KR100572624B1 - Wire capacity overload detection circuit and power cut-off device - Google Patents

Abstract

The circuit breaker (N.F.B) to protect the distribution line from overload and the earth leakage circuit breaker (E.L.B) to protect human life from electric shock accident,

The conventional circuit breaker protects the power distribution line by turning off electricity only when a line current of a predetermined rated current (eg, 300 A) or more flows, and the conventional ground circuit breaker also has a rating of more than a predetermined rated leakage current (eg, 100 mA). Only when the leakage current flows, the trip is cut off to protect people from the leakage and electric shock.

That is, the electricity is cut off only when there is a result of an overload accident and a short circuit accident.

However, in the present invention, unlike the conventional circuit breaker, the measured value is calculated by measuring the voltage and the current, and the power line communication (PLC) is compared with each other at the power transmission and reception terminals of the distribution line to predict the capacity overload accident of the distribution line immediately before an accident occurs. It is to cut off the electricity in advance, and unlike the current leakage circuit breaker, the current leakage current of the distribution line and the electric equipment and the electric shock current of the human body are distinguished to cut off the electricity if the electric shock is lower than the rated leakage current (for example, 100 mA).

According to the present invention, a voltage is measured by a transformer PT, a line current of each phase is measured by a current transformer CT, an analog measurement value is converted into a digital value, input to a microprocessor, and arithmetic processing by a program. Electronic circuits and circuit breakers are configured to compare and recalculate digital values by exchanging the calculated digital values with other circuit breakers of power distribution lines or power receivers through power line communication.

The circuit breaker of the present invention prevents wire capacity overload accidents that may occur in a distribution line connected to a load side even under a rated current (eg 300 A),

In addition, the earth leakage breaker of the present invention has a leakage current generated from a distribution line or an electric device even under a rated leakage sensitivity current (eg, 100 mA), an earth leakage current of a wire or an electric device caused by an accident, and an electric shock by human contact. In the case of electric shock by dividing the current, it is effective to cut off the electricity (OFF) to reduce the casualty damage.

Circuit breaker, power transmitter, power receiver, voltage fluctuation, power line communication (P.L.C), wire capacity, resistance temperature coefficient, leakage current, leakage current, electric shock current,

Description

OVERLOAD LOAD SENSITIVE CIRCUIT AND POWER SUPPLY CUTOFF APPARATUS HAVING THEREOF

1 is a schematic view of the wire capacitance overload detection circuit and the power cut-off device of the present invention,

FIG. 2 is a block diagram of the circuit of FIG. 1.

3 is a part of a detailed circuit diagram according to the embodiment of FIG. 1, which is a power line communication (P.L.C) part, an interface part, a power supply part, and a TRIP output part.

4 is a part of a detailed circuit diagram according to the embodiment of FIG. 1, which is a measurement sensing portion of a voltage V, a line current A, and an arc.

FIG. 5 is a part of a detailed circuit diagram according to the embodiment of FIG. 1, which is an analog-digital converter and an operation processing control part.

6 is an example of the electrical distribution panel and trunk diagram of the apartment complex,

FIG. 7 is an electrical piping and wiring system diagram of trunk lines in FIG. 6 and constituted with the power interrupting device of the present invention.

[8] it will summarize the relationship between the transmission end and the number of distribution lines in the wire between the front end temperature (℃) and the line resistance (Ω),

FIG. 9 is a diagram illustrating the relationship between the line current A and the voltage V variation in FIG. 8.

FIG. 10 illustrates the difference between the line currents A of the transmission and reception terminals according to the generation positions of the electric shock current and the leakage current.

11 is a basic program flow diagram of a wire capacitance overload detection circuit and a power cut-off device according to an embodiment of the present invention.

12 is an equivalent circuit of electrical modeling of the human body divided into a hand and a body.

13 is for explaining the characteristics of the leakage current, the leakage current and the electric shock current.

[Figure 14] is a simplified clean the line resistance (Ω) and line temperature (℃) calculated on the basis of a voltage (V) and the line current (A) measured at the can end and the transmission of [8] the front end, related to formula 8 is an example of the solution.

<Description of the code | symbol about the principal part of drawing>

10; Electric power cut-off device for overload cut-off of wire capacity of the present invention

101; A power cut-off device for the power transmission terminal 102; Power cutoff device of power receiver

11; Manual operation lever 111; Power supply

12; Bimetals 121; Voltage detector

13, 14, 15; Current transformers (C.T) 123; Arc detector

124, 132, 142, 152; Amplifier 16; Analog / digital converter

161; A / D converter 17; Arithmetic processing unit

171; TRIP output section 172; Operation status display part

173; Microcontroller 18; Power Line Communication (P.L.C) Modem

19; Interface 20; Electronic Circuit Board (P.C.B)

The present invention relates to a circuit breaker (NFB) that protects a distribution line from overload and an earth leakage circuit breaker (ELB) that protects human life from electric shock.These circuit breakers and earth leakage breakers have different uses, but they are all connected to the distribution line. In addition, there is also an overload circuit breaker (ELB) that combines them.

Conventional circuit breaker (NFB or ELB) uses a thermally operated bimetal or internal magnetic current measurement method to measure only one line current by analog method, and is larger than the rated current (e.g. 300A). Since the line current is distinguished by only a small amount, electricity is cut off only when excessive line current of more than the rated current (eg 300 A) flows.

If the line current (A) flowing through the distribution line is larger than the allowable current (A) of the distribution line but less than the rated current (A) of the circuit breaker because of the above line current classification method, the conventional circuit breaker does not cut off electricity, and thus the distribution line has no heat. It will continue to generate capacity overload.

That is, the conventional circuit breaker turns off electricity only when there is an excessive line current A greater than the rated current A.

In addition, the conventional earth leakage breaker (ELB) is also an electronic circuit using an image current transformer (ZCT) to measure only one current leakage current by an analog method, so that the current leakage current is distinguished only by being smaller than the rated current leakage sensitivity current (eg 100 mA). Electricity is cut off only when leakage current of more than sensitivity current (eg 100mA) occurs.

Conventional earth leakage circuit breakers are classified according to the above ground fault current classification method without any distinction between basic leakage current of power distribution lines and electrical equipment, current leakage due to breakdown and insulation breakdown of power distribution lines and electrical equipment, and electric shock current of human contact. Since electricity is cut off only when a leakage current of more than a sensitivity current (eg, 100 mA) is generated, there is a problem in that an unnecessary hypersensitivity operation due to a leakage current or a malfunction that does not cut off electricity due to a small electric shock current often occurs.

The technical problem of the present invention in order to point out and improve the problem of the conventional circuit breaker (N.F.B or E.L.B) will be described in the example of FIG.

If a 250A line current flows due to a wire (e.g. 50mm2) with an allowable current of 190A on the load side of a conventional breaker with a rated current of 300A, the conventional breaker is not blocked because it is less than the rated current (e.g., 300A). Electric wires (eg 50 mm2) are overloading capacity that generates heat due to exceeding wire allowable currents (eg 190 A).

Heat generation in a distribution line (eg 50 mm2) is related to heat dissipation and cooling, but also to the current density (A / mm2) of the distribution line. When the current density (A / mm2) is 43 to 60, it is ignited. If it is -70, it will melt after ignition, and if it is 75-120, it will ignite simultaneously with the melt.

Whether the distribution line generates heat due to its high current density (A / mm2) or generates heat due to external wiring conditions and ambient temperature, the electrical resistance of the distribution line changes when the temperature of the distribution line rises. Increasingly, vinyl chloride, which is the coating insulation of the distribution line, melts and the insulation is broken.

First, the change in the line resistance of the distribution line will be explained.

Copper, the conductor of the distribution line, shows a resistance increase of about 0.00393 when the temperature rises by 1 ℃ from room temperature due to the resistance temperature coefficient caused by the temperature (℃) rise.

If the line resistance at initial b (℃) is called resistance (Rb) and the line resistance when it rises to t (℃) is called resistance (Rt) and calculated by the formula of resistance temperature coefficient,

Line resistance (Rt) = line resistance (Rb) x [1 + 0.00393 x {t (° C) -b (° C)}] (Ω).

That is, when 10 (℃) rises, the line resistance increases about 3.9%, which is 0.0393,

If 100 ° C rises, the line resistance increases by 39%, which is 0.393.

However, based on the actual temperature of 20 ℃, the line resistance of 31% power distribution lines with 0.00393 × (100-20) (℃) = 0.314 will increase.

That is, the wire having a thickness of 20 mm 2 in FIG. 8 has a resistance of about 0.0000862 (m / m), which is R (℃) = 1 ÷ 58 × 1m ÷ 200 mm 2 / m at room temperature at 20 ° C., but increases to 90 ° C. per m Since it has a resistance of 0.0000862 (Ω / m) × {1+ (0.00393 × (90-20)}, that is, 0.00011 (Ω / m), multiplying this by the round-trip length of the distribution line gives the actual line resistance ( Ω ) value of the distribution line. Becomes

And although the end line of the distribution line does not use electricity at all times, since the trunk line of the distribution line should always supply electricity, to measure the line resistance of the trunk line of the distribution line, measure the voltage and current at the both ends of the distribution line. Compute and calculate the drop versus voltage fluctuation.

Since the transmission and reception terminals of the trunk line of the distribution line are far apart, the measured values of voltage (V) and current (A) at each end are converted to digital, exchanged with each other by power line communication (PLC), stored, compared, checked, and arithmetic processing. In this case, the increase in line resistance of the distribution line can be known, and the change in temperature of the distribution line can be known by calculating the increase of the line resistance using the resistance temperature coefficient.

First, the relationship between the distribution line temperature (° C.), the line resistance ( Ω ) and the voltage (V) variation between the power transmission end and the power reception end of FIG. 8 will be described.

Since voltage drop = power supply voltage (V)-power supply voltage (V) = line current (A) x line resistance ( Ω ),

The measured voltage at the transmission stage 220 when the distribution line is a normal or initial overload (V) and if the measured voltage of the can front end 216.55 (V) and a line current of 100 (A) measured, the line resistance (Ω) of the distribution line Is {220 (V) -216.55 (V)} ÷ 100 (A) = 0.0345 ( Ω ),

When the distribution line is overloaded or the ambient temperature rises and the temperature of the distribution line rises to 90 ° C just before melting of the wire covering insulation, the measured voltage of the power supply terminal is 220 (V) and the measured voltage of the power receiver is 215.6 (V). line resistance (Ω) of the distribution line of the track if the current is 100 (a) wherein is a {220 (V) -215.6 (V )} ÷ 100 (a) = 0.044 (Ω).

If the above increase in line resistance is calculated by the resistance temperature coefficient

[{0.044 ( Ω ) ÷ 0.0345 ( Ω )}-1] ÷ 0.00393 = 70.07 ° C.

In other words, if the temperature of the distribution line rises to 70 ° C., there is a risk of melting the vinyl chloride, which is the coating insulation of the distribution line, and the capacity is overloaded.

However, if the thickness of the trunk line of the distribution line is not the same, and the thick and thin wires are mixed and wired, the capacity is overloaded only in the thin wires, and the line resistance is increased. It is not possible to stop the trunk line of the entire distribution line by the capacity overload.

However, a slight increase in the line resistance in the trunk line of the distribution line is expected to cause a capacity overload in a part of the trunk line of the distribution line, so that an increase in the line resistance is expected to be greater or an overload may occur. When a part of the trunk detects an arc or a spark caused by a short circuit, earth leakage, ground fault, or the like, a capacity overload occurs in the trunk of the distribution line.

In order to detect the arc or spark, the magnitude of these arc currents, high frequency characteristics and chattering phenomena of 1 KHz to 10 KHz may be measured by filtering high frequency components with a current transformer (C.T) and an electronic circuit.

Since arcs and sparks exist for a very short time (㎲ to ms), they are accompanied by chattering when arcs and sparks occur. Therefore, before the arcs and sparks are transferred to the covering insulation of the wire, the It is a feature of the patent of the present invention to cut off electricity by detecting it at the beginning of one or two occurrences.

That is, when it is expected that capacity overload occurs in the distribution line between the breaker (101) and the breaker (102) in FIG. 8, the change range of the line resistance becomes larger, or the ⑥ to ⑧ of FIG. If the leakage current (mA ~ A) is detected, the breaker can be immediately disconnected at ⑦, which is one or two occurrences of arc and spark.

The leakage current of ⑥ to ⑧ in Fig. 13 is a high frequency source that generates high frequency with an electric signal along with chattering with arc or spark, and has a frequency characteristic between 1KHz and 10KHz. It can be detected by an electronic circuit.

In addition, the leakage of the distribution line (leakage, leakage, electric shock) will be described.

Leakage current is necessarily generated by the insulation of distribution lines and electrical equipment.

Leakage current is generated when insulation of distribution line or electric equipment is destroyed by moisture or breakdown.

Electric shock current is generated by human body contacting live part of distribution line or electric equipment.

FIG. 10 illustrates a difference between line currents A of a power transmission end and a power reception end according to an electric leakage or electric shock generation position.

In FIG. 10, if the line current at the transmission end of the distribution line is 100.08 (A) and the line current at the power receiving end is 100.03 (A), the leakage current of the distribution line is 0.05 (A) or 50 (mA).

If the leakage current 50 (mA) is not changed after a certain period of time, or if there is no change in the increase or decrease of the electric load, this is a leakage current (㎂ to mA) that is basically generated in a distribution line or an electric device. The minimum ignition current value is approximately 300mA to 500mA.

The changes in line current at the transmission and reception terminals are different according to the leakage current, leakage current, and electric shock current location of FIG. 10, and the current leakage (leakage, leakage, electric shock) is measured at the same time as generation and compared by power line communication. And calculate.

In other words, the line current of the power transmission stage and the line current of the power receiving stage are measured and converted into digital values and transmitted and received to each other by power line communication. The difference between the currents is the leakage current (leakage, leakage, electric shock).

The present invention is to prevent the electric leakage accident and the electric shock accident of the human body by dividing the electric leakage current by the characteristics, and further divided into leakage current, electric leakage current, electric shock current.

In the leakage current described above, the insulation of the distribution line, the home appliance, or the electrical equipment is deteriorated and cured according to the characteristics and the period of use as shown in ① to ② to ⑤ of FIG. It keeps stable mA ~ mA) and increases gradually with the use period.

The leakage current described above is a chatter that is caused by partial breakdown of insulation due to moisture or failure of an insulation of a distribution line or an electric device, as in ⑤ to ⑦ to ⑧ of [Fig. 13]. In addition to the ring phenomenon, arc (ARC) current or ground fault current due to arc (ARC) or spark (SPARK) is generated.

The electric shock current (mA) is generated by the contact between electricity and the human body as shown in Figs. 13-13, and rapidly increases and becomes unstable after the chattering phenomenon occurs at least once at the same time as the human body contacts. This phenomenon is caused by the struggle of the human body and the resistance and capacitance of the human body.

Of the body of electric shock current, as its electrical modeling of the human body [12] Inductive reactance phase of electric shock current into a more capacitive-a large reactance (X _C) (X _L) is while a lead of 90 degrees than the voltage much high frequency And noise.

In addition, the magnitude of each leakage current (leakage, leakage, electric shock) is also distinguished.

Leakage current is usually several mA to several tens of mA, leakage current is usually several mA to several hundred A, and human body electric shock current is usually several mA to several tens of mA.

Therefore, after measuring the leakage (leakage, leakage, electric shock) current, magnitude, surge and fluctuation, slope, frequency, phase and time difference, chattering, etc. and digitally calculating the leakage (leakage, leakage, electric shock) current It can be distinguished.

The present invention is not limited to the power interruption device for capacity overload and earth leakage breaker, but is not limited to the embodiments, but not only the circuit breaker (NFB) and the earth leakage breaker (ELB) but also a large capacity breaker, a line breaker, Applicable to outlets and power strips, respectively, it can be changed in various ways.

The "capacitance overload detection circuit and short circuit detection circuit" are abbreviated as "sensing circuit", and the "capacitance overload blocking and power interrupter 10" is made as a "power interrupter 10".

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

In addition, the same code | symbol is used in the same part and repeated description is abbreviate | omitted.

To measure the voltage (V), line current (A) and phase time (위상) of a distribution line supplied with commercial power to achieve the present invention, the measured values are stored and compared using a microcontroller, a semiconductor. Treatment is effective.

The time difference of the phase 1 ° is 46.3 ms.

In addition, the microcontroller can also communicate, it is easy to measure the microsecond (기를) because the time can be measured using an oscillator of 10MHz (0.1kHz) or more.

FIG. 1 is a whole of a power supply interrupting device for electric wire overload interrupting and breaking according to the present invention, and a sensing circuit is mainly composed of an electronic circuit board 20, and various semiconductors and electronic components such as a microprocessor and an A / D converter. Consists of.

(11) is a manual operation lever, (12) is a thermally operated bimetal,

(13), (14) and (15) are current transformers (C.T) and are installed for each phase to measure the line current (A),

(121) is a transformer (P.T) and measures the voltage (V),

(171) is the TRIP output part of the sensing circuit and consists of trip coil or solenoid and converts the electrical control signal of the sensing circuit into mechanical operation (10) manual operation of the power cut-off device. The lever can be turned off, or a relay can be used to issue a warning signal or flash the warning lamp.

Reference numeral 18 denotes a power line communication modem, which is used for connecting communication data to a power line (hundreds of hundreds to hundreds of thousands of volts) using the power line coupler of 181, but is configured for hundreds (V) in the present invention.

Reference numeral 19 denotes an interface unit configured to connect (18) a power line communication (P.L.C) modem and (17) an operation processor with communication and an electrical signal.

2 is a block diagram illustrating the operation of the power cut-off device, and (11) a block diagram of the sensing circuit except for the manual operation lever and (12) the bimetal.

3 is a detailed view of the power supply portion of the sensing circuit, 111 is a power transformer, and 112 is a rectifier and a portion for supplying DC power used for the sensing circuit.

Reference numeral 172 is an operation state display unit configured with LEDs for displaying the measurement result of the detection circuit and the power on / off state.

4 is a detailed view of the measurement detection portion of the detection circuit, and measures the power supply side voltage at 121, and the reference numeral 123 is an arc detection unit and detects an arc and spark voltage generated in a distribution line.

(131), (141) and (151) are connected to each of (13), (14) and (15) current transformers to measure line current, and (124), (132), (142) and (152). Is the amplification part of each measured value.

5 is a detailed diagram of an analog-digital converter and arithmetic processing unit of a sensing circuit;

(16) The analog-to-digital converter converts analog measurement values of voltage and line current into digital, and (161) mainly consists of analog-to-digital converters.

Reference numeral 17 denotes an arithmetic processing unit which inputs all digital measurement values to a microprocessor, stores and compares them by a program, compares them, and controls them by arithmetic processing. The microprocessor is composed of a microcontroller that is easy to expand communication functions and capacities. In this way, it is possible to efficiently calculate various complicated electrical data with fast calculation and make accurate measurements.

The wire capacitance overload detection circuit configured as described above will be described.

To measure the line resistance (Ω) in the main distribution line of a commercial power source that is supplied to be calculated by measuring the transmission-circuit voltage (V) and a number of front end voltage (V) and current line (A), but

Since the transmitter and receiver are far from each other, the digital values of voltage (V) and current (A) at each end are exchanged with each other by power line communication (PLC), stored, compared, and processed to calculate the line resistance ( Ω ). have.

The increase in the line resistance of the distribution line can be known by the calculation of the line resistance, and the change in temperature of the distribution line can be known by calculating the increase in the line resistance by the resistance temperature coefficient.

In order to easily compare and analyze and transmit and receive all the above measured values, it is efficient to digitize all detected analog values in the (16) analog-to-digital conversion unit and calculate them in the (17) computation processing unit (173) microcontroller.

(17) In the (173) microcontroller of the calculation processing unit, the equations 1), 2), 3) and 4) of [14] related to [FIG. 8] and [FIG. 9] are prepared by a program and input in advance. After comparing the digital value received by power line communication with the digital value of self-measured voltage and line current with (173) microcontroller, the line resistance and temperature (℃) of the distribution line can be obtained. It is to configure the wire capacity overload detection circuit for detecting the capacity overload of the distribution line.

The line resistance of a power distribution line cannot be changed naturally while commercial electricity is supplied. However, the line resistance cannot be changed other than the change due to the resistance temperature coefficient due to the change in the temperature (℃) of the power distribution line. It is a feature of the present invention to measure the temperature (° C.) of a distribution line by measuring it.

To which [14] can be obtained by formula (1)) to the line resistance (Ω) of the formula 4) to calculate the increase in wire resistance as a resistance thermometer can be obtained the temperature (℃) increases.

If the resistance temperature coefficient is 0.00393, the resistance at the initial b (° C) is called Rb ( Ω ), and the resistance at the time of rising to t (° C) is Rt ( Ω ),

Since - [{b (℃) t (℃)} 1 + 0.00393 ×] (Ω), Rt = Rb ×

As shown in the example of Equation 4) in FIG. 14, when the temperature rises to 70 ° C., the temperature of the distribution line itself is 90 ° C., and thus the capacity is overloaded.

The above 70 (℃) temperature rise is when the thickness of the trunk line of the distribution line is constant,

However, if thick and thin wires are mixed and wired, the temperature rise due to capacity overload occurs only in a thin distribution line, and the temperature rises above 70 (℃) only in a thin portion of a distribution line, which is more dangerous than when the thickness of the distribution line is constant. .

Therefore, if capacity overload occurs only in thin distribution lines as described above, arc and sparks are generated due to short circuit and ground fault due to melting of coating insulation of thin distribution lines. An overload is detected.

In addition, the power interruption device for both wire-capacity overload cut-off for achieving another object of the present invention based on the wire-capacity overload detection circuit (11) by adding a manual operation lever and a thermally operated bimetal (12) The electrical control signal of the sensing circuit is converted into a mechanical operation in the TRIP output unit 171 (11) is configured to block the manual operation lever.

The earth leakage detection circuit constructed as described above will be described.

First, the line current of the transmission stage and the line current of the receiver stage are measured as digital values, and then the digital values are transmitted and received to each other by power line communication (173), compared with a microcontroller, and processed. The difference of the preceding line current minus a leakage current (leakage, leakage, electric shock) is a characteristic of the present invention.

As shown in FIG. 10, if the measurement line current of the power transmission stage is 100.08 (A) but the measurement line current of the power receiver is 100.03 (A), the leakage current of this distribution line is 100.08 (A) -100.03 (A) = 50 (mA). to be.

Distinguishing the 50 mA leakage current has been described above, but will be described in detail again.
The leakage current of 50 mA is a difference between the current values measured at the power transmission and reception terminals, which is a leakage, a short circuit, or an electric shock current generated at the distribution line.
The leakage current of 50 mA is reduced in the use of electricity at the power receiving end, the current value is reduced to the same size at the power transmission end, but the difference between the current value of the power supply and the receiving end is equal to 50 mA.
Even if no electricity is used at the power stage, the leakage current of 50 mA always occurs, which is a leakage current that always occurs in distribution lines.
Since the magnitude of the leakage current varies depending on the thickness and length of the distribution line, it is constant as long as the thickness or length of the distribution line does not change, but as time passes, the coating insulation of the distribution line deteriorates and hardens, and the insulation resistance deteriorates inversely. The current gradually increases in size with time.
Such a distribution line becomes an electric leakage current when the coating insulation breaks rapidly, and an electric shock current becomes an electric current when the human body contacts an exposed live part of the distribution line.
The leakage current, leakage current and electric shock current are classified as shown in the following table.

The leakage current is distinguished from the leakage current and the electric shock current. The leakage current is small in size, constant and stable, and is gradually increased with the use period. If the increase rate (%) is small compared to the leakage current value after a certain time by storing the digital value of the leakage current in the microcontroller, the present invention judges it as the leakage current.
That is, if the leakage current value of the distribution line measured first is mA1, the leakage current value measured after a certain time is called mA2, the predetermined time is called T1, and the relative increase value of mA1 and mA2 is mA3, the relative increase value mA3 = mA2-mA1, and the percentage increase over time = {(mA2-mA1) ÷ mA1} ÷ T1, where the percentage of increase over time is very small, leakage current, or leakage current or electric shock current. .
However, the conventional circuit breaker has a inconvenience in that the power supply is cut off unconditionally when the magnitude of the current leakage current is larger than the rated leakage current, but the present invention has the magnitude of the measured leakage current value mA1 or the leakage current value mA2 is larger than the rated leakage current. Even if the relative increase value mA3 and the increase rate (%) over time are small, it is judged as a leakage current and does not cut off a power supply.
At this time, the power supply is not uninterrupted, but when the magnitude of the leakage current value mA1 or the leakage current value mA2 exceeds several times the rated leakage sensitivity current, the leakage current is considered dangerous and the power is turned off.

In addition, the above-mentioned leakage current has a characteristic of generating an arc current or ground fault current by an arc or spark along with a repeated chattering phenomenon, so that an arc is detected by an arc detection unit, and (17) an operation processing unit (173). The microcontroller memorizes the digital value of the leakage current at the beginning and compares it with the leakage current value after a certain period of time.
Above leakage current increases rapidly with relative increase value mA3 even if measured leakage current value mA1 or leakage current value mA2 is smaller than rated leakage sensitivity current, and (123) Arc detection part has arc current or ground fault due to arc or spark. If the current is detected and the repeated chattering phenomenon is also present, this is a leakage current, so the present invention can distinguish it.
In addition, if the arc detection unit detects an arc or spark, it occurs in the distribution line, and a short circuit occurs in the distribution line due to partial breakdown of insulation due to moisture or external influences.

In addition, the electric shock current fluctuates unstable suddenly after the chattering phenomenon occurs at least once at the same time as the contact of the human body, and as shown in the electrical modeling of the human body of FIG. 12, the inductive reactance (X _L Since the capacitive reactance (X _C ) is larger than), the phase of the electric shock current is about 90 degrees ahead of the voltage, and the noise and high frequency are distinguished from the leakage current. 173) The microcontroller measures the magnitude and phase of the current compared to the leakage current, the degree of change of sudden and sudden fluctuations, the repetition of chattering phenomenon, the high frequency and noise, and the characteristics of the electric shock current. If the increase exceeds a certain value, an electric shock is determined.
The above electric shock current increases rapidly while the relative increase value mA3 is increased even though the leakage current value mA1 or the leakage current value mA2 measured in the present invention is smaller than the rated negative operating current value. Therefore, the present invention can distinguish this.
Such an electric shock current fluctuates unstablely after one or two chatterings at the beginning of electric shock, the electric current phase is higher than the voltage, and severe electric noise and high frequency components are generated. If the characteristic appears, (173) calculated by the (173) microcontroller of the calculation processing unit, even if the relative increase value mA3 of the electric shock current is smaller than the rated portion operating current value, if the percentage (%) of the increase over time is large, in the present invention To decide on a dangerous electric shock.

According to the present invention, the leakage current is further subdivided by characteristics, and a detection circuit capable of breaking electricity by dividing the basic leakage current of a distribution line or an electrical device into a leakage current and an electric shock current of a failure or breakdown of a distribution line or an electrical device. To construct.

In addition, the electric power cut-off device for double circuit capacity overload cut-off for achieving another object of the present invention (10) based on the ground fault detection circuit (11) by adding a manual operation lever and a thermally operated bimetal (12) detection circuit By converting the electrical control signal of the TRIP output unit 171 into a mechanical operation (11) is configured to block the manual operation lever.

The present invention has the effect of reducing the capacity overload accident of the distribution line that may occur during the use of electricity in the trunk line of the distribution line, resulting in short-circuit, short circuit and electric shock and human and property damage.

In addition, in the past, an excessively thick distribution line was used by applying an excessive safety factor in order to prevent wire capacity overload accidents. However, in the present invention, if a capacity overload of the distribution line can be sensed to cut off electricity in advance, an appropriate safety factor may be applied. The construction cost can be reduced because it can be constructed by a different distribution line.

And if the breaker of the trunk line of the distribution line is sensitive to the basic leakage current and cut off the electricity, the range of the power failure is wide and the damage is large. Unnecessary power outage can be reduced.

In addition, the power cut-off device of the present invention can know whether the short circuit in the trunk line of the distribution line or the short circuit in the terminal line of the distribution line, it is possible to reduce unnecessary power failure in the trunk line of the distribution line.

The present invention will be a safer power cut-off device in the absence of an electric facility manager, such as a general house or a small factory, business place.

In addition, the conventional circuit breaker cannot distinguish an electric shock current (eg, 10 mA or less) less than the rated leakage current (for example, 100 mA), and thus a malfunction occurs in which the circuit breaker does not cut off electricity. It is an effect of the present invention that the leakage operation, the electric leakage and the electric shock are distinguished by measuring the digital calculation method, so that the operation of the electric leakage breaker during electric shock can be improved, thereby reducing the electric shock damage of the human life.

Claims (6)

In the wire capacity overload detection circuit that can prevent the electrical accident of the capacity and load of the distribution line supplied with commercial power, A power supply unit for supplying operation power to the wire capacitance overload detection circuit; A detector configured to measure voltage and line current for each phase of the distribution line, an amplifier configured to amplify the measured value of the detector, An analog-digital converter configured to convert the analog values detected by the detector and the amplifier into digital values, Comprising a calculation processing unit for storing, comparing, arithmetic processing and controlling the digital value according to the input program, Configure a TRIP output unit that can cut off the supply of commercial power in accordance with the result of the operation processing unit, An operation state display unit for displaying the operation state of the TRIP output unit to the outside; In addition, the wire capacitance overload detection circuit comprises an arc (Arc) detection unit for detecting the arc and spark generated in the distribution line, And configuring a power line communication (P.L.C) unit and an interface unit capable of communicating with another wire capacitance overload detection circuit in a transmission line or a receiving end of a distribution line in the wire capacitance overload detection circuit. The wire capacitance, which transmits the digital value of the voltage and line current of each phase of the distribution line measured by the wire capacitance overload detection circuit to the other wire capacitance overload detection circuit at the power transmission end or the power receiving end of the power distribution line by PLC. With overload detection circuit, By measuring and communicating the voltage and line current of each phase of the distribution line, the temperature rise of the distribution line is calculated to predict the wire capacity overload, Or when the temperature rise in the distribution line is expected to detect the arc and spark generated in the distribution line initially to predict the wire capacity overload, Capacitive overload detection circuit that can prevent capacity overload of distribution line and short circuit, short circuit, ground fault, etc. in advance. In the power cut-off device for both overload capacity, which prevents an electric accident of overload capacity from occurring in a distribution line supplied with commercial power, The wire-capacity overload cut-off power supply has a built-in wire-capacity overload detection circuit according to claim 1, and a manual operation lever capable of manually opening and closing the power supply and a thermally operated bimetal as an auxiliary breaker. Configure the power cutoff device, In the electric power interrupting device for electric wire overload interrupting function which cuts off the power by operating the above manual operation lever with a trip coil (TRIP COIL) or a blocking solenoid (SOLENOID) of the electric wire capacitance overload detecting circuit of claim 1, The digital value of the voltage and line current of each phase of the distribution line measured by the power line disconnecting / breaking device with the wire-capacity overload cut-off is measured by the power line communication (PLC) and other power-capacity overload cut-off power-disconnecting device at the transmission line or the receiving end of the distribution line. It is a power cut-off device for both overload cutoff and transfer value. By measuring and communicating the voltage and line current of each phase of the distribution line, the temperature rise of the distribution line is calculated to predict the wire capacity overload, Or when the temperature rise in the distribution line is expected to detect the arc and spark generated in the distribution line initially to predict the wire capacity overload, This is a power cut-off device for both line capacity overload cut-off that can prevent capacity overloading of distribution lines and short circuits, short circuits, and ground faults. A power supply circuit breaker for electric wire capacity overload interruption, comprising claim 2 as a high capacity circuit breaker, a line breaker, or an outlet or a power strip. In the ground fault detection circuit which can prevent the ground fault of the distribution line supplied with the commercial power supply and the electric shock accident of the human body in advance, A power supply unit for supplying operation power to the ground fault detection circuit; A detector configured to measure voltage and line current for each phase of the distribution line, an amplifier configured to amplify the measured value of the detector, An analog-digital converter configured to convert the analog values detected by the detector and the amplifier into digital values, Comprising a calculation processing unit for storing, comparing, arithmetic processing and control the digital value according to the input program, Configure a TRIP output unit that can cut off the supply of commercial power in accordance with the result of the operation processing unit, An operation state display unit for displaying the operation state of the TRIP output unit to the outside; In addition, the earth leakage detection circuit includes an arc detection unit for detecting arcs and sparks generated from distribution lines, And in the ground fault detection circuit, a power line communication (P.L.C) unit and an interface unit for communicating with another ground fault detection circuit in a power transmission end or a power receiving end of a distribution line, As a ground fault detection circuit, the digital value of the voltage and line current of each phase of the distribution line measured by the ground fault detection circuit is exchanged with the other ground fault detection circuit at the power transmission terminal or the power receiving terminal of the power distribution line by P.L.C. By measuring and communicating the voltage and line current of each phase of the distribution line, By distinguishing the basic leakage current of the distribution line and the leakage current of insulation breakdown and the electric shock current of the human body, In case of electric shock current, the electricity is cut off even under the rated leakage current. If the leakage current of insulation breakdown, the electricity is cut off even under the rated leakage current. In case of basic leakage current of power distribution line or electric equipment, an earth leakage detection circuit that can delay the interruption of electricity until it exceeds a certain limit even above the rated leakage current. This is a power cut-off device for both overload and overload capacity that can prevent short circuits and electric shocks that may occur in distribution lines supplied with commercial power. The power cut-off device for electric wire capacity overload cut-off is built in the electric power cut-off device for electric wire capacity overload cut-off and has a built-in leakage control circuit according to claim 4 and a manual operation lever capable of manually opening and closing the power and a thermal operation type bimetal as an auxiliary cut-off device. Configure In the electric power cut-off device of the electric capacity overload cut-off combined circuit which cuts off a power supply by operating said manual control lever by the trip coil (TRIP COIL) or the blocking solooid (SOLENOID) of the earth leakage detection circuit of Claim 4, The digital value of the voltage and line current of each phase of the distribution line measured by the power line disconnecting / breaking device with the wire-capacity overload cut-off is measured by the power line communication (PLC) and other power-capacity overload cut-off power-disconnecting device at the transmission line or the receiving end of the distribution line. It is a power cut-off device for both overload cutoff and transfer value. By measuring and communicating the voltage and line current of each phase of the distribution line, By distinguishing the basic leakage current of the distribution line and the leakage current of insulation breakdown and the electric shock current of the human body, In case of electric shock current, the electricity is cut off even under the rated leakage current. If the leakage current of insulation breakdown, the electricity is cut off even under the rated leakage current. In case of basic leakage current of power distribution line or electric equipment, power cut-off device for both overload capacity which can delay the cut off of electricity until it exceeds a certain level even above the rated leakage sensitivity current. An electric power interrupting device for wire capacity overload interruption, comprising claim 5 as a high capacity circuit breaker, a line breaker, or an outlet or a power strip.

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