Circuit protection device and energy system of power conversion device

Abstract

The embodiment of the invention provides a circuit protection device and an energy system of a power conversion device. The circuit protection device comprises a fuse group and a switch unit which are arranged in any conductor wire of a circuit; the fuse group comprises a plurality of fuses which are connected in parallel; the switch unit is used for controlling connection and disconnection between at least one fuse in the fuse group and the conductor wire; and after the fuses communicated with the conductive wire are fused, the switch unit responds to a switch-on control signal sent by the control unit, and at least one unfused fuse in the fuses is communicated with the conductive wire. And the unfused fuse is automatically switched to be communicated with the conductor wire, so that the maintenance cost of the fuse can be reduced to a certain extent.

Description

Technical Field

[0001] The embodiments in this specification relate to the field of electrical engineering, and specifically to an energy system of a circuit protection device and a power conversion device. Background Art

[0002] In the field of electrical engineering, fuses, as an important protective component, can prevent damage to electrical equipment caused by circuit overcurrent or short circuit to a certain extent.

[0003] However, fuses installed in power equipment require a lot of maintenance costs. Specifically, when an overcurrent occurs in the circuit, the conductor in the fuse will melt due to the large amount of heat generated, thereby disconnecting the circuit and cutting off the current. Therefore, before the power equipment resumes operation, a new fuse needs to be manually replaced, which increases maintenance costs and time costs.

[0004] Therefore, there is a technical problem in the prior art that the maintenance cost of the fuse is high. Summary of the invention

[0005] Multiple embodiments in this specification provide an energy system of a circuit protection device and a power conversion device, which can reduce the maintenance cost of fuses to a certain extent.

[0006] One embodiment in the present specification provides a circuit protection device, which includes: a fuse group and a switch unit for being set in any conductive line of the circuit; the fuse group includes a plurality of fuses connected in parallel; the switch unit is used to control the connection and disconnection between at least one fuse in the fuse group and the conductive line; after the fuse connected to the conductive line is blown, the switch unit responds to a connection control signal issued by a control unit to connect at least one unblown fuse among the plurality of fuses to the conductive line.

[0007] In some embodiments, the switch unit includes a plurality of switch elements; the plurality of fuses respectively have a first end connected by a first connection line, and a second end connected by a second connection line; the switch element is arranged between the first ends of two adjacent fuses in the first connection line; and / or the switch element is arranged between the second ends of two adjacent fuses in the second connection line.

[0008] In some embodiments, after the fuse connected to the conductive line is blown, the switch elements in the switch unit directly connected to the blown fuse are closed to connect the unblown fuse connected to the closed switch elements to the conductive line.

[0009] In some embodiments, the first connecting circuit has a first node connected to the conductive line, and the second connecting circuit has a second node connected to the conductive line; when the fuse connected to the conductive line is in a normal state, the switching elements arranged between the fuse and the first node, or between the fuse and the second node are all in a closed state, and the switching elements not between the fuse and the first node, or between the fuse and the second node are in an open state.

[0010] In some embodiments, the circuit protection device further comprises a detection device; after detecting that a fuse connected to the conductive line is blown, the detection device sends a detection signal indicating that the fuse is blown to the control unit.

[0011] An embodiment of the present specification provides a power conversion device, in which the circuit protection device described in any of the above embodiments is provided, and the control unit is a controller of the power conversion device.

[0012] In some embodiments, the circuit protection device is used to be arranged on any bus of a power conversion device; wherein the bus includes a DC bus or an AC bus.

[0013] In some embodiments, the DC bus of the power conversion device includes a DC positive bus and a DC negative bus; the DC positive bus and the DC negative bus are respectively provided with the circuit protection device.

[0014] In some embodiments, the AC bus of the power conversion circuit includes an AC A-phase bus, an AC B-phase bus and an AC C-phase bus; the AC A-phase bus, the AC B-phase bus and the AC C-phase bus are respectively provided with the fuse group.

[0015] In some embodiments, the power conversion device further includes a power supply unit capable of supplying power to the switch unit and the controller when a fuse connected to the conductive line is in a blown state.

[0016] In some embodiments, the controller is used to send a connection control signal to the switch unit to control the connection between the blown fuse and the conductive line after the fuse connected to the conductive line has blown and when a system recovery signal is received.

[0017] An embodiment of the present specification provides an energy system, comprising: a power conversion device as described in any of the above embodiments; an AC side of the power conversion device is used to connect to a power grid.

[0018] In the multiple embodiments provided in this specification, the circuit protection device may include a switch unit, and a fuse group and a switch unit for being set in any conductive line of the circuit. The fuse group may be formed by a plurality of fuses connected in parallel. The switch unit may be used to control the connection or disconnection between the fuses in the fuse group and the conductive line. When the circuit protection device is working normally, some fuses may be controlled by the switch unit to be connected to the conductive line. After the fuse connected to the conductive line is blown, the switch unit may respond to the connection control signal issued by the control unit to connect at least one unblown fuse to the conductive line. Thus, in the multiple embodiments provided in this specification, after the conductive line fails, the circuit protection device may respond to the connection control signal of the control unit to automatically switch the unblown fuse to be connected to the conductive line. This may enable the staff to not manually replace the fuse every time the conductive line fails, reduce the frequency of the staff replacing the fuse, and thus reduce the maintenance cost of the fuse to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0020] Figure 1 A schematic diagram of the structure of a circuit protection device provided for one embodiment of the present specification.

[0021] Figure 2 A topological diagram of a circuit protection device provided for one embodiment of the present specification.

[0022] Figure 3 A topological diagram of a circuit protection device provided for one embodiment of the present specification.

[0023] Figure 4 A schematic diagram of a power conversion device provided with a circuit protection device on a DC bus according to an embodiment of the present specification.

[0024] Figure 5 A schematic diagram of a power conversion device with a DC bus provided with a circuit protection device for post-fault recovery is provided according to an embodiment of the present specification.

[0025] Figure 6 A schematic diagram of a power conversion device provided with a circuit protection device on an AC bus according to an embodiment of the present specification.

[0026] Figure 7A schematic diagram of a power conversion device with an AC bus provided with a circuit protection device for post-fault recovery is provided according to an embodiment of the present specification.

[0027] Figure 8 A schematic diagram of a power conversion device provided for one embodiment of the present specification in which both a DC bus and an AC bus are provided with circuit protection devices.

[0028] Fig. 9 A schematic diagram of post-fault recovery operation of a power conversion device in which both a DC bus and an AC bus are provided with circuit protection devices is provided for one embodiment of the present specification.

[0029] 1. Reference numerals: 10. conductive line; 100. circuit protection device; 110. fuse group; 112. fuse; 120. switch unit; 122. switch element; 130. first connection line; 140. second connection line; 150. detection device; 160. control unit; 170. power supply unit; 180. DC bus; 182. positive DC bus; 184. negative DC bus; 190. AC bus; 192. A-phase bus; 194. B-phase bus; 196. C-phase bus; 200. first node; 210. second node. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0031] In the description of the embodiments of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0032] In order to solve the technical problem of high maintenance cost of fuses, the inventors have conducted a detailed study of the relevant technologies. Specifically, the inventors found that an important reason for the high maintenance cost of fuses is that the fuses used in the relevant technologies need to be replaced by professional technicians after they are blown, which requires high labor costs and long maintenance time.

[0033] Therefore, one of the keys to solving this technical problem is to design an intelligent circuit protection device so that it can automatically recover after the fuse blows, thereby reducing labor costs and maintenance time.

[0034] Although, the recoverable fuse can meet the above requirements to a certain extent. For example, the recoverable fuse in the related art uses the deformation of bimetallic strips with different thermal deformation coefficients to disconnect the circuit. However, the bimetallic strip may have a problem of reduced recovery ability after long-term use, which may cause the sensitivity of the fuse to deteriorate and pose certain safety hazards. Therefore, the use of a disposable fuse (traditional fuse) is still an option that takes into account both performance and safety.

[0035] To this end, the multiple embodiments provided in this specification propose a circuit protection device, a power conversion device and an energy system. The circuit protection device may include a switch unit and a fuse group. The fuse group may include a plurality of fuses connected in parallel. The fuse group and the switch unit may be arranged in the conductive line of the circuit, and the connection or disconnection between the fuse in the fuse group and the conductive line may be controlled by the switch unit. During the operation of the circuit protection device, when the fuse connected to the conductive line is blown, the switch unit can respond to the connection control signal of the control unit to connect at least one unblown fuse to the conductive line, thereby realizing automatic recovery of the circuit after a fault occurs.

[0036] In the multiple embodiments provided in this specification, the fuse can be a disposable fuse, so as to balance performance and safety to a certain extent. In addition, since the fuse group in the multiple embodiments provided in this specification can include multiple fuses, after one of the fuses is blown, the unblown fuse can be automatically connected to the circuit, thereby reducing the maintenance cost of frequent manual replacement of fuses. In addition, after some fuses in the fuse group are blown, when these fuses are manually replaced, the circuit can also be operated through the unblown fuse, so that the process of replacing the fuse and the operation process of the circuit can be carried out at the same time, which can avoid the problem of reduced operating efficiency of the system in which the circuit is located due to the need to stop the circuit operation when replacing the fuse in some cases to a certain extent.

[0037] See also Figure 1 An embodiment of the present specification provides a circuit protection device 100. The circuit protection device 100 can be used to prevent electrical equipment from being damaged due to overcurrent or short circuit faults in the circuit to a certain extent.

[0038] Specifically, the circuit protection device 100 may include a fuse group 110 and a switch unit 120 for being arranged in any conductive line 10 of the circuit. That is, the switch unit 120 and the fuse group 110 of the circuit protection device 100 may be connected in series in any conductive line 10 of the circuit.

[0039] The fuse group 110 may include a plurality of fuses 112 connected in parallel. The plurality of fuses 112 may be connected in parallel. Specifically, each fuse 112 may include a first end and a second end. The first ends of the plurality of fuses 112 may be connected, and the second ends of the plurality of fuses 112 may be connected.

[0040] The switch unit 120 can be used to control the connection and disconnection between at least one fuse 112 in the fuse group 110 and the conductive line 10 in which the fuse group 110 is set. Specifically, the switch unit 120 can be connected to the fuses 112 in the fuse group 110 to control the connection between one or more fuses 112 in the fuse group 110 and the conductive line 10, and control the disconnection between one or more fuses 112 and the conductive line 10.

[0041] During the operation of the circuit protection device 100, at least one fuse 112 may be connected to the conductive line 10 of the circuit, and a current path is formed through the fuse of the fuse 112. When a fault such as an overload current or a short circuit current occurs in the circuit, the fuse of the fuse 112 may melt to cut off the current, thereby preventing damage to the electrical equipment to a certain extent.

[0042] After the fuse 112 is blown, the circuit may stop running. Professional technicians or the control unit that controls the circuit can troubleshoot and eliminate the fault. In addition, after the fault is eliminated, the control unit can send a connection control signal to the switch unit 120. In response to the connection control signal sent by the control unit, the switch unit 120 can connect at least one unblown fuse 112 in the fuse group 110 with the conductive line 10, so that the conductive line 10 and the fuse in the unblown fuse 112 form a new current path, so that the circuit can resume operation. In this way, the maintenance cost of the fuse 112 can be reduced to a certain extent and the operating efficiency of the circuit system can be improved.

[0043] The connection control signal may be used to control the switch unit 120 to connect at least one unblown fuse 112 in the fuse group 110 to the conductive line 10 .

[0044] In some embodiments, the switch unit 120 may include a plurality of switch elements that can be closed or opened independently. For different types of switch elements, the on control signal issued by the control unit may also be different. For example, when the switch element is a semiconductor switch, the on control signal may be an electrical signal applied by the control unit to the control end of the semiconductor switch. Alternatively, when the switch element is a latching solid-state relay, the on control signal may be a pulse signal. The embodiments of this specification are not specifically limited here.

[0045] In some embodiments, the control unit may be a controller disposed inside the circuit protection device 100. Of course, the control unit may also be a controller in a circuit system connected to the circuit protection device 100. The embodiments of this specification are not specifically limited here.

[0046] See also Figure 2 In one embodiment provided in this specification, the switch unit 120 may include a plurality of switch elements 122. A switch element 122 and a fuse 112 may be connected in series. Multiple groups of series-connected switch elements 122 and fuses 112 may be connected in parallel.

[0047] The switch element 122 in the switch unit 120 can be closed or opened under the control of the on control signal of the control unit. For example, when the circuit protection device 100 is arranged in the conductive line 10 of the circuit, and multiple fuses are not blown, the switch element 1221 can be closed, and the switch element 1222, the switch element 1223 to the switch element 122n can be opened. As a result, the parallel branch where the switch element 1221 is located can be connected to the conductive line 10. The conductive line 10 can form a current path through the fuse 1121 connected in series with the switch element 1221. In the case of a fault such as overcurrent or short circuit in the conductive line 10, the fuse 1121 may be blown. After the fault such as overcurrent or short circuit is eliminated, the switch element 1222 can be closed under the control of the on control signal of the control unit, and the switch element 1223 to the switch element 122n can remain open. At this time, the conductive line 10 can form a current path through the fuse 1122 connected in series with the switch element 1222.

[0048] In some cases, each fuse 112 is connected in series with a switch element 122, and the circuit may not operate if the switch unit 120 fails to operate normally. Therefore, in some embodiments, a fuse 112 may be provided in one or more parallel branches without a switch element 122. This allows the circuit to operate normally even if the switch unit 120 fails to operate normally, and the circuit protection device 100 still has a certain ability to prevent the circuit from being damaged by electrical equipment after a fault such as overcurrent or short circuit. In addition, by reducing the switch element 122, the cost of the circuit protection device 100 can also be reduced to a certain extent.

[0049] Please combine Figure 3 In one embodiment provided in the present specification, the switch unit 120 may include a plurality of switch elements 122 that can be closed or opened independently. The plurality of fuses 112 may respectively have first ends connected through a first connection line 130 and second ends connected through a second connection line 140. The switch element 122 may be disposed between the first ends of two adjacent fuses 112 in the first connection line 130.

[0050] In some embodiments, the switch element 122 may also be disposed between the second ends of two adjacent fuses 112 in the second connection line 140. Alternatively, the switch element 122 may be disposed between the first ends of two adjacent fuses 112 in the first connection line 130 and between the second ends of two adjacent fuses 112 in the second connection line 140.

[0051] The first connection line 130 and the second connection line 140 can be used to connect the conductive line 10. For example, any end of the first connection line 130 can be connected to the conductive line 10. The connection point where one end of the first connection line 130 is connected to the conductive line can be used as a first node 200. Any end of the second connection line 140 can also be connected to the conductive line 10, and the end of one end of the second connection line 140 connected to the conductive line can be used as a second node 210.

[0052] In some embodiments, the connection point between the conductive wire 10 and the first connection line 130 may also be located in the middle line segment of the first connection line 130. Alternatively, the connection point between the conductive wire 10 and the second connection line 140 may also be located in the middle line segment of the second connection line 140. This specification does not specifically limit this.

[0053] When the fuse 112 connected to the conductive line 10 is in a normal state, the switch element 122 between the fuse 112 and the first node 200, or between the fuse 112 and the second node 210 is in a closed state, and the switch element 122 not between the fuse 112 and the first node 200, or between the fuse 112 and the second node 210 is in an open state.

[0054] After the fuse 112 connected to the conductive line 10 is blown, controlled by the connection control signal issued by the control unit, the switch elements 122 in the switch unit 120 that are directly connected to the blown fuse 112 are all closed to connect the unblown fuse 112 that is connected to the closed switch element 122 with the conductive line 10.

[0055] See also Figure 3 Take, for example, a switch element 122 is disposed between the first ends of two adjacent fuses 112 in the first connection line 130 , and the first connection line 130 is connected to the conductive line 10 via the first node 200 , and the second node 210 of the second connection line 140 is connected to the conductive line 10 .

[0056] For example, when the circuit protection device 100 is disposed in the conductive line 10 of the circuit, and the plurality of fuses 122 are not blown, the switch elements 1221, 1222, and 122m can all be disconnected. Thus, the fuse 1121 can be connected to the conductive line, so that the conductive line forms a current path through the fuse 1121. In the event of a fault such as an overcurrent or a short circuit in the conductive line, the fuse 1121 may be blown. At this time, the current path in the conductive line 10 is cut off.

[0057] After the faults such as overcurrent or short circuit are eliminated, the switch element 122 directly connected to the blown fuse 1121 is the switch element 1221, which is controlled by the on control signal of the control unit. Accordingly, the switch element 1221 is closed. Thus, the fuse 1122 can be connected to the conductive line 10, so that the conductive line can form a current path through the fuse 1122.

[0058] When the fuse 1122 is in a normal state, the switch elements 122 between the fuse 1122 and the first node 200 are all in a closed state. Among them, the switch element 122 between the fuse 1122 and the first node 200 is the switch element 1221. And the switch element 122 not between the fuse 1122 and the first node 200 is in an open state. That is, the switch elements 1222 to 122n are in an open state.

[0059] Furthermore, if the conductive line has an overcurrent or short circuit fault again, the fuse 1122 may also be blown. Controlled by the on control signal of the control unit, the switch element 1222 can be further closed on the basis of keeping the switch element 1221 closed. That is, the switch element directly connected to the fuse 1122 is closed. As a result, the conductive line can form a new conductive path through the fuse 1123.

[0060] In this embodiment, direct connection may refer to a connection method in which the connection is performed without passing through the switch element 122 .

[0061] In some embodiments, the circuit protection device 100 may further include a detection device 150. After detecting that the fuse 112 connected to the conductive line 10 is blown, the detection device 150 may send a detection signal indicating that the fuse 112 is blown to the control unit.

[0062] In this embodiment, the detection device 150 may be a device connected to the fuse group 110 and capable of detecting current. For example, the detection device 150 may be a current acquisition device disposed in the first node 200 of the first connection line 130 or the second node 210 of the second connection line 140. After the current value collected by the current acquisition device is less than a set threshold value and lasts for a specified period of time, the current acquisition device may consider that the fuse 112 connected to the conductive line 10 has been blown. Thus, the current acquisition device may provide a detection signal indicating that the fuse 112 has been blown to the control unit in a wired or wireless manner.

[0063] Of course, the detection device 150 may also be a micro switch. Specifically, after the fuse 112 connected to the conductive wire 10 is blown, in response to the mechanical structure change caused by the moment of the fuse 112 being blown, the micro switch may be triggered and send a trigger signal of the micro switch to the control unit. The trigger signal may be used as a detection signal sent to the control unit indicating that the fuse 112 is blown.

[0064] In summary, in the multiple embodiments provided in this specification, by providing a fuse group including multiple fuses and a switch unit for controlling the connection and disconnection between the fuses of the fuse group and the conductive wires, the maintenance cost of the fuses can be reduced.

[0065] In some embodiments, the fuses in the fuse group may be disposable fuses, or may include other types (e.g., recoverable fuses). For example, when the fuses in the fuse group include recoverable fuses, through the circuit protection device provided in the embodiments of this specification, multiple recoverable fuses may work in sequence according to the queue order. This may give the recoverable fuses more recovery time, thereby improving the safety of the circuit.

[0066] The embodiments of the present specification also provide a power conversion device. The power conversion device is provided with the circuit protection device 100 described in any of the above embodiments. The power conversion device may include a controller. The control unit involved in the circuit protection device may be the controller of the power conversion device. In some embodiments, the controller may be used to send a connection control signal to the switch unit 120 after the fuse 112 connected to the conductive line 10 has been blown and when a system recovery signal is received, so as to control the connection between the blown fuse 112 and the conductive line 10.

[0067] The role of the circuit protection device 100 in the power conversion device can be referred to the above embodiment. This embodiment will not be described in detail here.

[0068] In some embodiments, the circuit protection device 100 can be used to be arranged on any bus of a power conversion device. The bus on which the circuit protection device 100 is arranged can include a DC bus 180 or an AC bus 190 .

[0069] See also Figure 4 . Figure 4 In an embodiment of a power conversion device provided, a circuit protection device 100 may be disposed on a DC bus 180 of the power conversion device. The DC bus 180 may include a positive DC bus 182 and a negative DC bus 184. In this embodiment, the circuit protection device 100 may include two corresponding groups of fuse groups 110 and switch units 120. Specifically, in this embodiment, the circuit protection device 100 may include a fuse group 1101 and a switch unit 1201 disposed on the positive DC bus 182, and a fuse group 1102 and a switch unit 1202 disposed on the negative DC bus 184.

[0070] In this embodiment, after the fault is eliminated, the control unit 160 of the power conversion device can be used to send a connection control signal to the switch unit 1201 and the switch unit 1202 to control the unblown fuse 112 in the fuse group 110 to be connected to the positive DC bus 182 or the negative DC bus 184.

[0071] See also Figure 5 . Figure 5 A flow chart of automatically resuming operation of a power conversion device having a circuit protection device 100 disposed at a DC bus 180 after a fault is shown.

[0072] Step S110: A short circuit occurs in the positive DC bus 182 or the negative DC bus 184 of the power conversion device. At this time, a relatively large short circuit current may occur in the positive DC bus 182 or the negative DC bus 184 .

[0073] Step S120: The fuse 112 connected to the positive DC bus 182 and / or the negative DC bus 184 is blown. The fuse 112 connected to the positive DC bus 182 and / or the negative DC bus 184 may be blown under the action of the short-circuit current. The blown fuse 112 is a fuse 112 in the fuse group 110 of the positive DC bus 182 or the negative DC bus 184.

[0074] Step S130: troubleshooting. There may be many situations in which the positive DC bus or the negative DC bus of the power conversion device is short-circuited. In some cases, the fault can be checked and resolved by the staff to prevent the short circuit or overcurrent from occurring again. Of course, in some cases, the control unit 160 can also automatically troubleshoot the fault through operations such as self-starting. The embodiments of this specification are not specifically limited here.

[0075] Step S140: the control unit 160 may send a switch-on control signal to the switch unit 120. Specifically, after the fault is resolved, the controller may receive a signal indicating that the fault is resolved, and then may send a switch-on control signal to the switch unit 120 to resume operation of the power conversion device.

[0076] Step S150: After receiving the on-control signal, the switch unit 120 switches the fuse 112 in the fuse group 110 based on the power supply of the power supply unit 170. For example, the switch unit 120 may include a plurality of switch elements 122. Each switch element 122 may have a control end that is turned on by receiving a voltage. Switching the fuse 112 in the fuse group 110 based on the power supply of the power supply unit 170 may indicate that the power supply unit 170 applies a voltage to the control end of the switch element 122 to close the switch element 122. Thus, the switch unit 120 can connect the unblown fuse 112 in the fuse group 110 to the positive DC bus 182 or the negative DC bus 184. Of course, the control signal may also be the on-control signal issued by the control unit. The embodiments of this specification are not specifically limited here.

[0077] Step S160: The power conversion device resumes operation. Specifically, after the unblown fuse 112 is connected, the power conversion device can resume normal operation.

[0078] In some embodiments, the busbar where the circuit protection device 100 is disposed may include an AC busbar 190. The AC busbar 190 may include an A-phase busbar 192, a B-phase busbar 194, and a C-phase busbar 196.

[0079] See also Figure 6 . Figure 6 In an embodiment of a power conversion device provided, a circuit protection device 100 may be disposed on an AC bus 190 of the power conversion device. The AC bus 190 may include an A-phase bus 192, a B-phase bus 194, and a C-phase bus 196. In this embodiment, the circuit protection device 100 may include three corresponding fuse groups 110 and switch units 120. Specifically, in this embodiment, the circuit protection device 100 may include a fuse group 1103 and a switch unit 1203 disposed on the A-phase bus 192, a fuse group 1104 and a switch unit 1204 disposed on the B-phase bus 194, and a fuse group 1105 and a switch unit 1205 disposed on the C-phase bus 196.

[0080] In this embodiment, after the fault is eliminated, the control unit 160 of the power conversion device can be used to send a connection control signal to the switch unit 1203, the switch unit 1204 and the switch unit 1205 to control the unblown fuse 112 in the fuse group 110 to be connected to the A phase bus 192, the B phase bus 194 or the C phase bus 196.

[0081] See also Figure 7 . Figure 7 A flow chart showing the automatic recovery of operation of a power conversion device having a circuit protection device 100 disposed at an AC bus 190 after a fault.

[0082] Step S210: A short circuit occurs in any phase line of the power conversion device. At this time, a large short circuit current may occur in the A-phase bus 192, the B-phase bus 194 or the C-phase bus 196.

[0083] Step S220: The fuse 112 connected to the A-phase bus 192, the B-phase bus 194 or the C-phase bus 196 is blown. Specifically, under the action of the short-circuit current, the blown fuse 112 may be the fuse 112 connected to the A-phase bus 192, the B-phase bus 194 or the C-phase bus 196.

[0084] Step S230: troubleshooting. Specifically, the staff can troubleshoot and solve the fault. Alternatively, the control unit of the power conversion device can execute the troubleshooting method. The embodiments of this specification are not specifically limited here.

[0085] Step S240 : the control unit 160 may send a switch-on control signal to the switch unit 120 .

[0086] Step S250: After receiving the on control signal, the switch unit 120 switches the fuse 112 in the fuse group 110 based on the power supply of the power supply unit 170. Thus, the switch unit 120 can connect the unblown fuse 112 in the fuse group 110 to the A-phase bus 192, the B-phase bus 194 or the C-phase bus 196.

[0087] Step S260: The power conversion device resumes operation. Specifically, after the unblown fuse 112 is connected, the power conversion device can resume normal operation.

[0088] In some embodiments, the circuit protection device 100 may be arranged on the DC bus 180 side and the AC bus 190 side of the power conversion device.

[0089] See also Figure 8 . Figure 8In an embodiment of a power conversion device provided, a DC bus 180 and an AC bus 190 of the power conversion device may be both provided with a circuit protection device 100. The DC bus 180 may include a positive DC bus 182 and a negative DC bus 184. The AC bus 190 may include an A-phase bus 192, a B-phase bus 194, and a C-phase bus 196.

[0090] In this embodiment, the circuit protection device 100 disposed on the DC bus 180 may include two corresponding fuse groups 110 and switch units 120. Specifically, in this embodiment, the circuit protection device 100 disposed on the DC bus 180 may include a fuse group 1101 and a switch unit 1201 disposed on the positive DC bus 182, and a fuse group 1102 and a switch unit 1202 disposed on the negative DC bus 184.

[0091] The circuit protection device 100 disposed on the AC bus 190 may include three corresponding fuse groups 110 and switch units 120. Specifically, in this embodiment, the circuit protection device 100 may include a fuse group 1104 and a switch unit 1204 disposed on the A-phase bus 192, a fuse group 1105 and a switch unit 1205 disposed on the B-phase bus 194, and a fuse group 1106 and a switch unit 1206 disposed on the C-phase bus 196.

[0092] In this embodiment, when the fuse 112 in the DC bus 180 or the AC bus 190 is blown, the control logic of the control unit 160 is similar to that of the above embodiment. This embodiment will not be described in detail here.

[0093] When the fuses 112 in the DC bus 180 and the AC bus 190 are both blown and the fault is eliminated, the control unit 160 of the power conversion device can be used to send a connection control signal to the switch unit 1201 or the switch unit 1202 in the circuit protection device 100 arranged on the DC bus 180, and to send a connection control signal to the switch unit 1203, the switch unit 1204 or the switch unit 1205 in the circuit protection device 100 arranged on the AC bus 190, so as to control the unblown fuses 112 in the fuse group 110 arranged on the DC bus 180 to be connected to the positive DC bus 182 or the negative DC bus 184, and to control the unblown fuses 112 in the fuse group 110 arranged on the AC bus 190 to be connected to the A-phase bus 192, the B-phase bus 194 and the C-phase bus 196.

[0094] See also Fig. 9 . Figure 7 A flow chart showing the automatic recovery of operation of a power conversion device having a circuit protection device 100 disposed at an AC bus 190 after a fault.

[0095] Step S310: The positive DC bus 182 or the negative DC bus 184 of the power conversion device is short-circuited, and any phase line of the power conversion device is short-circuited. At this time, a large short-circuit current may appear in the positive DC bus 182 or the negative DC bus 184, and a large short-circuit current may also appear in the A-phase bus 192, the B-phase bus 194 or the C-phase bus 196.

[0096] Step S320: The fuse 112 that is short-circuited with the positive DC bus 182 or the negative DC bus 184 is blown, and the fuse 112 that is connected to the A-phase bus 192 , the B-phase bus 194 , or the C-phase bus 196 is blown.

[0097] Step S330: troubleshooting. In this embodiment, troubleshooting can be performed by a staff member or by a controller of the power conversion device. This embodiment of the specification does not specifically limit this.

[0098] Step S340: After the fault is eliminated, the control unit 160 sends a switch-on control signal to both the switch unit 120 on the DC side and the switch unit 120 on the AC side.

[0099] Step S350: After receiving the on control signal, the switch unit 120 switches the fuse 112 in the fuse group 110 based on the power supply of the power supply unit 170. Thus, the switch unit 120 can connect the unblown fuse 112 in the fuse group 110 provided on the AC bus 190 with the A-phase bus 192, the B-phase bus 194 or the C-phase bus 196, and connect the unblown fuse 112 in the fuse group 110 provided on the DC bus 180 with the positive DC bus 182 or the negative DC bus 184.

[0100] Step S360: The power conversion device resumes operation.

[0101] In some embodiments, the power conversion device may further include a power supply unit that can supply power to the switch unit and the controller when the fuse connected to the conductive line is in a blown state. In this embodiment, the power supply unit may be an independent power supply unit. For example, the power supply unit may use an uninterruptible power supply (UPS) and use a power board for AC and DC power supply. Even when the power conversion device is applied to an energy storage system or a renewable energy power generation system, when a fault occurs on the DC source side or the grid side and power cannot be supplied, the power supply unit may supply power to the switch unit to avoid damage to the power equipment to a certain extent due to the short-circuit current caused by the fault on the DC source side or the grid side.

[0102] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. can transmit electrical signals or data to each other.

[0103] It should be understood that the specific examples in this document are only intended to help those skilled in the art better understand the embodiments of this specification, rather than to limit the scope of the present invention.

[0104] It can be understood that in the various embodiments in this specification, the size of the sequence number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this specification.

[0105] It can be understood that the various embodiments described in this specification can be implemented individually or in combination, and the embodiments of this specification are not limited to this.

[0106] Unless otherwise stated, all technical and scientific terms used in the embodiments of this specification have the same meaning as those generally understood by those skilled in the art of the technical field of this specification. The terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the scope of this specification. The term "and / or" used in this specification includes any and all combinations of one or more related listed items. The singular forms of "a kind of", "above" and "the" used in the embodiments of this specification and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0107] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this specification.

[0108] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0109] In the several embodiments provided in this specification, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0110] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0111] The above is only a specific embodiment of this specification, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in this specification, which should be included in the protection scope of this specification. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A circuit protection device, characterized in that: The circuit protection device comprises: a fuse group and a switch unit for being arranged in any conductive line of the circuit; The fuse group includes a plurality of fuses connected in parallel; the switch unit is used to control the connection and disconnection between at least one fuse in the fuse group and the conductive line; After the fuse connected to the conductive line is blown, the switch unit connects at least one unblown fuse among the plurality of fuses to the conductive line in response to a turn-on control signal sent by a control unit.

2. The circuit protection device according to claim 1, characterized in that: The switch unit comprises a plurality of switch elements; the plurality of fuses respectively have a first end connected via a first connection line and a second end connected via a second connection line; The switch element is arranged between the first ends of two adjacent fuses in the first connecting line; And / or, the switch element is arranged between the second ends of two adjacent fuses in the second connecting line.

3. The circuit protection device according to claim 2, characterized in that: After the fuse connected to the conductive line is blown, the switch elements in the switch unit directly connected to the blown fuse are closed to connect the unblown fuse connected to the closed switch elements to the conductive line.

4. The circuit protection device according to claim 2, characterized in that: The first connecting line has a first node connected to the conductive line, and the second connecting line has a second node connected to the conductive line; When the fuse connected to the conductive line is in a normal state, the switching elements arranged between the fuse and the first node, or between the fuse and the second node are in a closed state, and the switching elements not between the fuse and the first node, or between the fuse and the second node are in an open state.

5. The circuit protection device according to claim 1, characterized in that: The circuit protection device also includes a detection device; After detecting that the fuse connected to the conductive line is blown, the detection device sends a detection signal indicating that the fuse is blown to the control unit.

6. A power conversion device, characterized in that: The power conversion device is provided with the circuit protection device according to any one of claims 1 to 5, and the control unit is a controller of the power conversion device.

7. The power conversion device according to claim 6, characterized in that: The circuit protection device is used to be arranged on any bus of a power conversion device; wherein the bus includes a DC bus or an AC bus.

8. The power conversion device according to claim 7, characterized in that: The DC bus of the power conversion device includes a DC positive bus and a DC negative bus; the circuit protection device includes a plurality of corresponding fuse groups and switch units; The DC positive busbar and the DC negative busbar are respectively provided with at least one pair of fuse groups and switch units.

9. The power conversion device according to claim 7, characterized in that: The AC busbar of the power conversion circuit includes an AC A-phase busbar, an AC B-phase busbar and an AC C-phase busbar; the circuit protection device includes a plurality of corresponding fuse groups and switch units; The AC A-phase busbar, the AC B-phase busbar and the AC C-phase busbar are respectively provided with at least one pair of fuse groups and switch units.

10. The power conversion device according to claim 6, characterized in that: The power conversion device further includes a power supply unit capable of supplying power to the switch unit and the controller when a fuse connected to the conductive line is in a blown state.

11. The power conversion device according to claim 6, characterized in that: The controller is used for sending a connection control signal to the switch unit after the fuse connected to the conductive line has been blown and when receiving a system recovery signal, so as to control the blown fuse to be connected to the conductive line.

12. An energy system, characterized in that: include: The power conversion device according to any one of claims 6 to 11; the AC side of the power conversion device is used to connect to a power grid.

Images