KR102349343B1 - Switchboard having three phases open and netural line protecting function - Google Patents

Abstract

The present invention relates to a switchboard having a three-phase missing and N-phase protection function to detect three-phase commercial power and an N-phase voltage to determine a missing phase. According to the present invention, the switchboard comprises: a rectification unit (110); a reference voltage and comparison voltage applying unit (120); a neutral potential detection unit (180); a first comparator (130) outputting a first level signal when a first comparison voltage (Vcomp1) is lower than a first reference voltage (Vref1); a phase missing detection voltage applying unit (140); a second comparator (150) outputting the first level signal when a second comparison voltage (Vcomp2) is lower than a second reference voltage (Vref2); and a relay driving unit (170) controlled and switched by the output signal of the second comparator (150).

Description

Switchboard with 3-phase phase loss and N-phase protection {SWITCHBOARD HAVING THREE PHASES OPEN AND NETURAL LINE PROTECTING FUNCTION}

The present invention relates to a switchboard having a three-phase loss and N-phase protection function, and more specifically, by detecting a phase loss and an N-phase abnormal state of three-phase commercial power supplied to a three-phase load device such as an electric motor, for example. It relates to a switchgear having a 3-phase phase loss and N-phase protection function so that action can be taken quickly.

A three-phase load device (motor) may fail to rotate normally due to a physical overload, but the main cause is a flashover due to poor insulation or a phase loss due to poor contact of the magnetic contactor.

Therefore, there is a need for a device to check and alert in real time whether there is a phase loss and N-phase disconnection due to the insulation state of the three-phase load device and the poor contact state of the magnetic contactor.

However, in the prior art, when even one phase of the three-phase commercial power line is out of phase, it is detected and appropriately taken. It was prevented from occurring, but it was not possible to detect an abnormal state such as disconnection of the N-phase, so that problems such as damage to the load device due to overvoltage could not be solved.

As a specific prior art, Patent No. 10-0161835 discloses a plurality of full-wave rectifiers that apply 60Hz three-phase power to each phase to connect a current transformer when driving a motor, and full-wave rectify the secondary-side current of the current transformer by means of a diode. a plurality of current/voltage converter units for converting the current output from the full-wave rectifying unit connected to each phase to a voltage; , a plurality of comparators for receiving the operational amplifier connected to each phase and the power supply voltage VCC as inputs, a switch selector for a user to select single-phase or three-phase, and an output and a phase selector switch for the comparator connected to each phase A plurality of inverting buffers for receiving the phase signal selected in the unit as an input, a plurality of light emitting diode units for receiving an output signal from the inverting buffers connected to each phase, a comparator connected to the T and S phases, and a switch selection unit A first AND gate for receiving a signal output from the R phase, a comparator and a switch selector connected to the R phase, and a second AND gate for receiving a signal output from the first and gate, and an output signal of the second and gate Disclosed is an overcurrent relay for phase loss protection comprising a fourth inversion buffer for receiving and a relay driver for driving a relay by receiving a signal output from the fourth inversion buffer, but there is a disadvantage in that there is no N-phase protection function.

The present invention has been made to improve the problems related to the prior art as described above, and an object of the present invention is to detect a phase loss and an N-phase abnormality by detecting a three-phase power supply and an N-phase voltage using a monitoring terminal. An object of the present invention is to provide a switchgear having a 3-phase phase loss and N-phase protection function so as to secure a driving power source for a detection circuit.

Another object of the present invention is to provide a switchgear having a three-phase phase loss and N-phase protection function, in which a driving power source for a three-phase phase loss detection and an N-phase abnormality detection and detection circuit is implemented as a simple circuit.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. There will be.

A switchboard having a three-phase forming and N-phase protection function of the present invention for achieving the above object,

In detecting the three-phase commercial power and N-phase voltage to determine whether a phase is open, and to quickly cut off the commercial power and N-phase voltage and the load terminal,

a rectifying unit 110 for rectifying the three-phase commercial power and outputting a rectified voltage;

A first resistor R1 and a second resistor R2 connected in parallel with the rectifying unit 110 to generate a first comparison voltage Vcomp1 by first dividing the rectified voltage and connected in series with each other, the second A reference voltage including a third resistor R3 and a first capacitor C1 connected in parallel with the second resistor R2 to generate a first reference voltage Vref1 by integrating the voltage applied to the resistor R2 and a comparison voltage applying unit 120;

a neutral potential detection unit 180 configured to have a neutral potential equal to 1/2 of the voltage rectified by the rectifying unit 110 and set to be the same potential as the neutral potential N in a normal state;

The first reference voltage Vref1 is applied to the non-inverting terminal (+) and the first comparison voltage Vcomp1 is applied to the inverting terminal (-), respectively, so that the first comparison voltage Vcomp1 is the first reference voltage Vref1 If it is lower than, the first comparison unit 130 for outputting a signal of a first level;

A fourth resistor (R4) and a third capacitor (R4) and a third capacitor ( C3), connected in parallel with the rectifier 110 to generate a second comparison voltage Vcomp2 by dividing the rectified voltage by a second voltage, and a fifth resistor R5 and a sixth resistor R6 connected in series with each other ) having a phase loss detection voltage applying unit 140;

The second reference voltage Vref2 is applied to a non-inverting terminal (+) and the second comparison voltage Vcomp2 is applied to an inverting terminal (-), respectively, so that the second comparison voltage Vcomp2 is the second reference voltage ( Vref2), a second comparator 150 for outputting the signal of the first level; and

and a relay driving unit 170 configured to be switched by being controlled by the output signal of the second comparator 150 .

In the present invention, the neutral potential detection unit 180 is characterized in that it is composed of a transistor (TR1), resistors (R10 to R12), and a capacitor (C5).

In the present invention, the resistance (R10) and the resistor (R11) of the neutral line potential detection unit are configured to have the same resistance value so that the neutral potential is 1/2 of the voltage rectified by the rectifying unit 110, and in a normal state It is characterized in that it is set to a constant value + range so that the transistor TR1 is not driven in consideration of voltage fluctuations.

In the present invention, the relay driving unit is characterized in that the three-phase commercial power and N-phase applied to the overcurrent circuit breaker and the circuit breaker connected to the load terminal disposed between the circuit breaker to operate.

In the present invention, the phase loss detection voltage application unit 140 removes the ripple voltage applied to the driving voltage of the first comparison unit 130 and the second comparison unit 150 and provides a constant voltage. (130) and a second capacitor (C2) and a Zener diode (Z1) connected in parallel with the input terminal of the second comparator 150 are further included.

In the present invention, the relay driving unit 170 is connected in parallel with the rectifying unit 110, and a relay coil and a switching element connected in series with each other; It includes a relay coil and a fourth capacitor connected in parallel to the switching element, wherein the switching element is controlled by the output of the second comparator 150 .

In the present invention, the switching element is characterized in that any one of a thyristor, a bipolar junction transistor (BJT), a field effect transistor (FET), a TRIAC, and a phototransistor.

According to the switchboard having a three-phase loss and N-phase protection function of the present invention, it is possible to detect a phase loss by detecting the three-phase commercial power and N-phase voltage using the monitoring terminal and secure the driving power for the phase loss detection circuit at the same time. let it be

In addition, the manufacturing cost can be reduced by implementing the driving power supply for the phase loss detection and phase loss detection circuit as a simple circuit.

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a switchgear circuit diagram having a three-phase phase loss and N-phase protection function according to a first embodiment of the present invention;
2 is a waveform diagram of a main part of a switchboard having a three-phase phase loss and N-phase protection function according to the first embodiment of the present invention.
3 is a circuit diagram of a switchgear having a three-phase phase loss and N-phase protection function according to a second embodiment of the present invention.
A clear embodiment of the present invention is shown through the drawings and will be described in more detail in the following content. These drawings are not intended to limit the scope of the spirit of the present invention in any way, but to enable those skilled in the art to understand the concept of the present invention with reference to specific embodiments.

Additional objects, features and advantages of the present invention may be more clearly understood from the following detailed description and accompanying drawings.

Prior to the detailed description of the present invention, the present invention can make various changes and can have various embodiments, and the examples described below and shown in the drawings are not intended to limit the present invention to specific embodiments. No, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

When an element is referred to as being “connected” or “connected” to another element, it is understood that it may be directly connected or connected to the other element, but other elements may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present specification, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Also, terms such as “unit”, “unit”, and “module” described in the specification mean a unit that processes at least one function or operation, which may be implemented as hardware or software or a combination of hardware and software.

In addition, in the description with reference to the accompanying drawings, the same components are given the same reference numerals regardless of the reference numerals, and the overlapping description thereof will be omitted. In describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

[First embodiment]

1 is a circuit diagram of a switchgear having three-phase phase loss and N-phase protection functions according to a first embodiment of the present invention. 2 is a waveform diagram of a main part of a switchboard having three-phase phase loss and N-phase protection functions according to the first embodiment of the present invention.

The switchgear having a three-phase phase loss and N-phase protection function according to the first embodiment of the present invention includes a rectifier 110 , a reference voltage and comparison voltage application unit 120 , a first comparison unit 130 , and a phase loss detection voltage application It may include a unit 140 , a second comparison unit 150 , a relay driving unit 160 , and a contact unit 170 .

The rectifier 110 rectifies the three-phase commercial power and N-phase voltage.

The reference voltage and comparison voltage applying unit 120 integrates the voltage applied to the resistor R2 to generate a first reference voltage Vref1 by a resistor R3 and a capacitor C1 connected in parallel with the resistor R2. It is configured and connected in parallel with the rectifier 110 to generate a first comparison voltage Vcomp1 by first dividing the rectified voltage, and a resistor R1 and a resistor R2 connected in series with each other are configured.

The first comparator 130 receives a first reference voltage Vref1 to a non-inverting terminal (+) and a first comparison voltage Vcomp1 to an inverting terminal (-), respectively, to obtain a first comparison voltage Vcomp1 When it is lower than the first reference voltage Vref1, an “H” signal is output.

The phase-loss detection voltage applying unit 140 integrates the output waveform of the first comparator 130 to generate the second reference voltage Vref2, and a resistor R4 connected in series between the output terminal of the first comparator 130 and the ground. ) and a capacitor C3 are configured, and are connected in parallel with the rectifier 110 to generate a second comparison voltage Vcomp2 by second dividing the rectified voltage, and a resistor R5 and a resistor R6 connected in series with each other are is composed

The phase loss detection voltage application unit 140 removes the ripple voltage applied to the driving voltages of the first comparison unit 130 and the second comparison unit 150 and then provides a constant voltage. 2 A capacitor C2 and a Zener diode Z1 connected in parallel with the input terminal of the comparator 150 may be configured.

The second comparison unit 150 receives the second reference voltage Vref2 to the non-inverting terminal (+) and the second comparison voltage Vcomp2 to the inverting terminal (-), respectively, so that the second comparison voltage Vcomp2 is When it is lower than the second reference voltage Vref2, as shown in FIG. 2, an “H” signal is output.

When the output waveform of the second comparator 150 is an “H” signal, the relay driving unit 160 turns on the control terminal of the switching device, and a current flows through the relay RL to operate the contact unit 170 . .

1, MCCB is an overcurrent circuit breaker, and CB1 and CB2 are circuit breakers.

On the other hand, the switchboard referred to in the present invention should be understood as a concept including a conventional switchboard and a distribution board.

The operation of the switchboard having the three-phase loss and N-phase protection function of the present invention configured as described above will be described as follows.

First, when the three-phase commercial power supply and the N-phase voltage are in a normal state, a waveform such as “IC1 input” of the left waveform of FIG. 2 is applied to the inverting terminal (-) of the first comparison unit 130, and the first comparison unit Reference numeral 130 denotes "IC1 output" of the left waveform of FIG. 2 when the first comparison voltage Vcomp1 applied to the inverting terminal (-) is lower than the first reference voltage Vref1 applied to the non-inverting terminal (+) and Outputs the same "H" signal.

As described above, since the output waveform in the form of a pulse is applied to the non-inverting terminal (+) of the second comparator 150 , the second reference voltage Vref2 charged in the capacitor C3 is always higher than the second comparison voltage Vcomp2 . low.

Accordingly, the output of the second comparator 150 always outputs an “L” signal, and the switching element of the relay driving unit 160 does not operate.

On the other hand, when one phase of the commercial power supply is phase-open, a waveform such as “IC1 input” of the right waveform of FIG. 2 is applied to the inverting terminal (-) of the first comparator 130, and the first comparator 130 is inverted When the first comparison voltage Vcomp1 applied to the terminal (-) is lower than the first reference voltage Vref1 applied to the non-inverting terminal (+), "H", such as "IC1 output" of the right waveform of FIG. output a signal.

As such, since the output waveform in the form of a square wave is applied to the non-inverting terminal (+) of the second comparator 150 in the phase forming section, the second reference voltage Vref2 charged in the capacitor C3 can maintain a predetermined level. .

Therefore, since the output of the second comparator 150 maintains the "H" signal for a predetermined time in the phase loss section, the switching element of the relay driving unit 160 operates, and accordingly, the contact unit 170 is separated and the load terminal is disconnected. It can be separated from the commercial power supply.

In addition, even if the neutral wire is in an abnormal state such as a disconnection, it is determined as an image loss, and a waveform such as “IC1 input” of the right waveform of FIG. 2 is applied to the inverting terminal (-) of the first comparator 130 .

When the first comparison voltage Vcomp1 applied to the inverting terminal (-) is lower than the first reference voltage Vref1 applied to the non-inverting terminal (+), the first comparator 130 determines the " Output an "H" signal, such as "IC1 output".

Therefore, since the output waveform in the form of a square wave is applied to the non-inverting terminal (+) of the second comparator 150 in the disconnection section, the second reference voltage Vref2 charged in the capacitor C3 may maintain a predetermined level.

Therefore, since the output of the second comparator 150 maintains the "H" signal for a predetermined time in the disconnection section, the switching element of the relay driving unit 160 operates, and accordingly, the contact unit 170 is separated and the load terminal is disconnected. It can be separated from the commercial power supply.

On the other hand, whether a phase such as disconnection of the neutral wire is open, for example, a method of checking whether the voltage and/or earth voltage of the neutral wire is detected, a method of determining whether the voltage of the neutral wire and each phase is unbalanced, and the A and B points of the neutral wire It can be selected from a method of measuring the voltage of

[Second embodiment]

3 is a configuration diagram of a switchboard having three-phase phase loss and N-phase protection functions according to a second embodiment of the present invention.

In the second embodiment, the neutral wire potential detection unit 180 including the transistor TR1, resistors R10 to R12, and the capacitor C5 in the configuration of the first embodiment is additionally configured.

The resistor R10 and the resistor R11 are configured to have the same resistance value, and the neutral potential is configured to be 1/2 of the voltage rectified by the rectifier 110, and in a normal state, the transistor ( Set it to a slight + range so that TR1) is not driven.

That is, if 1/2 of the voltage rectified by the rectifier 110 is the same as the + potential and the - potential of the AC waveform, the voltage is set to be the same as the neutral potential N.

Therefore, if the neutral wire N is disconnected, a potential difference occurs between the rectified neutral voltage and the neutral wire N, so that the base current flows through the resistor R12 in the transistor TR1 and the capacitor C5 acts as a noise filter, A delay operation that nullifies the value is performed. It is to operate only in the 60Hz component.

Therefore, since the neutral wire N is an AC component, the transistor TR1 is also switched on/off in the form of a square wave, and this switching operation changes (disturbing) the input of IC1 shown in FIG.

That is, when the neutral line N fluctuates to zero (0)V or more, the values of the resistors R1 and R2 of the reference voltage and comparison voltage applying unit 120 are changed.

Accordingly, a waveform such as "IC1 input" of the right waveform of FIG. 2 is applied to the inverting terminal (-) of the first comparison unit 130, and the first comparison unit 130 is applied to the inverting terminal (-) of the first comparison unit 130 When the voltage Vcomp1 is lower than the first reference voltage Vref1 applied to the non-inverting terminal (+), an “H” signal, such as “IC1 output” of the waveform on the right of FIG. 2 , is output.

As such, since the output waveform in the form of a square wave is applied to the non-inverting terminal (+) of the second comparator 150 in the phase forming section, the second reference voltage Vref2 charged in the capacitor C3 can maintain a predetermined level. .

Therefore, since the output of the second comparator 150 maintains the "H" signal for a predetermined time in the phase loss section, the switching element of the relay driving unit 160 operates, and accordingly, the contact unit 170 is separated and the load terminal is disconnected. It can be separated from the commercial power supply.

The embodiments described in the present specification and the accompanying drawings are merely illustrative of some of the technical ideas included in the present invention. Therefore, since the embodiments disclosed in the present specification are for explanation rather than limitation of the technical spirit of the present invention, it is obvious that the scope of the technical spirit of the present invention is not limited by these embodiments. Modifications and specific embodiments that can be easily inferred by those skilled in the art within the scope of the technical spirit included in the specification and drawings of the present invention should be interpreted as being included in the scope of the present invention.

MCCB: overcurrent breaker CB: circuit breaker
110: rectifying unit 120: reference voltage and comparison voltage applying unit
130: first comparison unit 140: phase loss detection voltage applying unit
150: second comparison unit 160: relay driving unit
170: contact unit 180: neutral wire potential detection unit

Claims (7)

In determining whether a phase is missing by detecting the three-phase commercial power and N-phase voltage, and quickly shutting off the three-phase commercial power and the N-phase voltage and the load terminal,
a rectifying unit 110 rectifying the three-phase commercial power supply and the N-phase voltage to output a rectified voltage;
A first resistor R1 and a second resistor R2 are connected in parallel with the rectifier 110 to generate a first comparison voltage Vcomp1 by first dividing the rectified voltage and are connected in series with each other, and the second A reference voltage including a third resistor R3 and a first capacitor C1 connected in parallel with the second resistor R2 to generate a first reference voltage Vref1 by integrating the voltage applied to the resistor R2 and a comparison voltage applying unit 120;
a neutral potential detection unit 180 configured to have a neutral potential equal to 1/2 of the voltage rectified by the rectifying unit 110 and set to be the same potential as the neutral potential N in a normal state;
The first reference voltage Vref1 is applied to the non-inverting terminal (+) and the first comparison voltage Vcomp1 is applied to the inverting terminal (-), respectively, so that the first comparison voltage Vcomp1 is the first reference voltage Vref1 a first comparator 130 for outputting a signal of a first level when it is lower than;
A fourth resistor R4 and a third capacitor (R4) and a third capacitor ( C3), a fifth resistor R5 and a sixth resistor R6 connected in parallel with the rectifier 110 to generate a second comparison voltage Vcomp2 by second dividing the rectified voltage, and connected in series with each other ) having a phase loss detection voltage applying unit 140;
The second reference voltage Vref2 is applied to the non-inverting terminal (+) and the second comparison voltage Vcomp2 is applied to the inverting terminal (-), respectively, so that the second comparison voltage Vcomp2 is the second reference voltage ( Vref2), a second comparator 150 for outputting the signal of the first level; and
A switchboard having a three-phase loss and N-phase protection function including a; a relay driving unit 170 configured to be switched by being controlled by the output signal of the second comparator 150 . The method according to claim 1,
The neutral wire potential detection unit 180 is a switchgear having a three-phase loss and N-phase protection function, characterized in that it is composed of a transistor (TR1), resistors (R10 to R12), and a capacitor (C5). 3. The method according to claim 2,
The resistor R10 and the resistor R11 are configured to have the same resistance value to configure the neutral potential to be 1/2 of the voltage rectified by the rectifier 110, and in a normal state, the transistor TR1 in consideration of the voltage fluctuation ) is set to a certain value + range so that it is not driven. The method according to claim 1,
The relay driving unit
A switchboard having a three-phase open-circuit and N-phase protection function, characterized in that it operates a contact part disposed between the overcurrent breaker to which the three-phase commercial power and N-phase are applied and the circuit breaker connected to the load terminal. The method according to claim 1,
The phase loss detection voltage applying unit 140 is
The first comparator 130 and the second comparator 150 remove the ripple voltage applied to the driving voltage of the first comparator 130 and the second comparator 150 and provide a constant voltage. A switchgear having a three-phase phase loss and N-phase protection function, characterized in that it further comprises a second capacitor (C2) and a Zener diode (Z1) connected in parallel with the input terminal of the . The method according to claim 1,
The relay driving unit 170 is
a relay coil and a switching element connected in parallel with the rectifier 110 and connected in series with each other;
and a fourth capacitor connected in parallel with the relay coil and the switching element,
wherein the switching element is controlled by the output of the second comparator (150). 7. The method of claim 6,
The switching element is
A switchboard with three-phase loss and N-phase protection, characterized in that it is any one of a thyristor, a bipolar junction transistor (BJT), a field effect transistor (FET), a TRIAC, and a phototransistor.

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