A Multifunctional Multi-Port Hybrid DC Circuit Breaker and Control Method

Abstract

A multi-functional multi-port hybrid DC circuit breaker and control method provided by the present invention. The circuit breaker includes: a power flow control module, a plurality of current-carrying modules, a current-limiting module, an energy-consuming module, a breaking module, and a plurality of selection modules. One end of the power flow control module is connected to the DC bus wiring port, and the other end is connected to one end of each current-carrying module. The other end of each current-carrying module is connected to each DC line wiring port. The DC bus wiring port and the DC line wiring port are arranged in one-to-one correspondence; one end of each selection module is connected to its corresponding DC line, and the other end is connected to one end of the current-limiting module; the other end of the current-limiting module is respectively connected to one end of the energy-consuming module and one end of the breaking module; the other end of the energy-consuming module and the other end of the breaking module are connected to the DC bus. By implementing the present invention, the equipment investment of the DC circuit breaker is greatly reduced, and it has the power flow control ability, which is beneficial to promoting the development of multi-terminal and DC power grids.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and particularly to a multi-functional multi-port hybrid DC circuit breaker and a control method therefor. Background Art

[0002] The high-voltage DC circuit breaker is one of the core devices for constructing multi-terminal and DC power grids, and its technical economy directly affects the flexibility and universality of the application of DC power grids. With the large-scale development of renewable energy such as wind and light, the transmission capacity and application scale of DC power grids will continue to increase, the grid structure will become increasingly complex, and the large-scale application will put forward higher requirements for the technical economy of high-voltage DC circuit breakers.

[0003] Currently, there are mainly two technical routes for high-voltage DC circuit breakers: hybrid and mechanical. The mechanical scheme has bottleneck problems such as long breaking time for small currents and difficulty in rapid reclosing, which limits the improvement of the breaking performance of the scheme, and its cost increases significantly with the increase in the number of reclosing times. Therefore, compared with mechanical DC circuit breakers, the hybrid scheme is more widely used in engineering. However, the current hybrid DC circuit breakers usually use a large number of fully controlled power electronic devices. With the increase in the required breaking current, the devices will further increase, resulting in a significant increase in cost. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of high cost of hybrid DC circuit breakers in the prior art, and thus provide a multi-functional multi-port hybrid DC circuit breaker and a control method therefor.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] In a first aspect, an embodiment of the present invention provides a multi-functional multi-port hybrid DC circuit breaker, including: a power flow control module, a plurality of current-carrying modules, a current-limiting module, a power-consuming module, a breaking module, and a plurality of selection modules. Wherein, one end of the power flow control module is connected to the DC bus wiring port, and the other end is connected to one end of each of the current-carrying modules. The other end of each of the current-carrying modules is connected to each DC line wiring port. The DC bus wiring port and the DC line wiring port are arranged in one-to-one correspondence; one end of each of the selection modules is connected to its corresponding DC line, and the other end is connected to one end of the current-limiting module; the other end of the current-limiting module is respectively connected to one end of the power-consuming module and one end of the breaking module; the other end of the power-consuming module and the other end of the breaking module are connected to the DC bus.

[0007] Optionally, the power flow control module includes: a power electronic switch unit provided corresponding to each DC line, and a capacitor disposed between every two adjacent DC lines, wherein both ends of each capacitor are respectively connected to two adjacent DC lines; the power electronic switch unit includes a power electronic switch device and a pre-charging capacitor.

[0008] Optionally, the current-carrying module includes at least one mechanical switch.

[0009] Optionally, the selection module includes: a mechanical switch and at least one bidirectional power electronic switch unit, wherein the mechanical switch is connected in series with each of the bidirectional power electronic switch units.

[0010] Optionally, the selection module includes: a plurality of series-connected bidirectional power electronic switch units and a non-linear resistor connected in parallel with the plurality of series-connected bidirectional power electronic switch units.

[0011] Optionally, the current-limiting module is a resistive current-limiting module, a capacitive current-limiting module or an inductive current-limiting module.

[0012] Optionally, the energy-consuming module is a lightning arrester.

[0013] Optionally, the opening module includes at least one bidirectional power electronic switch unit.

[0014] In a second aspect, an embodiment of the present invention provides a control method for a multi-functional multi-port hybrid DC circuit breaker, which is applied to the control method for the multi-functional multi-port hybrid DC circuit breaker in the first aspect of the embodiments of the present invention. The control method includes: when receiving a line power flow instruction, locking each power electronic switch unit in the power flow control module to adjust the line power flow.

[0015] Optionally, the control method further includes: when receiving a current DC line fault breaking instruction, locking the power electronic switch unit in the power flow control module of the current DC line and simultaneously turning on the opening module and the selection module connected to the current DC line, so that the fault current of the current DC line flows into the commutation branch; after the current transfer is completed, breaking the current-carrying module in the DC line and the selection module connected to other lines; when the fault current drops within the breaking capacity range of the breaking unit under the action of the current-limiting module, locking the breaking unit and transferring the current to the energy-consuming module for clearing.

[0016] The technical solution of the present invention has the following advantages:

[0017] The multi-functional multi-port hybrid DC circuit breaker provided by the present invention includes: a power flow control module, a plurality of current-carrying modules, a current-limiting module, an energy-consuming module, a breaking module, and a plurality of selection modules. Among them, one end of the power flow control module is connected to the DC bus wiring port, and the other end is connected to one end of each current-carrying module. The other end of each current-carrying module is connected to each DC line wiring port, and the DC bus wiring port and the DC line wiring port are arranged in one-to-one correspondence; one end of each selection module is connected to its corresponding DC line, and the other end is connected to one end of the current-limiting module; the other end of the current-limiting module is respectively connected to one end of the energy-consuming module and one end of the breaking module; the other end of the energy-consuming module and the other end of the breaking module are connected to the DC bus. The above multi-functional multi-port hybrid DC circuit breaker can be applied in a multi-port structure, has the capabilities of power flow control of multiple DC lines, short-circuit current limitation and breaking, reduces the overall volume and cost of the DC circuit breaker, makes it have good technical and economic performance, and can meet the large-scale application requirements of high-voltage DC circuit breakers. Further, by sharing the commutation branch, the equipment investment of the DC circuit breaker is greatly reduced, which is beneficial to the construction of multi-terminal and DC power grids.

[0018] The control method of the multi-functional multi-port hybrid DC circuit breaker provided by the present invention, by configuring the control method of the multi-functional multi-port hybrid DC circuit breaker in a multi-port DC system, can realize the power flow control, short-circuit current limitation and breaking of multiple DC lines simultaneously by using a current-injected DC circuit breaker, reduces the overall volume and cost of the DC circuit breaker, can meet the large-scale application requirements of high-voltage DC circuit breakers, and at the same time greatly reduces the equipment investment of the DC circuit breaker, which is beneficial to the construction of multi-terminal and DC power grids. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a structural diagram of a specific example of the multi-functional multi-port hybrid DC circuit breaker in an embodiment of the present invention;

[0021] Figure 2 It is a topological structural diagram of a specific example of the power flow control module in an embodiment of the present invention;

[0022] Figure 3 It is a topological structural diagram of a specific example of the power electronic switch unit in an embodiment of the present invention;

[0023] Figure 4It is a topological structure diagram of another specific example of the power electronic switch unit in the embodiment of the present invention;

[0024] Figure 5 It is a topological structure diagram of another specific example of the power electronic switch unit in the embodiment of the present invention;

[0025] Figure 6 It is a topological structure diagram of a specific example of the selection module in the embodiment of the present invention;

[0026] Figure 7 It is a topological structure diagram of another specific example of the selection module in the embodiment of the present invention;

[0027] Figure 8 It is a topological structure diagram of another specific example of the selection module in the embodiment of the present invention;

[0028] Figure 9 It is a topological structure diagram of a specific example of the resistive current limiting module in the embodiment of the present invention;

[0029] Figure 10 It is a topological structure diagram of a specific example of the capacitive current limiting module in the embodiment of the present invention;

[0030] Figure 11 It is a topological structure diagram of a specific example of the inductive current limiting module in the embodiment of the present invention;

[0031] Figure 12 It is a structure diagram of another specific example of the multi-functional multi-port hybrid DC circuit breaker in the embodiment of the present invention;

[0032] Figure 13 It is a flowchart of a specific example of the control method of the multi-functional multi-port hybrid DC circuit breaker in the embodiment of the present invention. Detailed implementation manners

[0033] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and can also be the communication inside two elements. It can be a wireless connection or a wired connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0036] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] An embodiment of the present invention provides a multi-functional multi-port hybrid DC circuit breaker, which is applied to multi-terminal and flexible DC power grids. The above-mentioned multi-functional multi-port hybrid DC circuit breaker, as Figure 1 shown, includes: a power flow control module, a plurality of current-carrying modules, a current-limiting module, a power-consuming module, a breaking module, and a plurality of selection modules. Among them, one end of the power flow control module is connected to the DC bus wiring port, and the other end is connected to one end of each current-carrying module. The other end of each current-carrying module is connected to each DC line wiring port. The DC bus wiring port and the DC line wiring port are arranged in one-to-one correspondence; one end of each selection module is connected to its corresponding DC line, and the other end is connected to one end of the current-limiting module; the other end of the current-limiting module is respectively connected to one end of the power-consuming module and one end of the breaking module; the other end of the power-consuming module and the other end of the breaking module are connected to the DC bus.

[0038] In a specific embodiment, the multi-functional multi-port hybrid DC circuit breaker is installed in the DC power grid to realize the conduction of the steady-state current of the DC line during the normal operation of the DC line, and transfer the fault current to the commutation branch after detecting the fault occurring in the DC line to realize the fault blocking function. In the embodiment of the present invention, the DC bus wiring port and the DC line wiring port are not shown in Figure 1 this.

[0039] The multi-functional multi-port hybrid DC circuit breaker provided by the present invention includes: a power flow control module, a plurality of current-carrying modules, a current-limiting module, an energy-consuming module, a breaking module, and a plurality of selection modules. Among them, one end of the power flow control module is connected to the DC bus wiring port, and the other end is connected to one end of each current-carrying module. The other end of each current-carrying module is connected to each DC line wiring port. The DC bus wiring port and the DC line wiring port are arranged in one-to-one correspondence; one end of each selection module is connected to its corresponding DC line, and the other end is connected to one end of the current-limiting module; the other end of the current-limiting module is respectively connected to one end of the energy-consuming module and one end of the breaking module; the other end of the energy-consuming module and the other end of the breaking module are connected to the DC bus. The above multi-functional multi-port hybrid DC circuit breaker can be applied to a multi-port structure, has the capabilities of power flow control of multiple DC lines, short-circuit current limitation and breaking, reduces the overall volume and cost of the DC circuit breaker, enables it to have good technical and economic performance, and can meet the large-scale application requirements of high-voltage DC circuit breakers. Further, by sharing the commutation branch, the equipment investment of the DC circuit breaker is greatly reduced, which is beneficial to the construction of multi-terminal and DC power grids.

[0040] In one embodiment, as Figure 2 shown, the power flow control module includes: a power electronic switch unit arranged in one-to-one correspondence with each DC line, and a capacitor arranged between every two adjacent DC lines. The two ends of each capacitor are respectively connected to two adjacent DC lines; the power electronic switch unit includes a power electronic switch device and a pre-charging capacitor.

[0041] In a specific embodiment, the power flow control module is used to achieve the power flow control of each line under system steady state and the current transfer of the faulty line after system fault. When the power electronic switch unit is blocked, the pre-charging capacitor in the power electronic switch unit is put into operation, a voltage difference is formed between the DC lines to adjust the power flow, and the balance of the capacitor voltages input between adjacent DC lines is realized through the capacitors arranged between every two adjacent DC lines. In the embodiment of the present invention, the power electronic switch unit has various compositions, including the reverse series form of fully controlled devices as Figure 3 shown, in which the pre-charging capacitor with energy storage function is connected in parallel at both ends of the reverse series devices; including the full-bridge module form composed of fully controlled devices as Figure 4 shown, in which the pre-charging capacitor with energy storage function is connected in parallel between the bridge arms; including the full-bridge module form composed of diodes as Figure 5 shown, in which the pre-charging capacitor is connected in parallel between the bridge arms. In the embodiment of the present invention, the power electronic switch devices include: IGBTs, diodes, etc., only taking this as an example, not limited thereto. By configuring the pre-charging capacitor with energy storage function and the pole line capacitor, the power flow transfer between each DC line can be flexibly realized, and the flexibility of the DC power grid can be significantly improved.

[0042] In one embodiment, the current-carrying module includes at least one mechanical switch.

[0043] In a specific embodiment, the current-carrying module is composed of at least one fast mechanical switch, which is mainly used to conduct the rated current during the steady-state operation of the system and withstand the transient voltage during the opening process of the DC circuit breaker after the system fails. By only setting mechanical switches in the current-carrying module, the operating loss is approximately zero, and a water-cooling system is not required, improving the reliability of the circuit breaker.

[0044] In one embodiment, as Figure 6 shown, the selection module includes: a mechanical switch and at least one bidirectional power electronic switch unit, wherein the mechanical switch is connected in series with each bidirectional power electronic switch unit.

[0045] In a specific embodiment, the selection module is a fast switch unit with bidirectional conduction and blocking capabilities, which is mainly used to select and isolate the short-circuit current of the faulty line and the transient opening voltage of the non-faulty line. Optionally, as Figure 7 shown, the selection module may further include: a plurality of series-connected bidirectional power electronic switch units and a non-linear resistor connected in parallel with the plurality of series-connected bidirectional power electronic switch units. Optionally, as Figure 8 shown, the selection module may also be in the form of the reverse parallel connection of a diode valve and a thyristor valve. By configuring a variety of selection module topology designs, the optimal comprehensive performance matching can be achieved according to different DC power grid system network structures and operation requirements, improving the overall technical economy of the equipment.

[0046] In one embodiment, the current-limiting module is a resistive current-limiting module, a capacitive current-limiting module, or an inductive current-limiting module.

[0047] In a specific embodiment, the current-limiting module is mainly used to limit the fault current, and can be a resistive current-limiting module, or a capacitive current-limiting module composed of non-linear capacitors, or an inductive current-limiting module of thyristor-switched reactance. In the embodiment of the present invention, the resistive current-limiting module is as Figure 9 shown, including a variable resistor R1. The capacitive current-limiting module is as Figure 10 shown, including a first resistor R2 and an adjustable capacitor C1, wherein the first resistor R2 is connected in parallel with the adjustable capacitor C1. The inductive current-limiting module is as Figure 11As shown in the figure, it includes a first capacitor C2, a first thyristor T1, a second thyristor T2, a third thyristor T3 and a first inductor L. One end of the first capacitor C2 is connected to the anode of the first thyristor T1, and the other end is connected to the anode of the second thyristor T2 and the cathode of the third thyristor T3. The cathode of the first thyristor T1 is connected to one end of the first inductor L, and the other end of the first inductor L is connected to the cathode of the second thyristor T2 and the anode of the third thyristor T3. By setting the current-limiting module, the short-circuit current can be effectively limited during the current interruption process, reducing the interruption current requirement of the interruption module, which is beneficial to reducing the number of device paralleling. At the same time, it also realizes the sharing of full-controlled devices in multiple lines of the interruption module, significantly reducing the primary cost and volume of the DC circuit breaker from two aspects.

[0048] In one embodiment, the energy-consuming module is a lightning arrester.

[0049] In a specific embodiment, the energy-consuming unit is a series connection of non-linear resistor chips, which is used to absorb the electromagnetic energy of the inductive components in the system and eliminate the short-circuit current.

[0050] In one embodiment, the interruption module includes at least one bidirectional power electronic switch unit.

[0051] In a specific embodiment, the interruption module is a high-speed bidirectional power electronic switch unit for interrupting the short-circuit current. Its typical structure is a reverse series connection of full-controlled devices or a bridge module. In the embodiment of the present invention, the bidirectional power electronic switch unit includes IGBT devices and diodes reversely connected in parallel with the IGBT devices.

[0052] The embodiment of the present invention also provides a control method for a multi-functional multi-port hybrid DC circuit breaker, which is applied to the above-mentioned control method for a multi-functional multi-port hybrid DC circuit breaker. The above control method includes: when receiving a line power flow command, locking the power electronic switch units in the power flow control module to adjust the line power flow.

[0053] In a specific embodiment, the control method specifically takes Figure 12 the current injection type DC circuit breaker shown in the figure as an example for illustration. First, during steady-state operation, the interruption module is in a locked state, and each selection module is in a blocked state. The current flows through the mechanical switch K1, mechanical switch K2, power electronic switch unit 1, and power electronic switch unit 2 on the DC line. When it is necessary to adjust the line power flow, lock the power electronic switch units of two adjacent DC lines, turn on the pre-charging capacitors in the power electronic switch units to change the line power flow, and at the same time, the voltage balance of the capacitors put into the two lines can be achieved through the inter-pole capacitor.

[0054] In one embodiment, as Figure 13 shown in the figure, the control method further includes the following steps:

[0055] Step S1: When receiving the current DC line fault interruption command, lock the power electronic switch unit of the power flow control module in the current DC line, and simultaneously turn on the opening and closing module and the selection module connected to the current DC line, so that the fault current of the current DC line flows into the commutation branch.

[0056] Step S2: After the current transfer is completed, disconnect the current-carrying module in the DC line and the selection module connected to other lines.

[0057] Step S3: When the fault current drops within the opening capacity range of the opening unit under the action of the current limiting module, lock the opening unit and transfer the current to the energy-consuming module for clearing.

[0058] In a specific embodiment, when the circuit breaker detects a fault in DC line 1, lock the power electronic switch unit 1 connected to the faulty DC line 1, and at the same time trigger the IGBT in the opening and closing module to conduct, and turn on the selection module 1, so as to transfer the current on the faulty DC line 1 to the commutation branch. During the current transfer process, the capacitor of the current limiting module shows a high capacitance value to ensure fast commutation. After the commutation is completed, quickly open the mechanical switch K1, and at the same time, the capacitance value of the capacitor in the current limiting module changes with the increase of the voltage. When it reaches a certain voltage threshold, it will quickly drop to a very small capacitance value to quickly establish voltage to limit the short-circuit current. When the fast mechanical switch K1 reaches the withstand transient voltage and the short-circuit current drops to the turn-off level of the opening module, the opening module is locked, and the current is forced to be transferred to the energy-consuming module MOV to achieve current clearing and complete the turn-off. Through the above fault isolation operation, not only can the bus fault be quickly isolated, but also the meshed structure operation of the DC power grid can be maintained, and the utilization rate of each line can be greatly improved.

[0059] When the circuit breaker detects faults in both DC line 1 and DC line 2 simultaneously, synchronously lock the power electronic switch unit 1 connected to the faulty DC line 1 and the power electronic switch unit 2 connected to the faulty DC line 2, and at the same time trigger the IGBT in the opening and closing module to conduct, and synchronously turn on the selection module 1 and the selection module 2, so as to transfer the currents on the faulty DC line 1 and the faulty DC line 2 to the commutation branch. During the current transfer process, the capacitor of the current limiting module shows a high capacitance value to ensure fast commutation. After the commutation is completed, quickly open the mechanical switch K1 in the current-carrying module 1 and the mechanical switch K2 in the current-carrying module 2, and at the same time, the capacitance value of the capacitor in the current limiting module changes with the increase of the voltage. When it reaches a certain voltage threshold, it will quickly drop to a very small capacitance value to quickly establish voltage to limit the short-circuit current. When the fast mechanical switch K1 and the mechanical switch K2 reach the withstand transient voltage and the short-circuit current drops to the turn-off level of the opening module, the opening module is locked, and the current is forced to be transferred to the energy-consuming module MOV to achieve current clearing.

[0060] After a fault occurs in DC line 1, the current rise rate and current amplitude of DC line 1 are monitored in real time. When the current rise rate and current amplitude of DC line 1 return to normal, that is, after the fault of DC line 1 is cleared, first lock the IGBT in the opening and closing module, control the commutation branch connected to the current DC line to stop working, and close the mechanical switch K1 to control the current-carrying module in the DC line to connect to the current DC line. If the fault still exists, then close the IGBT in the opening and closing module again, control the commutation branch connected to the current DC line to start working, so that the fault current of the current DC line flows into the energy-consuming module in the commutation branch to clear the fault current.

[0061] The control method of the multi-functional multi-port hybrid DC circuit breaker provided by the present invention, by configuring the control method of the multi-functional multi-port hybrid DC circuit breaker in a multi-port DC system, can realize the power flow control, short-circuit current limitation and opening of multiple DC lines simultaneously by using the current injection type DC circuit breaker, reduce the overall volume and cost of the DC circuit breaker, meet the requirements of large-scale application of high-voltage DC circuit breakers, and at the same time greatly reduce the equipment investment of the DC circuit breaker, which is beneficial to the construction of multi-terminal and DC power grids.

[0062] Obviously, the above embodiments are only examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A multi-functional multi-port hybrid DC circuit breaker, characterized in that Comprising: A power flow control module, a plurality of current-carrying modules, a current-limiting module, a power-consuming module, a breaking module, and a plurality of selection modules, wherein One end of the power flow control module is connected to the DC bus wiring port, and the other end is connected to one end of each of the current-carrying modules. The other end of each of the current-carrying modules is connected to each DC line wiring port, and the DC bus wiring port and the DC line wiring port are arranged in one-to-one correspondence; One end of each of the selection modules is connected to its corresponding DC line, and the other end is connected to one end of the current-limiting module; the other end of the current-limiting module is respectively connected to one end of the power-consuming module and one end of the breaking module; the other end of the power-consuming module and the other end of the breaking module are connected to the DC bus; The power flow control module includes: a power electronic switch unit arranged in one-to-one correspondence with each DC line, and a capacitor arranged between every two adjacent DC lines, wherein Both ends of each capacitor are respectively connected to two adjacent DC lines; The power electronic switch unit includes a power electronic switch device and a pre-charge capacitor; The selection module includes: a plurality of series-connected bidirectional power electronic switch units and a non-linear resistor connected in parallel with the plurality of series-connected bidirectional power electronic switch units, or a diode valve and a thyristor valve connected in reverse parallel; The current-limiting module is a resistive current-limiting module, a capacitive current-limiting module, or an inductive current-limiting module; The capacitive current-limiting module includes: an adjustable capacitor.

2. The multifunctional multi-port hybrid DC circuit breaker according to claim 1, wherein The current-carrying module includes at least one mechanical switch.

3. The multifunctional multi-port hybrid DC circuit breaker according to claim 1, characterized in that The selection module includes: a mechanical switch and at least one bidirectional power electronic switch unit, wherein the mechanical switch is connected in series with each of the bidirectional power electronic switch units.

4. The multifunctional multi-port hybrid DC circuit breaker according to claim 1, wherein The power-consuming module is a lightning arrester.

5. The multifunctional multi-port hybrid DC circuit breaker according to claim 1, characterized in that, The breaking module includes at least one bidirectional power electronic switch unit.

6. A control method for a multi-functional multi-port hybrid DC circuit breaker, which is applied to the control method for the multi-functional multi-port hybrid DC circuit breaker according to any one of claims 1-5, characterized in that, The control method includes: When receiving a line power flow instruction, locking each power electronic switch unit in the power flow control module to adjust the line power flow.

7. The control method of the multi-functional multi-port hybrid DC circuit breaker according to claim 6, characterized in that, The control method further includes: When receiving a current DC line fault breaking instruction, locking the power electronic switch unit in the power flow control module of the current DC line and simultaneously turning on the breaking module and the selection module connected to the current DC line, so that the fault current of the current DC line flows into the commutation branch; After the current transfer is completed, breaking the current-carrying module in the DC line and the selection module connected to other lines; When the fault current drops within the breaking capacity range of the breaking unit under the action of the current-limiting module, locking the breaking unit and transferring the current to the power-consuming module for clearing.

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