upper part of the electrically conductive tape in the middle layer. Make it the same as the surrounding color, and the middle layer is an electric leakage early warning device that does not use a power source and a wire that makes the lower part composed of an adhesive electrically conductive tape act as a wire,

Patent Document 3 discloses a first determiner including an input port to which an output terminal of a first image current transformer is connected, an output port to which an input terminal of a first circuit breaker is connected, a first LAN port and a second LAN port; a second determiner including an input port to which an output terminal of the second image transformer is connected, an output port to which an input terminal of a second circuit breaker is connected, and a first LAN port and a second LAN port; and a main unit connected to the first LAN port of the first determiner by any one LAN cable, wherein the second LAN port of the first determiner and the first LAN port of the second determiner are connected to another LAN cable is connected, and each of the first determiner and the second determiner analyzes the signal input to the input port and outputs a blocking signal to the output port when determining that it is a short circuit, and the main unit is the first determiner and the second determiner It is an earth leakage interrupter system that monitors the condition,

Patent Document 4 discloses at least one end electrically connected to at least one of two or more power lines insulated from the ground, and a first neutral point having a potential between the voltages of the two or more power lines, and the other end electrically connected to the ground. A fault detector including a fault detector, wherein each fault detector limits a leakage current flowing to the ground to a predetermined dangerous current or less and includes a current detection unit for detecting the leakage current, a fault detector electrically connected to a power line among one or more fault detectors is configured so that the current flowing through the fault detector flows in any one of the outflow or inflow directions from the ground, and includes a unidirectional current unit that restricts the current path in one direction so that the current flowing through the fault detector is cut off in a normal state, The detector is an electric shock and fire prevention device that detects a leakage current by forming a current path for a leakage current flowing from two or more power lines or a first neutral point to the ground.

As described above, various technologies for stably supplying power have been developed, and they can prevent electric shock and fire due to a short circuit.

On the other hand, some electrical devices require that the neutral wire is not connected to the ground due to problems such as insulation or safety.

These insulated electrical devices have a grounding terminal that is separate from the power line supplied from the power facility, and the grounding terminal is floating from the power line, and these insulated electrical devices are subject to electric shock due to deterioration of the life of the device or leakage due to flooding. It can prevent overheating and fire, but there is no technology to prevent it.

In particular, there is a problem in that the insulation state of the electric device cannot be grasped as the floating ground and power lines cannot be monitored.

Republic of Korea Patent Publication No. 10-2003-0010582 Republic of Korea Patent Registration No. 10-1420279 Republic of Korea Patent Publication No. 10-2019-0122444 Republic of Korea Patent Registration No. 10-2169232

The present invention was developed to solve the problems of the prior art as described above. Insulation that can prevent electric shock and fire due to deterioration of the lifespan of an electric device electrically insulated from the ground terminal or electric leakage due to immersion The purpose of this is to provide an electric device for electric shock protection and fire prevention of electric equipment.

In particular, the present invention provides an electric device for electric shock protection and fire prevention of insulated electric equipment that independently monitors the ground and power line at all times to determine the insulation state of the electric equipment, and to warn or cut off the power when an abnormality occurs. aim to do

The electric device for electric shock protection and fire prevention of an insulated electric device according to the present invention for solving the above object senses the input power supplied to the insulated load, A device that detects and notifies fire, A) a switch connected between two power input terminals and a ground terminal, a protective resistor that prevents excessive current from flowing when the switch is instantaneously connected, and a method that compares the current values flowing through the two protective resistors a controller comprising a comparison means; B) according to the voltage or current output from the controller cut off the power and characterized in that it comprises an output means for sounding an alarm.

The switch consists of first and second selection switches connected in series to each of the input power sources, and the first and second selection switches operate intermittently and do not operate simultaneously.

The protection resistor consists of first and second divider resistors, and the comparator includes a reference voltage generator that generates a reference voltage to be compared with the voltage detected by the divider resistors, and a voltage detected at each resistor and a reference voltage generator. First and second comparators for comparing the generated reference voltages, respectively, and a summer for summing the results of the first and second comparators may be configured.

The first and second dividing resistors act as a means for measuring the magnitude of the current flowing through the first and second selection switches, and a voltage proportional to the current obtained from the divided resistors is applied in the first and second insulating amplifiers. It is desirable to have a resistor arrangement that does not exceed the allowable input voltage.

Preferably, the first and second insulating amplifiers are insulated from the power supply stage.

Since the first and second comparators have a latch function, a warning signal can be maintained when an insulation failure of an electric device occurs.

Preferably, the output means includes a signal transmission means such as a relay drive, an abnormal alarm buzzer, an LED, and the like.

It is preferable to include a divided voltage recording means for storing the divided voltage information obtained from the first and second insulating amplifiers, and to check the insulation deterioration state of the electric device by analyzing the information stored in the divided voltage recording means.

The electric device for electric shock protection and fire prevention of insulated electric equipment according to the present invention has the effect of preventing electric shock and fire due to leakage of electricity due to deterioration of the life of the electric equipment or water immersion.

In addition, the present invention independently monitors the grounding and the power line at all times to determine the insulation state of the electrical device, and when an abnormality occurs, a warning or power is cut off, so that a person operating or using an electrical device is physically connected to the power terminal together with the grounding terminal. When some of them are in contact, there is an effect to prevent personal injury due to electric shock.

In addition, the present invention has an effect that can prevent malfunction of electric equipment due to electrical confusion between the grounding terminal and the power supply terminal as well as preventing the possibility of fire in advance.

1 is a block diagram of a ground-insulated electric device in which a power source 10 and an insulated ground 30 are configured together with an electric device 20. As shown in FIG.
2 is a configuration diagram schematically illustrating an electric shock phenomenon that may occur when the insulation between the power supply 10 and the ground 30 is damaged.
3 is a configuration diagram in which the electric shock protector 50 proposed in the present invention is connected to a power circuit.
4 is a detection loop when the insulation of one of the power lines connected to the power source 10 is damaged.
5 is a detection loop when the insulation of the other wire 12 among the power lines connected to the power source 10 is damaged.

Since the present invention can be practiced by adding various changes, specific embodiments are illustrated in the drawings and will be described with reference to the detailed description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

In describing each figure, like reference numerals have been used for like elements. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

The present invention can prevent electric shocks and fires due to leakage of electricity due to deterioration of the lifespan of electric devices or immersion in water.

1 is a configuration diagram in which the ground 30 and the insulated power supply 10 are connected to the electric device 20, and two wires 11, 12) shows a case in which one wire (11 in the figure) is connected through the conductor 41. At this time, the ground 30 is insulated from the power supply 10, so there is no electrical effect on the object or the human body 40. . In this circuit configuration, when the load 20 is applied to measurement equipment or equipment sensitive to the ground state, the potential of the ground 30 is formed between the potentials of the two wires 11 and 12 connected to the power supply 10, and the floating Since it is a state, only an electric potential is formed and no current flows.

2 is a case in which the insulation between the ground 30 and the power source 10 is damaged, and the damaged insulation between one line 12 of the power source 10 and the ground 30 is expressed as a resistor 31, in which case an object or a human body When 40 comes into contact with the other undamaged one of the two wires 11 and 12 of the power supply 10 through the conductor 41, the dotted line 13 through the power supply 10 and the resistor 31 ) along with a short circuit or electric shock. At this time, the current flowing along the dotted line 13 is as follows.

here,

: 누설전류 또는 감전전류

: Leakage current or electric shock current

: 전원(10)의 한 선(12)과 접지(30) 사 이의 손상된 절연 저항

: Damaged insulation resistance between one wire (12) of power supply (10) and ground (30)

: 물체 또는 인체(40)의 내부저항

: Internal resistance of an object or human body 40

: 전원(10)의 다른 한 선(11)과 물체 또는 인체(40) 사이 도체(41)의 저항

: Resistance of the conductor 41 between the other wire 11 of the power supply 10 and the object or human body 40

A fire or electric shock accident may occur due to such leakage current, and the present invention proposes a circuit configuration for detecting the occurrence of insulation damage between the power supply 10 and the ground 30 and protecting the system and human life.

3 is a representative view of the present invention, in which only the two wires 11 and 12 of the power supply 10 and the ground 30 are connected in parallel while the circuit connection of the conventional ground-insulated electric device as shown in FIG. 1 is maintained. can be used by First, the first selection switch 511 and the first divider resistor 521 are connected in series to the ground 30 to the terminal connected to one of the power lines 11 of the power supply 10, and the first divider resistor 521 is distributed A voltage across the resistor R11 is connected to the first insulating amplifier 531 . Similarly to the terminal connected to the other line 12 of the power supply 10, the second selection switch 512 and the second divider resistor 522 are connected in series to the ground 30, and the second divider resistor 522 is connected in series. A voltage across the division resistor R21 is connected to the second insulating amplifier 532 .

The first and second selection switches operate intermittently and do not operate simultaneously.

The output of the first insulated amplifier 531 is connected to one input terminal of the first comparator 541 and the other input terminal of the first comparator 541 is connected to the output of the reference voltage generator 550, so that the first insulated amplifier If the output of 531 is greater than that of the reference voltage generator 550 , an output of '1' is output, and if the output of 531 is smaller than that of the reference voltage generator 550 , an output of '0' is transmitted to the summer 560 . Section 2 The soft amplifier 532 also operates in the same manner, so that the output of the second isolated amplifier 532 is connected to one input terminal of the second comparator 542, and the other input terminal of the second comparator 542 is a reference voltage generator. It is connected to the output of 550 and sends an output of '1' if the output of the second isolation amplifier 532 is greater than the reference voltage generator 550, and sends an output of '0' to the summer 560 if it is smaller. . The summer 560 sends an output of '1' to the output driver 570 when a signal of '1' is input to any one of the signals of the first comparator 541 and the second comparator 542 . The output driving unit 570 may convert the result of the summer 560 into various signals that can be grasped from the outside and output it. Typically, the internal state is displayed externally with visible signals such as relay driving, LED lamp, buzzer, etc. .

4 is an operation of the present invention for checking a damaged state of insulation between one of the power lines 12 and the ground 30 among the power lines connected to the power source 10 by operating the first selection switch 511 to operate the first distribution resistor. A voltage (V1) across the division resistor (R11) of (521) is obtained. If a resistor 31 is formed due to insulation damage between one line 12 of the power supply 10 and the ground 30 , the voltage across both ends of the distribution resistor R11 of the first distribution resistor 521 is expressed as follows.

가 충분히 크다면 분배저항(R11)에서 얻어지는 분배전압

은 무시할 수 있는 작은 값이 될 것이다. 한편 도4에서 제2선택스위치(512)는 오픈상태에 있으므로 분배저항(R21)의 전압(V2)은 나타나지 않는다. 얻 어진 분배전압(V1)은 기준전압생성기(550) 전압보다 크면 절연 이상 상태로 판단하 고 출력구동부(570)을 통해 상태(580)를 알린다. Here, if the insulation resistance

If is large enough, the division voltage obtained from the division resistor R11

will be a negligible small value. Meanwhile, in FIG. 4 , since the second selection switch 512 is in an open state, the voltage V2 of the distribution resistor R21 does not appear. If the obtained division voltage V1 is greater than the voltage of the reference voltage generator 550 , it is determined as an insulation abnormal state, and the state 580 is notified through the output driver 570 .

5 shows the second distribution by operating the second selection switch 512 as an operation of the present invention for checking a damaged state of insulation between the other one of the power lines 11 and the ground 30 among the power lines connected to the power source 10. A voltage V2 across the divider resistor R21 of the resistor 522 is obtained. If a resistor 32 is formed due to insulation damage between one line 11 of the power supply 10 and the ground 30, the voltage across the divider resistor R21 of the second divider resistor 522 is expressed as follows. .

이 충분히 크다면 분배저항(R21)에서 얻어지는 분배전압

은 무시할 수 있는 작은 값이 될 것이다. 한편 도5에서 제1선택스위치(511)는 오픈상태에 있으므로 분배저항(R11)의 전압(V1)은 나타나지 않는다. 얻 어진 분배전압(V2)은 기준전압생성기(550) 전압보다 크면 절연 이상 상태로 판단하 고 출력구동부(570)을 통해 상태(580)를 알린다. Here, if the insulation resistance

If is large enough, the division voltage obtained from the division resistor R21

will be a negligible small value. Meanwhile, in FIG. 5 , since the first selection switch 511 is in an open state, the voltage V1 of the distribution resistor R11 does not appear. If the obtained division voltage V2 is greater than the voltage of the reference voltage generator 550 , it is determined as an insulation abnormal state, and the state 580 is notified through the output driver 570 .

Although the present invention has been described with respect to a single-phase circuit, this technology can be sufficiently and easily applied to a polyphase circuit including three phases.

In addition, the voltage obtained from each insulation amplifier can be applied to the comparator, and information on the insulation deterioration status can be obtained by monitoring the voltage transition.

The output means is a means for notifying the outside when a short circuit due to insulation abnormality is detected, and receives signals such as relay driving information, an alarm buzzer, and an alarm LED to notify the outside.

Preferably, the output means includes a communication module to transmit an alarm to a remote terminal.

In addition, although the present invention describes the configuration and operation method for a single phase, it can be easily understood that the same operation method can be applied to a three phase. That is, the present invention is a proposal that can be generally used for single-phase and three-phase and higher constants, and application of a multi-phase system does not depart from the scope of the present invention.

10: power
11, 12: Power supply line drawn from the power source
13: leakage current flow
20: electrical equipment (load)
21: load system
22: ground wire
30: ground
31: ground low antibody
40: object or human body
41: conductor wire
50: electrical device
511, 512: first and second selection switches
521, 522: first and second distribution resistors
531 and 532: first and second isolation amplifiers
541, 542: first and second comparators
550: reference voltage generator
560: summer
570: output driver
580: output switch

Claims (6)

It is an electric device that detects the input power supplied to the insulated load and detects and notifies the electric shock or fire due to a short circuit when the insulated electric device fails.
The first and second divider resistors through the first and second select switches in series with the input power, respectively, and the first and second insulating amplifiers for measuring the voltage divided by the first and second divider resistors; First and second comparators for comparing the voltage detected by the second insulating amplifier with the reference voltage generator, respectively, a summer for summing the results of the first and second comparators, and an output switch for outputting the result of the summer Electric device for electric shock protection and fire prevention of insulated electric devices, characterized in that. According to claim 1,
The first and second selection switches operate intermittently and do not operate at the same time. According to claim 1,
The first and second dividing resistors act as a means for measuring the magnitude of the current flowing through the first and second selection switches, and a voltage proportional to the current obtained from the divided resistors is applied in the first and second insulating amplifiers. An electric device for electric shock protection and fire prevention of insulated electric equipment, characterized in that it has a resistance arrangement that does not exceed the allowable input voltage. According to claim 1,
Since the first and second comparators have a latch function, an electric device for electric shock protection and fire prevention of an insulated electric device, characterized in that it maintains a signal when an insulation failure of the electric device occurs. According to claim 1,
The output switch is an electric device for electric shock protection and fire prevention of an insulated electric device, characterized in that it comprises a signal transmission means such as relay driving, an abnormal alarm buzzer, and LED lighting. According to claim 1,
An electric device for electric shock protection and fire prevention of insulated electric equipment, characterized in that it is provided with means for recording the divided voltage obtained from the first and second insulated amplifiers, and thus checks the insulation deterioration state of the electric equipment.

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