Protection system and method for ship's power distribution system

Abstract

To protect a ship's power distribution system.SOLUTION: A protection system 100 includes first breaker modules Ra1 to Ra4 that are disposed between a power generator and a switch board SWBD and include relays R, second breaker modules Rb1 to Rb4 that are disposed on the switch board and include relays, and third breaker modules Rc1-1 to Rc4-3 that are disposed between the switch board and feeders A-1 to D-3, and include relays. The relays of the second and third breaker modules have the same relay times. On the basis of a magnitude and a direction of a fault current, the third circuit breaker module trips a circuit breaker, and transmits a power distribution maintenance signal to the second circuit breaker module when a fault occurs in the feeder preset to be in charge of the third circuit breaker module, and the second and third circuit breaker modules trip the circuit breaker, and the second circuit breaker module transmits a power distribution maintenance signal to the third circuit breaker module when a fault occurs in the switchboard preset to be in charge of the second circuit breaker module.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system and method for protecting a power distribution system of a ship. [Background technology]

[0002] Generally, ships use many components that require electrical power. For example, a dynamic positioning (DP) ship is a ship equipped with a system that maintains or controls the ship's position and heading using thrusters. It is used for operations such as shuttle tankers and offshore drilling, and if the ship's position changes during operation, it may cause an accident that poses a great risk.

[0003] That is, when a disturbance occurs in a ship's system, a protection function is required that can selectively cut off only the faulty location in order to quickly remove the fault and minimize the faulty section to prevent a ship displacement accident. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Korean Patent Publication No. 10-2019-0051077 Summary of the Invention [Problem to be solved by the invention]

[0005] According to one embodiment of the present invention, there is provided a protection system and a protection method for a power distribution system of a ship, which has a protection function that can selectively shut off only the fault location quickly and accurately when a disturbance occurs in the power system of the ship. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, a protection system for a power distribution system of a ship according to one embodiment of the present invention may include a first circuit breaker module disposed between a generator and a switchboard and having a circuit breaker for cutting off power to be transmitted and a relay for controlling the operation of the circuit breaker, a second circuit breaker module disposed in the switchboard and having a circuit breaker for cutting off power to be transmitted and a relay for controlling the operation of the circuit breaker, and a third circuit breaker module disposed between the switchboard and a feeder and having a circuit breaker for cutting off power to be transmitted and a relay for controlling the operation of the circuit breaker, wherein the relay of the second circuit breaker module and the relay of the third circuit breaker module have the same delay time, and the second circuit breaker module When a fault occurs in a feeder that the third circuit breaker module is pre-set to be responsible for, the relay of the third circuit breaker module and the relay of the third circuit breaker module trip the circuit breaker and transmit a power distribution maintenance signal to the relay of the second circuit breaker module, based on the magnitude and direction of the fault current, respectively. When a fault occurs in a switchboard that the second circuit breaker module is pre-set to be responsible for, the relays of the second and third circuit breaker modules trip the circuit breaker, and the relay of the second circuit breaker module transmits a power distribution maintenance signal to the relay of the third circuit breaker module that is pre-set according to the magnitude and direction of the fault current.

[0007] In order to solve the above-mentioned problems, a method for protecting a power distribution system of a ship according to one embodiment of the present invention includes a first circuit breaker module having a circuit breaker disposed between a generator and a switchboard for cutting off the transmitted power and a relay for controlling the operation of the circuit breaker when a fault occurs in the power distribution system of the ship, a second circuit breaker module disposed in the switchboard for cutting off the transmitted power and a relay for controlling the operation of the circuit breaker, and a third circuit breaker module having a circuit breaker disposed between the switchboard and a feeder for cutting off the transmitted power and a relay for controlling the operation of the circuit breaker, and a first step of confirming the magnitude and direction of a fault current by communicating with each other; a second step of instantaneously tripping the circuit breaker module when the magnitude and direction of the confirmed fault current correspond to a predetermined differential protection fault; The method may include a third step of, if the differential protection fault does not occur but a predetermined feeder-side fault occurs, a relay of a corresponding third circuit breaker module trips the circuit breaker and transmits a power distribution maintenance signal to a relay of the second circuit breaker module; a fourth step of, if the magnitude and direction of the confirmed fault current do not occur, confirming a fault location according to the magnitude and direction of the confirmed fault current, and, if a fault occurs in a switchboard that the second circuit breaker module is previously set to be responsible for, tripping the circuit breaker, and the relay of the second circuit breaker module transmits a power distribution maintenance signal to a relay of a third circuit breaker module that is previously set according to the magnitude and direction of the fault current; and a fifth step of tripping a circuit breaker of a first circuit breaker module of a switchboard where the fault occurs. [Effects of the Invention]

[0008] According to one embodiment of the present invention, in a power distribution system of a ship, it is possible to selectively cut off only the faulty section, thereby minimizing the fault range and damage, and to quickly cut off the fault in response to a disturbance, thereby improving the safety of the ship's power system. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a configuration diagram illustrating an example of a protection system for a power distribution system of a ship according to an embodiment of the present invention. [Figure 2] FIG. 10 is a configuration diagram illustrating, in outline, another example of a protection system for a power distribution system of a ship according to a preferred embodiment of the present invention. [Figure 3] 3 is a flowchart showing the general operation of a method for protecting a power distribution system of a ship according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments will now be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

[0011] FIG. 1 is a schematic diagram showing an example of a protection system for a power distribution system of a ship according to one embodiment of the present invention, and FIG. 2 is a schematic diagram showing another example of a protection system for a power distribution system of a ship according to one embodiment of the present invention.

[0012] Referring to FIG. 1 , an example 100 of a protection system for a power distribution system of a ship according to an embodiment of the present invention may include a plurality of generators G1, G2, G3, G4, a plurality of feeders A-1, A-2, A-3, B-1, B-2, B-3, C-1, C-2, C-3, D-1, D-2, D-3 to which power is supplied from the generators among the plurality of generators G1, G2, G3, G4, and a plurality of buses (BUS) BUS A, BUS B, BUS C, BUS D of a switchboard that distributes power to the plurality of generators G1, G2, G3, G4 and the plurality of feeders A-1, A-2, A-3, B-1, B-2, B-3, C-1, C-2, C-3, D-1, D-2, D-3 to which power is supplied from the generators among the plurality of generators G1, G2, G3, G4, and The system may include a plurality of first circuit breaker modules Ra1, Ra2, Ra3, Ra4 connected between buses BUS A, BUS B, BUS C, and BUS D, a plurality of second circuit breaker modules Rb1, Rb2, Rb3, Rb4 connected between buses BUS A, BUS B, BUS C, and BUS D, and a plurality of third circuit breaker modules Rc1-1, Rc1-2, Rc1-3, Rc2-1, Rc2-2, Rc2-3, Rc3-1, Rc3-2, Rc3-3, Rc4-1, Rc4-2, Rc4-3 connected between feeders A-1, A-2, A-3, B-1, B-2, B-3, C-1, C-2, C-3, D-1, D-2, and D-3 to which power is distributed from the buses BUS A, BUS B, BUS C, and BUS D.

[0013] The plurality of first circuit breaker modules Ra1, Ra2, Ra3, Ra4, the plurality of second circuit breaker modules Rb1, Rb2, Rb3, Rb4 and the plurality of third circuit breaker modules Rc1-1, Rc1-2, Rc1-3, Rc2-1, Rc2-2, Rc2-3, Rc3-1, Rc3-2, Rc3-3, Rc4-1, Rc4-2, Rc4-3 are respectively connected to relays R and circuit breakers Sa1, Sa2, Sa3, Sa4, Sc1-1, Sc1-2, Sc1-3, Sc2-1, Sc2-2, Sc2-3, Sc3-1, Sc3-2, Sc3-3, Sc4-1, Sc4-2, Sc4-3 or bus ties BT 1-1, BT 1-2, BT 2-1, BT 2-2, BT 3-1, BT The relays R may include relays BT1-1, BT1-2, BT2-1, BT2-2, BT3-1, BT3-2, BT4-1, BT4-2, and each of the relays R can communicate with each other (not shown) to recognize the location of the fault and the direction of the fault current, and the circuit breakers Sa1, Sa2, Sa3, Sa4, Sc1-1, Sc1-2, Sc1-3, Sc2-1, Sc2-2, Sc2-3, Sc3-1, Sc3-2, Sc3-3, Sc4-1, Sc4-2, Sc4-3 or bus ties BT1-1, BT1-2, BT2-1, BT2-2, BT3-1, BT3-2, BT4-1, BT4-2 can interrupt or maintain the power transmission path by controlling the relays R.

[0014] Each of the relays R may be configured with hardware, a combination of hardware and software, software, or running software, and may include at least one processing unit and memory. Here, the processing unit may include at least one of a central processing unit (CPU), a graphics processing unit (GPU), a microprocessor, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), etc., and may have multiple cores. The memory may be volatile memory (e.g., RAM, etc.), non-volatile memory (e.g., ROM, flash memory, etc.), or a combination thereof. Furthermore, each of the relays R may include a communication connection unit that enables communication with each other, and here, the communication connection unit may be various, such as a modem, a network interface card (NIC), an integrated network interface, a radio frequency transmitter / receiver, an infrared port, a USB connection, etc.

[0015] Furthermore, as shown in FIG. 2, as another example 200 of a protection system for a ship power distribution system according to one embodiment of the present invention, a ring configuration may be used in which bus ties BT4-1 and BT4-2 are formed between the initial bus BUS A and the terminal bus BUS D among multiple buses BUS A, BUS B, BUS C, and BUS D.

[0016] 1 and 2 show first to fourth generators G1, G2, G3, and G4 and buses BUS A, BUS B, BUS C, and BUS D, but are not limited thereto. Also, in FIGS. 1 and 2, the bus ties of the second circuit breaker modules Rb1, Rb2, Rb3, and Rb4 may be configured with one switch BT1 and a relay R, or two switches BT1-1 and BT1-2 and a relay R. While FIGS. 1 and 2 show that one bus tie may be configured with one switch BT1 and a relay R, or two switches BT1-1 and BT1-2 and a relay R, it goes without saying that the same can be applied to the remaining bus ties BT2, BT3, and BT4.

[0017] FIG. 3 is a flowchart showing a schematic operation of a method for protecting a power distribution system of a ship according to one embodiment of the present invention.

[0018] Referring to FIG. 3 in addition to FIGS. 1 and 2, first, when a fault occurs during operation, a plurality of first circuit breaker modules Ra1, Ra2, Ra3, Ra4 connected between each of the plurality of generators G1, G2, G3, G4 and the corresponding buses BUS A, BUS B, BUS C, BUS D of the switchboard (SWBD), a plurality of second circuit breaker modules Rb1, Rb2, Rb3, Rb4 connected between each of the plurality of buses BUS A, BUS B, BUS C, BUS D of the switchboard (SWBD), and a plurality of second circuit breaker modules Rb1, Rb2, Rb3, Rb4 connected between each of the plurality of buses BUS A, BUS B, BUS C, BUS D of the switchboard (SWBD) are broken. The relays R of the plurality of third circuit breaker modules Rc1-1, Rc1-2, Rc1-3, Rc2-1, Rc2-2, Rc2-3, Rc3-1, Rc3-2, Rc3-3, Rc4-1, Rc4-2, and Rc4-3 connected between the plurality of feeders A-1, A-2, A-3, B-1, B-2, B-3, C-1, C-2, C-3, D-1, D-2, and D-3 to which power is distributed from the bus D can communicate with each other to confirm the magnitude and direction of the fault current (S1, S2) (first stage).

[0019] If the magnitude and direction of the fault current confirmed through communication between the relays of the above-mentioned multiple first to third circuit breaker modules corresponds to a pre-set differential protection fault (S3), the circuit breaker module can be instantly tripped (S4) (second stage).

[0020] Here, differential protection means that when a fault occurs in a line or electrical equipment to be protected in an electrical system, the fault is identified in the protected section based on the difference in the magnitude of the current generated between the protection devices. This is generally a basic method for protecting generators and transformers, and a detailed description thereof will be omitted.

[0021] Meanwhile, a delay time can be set when setting the operation time of each relay of the first to third circuit breaker modules. The delay time of each relay of the second and third circuit breaker modules can be set to the same, and the delay time of each relay of the first circuit breaker module can be set to be slower than the delay time of each relay of the second and third circuit breaker modules. For example, the delay time of each relay of the second and third circuit breaker modules can be set to 100 ms, and the delay time of each relay of the first circuit breaker module can be set to 300 ms. By setting the relay time of the second circuit breaker module to the same delay time of each relay of the third circuit breaker module, 100 ms, the existing coordination time (200 ms) between the load side and the bus tie can be reduced. By reducing the circuit breaker trip time when a fault occurs, the fault can be shut down more quickly and the transient stability of the electrical system can be improved.

[0022] Meanwhile, instantaneous tripping means that the tripping action is performed without delay in response to an internal fault, and the time range for instantaneous tripping varies depending on the relay manufacturer, but can be set to about 30 to 50 ms.

[0023] If the magnitude and direction of the confirmed fault current do not correspond to the above-mentioned differential protection fault but correspond to a pre-defined feeder-side fault (S5), the circuit breaker of the corresponding third circuit breaker module is tripped, and the relay of the corresponding third circuit breaker module can transmit a power distribution maintenance signal to the relay of the corresponding second circuit breaker module (S6) (third step).

[0024] In addition, if the magnitude and directionality of the confirmed fault current do not correspond to the differential protection fault or the feeder side fault, the fault location is confirmed according to the magnitude and directionality of the confirmed fault current, and the circuit breaker of the second circuit breaker module and the circuit breaker of the third circuit breaker module of the switchboard where the fault occurred are tripped, and the relay of the second circuit breaker module transmits a power distribution maintenance signal to the relay of the third circuit breaker module that has been set in advance according to the magnitude and directionality of the fault current (S7) (fourth step).

[0025] Thereafter, the circuit breaker of the first circuit breaker module of the switchboard where the fault occurred can be tripped (S8) (fifth step).

[0026] Meanwhile, in the third and fourth steps, the breakers of the breaker modules that do not correspond to the fault location can be prevented from tripping due to the breaker trip of the corresponding breaker module and the preset block logic operation.

[0027] The following table shows the block logic of a protection system and method for a power distribution system of a ship according to an embodiment of the present invention.

[0028] [Table 1-1] [Table 1-2] [Table 1-3] [Table 1-4] [Table 1-5]

[0029] 1 or 2 and Table 1 above, the power system (bus system) to which the protection system and protection method for a power distribution system of a ship according to an embodiment of the present invention is applied can be classified into a ring bus system, a closed bus system, a two-split system, a three-split system, etc. To explain the above block logic, a closed bus system and a two-split system will be described as examples with reference to Table 1.

[0030] First, in the closed bus system, when a fault occurs in each of the multiple buses (Bus A Fault, Bus B Fault, Bus C Fault, Bus D Fault), the bus ties of the multiple buses (e.g., BT 1-1 and BT 1-2 (Bus-Tie 1), BT 2-1 and BT 2-2 (Bus-Tie 2), BT 3-1 and BT 3-2 (Bus-Tie 3)) can be opened. For example, in the power system shown in FIGS. 1 and 2, when a fault occurs in the first bus BUS A, the fault current does not flow to the corresponding feeder but flows into the location where the fault occurred. Therefore, the relays R of the second circuit breaker modules Rb1, Rb2, and Rb3 communicate with each other and can confirm that the current flows into the side where the fault occurred. The direction of the fault current can be determined based on the direction in which it flows relative to the circuit breaker, and the direction can be determined arbitrarily. In the case of a bus tie, if the fault current flows from the second bus BUS B to the first bus BUS A, it is defined as 67F; if it flows from the first bus BUS A to the second bus BUS B, it is defined as 67R; if it flows from the bus to the feeder, it is defined as 67F; and if it flows from the feeder to the bus, it is defined as 67R. For example, with the first bus tie as the reference, if current flows into the first bus BUS A, it is defined as 67F; and if current flows into the second bus BUS B, it is defined as 67R. The descriptions and definitions of 67F and 67R can be changed according to the user's selection.

[0031] 1 and 2, when a fault occurs in the first bus BUS A, the relays R of the second circuit breaker modules Rb1, Rb2, and Rb3 communicate with each other and can confirm that current is flowing into the first bus BUS A. Current flows in the opposite direction in the first to third bus ties Bus-Tie 1, Bus-Tie 2, and Bus-Tie 3 (BT1-1, BT1-2, BT2-1, BT2-2, BT3-1, and BT3-2), so in this case the first bus ties BT1-1 and BT1-2 operate to cut off the current flowing into the first bus BUS A. Then, the relays R of the third circuit breaker modules Rc1-1, Rc1-2, and Rc1-3 at the fault location operate the circuit breakers Sc1-1, Sc1-2, and Sc1-3 to cut off the inflow of current. At this time, the first bus ties BT1-1 and BT1-2 transmit block signals to the third circuit breaker modules Rc2-1, Rc2-2, and Rc2-3 of the second feeder (Feeder B) and the first circuit breaker modules Ra1, Ra2, Ra3, and Ra4, preventing the circuit breakers Sc2-1, Sc2-2, and Sc2-3 of the third circuit breaker module and the circuit breakers Sa1, Sa2, Sa3, and Sa4 of the first circuit breaker module from operating (block logic in Figure 3).As described above, the second circuit breaker modules BT2-1, BT2-2, BT3-1, and BT3-2 also transmit block signals in the same manner as shown in Table 1, preventing the second and third circuit breakers from operating.

[0032] Here, according to the requirement that the generators, even if they are the generators corresponding to the faulty part, should open later than the circuit breakers in the bus ties, the first to fourth generators G1, G2, G3, G4 (G1 to G4) can maintain power generation operation. Then, as in the fifth step of Figure 3, the circuit breaker Sa1 of the first circuit breaker module Ra1 can be operated to cut off the power transmission.

[0033] Similarly to the above, when a fault occurs in the second to fourth buses (BUS B Fault, BUS C Fault, BUS D Fault), the circuit breaker at the corresponding fault location is operated according to the direction of the fault current 67R, 67F, and power transmission can be maintained without operating the circuit breakers in the circuit breaker modules that do not correspond to the fault location.

[0034] Next, in the two-split system, when the second bus tie Bus-Tie 2 (BT2-1, BT2-2) is open and the first and third bus ties Bus-Tie 1 and Bus-Tie 3 (BT1-1, BT1-2, BT3-1, BT3-3) are closed, if a fault occurs in the first bus BUS A (BUS A Fault), the current flowing into the first bus tie Bus-Tie 1 (BT1-1, BT1-2) is detected as flowing in the reverse direction 67R by the relay R, which trips the first bus tie Bus-Tie 1 (BT1-1, BT1-2) to interrupt the fault. At this time, in order to cut off only the faulted section, a block signal is sent to the circuit breaker modules that do not correspond to the fault location, and power transmission can be maintained without operating the circuit breakers (second feeder (Feeder B) (B-1, B-2, B-3) and first to fourth generators G1, G2, G3, G4 (G1 to G4)). If a fault occurs in second bus B (BUS B Fault), the current flowing into first bus tie 1 (BT1-1, BT1-2) can be confirmed as forward 67F by relay R, and first bus tie 1 (BT1-1, BT1-2) is tripped to cut off the fault. At this time, in order to cut off only the faulted section, a block signal is sent to the circuit breaker modules that do not correspond to the fault location, and power transmission can be maintained without operating the circuit breakers (first feeder A (A-1, A-2, A-3) and first to fourth generators G1, G2, G3, G4 (G1 to G4)). If a fault occurs in third bus C (BUS C Fault), the current flowing into third bus tie 3 (BT3-1, BT3-2) is detected as flowing in the reverse direction 67R by relay R, and third bus tie 3 (BT3-1, BT3-2) is tripped to cut off the fault. At this time, in order to cut off only the faulted section, a block signal can be transmitted to the circuit breaker modules that do not correspond to the faulted location, thereby maintaining power transmission without operating the circuit breakers (4th feeder (Feeder D) (D-1, D-2, D-3) and 1st to 4th generators G1, G2, G3, G4 (G1 to G4)).If a fault occurs in the fourth bus (BUS D Fault), the current flowing into the third bus tie 3 (BT3-1, BT3-2) is detected as forward current by relay R, which trips the third bus tie 3 (BT3-1, BT3-2) to interrupt the fault. At this time, to interrupt only the faulted section, a block signal is sent to the circuit breaker modules that do not correspond to the fault location, preventing the circuit breakers from operating and maintaining power transmission (third feeder (Feeder C) (C-1, C-2, C-3) and first through fourth generators G1, G2, G3, G4 (G1-G4)).

[0035] In addition, in the two-split system, when the first bus tie Bus-Tie 1 (BT1-1, BT1-2) is open and the second and third bus ties Bus-Tie 2, Bus-Tie 3 (BT2-1, BT2-2, BT3-1, BT3-3) are closed, the following cases occur: when a fault occurs in the second bus B (BUS B Fault), when a fault occurs in the third bus Bus C (BUS C Fault), and when a fault occurs in the fourth bus Bus D (BUS D Fault). When a fault occurs in the second bus B (BUS B Fault), the current flowing into the second and third bus ties Bus-Tie 2, Bus-Tie 3 (BT2-1, BT2-2, BT3-1, BT3-3) is detected as flowing in the reverse direction 67R by the relay R, and the second bus tie Bus-Tie 3 is closed to interrupt the fault. When the fault occurs, relay R of the second circuit breaker module of the second and third bus ties (Bus-Tie 2 and Bus-Tie 3) (BT2-1, BT2-2, BT3-1, BT3-3) that picked up the fault current sends a block signal to shut off only the faulted section. The second bus tie (Bus-Tie 2) (BT2-1, BT2-2) sends a block signal to the corresponding relays of the third feeder (Feeder C) and the first through fourth generators G1 through G4, and the third bus tie (Bus-Tie 3) (BT3-1, BT3-3) sends a block signal to the corresponding relays of the fourth feeder (Feeder D) and the first through fourth generators G1 through G4.

[0036] As a result, if a fault occurs in the second bus BUS B while the above-mentioned two-split system is in operation, relay R of the second circuit breaker module of the second and third bus ties Bus-Tie2 and Bus-Tie3 (BT2-1, BT2-2, BT3-1, BT3-3) picks up the fault current, and relay elements 67F and 67R determine the direction of the fault location, tripping the second bus tie Bus-Tie2 (BT2-1, BT2-2). The second bus ties Bus-Tie2 (BT2-1, BT2-2) and the third bus ties Bus-Tie3 (BT3-1, BT3-3) then transmit block signals, preventing the circuit breakers of the feeders and generators of the non-faulty buses from operating.

[0037] Faults in the third bus BUS C and the fourth bus BUS D can also be handled using the same principles as described above.

[0038] If a fault occurs in the third bus, BUS C, the relays of the second bus tie, Bus-Tie2 (BT2-1, BT2-2), pick up 67F, and the relays of the third bus tie, Bus-Tie3 (BT3-1, BT3-3), pick up 67R. Relay elements 67F and 67R make a directional judgment regarding the fault location, tripping the second bus tie Bus-Tie2 (BT2-1, BT2-2) and the third bus tie Bus-Tie3 (BT3-1, BT3-3), and the relays of the second bus ties Bus-Tie2 (BT2-1, BT2-2) and the third bus ties Bus-Tie3 (BT3-1, BT3-3) transmit a block signal, preventing the circuit breakers of the feeders and generators of the non-faulty buses from operating (the second bus tie Bus-Tie2 (BT2-1, BT2-2) is connected to the second feeder (Feeder B) and the first to fourth generators G1 to G4, and the third bus tie Bus-Tie3 (BT3-1, BT3-3) is connected to the fourth feeder (Feeder D) and the first to fourth generators G1 to G4).

[0039] The block logic defined in Table 1 above determines whether or not a block signal is transmitted depending on which relay element the relays of bus ties 1 to 3 pick up for all possible fault cases. As shown in the bottom row of Table 1, when the relay of bus tie 1 (BT1-1, BT1-2) picks up 67R, it can transmit a block signal to the relay of the third circuit breaker module of feeder 2 (Feeder B), and when it picks up 67F, it can transmit a block signal to the relay of the third circuit breaker module of feeder 1 (Feeder A). Furthermore, when the relay of the second bus tie Bus-Tie2 (BT2-1, BT2-2) picks up 67R, when it picks up 67F on the third feeder (Feeder C), it can transmit a block signal to the relay of the third circuit breaker module on the second feeder (Feeder B). Similarly, when the relay of the third bus tie Bus-Tie3 (BT3-1, BT3-3) picks up 67R, when it picks up 67F on the fourth feeder (Feeder D), it can transmit a block signal to the relay of the third circuit breaker module on the third feeder (Feeder C).

[0040] As described above, according to the present invention, it is possible to selectively trip only the faulty feeder according to the directionality of the fault current, thereby minimizing the fault section and damage. When a dynamic positioning closed bus system is operated using block logic using directional elements as described above, it is possible to quickly cut off the fault in response to a disturbance, thereby improving the stability of the ship's power system.

[0041] The present invention described above is not limited by the above-mentioned embodiments and the attached drawings, but is limited by the claims below, and it can be easily understood by those having ordinary knowledge in the technical field to which the present invention pertains that the configuration of the present invention can be changed and modified in various ways within the scope that does not deviate from the technical idea of the present invention. [Explanation of symbols]

[0042] 100: An example of a protection system for a power distribution system of a ship according to an embodiment of the present invention 200: Another example of a protection system for a power distribution system of a ship according to an embodiment of the present invention

Claims

1. a plurality of first circuit breaker modules each having a circuit breaker disposed between the generator and a plurality of switchboards for interrupting power transmission and a relay for controlling the operation of the circuit breaker; a plurality of second circuit breaker modules disposed on the plurality of switchboards, each having a circuit breaker for interrupting power transmission and a relay for controlling operation of the circuit breaker; and a plurality of third circuit breaker modules each having a circuit breaker for interrupting power transmission between the plurality of switchboards and a feeder and a relay for controlling operation of the circuit breaker, When a fault occurs in the power distribution system of the ship, the relays of the first circuit breaker modules, the relays of the second circuit breaker modules, and the relays of the third circuit breaker modules communicate with each other to confirm the magnitude and direction of the fault current; the relays of the second circuit breaker modules and the relays of the third circuit breaker modules have the same delay time; a delay time of the relay of the first circuit breaker module is set to be slower than a delay time of the relay of the second circuit breaker module and a delay time of the relay of the third circuit breaker module; The relays of the first circuit breaker modules, the relays of the second circuit breaker modules, and the relays of the third circuit breaker modules each perform one of the following operations based on the magnitude and directionality of the confirmed fault current: When a fault occurs in a feeder that is previously assigned to each of the plurality of third circuit breaker modules, a relay of the corresponding third circuit breaker module trips the corresponding circuit breaker and transmits a power distribution maintenance signal to relays of the plurality of second circuit breaker modules; When a fault occurs in a switchboard that is previously set to be handled by the plurality of second circuit breaker modules, the relays of the corresponding second and third circuit breaker modules trip the corresponding circuit breakers, and the relay of the second circuit breaker module transmits a power distribution maintenance signal to the relays of the plurality of third circuit breaker modules that are previously set according to the magnitude and direction of the fault current; When a fault occurs in at least one switchboard among the plurality of switchboards, each of the relays of the plurality of second circuit breaker modules transmits the power distribution maintenance signal to a relay of a third circuit breaker module connected to an adjacent switchboard among the plurality of switchboards in an opposite direction to the fault current direction based on the magnitude and direction of the fault current, and the relay of a second circuit breaker module among the plurality of second circuit breaker modules, whose circuit breaker is open, does not transmit the power distribution maintenance signal to the relay of the third circuit breaker module.

2. 2. The protection system for a power distribution system according to claim 1, wherein the second circuit breaker module includes at least one circuit breaker disposed between adjacent switchboards among the plurality of switchboards, and a relay for controlling operation of the at least one circuit breaker, for each space between adjacent switchboards among the plurality of switchboards.

3. 2. The protection system for a power distribution system of a ship according to claim 1, wherein the second circuit breaker module includes two circuit breakers arranged between adjacent switchboards among the plurality of switchboards, and two relays that respectively control operation of the two circuit breakers, for each space between adjacent switchboards among the plurality of switchboards.

4. a first step in which, when a fault occurs in the ship's power distribution system, relays of a plurality of first circuit breaker modules, each of which is disposed between a generator and a plurality of switchboards and has a circuit breaker for cutting off the power being transmitted and a relay for controlling the operation of the circuit breaker; a plurality of second circuit breaker modules, each of which is disposed on the switchboards and has a circuit breaker for cutting off the power being transmitted and a relay for controlling the operation of the circuit breaker; and a plurality of third circuit breaker modules, each of which is disposed between the switchboards and a feeder and has a circuit breaker for cutting off the power being transmitted and a relay for controlling the operation of the circuit breaker, communicate with each other to confirm the magnitude and direction of the fault current; a second step of instantaneously tripping the circuit breaker module if the magnitude and direction of the identified fault current correspond to a predetermined differential protection fault; a third step of, if the magnitude and direction of the confirmed fault current do not correspond to the differential protection fault but correspond to a preset feeder-side fault, tripping the corresponding third circuit breaker module relay and transmitting a power distribution maintenance signal to the second circuit breaker module relay; a fourth step of confirming a fault location according to the magnitude and direction of the confirmed fault current if the magnitude and direction of the confirmed fault current do not correspond to the differential protection fault or the feeder side fault, and if a fault occurs in a switchboard that is pre-set to be handled by the second circuit breaker module, the relays of the second and third circuit breaker modules connected to the switchboard where the fault occurs trip the corresponding circuit breaker, and the relay of the second circuit breaker module transmits a power distribution maintenance signal to the relay of the third circuit breaker module that is pre-set according to the magnitude and direction of the fault current; a fifth step of tripping the circuit breaker of the first circuit breaker module of the switchboard in which the fault occurred; Including, In the first stage, the relay of the second circuit breaker module and the relay of the third circuit breaker module have the same delay time; In the first stage, a delay time of the relay of the first circuit breaker module is set to be slower than delay times of the relay of the second circuit breaker module and the relay of the third circuit breaker module; The fourth stage is and when a fault occurs in at least one switchboard among the plurality of switchboards, each of the relays of the plurality of second circuit breaker modules transmits the power distribution maintenance signal to a relay of a third circuit breaker module connected to an adjacent switchboard among the plurality of switchboards in an opposite direction to the fault current direction, based on the magnitude and directionality of the fault current, and the relay of a second circuit breaker module among the plurality of second circuit breaker modules, whose circuit breaker is open, does not transmit the power distribution maintenance signal to the relay of the third circuit breaker module.

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