KR101541277B1 - Protection coordination circuit for limiting overcurrent and method thereof - Google Patents

Abstract

Provided are a protection coordination circuit for limiting overcurrent and a method thereof. The protection coordination circuit for limiting overcurrent according to an embodiment of the present invention, in a protection coordination circuit for connecting a power line extended from a power plant with a power line extended from a load in series, and limiting overcurrent which flows along the power lines, includes: a current limitation circuit which includes a semiconductor device and a fuse connected to the semiconductor device in series; and a recloser which is connected to the current limitation circuit in parallel.

Description

TECHNICAL FIELD [0001] The present invention relates to a protection cooperative circuit and method for limiting an overcurrent,

The present invention relates to a protection cooperative circuit and method for limiting an overcurrent, and more particularly, to a protection cooperative circuit and method for limiting an overcurrent when an overcurrent flows due to an accident or a distributed power source, And to a protective cooperative circuit and method for restricting overcurrent that can make the coordination of the protection system in common.

In response to the sharp rise in prices of oil and natural gas, the power industry is expected to have significant and rapid changes in the structure, operation, planning and regulation of the power industry.

1 is a diagram illustrating various causes that can cause a failure of a line in a conventional power transmission system. 2 is an equivalent circuit when a line failure occurs as shown in Fig.

Referring to Fig. 1, a cause of a line fault may be caused by a lightning strike, an equipment failure due to a car accident or the like in contact with a structure such as a tree, contact with an animal, or an accident caused by a construction error.

Referring to FIG. 2, when a line failure occurs due to various causes described in FIG. 1, not only a current supplied to the load 25 but also an overcurrent flowing through 27 in FIG. 2 is generated on the power line. When the overcurrent flows, the recloser is opened and reloaded several times to determine whether it is a temporary failure or a permanent failure.

3 is an equivalent circuit when a plurality of distributed power sources are brought into the power system. 4 to 6 are a circuit diagram and a conceptual diagram for explaining the amount of current flowing in the power system on the assumption that there is one distributed power source (DG).

In Fig. 3, DG1 to DG4 denote distributed power sources such as wind power, solar light, and fuel cells.

As shown in FIG. 4, when there is one distributed power source, the amount of current provided at the source (Grid) terminal and the amount of current supplied from the terminal of the distributed power source (DG) ) And the current from the distributed power source (Current from DG), the total amount of current on the line from the source terminal to the load terminal will appear as the total current in FIG.

The influence of such a distributed power source is another factor that causes a long time overcurrent to flow on the line, in addition to the line failure due to various accident causes described in Figs.

Transients If there is an accident on the power line or there is a distributed power source, a temporary or continuous overcurrent flows through the distribution line. If a transient overcurrent occurs, the recloser recovers the normal line by automatic re-input after opening, and in the event of a permanent failure, the open input is repeated according to the set number of leaps, By separating the line from the line, it maintains stable line condition. Such automatic reclosing is utilized as an economical and effective method for improving the capacity, reliability and stability of the power system.

However, in addition to the reclosing, a fuse can be used for the protection co-operation of the power system. Normally, cooperative co operation means that when the temporary over-current flows, the recloser operates before the fuse, Is meant to prevent the overcurrent on the power system by initially allowing the recloser to operate before the fuse and eventually breaking the fuse.

However, when the overcurrent flows above a certain value due to the characteristics of the recloser and the fuse, the fuse may be blown before the recloser. In this case, the protection cooperation on the power system is broken.

Accordingly, it is possible to prevent the protection cooperative operation of the power system from being broken, and to appropriately control the amount of the overcurrent flowing in the line regardless of the cause of the overcurrent, whether it is various accidents or distributed power, There is a need.

In the past, Smart FCC (Fault Current Controller) technology has been widely used, but superconductivity is used. In order to maintain the superconducting state, various facilities and costs such as a cooling device are included. Also, other prior arts have tried to maintain the protection cooperative system by reducing the current when re-inputting by installing switch and fault current controller in circuit breaker and fuse, but it is necessary to maintain the protection coordination. Thereby increasing the cost.

Korean Laid-Open Patent No. 2013-0128117 (published on November 26, 2013) Korean Registered Patent No. 0959661 (Announced on May 17, 2010) Japanese Laid-Open Patent Application No. 1994-225479 (published on Aug. 12, 1994) Japanese Utility Model Publication No. 1990-88427 (published on July 12, 1990)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a power supply system and a power supply system for preventing overcurrent, which can prevent a power supply system from being broken, Protection cooperating circuit and method.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a protection cooperative circuit for limiting an overcurrent, the protection cooperative circuit comprising: a transmission line extending from a power plant; a transmission line extending from the load; A cooperative circuit comprising: a current limiting circuit comprising a semiconductor element and a fuse in series with the semiconductor element; And a recloser connected in parallel with the current limiting circuit.

In addition, the semiconductor device may include first and second semiconductor devices, and at least one of the first and second semiconductor devices may be a thyristor.

In addition, an anode of the first semiconductor element is connected to a cathode of the second semiconductor element, a cathode of the first semiconductor element is connected to a node of the second semiconductor element, A control signal applied from the outside can be applied to the gate of the first or second semiconductor element.

In addition, when a steady current flows before the overcurrent occurs, the steady current may flow through the recloser.

In addition, when an overcurrent flows in the transmission line, the recloser can perform a shutoff operation.

Further, in the re-closing operation of the recloser, current can flow through the fuse.

The current can be reduced by the semiconductor device.

According to an aspect of the present invention, there is provided a protection cooperative method for limiting an overcurrent, the method comprising: connecting a transmission line extending from a power plant and a transmission line extending from a load in series and protecting the overcurrent flowing in the transmission line A method of coordinating, comprising: supplying a current flowing through a transmission line to a load through a recloser; Blocking the overcurrent by the recloser when an overcurrent flows through the power transmission line; And causing a current to flow through the fuse connected in parallel with the recloser during re-closing operation of the recloser.

The method may further include reducing the amount of current flowing in the first semiconductor device connected in parallel with the recloser and in series with the fuse.

Further, the current may be an alternating current, and the first semiconductor element may be a bidirectional thyristor.

The first semiconductor device may further include a second semiconductor device connected in parallel with the first semiconductor device, wherein the first and second semiconductor devices are thyristors, and an anode of the first semiconductor device is connected to the second semiconductor device Wherein a cathode of the first semiconductor element is connected to a node of the second semiconductor element and a control signal is applied to a gate of the first and second semiconductor elements, have.

And the control signal includes a first control signal applied to a gate of the first semiconductor element and a second control signal applied to a gate of the second semiconductor element, And the frequency of the second control signal are respectively equal to the frequency of the alternating current and the first control signal and the second control signal are alternately applied to the gate of the first semiconductor element and the gate of the second semiconductor element, .

Other specific details of the invention are included in the detailed description and drawings.

According to the embodiments of the present invention, it is possible to appropriately adjust the amount of the overcurrent flowing in the line, to make the power system common protection cooperate well, and to prevent the fuse from being cut off first.

In addition, it is possible to control the fault current of the power system properly without breaking the power system, so that it can operate according to the protection cooperation, The reliability and stability of the power system can be improved by appropriately controlling the overcurrent on the transmission line due to the current supplied from the at least one distributed power source existing in the line as well as the line fault due to the medium accident.

Moreover, the cost can be reduced by constructing a protection cooperation system with only the recloser, the semiconductor device, and the fuse without adding a switch.

1 is a diagram illustrating various causes that can cause a failure of a line in a conventional power transmission system.
Fig. 2 is an equivalent circuit when a line failure occurs as shown in Fig.
3 is an equivalent circuit when a plurality of distributed power sources are brought into the power system.
FIGS. 4 to 6 are a circuit diagram and a conceptual diagram for explaining the amount of current flowing in the power system on the assumption that there is one distributed power source (DG).
7 is a graph for explaining the operation characteristics of the recloser and the fuse used in the power system.
8 is a schematic diagram illustrating a smart grease system to which embodiments of the present invention are applied.
9 is an equivalent circuit of a line when a protection cooperative circuit for limiting an overcurrent according to an embodiment of the present invention is applied to a power system.
FIG. 10 is an equivalent circuit simplifying FIG. 9 as an equivalent circuit of a line when a protection cooperative circuit for limiting an overcurrent according to an embodiment of the present invention is applied to a power system.
11 is a graph showing a state where the recloser operates from a momentary fault to a point at which the cause of the fault is removed.
12 is a graph showing the amount of current flowing through the transmission line when the recloser repeats opening and closing several times.
FIG. 13 is a graph showing the amount of current flowing through a transmission line when simulation is performed for a case where a temporary overcurrent flows according to the embodiment of FIG.
FIG. 14 is a graph showing the amount of current flowing through the transmission line when simulating a case where a continuous overcurrent flows according to the embodiment of FIG. 10; FIG.
15A to 15C are diagrams illustrating the operation of the recloser according to the current flow in the protection cooperative circuit for limiting the overcurrent according to the embodiment of the present invention.
16 is a circuit diagram showing a circuit to which a semiconductor device is connected.
FIGS. 17A and 17B show embodiments in which the waveform of the current is distorted by the semiconductor elements, respectively.
18 is a flowchart of a protection cooperative method for limiting an overcurrent according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Although the first, second, etc. are used to describe various elements, components and / or sections, it is needless to say that these elements, components and / or sections are not limited by these terms. These terms are only used to distinguish one element, element or section from another element, element or section. Therefore, it goes without saying that the first element, the first element or the first section mentioned below may be the second element, the second element or the second section within the technical spirit of the present invention.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprises " and / or "comprising" when used in this specification is taken to specify the presence or absence of one or more other components, steps, operations and / Or additions.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

7 is a graph for explaining the operation characteristics of the recloser and the fuse used in the power system.

Referring to Fig. 7, the curve S indicates the operating characteristics of the fuse, and the curve R indicates the operating characteristics of the recloser. The X-axis of the graph represents the amount of current and the Y-axis represents the time at which the current flows. Here, R1 is the normal operation of the recloser, and R2 is the recloser operation when it breaks the fuse. As the current increases, the fuse graph S1 falls below the graph R1 of the recloser and the fuse blows first.

More specifically, when the amount of current flowing in the transmission line is smaller than a predetermined value, that is, in the range of T, it is a recloser to react first assuming that a constant amount of current overcurrent flows continuously. That is, before the fuse reacts and breaks, the recloser first reacts to limit the flow of current (see curve R1). However, when the amount of current flowing in the transmission line is larger than a predetermined value, that is, in the range of U, the fuse first reacts more than the recloser and is cut off (see curve S1).

In this case, referring again to FIG. 3, if an overcurrent occurs due to an accident occurring in a transmission line (Line M) directed to the main load among the equivalent circuits denoted by N, , The fuse 9 reacts first and is opened rather than the recloser CB2. This will also cause problems with the current transmission to the transmission line (Line C) towards the critical load, which is not directly related to the point where the accident occurred. In order to prevent such a situation, it is necessary to make the recloser CB2 react before the fuse 9. To do so, it is necessary to control so that the amount of current flowing in the transmission line does not belong to the U region.

8 is a schematic diagram illustrating a smart grease system to which embodiments of the present invention are applied.

Recently, a Smart Grid has been introduced to optimize energy efficiency through the exchange of power usage information in a bi-directional real-time manner by a power supplier or a system operator and a consumer through a combination of a power grid and a communication network. In the Smart Grid, independent operation is carried out with the introduction of distributed power sources centered on new and renewable energy. In order to respond to the needs of consumers in real time, intelligent and other technologies based services are provided, Which overcomes the inefficiency of the system.

Referring to FIG. 8, in the smart grid system, it is possible to receive and manage information about the voltage, current, and the like in the power system through communication. Based on such information, the equivalent circuit of the line side can be calculated. The magnitude of the current can be controlled at an appropriate level so that the protection cooperates.

9 is an equivalent circuit of a line when a protection cooperative circuit for limiting an overcurrent according to an embodiment of the present invention is applied to a power system. Fig. 10 is an equivalent circuit simplifying Fig. 9 as an equivalent circuit of a line when a protection cooperative circuit for limiting an overcurrent according to an embodiment of the present invention is applied to a power system.

Referring to FIG. 9, if an equivalent circuit for a line calculated and derived in the smart grid system is as shown in FIG. 9, if a protection cooperative circuit 50 for limiting an overcurrent according to an embodiment of the present invention is applied , The magnitude of the current can be controlled to an appropriate level when an overcurrent due to a cause such as line failure of the system or current supply from the distributed power supply occurs.

10, a protection cooperating circuit 50 for limiting an overcurrent according to an embodiment of the present invention may include a recloser 53, a first semiconductor element 55, and a fuse 59 . Further, the protection cooperating circuit 50 for limiting the overcurrent may further include the second semiconductor element 57. [

One end of the protection cooperating circuit 50 for limiting the overcurrent according to the embodiment of the present invention is connected to the power transmission line extending from the power plant 21 and the other end is connected in series with the power transmission line extending from the load 25 So that the protection cooperative circuit controls an overcurrent that flows between the power plant 21 and the load 25 when an accident 27 occurs or flows from one or more distributed power sources. In detail, the protection cooperating circuit 50 for limiting the overcurrent according to an embodiment of the present invention includes a current limiting circuit including a semiconductor element 55 and a fuse 59 connected in series with the semiconductor element 55, And a recloser 53 connected in parallel with the current limiting circuit.

The recloser 53 is connected in series with a current limiting circuit comprising a semiconductor element 55 and a fuse 59 in series with the semiconductor element 55. That is, one end of the recloser 53 is connected to the power transmission line extending from the power plant 21, and the other end is connected to the power transmission line extending from the load 25, respectively.

The recloser, which is one component of the protection cooperating circuit 50 for limiting the overcurrent according to the embodiments of the present invention, can use a recloser which has been used in the past. As described above, the conventional recloser has a relatively simple constitutional component installed therein. In particular, since the switch is not used, there is a considerable advantage in terms of installation cost.

The role of the recloser will be described with reference to FIGS. 11 and 12. FIG.

11 is a graph showing a state where the recloser operates from a momentary fault to a point at which the cause of the fault is removed. 12 is a graph showing the amount of current flowing through the transmission line when the recloser repeats opening and closing several times.

The time point A in Figs. 11 and 12 is a time point at which a failure occurs. As shown in Fig. 12, an overcurrent flows through the power line. At this time, the recloser opens the power line at time point B to interrupt the current flow. Then, C and D are the time points at which the reclosing and re-closing are performed, and E and F are the same. Assuming that the cause of the failure has been removed at time G as a temporary failure, the power transmission system will operate correctly again at time H when the recloser again performs the re-input.

In Fig. 12, the state of the current flowing through the transmission line when the re-charging is performed twice can be seen. However, as shown in FIG. 12, excessive current flows through the power line even after the power is re-applied, which may negatively affect the life of many devices installed in the power system as well as unnecessary power loss. have.

Furthermore, if the cause of the fault is not removed at the G point, or if a continuous overcurrent flows, such as when current flows from more than one distributed power source, the fuse must be activated and disconnected to open the wires as described previously for protection co-operation. However, when the amount of the overcurrent is very large, as described above with reference to FIG. 7, the fuse first reacts more than the recloser, which causes a problem.

Therefore, it is necessary to prevent the operation error of the protection cooperative system by controlling the amount of such over current that occurs after the re-closing time of the recloser.

Hereinafter, the process of controlling the amount of the overcurrent will be described in detail.

FIG. 13 is a graph showing the amount of current flowing through a transmission line when simulation is performed for a case where a temporary overcurrent flows according to the embodiment of FIG. FIG. 14 is a graph showing the amount of current flowing through the transmission line when simulating a case where a continuous overcurrent flows according to the embodiment of FIG. 10. FIG. 15A to 15C are diagrams illustrating the operation of the recloser according to the current flow in the protection cooperative circuit for limiting the overcurrent according to the embodiment of the present invention.

Referring again to FIG. 10, the first semiconductor element 55 is connected in parallel with the recloser 53, with a fuse 59 connected in series with the first semiconductor element 55. In addition, the first semiconductor element 55 may further include a second semiconductor element 57 connected in parallel.

Accordingly, when the normal current flows, the current flows through the recloser 53. When the recloser 53 is operated and opened in the event of an accident, the current flows through the first and / or second semiconductor elements 55 and 57, Lt; / RTI > Referring to FIG. 15A, in a steady state, a current is bypassed to the recloser 53, so that a steady current flows through the recloser 53. Also, referring to FIG. 15B, when an overcurrent flows in the transmission line, the recloser performs a shutoff operation. At this time, the recloser 53 performs a reclosing operation every few seconds to confirm that it is a temporary failure, and when the failure of the line is restored, the recloser 53 is also closed and the recloser 53 is closed A steady current flows. Referring to FIG. 15C, when the recloser 53 is open and the recloser 53 is re-charged, current flows toward the fuse and the semiconductor device 55 ) To reduce the current.

Here, the first and second semiconductor elements 55 and 57 may be a thyristor. A thyristor is a three-terminal semiconductor device which conducts a gate current from a gate to a cathode, and is capable of conducting between an anode and a cathode, and is also referred to as a SCR (Silicon Controlled Rectifier). All voltages in the power system are AC (alternating current), and 220V is the root mean square (RMS), which is equal to 220V DC. , The first and second semiconductor elements 55 and 57 can be used to change the supply voltage by distorting this waveform.

Only the first semiconductor element 55 may be used but an anode of the first semiconductor element 55 may be connected to the second semiconductor element 57 when the second semiconductor element 57 is used together with the first semiconductor element. 57), and the cathode of the first semiconductor element (55) is connected in parallel with the structure connected to the node of the second semiconductor element (57), so that the current flowing in the transmission line The current flowing in both directions can be controlled. Alternatively, when only the first semiconductor element 55 is used, the first semiconductor element 55 may be a bidirectional thyristor, in which case the parallel structure of the first and second semiconductor elements 55, It plays a similar role.

16 is a circuit diagram showing a circuit to which a semiconductor device is connected. 17A and 17B show embodiments in which the current waveform is distorted by the semiconductor elements, respectively.

10 and 16, in the protection cooperating circuit 50 for limiting the overcurrent according to the embodiments of the present invention, the control signals of a predetermined period are applied to the gates 56 and 58 of the first and / To limit the flow of the overcurrent.

The control signal of a constant period means that, for example, assuming that the current flowing in the transmission line has a frequency of 60 Hz as an alternating current and only the first semiconductor element 55 is used, the control signal also has a period of 1/60 second, The current waveform flowing through the first semiconductor element 55 in this case may be as shown in Fig. 17A. At this time, the time (?) For applying the control signal within one cycle may be changed as needed, and thus a current as much as necessary may be supplied to the lower stage during the re-closing period of the recloser 53 .

Assuming that the current flowing in the transmission line has a frequency of 60 Hz as an alternating current and the first and second semiconductor elements 55 and 57 are used together, two control signals having a period of 1/60 second are alternately May be alternately applied to the two gates (56, 58). In this case, the waveform of the current flowing through the first and second semiconductor elements 55 and 57 may be as shown in FIG. 17B. At this time, a time point (?) For applying a control signal to the gate 56 of the first semiconductor element 55 and a point (?) For applying a control signal to the gate 58 of the second semiconductor element 57 So that it is possible to provide a current of a required level during the re-closing period of the recloser 53 to the lower stage.

Assuming that the current flowing in the transmission line has a frequency of 60 Hz as an alternating current and only the first semiconductor element 55 is used and the first semiconductor element 55 is a bidirectional thyristor, And the current waveform flowing through the first semiconductor element 55 in this case may be similar to that of FIG. 17B. At this time, the time points (alpha and beta) for applying the control signal within the half period may be changed as needed, so that a current of a necessary degree is supplied to the subordinate stage during the re-closing period of the recloser 53 .

As a result of controlling the amount of current as described above, when the transient overcurrent flows, that is, when the overcurrent flows for a predetermined period (t1 in FIG. 13), the amount of current is reduced as shown in FIG. In addition, when the continuous overcurrent flows, that is, when the overcurrent flows for a predetermined period (t1 in FIG. 14), the amount of current after the reclosing time point C is reduced do.

As the amount of the overcurrent is reduced, the possibility that the fuse reacts before the recloser, that is, the amount of the overcurrent in FIG. 7 falls within the range of U, can be reduced as much as possible.

In this case, it is possible to control the overcurrent to flow for a period of t2 with a controlled amount (J in Fig. 14) to some appropriate level. In this case, the controlled current amount J is controlled so as to be the amount of the current belonging to the range of T in FIG. 7, and the period t2 is controlled to the period until the fuse reacts to the overcurrent flowing by the amount of J and is broken.

If it is determined that a temporary overcurrent flows, the re-closing operation is not performed after the shut-off operation of the recloser 53 is performed, thereby eliminating the temporary problem occurring in the system without requiring the operation of the fuse . When it is judged that the continuous overcurrent flows, the thyristor is operated only when the recloser 53 is re-charged, and the current flows to the fuse 59 side. At this time, the current is reduced at first to help the recloser 53 to operate before the fuse 59, but when the fuse 59 is to be cut off, the current is slightly increased and the fuse 59 is cut off.

18 is a flowchart of a protection cooperative method for limiting an overcurrent according to an embodiment of the present invention.

Referring to FIG. 18, a protection cooperative method for limiting an overcurrent according to an embodiment of the present invention includes connecting a transmission line extending from a power plant and a transmission line extending from a load, and limiting an overcurrent flowing in the transmission line (S130). When an overcurrent flows in the transmission line (S120, Y), the overcurrent is cut off by the recloser (S130), and the overcurrent is cut off by the recloser , The re-closing operation of the recloser is performed (S140). Here, the amount of current flowing through the first semiconductor element connected in parallel with the recloser is reduced (S150). If it is a temporary failure (S160, Y) after the reclosing operation of the recloser, the shutoff operation of the recloser is repeated to solve the failure (S170). After the re-closing operation, if a continuous failure (S160, N) is not a temporary failure but a current is caused to flow through the fuse connected in parallel with the reclosing unit (S180), the fuse is disconnected (S190) Thereby protecting the power system.

At this time, the current is an alternating current, and the first semiconductor element may be a bidirectional thyristor, and the description thereof is the same as the protective cooperative circuit for limiting the above-mentioned overcurrent, and a detailed description will be omitted.

The first semiconductor device may further include a second semiconductor device connected in parallel with the first semiconductor device, wherein the first and second semiconductor devices are thyristors, and an anode of the first semiconductor device is connected to the second semiconductor Wherein a cathode of the first semiconductor element is connected to a node of the second semiconductor element and a control signal is applied to a gate of the first and second semiconductor elements, And the explanation thereof is the same as the protection cooperative circuit for limiting the above-mentioned overcurrent, so that detailed description will be omitted.

Wherein the control signal includes a first control signal applied to a gate of the first semiconductor element and a second control signal applied to a gate of the second semiconductor element, And the second control signal may be alternately applied to the gates of the first semiconductor element and the second semiconductor element, respectively, and the first control signal and the second control signal may be alternately applied to the gate of the first semiconductor element and the gate of the second semiconductor element, Since the description is the same as the above-mentioned protection cooperative circuit for limiting the overcurrent, detailed description will be omitted.

The fault current due to various accidents or various dispersed electric power sources such as wind or sunlight is greatly increased in the actual system through the protection cooperative circuit and the protection cooperative method which limit the overcurrent according to various embodiments of the present invention. In order to prevent the malfunction by flowing current only to the closing mechanism, the current can be reduced by the semiconductor device, for example thyristor, and the current can flow only through the fuse.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

50: Protection cooperating circuit
53: Recloser
55, 57: first semiconductor element
56, 58: gate of the first and second semiconductor elements
59: Fuse

Claims (12)

A protection cooperative circuit for connecting a transmission line extending from a power plant and a transmission line extending from a load in series and restricting an overcurrent flowing in the transmission line,
A current limiting circuit including a semiconductor element and a fuse connected in series with the semiconductor element; And
And a recloser connected in parallel to the current limiting circuit and designed to repeatedly open and re-enter when the over current is sensed and to send the over current to the current limiting circuit when the over current is maintained for a predetermined time or longer A protective cooperative circuit that limits overcurrent. The method according to claim 1,
Wherein the semiconductor element includes first and second semiconductor elements,
Wherein at least one of the first and second semiconductor elements is a thyristor. 3. The method of claim 2,
Wherein an anode of the first semiconductor element is connected to a cathode of the second semiconductor element and a cathode of the first semiconductor element is connected to a node of the second semiconductor element, Wherein the control signal applied to the gate of the first or second semiconductor element is limited. The method according to claim 1,
Wherein when the steady current flows before the overcurrent flows, the steady current limits the overcurrent flowing through the recloser. The method according to claim 1,
And the overcurrent is restricted when the overcurrent flows to the power line. 6. The method of claim 5,
Wherein the current is supplied to the fuse when the recloser is in the re-charging operation. The method according to claim 6,
A protection cooperating circuit for limiting the current to the semiconductor element and limiting the overcurrent. CLAIMS 1. A protection cooperation method for connecting a transmission line extending from a power plant and a transmission line extending from a load in series and restricting an overcurrent flowing in the transmission line,
Supplying a current flowing through the power transmission line to the load through a recloser;
Blocking the overcurrent by the recloser when an overcurrent flows through the power transmission line;
Determining whether the overcurrent is a transient overcurrent by the recloser when the recloser is re-charged;
And causing a current to flow through a fuse connected in parallel with the recloser when re-closing the re-closure when the over-current is not a temporary over-current. 9. The method of claim 8,
Further comprising reducing the amount of current flowing in the first semiconductor component connected in parallel with the recloser and in series with the fuse. 10. The method of claim 9,
The current is an alternating current,
Wherein the first semiconductor element is a bi-directional thyristor. 10. The method of claim 9,
And a second semiconductor element connected in parallel with the first semiconductor element,
Wherein the first and second semiconductor elements are thyristors,
Wherein an anode of the first semiconductor element is connected to a cathode of the second semiconductor element and a cathode of the first semiconductor element is connected to a node of the second semiconductor element, 1 and the gate of the second semiconductor element is applied with a control signal. 12. The method of claim 11,
The current is an alternating current,
Wherein the control signal includes a first control signal applied to a gate of the first semiconductor element and a second control signal applied to a gate of the second semiconductor element,
Wherein a frequency of the first control signal and a frequency of the second control signal are respectively equal to a frequency of the alternating current and the first control signal and the second control signal are alternately applied to the gate of the first semiconductor element and the gate of the second semiconductor element, A method of cooperative protection that limits the overcurrent applied to the gate.

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