KR102411894B1 - Insulation separation type mechanical latch monitoring protection device of secondary commercial circuit of current transformer for switchgear - Google Patents

Abstract

The present invention relates to an insulation separation type mechanical latch monitoring and protection device for a secondary commercial circuit of a current transformer for a switchgear, and more particularly, to a secondary circuit open accident of a current transformer (CT) used for power in conventional power facilities and power transmission and distribution systems It relates to an insulation separation type mechanical latch monitoring and protection device for a secondary commercial circuit of a current transformer for switchgear that prevents electric shock accidents, plasma arc discharge fire accidents, and malfunctions of protective relays caused by an increase in induced voltage of secondary circuits.
To this end, the present invention provides a control instrumentation unit connected to an R-phase current transformer (CT_R), a T-phase current transformer (CT_T), and an S-phase current transformer (CT_S) installed for each phase from single-phase and three-phase four-wire power equipment, and each phase, respectively. In the insulation separation type mechanical latch monitoring and protection device for a secondary commercial circuit of a current transformer for a switchgear connected in parallel, the insulation separation type mechanical latch monitoring protection device includes an R-phase current transformer (CT_R), a T-phase current transformer (CT_T) and an S-phase current transformer (CT_S) of the input terminal CT_in and one end of (ON) a mechanical latch contactor main contact 110 that is closed according to driving, and a mechanical latch lock is made to maintain a short circuit state; The input terminal (CT_in) and one end of the R-phase current transformer (CT_R), T-phase current transformer (CT_T), and S-phase current transformer (CT_S) are respectively connected, and the other end is an R-phase current transformer (CT_R), T-phase current transformer (CT_T) and S-phase current transformer. an open detection unit connected to the output terminal CT_out of (CT_S) to detect whether the control measuring units of the R-phase current transformer CT_R, the T-phase current transformer CT_T, and the S-phase current transformer CT_S are open; and a forced short circuit unit for forcibly shorting the mechanical latch contactor main contact by turning on the mechanical latch contactor main contact according to the open signal of the open detection unit.

Description

Insulation separation type mechanical latch monitoring protection device of secondary commercial circuit of current transformer for switchgear

The present invention relates to an insulation separation type mechanical latch monitoring and protection device for a secondary commercial circuit of a current transformer for a switchboard, and more particularly, to a secondary circuit open accident of a current transformer (CT) used for power in conventional power facilities and transmission and distribution systems. It relates to an insulation separation type mechanical latch monitoring and protection device for a secondary commercial circuit of a current transformer for switchgear that prevents electric shock accidents, plasma arc discharge fire accidents, and malfunctions of protective relays caused by an increase in induced voltage of secondary circuits.

Current transformers (CTs) are widely used as safety and current measuring means in commonly used power busbars or branch busbars. These current transformers obtain a small current proportional to the large current of the AC, so the measuring range of the AC ammeter used to enlarge

The structure of the current transformer is that a primary coil with a small number of turns and a secondary coil with a large number of turns are wound on a stratified iron core such as a transformer, and measuring devices such as an ammeter, a wattmeter, and a relay are connected to the secondary coil.

In addition, the rated current value of the primary current of the transformer has several forms from several tens of A to several thousand A, but the rated current value of the secondary current is mostly 5A, and the current ratio of the primary and secondary coils is inversely proportional to the number of turns of each coil.

The secondary terminal of the current transformer should always be constructed in a closed loop type to be safe, but if it is opened, it is very dangerous. This is because the primary current of the current transformer is the load current. When the secondary coil is opened, the primary current continuously magnetizes all the iron cores, causing the iron cores to be continuously saturated. because it can

Therefore, when the internal circuit of the measuring instrument such as ammeter or wattmeter connected to the secondary coil of the current transformer is opened or the secondary coil of the current transformer is opened due to other reasons, it can detect this and instantly short the opened secondary terminal. It is necessary to install a circuit with a function on the secondary side of the current transformer.

In addition, CT, which is essential for overcurrent protection in electric power facilities and transmission/distribution power systems, is responsible for electric shock accidents due to the rise of the primary and secondary induced voltages due to magnetic flux saturation from the CT output terminal to the open point in the case of a secondary open accident. It causes major electrical accidents due to noise and vibration, the 3rd, 5th and 7th harmonic characteristics, plasma arc discharge accident, and malfunction of the protective relay.

In addition, after monitoring the openness of the secondary CT commercial circuit, the secondary CT induced voltage is converted into a response current. The problem that the operation failure or malfunction of the main contactor for a forced short circuit is caused by repeated ON/OFF vibrations at the midpoint of the contact point due to the relay's latent current according to the voltage drop characteristic, and the abnormal voltage erasure fails. occurs

In addition, due to this, the generation of third, fifth, and seventh harmonics may be weighted in the secondary wiring and the primary wiring. This chattering malfunction causes a problem of degrading stable forced short-circuit operation in the case of a second CT open accident.

In order to solve this problem, a device for detecting an open current transformer secondary terminal according to Korean Patent Registration No. 10-0644142 has been proposed. As shown in FIG. A circuit protection unit that cuts off the overvoltage by reducing the open circuit voltage of the circuit protection unit, a rectifier unit that rectifies the voltage signal that has passed through the circuit protection unit, and compares the voltage signal output from the rectifier with a preset reference voltage value to open the secondary terminal of the current transformer. A comparator for outputting a voltage signal for , a relay coil generating magnetic induction by current flowing by a voltage signal for the opening of the secondary terminal output from the comparator, and a second breaker of the current transformer by magnetic induction of the relay coil It is composed of a short-circuit switch that short-circuits the ruler.

However, the open detection device has a problem in that there is a risk of aggravating the failure due to the direct connection of a complex control circuit on the CT secondary commercial circuit, and a complicated interference circuit causes inspection and maintenance confusion.

Korean Patent Registration No. 10-0644142

The present invention has been devised to solve the above problems, and in the event of a secondary circuit open accident of a current transformer (CT) used in electric power of conventional power facilities and transmission and distribution systems, the induced voltage of the secondary circuit is increased. The purpose of this is to provide an insulation separation type mechanical latch monitoring and protection device for the secondary commercial circuit of the CT 2 switchgear current transformer to prevent electric shock accidents, plasma arc discharge fire accidents, and non-operation accidents of the protective relay.

The present invention has the following features in order to solve the above problems.

The present invention provides a control instrumentation unit connected to R-phase current transformers (CT_R), T-phase current transformers (CT_T) and S-phase current transformers (CT_S) respectively installed for each phase from 3-phase 4-wire power and for a switchgear panel connected in parallel for each phase In the insulation separation type mechanical latch monitoring protection device of a secondary commercial circuit of a current transformer, the insulation separation type mechanical latch monitoring protection device is an input terminal (CT_in) of an R-phase current transformer (CT_R), a T-phase current transformer (CT_T), and an S-phase current transformer (CT_S) and one end are respectively connected, and the other end is respectively connected to the output terminal (CT_out) of the R-phase current transformer (CT_R), the T-phase current transformer (CT_T) and the S-phase current transformer (CT_S). a mechanical latch contactor main contact 110 that is closed according to and is mechanically latch-locked to maintain a short-circuit state even in the event of a power failure; The input terminal (CT_in) and one end of the R-phase current transformer (CT_R), the T-phase current transformer (CT_T), and the S-phase current transformer (CT_S) are respectively connected, and the other end is an R-phase current transformer (CT_R), T-phase current transformer (CT_T) and S-phase current transformer. an open detection unit connected to the output terminal CT_out of (CT_S) to detect whether the control instrumentation unit of the R-phase current transformer CT_R, the T-phase current transformer CT_T, and the S-phase current transformer CT_S is opened; and a forced short circuit unit for forcibly shorting the mechanical latch contactor main contact by turning on the mechanical latch contactor main contact according to the open signal of the open detection unit.

Here, the open detection unit is connected to the input terminal (CT_in) and one end of the R-phase current transformer (CT_R), the T-phase current transformer (CT_T) and the S-phase current transformer (CT_S), respectively, and outputs the tracking discharge voltage as a discharge pulse current when the control measuring unit is opened. three places of insulating isolation elements, and three bridge rectifying elements connected to the other ends of the three places of insulating isolation elements, respectively, receiving the discharge pulse current output from the insulating isolation element and outputting the rectified pulse pulsating current as input; , Three power storage elements each connected to the output terminals of the three bridge rectifying elements to store a pulse pulsating current, and three open sensing elements connected to the output terminals of the three bridge rectifying elements, respectively, connected in parallel with the power storage element It includes a relay and three open sensing relay a contact points respectively connected to the open sensing relay and switched from an OFF state to an ON state when the open sensing relay is turned on.

In addition, the forced short circuit unit includes a power supply supplying AC or DC power, a mechanical latch contactor coil having an anode and one end connected to the power supply unit, and the other end and one end of the mechanical latch contactor coil connected, and the other end of the three places Each of the open sensing relay contacts a is connected, and when the mechanical latch contactor coil is ON, the open sensing relay 124 is immediately turned OFF, and when the mechanical latch contactor coil is OFF, immediately It includes a mechanical latch contactor b contact that is turned on.

In addition, the positive electrode and one end of the power supply unit are connected and the mechanical latch contactor contact a is turned on according to the ON operation of the mechanical latch contactor coil, and the mechanical latch contactor contact a and one end are connected, and the other end is connected. further includes an open warning lamp connected to the cathode of the power supply unit.

In addition, the positive electrode and one end of the power supply unit are connected and the lockout contactor coil for releasing and opening the mechanical latch lock of the main contact point of the mechanical latch contactor according to the ON operation, and one end at the other end of the lockout contactor coil This connection, the other end further includes a NO (normally open) type latch release manual button connected to the negative electrode of the power supply unit.

In addition, it is connected in parallel with both sides of the open warning lamp to receive the ON driving signal of the open warning lamp, and is connected in parallel to both sides of the latch release manual button to control the ON driving of the lockout contactor coil. A remote control unit is further included.

In addition, the insulating isolation device has a discharge current withstand capacity of 3kA to 10kA, and is any one of a zinc oxide (ZnO) device, a surge suppressor, a surge protector (SPD), or a surge absorber, and the control and instrumentation unit is a R-phase current transformer (CT_R), T-phase current transformer (CT_T), and S-phase current transformer (CT_S) are respectively connected to each phase, or R-phase current transformer (CT_R), T-phase current transformer (CT_R) corresponding to any one selected from three phases ( CT_T) and S-phase current transformer (CT_S) is connected, and the isolation type mechanical latch monitoring and protection device is connected in parallel with the control measuring unit.

According to the present invention, as compared to the conventional CT secondary open monitoring device, as the configuration is more simplified, there is an effect of reducing the production cost and improving the operation reliability.

In addition, in the form of indirect connection through an insulating separation element, it is possible to monitor in an insulated state without directly monitoring the opening of the secondary commercial circuit including the control and measuring part, and when the mechanical latch contactor main contact is short-circuited through the forced short-circuit part As there is no need for a separate power supply to maintain the lock according to the maintenance of the mechanical lock, it has the effect of maintaining a short circuit even in case of low voltage or power failure.

In addition, the existing CT secondary open monitoring device has a complicated circuit as a detection circuit and a blocking circuit are mixed. It works.

In addition, since the latch release manual button can be configured to apply a signal with S/W, there is an effect that the main contact of the mechanical latch contactor can be opened remotely.

1 is a view showing an open detection device of a current transformer secondary terminal in the related art.
2 is a view showing a schematic configuration of an insulation separation type mechanical latch monitoring protection device according to an embodiment of the present invention.
3 is a block diagram showing the internal configuration of an insulation separation type mechanical latch monitoring and protection device according to an embodiment of the present invention.
4 is a circuit diagram of an insulation separation type mechanical latch monitoring protection device according to an embodiment of the present invention.

In order to explain the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, preferred embodiments of the present invention will be exemplified below and will be described with reference to them.

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

In describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

2 is a view showing a schematic configuration of an insulation separation type mechanical latch monitoring and protection device according to an embodiment of the present invention, and FIG. 3 is a view showing the internal configuration of an insulation separation type mechanical latch monitoring protection device according to an embodiment of the present invention It is a block diagram, and FIG. 4 is a circuit diagram of an insulation separation type mechanical latch monitoring protection device according to an embodiment of the present invention.

Referring to the drawings, the insulation separation type mechanical latch monitoring and protection device 100 according to an embodiment of the present invention is largely an R-phase current transformer (CT_R), a T-phase current transformer (CT_T), and an input terminal (CT_in) of the S-phase current transformer (CT_S). and one end are respectively connected, and the other end is respectively connected to the output terminal CT_out of the R-phase current transformer (CT_R), the T-phase current transformer (CT_T), and the S-phase current transformer (CT_S), and the mechanical latch contactor coil 132 is turned ON. ) is closed according to the drive, and the mechanical latch contactor main contact 110 is maintained in a short-circuited state through the mechanical latch lock 111, and the R-phase current transformer (CT_R), the T-phase current transformer (CT_T) and the S The input terminal CT_in and one end of the phase current transformer CT_S are respectively connected, and the other end is respectively connected to the output terminal CT_out of the R-phase current transformer CT_R, the T-phase current transformer CT_T, and the S-phase current transformer CT_S, so that the R phase The mechanical latch contactor main contact point according to the open signal of the open detection unit 120 and the open detection unit 120 for detecting whether the control measuring unit of the current transformer (CT_R), the T-phase current transformer (CT_T), and the S-phase current transformer (CT_S) is opened. It is configured to include a forced short-circuit unit 130 for forcibly short-circuiting by turning the 110 on (ON).

Here, the mechanical latch contactor main contact 110 closes and opens according to the ON driving of the mechanical latch contactor coil 132 and the lockout contactor coil 136 to be described later, respectively. carry out

The mechanical latch contactor main contact 110 is configured as a NO (Normally Open) type so that the current input through the current transformer for each phase is input to the open detection unit 120 side in a normal state, that is, in an abnormal state, that is, the secondary As the commercial circuit is opened, when a discharge accident occurs, the open detection unit 120 detects it, and when the forced short circuit unit 130 shorts the mechanical latch contactor main contact 110, the current input through the current transformer for each phase is to flow into a closed circuit having only the mechanical latch contactor main contact 110 connected to each phase.

Here, the opening of the secondary commercial circuit refers to the control measuring unit 200 that receives the current through the current transformer for each phase, and the control measuring unit 200 includes various measuring instruments, for example, an ammeter, a wattmeter, a power factor meter, These include OCR relays, differential ratios, relays, current converters, meters or composite protection relays.

These various measuring instruments should be connected in series for the low impedance of the control measuring unit 200, and if any one of them is disconnected from the contact terminal or the internal coil unit, the secondary commercial circuit will be in an open state.

Accordingly, the mechanical latch contactor main contact 110 includes a mechanical latch contactor main contact 110 connected in parallel with the control measuring unit 200 to prevent various accidents that may occur when the control measuring unit is opened. This is to block the opening of the control instrumentation section by shorting the closed circuit.

In addition, when the mechanical latch contactor main contact 110 according to the present invention is closed according to the ON driving of the mechanical latch contactor coil 132, the mechanical latch contactor coil 132 is cut off (OFF) ), it is possible to maintain the short circuit state through the mechanical latch lock 111 .

At this time, in order to release the short-circuit state, the mechanical latch lock part 111 is released by manually releasing the mechanical latch lock part 111 or by applying a current to the lockout contactor coil 136 to turn it on. and, accordingly, the mechanical latch contactor main contact 110 is opened.

On the other hand, the open detection unit 120 has one end connected to the input terminal CT_in of the R-phase current transformer CT_R, the T-phase current transformer CT_T, and the S-phase current transformer CT_S, and the other end is an R-phase current transformer CT_R, T-phase. It is connected to the output terminal CT_out of the current transformer CT_T and the S-phase current transformer CT_S, respectively, and configured to detect whether the control instrumentation of the R-phase current transformer CT_R, the T-phase current transformer CT_T, and the S-phase current transformer CT_S is open. The open detection unit 120 is connected to the input terminal CT_in and one end of the R-phase current transformer CT_R, the T-phase current transformer CT_T, and the S-phase current transformer CT_S, respectively, and detects the tracking discharge voltage when the control measuring unit is opened. The three insulating isolation elements 121 outputting the discharge pulse current and the other ends of the three insulating isolation elements 121 are respectively connected to the discharge pulse current outputted from the insulating isolation element 121 and rectified Three bridge rectifying elements 122 outputting the pulsed pulsating current, respectively, connected to the output terminals of the three bridge rectifying elements 122 to charge the pulsed pulsating current, and a storage element 123 for limiting malfunction; , respectively connected to the output terminals of the three bridge rectifying elements 122 and connected to the three open sensing relays 124 and the three open sensing relays 124 connected in parallel with the power storage element 123, respectively. When the open sensing relay 124 is turned on, it includes three open sensing relay a contact 125 that is switched from an OFF state to an ON state.

Here, the insulating isolation element 121 maintains an insulating state in a normal state that is less than 50V to 15kV, which is an open start voltage, and when the control measuring part is opened, when it exceeds the open start voltage due to the tracking discharge voltage, the discharge pulse current is converted into a bridge rectifying device. It is provided to output to the (122) side.

The insulation separation type mechanical latch monitoring and protection device circuit according to the present invention is normally insulated from the control measurement unit through the insulation separation element 121, so that the secondary commercial circuit due to interference with the control measurement unit, that is, the control measurement unit 200 ) can minimize the influence on the circuit, thereby reducing the failure rate of the secondary commercial circuit.

In addition, the bridge rectifying device 122 receiving the discharge pulse current outputs it as a full- wave rectified pulse pulsating current, which is stored through the power storage device 123 connected to the output terminal of the bridge rectifying device 122 .

In addition, the open sensing relay 124 connected in parallel to the output terminal of the bridge rectifier 122 together with the power storage element 123 is driven ON according to the predetermined capacity of the power storage element 123, so that the open detection relay for each phase The a contact 125 is closed.

Such an open detection relay 124 should not have harmonic chattering driven by harmonic AC waves, should not have an operation failure rate due to secondary voltage load characteristics during operation, and should be able to withstand secondary transient voltage. , the above-described bridge rectifying device 122 and the power storage device 123 are provided for this purpose.

In addition, the open sensing relay contact a 125 for each phase is closed according to the ON driving of the open sensing relay 124, and the open sensing relay 124 is biased ( ON), it is a NO (Normally Open) type contact that becomes a short circuit.

As described above, the open detection unit 120 of the present invention is configurable on the PCB, so that the circuit of the insulation-separated mechanical latch monitoring protection device can be configured simply, and the installation space can be reduced.

On the other hand, the forced short circuit 130 is the open signal of the open detection unit 120, that is, the open detection relay 124 according to the ON driving of the open detection relay a contact 125 according to the short circuit (Close) of the It is provided to forcibly short-circuit the control measuring unit by turning on the mechanical latch contactor main contact 110, and the forced short-circuit unit 130 includes a power supply unit 131 for supplying AC or DC power, and the power supply unit ( 131), a mechanical latch contactor coil 132 having one end connected to the positive electrode, and the other end and one end of the mechanical latch contactor coil 132 are connected, and the other end is the open sensing relay a contact point 125 of the three places. are connected to each, and when the mechanical latch contactor coil 132 is biased (ON), the mechanical latch contactor main contact 110 is short-circuited immediately, so that the CT secondary discharge accident voltage is erased, and the mechanical latch contactor b contact 133 This is OFF, and when the mechanical latch contactor coil 132 is turned OFF, the mechanical latch contactor b contact 133, which is immediately turned on, is connected to the positive electrode and one end of the power supply unit 131. and the mechanical latch contactor a contact 134, which is turned on according to the ON operation of the mechanical latch contactor coil 132, and the mechanical latch contactor a contact 134 and one end are connected, The other end has an open warning lamp 135 connected to the negative pole of the power supply unit 131, and one end is connected to the positive pole and one end of the power supply unit 131, and the mechanical latch contactor main contact 110 according to ON driving. A lockout contactor coil 136 for releasing and opening a mechanical latch lock, and one end is connected to the other end of the lockout contactor coil 136, and the other end is connected to the negative electrode of the power supply unit 131 (normally open) It is configured to include a manual latch release button 137 of the type.

Such a forced short circuit 130 is connected to the open detection relay a contact 125 for each phase, and the power supply unit 131 of the forced short circuit unit 130 between each phase open detection relay a contact 125 for each phase. When any one of the three open sensing relay a contact 125 for each phase is short-circuited with the It can be converted to a short-circuit state.

The forced short circuit 130 is connected to the AC or DC power supply unit 131 with the mechanical latch contactor coil 132, the mechanical latch contactor b contact 133, and the open detection relay a contact 125 and opened. When any one of the sensing relay a contact 125 is short-circuited, the mechanical latch contactor coil 132 is turned on and then immediately turned off according to the opening of the mechanical latch contactor b contact 133 .

However, according to the ON driving of the mechanical latch contactor coil 132, the mechanical latch contactor main contact 110 is short-circuited immediately, and is connected to the power supply unit 131, but is connected in parallel with the mechanical latch contactor coil 132 As the mechanical latch contactor a contact 134 is short-circuited immediately, the open warning lamp 135 is also driven ON.

In addition, the lockout contactor coil 136 and the latch release manual button 137 that are connected in parallel with the mechanical latch contactor coil 132 have a lockout contactor coil 136 when the latch release manual button 137 is short-circuited. It is turned on, thereby releasing the short circuit, that is, opening the mechanical latch contactor main contact 110, which is currently in a short circuit state.

The lockout contactor coil 136 is provided to release the locking state of the mechanical latch locking part 111 of the mechanical latch contactor main contact 110. This lockout contactor coil 136 is, for example, a mechanical type It may be composed of a coil portion positioned on the other side of the latch contactor coil 132 to release the mechanical latch contactor main contact 110 .

In addition, as an example, the mechanical latch contactor coil 132, the lockout contactor coil 136, and the mechanical latch contactor main contact 110 are configured in one device to form two coil parts, respectively, the mechanical latch contactor coil 132. and a lockout contactor coil 136 are configured, and the mechanical latch contactor coil 132 is turned ON, that is, the mechanical latch contactor main contact 110 is shorted according to the application of power, and a latch release manual button ( 137) of the lockout contactor coil 136 is turned on, that is, the mechanical latch contactor main contact 110 is opened according to the application of power.

In addition, in the present invention, the remote control unit 140 is installed and connected to both sides of the open warning lamp 135 in parallel to receive the ON driving signal of the open warning lamp 135, and the latch release manual button 137. It may be connected in parallel with both sides of the to control the ON driving of the lockout contactor coil 136 .

The remote control unit 140 receives the on/off of the open warning lamp 135 in real time to monitor it, and to control the ON driving of the lockout contactor coil 136 if necessary according to the monitoring situation. configurable.

In addition, a separate signal transmission configuration is further provided according to the remote distance and may be configured to mediate.

In addition, the insulating isolation device 121 has a discharge current withstand capacity of 3 kA to 10 kA, and a zinc oxide (ZnO) device, a surge suppressor, a surge protector (SPD), or a surge absorber may be applied.

In addition, the control measuring unit 200 is applicable to a single-phase two-wire system or a single-phase three-wire system in addition to the three-phase four-wire system. Any one of the R-phase current transformer (CT_R), the T-phase current transformer (CT_T), and the S-phase current transformer (CT_S) will be connected to .

Of course, the isolation type mechanical latch monitoring and protection device 100 is connected in parallel with the control measuring unit 200 to monitor whether the control measuring unit 200 is opened.

On the other hand, if necessary, the open detection relay 124 driving information is transmitted to a separate computer processor to collect the overall operation state of the insulation-separated mechanical latch monitoring and protection device 100, and the result is monitored externally through a communication module, etc. As it is transmitted to a computer or server, it can be configured to be linked with various other power facilities that are interlocked with the current transformer.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above. That is, a person of ordinary skill in the art to which the present invention pertains can make numerous changes and modifications to the present invention without departing from the spirit and scope of the appended claims, and all such appropriate changes and modifications are Equivalents are to be considered as falling within the scope of the present invention.

100: isolation type mechanical latch monitoring protection device
110: mechanical latch contactor main contact
111: mechanical latch lock
120: open detection unit
121: insulation isolation element 122: bridge rectifier element
123: power storage element 124: open detection relay
125: open detection relay a contact
130: forced short circuit
131: power supply 132: mechanical latch contactor coil
133: mechanical latch contactor b contact 134: mechanical latch contactor a contact
135: open warning lamp 136: lockout contactor coil
137: Latch release manual button
140: remote control unit
CT_R : R phase current transformer CT_T : T phase current transformer
CT_S: S-phase current transformer CT_in: Current transformer input
CT_out : output stage of current transformer

Claims (8)

A control measuring unit 200 connected to an R-phase current transformer (CT_R), a T-phase current transformer (CT_T), and an S-phase current transformer (CT_S) installed for each phase from three-phase, four-wire electric power, and the control measuring unit 200 and each In the insulation separation type mechanical latch monitoring and protection device of a secondary commercial circuit of a current transformer for a switchgear connected in parallel for each phase,
The insulation separation type mechanical latch monitoring protection device 100 is
The input terminal (CT_in) and one end of the R-phase current transformer (CT_R), T-phase current transformer (CT_T), and S-phase current transformer (CT_S) are respectively connected, and the other end is an R-phase current transformer (CT_R), T-phase current transformer (CT_T) and S-phase current transformer. A mechanical type that is respectively connected to the output terminal CT_out of (CT_S), is closed according to the ON driving of the mechanical latch contactor coil 132, and the short circuit state is maintained through the mechanical latch lock unit 111 Latch contactor main contact (110);
The input terminal (CT_in) and one end of the R-phase current transformer (CT_R), T-phase current transformer (CT_T), and S-phase current transformer (CT_S) are respectively connected, and the other end is an R-phase current transformer (CT_R), T-phase current transformer (CT_T) and S-phase current transformer. an open detection unit 120 connected to the output terminal CT_out of (CT_S) to detect whether the control measuring unit 200 of the R-phase current transformer CT_R, the T-phase current transformer CT_T and the S-phase current transformer CT_S is open; and
and a forced short circuit unit 130 for forcibly shorting the mechanical latch contactor main contact 110 by turning on the mechanical latch contactor main contact 110 according to the open signal of the open detection unit 120 .
The open detection unit 120 is connected to the input terminal (CT_in) and one end of the R-phase current transformer (CT_R), the T-phase current transformer (CT_T), and the S-phase current transformer (CT_S), respectively, and detects the tracking discharge voltage when the control measuring unit 200 is opened. The three insulating isolation elements 121 outputting the discharge pulse current and the other ends of the three insulating isolation elements 121 are respectively connected to receive the discharge pulse current outputted from the insulating isolation element 121 and rectify Three places of the bridge rectifying element 122 for outputting the pulsed pulsating current, and three power storage elements 123 connected to the output terminals of the three places of the bridge rectifying element 122 to store the pulsed pulsating current; The three places are respectively connected to the output terminals of the bridge rectifying element 122, and are connected to the three open sensing relays 124 and the three open sensing relays 124 connected in parallel with the power storage element 123, respectively. When the open sensing relay 124 is turned on, it includes three open sensing relay a contact 125 that is switched from an OFF state to an ON state,
The forced short circuit unit 130 includes a power supply unit 131 for supplying AC or DC power, a mechanical latch contactor coil 132 connected to an anode and one end of the power supply unit 131 , and a mechanical latch contactor coil 132 . ) is connected to the other end and one end, and the other end is connected to the three open sensing relay a contact points 125, respectively, and when the mechanical latch contactor coil 132 is turned on, it is immediately turned off. , which includes a mechanical latch contactor b contact 133 that is immediately turned on when the mechanical latch contactor coil 132 is turned off
Insulation separation type mechanical latch monitoring and protection device of secondary commercial circuit of current transformer for switchgear, characterized in that
According to claim 1,
A mechanical latch contactor a contact 134 connected to an anode and one end of the power supply unit 131 and turned on according to an ON operation of the mechanical latch contactor coil 132;
One end of the mechanical latch contactor a contact 134 is connected, and the other end further includes an open warning lamp 135 connected to the cathode of the power supply unit 131 .
Insulation separation type mechanical latch monitoring and protection device of secondary commercial circuit of current transformer for switchgear, characterized in that
3. The method of claim 2,
A lockout contactor coil 136 having one end connected to the positive electrode of the power supply unit 131 and releasing and opening the mechanical latch lock of the mechanical latch contactor main contact 110 according to ON driving;
Further comprising an NO (normally open) type latch release manual button 137 having one end connected to the other end of the lockout contactor coil 136 and the other end connected to the negative electrode of the power supply unit 131 .
Insulation separation type mechanical latch monitoring and protection device of secondary commercial circuit of current transformer for switchgear, characterized in that
4. The method of claim 3,
It is connected in parallel with both sides of the open warning lamp 135 to receive an ON driving signal of the open warning lamp 135,
A remote control unit 140 connected in parallel with both sides of the latch release manual button 137 to control the ON driving of the lockout contactor coil 136 is further included
Insulation separation type mechanical latch monitoring and protection device of secondary commercial circuit of current transformer for switchgear, characterized in that
4. The method of claim 3,
The insulating isolation element 121 is
Discharge current withstand is 3kA to 10kA,
One of a zinc oxide (ZnO) device, a surge suppressor, a surge protector (SPD), or a surge absorber
Insulation separation type mechanical latch monitoring and protection device of secondary commercial circuit of current transformer for switchgear, characterized in that
According to claim 2 or 3,
The control measurement unit 200
R-phase current transformer (CT_R), T-phase current transformer (CT_T) and S-phase current transformer (CT_S) are respectively connected for each phase from the three-phase, four-wire type power, or R-phase current transformer (CT_R) for any one phase selected from among three phases ), any one of the T-phase current transformer (CT_T) and the S-phase current transformer (CT_S) is connected, and the insulation separation type mechanical latch monitoring and protection device 100 is connected in parallel with the control and measuring unit 200 .
Insulation separation type mechanical latch monitoring and protection device of secondary commercial circuit of current transformer for switchgear, characterized in that delete delete

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