Busbar protection devices, power receiving equipment and busbar protection methods

Abstract

To eliminate the influence of a blind spot section to remove an accident even when a converter is arranged on a secondary side of a circuit breaker to reduce an installation space.SOLUTION: A bus protection device of an embodiment is used in a power receiving installation having a plurality of individual buses constituting parallel multiple lines, a common bus commonly connectable to the plurality of individual buses, a common converter provided on a side of the common bus of a common circuit breaker provided at a connection point of the common bus and the plurality of individual buses, a plurality of converters provided respectively on a side of the individual buses of the common circuit breaker, and a plurality of individual circuit breakers provided on the respective individual buses and cutting off the corresponding individual buses in a cut-off state of the common circuit breaker. When a bus accident in the common bus is detected by a bus accident detection unit based on output from the common converter, a first accident dealing unit cuts off the common circuit breaker, and when a bus accident in the corresponding individual bus is detected based on output from any one of the plurality of converters after the cut-off of the common circuit breaker, a second accident dealing unit cuts off the corresponding individual circuit breaker.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Embodiments of the present invention relate to a busbar protection device, power receiving equipment, and a busbar protection method. [Background Art]

[0002] Conventionally, in power receiving equipment with two parallel lines (system A and system B), there are cases where a circuit of power receiving equipment that allows a common busbar to be connected to an A-system busbar and a B-system busbar is constructed. In the above configuration, during normal operation, power is distributed to each load via the A-system busbar and the B-system busbar. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2009-05731 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] On the other hand, during transmission line inspection, in order to maintain two parallel lines, the common busbar is used, and operation is performed while maintaining two parallel line power reception. Conventionally, current transformers have been arranged on the primary side and secondary side of circuit breakers to separately detect busbar faults on the common busbar and the A-system busbar, and busbar faults on the B-system busbar.

[0005] For this reason, there has been a risk that the installation space for arranging current transformers (CT) becomes large.

[0006] In order to reduce the installation space for arranging current transformers (CT), it is conceivable to arrange the current transformers on the secondary side of the circuit breaker. However, a blind section for busbar faults occurs between the circuit breaker and the current transformer. If a busbar fault such as a ground fault occurs in this blind section, the busbar fault will continue even after the circuit breaker is tripped, and there is a risk that the fault cannot be removed by the busbar protection relay.

[0007] The present invention has been made in view of the above, and aims to provide a busbar protection device, power receiving equipment, and busbar protection method that eliminate the influence of blind spots and enable fault removal by a busbar protection relay, even when the current transformer is placed on the secondary side of the circuit breaker in order to reduce installation space. [Means for solving the problem]

[0008] The busbar protection device of the embodiment provides busbar protection for a power receiving facility having a plurality of individual busbars constituting a plurality of parallel lines, a common busbar that can be commonly connected to the plurality of individual busbars, a common current transformer provided on the common busbar side of a common circuit breaker provided at the connection point between the common busbar and the plurality of individual busbars, a plurality of current transformers provided on the individual busbar side of the common circuit breaker, and a plurality of individual circuit breakers provided on each of the individual busbars when the common circuit breaker is tripped, which trip the corresponding individual busbar. The busbar protection device provides busbar protection for a power receiving facility having a plurality of individual busbars constituting a plurality of parallel lines, a common current transformer provided on the common busbar side of a common circuit breaker provided on the individual busbar side of the common circuit breaker provided on the individual busbar side of the common circuit breaker, and a second fault response unit that trips the corresponding individual circuit breaker when a busbar fault of the common busbar is detected on the common busbar based on the output of the common current transformer in the busbar fault detection unit, and a second fault response unit that trips the corresponding individual circuit breaker when a busbar fault of the corresponding individual busbar is detected on the corresponding individual busbar based on the output of any of the plurality of current transformers after the common circuit breaker has tripped. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram illustrating the power receiving equipment of an embodiment. [Figure 2] Figure 2 is a functional block diagram of the busbar protection relay according to the embodiment. [Figure 3] Figure 3 is a diagram illustrating the normal operation. [Figure 4] Figure 4 shows the flowchart of the process during power line inspection. [Figure 5] Figure 5 is an explanatory diagram of how fault detection on the common busbar is performed during power transmission line inspection. [Figure 6] Figure 6 is an explanatory diagram of how to detect accidents in blind spots during power line inspections. [Figure 7] Figure 7 is an explanatory diagram of fault response when the fault current detection point (fault point) is on the busbar BA. [Figure 8] Figure 8 is an explanatory diagram of the power supply resumption process. [Modes for carrying out the invention]

[0010] Figure 1 is a schematic diagram illustrating the power receiving equipment of an embodiment. In the following description, the power receiving equipment 10 is assumed to be equipped with a common busbar BC, and individual busbars BA and BB.

[0011] As shown in Figure 1, the power receiving equipment 10 receives power from distribution lines LA, LB, and LC. Distribution line LA is connected to busbar BA via disconnector DS, (current transformer CTA1-3), circuit breaker CBA1-3, and two disconnectors DS. Furthermore, busbar BA is connected to common busbar BC via disconnector DS, (current transformer CTC1), (current transformer CTA4), and circuit breaker CBAC.

[0012] A load (not shown) is connected to the busbar BA via a disconnector DS and a circuit breaker CBA1. A current transformer CTA1 is provided that detects the current flowing from the circuit breaker CBA1 to the load (not shown) and outputs an output signal A1.

[0013] Similarly, other loads (not shown) are connected via disconnector DS and circuit breaker CBA2, and a current transformer CTA2 is provided that detects the current flowing from circuit breaker CBA2 to the other loads (not shown) and outputs an output signal A2.

[0014] Furthermore, other loads (not shown) are connected via disconnector DS and circuit breaker CBA3, and a current transformer CTA3 is provided that detects the current flowing from circuit breaker CBA3 to the other loads (not shown) and outputs an output signal A3.

[0015] A bus bar BB is connected to the distribution line LB via a disconnector DS, (current transformers CTB1 to CTB3), circuit breakers CBA1 to CBA3, and two disconnectors DS. Further, the bus bar BB is connected to a common bus bar BC via a disconnector DS, (current transformer CTC2), (current transformer CTB4), and a circuit breaker CBBC. A load (not shown) is connected to the bus bar BB via a disconnector DS and a circuit breaker CBB1, and a current transformer CTB1 that detects a current flowing from the circuit breaker CBB1 to the unshown load and outputs an output signal B1 is provided.

[0016] Similarly, another unshown load is connected via a disconnector DS and a circuit breaker CBB2, and a current transformer CTB2 that detects a current flowing from the circuit breaker CBB2 to the other unshown load and outputs an output signal B2 is provided.

[0017] Further, yet another unshown load is connected via a disconnector DS and a circuit breaker CBB3, and a current transformer CTB3 that detects a current flowing from the circuit breaker CBB3 to the yet another unshown load and outputs an output signal B3 is provided.

[0018] Further, the bus bar BA and the bus bar BB can be connected via a pair of disconnectors DS and a circuit breaker CBAB. In this case, between one disconnector DS provided on the bus bar BA side and the circuit breaker CBAB among the pair of disconnectors DS, a current transformer CTA-B that detects a current flowing between the bus bar BA and the bus bar BB and outputs a detection signal is provided.

[0019] Similarly, between the other disconnector DS provided on the bus bar BB side and the circuit breaker CBAB among the pair of disconnectors DS, a current transformer CTB-A that detects a current flowing between the bus bar BA and the bus bar BB and outputs a detection signal is provided.

[0020] A common bus bar BC is connected to the distribution line LC via a disconnector DS, (current transformer CTCC), a circuit breaker CBCC, and a disconnector DS. Furthermore, between the common busbar BC and busbar BA, disconnectors DS, circuit breakers CBAC, (current transformer CTA4), (current transformer CTC1), and disconnector DS are provided, moving from the common busbar BC toward busbar BA.

[0021] Furthermore, between the common busbar BC and busbar BB, from the common busbar BC toward busbar BB, there are disconnectors DS, circuit breakers CBBC, (current transformers CTB4), (current transformers CTC2 ) and a disconnector DS are provided.

[0022] In the above configuration, the output signals A1 of current transformer CTA1, A2 of current transformer CTA2, A3 of current transformer CTA3, A4 of current transformer CTA4, the output signals of current transformers CTA1-3, and the output signal of current transformer CTB-A are output to the busbar protection relay RLA, which detects a fault in the busbar BA system and shuts off busbar BA. When the busbar protection relay RLA detects a fault in the busbar BA system, it shuts off circuit breakers CBA1-3 and CBAB.

[0023] Furthermore, the output signals B1 of current transformer CTB1, B2 of current transformer CTB2, B3 of current transformer CTB3, B4 of current transformer CTB4, the output signals of current transformers CTB1-3, and the output signal of current transformer CTA-B are output to the busbar protection relay RLB, which detects a fault in the busbar BB system and shuts off the busbar BB. When the busbar protection relay RLB detects a fault in the busbar BB system, it shuts off circuit breakers CBB1-3 and CBAB.

[0024] Furthermore, the output signals C1 from current transformer CTC1, C2 from current transformer CTC2, and CTCC from current transformer CTCC are output to busbar protection relay RLC, which detects a fault on the common busbar BC and shuts off the common busbar BC. If busbar protection relay RLC detects a fault on the common busbar BC, it puts circuit breaker CBCC into the tripped state.

[0025] Furthermore, if a fault is still detected in the busbar BA system while the circuit breaker CBCC is tripped, the busbar BA system will be controlled to trip, assuming that a fault exists in the blind spot section of the busbar BA system.

[0026] Furthermore, after the busbar BA system is shut off, if no fault is detected in the busbar BB system, the busbar protection relay RLC will open the circuit breaker CBCC to supply power from the common busbar BC to the busbar BB system.

[0027] Similarly, if a fault is still detected in the busbar BB system while the circuit breaker CBCC is tripped, the busbar BB relay RLC will control the system to trip, assuming that a fault exists in the blind spot section of the busbar BB system.

[0028] Furthermore, after the busbar BB system is shut off, if no fault is detected in the busbar BA system, the busbar protection relay RLC will open the circuit breaker CBCC to supply power from the common busbar BC to the busbar BA system.

[0029] Figure 2 is a functional block diagram of the busbar protection relay according to the embodiment. The busbar protection relay RLC comprises an input conversion unit F1, a fault detection unit F2, and a DO unit unit F3. The input conversion unit F1 converts the input current signal and outputs the converted signal to the fault detection unit F2.

[0030] The fault detection unit F2 functions as a bus fault detection unit, detecting current changes on the common bus BC based on the conversion signal from the input conversion unit F1, detecting a fault on the common bus BC, and notifying the DO unit F3.

[0031] The DO unit F3 functions as the first fault response unit. When a fault on the common bus BC is detected and notified by the fault detection unit F2 using the first route RT1, it sets all circuit breakers on the common bus BC to the tripped state (open state).

[0032] When all circuit breakers on the common bus BC are in the tripped state, the input conversion unit F1 converts the input current signal and outputs the converted signal to the fault detection unit F2. The fault detection unit F2 functions as a bus fault detection unit, detecting current changes on the common bus BC based on the conversion signal from the input conversion unit F1, detecting a fault on the common bus BC, and notifying the DO unit F3.

[0033] As a result, when all circuit breakers on the common bus BC are in the tripped state and the fault detection unit F2 detects a fault on the common bus BC using the second path RT2, the DO unit F3 determines that a fault has been detected in the blind spot section and determines whether the fault was detected on bus BA or on bus BB.

[0034] The DO unit F3 then functions as a second fault response unit, and if it determines that the fault has been detected on either busbar BA or busbar BB, it trips all circuit breakers on the busbar on the side where the fault was detected. This completely shuts off the fault current, including in blind spots.

[0035] Therefore, the DO unit F3 functions as a reset unit and, using the third path RT3, resets all circuit breakers on the common bus BC connected to the bus on the side where no fault was detected using the second path RT2, thereby restoring conduction and resetting the bus on the side where no fault was detected.

[0036] As described above, according to this embodiment, in order to reduce the installation space, the current transformer (in the case of Figure 1, current transformer CTC1, current transformer CTA4 , current transformer CTC2 and current transformer CTB4 Even if the ) is positioned on the secondary side of the circuit breaker, the influence of the blind spot section can be eliminated and fault removal can be performed by the busbar protection relay.

[0037] The operation of the embodiment will be described in more detail below. [1] Normal operation First, let's explain the operation under normal circumstances (when no abnormalities are detected). Figure 3 is a diagram illustrating the normal operation. In Figure 3, the hatched circuit breakers are assumed to be in the open state, and the hatched disconnectors are assumed to be in the off state (open state) (the same applies in the following explanation).

[0038] As a result, power from distribution line LA is supplied to the loads of busbar BA and busbar BB via disconnector DS, circuit breakers CBA1-3, and multiple disconnectors DS and circuit breakers CBAB.

[0039] In parallel with the power supply from distribution line LA, power from distribution line LB is supplied to the loads of busbar BA and busbar BB via disconnector DS, circuit breakers CBB1-3, and multiple disconnectors DS and circuit breakers CBAB.

[0040] [2] Operation during power line inspection Figure 4 shows the flowchart of the process during power line inspection. Figure 5 is an explanatory diagram of how fault detection on the common busbar is performed during power transmission line inspection.

[0041] During power line inspection, the busbar protection relay RLC first switches the power transmission path (step S11).

[0042] For example, in the example shown in Figure 5, since the transmission line inspection is performed using the common busbar BC and the busbar BB of the B system, the two disconnectors DS and circuit breakers CBA1-3, shown by cross-hatching in Figure 5, are left open, and the transmission path is switched from the state of the transmission path shown in Figure 3 to a state where the common busbar BC and busbar BB are connected in order to perform the inspection.

[0043] In Figure 5, the thick lines indicate the current flow path. Furthermore, assume that a ground fault or similar accident has occurred at position PS, indicated by the black star in Figure 5.

[0044] Next, the busbar protection relay RLC determines whether or not it has detected a fault such as a ground fault or short circuit on the common busbar BC based on the output signals of the current transformers CTCC, CTC1, and CTC2 (step S12).

[0045] If a fault is detected on the common bus in step S12 (step S12; Yes), all circuit breakers and disconnectors on the common bus BC are opened (step S13).

[0046] Figure 6 is an explanatory diagram of how to detect accidents in blind spots during power line inspections. In this embodiment, in order to reduce the installation space for current transformers, current transformers CTC1 and CTA4 are placed on the busbar BA side of circuit breaker CBAC, and current transformers CTC2 and CTB4 are placed on the busbar BB side of circuit breaker CBBC.

[0047] In other words, unlike conventional configurations, the current transformer CTC1 and CTA4 are not configured to have one on the common bus BC side, which is upstream of the circuit breaker CBAC, and the other on the bus BA side, which is downstream of the circuit breaker CBAC. Similarly, the current transformer CTC2 and CTB4 are not configured to have one on the common bus BC side, which is upstream of the circuit breaker CBBC, and the other on the bus BB side, which is downstream of the circuit breaker CBBC.

[0048] Therefore, the busbar BA side of circuit breaker CBAC and the busbar BB side of circuit breaker CBBC are blind spots in fault detection on the common busbar, meaning that, for example, a fault at position PS cannot be detected.

[0049] Therefore, the busbar protection relay RLC functions as the first fault response unit, and in Figure 6, it opens the circuit breakers CBCC, CBAC, CBBC, CBAB, CBA1-CBA3, CBB1-3, and the two disconnectors DS flanking CBB1-3, which are indicated by cross-hatching. In other words, it opens the circuit breakers and disconnectors on the common busbar (step S13).

[0050] Then, the busbar protection relay RLC determines whether or not a fault current has been detected only on the busbar BA side, that is, whether or not a fault current has been detected in the blind spot section (step S14).

[0051] In the determination in step S14, if a fault current is still detected only on the busbar BA side, that is, if a fault current is detected in a blind spot section (step S14; Yes), the busbar protection relay RLC determines whether the fault current detection point (fault point) is on busbar BA or busbar BB (step S15).

[0052] Figure 7 is an explanatory diagram of fault response when the fault current detection point (fault point) is on the busbar BA.

[0053] In the case of Figure 7, since fault current is detected by current transformers CTC1 and CTA4, the fault current detection point (fault point) is determined to be on the busbar BA (step S15; BA). Therefore, the busbar protection relay RLC functions as the second fault response unit and, from the state shown in Figure 7, further opens circuit breakers CBA1-3, thereby opening the circuit breakers and disconnectors on the busbar BA (step S16).

[0054] Figure 8 is an explanatory diagram of the power supply resumption process. Next, the busbar protection relay RLC, since the fault current detection point (fault point) is on busbar BA and not on busbar BB, functions as a resetting unit, restarting power supply using the common busbar BC and busbar BB, restoring power supply (step S17), and ending the inspection.

[0055] More specifically, the busbar protection relay RLC, in Figure 8, electrically connects the common busbar BC and busbar BB by setting circuit breakers CBCC and CBBC on the common busbar BC side (shown in gray) to a conductive state, and then resumes power supply to the load on the busbar BB side (not shown) via circuit breakers CBB1 to CBB3, thereby completing the inspection after the fault has been cleared.

[0056] On the other hand, if fault current is detected in current transformers CTC2 and CTB4 during the determination in step S15, the fault current detection point (fault point) is determined to be on the busbar BB (step S15; BB). Therefore, the busbar protection relay RLC functions as a second fault detection unit and, from the state shown in Figure 6, further opens circuit breakers CBB1-3, thereby opening the circuit breakers and disconnectors on the busbar BB (step S18).

[0057] Next, the busbar protection relay RLC, since the fault current detection point (fault point) is on busbar BB and not on busbar BA, functions as a resetting unit, restarting power supply using the common busbar BC and busbar BA, restoring power supply (step S19), and ending the inspection.

[0058] More specifically, the busbar protection relay RLC electrically connects the common busbar BC and busbar BA by making circuit breakers CBCC and CBAC on the common busbar BC side conductive, and then resumes power supply to the load on the busbar BA side (not shown) via circuit breakers CBA1 to CBA3, thereby completing the inspection after the fault has been cleared.

[0059] Furthermore, in the determination in step S14, if no fault current is detected, that is, if a fault current is detected only on the common bus BC (step S14; No), the common bus BC is electrically disconnected, and power supply is continued in the normal power supply state shown in Figure 3, that is, the power supply state by buses BA and BB, and the inspection is completed.

[0060] Furthermore, if no fault is detected on the common bus in the determination in step S12 (step S12; No), it means that a fault current was detected on either bus BA or bus BB. In this case, the bus protection relay RLC opens the circuit breaker and disconnector on the bus where the fault (fault current) was detected (step S21) to clear the fault. Furthermore, the busbar protection relay RLC continues to supply power (step S22) using the busbar BA and busbar BB from which no fault (fault current) was detected, as well as the common busbar BC, and completes the inspection.

[0061] As described above, according to this embodiment, in order to reduce the installation space, the current transformer (in the case of Figure 1, current transformer CTC1, current transformer CTA4 , current transformer CTC2 and current transformer CTB4 Even if the ) is positioned on the secondary side of the circuit breaker, the influence of the blind spot section can be eliminated and fault removal can be performed by the busbar protection relay.

[0062] Here, we will explain why the installation space can be reduced by changing the installation location of the current transformer from the conventional method and installing the circuit breaker used at the connection point between the common bus BC and bus BA or bus BB (in the example in Figure 1, circuit breaker CBAC or circuit breaker CBBC) on the bus BA side or bus BB side.

[0063] In the example shown in Figure 1, GCB (gas circuit breaker) is used as both the CBAC and CBBC circuit breakers.

[0064] Incidentally, conventionally, current transformers (in the example in Figure 1, current transformers CTC1 and CTA4, or current transformers CTC2 and CTB4, and current detection) are placed on the upstream (primary) and downstream (secondary) sides of the GCB (gas circuit breaker), which requires extending copper pipes for the installation of the current transformers. As a result, a large installation space was required.

[0065] In contrast, as in the embodiment, when current transformers are arranged together only on the downstream side (secondary side) of the GCB (gas circuit breaker), they can be placed, for example, above the installation area of ​​the disconnector or grounding switch that needs to be installed on the downstream side (secondary side) of the GCB. As a result, the copper pipes for installation can be shortened as in the conventional method, and the installation space can be reduced compared to when current transformers are installed on both the upstream side (primary side) and the downstream side (secondary side) of the GCB.

[0066] The busbar protection device of this embodiment includes a control device such as a CPU, a storage device such as ROM (Read Only Memory) or RAM, a display device such as a display unit, and an input device such as operation buttons, and has a hardware configuration that utilizes a normal computer.

[0067] The program executed by the busbar protection device of this embodiment is provided as an installable or executable file recorded on a computer-readable recording medium such as a USB memory stick, an SSD (Solid State Drive), or a DVD (Digital Versatile Disk).

[0068] Furthermore, the program executed by the busbar protection device of this embodiment may be stored on a computer connected to a network such as the Internet and provided by downloading it via the network. Alternatively, the program executed by the busbar protection device of this embodiment may be provided or distributed via a network such as the Internet.

[0069] Furthermore, the program for the busbar protection device of this embodiment may be provided pre-installed in a ROM or the like.

[0070] The program executed by the busbar protection device of this embodiment has a modular configuration that includes the above-mentioned parts (busbar fault detection unit, first fault response unit, second fault response unit, and recovery unit). In actual hardware, the CPU (processor) reads the program from the storage medium and executes it, loading the above-mentioned parts onto the main memory, and the busbar fault detection unit, first fault response unit, second fault response unit, and recovery unit are generated on the main memory.

[0071] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0072] 10 Power receiving equipment A1-A3, A4 output signals B1-B3, B4 output signals BA busbar BB busbar BC common bus B3 Output Signal B4 Output Signal C1, C2 output signals CBA1~CBA3 Circuit Breakers CBB1~CBB3 Circuit Breakers CBA1-3, CBB1-3 Circuit Breakers CBAB circuit breaker CBAC circuit breaker CBBC circuit breaker CBCC circuit breaker CTA1~CTA3, CTA4 Current transformer CTB1~CTB3, CTB4 Current transformer CTA-B, CTB-A current transformer CTA1-3, CTB1-3, current transformer CTC1, CTC2 current transformer CTA-1~CTA3 Current transformer CTB-1~CTB3 Current transformer CTCC current transformer DS disconnector F1 Input Conversion Unit F2 Accident Detection Unit F3 DO Unit LA, LB, LC distribution line PS Accident location RLA, RLB, RLC busbar protection relay

Claims

1. A busbar protection device for protecting the busbars of a power receiving facility, comprising: a plurality of individual busbars constituting a parallel multiple line; a common busbar that can be commonly connected to the plurality of individual busbars; a common current transformer provided on the common busbar side of a common circuit breaker provided at the connection point between the common busbar and the plurality of individual busbars; a plurality of current transformers provided on the individual busbar side of the common circuit breaker; and a plurality of individual circuit breakers provided on each of the individual busbars between the common circuit breaker and the plurality of current transformers, which, when the common circuit breaker is tripped, trip the corresponding individual busbar, A busbar fault detection unit detects a busbar fault based on the output of the common current transformer and the multiple current transformers, When the bus fault detection unit detects a bus fault on the common bus based on the output of the common current transformer, the first fault response unit trips the common circuit breaker. A second fault response unit that, after the tripping of the common circuit breaker, detects a bus fault in the corresponding individual bus based on the output of any of the multiple current transformers, trips the corresponding individual circuit breaker. A busbar protection device equipped with a busbar.

2. After the individual circuit breakers have been tripped by the second fault response unit, a reset unit is provided to release the tripped common circuit breaker. Busbar protection device according to claim 1.

3. In a power receiving facility having multiple individual buses constituting multiple parallel lines, and a common bus that can be commonly connected to the multiple individual buses, A common current transformer provided on the common bus side of a common circuit breaker provided at the connection point between the common bus and the plurality of individual buses, A plurality of current transformers are provided on the individual busbar side of the common circuit breaker, In the state in which the common circuit breaker is tripped, a plurality of individual circuit breakers are provided on each of the individual busbars between the common circuit breaker and the plurality of current transformers, and each of the individual busbars trips the corresponding individual busbar. It includes a busbar protection device that protects the busbars, The busbar protection device includes a busbar fault detection unit that detects busbar faults based on the outputs of the common current transformer and the plurality of current transformers, When the bus fault detection unit detects a bus fault on the common bus based on the output of the common current transformer, the first fault response unit trips the common circuit breaker. The system includes a second fault response unit that, after the common circuit breaker has tripped, detects a bus fault in the corresponding individual bus based on the output of any of the multiple current transformers, and trips the corresponding individual circuit breaker. Power receiving equipment.

4. The busbar protection device includes a resetting unit that releases the tripping of the common circuit breaker after the tripping of the individual circuit breakers has been performed by the second fault response unit. The power receiving equipment according to claim 3.

5. A busbar protection method for a power receiving facility comprising: a plurality of individual busbars constituting a parallel multiple line; a common busbar that can be commonly connected to the plurality of individual busbars; a common current transformer provided on the common busbar side of a common circuit breaker provided at the connection point between the common busbar and the plurality of individual busbars; a plurality of current transformers provided on the individual busbar side of the common circuit breaker; and a plurality of individual circuit breakers provided on each of the individual busbars between the common circuit breaker and the plurality of current transformers, which, when the common circuit breaker is tripped, trip the corresponding individual busbar, wherein the busbar protection method provides for the busbar protection of the power receiving facility, A process for detecting a busbar fault based on the output of the common current transformer and the multiple current transformers, In the process of detecting the busbar fault, if a busbar fault is detected on the common busbar, the process of tripping the common circuit breaker is performed. If a bus fault in the corresponding individual bus is detected based on the output of any of the multiple current transformers after the common circuit breaker has been tripped, the process of tripping the corresponding individual circuit breaker is performed. A busbar protection method equipped with [a specific feature].

6. The system includes a process for releasing the tripped common circuit breaker after the tripped individual circuit breakers have been tripped. The busbar protection method according to claim 5.

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