Breaking device, power transmission equipment and power conversion system
By introducing a synchronization circuit and a signal fuse into the excitation fuse design, the problem of the excitation fuse's breaking reliability under conditions of no external excitation signal or power supply failure is solved, achieving synchronous breaking in case of fault and improving the reliability of overcurrent protection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-11
- Publication Date
- 2026-03-27
AI Technical Summary
In the existing technology, the excitation fuse cannot reliably achieve synchronous interruption of fault current in the absence of external excitation signal or controller power supply, especially in overcurrent fault scenarios such as reverse connection or short circuit, which leads to a high risk of interruption failure.
A disconnecting device employing a synchronous circuit and at least two excitation fuses, with the signal fuse and excitation fuse connected in series, controls the disconnector's operation via an arc voltage signal, achieving synchronous disconnection of the excitation fuses without relying on an external power supply.
This improves the reliability of overcurrent protection, ensuring that the excitation fuses can disconnect synchronously without external power supply, thus reducing the risk of disconnection failure.
Smart Images
Figure CN121749074A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of power electronics technology, and in particular to a disconnection device, power transmission equipment and power conversion system. Background Technology
[0002] In power transmission lines, overcurrent protection against faults such as reverse connection, forward overcurrent, or short circuit can be achieved by using series-connected energized fuses. For example, in the event of a reverse connection on either side of the power transmission line, or in the event of an overcurrent in the power transmission line, the fault current is interrupted by the tripping of the energized fuse, thus achieving overcurrent protection.
[0003] However, in practical applications, if the excitation fuse does not have an external excitation signal, or if the controller that generates the external excitation signal is not powered, the excitation fuse that cuts off the fault current loop cannot disconnect synchronously. For example, in scenarios such as reverse connection or DC side arcing requiring complete disconnection from external electrical connections, the above solution cannot achieve reliable protection. Summary of the Invention
[0004] In view of the above problems, this disclosure provides a disconnection device, a power transmission device, and a power conversion system to improve the reliability of overcurrent protection. The specific solution is as follows:
[0005] The first aspect of this disclosure provides a disconnection device, comprising: a synchronization circuit and at least two excitation fuses; wherein,
[0006] The excitation fuse includes a signal fuse and a circuit breaker;
[0007] The signal fuse is connected in series in the current branch where the excitation fuse is located;
[0008] The two ends of the signal fuse are connected to the corresponding input terminals of the synchronization circuit;
[0009] The output terminal of the synchronization circuit is connected to the input terminal of the disconnector;
[0010] The synchronization circuit is configured to generate and output a trigger signal to the circuit breaker in response to the arc voltage signal of the signal fuse; the arc voltage signal is the response signal of the signal fuse to an overcurrent fault in the current branch in which it is located.
[0011] In one possible implementation, the inputs of each of the circuit breakers are also configured to operate in response to receiving an external excitation signal.
[0012] In one possible implementation, the synchronization circuit also has an input terminal configured to receive an external excitation signal;
[0013] The synchronization circuit is also configured to generate and output a trigger signal to the disconnector in response to the external excitation signal.
[0014] In one possible implementation, electromagnetic switching is used to isolate the input and output of the synchronization circuit.
[0015] In one possible implementation, the inputs of each of the circuit breakers are connected in parallel to the same output of the synchronization circuit.
[0016] In one possible implementation, the synchronization circuit has multiple output terminals, each connected to the input terminal of the corresponding interruptor.
[0017] In one possible implementation, the excitation fuse further includes an arc-extinguishing device for extinguishing the electric arc generated during the operation of the circuit breaker.
[0018] A second aspect of this disclosure provides a power transmission device, comprising: at least one disconnecting device as described in the first aspect or any implementation thereof; wherein...
[0019] The excitation fuse of the disconnecting device is connected in series in at least one current branch of the power transmission device.
[0020] The excitation fuses that need to be disconnected simultaneously are controlled by a synchronization circuit in the same disconnecting device.
[0021] In one possible implementation, the power transmission device has a DC side, which has multiple transmission branches, including a positive current branch and a negative current branch; the power transmission device also includes at least one bus branch, which is connected to the DC side through at least two of the transmission branches.
[0022] In the same transmission branch, the excitation fuse connected in series in the positive current branch and the excitation fuse connected in series in the negative current branch are the excitation fuses that need to be disconnected simultaneously.
[0023] Alternatively, all the excitation fuses in each of the transmission branches are the excitation fuses that need to be disconnected simultaneously.
[0024] In one possible implementation, the power transmission device has an AC side, and the excitation fuses connected in series in each phase current branch of the AC side are the excitation fuses that need to be disconnected simultaneously.
[0025] In one possible implementation, the power transmission device has a DC side with multiple transmission branches; the power transmission device also includes at least one bus branch, which is connected to the DC side through at least two of the transmission branches.
[0026] The power transmission device also includes:
[0027] DC / AC conversion circuit, wherein the DC / AC conversion circuit is connected between the bus branch and the AC side of the power transmission device;
[0028] Alternatively, a DC / AC conversion circuit and at least one DC / DC conversion circuit, wherein the AC side of the DC / AC conversion circuit is connected to the AC side of the power transmission device, and the DC side of the DC / AC conversion circuit is connected to the corresponding bus branch through the DC / DC conversion circuit.
[0029] Alternatively, a DC / DC converter circuit, wherein the bus branch is connected to each of the corresponding transmission branches through the DC / DC converter circuit.
[0030] In one possible implementation, the power transmission device further includes: at least one DC switching module;
[0031] The DC switch module is connected between the bus branch and each of the excitation fuses connected to the bus branch.
[0032] A third aspect of this disclosure provides a power conversion system, comprising: a controller and at least one power transmission device as described in the second aspect or any implementation thereof; wherein...
[0033] The power transmission device is controlled by the controller.
[0034] The breaking device provided by this disclosure, using the above technical solution, includes: a synchronization circuit and at least two excitation fuses; wherein, the excitation fuses include a signal fuse and a breaker; the signal fuse is connected in series in the current branch where the excitation fuse is located, so that an arc voltage signal can be generated to respond when an overcurrent fault occurs in the current branch; the two ends of the signal fuse are connected to the corresponding input terminals of the synchronization circuit, and the output terminal of the synchronization circuit is connected to the input terminal of the breaker; the synchronization circuit is configured to: generate and output a trigger signal to the breaker in response to the arc voltage signal of the signal fuse, thereby controlling the breakers to operate simultaneously, thereby enabling the excitation fuses to break simultaneously, improving the reliability of overcurrent protection. Attached Figure Description
[0035] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.
[0036] Figure 1 A schematic diagram of the fault current loop when a reverse connection fault occurs in an inverter provided by a traditional solution.
[0037] Figure 2 A schematic diagram of the structure of the disconnecting device provided in an embodiment of this disclosure;
[0038] Figure 3 Another schematic diagram of the breaking device provided in the embodiments of this disclosure;
[0039] Figure 4 Another schematic diagram of the breaking device provided in the embodiments of this disclosure;
[0040] Figure 5 A schematic diagram of a synchronous circuit in a disconnection device provided in an embodiment of this disclosure;
[0041] Figure 6 Another schematic diagram of the breaking device provided in the embodiments of this disclosure;
[0042] Figure 7 Another schematic diagram of the breaking device provided in the embodiments of this disclosure;
[0043] Figure 8 A schematic diagram of a power transmission device provided in an embodiment of this disclosure;
[0044] Figure 9 This is another schematic diagram of the power transmission device provided in the embodiments of this disclosure;
[0045] Figure 10 This is a schematic diagram of a centralized photovoltaic inverter system or a distributed photovoltaic inverter system provided in an embodiment of this disclosure;
[0046] Figure 11 A schematic diagram of a structure provided in this disclosure when the disconnection device is disposed outside the power transmission equipment;
[0047] Figure 12 A schematic diagram of a string photovoltaic inverter system provided in an embodiment of this disclosure;
[0048] Figure 13 This is a schematic diagram of another structure of the string photovoltaic inverter system provided in an embodiment of the present disclosure;
[0049] Figure 14This is a schematic diagram of the combiner box in a distributed photovoltaic inverter system provided in an embodiment of this disclosure. Detailed Implementation
[0050] The embodiments of this disclosure are described below with reference to the accompanying drawings. The terminology used in the Description of Embodiments section of this disclosure is for illustrative purposes only and is not intended to limit the scope of this disclosure.
[0051] The embodiments of this disclosure are described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure. Those skilled in the art will understand that with the development of technology and the emergence of new scenarios, the technical solutions provided by the embodiments of this disclosure are also applicable to similar technical problems.
[0052] The terms “first,” “second,” etc., used in this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the description of embodiments of this disclosure. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of units is not necessarily limited to those units, but may include other units not expressly listed or inherent to those processes, methods, products, or apparatuses.
[0053] As a new type of fuse, the excitation fuse has an external triggering function for active tripping. There are three common types of excitation fuses: self-excited, self-excited + externally excited, and externally excited. For the latter two types, when using external excitation control, if the circuit is under certain operating conditions, such as reverse connection, forward overcurrent, or short circuit, requiring several excitation fuses to trip simultaneously, then as long as the system has power, multiple excitation fuses can be simultaneously externally excited to trip them at the same time. However, in certain scenarios, such as... Figure 1When the DC side of the inverter in the centralized photovoltaic inverter system shown is equipped with an excitation fuse, if there is no voltage on the AC side of the system (taking the example of reversing the positive and negative connections of the cable from combiner box N to inverter 10 during on-site construction), the fault current is shown by the dotted line with arrows in the figure. In this case, the DC side of the system is short-circuited and has no power. Therefore, it is impossible to supply power to the controller that externally excites the excitation fuse, i.e., external excitation control cannot be achieved. At this time, the self-excited + externally excited type excitation fuse can still achieve passive breaking through self-excitation, but the risk of breaking failure is very high. For example, if the fault current is not large enough, the positive and negative excitation fuses connected to combiner box N cannot break simultaneously. Then, the excitation fuse that breaks prematurely will be subjected to twice the input voltage, which is far greater than the breaking capacity of the excitation fuse, leading to the excitation fuse breaking failure.
[0054] Therefore, this disclosure provides a disconnection device to improve the reliability of overcurrent protection. The specific solution is as follows:
[0055] like Figure 2 As shown, the disconnecting device includes: a synchronization circuit 20 and at least two excitation fuses 10; wherein:
[0056] The excitation fuse 10 includes a signal fuse 101 and a circuit breaker 102. The signal fuse 101 is connected in series in the current branch where the excitation fuse 10 is located. Therefore, when an overcurrent fault such as reverse connection, forward overcurrent, or short circuit occurs in this current branch, the signal fuse 101 generates a corresponding voltage across itself as an arc voltage signal based on the magnitude of the current flowing through it. That is, the arc voltage signal is the response signal of the signal fuse 101 to an overcurrent fault in its current branch. In practical applications, the excitation fuse 10 may also include an arc-extinguishing device 103 to extinguish the arc generated accompanying the operation of the circuit breaker 102.
[0057] The two ends of the signal fuse 101 are connected to the corresponding input terminals of the synchronization circuit 20. That is, each input terminal of the synchronization circuit 20 is connected to the corresponding signal fuse 101. Furthermore, the arc voltage signal generated by the signal fuse 101 can be output to the synchronization circuit 20.
[0058] The output of the synchronization circuit 20 is connected to the input of the circuit breaker 102. The synchronization circuit 20 is configured to generate and output a trigger signal to the circuit breaker 102 in response to the arc voltage signal of the signal fuse 101. This trigger signal can control the operation of the circuit breaker 102. Since each circuit breaker 102 can receive the trigger signal, as long as one signal fuse 101 sends an arc voltage signal to the synchronization circuit 20, the synchronization circuit 20 can generate a trigger signal, thereby controlling the operation of each circuit breaker 102 simultaneously, and thus enabling each excitation fuse 10 to disconnect synchronously.
[0059] That is, in the excitation fuse 10, the signal fuse 101 used to achieve self-excitation is not directly connected to the circuit breaker 102, but is connected to the circuit breaker 102 through the synchronization circuit 20. This allows the circuit breaker 102 of each excitation fuse 10 to be controlled by the synchronization circuit 20. When the synchronization circuit 20 receives the arc voltage signal output by any signal fuse 101, it can control the operation of each circuit breaker 102. This can achieve synchronous interruption of each excitation fuse 10 without the need for external power supply, thus improving the reliability of overcurrent protection.
[0060] Based on the above principles, the synchronization circuit 20 can achieve synchronous disconnection of each of its connected excitation fuses 10. Therefore, in practical applications, if there are multiple excitation fuses 10 in the system circuit, the excitation fuses 10 that need to be disconnected simultaneously can be connected to the same synchronization circuit 20. When the current in the circuit exceeds the long-term current carrying capacity of the excitation fuse 10, the trigger signal fuse 101 outputs an arc voltage signal; the arc voltage signal is processed by the synchronization circuit 20, and the output trigger signal can trigger the synchronous disconnection of the excitation fuses 10 that need to be disconnected simultaneously.
[0061] Figure 2 Taking two excitation fuses 10 as an example, the two ends of the signal fuse 101 in each excitation fuse 10 are respectively connected to the corresponding input terminals of the synchronization circuit 20, and the output terminal of the synchronization circuit 20 is connected to the input terminal of the circuit breaker 102 in each excitation fuse 10. When an overcurrent fault occurs first in the current branch where one of the excitation fuses 10 is located, its signal fuse 101 generates an arc voltage signal, which outputs a trigger signal through the synchronization circuit 20, simultaneously triggering the circuit breakers 102 of both excitation fuses 10, ensuring that the two excitation fuses 10 operate synchronously.
[0062] The breaking device provided in this embodiment, through the above principle, can control the breakers 102 of each excitation fuse 10 to operate simultaneously, thereby enabling these excitation fuses 10 to break simultaneously and improving the reliability of overcurrent protection.
[0063] In the previous embodiment, the excitation fuse 10 in the breaking device was described as a self-excited type. In practical applications, each excitation fuse 10 can also be a self-excited + externally excited type. In this case, the excitation fuse 10 in the breaking device can also be controlled by an external excitation signal, and the way the external excitation signal acts is not limited, for example:
[0064] See Figure 3 Each circuit breaker 102's input terminal is also used to receive an external excitation signal, and each circuit breaker 102 will also operate when it receives the external excitation signal. That is, each circuit breaker 102's input terminal can operate when it receives at least one of a trigger signal and an external excitation signal, thereby breaking the corresponding excitation fuse 10.
[0065] Or see Figure 4 The synchronization circuit 20 also has an input terminal configured to receive an external excitation signal; the synchronization circuit 20 is also configured to generate and output a trigger signal to the circuit breaker 102 in response to the external excitation signal. That is, the synchronization circuit 20 can generate a trigger signal when it receives at least one of the arc voltage signal and the external excitation signal, thereby controlling the operation of each circuit breaker 102 to disconnect each excitation fuse 10.
[0066] When each excitation fuse 10 adopts a self-excited + external excitation type excitation fuse, it can be controlled by any excitation control to disconnect, and no limitation is made here.
[0067] Based on the above embodiments, in this disconnection device, the input and output terminals of the synchronization circuit 20 can be isolated by electromagnetic conversion.
[0068] Synchronous circuit 20 can use magnetic isolation technology, such as, when no external power supply is required. Figure 5 As shown, its input and output terminals are respectively led out through corresponding windings. These windings can also be wound on corresponding magnetic core structures, which is not limited here. In practical applications, other methods can also be used to achieve isolation between input and output. As long as a signal, i.e., the arc voltage signal mentioned above, exists at any input terminal, the corresponding signal, i.e., the trigger signal mentioned above, is generated at the output terminal, all of which are within the protection scope of this disclosure.
[0069] The disconnection device provided in this embodiment, through the isolation technology of the synchronization circuit 20, not only enables different excitation fuses 10 to disconnect synchronously without external control power supply, but also improves safety through signal isolation.
[0070] Based on the above embodiments, the breaking device can also be expanded to include more excitation fuses 10 that can be broken simultaneously, such as... Figure 6 As shown in the figure. In practical applications, the number of excitation fuses 10 connected to the same synchronization circuit 20 is not limited, but depends on the specific application environment, and all are within the protection scope of this disclosure.
[0071] Furthermore, the above embodiments all demonstrate the use of only one output terminal of the synchronization circuit 20 to output the trigger signal. In this case, the input terminals of each circuit breaker 102 are connected in parallel to the same output terminal of the synchronization circuit 20. In practical applications, the synchronization circuit 20 can also use multiple output terminals to output the trigger signal separately, and each output terminal can be connected to the input terminal of the corresponding circuit breaker 102. Figure 7 The example shown uses two excitation fuses (10).
[0072] Figure 6In the process, the synchronous circuit 20 uses one output terminal to simultaneously output trigger signals to each circuit breaker 102, so that each circuit breaker 102 operates at the same time.
[0073] Figure 7 In this circuit, the synchronization circuit 20 simultaneously outputs the same trigger signal to each circuit breaker 102 through multiple output terminals, which can also make each circuit breaker 102 operate simultaneously. The case where the synchronization circuit 20 is connected to more excitation fuses 10 is not shown.
[0074] When the synchronization circuit 20 outputs a trigger signal through a multiplexer, it can... Figure 5 Based on this, simply increase the number of output terminals; no further diagram is needed.
[0075] Furthermore, in practical applications, regardless of the method used to output the trigger signal at the output terminal of the synchronization circuit 20, it does not affect the selection of the excitation fuse 10. That is, it can be a self-excited excitation fuse or a self-excited + external excitation excitation fuse; it depends on the specific application environment, and all of them are within the protection scope of this disclosure.
[0076] Another embodiment of this disclosure also provides a power transmission device, such as... Figure 8 The diagram shows at least one disconnecting device as described in any of the above embodiments; the structure and principle of this disconnecting device can be found in the above embodiments, and will not be repeated here. Additionally:
[0077] The two sides of the power transmission device 100 can be referred to as the first side and the second side, respectively. The first side is used to connect to the power source, and the second side is used to directly connect to the power grid and / or the load or to connect to the power grid and / or the load through other circuits.
[0078] In practical applications, the power transmission device 100 can be used as different devices in a power conversion system. For example, the power transmission device 100 can be used as an inverter, such as a photovoltaic inverter that is only connected to a photovoltaic power source, an energy storage converter that is only connected to an energy storage power source, or a photovoltaic-energy storage integrated machine that is connected to both a photovoltaic power source and an energy storage power source. In this case, each path on its first side can be directly connected to the corresponding power source, or it can be connected to the corresponding power source through a combiner box. Alternatively, the power transmission device 100 can also be used as a combiner box, in which case each path on its first side can be directly connected to the corresponding power source.
[0079] The power transmission device 100 has an excitation fuse (FU1+, FU1-, ..., FUN+ or FUN- as shown in the figure) connected in series in the current branch of at least one side; the current branch can refer to any pole branch on the DC side of the power transmission device 100, or any phase branch on the AC side of the power transmission device 100. Figure 8The example shown is an arbitrary branch on the DC side of the power transmission device 100. Figure 8 As shown, in each DC-side path (including paths 1 to N) of the power transmission device 100, each path includes a two-pole branch, namely a positive current branch and a negative current branch. Figure 8 The example shown uses the case where each current branch has a corresponding excitation fuse connected in series. In practical applications, the corresponding excitation fuse can also be connected in series only in each single-pole current branch (such as the positive current branch or the negative current branch). Figure 9 The example shown is that only the corresponding excitation fuses are connected in series in each positive current branch; however, the specific application environment may vary, and all are within the protection scope of this disclosure.
[0080] The excitation fuses that need to be disconnected simultaneously are controlled by the synchronization circuit 20 in the same disconnecting device; Figure 8 and Figure 9 The example shown uses the scenario where all excitation fuses need to be tripped simultaneously.
[0081] In practical applications, such as Figure 8 or Figure 9 As shown, for the case where the power transmission device 100 has a DC side, taking the first side as an example, this DC side has multiple transmission branches 01, including a positive current branch and a negative current branch; the power transmission device 100 also includes at least one bus branch 02, which is connected to the DC side through at least two transmission branches 01. In this case, not only can it be used as... Figure 8 or Figure 9 As shown in the diagram, all excitation fuses in each transmission branch 01 are configured to be excitation fuses that need to be disconnected simultaneously. Alternatively, as shown in the diagram... Figure 10 As shown, the configuration is as follows: in the same transmission branch 01, the excitation fuses connected in series in the positive current branch and the excitation fuses connected in series in the negative current branch are excitation fuses that need to be disconnected simultaneously; that is, the positive and negative excitation fuses of each transmission branch 01 are controlled by the same synchronization circuit (e.g., Figure 10 Synchronization circuit 1, synchronization circuit 2, ... or synchronization circuit N)20 shown.
[0082] Figure 10Taking the power transmission device 100 as an example of an inverter, when an excitation fuse (FU1+, FU1-, FU2+, FU2-, ..., FUN+ and FUN-) is added to its DC side, a synchronization circuit 20 is added to the positive and negative excitation fuses of each transmission branch 01 of the inverter (FU1+ and FU1-, FU2+ and FU2-, or FUN+ and FUN- as shown in the figure) to ensure that the positive and negative excitation fuses of the transmission branch 01 can be disconnected synchronously: as long as one excitation fuse of the positive and negative terminals of each transmission branch 01 is about to disconnect, the other excitation fuse will also disconnect synchronously, which can completely isolate the fault point and improve the reliability of disconnection.
[0083] Figure 11 The example shown uses the power transmission device 100 as an inverter. One side is the AC side, and the excitation fuses (FUa, FUb, and FUc shown in the figure) connected in series in each phase current branch of this AC side are excitation fuses that need to be disconnected simultaneously and are controlled by the same synchronization circuit 20. Furthermore, these excitation fuses and the synchronization circuit 20 can be located inside the inverter or outside the inverter (e.g.,...). Figure 11 (as shown in the image) Figure 11 The example shown uses the inverter's AC side, where each excitation fuse is connected sequentially via a filter inductor L, a filter capacitor C, and an AC switch K. However, practical applications are not limited to this. When adding three-phase excitation fuses (including FUa, FUb, and FUc shown in the diagram) to the inverter's AC side, a synchronization circuit 20 can be added to the three-phase current branches, enabling the three-phase excitation fuses to disconnect synchronously. This allows for rapid disconnection from the grid in the event of a short circuit or other fault on the inverter's DC side.
[0084] The power transmission device 100 provided in this embodiment controls the simultaneous disconnection of each excitation fuse connected to it through the synchronous circuit 20 in the disconnection device, thereby improving the reliability of overcurrent protection.
[0085] Based on the above embodiments, this embodiment provides an exemplary description of specific optional structures for the power transmission device 100, such as:
[0086] The power transmission device 100 has a DC side with multiple transmission branches 01 on the DC side. The power transmission device 100 also includes at least one bus branch 02, which is connected to the DC side through at least two transmission branches 01. In this case, the power transmission device 100 may also include: a DC / AC conversion circuit, a DC / DC conversion circuit, or a DC / AC conversion circuit and at least one DC / DC conversion circuit.
[0087] like Figure 10As shown, the DC / AC conversion circuit 101 is connected between the combiner branch 02 and the AC side of the power transmission device 100; at this time, the power transmission device 100 can be used as an inverter in a centralized photovoltaic inverter system or a distributed photovoltaic inverter system.
[0088] like Figure 12 or Figure 13 As shown, the AC side of the DC / AC conversion circuit 101 is connected to the AC side of the power transmission device 100, and the DC side of the DC / AC conversion circuit 101 is connected to the corresponding bus branch 02 through the DC / DC conversion circuit 102; at this time, the power transmission device 100 can be used as an inverter in a string photovoltaic inverter system.
[0089] like Figure 14 As shown, the combiner branch 02 is connected to each corresponding transmission branch 01 through the DC / DC conversion circuit 202; at this time, the power transmission device 100 can be used as a combiner box in a distributed photovoltaic inverter system.
[0090] Additionally, the power transmission device 100 may also include: at least one DC switching module (such as...) Figure 10 , Figure 12 and Figure 13 The 103 shown, or Figure 14 As shown in 201); the DC switch module is connected between the bus branch 02 and each excitation fuse connected to the bus branch 02.
[0091] Figure 10 , Figure 12 and Figure 13 In this process, the fuses are excited by the positive and negative terminals of each transmission branch 01 (e.g., Figure 10 or Figure 12 The FU1+ and FU1-, FU2+ and FU2-, or FUN+ and FUN- shown; or, as... Figure 13 The following example illustrates that FU1+ and FU1-, FU2+ and FU2-, FUi+ and FUi-, FUj+ and FUj-, FUj+1+ and FUj+1-, or FUN+ and FUN-) are controlled by the same synchronous circuit 20. Figure 11 and Figure 14 In all cases, all energized fuses (such as...) Figure 11 The FUa, FUb, and FUc shown; or, Figure 14 The example shown is that FU1+, FU1-, FU2+ and FU2- are controlled by the same synchronous circuit 20; however, in actual applications, it is not limited to this.
[0092] The power transmission device provided in this embodiment can achieve synchronous disconnection for different excitation fuses without external control power supply by connecting them to the same synchronization circuit 20, so as to quickly and completely disconnect the connection with the fault point and improve the reliability of fault protection.
[0093] Another embodiment of this disclosure provides a power conversion system, including: a controller and at least one power transmission device as described in any of the above embodiments; wherein the power transmission device is controlled by the controller.
[0094] As described in the above embodiments, the power transmission device can be an inverter or a combiner box; through different structural settings, the power conversion system can become a centralized photovoltaic inverter system, a string photovoltaic inverter system, or a distributed photovoltaic inverter system, etc., without limitation, depending on the specific application environment, and all are within the protection scope of this disclosure.
[0095] Furthermore, the power source connected to the power transmission device can be a photovoltaic power source, an energy storage power source, or a DC power source connected to different power sources respectively; there are no restrictions here, it depends on the specific application environment, and all are within the protection scope of this disclosure.
[0096] The power conversion system provided in this embodiment, by employing the aforementioned power transmission equipment, enables different excitation fuses to be synchronously disconnected by connecting to the same synchronization circuit without external control power supply, thereby quickly and completely cutting off the connection with the fault point and improving the reliability of fault protection.
[0097] Similar or identical parts between the various embodiments in this disclosure can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the description of the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment solution according to actual needs. Those skilled in the art can understand and implement this without creative effort.
[0098] Those skilled in the art will also recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this disclosure.
[0099] The above description of the disclosed embodiments shows that the features described in the various embodiments of this disclosure can be substituted for or combined with each other, enabling those skilled in the art to implement or use this disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A disconnection device, characterized in that, include: Synchronization circuit and at least two excitation fuses; wherein, The excitation fuse includes a signal fuse and a circuit breaker; The signal fuse is connected in series in the current branch where the excitation fuse is located; The two ends of the signal fuse are connected to the corresponding input terminals of the synchronization circuit; The output terminal of the synchronization circuit is connected to the input terminal of the disconnector; The synchronization circuit is configured to generate and output a trigger signal to the circuit breaker in response to the arc voltage signal of the signal fuse; the arc voltage signal is the response signal of the signal fuse to an overcurrent fault in the current branch in which it is located.
2. The disconnecting device according to claim 1, characterized in that, The input terminals of each of the circuit breakers are also configured to operate in response to receiving an external excitation signal.
3. The breaking device according to claim 1, characterized in that, The synchronization circuit also has an input terminal, which is configured to receive an external excitation signal; The synchronization circuit is also configured to generate and output a trigger signal to the disconnector in response to the external excitation signal.
4. The disconnecting device according to any one of claims 1 to 3, characterized in that, The input and output terminals of the synchronization circuit are isolated by electromagnetic conversion.
5. The disconnecting device according to any one of claims 1 to 3, characterized in that, The input terminals of each of the aforementioned circuit breakers are connected in parallel to the same output terminal of the synchronization circuit.
6. The disconnecting device according to any one of claims 1 to 3, characterized in that, The synchronization circuit has multiple output terminals, which are respectively connected to the input terminals of the corresponding interrupters.
7. The disconnecting device according to any one of claims 1 to 3, characterized in that, The excitation fuse also includes an arc extinguishing device for extinguishing the electric arc generated during the operation of the circuit breaker.
8. A power transmission device, characterized in that, include: At least one disconnecting device as described in any one of claims 1 to 7; wherein, The excitation fuse of the disconnecting device is connected in series in at least one current branch of the power transmission device. The excitation fuses that need to be disconnected simultaneously are controlled by a synchronization circuit in the same disconnecting device.
9. The power transmission device according to claim 8, characterized in that, The power transmission device has a DC side, and the DC side has multiple transmission branches, including a positive current branch and a negative current branch; the power transmission device also includes at least one bus branch, which is connected to the DC side through at least two of the transmission branches. In the same transmission branch, the excitation fuse connected in series in the positive current branch and the excitation fuse connected in series in the negative current branch are the excitation fuses that need to be disconnected simultaneously. Alternatively, all the excitation fuses in each of the transmission branches are the excitation fuses that need to be disconnected simultaneously.
10. The power transmission device according to claim 8, characterized in that, The power transmission device has an AC side, and the excitation fuses connected in series in each phase current branch of the AC side are the excitation fuses that need to be disconnected simultaneously.
11. The power transmission device according to any one of claims 8 to 10, characterized in that, The power transmission device has a DC side, and the DC side has multiple transmission branches; the power transmission device also includes at least one bus branch, which is connected to the DC side through at least two of the transmission branches; The power transmission device also includes: DC / AC conversion circuit, wherein the DC / AC conversion circuit is connected between the bus branch and the AC side of the power transmission device; Alternatively, a DC / AC conversion circuit and at least one DC / DC conversion circuit, wherein the AC side of the DC / AC conversion circuit is connected to the AC side of the power transmission device, and the DC side of the DC / AC conversion circuit is connected to the corresponding bus branch through the DC / DC conversion circuit. Alternatively, a DC / DC converter circuit, wherein the bus branch is connected to each of the corresponding transmission branches through the DC / DC converter circuit.
12. The power transmission device according to claim 9, characterized in that, The power transmission device further includes: at least one DC switching module; The DC switch module is connected between the bus branch and each of the excitation fuses connected to the bus branch.
13. A power conversion system, characterized in that, include: The controller and at least one power transmission device as described in any one of claims 8 to 12; wherein, The power transmission device is controlled by the controller.