A multi-port hybrid DC circuit breaker and a control method and control device thereof

Abstract

The application provides a multi-port hybrid DC circuit breaker and a control method and a control device thereof, the circuit breaker comprising a through-flow branch, a transfer branch, an energy consumption branch and an isolation branch. A fast mechanical switch is installed on the through-flow branch; a plurality of one-way breaking sub-modules are connected in series on the transfer branch, each one-way breaking sub-module being provided with a power electronic switch and being provided with a buffer branch; a plurality of groups of first overvoltage protection elements are connected in series and parallel on the energy consumption branch; a plurality of power electronic devices are connected in series on the isolation branch, and an energy storage unit is connected in parallel. The structure of the application reduces the requirement for the transfer branch by improving the control strategy, and the transfer branch does not need to have bidirectional breaking capacity, but only needs to have unidirectional breaking capacity to meet the requirement of the circuit breaker for cutting off faults under all working conditions, so that a reverse-parallel diode structure or a diode bridge arm module does not need to be arranged, the corresponding cost is saved, and problems such as an increase in stray inductance caused by an increase in the commutation path are 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 grids are an optimal solution for enabling the friendly integration and flexible consumption of large-scale renewable clean energy. In particular, grid structures designed with new technologies, equipment, and targeted designs are expected to meet the demands of future energy mix changes and have a profound impact on energy distribution patterns. It is foreseeable that flexible DC grids will be a key technological tool in China's efforts to build a new power system dominated by new energy.

[0003] In practice, the low impedance of flexible DC grids results in current rise rates as high as kA / ms during DC-side faults. Fault currents can reach tens of kiloamperes within milliseconds, damaging converter stations and vulnerable equipment within the DC grid. Currently, the primary solution to this problem is the installation of high-voltage DC circuit breakers, which are core equipment for DC system construction and can quickly and reliably clear DC faults.

[0004] In existing grid designs, meshed DC grids typically consist of multiple DC busbars. To ensure reliable isolation of faults anywhere on the DC line, DC circuit breakers must be installed on all incoming and outgoing DC busbars. However, hybrid DC circuit breakers require a large number of fully controlled power electronic components connected in series to withstand interruption voltages of hundreds of kilovolts, resulting in high component costs and hindering the large-scale promotion and application of DC circuit breakers in DC grids.

[0005] Therefore, the existing design of multi-port hybrid DC circuit breakers 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 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 grid interconnection systems based on flexible DC transmission technology.

[0006] However, to meet the requirements for fault clearing under various operating conditions, the power electronic switches in the transfer branches of currently common multi-port hybrid DC circuit breakers must possess bidirectional current interruption capabilities. Initially, bidirectional current interruption was achieved using an anti-parallel structure with power electronic switches. To reduce the number and cost of high-power interruption power electronic devices, the current mainstream approach uses a diode bridge module structure, which can halve the number of power electronic switch devices. This, in turn, requires the addition of relatively inexpensive diodes. This means that while retaining the same functionality, the use of a diode bridge module can reduce overall costs. Therefore, the transfer branch structure of a common multi-port hybrid DC circuit breaker remains unchanged from the previously common two-port design. It simply adds an isolation branch and a current-passing branch to integrate multiple two-port hybrid circuit breakers, thereby achieving fault clearing and isolation for multiple lines. However, the transfer branches of existing multi-port hybrid DC circuit breakers still inevitably use a large number of diodes. While this cost is lower than the original anti-parallel structure, it remains high, accounting for approximately half of the total cost of the circuit breaker. Furthermore, the diode bridge structure also increases the commutation path, leading to problems such as increased stray inductance.

[0007] In summary, the design structure of the multi-port hybrid DC circuit breaker needs to be improved, and when combined with an adapted control method to achieve the same function, the cost problem can also be solved. 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 object, 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; and 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 disconnecting 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 is connected in series and parallel with a plurality of first overvoltage protection elements;

[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 includes a control module, which is used to control the opening and closing of the fast mechanical switch and / or the one-way breaking submodule.

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

[0016] Optionally, in each of the unidirectional disconnect sub-modules, the number of the insulated gate bipolar transistors is greater than or equal to 2;

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

[0018] Optionally, the buffer branch is provided in the unidirectional disconnect 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, with a resistor, a capacitor and a diode provided on the bridge arm;

[0020] A second overvoltage protection element is also connected in parallel to the buffer branch;

[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-mentioned 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 a 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 overlap and cross zero on the fast mechanical switch of the current-carrying branch corresponding to the non-fault line, 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 corresponding to the through-flow branch of the non-fault line is extinguished and disconnected, all the unidirectional breaking sub-modules 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 corresponding to the through-flow branch of the fault line is opened without arc;

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

[0036] The fast mechanical switch corresponding to the through-flow branch of the non-fault line is closed.

[0037] In still another aspect, the present application provides a control device based on the above-mentioned multi-port hybrid DC circuit breaker and control method, comprising: an instruction notification module, a switch control module, a signal acquisition module and a commutation control module;

[0038] The instruction notification module is configured to notify a multi-port hybrid circuit breaker protection action instruction.

[0039] The switch control module is configured to control the disconnection of the fast mechanical switch, the conduction or turn-off of the isolation branch, and the locking of the unidirectional breaking sub-module.

[0040] The signal acquisition module is configured to acquire 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 configured 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 configured to control the closing of the fast mechanical switch.

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

[0044] The structure of the present application improves the control strategy of the multi-port hybrid DC circuit breaker, which can reduce the requirements for the transfer branch. The transfer branch does not need to have bidirectional breaking capability, but only needs to have unidirectional breaking capability to meet the requirements of the circuit breaker for cutting off faults under all working conditions. The present application does not need to set a reverse-parallel diode structure or a diode bridge arm module, thereby saving the corresponding cost and reducing the problem of increased stray inductance caused by the added commutation path. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. 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 any creative work.

[0046] Figure 1 This is a simplified 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] Figure 3(a) is a schematic diagram of the current at time t0 in the specific process;

[0049] Figure 3(b) is a schematic diagram of the current at time t2 in the specific process;

[0050] Figure 3(c) is a schematic diagram of the current at time t3 in the specific process;

[0051] Figure 3(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] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, 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 only 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 making creative efforts shall fall 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, it does not need to be further defined or explained in subsequent drawings.

[0056] In the description of the present invention, “plurality” means two or more, unless otherwise clearly 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 branch 1, a transfer branch 2, an energy consumption 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 uses four lines and a DC bus as an example. Therefore, there are four flow branches 1, each connecting the corresponding lines (Line 1, Line 2, Line 3, and Line 4) and the DC bus. A fast mechanical switch (MS, MS1, MS2, MS3, and MS4) is also installed on each flow branch 1. Multiple power electronic switch modules are connected in series and parallel on the transfer branch 2.

[0060] Compared to the prior art, this embodiment has a single transfer branch 2, one end of which is connected to the DC bus and the other end is connected to each isolation branch 4. Multiple unidirectional disconnect submodules are connected in series to the transfer branch 2, resulting in a unidirectional disconnect structure. Each unidirectional disconnect submodule is equipped with at least one power electronic switch; optionally, the power electronic switch of the unidirectional disconnect submodule is an insulated gate bipolar transistor (IGBT). In this embodiment, each unidirectional disconnect submodule is equipped with two IGBTs, which are connected in parallel.

[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 to each unidirectional disconnect submodule. The main body of the buffer branch is an H-bridge structure, with resistors, capacitors, and diodes installed in the bridge arms. Specifically, resistor R1 and a diode are connected in parallel to the upper bridge arm of the buffer branch, and resistor R2 and a capacitor are connected in parallel to the lower bridge arm. Each buffer branch is also connected in parallel to a second overvoltage protection element. In this embodiment, the second overvoltage protection element is a metal oxide varistor.

[0062] There is 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 matches the number of lines, so in this embodiment, there are four isolation branches 4, one end of which is connected to the line and the other end is connected to the transfer branch 2. Multiple power electronic devices are connected in series to the isolation branches 4, such as a thyristor connected in series on the side close to the transfer branch 2, followed by diodes connected in series. Energy storage units are connected in parallel to some of the diodes at the end close to the line. In this embodiment, the energy storage units are charging capacitors, forming a negative voltage source (NVS).

[0064] Optionally, this embodiment further includes a control module for controlling the on / off of the fast mechanical switch and the opening and closing of components such as the electronic power switch in the one-way disconnect submodule, thereby achieving corresponding functions. However, it should be noted that, since control modules for DC circuit breakers can take various forms, it is understood that the control module of this embodiment is not limited to being integrated within the intelligent circuit breaker. It can also be integrated with a supporting controller / device, or integrated into a 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 divided into two categories for control 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 busbar short-circuit fault occurs, recorded as time t0, a metallic ground fault occurs on the DC busbar. The submodule capacitors in all the converter stations connected to it discharge rapidly, and the short-circuit current increases at a rate of kA / ms and is fully injected into the busbar short-circuit point. In this case, all lines can be regarded as fault lines.

[0068] Furthermore, for the sake of convenience, 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. Those skilled in the art 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 includes 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 overlap and cross zero on the fast mechanical switch of the flow branch, 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 t4, all IGBTs on the transfer branch are simultaneously blocked, the fault current is transferred to the buffer branch, at this time, the voltage of the transfer branch rises rapidly.

[0074] S5, at t5, when the voltage of the transfer branch rises to the action threshold voltage of the energy dissipation branch MOV, the MOV changes from high impedance to low impedance, the fault current commutates to the energy dissipation branch, the MOV rapidly establishes a transient voltage higher than the DC system voltage, and the fault current begins to decrease under the action of the MOV.

[0075] S6, at t6, the fault current decays to zero, and the thyristors of all isolation branches are naturally turned off, and thus the bus fault is successfully isolated.

[0076] Secondly, combined with Figure 3(a)-Figure 3(e) As shown in FIG. 2, taking a single-pole metallic short-circuit fault of a line Line1 in the system as an example, the control of the non-DC bus fault is described in detail.

[0077] When the line Line1 has a short-circuit fault, denoted as t0, as shown in FIG. 3(a), the capacitors of all sub-modules in the converter stations connected to the line Line1 rapidly discharge, and the short-circuit current rises at a rate of kA / ms and is injected into the short-circuit point.

[0078] The control method comprises the following steps.

[0079] S1, at t1, after receiving a protection action instruction, the multi-port hybrid circuit breaker of the embodiment pulls open the fast mechanical switches MS2-MS4 of the through-flow branches corresponding to the non-fault lines.

[0080] S2, at t2, the fast mechanical switches of the through-flow branches corresponding to the non-fault lines reach a specified opening distance, all IGBTs on the transfer branches are turned on, and the thyristors on the isolation branches corresponding to the non-fault lines are turned on, to form a capacitor discharge loop, as shown in FIG. 3(b).

[0081] S3, at t3, when the fault current and the converter current superimpose zero on the fast mechanical switches of the through-flow branches, the arc of the fast mechanical switches is extinguished and opened; the short-circuit current is completely commutated from the through-flow branches to the transfer branches, and flows to the fault point through the fast mechanical switches of the fault lines, as shown in FIG. 3(c), at this time, the fault is not yet isolated, and the fault current continues to rise at the original rate. At the same time, the fault current reversely charges the capacitors, until the capacitor voltage reversely crosses zero and is short-circuited by the diode.

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

[0083] At time t5, when the voltage of the transfer branch rises to the operating threshold voltage of the MOV in the energy-consuming branch, the MOV changes from high impedance to low impedance, and the fault current is commutated to the energy-consuming 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 the isolation branches are naturally turned off.

[0085] S7. At time t7, the fast mechanical switch of the current-carrying branch of 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. 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 further 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] 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 disconnect sub-module.

[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; the flow branch is equipped with a fast mechanical switch; and the transfer branch is equipped with multiple power electronic switch modules connected in series and parallel. Its characteristics are: 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 and is configured with a buffer branch; The energy consumption branch is connected in series and parallel with a plurality of first overvoltage protection elements; A plurality of power electronic devices are connected in series on the isolation branch, and an energy storage unit is connected in parallel at both ends of at least one of the power electronic devices; The multi-port hybrid DC circuit breaker further includes a control module, which is used to control the opening and closing of the fast mechanical switch and / or the one-way breaking submodule; The multi-port hybrid DC circuit breaker control method includes the following steps: When the fault does not occur on the DC bus, the multi-port hybrid circuit breaker opens the fast mechanical switch of the current-carrying branch corresponding to the non-fault line after receiving the protection action command; After the fast mechanical switch of the current-carrying branch corresponding to the non-fault line reaches a 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 overlap and cross zero on the fast mechanical switch of the corresponding flow branch of the non-fault line, the arc of the fast mechanical switch of the corresponding flow branch of the non-fault line is extinguished and disconnected, and the short-circuit current is completely commutated from the flow branch of the non-fault line to the transfer branch, and flows to the fault point through the fast mechanical switch of the fault line; 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 sub-modules 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 fast mechanical switch of the current-carrying branch corresponding to the fault line is opened without arcing, and at the same time, the thyristors of all the isolation branches are naturally turned off; Close the fast mechanical switch of the current-carrying branch corresponding to the non-fault line, and the non-fault line will gradually resume normal operation.

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

3. The multi-port hybrid DC circuit breaker according to claim 2, characterized in that: In each of the unidirectional disconnect sub-modules, the number of the insulated gate bipolar transistors is greater than or equal to 2; In the unidirectional disconnect 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 disconnect 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 resistors, capacitors and diodes provided on the bridge arms; A second overvoltage protection element is also connected in parallel to the buffer branch; 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 lightning 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 to 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 device, characterized in that: The multi-port hybrid DC circuit breaker according to any one of claims 1 to 8 comprises an instruction 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 disconnect 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.

10. The multi-port hybrid DC circuit breaker control device according to claim 9, characterized in that: The switch control module is further used to control the fast mechanical switch to close.

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