A low-loss integrated power conversion module and method for direct-current distribution network based on high-temperature superconducting tape

Abstract

The application belongs to the cross field of direct current distribution network technology, power electronic power conversion technology and high temperature superconducting application technology. A low-loss integrated power conversion module for direct current distribution network based on high temperature superconducting tape, characterized in that it comprises a power conversion unit, a high-frequency isolation superconducting conversion unit, a cooling integrated unit and a control and protection unit; the power conversion unit adopts a full-bridge semiconductor power topology suitable for direct current distribution network bidirectional power flow; the high-frequency isolation superconducting conversion unit adopts an integrated structure of high-frequency transformer and resonant inductor integrated with high temperature superconducting tape winding; the cooling integrated unit adopts a low-temperature-normal-temperature decoupling design; the control and protection unit is respectively connected with the power conversion unit, the high-frequency isolation superconducting conversion unit and the cooling integrated unit in signal connection. The problems of high loss, low integration, single function and poor engineering adaptability of the existing scheme can be solved.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of DC distribution network technology, power electronic power conversion technology, and high-temperature superconducting application technology, and specifically relates to an integrated power conversion module and method suitable for medium and low voltage DC distribution networks. Background Technology

[0002] With the large-scale integration of distributed new energy sources, energy storage, and DC loads, DC distribution networks, with their advantages of low loss, high controllability, and high power supply reliability, have become one of the core directions for the construction of new power systems. Power conversion modules are the core equipment of DC distribution networks, undertaking the core functions of electrical connection, bidirectional power conversion, electrical isolation, and fault isolation for DC buses of different voltage levels. Their losses, integration, reliability, and fault adaptability directly determine the operating performance and construction cost of the DC distribution network.

[0003] Existing conventional power conversion modules mostly use high-frequency transformers with copper-based windings for electrical isolation. Due to the inherent on-resistance of copper, there are significant winding conduction losses during module operation. At the same time, the skin effect under high-frequency conditions further aggravates the losses, resulting in persistently high overall module losses. Furthermore, conventional modules do not have fault current limiting capabilities. When a short-circuit fault occurs in the DC distribution network, additional protection devices such as DC current limiters and DC circuit breakers need to be connected in series, leading to system redundancy, complex protection logic, and increased construction and maintenance costs. In addition, the connection of additional devices further increases system losses and reduces the operating efficiency of the DC distribution network.

[0004] Existing power conversion solutions based on high-temperature superconducting tapes often simply replace conventional copper windings with high-temperature superconducting tape windings without considering the inherent characteristics of the high-temperature superconducting tapes for coordinated power topology design. This fails to fully leverage the low-loss advantage of superconducting tapes, and the winding structure is not specifically optimized for high-frequency operation, resulting in insufficient AC loss suppression. Furthermore, existing solutions often separate the cooling system of the superconducting components from the power conversion module, leading to low integration and poor thermal and insulation compatibility between low-temperature superconducting components and room-temperature power devices, thus limiting their engineering practicality. In addition, existing solutions are not adapted to the fault characteristics of DC distribution networks and do not utilize the quenching characteristics of superconducting tapes to integrate fault current limiting functions. This fails to address the core pain points of short-circuit fault protection in DC distribution networks and makes it difficult to adapt to the diverse application needs of DC distribution networks. Summary of the Invention

[0005] The purpose of this invention is to provide a low-loss integrated power conversion module and method for DC distribution networks based on high-temperature superconducting tape. By coordinating the design of topology and superconducting tape, integrating multiple functions, and using a high-low temperature decoupled integrated architecture, this invention solves the problems of high loss, low integration, single function, and poor engineering adaptability of existing solutions.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: a low-loss integrated power conversion module for DC distribution networks based on high-temperature superconducting tape, characterized in that it includes a power conversion unit, a high-frequency isolated superconducting conversion unit, a cooling integrated unit, and a control and protection unit; The power conversion unit adopts a full-bridge semiconductor power topology adapted to bidirectional power flow in DC distribution networks. Its main circuit integrates power semiconductor devices to realize bidirectional conversion and regulation of DC power. The high-frequency isolated superconducting converter unit adopts an integrated structure of a high-frequency transformer and a resonant inductor wound with high-temperature superconducting tape. It has a superconducting component with high-temperature superconducting tape as the core. Its primary and secondary sides are electrically connected to the primary and secondary circuits of the power conversion unit, respectively, to achieve electrical isolation and voltage matching between the primary and secondary sides. It also uses its own resonant characteristics to cooperate with the power conversion unit to achieve soft switching operation across the entire load range. The cooling integration unit adopts a low-temperature-room-temperature decoupled design, which respectively connects the low-temperature cooling cavity of the high-frequency isolation superconducting converter unit, the room-temperature heat dissipation channel of the power conversion unit, and the heat dissipation channel of the control and protection unit. It is used to provide a suitable working environment for the superconducting components of the high-frequency isolation superconducting converter unit, the power semiconductor devices of the power conversion unit, and the core devices of the control and protection unit. The control and protection unit is connected to the power conversion unit, the high-frequency isolation superconducting conversion unit, and the cooling integration unit, respectively, and is used to realize the soft switching closed-loop control of the module, superconducting quench state monitoring, short-circuit fault current limiting collaborative protection, and multi-module parallel networking control.

[0007] Furthermore, the power conversion unit can adopt any one of the following topologies: bidirectional dual active bridge topology, LLC resonant topology, or three-level bidirectional DC-DC topology, adapting to DC distribution network application scenarios with different voltage and power levels. Furthermore, the power semiconductor devices of the power conversion unit adopt silicon carbide-based or gallium nitride-based wide bandgap semiconductor devices, adapting to high-frequency switching conditions and reducing switching losses. Furthermore, the main circuit of the power conversion unit adopts a stacked busbar integrated structure for electrical connection, reducing stray inductance in the main circuit and minimizing electromagnetic interference.

[0008] Furthermore, the high-frequency isolated superconducting converter unit includes a magnetic core, a primary winding, a secondary winding, and a resonant inductor. The primary winding, secondary winding, and resonant inductor are all integrally wound using high-temperature superconducting tape, achieving structural integration and reducing connection losses. Furthermore, the primary and secondary windings employ a multi-strand parallel transposed disc winding structure to suppress AC losses under high-frequency operating conditions and fully utilize the low-loss advantage of the superconducting tape.

[0009] Furthermore, the high-temperature superconducting tape is a second-generation REBCO high-temperature superconducting tape or a Bi-based high-temperature superconducting tape, which is suitable for low-temperature working environments and power transmission requirements.

[0010] Furthermore, the cooling integration unit includes independent cryogenic cooling circuits and ambient temperature heat dissipation circuits. The cryogenic cooling circuit is sealed and connected to the cryogenic cooling chamber of the high-frequency isolated superconducting converter unit. The ambient temperature heat dissipation circuit is connected to the heat dissipation components of the power conversion unit and the control and protection unit, respectively, to achieve decoupled control between cryogenic and ambient temperature operating conditions and avoid waste of cooling capacity. Furthermore, the cryogenic cooling circuit can adopt any one of a closed-loop liquid nitrogen cycle refrigeration structure, a GM refrigerator structure, or a pulse tube refrigeration structure to adapt to different cryogenic operating temperature range requirements. Furthermore, a vacuum insulation sealing structure is provided between the cryogenic cooling chamber and the ambient temperature chamber to reduce cooling capacity leakage and lower the load on the refrigeration system.

[0011] Furthermore, the high-frequency isolated superconducting converter unit is electrically connected to the power conversion unit through a low-temperature insulating sleeve, which is installed inside a vacuum heat-insulating encapsulation structure to balance insulation and sealing performance.

[0012] Furthermore, the control and protection unit adopts a DSP+FPGA dual-core controller architecture, balancing the computational power of the control algorithm with the response speed of the protection logic. Furthermore, the control and protection unit integrates a soft-switching closed-loop control module, a superconducting quench fault detection module, a short-circuit current limiting collaborative protection module, and a multi-module parallel current sharing control module, achieving stable operation under all working conditions and functional adaptability across all scenarios.

[0013] Furthermore, the power conversion unit, high-frequency isolated superconducting conversion unit, cooling integration unit, and control and protection unit are integrated into a single module cabinet, achieving a high degree of integration of the whole machine, reducing the installation volume, and improving engineering adaptability.

[0014] This invention also provides a high-frequency isolated superconducting converter unit for the aforementioned power conversion module, comprising a magnetic core, a primary winding, a secondary winding, and a resonant inductor; the primary winding, secondary winding, and resonant inductor are all integrally wound using high-temperature superconducting tape, constituting the superconducting component of the module; the primary and secondary windings adopt a multi-strand parallel transposed winding structure, and the primary winding, secondary winding, resonant inductor, and magnetic core are integrally encapsulated within a cryogenic cooling cavity; the primary and secondary windings of the high-frequency isolated superconducting converter unit are respectively connected to the primary winding of the power conversion unit. The secondary circuit is electrically connected, and its cryogenic cooling chamber is sealed and connected to the cryogenic cooling circuit of the cooling integrated unit. Its built-in status monitoring component is signal-connected to the control and protection unit. The high-frequency isolation superconducting converter unit is used to realize the electrical isolation and voltage level matching of the primary and secondary circuits of the module. It forms a resonant characteristic through its own integrated resonant inductor, and works with the power conversion unit to realize soft switching operation in the full load range. At the same time, under the short-circuit fault condition of DC distribution network, it can realize short-circuit fault current limiting through the transient rise of resistance after the high-temperature superconducting tape loses its quench.

[0015] Furthermore, the primary and secondary windings of the high-frequency isolated superconducting converter unit adopt a disc-shaped winding structure, with an insulating layer between the winding layers to prevent short-circuit faults between the windings. Furthermore, the magnetic core uses a nanocrystalline or ferrite core, suitable for high-frequency operating conditions and reducing core loss. Furthermore, the winding leads employ a low-resistance superconducting connector structure to reduce connection losses at the connectors.

[0016] The present invention also provides a DC distribution network power conversion and fault protection method based on the above-mentioned power conversion module, characterized by the following steps: S1. Bidirectional power conversion control steps: Based on the power flow requirements of the DC distribution network, the switching sequence of the power conversion unit is adjusted by the control and protection unit to realize the bidirectional power conversion of the module, and the soft switching operation of the full load range is realized through the resonant characteristics of the high-frequency isolation superconducting conversion unit. S2. Status monitoring steps: Real-time acquisition of the module's operating parameters and the superconducting tape's status parameters to determine the superconducting tape's operating status; S3. Fault Current Limiting Protection Steps: When a short-circuit fault is detected in the DC distribution network and the superconducting tape shows a tendency to lose quench, the control and protection unit triggers the collaborative protection logic. Combined with the inherent characteristics of the transient rise in resistance after the superconducting tape loses quench, the short-circuit current is quickly suppressed and the fault is isolated. S4. Parallel Networking Control Steps: When multiple modules are connected in parallel, current sharing control between multiple modules is achieved through the control and protection unit, adapting to the distributed access requirements of DC distribution networks in multiple scenarios.

[0017] Furthermore, in step S1, soft-switching operation is achieved using any one of phase-shift control, frequency conversion control, or pulse width modulation control, depending on the topology of the power conversion unit. Furthermore, in step S3, the collaborative protection logic includes switching transistor blocking timing, cooling system emergency adjustment timing, and fault signal uploading timing, achieving end-to-end collaborative fault response. Furthermore, in step S4, multi-module current sharing control adopts master-slave control or droop control methods to adapt to different networking scenarios.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention integrates high-temperature superconducting tape into the high-frequency isolation transformer winding and resonant inductor through the synergistic design of power conversion topology and the characteristics of high-temperature superconducting tape, forming an integrated superconducting conversion structure. This fully utilizes the low conduction loss characteristics of high-temperature superconducting tape, while achieving soft-switching operation across the entire load range through the inherent characteristics of the topology. This reduces the conduction loss and switching loss of the module from the design source, resulting in a significant reduction in the overall loss of the module.

[0019] 2. This invention utilizes the inherent physical characteristic of the transient resistance surge after quenching of high-temperature superconducting tape to embed fault current limiting functionality into the module's design. This eliminates the need for additional DC current limiters and protection devices, simplifying the protection architecture of the DC distribution network system and reducing system construction and maintenance costs. Furthermore, through collaborative protection logic matched to the quenching characteristics of the superconducting tape, it achieves rapid suppression of short-circuit current while avoiding performance degradation caused by long-term overcurrent in the superconducting tape. This significantly improves the fault response capability and operational reliability of the module and the DC distribution network. It fully leverages the technical advantages of high-temperature superconducting tape and adapts to the core application requirements of DC distribution networks.

[0020] 3. This invention adopts a low-temperature-room-temperature decoupled cooling integration design, which sets up independent cooling and heat dissipation circuits for superconducting components and room-temperature power devices respectively. At the same time, the high and low temperature cavities are isolated through a vacuum thermal insulation encapsulation structure, which structurally solves the risks of cold leakage and insulation breakdown. It achieves a high degree of integration between superconducting components and power conversion units, greatly improves the integration of modules, reduces the overall installation volume, and enhances engineering practicality and scenario adaptability.

[0021] 4. This invention adopts an integrated end-to-end packaging design, which reduces stray inductance in the main circuit and reduces electromagnetic interference through a stacked bus structure. At the same time, it is equipped with a multi-module parallel current sharing control strategy, which can adapt to the distributed access requirements of various scenarios such as DC distribution network converter stations, distribution areas, and distributed source-grid-load-storage, and has strong engineering promotion value. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is an overall structural block diagram of a low-loss integrated power conversion module for DC distribution networks based on high-temperature superconducting tape according to the present invention.

[0024] Figure 2 This is a schematic diagram of an optional topology for the power conversion unit described in this invention.

[0025] Figure 3 This is a simplified structural diagram of the high-frequency isolated superconducting converter unit described in this invention.

[0026] Figure 4 This is a schematic diagram of the circuit connection of the cooling integrated unit described in this invention.

[0027] Figure 5 This is a schematic diagram of the integrated layout of the module described in this invention.

[0028] Figure 6 This is a flowchart of the DC power conversion and fault protection method for distribution networks described in this invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0030] This specific embodiment provides a low-loss integrated power conversion module for DC distribution networks based on high-temperature superconducting tape, which is suitable for application scenarios of medium and low voltage DC distribution networks. The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0031] like Figure 1 As shown in the figure, the low-loss integrated power conversion module for DC distribution network based on high-temperature superconducting tape described in this embodiment includes four core components: a power conversion unit, a high-frequency isolation superconducting conversion unit, a cooling integrated unit, and a control and protection unit. The four units are connected by electrical and signal connections to form a complete module.

[0032] The power conversion unit adopts a full-bridge semiconductor power topology adapted to bidirectional power flow in DC distribution networks. In this embodiment, the power conversion unit adopts a bidirectional dual active bridge topology, the schematic diagram of which is shown below. Figure 2 As shown, it includes a primary-side full-bridge circuit and a secondary-side full-bridge circuit, which are respectively connected to the primary-side winding and the secondary-side winding of the high-frequency isolation superconducting converter unit; the power semiconductor devices of the power conversion unit adopt silicon carbide-based wide bandgap semiconductor devices, which are suitable for high-frequency switching conditions; the main circuit of the power conversion unit adopts a stacked bus integrated structure to realize the electrical connection between each power device, reduce the stray inductance of the main circuit, and reduce electromagnetic interference.

[0033] like Figure 3 As shown, the high-frequency isolated superconducting converter unit described in this embodiment comprises four main functional components: a magnetic core, a primary winding, a secondary winding, and a resonant inductor. The primary winding, secondary winding, and resonant inductor are all integrally wound using second-generation REBCO high-temperature superconducting tape, forming the superconducting components of the module, achieving structural integration and reducing connection losses. The primary and secondary windings employ a multi-strand parallel transposed disc winding structure, with insulating layers between winding layers to suppress AC losses under high-frequency operating conditions. The magnetic core uses a nanocrystalline core, suitable for high-frequency operating conditions, reducing core losses. The winding leads employ a low-resistance superconducting connector structure to reduce connection losses at the connectors. All the above components are encapsulated within a cryogenic cooling cavity, forming a sealed cryogenic operating environment to ensure the stable operation of the superconducting tape.

[0034] like Figure 4 As shown, the cooling integrated unit described in this embodiment adopts a low-temperature-room-temperature decoupled design, with its core consisting of two independent branches: a low-temperature cooling circuit and a room-temperature heat dissipation circuit. The low-temperature cooling circuit uses a closed-loop liquid nitrogen circulation refrigeration structure and is sealed and connected to the low-temperature cooling cavity of the high-frequency isolation superconducting converter unit, providing a stable low-temperature operating environment for the superconducting winding. The room-temperature heat dissipation circuit is connected to the heat sink of the power conversion unit and the heat dissipation components of the control and protection unit, respectively, to provide heat dissipation for the power semiconductor devices. A vacuum thermal insulation encapsulation structure is set between the low-temperature cooling cavity and the room-temperature cavity to reduce cold leakage and lower the load on the refrigeration system. The high-frequency isolation superconducting converter unit achieves electrical connection with the power conversion unit through a low-temperature insulating sleeve, which is inserted inside the vacuum thermal insulation encapsulation structure, taking into account both insulation and sealing performance.

[0035] The control and protection unit adopts a DSP+FPGA dual-core controller architecture, which is connected to the drive circuit of the power conversion unit, the status monitoring component of the high-frequency isolated superconducting converter, and the control module of the cooling integration unit. The control and protection unit has built-in soft switching closed-loop control module, superconducting quench fault detection module, short-circuit current limiting collaborative protection module and multi-module parallel current sharing control module, which respectively realize the corresponding control and protection functions.

[0036] like Figure 5 As shown, in this embodiment, the power conversion unit, high-frequency isolation superconducting conversion unit, cooling integration unit, and control and protection unit are integrated into a single module cabinet according to electrical connection logic and functional adaptability, thereby achieving high integration of the whole machine, reducing installation volume, and improving engineering adaptability.

[0037] The working principle of the module described in this embodiment is as follows: Under normal operating conditions, the control and protection unit adjusts the switching timing of the power conversion unit according to the power flow requirements of the DC distribution network. Phase-shift control enables bidirectional power conversion of the module. Simultaneously, the resonant characteristics of the high-frequency isolated superconducting converter unit, in conjunction with the power conversion unit, achieve soft-switching operation across the entire load range, significantly reducing switching losses. The high-temperature superconducting strip windings exhibit extremely low on-resistance under low-temperature conditions, significantly reducing winding conduction losses and achieving low-loss operation of the entire module. The low-temperature cooling circuit and the ambient-temperature heat dissipation circuit of the cooling integration unit operate independently, providing suitable working environments for the superconducting components, power devices, and control core devices, ensuring stable module operation.

[0038] Under fault conditions, when a short-circuit fault occurs in the DC distribution network, the loop current rises rapidly. The control and protection unit, through signal connection with the high-frequency isolation superconducting converter unit, collects the status parameters of the superconducting tape in real time. When a loss of quench trend is detected in the superconducting tape, the collaborative protection logic is immediately triggered. At the same time, the superconducting tape loses quench under overcurrent conditions, and the resistance transiently increases, limiting the rapid rise of the short-circuit current. Combined with the switching transistor lockout and fault signal uploading protection actions of the control and protection unit, the short-circuit current is quickly suppressed and the fault is isolated. No additional current limiting device is required, which greatly improves the fault response capability of the DC distribution network.

[0039] This embodiment also provides a DC distribution network power conversion and fault protection method based on the above modules, the flowchart of which is shown below. Figure 6 As shown, it includes the following steps: S1. Bidirectional power conversion control steps: Based on the power flow requirements of the DC distribution network, the switching sequence of the power conversion unit is adjusted by the control and protection unit. The phase-shift control method is used to realize the bidirectional power conversion of the module, and the soft-switching operation of the full load range is realized through the resonant characteristics of the high-frequency isolation superconducting conversion unit. S2. Status monitoring steps: Real-time acquisition of the module's operating voltage and current parameters, as well as the temperature and voltage parameters of the superconducting tape, to determine the operating status of the superconducting tape in real time; S3. Fault Current Limiting Protection Steps: When a short-circuit fault is detected in the DC distribution network and the superconducting tape shows a tendency to lose quench, the control and protection unit triggers the collaborative protection logic, including the switching transistor blocking sequence, the cooling system emergency adjustment sequence, and the fault signal uploading sequence. Combined with the inherent characteristics of the transient rise in resistance after the superconducting tape loses quench, the short-circuit current is quickly suppressed and the fault is isolated. S4. Parallel Networking Control Steps: When multiple modules are connected in parallel, the control and protection unit adopts a master-slave control method to achieve current sharing control among multiple modules, adapting to the distributed access requirements of DC distribution networks in multiple scenarios.

[0040] It should be noted that the power conversion topology, cooling method, and control method described in this invention are not limited to those listed in this embodiment. The appropriate topology, cooling method, and control method can be selected according to the needs of the actual application scenario, and all of them are within the protection scope of this invention.

Claims

1. A low-loss integrated power conversion module for DC distribution networks based on high-temperature superconducting tape, characterized in that... It includes a power conversion unit, a high-frequency isolated superconducting conversion unit, a cooling integrated unit, and a control and protection unit; The power conversion unit adopts a full-bridge semiconductor power topology adapted to bidirectional power flow in DC distribution networks. Its main circuit integrates power semiconductor devices to realize bidirectional conversion and regulation of DC power. The high-frequency isolated superconducting converter unit adopts an integrated structure of a high-frequency transformer and a resonant inductor wound with high-temperature superconducting tape. It has a superconducting component with high-temperature superconducting tape as the core. Its primary and secondary sides are electrically connected to the primary and secondary circuits of the power conversion unit, respectively, to achieve electrical isolation and voltage matching between the primary and secondary sides. It also uses its own resonant characteristics to cooperate with the power conversion unit to achieve soft switching operation across the entire load range. The cooling integration unit adopts a low-temperature-room-temperature decoupled design, which respectively connects the low-temperature cooling cavity of the high-frequency isolation superconducting converter unit, the room-temperature heat dissipation channel of the power conversion unit, and the heat dissipation channel of the control and protection unit. It is used to provide a suitable working environment for the superconducting components of the high-frequency isolation superconducting converter unit, the power semiconductor devices of the power conversion unit, and the core devices of the control and protection unit. The control and protection unit is connected to the power conversion unit, the high-frequency isolation superconducting conversion unit, and the cooling integration unit, respectively, and is used to realize the soft switching closed-loop control of the module, superconducting quench state monitoring, short-circuit fault current limiting collaborative protection, and multi-module parallel networking control.

2. The low-loss integrated power conversion module for DC distribution networks based on high-temperature superconducting tape according to claim 1, characterized in that, The power conversion unit adopts any one of the following topologies: bidirectional dual active bridge topology, LLC resonant topology, or three-level bidirectional DC-DC topology. The power semiconductor devices of the power conversion unit adopt silicon carbide-based or gallium nitride-based wide bandgap semiconductor devices. The main circuit of the power conversion unit adopts a stacked bus integrated structure to achieve electrical connection.

3. The low-loss integrated power conversion module for DC distribution networks based on high-temperature superconducting tape according to claim 1, characterized in that, The high-frequency isolated superconducting converter unit includes a magnetic core, a primary winding, a secondary winding, and a resonant inductor. The primary winding, secondary winding, and resonant inductor are all integrally wound using high-temperature superconducting tape. The primary winding and secondary winding adopt a multi-strand parallel transposed disc winding structure.

4. A low-loss integrated power conversion module for DC distribution networks based on high-temperature superconducting tape according to claim 1, characterized in that, The cooling integration unit includes an independent low-temperature cooling circuit and a normal-temperature heat dissipation circuit. The low-temperature cooling circuit is sealed and connected to the low-temperature cooling cavity of the high-frequency isolated superconducting converter unit. The normal-temperature heat dissipation circuit is connected to the heat dissipation components of the power conversion unit and the control and protection unit respectively, realizing decoupled control between low-temperature and normal-temperature operating conditions. The low-temperature cooling circuit adopts any one of the following: closed-loop liquid nitrogen cycle refrigeration structure, GM refrigerator structure, or pulse tube refrigeration structure. A vacuum heat insulation encapsulation structure is set between the low-temperature cooling cavity and the normal-temperature cavity.

5. A low-loss integrated power conversion module for DC distribution networks based on high-temperature superconducting tape according to claim 1, characterized in that, The high-frequency isolated superconducting converter unit is electrically connected to the power conversion unit through a low-temperature insulating sleeve, which is installed inside a vacuum-insulated encapsulation structure.

6. A low-loss integrated power conversion module for DC distribution networks based on high-temperature superconducting tape according to claim 1, characterized in that, The control and protection unit adopts a DSP+FPGA dual-core controller architecture. The control and protection unit has a built-in soft switching closed-loop control module, a superconducting quench fault detection module, a short-circuit current limiting collaborative protection module, and a multi-module parallel current sharing control module.

7. A low-loss integrated power conversion module for DC distribution networks based on high-temperature superconducting tape according to claim 1, characterized in that, The power conversion unit, high-frequency isolated superconducting conversion unit, cooling integration unit, and control and protection unit are integrated inside a single module cabinet.

8. A low-loss integrated power conversion module for DC distribution networks based on high-temperature superconducting tape according to claim 1, characterized in that... It also includes a high-frequency isolated superconducting converter unit, which comprises a magnetic core, a primary winding, a secondary winding, and a resonant inductor. The primary winding, secondary winding, and resonant inductor are all integrally wound using high-temperature superconducting tape, forming the superconducting components of the module. The primary and secondary windings adopt a multi-strand parallel transposed winding structure. The primary winding, secondary winding, resonant inductor, and magnetic core are integrally encapsulated within a cryogenic cooling cavity. The primary and secondary windings of the high-frequency isolated superconducting converter unit are electrically connected to the primary and secondary circuits of the power conversion unit, respectively. Its cryogenic cooling cavity is sealed and connected to the cryogenic cooling circuit of the cooling integration unit. Its built-in status monitoring components are signal-connected to the control and protection unit.

9. A low-loss integrated power conversion module for DC distribution networks based on high-temperature superconducting tape according to claim 1, characterized in that... The primary and secondary windings of the high-frequency isolated superconducting converter unit adopt a pancake winding structure, and an insulating isolation layer is set between the winding layers to avoid short circuit faults between the windings. The magnetic core adopts a nanocrystalline magnetic core or a ferrite magnetic core, and the lead-out end of the winding adopts a low-resistance superconducting connector structure.

10. A method for DC distribution network power conversion and fault protection based on a low-loss integrated power conversion module for DC distribution networks based on high-temperature superconducting tape as described in claim 1, characterized in that... Includes the following steps: S1. Bidirectional power conversion control steps: Based on the power flow requirements of the DC distribution network, the switching sequence of the power conversion unit is adjusted by the control and protection unit to realize the bidirectional power conversion of the module, and the soft switching operation of the full load range is realized through the resonant characteristics of the high-frequency isolation superconducting conversion unit. S2. Status monitoring steps: Real-time acquisition of the module's operating parameters and the superconducting tape's status parameters to determine the superconducting tape's operating status; S3. Fault Current Limiting Protection Steps: When a short-circuit fault is detected in the DC distribution network and the superconducting tape shows a tendency to lose quench, the control and protection unit triggers the collaborative protection logic. Combined with the inherent characteristics of the transient rise in resistance after the superconducting tape loses quench, the short-circuit current is quickly suppressed and the fault is isolated. S4. Parallel Networking Control Steps: When multiple modules are connected in parallel, current sharing control between multiple modules is achieved through the control and protection unit, adapting to the distributed access requirements of DC distribution networks in multiple scenarios.

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