Device and power supply system

Abstract

This device comprises: a plurality of breaker units; and a capacitor provided at an intersection of the plurality of breaker units.

Description

Apparatus and power supply system

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

[0002] In general, in a power supply system, protective coordination is implemented by appropriately setting the settings of the circuit breaker sensitivity, operating time, etc., so that when an accident occurs, the faulty part is quickly isolated and other healthy circuits are protected (for example, Non-Patent Document 1).

[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, ring-type (also called loop-type) power supply systems have been introduced in various regions. 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 circuit breakers are set to trip equipment in order, starting with the lower-level (load side) equipment, in an electrical system in which an accident occurs, in order to minimize the scope of the power outage.

[0005] Study on Short-Circuit Protection Methods for Bus-Wired Outdoor DC Power Supply Systems (IEEJ National Convention 2023, 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 when discharging and as a lower-level load when charging, the direction and route of current flow in a power supply system with storage batteries connected cannot be uniquely determined.

[0007] Therefore, it has been difficult to achieve protection coordination in a ring-type power supply system connected to a storage battery. Note that this issue is not limited to ring-type power supply systems, and can occur in all power supply systems, regardless of whether or not a storage battery is connected.

[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 including a plurality of interrupting sections and capacitors provided at intersections of the plurality of interrupting sections.

[0010] According to the disclosed technology, a technology is provided that enables appropriate protection coordination in a power supply system.

[0011] FIG. 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 a problem. FIG. 5 is a diagram illustrating a problem. FIG. 6 is a diagram illustrating a problem. FIG. 7 is a diagram illustrating a problem. FIG. 8 is a diagram illustrating a configuration example of a three-way circuit breaker 300. FIG. 9 is a diagram illustrating a method for determining the capacitance of a capacitor. FIG. 10 is a diagram illustrating a method for determining the capacitance of a capacitor. FIG. 11 is a diagram illustrating a basic operation example. FIG. 12 is a diagram illustrating a basic operation example. FIG. 13 is a diagram illustrating a basic operation example. FIG. 14 is a diagram illustrating an example of a loop-wired power supply system. FIG. 15 is a diagram illustrating an example of a bus-wired power supply system. FIG. 16 is a diagram illustrating operation example 1 (when a capacitor is not provided). FIG. 17 is a diagram illustrating operation example 1 (when a capacitor is provided). FIG. 18 is a diagram illustrating operation example 2 (when a capacitor is not provided). FIG. 19 is a diagram illustrating example 2 (when a capacitor is provided). FIG. 20 is a diagram illustrating example 1. FIG. 21 is a diagram illustrating example 2. FIG. 22 is a diagram illustrating example 3. FIG. 23 is a diagram illustrating example 3. FIG. 24 is a diagram illustrating example 4. FIG. 25 is a diagram illustrating example 5. FIG. 10 is a diagram illustrating an example of a bidirectional breaking unit. FIG. 11 is a diagram illustrating an example of the configuration of a three-way circuit breaker 300 in a sixth embodiment. FIG. 12 is a diagram illustrating an example of the operation of the sixth embodiment. FIG. 13 is a diagram illustrating an example of the operation of the sixth embodiment. FIG. 14 is a diagram illustrating an example of the operation of the sixth embodiment. FIG. 15 is a diagram illustrating an example of the detailed configuration of the three-way circuit breaker 300. FIG. 16 is a diagram illustrating an example of the setting values ​​of each breaking unit. FIG. 17 is a diagram illustrating the processing flow of the three-way circuit breaker 300. FIG. 18 is a diagram illustrating an example of the operation. FIG. 19 is a diagram illustrating 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] (About power supply systems) 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] (Example of Overall System Configuration) An example configuration of a power supply system according to this embodiment for solving the above-mentioned problems is shown in Fig. 3. 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. Note that the "three-way circuit breaker 300" may also be referred to as a "device."

[0022] In this embodiment, a fuse, an MCCB, a semiconductor element, an electromagnetic contactor + CT, or the like can be used as the interrupting section that is a component of the three-way circuit breaker 300 .

[0023] Each consumer may have any of a load, a storage battery, a power generation device using renewable energy, an EV (electric vehicle), and the like.

[0024] The three-way circuit breaker 300 of this embodiment includes three circuit breakers, each capable of interrupting currents flowing in two directions. Each circuit breaker can perform a circuit breaker operation based on a set value (e.g., current value, voltage value, time limit (hours), etc.) corresponding to the current direction. In the following description, a current threshold value is mainly used as the set value, as an example.

[0025] As will be described later, the three-way circuit breaker 300 of this embodiment is provided with a capacitor at the intersection of the three circuit breakers, but here we will first explain an example of operation when no capacitor is provided, so that the effect of providing a capacitor can be clearly understood.

[0026] For example, when a current flows from consumer B to consumer A, by setting the threshold value (interruption threshold) of the current in the direction toward consumer A at the interrupter connected to the branch line of consumer A to be smaller than any threshold value in the direction of the current flow at the interrupter on the path of the current, for example, if a short circuit occurs on the branch line connected to consumer A, the current can be quickly interrupted at the interrupter connected to consumer A. Furthermore, if the current flow changes, appropriate cooperative operation can be performed by setting a threshold value according to the changed current.

[0027] (Issues when no capacitor is provided) As described above, in a configuration without a capacitor, if a short circuit occurs in the trunk line of the loop-type wiring, there will be a portion where the threshold difference between the interrupters is reversed, resulting in a lack of coordination within the trunk line. Furthermore, if there is no threshold difference between the interrupters of the trunk line, tailgating will occur.

[0028] The above-mentioned problem will be explained with reference to Figures 4 to 8. In each of the cases shown in Figures 4 to 8, 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 three-way circuit breaker via a branch line. Each figure also shows the direction of current flow and the interruption threshold of each interrupter in that direction.

[0029] 4 to 6, when the shutoff thresholds are coordinated clockwise from consumer A, the magnitude relationship of the shutoff thresholds is "36A>34A>32A>30A." When the shutoff thresholds are coordinated counterclockwise from consumer A, the magnitude relationship of the shutoff thresholds is "36A>34A>32A>30A."

[0030] In the case where thresholds are set so as to provide differences in the circuit breaker thresholds with consumer A as the reference as described above, it is assumed that a short circuit occurs in section (3) as shown in FIG.

[0031] In this case, for clockwise current, the interrupting unit of consumer C, which has the smaller interrupting threshold between consumer C's interrupting threshold (34A) and consumer B's interrupting threshold (32A), will operate. For counterclockwise current, the interrupting unit of consumer D, which has the smaller interrupting threshold between consumer A's interrupting threshold (36A) and consumer D's interrupting threshold (34A), will operate. This allows the interrupting unit closest to the short-circuit point to operate (OFF), achieving short-circuit protection coordination.

[0032] On the other hand, suppose a short circuit occurs in section (1) as shown in Figure 6. In this case, for clockwise current, the interrupting unit of consumer D, which has the smaller interrupting threshold (30A) than consumer A (36A), will operate.

[0033] For counterclockwise current, the circuit breaker of consumer B, which has the smaller tripping threshold of consumer C (32A) and consumer B (30A), will operate. As a result, the circuit breaker closest to the short-circuit point will operate for counterclockwise current, but the closest circuit breaker will not operate for clockwise current, so protection coordination cannot be achieved. In the examples shown in Figures 7 and 8, the tripping thresholds are all the same for both clockwise and counterclockwise currents: 30A = 30A = 30A = 30A.

[0034] As shown in Figure 8, assume that a short circuit occurs in section (3). In this case, the tripping threshold (30A) of consumer C and the tripping threshold (30A) of consumer B are the same for clockwise current, so the tripping units of both consumer C and B will operate. For counterclockwise current, the tripping threshold (30A) of consumer A and the tripping threshold (30A) of consumer D are the same, so the tripping units of both consumer A and D will operate. As a result, circuit breakers other than those closest to the short circuit point will operate for both clockwise and counterclockwise currents, and protection coordination will not be achieved.

[0035] (Configuration Example of Three-Way Circuit Breaker 300 in This Embodiment) In order to solve the problem that protection coordination may not be achieved as described above, the three-way circuit breaker 300 in this embodiment is provided with a capacitor, as described above.

[0036] Fig. 9 shows an example of the configuration of a three-way circuit breaker 300 according to this embodiment. As shown in Fig. 9, the three-way circuit breaker 300 according to this embodiment is a circuit breaker device in which circuit breakers are installed in three directions.

[0037] 9, the three-way circuit breaker 300 includes a communication unit 110, circuit breakers 10 and 20 connected to the trunk line, a circuit breaker 30 connected to the branch line, a capacitor 70, a power input / output terminal 301, and a communication input / output terminal 302. Each circuit breaker is, for example, a fuse, an MCCB, or a bidirectional semiconductor circuit breaker.

[0038] For each interrupting unit, if the magnitude of the current flowing through the interrupting unit exceeds the interrupting threshold for that direction, the power line in that direction will be opened (the current will be interrupted). For example, if a fuse is used as the interrupting unit, the fuse will interrupt the current when it exceeds its fusing characteristic. Also, if an MCCB is used as the interrupting unit, the MCCB will interrupt the current when a specified time has passed since the current exceeded its interrupting characteristic.

[0039] The communication unit 110 outputs the interruption state of each interruption unit. Each of the interruption units 10 to 30 can interrupt a current regardless of the direction of the current.

[0040] Furthermore, at the intersection of the three circuit breakers in three-way circuit breaker 300, capacitor 70 having a capacitance according to the cable impedance between three-way circuit breaker 300 and an adjacent three-way circuit breaker is installed between the positive and negative wires. The "intersection" in the configuration of Figure 9 is the intersection of the power line connecting circuit breaker 10 and circuit breaker 20 and the power line connected to circuit breaker 30.

[0041] By using three-way circuit breaker 300 having the above configuration, priority is given to discharging from capacitor 70, and the largest current flows through the circuit breaker closest to the short-circuit point. Therefore, even if the threshold values ​​of the circuit breakers of all three-way circuit breakers installed on the trunk line of the loop wiring are set to the same value (e.g., 30 A), protection coordination between the three-way circuit breakers can be achieved.

[0042] Similarly to the above, protection coordination can be achieved even if the threshold value of the branch line interrupter is set to be as large as the threshold value of the trunk line interrupter (for example, 30 A).

[0043] (Method of Determining Capacitor Capacity) A method of determining the capacitor capacity will be described with reference to Figures 10 and 11. Figure 10 shows a power supply system in which three-way circuit breakers 300-1 to 300-3 are connected by bus wiring.

[0044] The capacity of the capacitor to be installed in the three-way circuit breaker 300 is set based on the longest (highest impedance) of the lengths (more specifically, impedances) of the three wirings connected to the three-way circuit breaker 300 in question.

[0045] In the example of FIG. 10, the wiring distance (2) is the longest among the wiring distances (1), (2), and (3), so the capacitance of the capacitor is determined in accordance with the wiring distance (2).

[0046] Fig. 11 shows the relationship between wiring distance and capacitor capacity. Fig. 11 shows that the longer the distance of the wiring connected to three-way circuit breaker 300, the larger the capacitor capacity mounted on three-way circuit breaker 300.

[0047] Note that "wiring distance" actually refers to wiring impedance. As the wiring cross-sectional area increases, the wiring impedance decreases, and as the wiring length increases, the wiring impedance increases.

[0048] That is, the capacitance of the capacitor is set based on the impedance of the power line having the largest impedance among the multiple power lines (wiring) connected to the three-way circuit breaker 300 .

[0049] (Basic Operation Example) A basic operation example will be described with reference to Figures 12 to 14. All of the power supply systems shown in Figures 12 to 14 have three-way circuit breakers 300A, 300B provided on the main line. In each three-way circuit breaker, the interruption threshold of each of the three interrupting units in the current direction toward the outside from the three-way circuit breaker is shown. All of the interruption thresholds are 30 A. In addition, each figure shows the direction of the short-circuit current and the short-circuit point.

[0050] 12, a short circuit occurs on the right side of three-way circuit breaker 300B. In this case, the current flowing to the right is a current from upstream of the short circuit current, and a discharge current from capacitor 80, so that only the circuit breaker 50 closest to the short circuit point operates (turns off).

[0051] 13, a short circuit occurs on the left side of three-way circuit breaker 300A. In this case, the current flowing to the left is a current from upstream of the short circuit current, and a discharge current from capacitor 70, so that only the circuit breaker 10 closest to the short circuit point operates (turns off).

[0052] 14, a short circuit occurs near Building B. In this case, the current flowing toward Building B is the current from upstream of the short circuit current, plus the discharge current from capacitor 80, causing only the breaker 60 closest to the short circuit point to operate (turn OFF).

[0053] (Example 1 of Power Supply System) As Example 1 of the power supply system, Fig. 15 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. 15, three-way circuit breakers 300-1 to 300-4 are provided on a main line, which is a loop wiring. As described above, each three-way circuit breaker 300 has a configuration including a capacitor and three breakers. Each three-way circuit breaker 300 is connected to a consumer via a branch line.

[0054] (Example 2 of Power Supply System) As Example 2 of the power supply system, Fig. 16 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. 16, three-way circuit breakers 300-1 to 300-4 are provided on a trunk line, which is a bus wiring. As described above, each three-way circuit breaker 300 has a configuration including a capacitor and three breakers. Each three-way circuit breaker is connected to a consumer via a branch line.

[0055] In order to clearly explain the operation according to this embodiment, an operation example 1 and an operation example 2 will be described below for the cases where a capacitor is not provided and where a capacitor is provided, respectively.

[0056] (Operation Example 1: Case where a capacitor is not provided) First, the case where a capacitor is not provided in Operation Example 1 will be described with reference to FIG.

[0057] In operation example 1 (when no capacitor is provided), as shown in Fig. 17 , there are consumer A and consumer B connected by a power line, and there are breaker units 30A and 30B between consumer A and consumer B. The breaker threshold (setting value) is the same 12A in both directions.

[0058] Figure 17(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 17(b) shows a case where current due to a short circuit flows in a direction from consumer B to consumer A (direction (b)).

[0059] In the case of Figure 17(a), a short circuit occurs on the side of consumer B, causing a large current to flow in the direction (a). Because the setting values ​​(or fusing characteristics, interruption characteristics) of the interrupting units 30A and 30B are the same, both interrupting units operate simultaneously (tailgating).

[0060] In the case of Figure 17(b), a short circuit occurs on the side of consumer A, causing a large current to flow in the direction (b). Because the setting values ​​(or fusing characteristics, interruption characteristics) of the circuit breakers 30A and 30B are the same, both circuit breakers operate simultaneously (tailgating).

[0061] (Operation Example 1: When a Capacitor is Provided) Next, the operation example 1 when a capacitor is provided will be described with reference to FIG.

[0062] In operation example 1 (when a capacitor is provided), as shown in Fig. 18, there are consumer A and consumer B connected by a power line, and there are breaker units 30A and 30B between consumer A and consumer B. The breaker threshold (set value) is the same 12 A in both directions. In addition, a capacitor 70 is provided.

[0063] Figure 18(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 18(b) shows a case where current due to a short circuit flows in a direction from consumer B to consumer A (direction (b)).

[0064] 18(a), a short circuit occurs on the side of consumer B, causing a large current to flow in the direction (a). Although the setting values ​​(or fusing characteristics, interruption characteristics) of the circuit breakers 30A and 30B are the same, the discharge current of the capacitor 70 flows in the direction (a), so the circuit breaker 30B, which is closer to the short circuit point, operates first.

[0065] 18(b), a short circuit occurs on the side of consumer A, causing a large current to flow in the direction (b). Although the setting values ​​(or fusing characteristics, interruption characteristics) of the interrupting units 30A and 30B are the same, the discharge current of the capacitor 70 flows in the direction (b), so the interrupting unit 30A, which is closer to the short circuit point, operates first.

[0066] (Operation Example 2: Case where a capacitor is not provided) Next, the operation example 2 where a capacitor is not provided will be described with reference to FIG.

[0067] In operation example 2 (when no capacitor is provided), as shown in Fig. 19, there are consumer A and consumer B connected by a power line, and there are breaker units 30A, 20A, 10B, and 30B between consumer A and consumer B. The breaker thresholds (setting values) are as shown.

[0068] Figure 19(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 19(b) shows a case where current due to a short circuit flows in a direction from consumer B to consumer A (direction (b)).

[0069] In the case of Figure 19(a), a short circuit occurs on the side of consumer B, causing a large current to flow in the direction (a). Because the setting values ​​(or fusing characteristics, interruption characteristics) of the interrupting units 30A and 30B are the same, both interrupting units operate simultaneously (tailgating).

[0070] In the case of Figure 19(b), a short circuit occurs on the side of consumer A, causing a large current to flow in the direction (b). Because the setting values ​​(or fusing characteristics, interruption characteristics) of the interrupting units 30A and 30B are the same, both interrupting units operate simultaneously (tailgating).

[0071] (Operation Example 2: When a Capacitor is Provided) Next, the case of providing a capacitor in Operation Example 2 will be described with reference to Fig. 20. In Operation Example 2 (when a capacitor is provided), as shown in Fig. 20, there are consumer A and consumer B connected by a power line, and there are breaker units 30A, 20A, 10B, 30B and capacitors 70A, 70B between consumer A and consumer B. The breaker thresholds (setting values) are as shown in the figure.

[0072] Figure 20(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 20(b) shows a case where current due to a short circuit flows in a direction from consumer B to consumer A (direction (b)).

[0073] 20(a), a short circuit occurs on the side of consumer B, causing a large current to flow in the direction (a). Although the setting values ​​(or fusing characteristics, interruption characteristics) of circuit breakers 30A and 30B are the same, the discharge current of capacitor 70B flows in the direction (a), so circuit breaker 30B, which is closer to the short circuit point, operates first.

[0074] 20(b), a short circuit occurs on the side of consumer A, causing a large current to flow in the direction (b). Although the setting values ​​(or fusing characteristics, interruption characteristics) of the circuit breakers 30A and 30B are the same, the discharge current of the capacitor 70A flows in the direction (b), so the circuit breaker 30A, which is closer to the short circuit point, operates first.

[0075] A more specific example will be described below as an example.

[0076] (Example 1: Example of a specific power supply system) As Example 1, a more specific example of a power supply system will be described. Fig. 21 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. 21 includes a capacitor and three circuit breakers.

[0077] 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.

[0078] (Example 2) Next, Example 2 will be described with reference to Fig. 22 and Fig. 23. Example 2 is an example in which the set value is a current threshold value.

[0079] As shown in Fig. 22, in the second embodiment, 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. 22. The setting values ​​of all the circuit breakers are the same.

[0080] The diagram shows the direction of the short-circuit current when a short circuit occurs at the location shown, and the current value as the set value of each circuit breaker when current flows in that direction. The set values ​​of all circuit breakers are the same. As shown by the circles in Figure 22, the circuit breaker closest to the short circuit point will operate.

[0081] Suppose the position of the short-circuit point changes from Figure 22 to Figure 23, and the flow of the short-circuit current changes accordingly. That is, in the situation shown in Figure 23, current flows from consumer A to consumer C and consumer D, respectively, and short-circuit current flows from consumer B to consumer C and consumer D, respectively. Even in this case, the circuit breaker located near the short-circuit point will operate.

[0082] Third Embodiment Next, a third embodiment will be described with reference to Fig. 24 and Fig. 25. The third embodiment is an example in which the setpoint is a delay time.

[0083] As shown in Fig. 24, in the third embodiment, 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. 24. The setting values ​​of all the circuit breakers are the same.

[0084] The diagram shows the direction of the short-circuit current when a short circuit occurs at the location shown, and the delay time as the setting value of each circuit breaker when current flows in that direction. The setting values ​​of all circuit breakers are the same. As shown by the circle in Figure 24, the circuit breaker closest to the short circuit point will operate.

[0085] Suppose the position of the short-circuit point changes from Figure 24 to Figure 25, and the flow of the short-circuit current changes accordingly. That is, in the situation shown in Figure 25, current flows from consumer A to consumer C and consumer D, respectively, and short-circuit current flows from consumer B to consumer C and consumer D, respectively. Even in this case, the circuit breaker located near the short-circuit point will operate.

[0086] (Example 4 (another example of circuit breaker configuration)) In the explanation so far, a case has been described in which a three-way circuit breaker 300 is used as a circuit breaker equipped with a capacitor, but the number of directions is not limited to three. In this embodiment, an N-way circuit breaker equipped with a capacitor can be used. N may be 2 or an integer equal to or greater than 4.

[0087] 26 shows an example of the configuration of a four-way circuit breaker 400. As shown in FIG. 26, the four-way circuit breaker 400 includes circuit breakers 10 to 40 and a capacitor 70.

[0088] Furthermore, the four-way circuit breaker 400 is not limited to a device in which four circuit breakers are integrated. As shown in Fig. 27, it may be configured to include individual circuit breakers 10 to 40 and a capacitor 70.

[0089] Fifth Embodiment The three-way circuit breaker 300 of this embodiment may be used for any purpose. For example, it may be used in an internal bus of a ship, an airplane, an automobile, etc. An example of the configuration of a power supply system when used as such an internal bus is shown in FIG. 28 .

[0090] Sixth Embodiment In a sixth embodiment, an example in which a semiconductor element is used as a breaker in a three-way circuit breaker 300 will be described.

[0091] In the sixth embodiment, a one-way cutoff section is used as the cutoff section using a semiconductor element, but a two-way cutoff section may be used instead of the one-way cutoff section.

[0092] <Regarding the unidirectional cutoff unit and bidirectional cutoff unit> Here, examples of a unidirectional cutoff unit and a bidirectional cutoff unit using semiconductor elements will be described. Fig. 29 shows an example of a unidirectional cutoff unit. As shown in Fig. 29, 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.

[0093] An example of a bidirectional cutoff unit is shown in Figure 30. As shown in Figure 30, 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 opposite directions. A and D are, for example, diodes, and B and C are, for example, capacitors.

[0094] 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.

[0095] <Example of a schematic configuration of a three-way circuit breaker 300> Fig. 31 shows an example of the configuration of a three-way circuit breaker 300 in Example 6. As shown in Fig. 31 , the three-way circuit breaker 300 includes a control device 100, a measurement unit 200, circuit breaker units 10, 20, and 30, a capacitor 70, 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, and a control unit 130. The control device 100 may be located outside the three-way circuit breaker 300.

[0096] The measurement 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.

[0097] 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.

[0098] More specifically, the calculation unit 120 performs calculations for the determination, and the control unit 130 controls the cutoff unit based on the determination result by the calculation unit 120 .

[0099] 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.

[0100] In the sixth embodiment, the consumer is provided with a bidirectional DC / DC converter, which is connected to the branch line. The communication unit 110 communicates with the bidirectional DC / DC converter to acquire information from the bidirectional DC / DC converter and control the overcurrent protection function of the bidirectional DC / DC converter. The bidirectional DC / DC converter can perform operations such as cutting off current flowing from the consumer to the main line.

[0101] Each of the three interrupting units 10, 20, and 30 is a unidirectional interrupting unit that interrupts current in one direction. Figure 31 shows an example of the current detection direction and threshold current value for each interrupting unit. In the example shown in Figure 31, all thresholds are the same.

[0102] In the example of Figure 31, circuit breaker 10 is provided between the trunk line extending to the left and the branch point, and circuit breaker 20 is provided between the trunk line extending to the right and the branch point. Circuit breaker 30 is provided between the consumer and the branch point. At the intersection of the three circuit breakers, capacitor 70 is installed between the positive and negative wires.

[0103] The configuration shown in Figure 31 allows three-way circuit breakers to coordinate their protection even if the thresholds of all circuit breakers installed on the main line of the loop wiring are set to the same value (e.g., 30 A). In other words, because discharge from the capacitor takes priority, the largest current flows through the circuit breaker closest to the short-circuit point. Similarly, coordination is possible even if the thresholds of the circuit breakers on the branch lines are set to the same value (e.g., 30 A) as the main line.

[0104] <Example 6: Example of Operation> An example of operation will be described with reference to Figures 32 to 34. All of the power supply systems shown in Figures 32 to 34 show three-way circuit breakers 300A and 300B provided on the main line. In each three-way circuit breaker, the interruption threshold values ​​of the three one-way interrupting units are shown. In addition, each figure shows the direction of the short-circuit current and the short-circuit point.

[0105] 32, a short circuit occurs near capacitor 80 of three-way circuit breaker 300B. In this case, an internal short circuit can be detected by measuring currents in three directions in three-way circuit breaker 300B, and each of circuit breakers 40 to 60 shown in squares can be shut off.

[0106] For example, if the direction of current flowing toward the outside of the three-way circuit breaker 300B is considered to be the positive direction, the three-way circuit breaker 300B can determine that an internal short circuit has occurred if it detects that the sum of the value of the current flowing through the one-way circuit breaker 40, the value of the current flowing through the one-way circuit breaker 50, and the value of the current flowing through the one-way circuit breaker 60 has become a negative value.

[0107] In the case of Fig. 33, a short circuit occurs between three-way circuit breaker 300A and three-way circuit breaker 300B. In this case, if the capacitor capacity is sufficient, it is possible to operate the circuit breaker closest to the short circuit point.

[0108] In the case of Fig. 34, the threshold value of all the circuit breakers is set to the same value of 10 A. In the case of Fig. 34, a short circuit occurs between three-way circuit breaker 300A and three-way circuit breaker 300B. In this case, too, if the capacitor capacity is sufficient, it is possible to operate the circuit breaker closest to the short circuit point.

[0109] As described above, by increasing the number of types of circuit breakers and combining them with capacitors, the range of protection coordination sections can be expanded.

[0110] <Detailed Configuration Example of Three-Way Circuit Breaker 300> Next, a more detailed configuration example of the three-way circuit breaker 300 in Example 6 will be described with reference to Fig. 35. Fig. 35 is a diagram showing an example of the internal circuit of the three-way circuit breaker 300. In Fig. 35, the circuit breakers are marked with symbols (A), (B), and (C) for the purpose of explaining examples of setting values, which will be described later.

[0111] 35 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.

[0112] Furthermore, the communication line may be, for example, a metal wire, an optical cable, or Wi-Fi (registered trademark).

[0113] 35 , 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. In addition, a capacitor 70 is inserted at the intersection of the circuit breaker units 10, 20, and 30.

[0114] 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.

[0115] Each cutoff unit includes a semiconductor element (e.g., MOSFET), a capacitor, and a diode. Each of A to F in Fig. 35 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.

[0116] 35, 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.

[0117] The control device 100 has a communication unit 110, a calculation unit 120, and a control unit 130. 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.

[0118] The control unit 130 controls the ON / OFF of each cutoff unit based on the calculation result of the calculation unit 120 .

[0119] Fig. 36 shows an example of the setting value of each breaker unit determined by the calculation unit 120. As shown in Fig. 36, 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.

[0120] In the example of Figure 36, 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.

[0121] In the sixth embodiment, the three-way circuit breaker 300 is a single package formed by combining (linking) three one-way circuit breaking units 10, 20, and 30. However, the three-way circuit breaker 300 is not limited to being configured as a single package.

[0122] <Processing Flow> A processing flow of the three-way circuit breaker 300 in the sixth embodiment will be described with reference to the flowchart of FIG.

[0123] <S101> In S101, basic data is input to the three-way circuit breaker 300 (specifically, the control device 100). Specifically, for example, the following basic data (1) and (2) are input.

[0124] ) + (setting value of main line circuit breaker 20 (right))} / 2 English: (1) Setting values ​​for the three-way circuit breaker 300 Setting value 1: setting value when current flows in direction (a) Setting value 2: setting value when current flows in direction (b) Setting value 3: setting value when current flows in direction (c) (2) Setting values ​​for overcurrent protection sent to the bidirectional DC / DC converter Setting value 1: setting value for current toward the branch line side Setting value 2: setting value for current toward the customer's premises Specifically, the setting value 1 above is set to a value within the range of the following condition, for example: "Setting value 1 < {(setting value of main line circuit breaker 10 (left)) + (setting value of main line circuit breaker 20 (right))} / 2" The setting value 2 above is set to a value within the range of the following condition: "Setting value 2 < setting value of the branch line circuit breaker" <S102> In S102, the control device 100 (for example, the communication unit 110) communicates with the bidirectional DC / DC converter to acquire information about the bidirectional DC / DC converter. Specifically, the control device 100 acquires status parameters (normal or abnormal), measurement data (current, voltage), setting values ​​(overcurrent threshold, etc.) for the bidirectional DC / DC converter. Based on the acquired information, the control device 100 also confirms that there is no abnormality in the bidirectional DC / DC converter.

[0125] <S103> In S103, the control device 100 changes the settings of the bidirectional DC / DC converter. Specifically, the control device 100 transmits and sets the overcurrent protection (OCP) current values ​​(setting value 1 and setting value 2) to the bidirectional DC / DC converter.

[0126] <S104> In S104, the measurement unit 200 performs current measurement. Specifically, the measurement unit 200 measures the direction and magnitude of the current passing through each interrupter.

[0127] <S105, S106> In S105, if the calculation unit 120 determines that "the value of the current flowing in the (a) direction is greater than the set value 1," the control unit 130 opens the breaker unit 10(A) in S106. In addition, for example, the communication unit 110 outputs an alarm.

[0128] <S107, S108> If the calculation unit 120 determines in S107 that "the value of the current flowing in the (b) direction is greater than the set value 2," the control unit 130 opens the breaker unit 20(b) in S108. In addition, for example, the communication unit 110 outputs an alarm.

[0129] <S109, S110> In S109, if the calculation unit 120 determines that "the value of the current flowing in the (c) direction is greater than the set value 3," the control unit 130 opens the breaker unit 30(c) in S110. In addition, for example, the communication unit 110 outputs an alarm.

[0130] <S111, S112> In S111, the calculation unit 120 calculates "I （ａ） +I （ｂ） +I （ｃ） If it is determined that the value is "0", then in step S112, for example, the communication unit 110 outputs an alarm (detection error). （ａ） is the value of the current flowing in the (a) direction. （ｂ） is the value of the current flowing in the (b) direction. （ｃ） is the value of the current flowing in the (c) direction.

[0131] <S113, S114> In S113, the calculation unit 120 calculates "I （ａ） +I （ｂ） +I （ｃ） If it is determined that the value is "<0", the control unit 130 opens all the interrupters in S114. Also, for example, the communication unit 110 outputs an alarm.

[0132] <Example of 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.

[0133] 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.

[0134] 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.

[0135] (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.

[0136] 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.

[0137] Fig. 39 is a diagram showing an example of the hardware configuration of the computer. The computer in Fig. 39 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.

[0138] 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.

[0139] 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.

[0140] (Summary, Effects, etc. of the Embodiments) As described above, the techniques described in the present embodiments enable appropriate protection coordination in a power supply system.

[0141] The following additional notes are provided regarding the above-described embodiments.

[0142] <Supplementary Notes> (Supplementary Item 1) A device comprising a plurality of circuit breakers, and a capacitor provided at an intersection of the plurality of circuit breakers. (Supplementary Item 2) 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, a third circuit breaker arranged on a side of a branch line extending from a branch point of the power line, and a capacitor provided at an intersection of the first circuit breaker, the second circuit breaker, and the third circuit breaker. (Supplementary Item 3) The device according to Supplementary Item 1 or 2, wherein the capacitance of the capacitor is set based on the impedance of a power line having the largest impedance among a plurality of power lines connected to a plurality of circuit breakers in the device. (Supplementary Item 4) A power supply system comprising a plurality of the devices according to Supplementary Item 1 or 2 on a loop wiring. (Supplementary Item 5) A power supply system comprising a plurality of the devices according to Supplementary Item 1 or 2 on a bus wiring.

[0143] 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.

[0144] 10 to 60 Breaker section 70, 80 Capacitor 100 Control device 110 Communication section 120 Calculation section 130 Control section 200 Measurement section 300 Three-way circuit breaker 301 Power input / output terminal 302 Communication input / output terminal 400 Four-way circuit breaker 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. A device comprising: a plurality of interrupting sections; and a capacitor provided at the intersection of the plurality of interrupting sections.

2. 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; a third circuit breaker arranged on a branch line extending from a branch point of the power line; and a capacitor provided at the intersection of the first circuit breaker, the second circuit breaker, and the third circuit breaker.

3. The device according to claim 1 or 2, wherein the capacitance of the capacitor is set based on the impedance of the power line having the largest impedance among a plurality of power lines connected to a plurality of circuit breakers in the device.

4. A power supply system comprising a plurality of the devices according to claim 1 or 2 on a loop wiring.

5. A power supply system comprising a plurality of the devices according to claim 1 or 2 on a bus line.

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