Device

Abstract

This device comprises a first breaker unit disposed on a first-direction side of a power line, a second breaker unit disposed on a second-direction side of the power line, and a third two-way breaker unit disposed on the side of a branch line extending from a branch point in the power line.

Description

Device

[0001] The present invention relates to protection and coordination of power supply systems.

[0002] In general, in power supply systems, protective coordination is implemented by appropriately setting the settings of circuit breaker sensitivity, operating time, etc., so that in the event of an accident, the faulty part can be quickly isolated and other healthy circuits can be protected.

[0003] For example, if a short circuit occurs in a section of a power line near a load connected to the end of a power supply system, a very large short-circuit current will usually flow through the power line, causing a circuit breaker to instantly operate and disconnect the short-circuited area from the power supply.

[0004] Meanwhile, in recent years, the introduction of ring-type (also referred to as loop-type) power supply systems has been progressing in various regions (for example, Non-Patent Document 1). A ring-type power supply system is a power supply system in which various power sources (such as photovoltaic power generation (PV)), storage batteries, electric vehicles (EVs), etc. are connected in a ring shape with power lines. In such a power supply system, protection coordination is achieved by "cascade tripping" using multiple circuit breakers. Cascade tripping is a mechanism in which, in an electrical system where an accident has occurred, circuit breakers are set to trip equipment in order, starting from the lower-level (load side), in order to minimize the scope of the power outage.

[0005] Summary of opinions on issues related to the construction of regional microgrids and the implementation of power distribution projects (Ministry of Economy, Trade and Industry) https: / / www.meti.go.jp / shingikai / energy_environment / energy_resource / pdf / 015_04_00.pdf (Retrieved November 30, 2023) Study on short-circuit protection methods for bus-wired outdoor DC power supply systems (2023 National Convention of the Institute of Electrical Engineers of Japan, 4-153)

[0006] As mentioned above, storage batteries are generally connected to ring-type power supply systems. However, because storage batteries act as a higher-level power source (power source) when discharging and as a lower-level load (load) when charging, the direction and route of current flow cannot be uniquely determined in a power supply system with storage batteries connected.

[0007] Therefore, it has been difficult to achieve protection coordination in a ring-type power supply system connected to storage batteries. Note that this issue is not limited to ring-type power supply systems, but can occur in any power supply system connected to storage batteries.

[0008] The present invention has been made in view of the above points, and an object of the present invention is to provide a technique that enables appropriate protection coordination in a power supply system.

[0009] According to the disclosed technology, there is provided a device comprising: a first circuit breaker arranged on a first direction side of a power line; a second circuit breaker arranged on a second direction side of the power line; and a third bidirectional circuit breaker arranged on a branch line side extending from a branch point on the power line.

[0010] The disclosed technology provides a technology that enables appropriate protection coordination in a power supply system.

[0011] 1 is a diagram illustrating an example of the configuration of a star-type power supply system. FIG. 2 is a diagram illustrating an example of the configuration of a ring-type (loop-type) power supply system. FIG. 3 is a diagram illustrating an example of the configuration of a power supply system according to an embodiment of the present invention. FIG. 4 is a diagram illustrating an example of a unidirectional breaking unit. FIG. 5 is a diagram illustrating an example of a bidirectional breaking unit. FIG. 6 is a diagram illustrating an example of the configuration of a three-way circuit breaker 300. FIG. 7 is a diagram illustrating a premise for explaining an example of the operation of the three-way circuit breaker 300. FIG. 8 is a diagram illustrating an example of state detection. FIG. 9 is a diagram illustrating an example of state detection. FIG. 10 is a diagram illustrating an example of state detection. FIG. 11 is a diagram illustrating an example of control for a state. FIG. 12 is a diagram illustrating an example of control for a state. FIG. 13 is a diagram illustrating an example of control for a state. FIG. 14 is a diagram illustrating an example of control for a state. FIG. 15 is a diagram illustrating an example of a case where the tripping threshold is lowered. FIG. 16 is a diagram illustrating an example of the configuration of a three-way circuit breaker 300. FIG. 17 is a diagram illustrating an example of setting values ​​of each tripping unit. FIG. 18 is a diagram illustrating a processing flow of the three-way circuit breaker 300. FIG. 19 is a diagram summarizing the operation of the flow. FIG. 19 is a diagram illustrating an example of operation when the tripping threshold is increased. FIG. 19 is a diagram illustrating an example of operation when the tripping threshold is increased. FIG. 19 is a diagram illustrating an example of operation when the tripping threshold is decreased or a circuit is closed. FIG. 19 is a diagram illustrating an example of operation when the tripping threshold is decreased or a circuit is closed. FIG. 1 is a diagram for explaining a specific example of the flow from measurement to control in a three-way circuit breaker 300. FIG. 2 is a diagram for explaining an example of a loop wiring type power supply system. FIG. 3 is a diagram for explaining an example of a bus wiring type power supply system. FIG. 4 is a diagram for explaining a configuration example of a three-way circuit breaker 300 in a modified example 1. FIG. 5 is a diagram for explaining an operation example 1. FIG. 6 is a diagram for explaining an operation example 2. FIG. 7 is a diagram for explaining an embodiment 1. FIG. 8 is a diagram for explaining an embodiment 2. FIG. 9 is a diagram for explaining an embodiment 3. FIG. 10 is a diagram for explaining an example of the hardware configuration of a control device.

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0013] The power supply system described below is a DC power supply system, but the application of the technology according to the present invention is not limited to DC power supply systems.

[0014] (Regarding the Issues) Conventional power supply systems include, for example, star-type power supply systems and ring-type power supply systems. Star-type power supply systems are mainly used to supply power indoors. Ring-type power supply systems are used not only to supply power indoors but also to supply power to outdoor devices such as EVs.

[0015] An example of the configuration of a star-type power supply system is shown in Fig. 1. The power supply system shown in Fig. 1 is a power supply system that supplies power in one direction from customer building A to customer building B, customer building C, and customer building D.

[0016] As shown in Figure 1, in this power supply system, a circuit breaker is installed in each system. This makes it possible to open only the circuit breaker of the system in which a short circuit occurs, and isolate the short circuit point from the electrical circuit. The example in Figure 1 shows a case in which a short circuit occurs in the system to which customer building D is connected. In this system, there is no need for protective coordination. Examples of circuit breakers that can be used include fuses, CBs (Circuit Breakers), and DC circuit breakers. Examples of DC circuit breakers include mechanical circuit breakers, semiconductor circuit breakers (which may also be called semiconductor circuit breakers), and hybrid circuit breakers, which are a hybrid of mechanical and semiconductor circuit breakers.

[0017] An example of the configuration of a ring-type (or loop-type) power supply system is shown in Fig. 2. As shown in Fig. 2, this power supply system is a power supply system in which various power sources (such as photovoltaic power generation (PV)), storage batteries, electric vehicles (EVs), etc. are connected in a ring shape by power lines.

[0018] This power supply system is equipped with multiple circuit breakers. Protection coordination is achieved through "cascade tripping" consisting of multiple circuit breakers. As mentioned above, cascade tripping is a mechanism in which circuit breakers are set to trip equipment in order, starting with the lower-level (load side) equipment in an electrical system in the event of an accident, in order to keep the scope of the power outage as small as possible. In cascade tripping, circuit breakers connected to lower levels must trip the current faster (shorter time after the accident occurs) than circuit breakers connected to higher levels.

[0019] In the prior art, as shown in FIG. 2 , it is conceivable that the circuit breakers are classified as upper / lower based solely on their placement on the power supply system, and that setting values ​​(e.g., current value, voltage value, time limit (hours), etc.) are set for the upper circuit breaker 1 and the lower circuit breaker 2 so that the lower circuit breaker 2 trips before the upper circuit breaker 1.

[0020] However, because storage batteries generally connected to a ring-type power supply system act as a host (power source) when discharging and as a host (load) when charging, the direction and route of current in a power supply system connected to a storage battery are not uniquely determined. This makes it difficult to achieve protection coordination by setting the circuit breaker settings based on the concept of "cascade breaking" during design.

[0021] The configuration and operation of a system that solves the above problems will be described below.

[0022] (Example of Overall System Configuration) Fig. 3 shows an example of the configuration of a power supply system according to this embodiment. As shown in Fig. 3, in the power supply system according to this embodiment, a three-way circuit breaker 300 is provided at a branch point, which is an intersection of a trunk line and a branch line extending to a consumer. The "three-way circuit breaker 300" may also be referred to as a "device."

[0023] In this embodiment, a semiconductor circuit breaker having a semiconductor element is used as the circuit breaker, which is a component of the three-way circuit breaker 300, and therefore the three-way circuit breaker 300 may be called a "three-way semiconductor circuit breaker 300." However, the configuration of the three-way circuit breaker 300 is not limited to one that uses a semiconductor circuit breaker.

[0024] Each consumer may have any of a load, a storage battery, a power generation device using renewable energy, an EV (electric vehicle), etc. However, in this embodiment, it is assumed that at least one of the multiple consumers is a storage battery.

[0025] Each three-way circuit breaker 300 in this embodiment includes two one-way circuit breakers on the trunk line and a bidirectional circuit breaker connected to the branch line. Each one-way circuit breaker is capable of interrupting one of the two currents flowing through the one-way circuit breaker. The bidirectional circuit breaker is capable of interrupting each of the two currents.

[0026] Each breaker can perform a break operation based on a set value (e.g., current value, voltage value, time limit (hours), etc.) according to the direction of the current. In the following, a case where a current threshold value is used as the set value will be mainly described as an example.

[0027] For example, when a current flows from consumer B to consumer A, the threshold (tripping threshold) of the bidirectional circuit breaker connected to the branch line of consumer A can be set to be smaller than the thresholds of any other circuit breakers on the current path that can trip the direction of the current. This allows, for example, if a short circuit occurs on the branch line connected to consumer A, the bidirectional circuit breaker connected to consumer A to quickly trip the current. Furthermore, if the current flow direction changes, appropriate cooperative operation can be performed by setting a threshold according to the changed current.

[0028] As will be described later, in addition to the above example (basic example), a unidirectional interrupting unit may be used for the interrupting unit connected to the branch line inside three-way circuit breaker 300. Also, all three interrupting units inside three-way circuit breaker 300 may be bidirectional interrupting units.

[0029] (Regarding the unidirectional cutoff unit and the bidirectional cutoff unit) Here, examples of the unidirectional cutoff unit and the bidirectional cutoff unit will be described. Fig. 4 shows an example of a unidirectional cutoff unit. As shown in Fig. 4, the unidirectional cutoff unit has one semiconductor element such as a MOSFET and parts indicated by A and B. A is, for example, a diode, and B is, for example, a capacitor.

[0030] An example of a bidirectional cutoff unit is shown in Figure 5. As shown in Figure 5, the bidirectional cutoff unit has two semiconductor elements such as MOSFETs and parts indicated by A to D. The two semiconductor elements are connected in series in the opposite directions. A and D are, for example, diodes, and B and C are, for example, capacitors.

[0031] The one-way interrupting section may be called a one-way semiconductor circuit breaker, and the two-way interrupting section may be called a two-way semiconductor circuit breaker.

[0032] (Issues related to tripping thresholds and solutions) Non-Patent Document 2 describes that protective coordination is achieved by appropriately setting tripping thresholds in a power supply system. However, the tripping thresholds of each tripping unit are constant (fixed).

[0033] For example, in the loop-type (or bus-type) wiring shown in Figure 3, if the tripping threshold of each breaker is constant (fixed), when an imbalance in power interchange (power source or load) occurs, the current will be limited by the tripping threshold, and there is a possibility that the system's installed capacity will not be used effectively.

[0034] For example, in the configuration of Figure 3, suppose the threshold value of the bidirectional circuit breaker connected to consumer A in the direction toward consumer A is set to a fixed value of 10 A. In this case, even if consumer B requests that consumer A supply a current of 30 A, the current of 30 A cannot be supplied because the circuit breaker threshold value of the bidirectional circuit breaker connected to consumer A is 10 A, and the request cannot be met. Therefore, there is a possibility that the power supply capacity of consumer B will be wasted.

[0035] Therefore, in this embodiment, the three-way circuit breaker 300 is made flexible by being able to autonomously change the tripping threshold of the circuit breaker. For example, in the above example, the threshold of the bidirectional circuit breaker connected to consumer A in the direction toward consumer A is changed from 10 A to 30 A.

[0036] That is, the three-way circuit breaker 300 of this embodiment predicts the power interchange state of the main line from the three current directions and three current magnitudes, and autonomously changes the tripping threshold. This allows for appropriate protection coordination while realizing flexible power interchange that fully utilizes the installed capacity of the system when an imbalance in power (power sources or loads) occurs.

[0037] (Example of a schematic configuration of a three-way semiconductor circuit breaker) Fig. 6 shows an example of the configuration of a three-way circuit breaker 300 in this embodiment. As shown in Fig. 6, the three-way circuit breaker 300 includes a control device 100, a measurement unit 200, circuit breaker units 10, 20, and 30, a power input / output terminal 301, and a communication input / output terminal 302. As shown in a more detailed diagram described later, the control device 100 includes a communication unit 110, a calculation unit 120, a control unit 130, and a clock unit 140. Note that the control device 100 may be located outside the three-way circuit breaker 300.

[0038] The circuit breakers 10 and 20 provided on the main line are unidirectional circuit breakers, and the circuit breaker 30 provided on the branch line is a bidirectional circuit breaker. These circuit breakers each perform current interruption.

[0039] The measuring unit 200 measures the direction and magnitude of the current flowing through each interrupter. An image of a CT (Current Transformer) is shown in FIG.

[0040] When the direction of the current is a predetermined direction and the magnitude of the current exceeds a cutoff threshold, the control unit 130 executes control to open the corresponding cutoff unit. Note that opening the cutoff unit may also be referred to as cutting off the current.

[0041] More specifically, the calculation unit 120 performs calculations for determining the state, and the control unit 130 controls the interrupter unit based on the determination result by the calculation unit 120 .

[0042] The clock unit 140 has a function of synchronizing time with a high-precision clock or a JST clock, etc. The clock unit 140 enables the timing of changing the tripping threshold (which may also be called a setting value) to be synchronized with other tripping units without the tripping units directly communicating with each other. The "tripping units" may be between multiple tripping units within the three-way circuit breaker 300, or may be between multiple tripping units between multiple three-way circuit breakers 300.

[0043] As mentioned above, it is assumed that the interrupting units 10 and 20 on the main line are one-way interrupting units and have a constant interrupting threshold. However, fine adjustments can be made manually or remotely. In the example of Figure 6, the interrupting threshold of the interrupting units 10 and 20 is set to 30A.

[0044] The two blocking thresholds of the bidirectional blocking unit 30 provided on the branch line can be remotely changed or manually adjusted. In the example of Fig. 6, the blocking thresholds of the blocking unit 30 are set to 30A in each direction.

[0045] The communication unit 110 can output information indicating the state of the three-way circuit breaker 300. The communication unit 110 may also be used to change the tripping threshold value or to update software.

[0046] By using the three-way circuit breaker 300 according to this embodiment, it is possible to achieve appropriate protection coordination in the power supply system, and also to flexibly interchange power to fully utilize the installed capacity of the system when an imbalance in power (power source or load) occurs.

[0047] Additionally, each three-way circuit breaker can operate autonomously without communicating with other three-way circuit breakers connected to the mains.

[0048] (Example of Operation of Three-Way Circuit Breaker 300) An example of operation relating to state detection and the like in the three-way circuit breaker 300 will be described below. Here, the description will be made using a simplified diagram shown as "(b) Diagram showing state" on the right side of FIG.

[0049] 7, the upper left part of the inverted triangle in the "(b) state diagram" shows the threshold direction in the interrupter unit 10, and the lower part shows the direction of the current in the interrupter unit 10. Similarly, the upper right part of the inverted triangle corresponds to the interrupter unit 20, and the lower part of the inverted triangle corresponds to the interrupter unit 30.

[0050] 8 to 11, an example of state detection based on the direction of current, which is performed by the control device 100 that monitors the current of each breaker in the three-way breaker 300, will be described.

[0051] State 1 shown in Figure 8 is a state in which all currents in the three interrupter units are flowing toward the branch point. When the control device 100 detects State 1, it determines that an internal short circuit has occurred and interrupts the currents in all the interrupter units. In other words, State 1 corresponds to an "internal short circuit."

[0052] State 2 is a state in which the current of the circuit breaker 30 flows downstream (toward the consumer), and the currents of the other circuit breakers 10 and 20 flow toward the branch point. This also includes a case in which one of the circuit breakers 10 and 20 has no current. When the control device 100 detects state 2, it determines that there is a load at the most downstream position. In other words, it determines that a load is connected to the circuit breaker 30 via a branch line. In other words, state 2 corresponds to a "most downstream load."

[0053] State 3 is a state in which the current direction in the breaker unit 30 is upward, and the current direction in the breakers 10 and 20 is rightward. When the control device 100 detects state 3, it determines that a power source in the middle of the current flowing in the rightward direction on the main line is connected to the breaker unit 30. In other words, state 3 corresponds to a "rightward mid-way power source."

[0054] State 4 is a state in which the current direction of the breaker unit 30 is downward, and the current direction of the breakers 10 and 20 is rightward. When the control device 100 detects State 4, it determines that a load is connected to the breaker unit 30 in the middle of the current flowing in the rightward direction on the main line. In other words, State 4 corresponds to a "rightward mid-load."

[0055] State 5 shown in Figure 9 is a state where the current direction in the breaker unit 30 is upward, and the current direction in the breakers 10 and 20 is leftward. When the control device 100 detects state 5, it determines that a power source is connected to the breaker unit 30 in the middle of the current flowing leftward on the main line. In other words, state 5 corresponds to a "leftward midway power source." For convenience of description, the following description will use only notations such as "leftward midway power source" as appropriate.

[0056] State 6 is a state in which the current direction of the circuit breaker 30 is downward and the current direction of the circuit breakers 10 and 20 is rightward. When the control device 100 detects State 6, it determines that the current state is a "leftward intermediate load."

[0057] State 7 is a state in which the current direction of the interrupter 30 is upward, and the current directions of the interrupters 10 and 20 are outward relative to the branch point. When the control device 100 detects State 7, it determines that the current state is the "most upstream power source."

[0058] State 8 is a state in which the current direction in the interrupter 30 is downward and the current directions in the interrupters 10 and 20 are outward relative to the branch point. When the control device 100 detects state 8, it determines that a "detection error" has occurred.

[0059] 10 is a state in which there is no current in the interrupter 30 and the currents in the interrupters 10 and 20 are flowing toward the branch point. When the control device 100 detects state 9, it determines that an "internal short circuit" has occurred and interrupts the current in all the interrupters.

[0060] State 10 is a state in which there is no current in the breaker unit 30 and the current direction in the breakers 10 and 20 is to the right. When the control device 100 detects state 10, it determines that the current state is "no load on the way to the right."

[0061] 11 is a state in which there is no current in the circuit breaker 30 and the current direction in the circuit breakers 10 and 20 is to the left. When the control device 100 detects state 11, it determines that the current state is "no load on the way to the left."

[0062] State 12 is a state in which there is no current in the interrupter 30 and the currents in the interrupters 10 and 20 flow outward from the branch point. When the control device 100 detects state 12, it determines that a "detection error" has occurred.

[0063] State 13 is a state in which there is no current in the interrupter units 10, 20, and 30. When the control device 100 detects state 13, it determines that there is "no current."

[0064] (Example of Changing the Cutoff Threshold) Next, an example of changing the cutoff threshold depending on the magnitude of the current will be described for states 1 to 13. First, an example of the flow of operation will be described.

[0065] The measurement unit 200 in the three-way circuit breaker 300 measures the current flowing through each of the three circuit breaker units 10 , 20 , and 30 .

[0066] The control device 100 communicates with the bidirectional DC / DC converter connected to the branch line and acquires the converter's status (power supply available, power reception available). If the control device 100 determines that the conditions are met, it executes control to raise the threshold value in stages (for example, in 5 A increments) for a certain period of time. If the control device 100 detects that the current has dropped to a specified value, it executes control to lower the threshold value. Methods for raising and lowering the threshold value will be described later.

[0067] Examples of states 1 to 13 will be described below with reference to Figures 12 to 15. Note that the values ​​shown in Figures 12 to 15 are examples. Also, the thresholds changed by the cutoff unit 30 in the illustrated current directions for each state will be described below.

[0068] As shown in Fig. 12, in state 1, the control device 100 cuts off the current in all interrupter units. In states 2 to 4, when the control device 100 detects that the current in the interrupter unit 30 has reached 10 A, it raises the threshold value in the interrupter unit 30 from 10 A to 15 A. As shown in Fig. 13, in states 5 to 7, when the control device 100 detects that the current in the interrupter unit 30 has reached 10 A, it raises the threshold value in the interrupter unit 30 from 10 A to 15 A.

[0069] In state 9 in Fig. 14, all breakers are broken. In state 10 and state 11 in Fig. 15, when the control device 100 receives an output signal from the DC / DC converter (for example, a signal indicating power transmission from a consumer or a signal indicating power reception at a consumer), it resets the threshold corresponding to the direction of the current to 5 A and closes the circuit in that direction. "Closing the circuit" means allowing current to flow.

[0070] In state 13, when the control device 100 receives a power transmission signal or a power reception signal from the DC / DC converter, it resets the threshold value in the breaker 30 to 5 A and closes the circuit.

[0071] In addition, when the control device 100 detects that a current is flowing based on the current measurement results by the measurement unit 200, without using the output signal from the DC / DC converter, it may reset the threshold value for the interrupter unit 30 and control the closing of the circuit.

[0072] (Equation for Determining the Cut-Off Threshold) Next, the calculation method for determining the cut-off threshold will be described in more detail.

[0073] <When Increasing the Trip Threshold> When the current flowing through the branch line-side tripping unit 30 has reached the trip threshold (upper limit) and the trip threshold needs to be increased, the control device 100 determines the trip threshold using the following equation (1). That is, the trip threshold is increased within a range equal to or less than the value of the right-hand side of the following equation.

[0074] I threshold ≦(I t_main -I m_main ) / (N junction -N min ) (1) In the above formula, I threshold is the cutoff threshold to be set, and I t_main is the main line cutoff threshold, and I m_main is the maximum current value flowing in the mains, and N junction is the number of branch points, and N min is the minimum value of the current input / output point.

[0075] A specific example will be described using the three-way circuit breaker 300 connected to consumer B in the power supply system shown in FIG. 3 as an example. If the interruption threshold of each interrupter on the trunk line in the three-way circuit breaker 300 is 30 A, then I t_main = 30 A. In addition, among the currents on the main line measured by the three-way circuit breaker 300, if the current flowing into the three-way circuit breaker 300 is 10 A and the current flowing out is 20 A, the maximum of these is 20 A, so I m_main = 20 A. In addition, since there are three branch points in the power supply system of FIG. junction In the power supply system of FIG. 3, current is output from any of the consumers and current is input to any of the consumers, so the minimum value of the current input / output points is 2. Therefore, N min = 2. In this case, I threshold≦(30-20) / (3-2)=10A.

[0076] Furthermore, the cutoff threshold when increasing the threshold in states 3, 4, 5, and 6 can be calculated, for example, by the following formula.

[0077] Shutdown threshold≦(shutdown threshold of main line (e.g., 30 A) − maximum current value flowing in the main line (e.g., 20 A or less)) / (number of branch points (e.g., 4) − minimum value of current input / output points (e.g., 2)) After determining the shutdown threshold using the above formula, the control device 100 transmits information about the set shutdown threshold to the DC / DC converter.

[0078] The cutoff threshold when the circuit is closed in state 10 or state 11 can also be calculated using the following formula, for example.

[0079] Shutdown threshold = (shutdown threshold of main line (e.g., 30 A) - maximum current value flowing in the main line (e.g., 20 A or less) / (number of branch points (e.g., 4) - minimum value of current input / output points (e.g., 2)) After determining the shutdown threshold using the above formula, the control device 100 transmits information about the set shutdown threshold to the DC / DC converter.

[0080] <When Lowering the Tripping Threshold> In this embodiment, the tripping threshold can be set in stages. When the control device 100 detects that the current is lower than a tripping threshold that is lower than the initial setting (current setting) of the tripping threshold of the branch line-side tripping unit 30, it sets the tripping threshold to the value immediately above the current.

[0081] For example, suppose that the settable values ​​of the shutoff threshold are 5 A, 10 A, 15 A, 20 A, 25 A, and 30 A, and the current shutoff threshold is 20 A and the actual current flowing is 11 A. In this case, the shutoff threshold is set to 15 A, which is the shutoff threshold immediately above 11 A.

[0082] Fig. 16 is a diagram showing another example. In the example of Fig. 16, the current shut-off threshold is 30 A, and the detected current value is 18 A. In this case, the shut-off threshold is set to 20 A, which is the shut-off threshold immediately above 18 A.

[0083] (Detailed Configuration Example of Three-Way Circuit Breaker 300) Next, a more detailed configuration example of the three-way circuit breaker 300 will be described with reference to Fig. 17. Fig. 17 is a diagram showing an example of the internal circuit of the three-way circuit breaker 300. In Fig. 17, the circuit breakers are marked with the symbols (a), (b), and (c) for the purpose of explaining examples of setting values, which will be described later.

[0084] 17 shows an example in which the three-way circuit breaker 300 is realized using semiconductor elements (e.g., MOSFETs), but this is just one example. The three-way circuit breaker 300 can also be realized using functional units other than semiconductor elements. For example, the three-way circuit breaker 300 can be realized by combining a relay or an electromagnetic contactor with a current detection unit. For example, a Hall element or a shunt resistor can be used as the current detection unit.

[0085] 17 shows an example in which a unidirectional interrupter is used as the interrupter 30. As will be described later, it is possible to use a unidirectional interrupter as well as a bidirectional interrupter as the interrupter 30. Also, all three interrupters 10 to 30 may be bidirectional interrupters.

[0086] Furthermore, the communication line may be, for example, a metal wire, an optical cable, or Wi-Fi (registered trademark).

[0087] As shown in FIG. 17 , the three-way circuit breaker 300 includes a circuit breaker unit 10 (a), a circuit breaker unit 20 (b), a circuit breaker unit 30 (c), a control device 100 , and a measurement unit 200 .

[0088] The interrupter 10(a) is connected to a main line extending in the (a) direction, the interrupter 20(b) is connected to a main line extending in the (b) direction, and the interrupter 30(c) is connected to a branch line extending in the (c) direction.

[0089] Each cutoff unit includes a semiconductor element (e.g., MOSFET), a capacitor, and a diode. Each of A to F in Fig. 17 contains a capacitor or a diode. Specifically, for example, A, D, and F contain diodes, and B, C, and E contain capacitors. Note that the three parts shown as B, C, and E may be unified into one part.

[0090] 17, the measurement unit 200 includes a plurality of current sensors. Each current sensor measures the current flowing through the positive and negative poles, and the current value is measured by the measurement unit 200. The measurement unit 200 may be provided outside the interrupter unit.

[0091] The control device 100 has a communication unit 110, a calculation unit 120, a control unit 130, and a clock unit 140. The calculation unit 120 determines the setting value of each breaker unit based on the direction of the current corresponding to the current value output from the measurement unit 200. The calculation unit 120 also compares the current value with the setting value, and sends a signal to the control unit 130 when the current value is greater than the setting value. The function of the clock unit 140 is as described above.

[0092] The control unit 130 controls the ON / OFF of each cutoff unit based on the calculation result of the calculation unit 120 .

[0093] Fig. 18 shows an example of the setting value of each breaker unit determined by the calculation unit 120. As shown in Fig. 18, for example, if the direction of the current in breaker unit 10(A) is direction (a), the calculation unit 120 determines the setting value of breaker unit 10(A) to be 30A.

[0094] In the example of Figure 18, when current flows in the (a) direction in interrupter unit 10 (a), the circuit of interrupter unit 10 is opened (the current is interrupted) when the current value is 30 A or more. When current flows in the (b) direction in interrupter unit 20 (b), the circuit of interrupter unit 20 is opened when the current value is 10 A or more. When current flows in the (c) direction in interrupter unit 30 (c), the circuit of interrupter unit 30 is opened when the current value is 30 A or more.

[0095] In this embodiment, the three-way circuit breaker 300 is a single package formed by combining (linking) three circuit breaker units 10, 20, and 30. However, the three-way circuit breaker 300 is not limited to being configured as a single package.

[0096] (Processing Flow) The processing flow of the three-way circuit breaker 300 will be described with reference to the flowchart in Fig. 19. As shown in Fig. 19, the flow is divided into phases 0 to 3. Phase 0 has only S1 (step 1), phase 1 has S2 to S9, phase 2 has S10 to S17, and phase 3 has S18 to S23. Note that each three-way circuit breaker 300 is equipped with a clock unit 140, so that the phases can be synchronized among multiple three-way circuit breakers 300.

[0097] In this flow, the three-way circuit breaker 300 communicates with a bidirectional DC / DC converter provided at the consumer. Note that, when a bidirectional circuit breaker is used as the circuit breaker 30, communication with the bidirectional DC / DC converter may not be performed.

[0098] <Phase 0: S1> In S1, basic data is input to the three-way circuit breaker 300 (specifically, the control device 100). Specifically, for example, the following data is input.

[0099] Setting value 1: interruption threshold (initial value) when current flows in the main line (direction (a)) Setting value 2: interruption threshold (initial value) when current flows in the main line (direction (b)) Setting value 3: interruption threshold (initial value) when current flows in the branch line Also, in S1, the control device 100 synchronizes the time of each interrupter with a JST clock or the like so that the timing of each phase matches between the interrupters. Also, in S1, the time of each phase is specified to the control device 100.

[0100] <Phase 1: S2 to S9> In S2, the measurement unit 200 performs current measurement. Specifically, the measurement unit 200 measures the direction and magnitude of the current passing through each interrupter. The control device 100 acquires the measurement results.

[0101] In S3, the control device 100 communicates with the connected bidirectional DC / DC converter and acquires the power supply status of the DC / DC converter. If the control device 100 detects an abnormality (Yes in S4), it issues an error notification and ends the processing (S8, S9).

[0102] If no abnormality is found (No in S4), the control device 100 determines in S5 whether the current has fallen below a tripping threshold that is lower than the initial setting of the tripping threshold in the branch line-side tripping unit 30. If the answer is No, the process proceeds to S7, and if the answer is Yes, the process proceeds to S6. Note that if the current in the tripping unit 30 is flowing downward, the tripping threshold is a downward threshold, and if the current is flowing upward, the tripping threshold is an upward threshold.

[0103] In S6, the control device 100 lowers the interruption threshold of the interruption unit 30 or opens the interruption unit 30 using the method described above.

[0104] The processing of Phase 1 is carried out until the specified time has elapsed. If the specified time has elapsed in S7, the processing proceeds to Phase 2.

[0105] <Phase 2: S10 to S17> In S10, the measurement unit 200 performs current measurement. Specifically, the measurement unit 200 measures the direction and magnitude of the current passing through each interrupter. The control device 100 acquires the measurement results.

[0106] In S11, the control device 100 communicates with the connected bidirectional DC / DC converter and acquires the power supply status of the DC / DC converter. If the control device 100 detects an abnormality (Yes in S12), it issues an error notification and ends the process (S16, S17).

[0107] If no abnormality is detected (No in S12), the control device 100 determines in S13 whether the current flowing through the branch line-side breaker 30 has reached the break threshold (upper limit). If the answer is No, the process proceeds to S15, and if the answer is Yes, the process proceeds to S14.

[0108] In S14, the control device 100 increases the interruption threshold of the interruption unit 30 or closes the interruption unit 30 using the method described above. The processing of Phase 2 is performed until the specified time has elapsed. In S15, if the specified time has elapsed, the processing proceeds to Phase 3.

[0109] <Phase 3: S18 to S23> In S18, the measurement unit 200 performs current measurement. Specifically, the measurement unit 200 measures the direction and magnitude of the current passing through each interrupter. The control device 100 acquires the measurement results.

[0110] In S19, the control device 100 communicates with the connected bidirectional DC / DC converter and acquires the power supply status of the DC / DC converter. If the control device 100 detects an abnormality (Yes in S20), it issues an error notification and ends the process (S21, S22).

[0111] The process of Phase 3 is carried out until the specified time has elapsed. If no abnormality is detected (No in S20), the process returns to Phase 1 when the specified time has elapsed in S23.

[0112] (Example of Operation) The operations of the above-described flow can be summarized as shown in Fig. 20. A specific example of the operations related to the above-described phases will be described.

[0113] First, an example of operation when the tripping threshold is increased will be described with reference to Figures 21 and 22. As shown in Figures 21 and 22, the power supply system in this example of operation is a loop-type wiring power supply system, in which consumers A to D are each connected to a three-way circuit breaker 300 by a branch line. Each three-way circuit breaker has a bidirectional circuit breaker 30 on the branch line side and two one-way circuit breakers 10 and 20 on the trunk line. Each consumer also has a bidirectional DC / DC converter that connects the building to the branch line.

[0114] 21 and 22 show the tripping threshold for each tripping unit. Also shown are the power transmission and reception states of each customer. Fig. 21 shows the state during Phase 1, and Fig. 22 shows the state during Phase 2.

[0115] In the state of phase 1 shown in Figure 21, state 10, 11, or 13 is detected in each of the three-way circuit breaker connected to consumer B and the three-way circuit breaker 300 connected to consumer C, and the circuit breaker 30 is opened and a signal to stop power supply is sent to the DC / DC converter.

[0116] 22 , the three-way circuit breaker 300 connected to consumer A detects state 2. The three-way circuit breaker 300 changes the upper limit (interruption threshold) of the current flowing to the DC / DC converter in the interrupter unit 30 from 10 A to 15 A, and raises the upper limit of the power received by the DC / DC converter (overcurrent protection threshold) to 15 A.

[0117] Furthermore, the three-way circuit breaker 300 connected to consumer D detects state 7. The three-way circuit breaker 300 changes the upper limit (interruption threshold) of the current flowing toward the main line in the interrupter 30 from 10 A to 15 A, and raises the upper limit of the transmission power (overcurrent protection threshold) of the DC / DC converter to 15 A.

[0118] Time has passed since the state in Figure 22. An example of operation when the cutoff threshold is lowered or the circuit is closed will be described with reference to Figures 23 and 24. Figure 23 shows the state during Phase 1, and Figure 24 shows the state during Phase 2.

[0119] In the state of phase 1 shown in Figure 23, state 10, 11, or 13 is detected in each of the three-way circuit breaker 300 connected to consumer A and the three-way circuit breaker 300 connected to consumer D, and the circuit breaker 30 is opened and a signal to stop power supply is sent to the DC / DC converter.

[0120] 24 , the three-way circuit breaker 300 connected to consumer B detects state 10, 11, or 13. When the three-way circuit breaker 300 receives a power transmission signal from the DC / DC converter, it resets the upper limit of the current in the direction toward the main line in the circuit breaker 30 to, for example, 10 A, and closes the circuit breaker 30.

[0121] Furthermore, the three-way circuit breaker 300 connected to consumer C detects state 10, 11, or 13. For example, when the three-way circuit breaker 300 receives a power transmission signal from the DC / DC converter, it resets the upper limit of the current in the direction toward the main line in the circuit breaker 30 to 10 A and closes the circuit breaker 30.

[0122] (Flow from Measurement to Control) Here, a specific example of the flow from measurement to control in the three-way circuit breaker 300 will be described with reference to FIG.

[0123] In S1000, the measurement unit 200 measures the current in each interrupter unit. In S2000, the calculation unit 120 determines whether or not "the set interruption threshold value<the actual current value" in each interrupter unit.

[0124] If the "set cutoff threshold value<actual current value" for a certain cutoff unit, in S3000, the control unit 130 applies a voltage to the gate of the semiconductor element of that cutoff unit. In S4000, the application of the voltage to the gate activates the semiconductor element, thereby cutting off the current.

[0125] (Example 1 of Power Supply System) As Example 1 of the power supply system, FIG. 26 shows an example of a loop wiring type power supply system in which a three-way circuit breaker 300 according to this embodiment is inserted. In the example shown in FIG. 26, three-way circuit breakers 300-1 to 300-4 are provided on a main line, which is a loop wiring. Each three-way circuit breaker 300 has a configuration including three unidirectional circuit breakers. Each three-way circuit breaker 300 is connected to a consumer via a branch line. Having three unidirectional circuit breakers is an example, and as explained above, the circuit breaker 30 may be a bidirectional circuit breaker, or each of the three circuit breakers may be a bidirectional circuit breaker.

[0126] (Power Supply System Example 2) As power supply system example 2, FIG. 27 shows an example of a bus wiring type power supply system in which a three-way circuit breaker 300 according to this embodiment is inserted. In the example shown in FIG. 27, three-way circuit breakers 300-1 to 300-4 are provided on a trunk line, which is a bus wiring. Each three-way circuit breaker 300 has a configuration including three unidirectional circuit breakers. Each three-way circuit breaker is connected to a consumer via a branch line. Having three unidirectional circuit breakers is an example, and as explained above, circuit breaker 30 may be a bidirectional circuit breaker, or each of the three circuit breakers may be a bidirectional circuit breaker.

[0127] (Variation 1) In the basic example, the circuit breakers 10 and 20 of the three circuit breakers 10, 20, and 30 of the three-way circuit breaker 300 are unidirectional circuit breakers, and the circuit breaker 30 connected to the branch line is a bidirectional circuit breaker. In this configuration, the current from the consumer can be controlled by the three-way circuit breaker 300 alone.

[0128] As already explained, the three-way circuit breaker 300 in this embodiment is not limited to the above example, and the circuit breaker 30 may be a unidirectional circuit breaker, as shown in Fig. 28 . In this case, as shown in Fig. 28 , a bidirectional DC / DC converter installed at a consumer site and the three-way circuit breaker 300 are connected by communication lines and control lines to link the two. This makes it possible to limit the output current from the consumer site. In other words, the bidirectional DC / DC converter plays the role of the upward-facing unidirectional circuit breaker in the bidirectional circuit breaker 30 of the basic example.

[0129] In this example, the communication unit 110 is used not only to output the status, change the cutoff threshold, and perform software updates, but also to communicate with the bidirectional DC / DC converter connected to the branch line and control the input and output of the converter.

[0130] (Modification 2) As described above, in the basic example, of the three interrupting units 10, 20, 30 of the three-way circuit breaker 300, the interrupting units 10, 20 are unidirectional interrupting units, and the interrupting unit 30 connected to the branch line is a bidirectional interrupting unit.

[0131] The three-way circuit breaker 300 in this embodiment is not limited to the above example, and each of the circuit breakers 10, 20, and 30 may be a bidirectional circuit breaker, as shown in Fig. 29. In this case, the three-way circuit breaker 300 may not be connected to the bidirectional DC / DC converter.

[0132] (Operation Example 1) When a bidirectional cutoff unit is used as a cutoff unit on a branch line as in the basic example, an operation example 1 relating to the bidirectional cutoff unit will be described with reference to FIG.

[0133] In operation example 1, as shown in Fig. 30, there are consumer A and consumer B connected by a power line, and bidirectional interrupter 30-1 and bidirectional interrupter 30-2 are located between consumer A and consumer B. Fig. 30(a) shows a case where current due to a short circuit flows in a direction from consumer A to consumer B (referred to as direction (a)), and Fig. 30(b) shows a case where current due to a short circuit flows in a direction from consumer B to consumer A (referred to as direction (b)).

[0134] 30, for bidirectional cutoff unit 30-1, a setting value for direction (a) is set to 12A and a setting value for direction (b) is set to 6A. For bidirectional cutoff unit 30-2, a setting value for direction (a) is set to 6A and a setting value for direction (b) is set to 12A.

[0135] 30(a), a short circuit occurs on the side of consumer B, causing a large current to flow in direction (a). Bidirectional circuit breaker 30-2, which has a smaller set value corresponding to direction (a), operates before bidirectional circuit breaker 30-1, and can therefore quickly interrupt the current on the side closer to the short circuit point.

[0136] In the case of Figure 30(b), a short circuit occurs on the customer (a) side, generating a large current in direction (b). Bidirectional circuit breaker 30-1, which has a smaller set value corresponding to direction (b), operates before bidirectional circuit breaker 30-2, so it can quickly interrupt the current on the side closer to the short circuit point.

[0137] (Operation Example 2) Next, operation example 2 in the basic example will be described with reference to Fig. 31. In operation example 2, as shown in Fig. 31, there are consumer A and consumer B connected by a power line, and between consumer A and consumer B there are bidirectional interrupter 30-1, unidirectional interrupters 10 and 20(1) (two unidirectional interrupters), unidirectional interrupters 10 and 20(2) (two unidirectional interrupters), and bidirectional interrupter 30-2.

[0138] Figure 31(a) shows a case where current due to a short circuit flows in a direction from consumer A to consumer B (direction (a)), and Figure 31(b) shows a case where current due to a short circuit flows in a direction from consumer B to consumer A (direction (b)).

[0139] As shown in FIG. 31, the setting of the set values ​​for the bidirectional cutoff unit 30-1 and the bidirectional cutoff unit 30-2 is the same as in the case of the operation example 1 (FIG. 30).

[0140] For the "one-way interrupter 10, 20(1)," a setting value for direction (a) is set to 10A, and a setting value for direction (b) is set to 8A. Also, for the "one-way interrupter 10, 20(2)," a setting value for direction (a) is set to 8A, and a setting value for direction (b) is set to 10A.

[0141] 31(a), a short circuit occurs on the side of consumer B, causing a large current to flow in the direction (a). The bidirectional circuit breaker 30-2, which has the smallest set value corresponding to the direction (a), operates before the other circuit breakers, and can therefore quickly interrupt the current on the side closest to the short circuit point.

[0142] 31(b), a short circuit occurs on the side of consumer A, causing a large current to flow in direction (b). Bidirectional circuit breaker 30-1, which has the smallest set value corresponding to direction (b), operates before the other circuit breakers, and can therefore quickly interrupt the current on the side closest to the short circuit point.

[0143] As explained using Figures 30 and 31, by appropriately setting a plurality of setting values ​​in a plurality of circuit breakers, it is possible to create a larger number of protection coordination sections.

[0144] (Example 1: Specific Example of Power Supply System) Next, a more specific example of a power supply system will be described as Example 1. Fig. 32 shows an example of an outdoor DC power supply system that incorporates a three-way circuit breaker 300 according to this embodiment. The three-way circuit breaker 300 of the example shown in Fig. 32 includes three one-way circuit breakers.

[0145] This outdoor DC power supply system includes consumers A to C, each equipped with a device including a bidirectional DC / DC converter. In this example, each consumer is connected to a three-way circuit breaker 300 by bus wiring.

[0146] (Example 2) Next, Example 2 will be described with reference to Figures 33 and 34. Example 2 is an example in which the set value is a current threshold value. Note that, in Examples 2 and 3, an example in which the breaker unit 30 is a unidirectional breaker is shown, but even if the breaker unit 30 is a bidirectional breaker, the content of the operation described below is basically the same as when the breaker unit 30 is a unidirectional breaker. When the breaker unit 30 is a bidirectional breaker, control when current is transmitted from a consumer can also be performed using the breaker unit 30.

[0147] As shown in Fig. 33, in Example 2, three-way circuit breakers 300-1 to 300-4 are provided on the main line of the loop wiring, and customers are connected to each of the three-way circuit breakers 300 as shown in Fig. 33. Each of the three circuit breakers in each three-way circuit breaker 300 is a one-way circuit breaker.

[0148] The diagram shows the current direction and the current value as the setting value of each circuit breaker when the current flows in that direction. However, since it is not possible to set an upward setting value (current transmitted from the consumer) for the unidirectional circuit breaker 30 on the branch line to which the consumer is connected, coordination is achieved by setting the setting value using the overcurrent protection (OCP) function of the bidirectional DC / DC converter of the connected consumer.

[0149] Suppose the current flow changes from Fig. 33 to Fig. 34. That is, in the situation shown in Fig. 34, current flows from consumer A to consumer C and consumer D, respectively, and current flows from consumer B to consumer C and consumer D, respectively. In the case of the current flow shown in Fig. 34, the set values ​​are as shown.

[0150] That is, in the second embodiment, the setting value of the one-way circuit breaking unit 30 is 30 A when a current flows toward a consumer, and 40 A when a current flows from a consumer toward the bus (main line). The setting value of each of the one-way circuit breaking units 10 and 20 is 35 A.

[0151] Third Embodiment Next, a third embodiment will be described with reference to Fig. 35 and Fig. 36. The third embodiment is an example in which the setpoint is a delay time.

[0152] As shown in Fig. 35, in Example 3, three-way circuit breakers 300-1 to 300-4 are provided on the main line of the loop wiring, and customers are connected to each of the three-way circuit breakers 300 as shown in Fig. 35. Each of the three circuit breakers in each three-way circuit breaker 300 is a one-way circuit breaker.

[0153] The diagram shows the current direction and the delay time set by each breaker when current flows in that direction. However, since the unidirectional breaker 30 on the branch line to which the customer is connected cannot set a set value for the upward current, coordination is achieved by setting a set value using the overcurrent protection (OCP) function of the connected customer's bidirectional DC / DC converter.

[0154] Suppose the current flow changes from Fig. 35 to Fig. 36. That is, in the situation shown in Fig. 36, current flows from consumer A to consumer C and consumer D, respectively, and current flows from consumer B to consumer C and consumer D, respectively. In the case of the current flow shown in Fig. 36, the set values ​​are as shown.

[0155] That is, in the third embodiment, the one-way circuit breaking unit 30 uses a set value of 0 s when a current flows toward a consumer, and uses a set value of +2 ms when a current flows from a consumer to the main line. The one-way circuit breaking units 10 and 20 use a set value of +1 ms in both directions.

[0156] (Hardware Configuration Example) Any of the control devices 100 described in this embodiment can be realized, for example, by causing a computer to execute a program. This computer may be a physical computer or a virtual machine on the cloud.

[0157] That is, the control device 100 can be realized by using hardware resources such as a CPU and memory built into a computer to execute a program corresponding to the processing performed by the control device 100. The program can be recorded on a computer-readable recording medium (such as a portable memory) and can be saved or distributed. The program can also be provided via a network such as the Internet or email.

[0158] Fig. 37 is a diagram showing an example of the hardware configuration of the computer. The computer in Fig. 37 includes a drive device 1000, an auxiliary storage device 1002, a memory device 1003, a CPU 1004, an interface device 1005, a display device 1006, an input device 1007, an output device 1008, and the like, all of which are interconnected by a bus BS. The computer may further include a GPU.

[0159] The program that realizes the processing on the computer is provided by a recording medium 1001, such as a CD-ROM or a memory card. When the recording medium 1001 storing the program is set in the drive device 1000, the program is installed from the recording medium 1001 to the auxiliary storage device 1002 via the drive device 1000. However, the program does not necessarily have to be installed from the recording medium 1001, but may be downloaded from another computer via a network. The auxiliary storage device 1002 stores the installed program as well as necessary files, data, etc.

[0160] The memory device 1003 reads and stores the program from the auxiliary storage device 1002 when an instruction to start the program is received. The CPU 1004 realizes functions related to the control device 100 in accordance with the program stored in the memory device 1003. The interface device 1005 is used as an interface for connecting to a network, etc. The display device 1006 displays a GUI (Graphical User Interface) or the like according to the program. The input device 1007 is composed of a keyboard, mouse, buttons, a touch panel, etc., and is used to input various operation instructions. The output device 1008 outputs the results of calculations.

[0161] (Summary, Effects, etc. of the Embodiments) As described above, the technology described in the present embodiments enables appropriate protection and coordination in a power supply system. Furthermore, when an imbalance in power (power sources or loads) occurs, flexible power interchange that fully utilizes the installed capacity of the system can be realized.

[0162] The following additional notes are provided regarding the above-described embodiments.

[0163] <Supplementary Notes> (Supplementary Item 1) A device comprising: a first circuit breaker arranged on a first direction side of a power line; a second circuit breaker arranged on a second direction side of the power line; and a third bidirectional circuit breaker arranged on a side of a branch line extending from a branch point of the power line. (Supplementary Item 2) The device described in Supplementary Item 1, wherein the first circuit breaker and the second circuit breaker are each unidirectional circuit breakers including one semiconductor element that performs a circuit breaker operation, and the third bidirectional circuit breaker includes two semiconductor elements that perform a circuit breaker operation. (Supplementary Item 3) The device described in Supplementary Item 1 or 2, wherein the device controls the circuit breaker threshold of the third bidirectional circuit breaker based on measurement results of currents flowing through the first circuit breaker, the second circuit breaker, and the third bidirectional circuit breaker. (Supplementary Item 4) The device according to Supplementary Item 3, wherein the device increases the cutoff threshold when it detects that the value of the current flowing through the third bidirectional cutoff unit has reached a set cutoff threshold, and decreases the cutoff threshold to the value immediately above the current value when it detects that the value of the current flowing through the third bidirectional cutoff unit has fallen below a cutoff threshold that is lower than the set cutoff threshold. (Supplementary Item 5) The device according to any one of Supplementary Items 1 to 4, wherein the device further includes a clock unit synchronized with a highly accurate time.

[0164] Although the present embodiment has been described above, the present invention is not limited to such a specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

[0165] 10 to 30 Breaker section 100 Control device 110 Communication section 120 Calculation section 130 Control section 140 Clock section 200 Measurement section 300 Three-way circuit breaker 301 Power input / output terminal 302 Communication input / output terminal 1000 Drive device 1001 Recording medium 1002 Auxiliary storage device 1003 Memory device 1004 CPU 1005 Interface device 1006 Display device 1007 Input device 1008 Output device

Claims

1. An apparatus comprising: a first blocking portion disposed on a side of the power line in a first direction; a second blocking portion disposed on a side of the power line in a second direction; and a third bidirectional blocking portion disposed on a side of a branch line extending from a branch point in the power line.

2. The apparatus according to claim 1, wherein each of the first blocking portion and the second blocking portion is a unidirectional blocking portion including one semiconductor element that performs a blocking operation, and the third bidirectional blocking portion includes two semiconductor elements that perform a blocking operation.

3. The apparatus according to claim 1, wherein the apparatus controls a blocking threshold value in the third bidirectional blocking portion based on measurement results of currents flowing through each of the first blocking portion, the second blocking portion, and the third bidirectional blocking portion.

4. The apparatus according to claim 3, wherein when detecting that a value of a current flowing through the third bidirectional blocking portion has reached a set blocking threshold value, the apparatus raises the blocking threshold value, and when detecting that the value of the current flowing through the third bidirectional blocking portion has fallen below a lower-stage blocking threshold value than the set blocking threshold value, the apparatus lowers the blocking threshold value to a value immediately higher than the value of the current.

5. The apparatus according to any one of claims 1 to 4, further comprising a clock unit synchronized with a high-precision time.

Images