Multi-port hybrid direct current circuit breaker and control method and control device thereof

Abstract

The invention provides a multi-port hybrid direct-current circuit breaker and a control method and device thereof. The circuit breaker comprises a through-flow branch, a transfer branch, an energy consumption branch and an isolation branch. A quick mechanical switch is mounted on the through-flow branch; the transfer branch is connected in series with a plurality of one-way on-off sub-modules, and each one-way on-off sub-module is internally provided with a power electronic switch and is provided with a buffer branch; a plurality of groups of first overvoltage protection elements are connected in series and in parallel on the energy consumption branch; the isolation branch is connected in series with a plurality of power electronic devices and is connected in parallel with an energy storage unit. According to the structure, the control strategy is improved, the requirement for the transfer branch is reduced, the transfer branch does not need to have the two-way breaking capacity and only has the one-way breaking capacity, the requirement for removing faults of the circuit breaker under the full working condition can be met, an anti-parallel diode structure or a diode bridge arm module does not need to be arranged, the corresponding cost is saved, and the working efficiency is improved. And the problems of stray inductance increase and the like caused by the increase of commutation paths are also reduced.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a multi-port hybrid DC circuit breaker and a control method and a control device thereof. Background Art

[0002] Flexible DC grid is the best solution to achieve friendly access and flexible consumption of large-scale renewable clean energy. In particular, the grid structure that adopts new technologies, equipment and targeted designs can be expected to meet the needs of future energy structure changes and have a profound impact on the energy distribution pattern. It is foreseeable that in the future, flexible DC grid will be an important technical means for the country to build a new power system with new energy as the main body.

[0003] In actual work, the flexible DC grid has low impedance characteristics, which leads to a current rise rate of up to kA / ms when a fault occurs on its DC side. The fault current can reach tens of kiloamperes within a few milliseconds, which will damage the converter station and vulnerable equipment in the DC grid. At present, the main means to solve the above problems is to install high-voltage DC circuit breakers, which can quickly and stably clear DC faults and are the core equipment for DC system construction.

[0004] In the existing power grid design, the meshed DC grid usually contains multiple DC buses. In order to ensure that a fault occurs at any position of the DC line and is reliably isolated, DC circuit breakers need to be installed on all incoming and outgoing lines of the DC bus. However, hybrid DC circuit breakers require a large number of fully controlled power electronic devices to be connected in series to withstand a breaking voltage of hundreds of kilovolts, resulting in a high cost of the devices, which restricts the large-scale promotion and application of DC circuit breakers in DC grids.

[0005] Therefore, the existing multi-port hybrid DC circuit breaker design generally integrates the transfer branches of the two-port DC circuit breakers originally connected to the same DC bus, and shares the expensive main disconnect switch to interrupt the fault current. This can not only reduce the number of two-port DC circuit breakers in the DC power grid, reduce the total cost of the circuit breakers, and reduce the footprint, but also facilitate the large-scale use of DC circuit breakers, and promote the rapid development of flexible DC power grid interconnection systems based on flexible DC transmission technology.

[0006] However, in order to meet the fault clearing capability under various working conditions, the power electronic switch on the transfer branch of the common multi-port hybrid DC circuit breaker needs to have a bidirectional current breaking capability. Initially, the anti-parallel structure of the power electronic switch was used to achieve bidirectional current breaking. In order to reduce the number and cost of high-power breaking power electronic devices, the current mainstream form adopts a diode bridge module structure, which can reduce the number of power electronic switch devices by half. Correspondingly, it is necessary to add cheaper diodes, that is, under the premise of retaining the same function, the use of a diode bridge module can reduce the overall cost. Therefore, the transfer branch structure of the existing common multi-port hybrid DC circuit breaker has no change compared with the previous common two-port design, but only adds an isolation branch and a flow branch to integrate multiple two-port hybrid circuit breakers, thereby realizing fault clearing and isolation of multiple lines. However, the transfer branch of the existing multi-port hybrid DC circuit breaker still inevitably uses a large number of diodes. Although the cost is lower than that of the original anti-parallel structure, it is still high, accounting for about half of the total cost of the circuit breaker, and the diode bridge structure will also increase the commutation path, which will bring about problems such as increased stray inductance.

[0007] In summary, it is still necessary to improve the design structure of the multi-port hybrid DC circuit breaker and combine it with an adaptive control method to achieve the same function while solving the cost problem. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a multi-port hybrid DC circuit breaker with a simplified structure, low cost and the same functions.

[0009] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0010] In one aspect, the present invention provides a multi-port hybrid circuit breaker, which includes a flow branch, a transfer branch, an energy consumption branch and an isolation branch; a fast mechanical switch is installed on the flow branch; a plurality of power electronic switches are connected in series and parallel on the transfer branch;

[0011] The transfer branch is connected in series with a plurality of one-way breaking submodules, each of which is provided with the power electronic switch; the transfer branch is also provided with a buffer branch, and the buffer branch is provided with an energy storage device or an energy consumption device;

[0012] The energy consumption branch has a plurality of groups of first overvoltage protection elements connected in series and parallel;

[0013] A plurality of power electronic devices are connected in series on the isolation branch, and energy storage units are connected in parallel at both ends of at least one of the power electronic devices;

[0014] The multi-port hybrid DC circuit breaker further comprises a control module, and the control module is used to control the opening and closing of the fast mechanical switch and / or the unidirectional breaking submodule.

[0015] Optionally, at least one insulated gate bipolar transistor is provided in the unidirectional disconnecting submodule.

[0016] Optionally, in each of the unidirectional disconnecting submodules, the number of the insulated gate bipolar transistors is greater than or equal to 2;

[0017] In the unidirectional disconnecting submodule, a plurality of the insulated gate bipolar transistors are connected in parallel.

[0018] Optionally, the buffer branch is provided in the unidirectional disconnecting submodule, and the insulated gate bipolar transistor is connected in parallel with the buffer branch.

[0019] Optionally, the buffer branch is an H-bridge structure, and a resistor, a capacitor and a diode are provided on the bridge arm;

[0020] The buffer branch is also connected in parallel with a second overvoltage protection element;

[0021] The second overvoltage protection element is a metal oxide varistor.

[0022] Optionally, the first overvoltage protection element is a lightning arrester valve plate.

[0023] Optionally, the arrester valve plate is a metal oxide varistor.

[0024] Optionally, the energy storage unit is connected in parallel to both ends of at least one of the power electronic devices on the isolation branch;

[0025] The energy storage unit is a charging capacitor.

[0026] On the other hand, the present invention further provides a control method based on the above multi-port hybrid DC circuit breaker;

[0027] The steps include:

[0028] After receiving the protection action command, the multi-port hybrid circuit breaker opens the fast mechanical switch of the current-carrying branch corresponding to the non-fault line;

[0029] After the fast mechanical switch of the current-carrying branch corresponding to the non-fault line reaches the specified opening distance, the transfer branch and the isolation branch corresponding to the non-fault line are turned on;

[0030] When the fault current and the commutation current are superimposed on the fast mechanical switch of the current-carrying branch corresponding to the non-fault line and cross zero, the arc of the fast mechanical switch of the current-carrying branch corresponding to the non-fault line is extinguished and disconnected;

[0031] When the arc of the fast mechanical switch of the current-carrying branch corresponding to the non-fault line is extinguished and disconnected, all the one-way breaking submodules of the transfer branch are locked, and the fault current is transferred to the buffer branch;

[0032] When the voltage of the transfer branch rises to the action threshold voltage of the energy consumption branch, the fault current is commutated to the energy consumption branch;

[0033] When the fault current decays to zero, the isolation branch is turned off.

[0034] Optionally, when the fault does not occur on the DC bus, and when the fault current in the line decays to zero, the fast mechanical switch of the current-carrying branch corresponding to the faulty line is opened without arcing;

[0035] The control method further comprises the following steps:

[0036] Close the fast mechanical switch of the current-carrying branch corresponding to the non-fault line.

[0037] On the other hand, the present invention provides a control device based on the above multi-port hybrid DC circuit breaker and control method, including: an instruction notification module, a switch control module, a signal acquisition module and a commutation control module;

[0038] The instruction notification module is used to: notify the multi-port hybrid circuit breaker of the protection action instruction;

[0039] The switch control module is used to: control the disconnection of the fast mechanical switch, turn on or off the isolation branch, and lock the one-way disconnection submodule;

[0040] The signal acquisition module is used to: collect the opening distance and current of the fast mechanical switch, the voltage of the transfer branch, and the current in the line;

[0041] The commutation control module is used to: transfer the fault current to the buffer branch, and commutate the fault current to the energy consumption branch.

[0042] Optionally, the switch control module is further used to: control the closing of the fast mechanical switch.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The structure of the present invention can reduce the requirements for the transfer branch by improving the control strategy of the multi-port hybrid DC circuit breaker. The transfer branch does not need to have a bidirectional breaking capability, and only a unidirectional breaking capability can meet the requirement of the circuit breaker to cut off the fault under all working conditions. There is no need to set an anti-parallel diode structure or a diode bridge arm module, which saves corresponding costs and reduces problems such as increased stray inductance caused by increasing the commutation path. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] 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 will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0046] Figure 1 This is a schematic circuit diagram of the circuit breaker of the present invention;

[0047] Figure 2 This is a flow chart of the control method of the present invention;

[0048] FIG3( a ) is a schematic diagram of the current at time t0 in a specific process;

[0049] FIG3( b ) is a schematic diagram of the current at time t2 in the specific process;

[0050] FIG3(c) is a schematic diagram of the current at time t3 in the specific process;

[0051] FIG3( d ) is a schematic diagram of the current at time t5 in the specific process;

[0052] FIG3( e ) is a schematic diagram of the current at time t7 in the specific process.

[0053] In the figure: 1. Flow branch; 2. Transfer branch; 3. Energy consumption path; 4. Isolation branch. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0056] In the description of the present invention, “plurality” means two or more than two, unless otherwise clearly and specifically defined.

[0057] It is worth noting that the methods used in the present invention are all conventional methods unless otherwise specified; the raw materials and devices used are all conventional commercially available products, and their sources are not specifically limited unless otherwise specified.

[0058] like Figure 1 As shown, this embodiment provides a multi-port hybrid DC circuit breaker, which, compared with the existing design, also includes a current-passing branch 1, a transfer branch 2, an energy-consuming branch 3 and an isolation branch 4 (the marks represent the contents indicated in the dotted box in the figure and related contents).

[0059] Specifically, this embodiment is described by taking four lines and one DC bus as an example, so there are four flow branches 1 in this embodiment, which are respectively connected to the corresponding lines (Line1, Line2, Line3, Line4) and the DC bus. A fast mechanical switch (abbreviated as MS, respectively: MS1, MS2, MS3, MS4) is also installed on each flow branch 1. A plurality of power electronic switch modules are connected in series and parallel on the transfer branch 2.

[0060] Compared with the prior art, the present embodiment has a total of one transfer branch 2, one end of which is connected to the DC bus, and the other end is connected to each isolation branch 4. A plurality of unidirectional disconnection submodules are connected in series on the transfer branch 2, so that the transfer branch 2 structure formed by them is a unidirectional disconnection structure. At least one power electronic switch is provided in each unidirectional disconnection submodule; optionally, the power electronic switch of the unidirectional disconnection submodule is an insulated gate bipolar transistor (hereinafter referred to as: IGBT), and each unidirectional disconnection submodule of the present embodiment is provided with two IGBTs, and a parallel structure is adopted.

[0061] The transfer branch 2 is also provided with a buffer branch for temporarily taking over the fault current, which is provided with an energy storage device or an energy consumption device; optionally, Figure 1 As shown, a buffer branch is connected in parallel in each unidirectional disconnecting submodule, and the main body of the buffer branch is an H-bridge structure, and a resistor, a capacitor and a diode are arranged on the bridge arm. Specifically, a resistor R1 and a diode are connected in parallel in the upper bridge arm of the buffer branch, and a resistor R2 and a capacitor are connected in parallel in the lower bridge arm. A second overvoltage protection element is also connected in parallel on each buffer branch, and the second overvoltage protection element of this embodiment is selected as a metal oxide varistor.

[0062] There is a total of one energy consumption branch 3, which is connected in parallel at both ends of the transfer branch 2, and multiple groups of first overvoltage protection elements are connected in series and parallel on it; optionally, the first overvoltage protection element is a lightning arrester valve plate, and the lightning arrester valve plate of this embodiment is selected as a metal oxide varistor (MOV).

[0063] The number of isolation branches 4 is consistent with that of lines, so there are four isolation branches 4 in this embodiment, one end of which is connected to the line, and the other end is connected to the transfer branch 2. A plurality of power electronic devices are connected in series to the isolation branch 4, such as: a thyristor is connected in series to the side close to the transfer branch 2, and then diodes are connected in series in sequence, and energy storage units are connected in parallel to some diodes at the end of the line side. The energy storage unit in this embodiment is a charging capacitor to form a negative voltage source (NVS).

[0064] Optionally, a control module is also provided in this embodiment, which is used to control the on and off of the fast mechanical switch and the on and off of the electronic power switch and other components in the one-way breaking submodule, so as to achieve the corresponding functions. However, it should be noted that since the control module of the DC circuit breaker is in various forms, it can be understood that the control module of this embodiment is not limited to the internal integration of the intelligent circuit breaker, but can also be integrated with a matching controller / device, or the control module can be integrated in the lower computer connected to the control port.

[0065] Based on the above multi-port hybrid DC circuit breaker, this embodiment also provides a Figure 2 The control method shown, specifically, needs to be controlled in two categories according to the short-circuit fault type.

[0066] First, take the DC busbar single-pole metallic ground short circuit fault as an example:

[0067] When a short-circuit fault occurs on the bus, it is recorded as time t0. At this time, a metallic grounding fault occurs on the DC bus, and the submodule capacitors in all converter stations connected to it are discharged rapidly. The short-circuit current increases at a rate of kA / ms and is all injected into the bus short-circuit point. In this case, all lines can be regarded as faulty lines.

[0068] Furthermore, for the sake of convenience of explanation, the following is a description of the control method based on the demonstration timing in a specific embodiment and in the order of steps represented by the S sequence. Technical personnel in this field can adjust the order of steps as needed (change the order or perform them simultaneously), and this should not be understood as a limiting condition.

[0069] The control method comprises the following steps:

[0070] S1. At time t1, after receiving the protection action instruction, the multi-port hybrid circuit breaker of this embodiment opens the fast mechanical switches of the current-carrying branches corresponding to the non-fault lines, that is, all the fast mechanical switches MS1-MS4.

[0071] S2. At time t2, the fast mechanical switches of each current-carrying branch reach the specified opening distance, and simultaneously turn on all IGBTs on the transfer branch and all thyristors on the isolation branch to form a capacitor discharge circuit.

[0072] S3. At time t3, when the fault current and the commutation current are superimposed on the fast mechanical switch of the flow branch and cross zero, the arc of the fast mechanical switch is extinguished and disconnected; the short-circuit current is completely commutated from the flow branch to the transfer branch and flows to the fault point. At this time, the fault is still not isolated, and the fault current continues to rise at the original rate; at the same time, the fault current reversely charges the capacitor until the capacitor voltage reversely crosses zero and is short-circuited by the diode.

[0073] S4. At time t4, all IGBTs on the transfer branch are locked at the same time, and the fault current is transferred to the buffer branch. At this time, the voltage of the transfer branch rises rapidly.

[0074] S5. At time t5, when the voltage of the transfer branch rises to the action threshold voltage of the MOV of the energy consumption branch, the MOV changes from high impedance to low impedance, and the fault current is commutated to the energy consumption branch. The MOV quickly establishes a transient voltage higher than the DC system voltage, and the fault current begins to decrease under this effect.

[0075] S6. At time t6, the fault current decays to zero, and the thyristors of all isolated branches are naturally turned off. At this point, the bus fault is successfully isolated.

[0076] Secondly, combined Figure 3(a)-Figure 3(e) As shown in the figure, taking the single-pole metallic ground short circuit fault of Line 1 in the system as an example, the control of non-DC bus fault is explained. The specific example is:

[0077] When a short circuit fault occurs on Line 1, recorded as time t0, as shown in Figure 3(a), the submodule capacitors in all converter stations connected to it are discharged rapidly, and the short circuit current increases at a rate of kA / ms and is fully injected into the short circuit point.

[0078] The control method comprises the following steps:

[0079] S1. At time t1, after receiving the protection action instruction, the multi-port hybrid circuit breaker of this embodiment opens the fast mechanical switches of the current-carrying branches corresponding to the non-fault lines, namely, the fast mechanical switches MS2-MS4.

[0080] S2. At time t2, the fast mechanical switches of the current-carrying branches corresponding to the non-fault lines reach the specified opening distance, and simultaneously turn on all IGBTs on the transfer branches and the thyristors on the isolation branches corresponding to the non-fault lines to form a capacitor discharge circuit, as shown in Figure 3(b).

[0081] S3, at time t3, when the fault current and the commutation current are superimposed on the fast mechanical switch of the flow branch and cross zero, the arc of the fast mechanical switch is extinguished and disconnected; the short-circuit current is completely commutated from the flow branch to the transfer branch, and flows to the fault point through the fast mechanical switch of the fault line, as shown in Figure 3 (c). At this time, the fault is still not isolated, and the fault current continues to rise at the original rate. At the same time, the fault current reversely charges the capacitor until the capacitor voltage reversely crosses zero and is short-circuited by the diode.

[0082] S4. At time t4, all IGBTs on the transfer branch are locked at the same time, and the fault current is transferred to the buffer branch. At this time, the voltage of the transfer branch rises rapidly.

[0083] S5. At time t5, when the voltage of the transfer branch rises to the action threshold voltage of the energy consumption branch MOV, the MOV changes from high impedance to low impedance, and the fault current is commutated to the energy consumption branch. As shown in Figure 3(d), the MOV quickly establishes a transient voltage higher than the DC system voltage, and the fault current begins to decrease under this action.

[0084] S6. At time t6, when the fault current decays to zero, the fast mechanical switch MS1 of the current-carrying branch corresponding to the fault line is opened without arcing, and at the same time, the thyristors of all isolation branches are naturally turned off.

[0085] S7. At time t7, the fast mechanical switch of the current-carrying branch corresponding to the non-fault line is closed, and the non-fault line gradually resumes normal operation, as shown in Figure 3(e).

[0086] It should be understood that the "moment" mentioned in the above embodiment is only used to describe that the timing of the specific actions of the steps is arranged in chronological order, and the specific moment is determined according to the actual working conditions and the detection signal corresponding to the moment. It is not a simple static value. It can be a fixed value after verification, or it can be a follow-up value generated by the detection signal. It cannot be understood as a limiting condition of the present invention.

[0087] On the other hand, based on the above-mentioned multi-port hybrid DC circuit breaker and control method, this embodiment also provides a matching control device, which mainly includes: an instruction notification module, a switch control module, a signal acquisition module and a commutation control module.

[0088] Among them, the instruction notification module is used to: notify the multi-port hybrid circuit breaker of the protection action instruction; optionally, the switch control module is also used to: control the closing of the fast mechanical switch.

[0089] The switch control module is used to: control the disconnection of the fast mechanical switch, turn on or off the isolation branch, and lock the one-way disconnection submodule.

[0090] The signal acquisition module is used to collect the opening distance and current of the fast mechanical switch, the voltage of the transfer branch, and the current in the line.

[0091] The commutation control module is used to transfer the fault current to the buffer branch and commutate the fault current to the energy consumption branch.

[0092] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A multi-port hybrid DC circuit breaker, comprising a flow branch, a transfer branch, an energy consumption branch and an isolation branch; a fast mechanical switch is installed on the flow branch; and a plurality of power electronic switch modules are connected in series and parallel on the transfer branch; Features: A plurality of one-way breaking submodules are connected in series on the transfer branch, each of which is provided with the power electronic switch and is configured with a buffer branch; The energy consumption branch has a plurality of groups of first overvoltage protection elements connected in series and parallel; A plurality of power electronic devices are connected in series on the isolation branch, and energy storage units are connected in parallel at both ends of at least one of the power electronic devices; The multi-port hybrid DC circuit breaker further comprises a control module, and the control module is used to control the opening and closing of the fast mechanical switch and / or the unidirectional breaking submodule.

2. The multi-port hybrid DC circuit breaker according to claim 1, characterized in that: At least one insulated gate bipolar transistor is arranged in the unidirectional disconnecting submodule.

3. The multi-port hybrid DC circuit breaker according to claim 2, characterized in that: In each of the unidirectional disconnecting submodules, the number of the insulated gate bipolar transistors is greater than or equal to 2; In the unidirectional disconnecting submodule, a plurality of the insulated gate bipolar transistors are connected in parallel.

4. The multi-port hybrid DC circuit breaker according to claim 2 or 3, characterized in that: The buffer branch is provided in the unidirectional disconnecting submodule, and the insulated gate bipolar transistor is connected in parallel with the buffer branch.

5. The multi-port hybrid DC circuit breaker according to claim 4, characterized in that: The buffer branch is an H-bridge structure, with a resistor, a capacitor and a diode provided on the bridge arm; The buffer branch is also connected in parallel with a second overvoltage protection element; The second overvoltage protection element is a metal oxide varistor.

6. The multi-port hybrid DC circuit breaker according to claim 1, characterized in that: The first overvoltage protection element is a lightning arrester valve plate.

7. The multi-port hybrid DC circuit breaker according to claim 6, characterized in that: The arrester valve plate is a metal oxide varistor.

8. The multi-port hybrid DC circuit breaker according to claim 1, characterized in that: The energy storage unit is connected in parallel at both ends of at least one of the power electronic devices on the isolation branch; The energy storage unit is a charging capacitor.

9. A multi-port hybrid DC circuit breaker control method, characterized in that: The method comprises the following steps: after receiving the protection action instruction, the multi-port hybrid circuit breaker opens the fast mechanical switch of the current-carrying branch corresponding to the non-fault line; After the fast mechanical switch of the current-carrying branch corresponding to the non-fault line reaches the specified opening distance, the transfer branch and the isolation branch corresponding to the non-fault line are turned on; When the fault current and the commutation current are superimposed on the fast mechanical switch of the current-carrying branch corresponding to the non-fault line and cross zero, the arc of the fast mechanical switch of the current-carrying branch corresponding to the non-fault line is extinguished and disconnected; When the arc of the fast mechanical switch of the current-carrying branch corresponding to the non-fault line is extinguished and disconnected, all the one-way breaking submodules of the transfer branch are locked, and the fault current is transferred to the buffer branch; When the voltage of the transfer branch rises to the action threshold voltage of the energy consumption branch, the fault current is commutated to the energy consumption branch; When the fault current in the line decays to zero, the isolation branch is shut down.

10. The multi-port hybrid DC circuit breaker control method according to claim 9, characterized in that: When the fault does not occur on the DC bus, and when the fault current in the line decays to zero, the fast mechanical switch of the current-carrying branch corresponding to the fault line is opened without arcing; The control method further comprises the following steps: Close the fast mechanical switch of the current-carrying branch corresponding to the non-fault line.

11. A multi-port hybrid DC circuit breaker control device, characterized in that: It includes a command notification module, a switch control module, a signal acquisition module and a commutation control module; The instruction notification module is used to: notify the multi-port hybrid circuit breaker of the protection action instruction; The switch control module is used to: control the disconnection of the fast mechanical switch, turn on or off the isolation branch, and lock the one-way disconnection submodule; The signal acquisition module is used to: collect the opening distance and current of the fast mechanical switch, the voltage of the transfer branch, and the current in the line; The commutation control module is used to: transfer the fault current to the buffer branch, and commutate the fault current to the energy consumption branch.

12. The multi-port hybrid DC circuit breaker control device according to claim 11, characterized in that: The switch control module is also used to control the fast mechanical switch to close.

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