A multi-magnet sharing power supply system and a cross-branch switching method for a fusion device

Abstract

This invention discloses a multi-magnet shared power supply system and cross-branch switching method for fusion devices, belonging to the field of high-power power electronics and fusion device magnet power supply technology. It addresses the problem of simultaneously ensuring magnet current continuity and electrical safety during shared module switching when multiple magnet branches are configured with high-power converters at peak values. The system includes a common medium-voltage DC bus, a shared pulse power module pool, series-parallel reconfigurable connection units, a branch selection matrix, multiple magnet branches, and a coordination controller. Each magnet branch is equipped with a continuously connected branch holding power supply. Shared modules are configured into one or more electrically independent shared module groups as needed and selectively connected to the target branch, connected in series with the branch holding power supply. During cross-branch switching, branch holding and freewheeling, module current reduction, original branch isolation, target end pre-charging and voltage matching, state verification, and soft start are executed sequentially to achieve high-power module cross-branch reuse while maintaining magnet current continuity.

Description

Technical Field

[0001] This invention relates to the field of high-power power electronics and fusion device magnet power supply technology, and particularly to a multi-magnet shared power supply system for fusion devices and a cross-branch switching method. Background Technology

[0002] Magnetic confinement fusion devices typically employ multiple magnet branches, such as a central solenoid coil, a poloidal field coil, and a vertical stabilization coil. During a single discharge, different magnet branches undergo operational phases including pre-excitation, current boost, configuration establishment, peak maintenance, descent, and demagnetization. The magnet power supply therefore needs to continuously carry a large magnet current and provide rapidly changing forward or reverse voltages depending on the operational phase, while also handling the feedback energy released by the magnets.

[0003] Existing multi-magnet power supply systems typically configure converter equipment separately according to the maximum voltage, maximum current, and peak power of each magnet branch. However, the maximum power demands of different magnet branches do not necessarily occur simultaneously. Even with independent configuration, the high-power converter equipment for each branch still needs to be configured according to its own peak demand. Consequently, some equipment operates at low load or in standby mode for extended periods, leaving room for further optimization in terms of the total installed capacity and equipment utilization on the magnet side.

[0004] Existing technologies also include schemes that use a common DC bus for power coordination across multiple branches. For example, Chinese invention patent CN108539777A (application number 201810443571.0, publication date September 14, 2018) discloses a power control method for low-voltage flexible distribution network power supply systems. In this system, multiple AC buses can be connected to a common DC bus via flexible DC converters, and energy storage and photovoltaic devices can be connected to the common DC bus. Power transfer between different AC lines can be achieved through the flexible DC converters, and the energy storage devices can also provide emergency power support. While this approach enables energy coordination between different lines, each flexible DC converter is typically fixedly connected to its corresponding AC bus, and its power conversion capacity is not used as a common power module that can be redistributed among different load branches.

[0005] To address the need for multiple DC units to connect to a medium-voltage DC bus, Chinese invention patent application CN116388142A (application number 202310373104.6, publication date July 4, 2023) discloses a power electronic transformer suitable for medium-voltage DC grid-connected interfaces of multiple DC units. The output sides of multiple sub-modules can be connected in series to the medium-voltage DC bus. Each sub-module is connected to a low-voltage DC bus, a photovoltaic array, an energy storage device, or a DC load, respectively. The differential power between different sub-modules is adjusted through a resonant power branch and a coupling transformer. This type of technology mainly solves the problem of output voltage balancing and power transfer among multiple fixed sub-modules, with each sub-module still corresponding to a specific DC unit.

[0006] For magnet power supply in fusion devices, the magnet coils have significant inductance, and the magnet current cannot change arbitrarily during power supply module switching. If only a common high-power converter is installed and connected sequentially to different magnet branches via ordinary switches, the current continuity of the original magnet branch, voltage stress during switch opening and closing, port voltage difference and inrush current when the target branch is connected, and abnormal current paths that may form between different branches need to be addressed during cross-branch switching. Furthermore, the voltage levels, instantaneous power, and high-dynamic operating periods required by different magnet branches are not entirely the same. Simply establishing a common DC bus or adopting a fixed modular converter structure cannot directly achieve safe dynamic reuse of high-power converter capacity among multiple magnet branches.

[0007] Therefore, the technical problem to be solved is: under the condition of ensuring the continuity of current in multiple fusion magnet branches and meeting the dynamic voltage requirements of different operating stages, high-power converter resources can be reconfigured into one or more electrically independent shared module groups according to actual needs, safely distributed and switched across multiple magnet branches, and avoid current interruption, inrush current and switching overvoltage during the switching process of large inductive magnet loads. Summary of the Invention

[0008] The technical problem to be solved by this invention is to realize the reconfiguration of high-power converter resources according to actual needs, safe allocation among multiple magnet branches, and cross-branch switching, while ensuring the continuity of current in multiple fusion magnet branches and meeting the dynamic voltage requirements of different operating stages. This reduces the installation capacity redundancy caused by configuring high-power converter equipment for each magnet branch according to peak demand, and reduces the risks of current interruption, inrush current, and switching overvoltage during the switching process.

[0009] To achieve the above objectives, this invention proposes a multi-magnet shared power supply system for a fusion device, comprising a common medium-voltage DC bus, a shared pulse power module pool, a series-parallel reconfigurable connection unit, a branch selection matrix, multiple magnet branches, and a coordination controller. Each magnet branch includes a branch holding power supply and a magnet coil. The branch holding power supply is continuously connected to the corresponding magnet branch during magnet operation to provide the holding voltage and current path required to maintain the continuity of the magnet current. The shared pulse power module pool includes multiple bidirectional DC / DC power modules. The input side of each power module is connected to the common medium-voltage DC bus, and the output side is connected to the series-parallel reconfigurable connection unit. The series-parallel reconfigurable connection unit combines the multiple bidirectional DC / DC power modules into one or more electrically independent shared power supply systems based on the voltage, current, or power requirements of one or more target magnet branches. The module group, each with an independent output terminal, is selectively connected to the corresponding target magnet branch via the branch selection matrix. When the shared module group is connected to the target magnet branch, it forms a series voltage superposition relationship with the corresponding branch power supply and jointly supplies power to the magnet coil. The branch power supply bears the holding voltage component required for the continuous maintenance of the magnet current, while the shared module group bears the pulse voltage or pulse power component required for the magnet current boosting, rapid configuration control, rapid current reduction, or demagnetization stages. The coordination controller determines the composition of the shared module group and the target magnet branch according to the operating stage and pulse requirements of each magnet branch. During the period when the shared module group exits the original magnet branch or switches to another target magnet branch, it controls the original magnet branch to establish a continuous current path, so that the shared pulse power module can be time-division multiplexed among multiple magnet branches, and different shared module groups can be connected to different magnet branches simultaneously.

[0010] Preferably, the rated current of the branch holding power supply is determined according to the maximum continuous current of the corresponding magnet coil, and the rated voltage of the branch holding power supply is used to cover the magnet coil resistance voltage drop, line voltage drop, the adjustment voltage required for magnet flat-top maintenance or the independent maintenance of magnet current by the branch holding power supply, and the holding voltage during the switching of the shared pulse power module.

[0011] Preferably, each of the bidirectional DC / DC power modules has an output terminal that is electrically isolated from each other and can be floated; the series-parallel reconfigurable connection unit connects multiple power modules in series to form a module chain to improve the output voltage of the shared module group, and connects one or more module chains that meet the voltage requirements in parallel to improve the output current or power capability of the shared module group; any shared pulse power module belongs to only one shared module group during the same scheduling period.

[0012] Preferably, the branch selection matrix is ​​provided with module group input terminals corresponding to the independent output terminals of each shared module group and branch interfaces corresponding to each magnet branch, and includes a main connection switch, a bidirectional blocking switch, a freewheeling channel, a precharge and voltage matching channel, and a hardware interlocking unit; the hardware interlocking unit restricts the same shared module group from forming a direct electrical connection with two magnet branches at the same time, while allowing different shared module groups to connect to different magnet branches respectively.

[0013] Preferably, when the shared module group is switched from the original magnet branch to the target magnet branch, the coordination controller performs the following actions in sequence: maintaining the power supply of the original magnet branch in a sustained state and establishing a freewheeling path; controlling the shared module group to be switched to reduce voltage and current; disconnecting the main connection switch corresponding to the original magnet branch and confirming electrical isolation after the output current of the shared module group is lower than the switching threshold; performing pre-charging and voltage matching on the interface of the target magnet branch; closing the main connection switch of the target magnet branch after the output polarity, port voltage difference, insulation status, and hardware interlock meet the access conditions; and controlling the shared module group to perform current-limited soft start and restore the target pulse power.

[0014] Preferably, the switching threshold is determined based on the allowable breaking current of the main connection switch, the parasitic inductance of the switching circuit, and the allowable overvoltage; the pre-charging and voltage matching are achieved through at least one of current-limiting resistor pre-charging, controlled bidirectional converter pre-charging, or active voltage tracking; after the target magnet branch is connected, the coordination controller controls the soft start of the shared module group according to the allowable output voltage change rate and output current change rate of the target magnet branch.

[0015] Preferably, the coordination controller collects the current and voltage of each magnet branch, the voltage of the common medium-voltage DC bus, the temperature and insulation status of each shared pulse power module, and the switching status of the branch selection matrix; when one or more magnet branches have pulse power requirements, the module composition and target magnet branch of each shared module group are determined according to the voltage requirements, power requirements, operating priorities, requirement duration, module switching time, magnet current change rate, and spare module capacity of each magnet branch.

[0016] Preferably, the allocation of the shared pulse power modules satisfies the following: the same shared pulse power module is allocated to at most one shared module group during the same scheduling period; the total series voltage of each shared module group covers the pulse voltage requirement of the corresponding target magnet branch, and the total allowable current or total power of each parallel module chain covers the current or power requirement of the corresponding target magnet branch; different shared module groups maintain electrical independence on the output side; the coordination controller also determines the shareable pulse power modules based on the temperature and cumulative conduction time of each shared pulse power module, the switching dead zone of the shared module group, and the number of spare modules.

[0017] Preferably, it further includes a grid interface unit and a hybrid energy storage unit; the grid interface unit includes a main transformer and a bidirectional AC / DC converter, the AC side of the bidirectional AC / DC converter is connected to the AC grid via the main transformer, and the DC side is connected to the common medium-voltage DC bus; the hybrid energy storage unit includes a battery energy storage device, a supercapacitor energy storage device, and a bidirectional energy storage converter, the battery energy storage device and the supercapacitor energy storage device are connected to the common medium-voltage DC bus via the bidirectional energy storage converter.

[0018] Preferably, the battery energy storage device is used to handle the first power component, and the supercapacitor energy storage device is used to handle the second power component, the fast pulse power, and the transient power during the switching process of the shared pulse power module, wherein the change frequency of the first power component is lower than the change frequency of the second power component.

[0019] Preferably, the coordination controller sets amplitude and rate of change limits for the grid-side power of the bidirectional AC / DC converter, allocates the first power component of the power difference exceeding the grid-side capacity to the battery energy storage device, and allocates the second power component to the supercapacitor energy storage device; when the magnet branch releases energy, the released energy is preferentially supplied to other magnet branches that are simultaneously drawing power, and secondly used to charge the hybrid energy storage unit. When the absorption capacity of the hybrid energy storage unit is insufficient, the energy is fed back to the AC grid through the bidirectional AC / DC converter.

[0020] Preferably, the capacity of the shared pulse power module pool is determined according to the simultaneous pulse power requirements of each magnet branch. Without considering power cancellation between magnet branches, the required power capacity reference value of the shared pulse power module pool meets the following conditions. ,in, This refers to the number of magnet branches. For the time frame within the predetermined runtime scenario, For the first Each magnet branch at time The pulse power is provided by the shared pulse power module.

[0021] Preferably, the engineering installation capacity of the shared pulse power module pool is based on the power capacity reference value, and is determined according to the voltage level of the shared pulse power modules, series-parallel combination requirements, power module switching dead zone, module thermal accumulation, and other factors. The backup requirements have been determined, among which, The number of shared pulse power modules required to meet the needs of normal operation scenarios.

[0022] Preferably, when a switch in the shared pulse power module or branch selection matrix fails, the coordination controller isolates the faulty device, keeps the corresponding magnet branch powered, and calls up the backup shared pulse power module; when the remaining shared pulse power module is insufficient to meet the current magnet operation requirements, it performs power derating, extends the magnet current boosting or deboosting time, suspends non-critical configuration control, or performs controlled demagnetization according to the preset magnet safety priority.

[0023] This application also discloses a cross-branch switching method for a multi-magnet shared pulse power module in a fusion device. This method is applied to a multi-magnet power supply system including branch holding power supplies for each magnet branch, a shared pulse power module pool, a series-parallel reconfigurable connection unit, and a branch selection matrix. The shared pulse power module pool includes multiple bidirectional DC / DC power modules. The series-parallel reconfigurable connection unit combines the multiple bidirectional DC / DC power modules into a shared module group. The method includes: determining the original magnet branch and the target magnet branch to be switched to in the shared module group, and confirming that the original magnet branch can maintain its magnet current through its branch holding power supply; controlling the original magnet branch... The branch maintains the power supply and establishes a freewheeling path; controls the shared module group to be switched to reduce the output voltage and output current, and disconnects the main connection switch corresponding to the original magnet branch after the output current is lower than the switching threshold and confirms electrical isolation; performs necessary series and parallel reconstruction of the shared module group to be switched according to the requirements of the target magnet branch, and performs pre-charging and voltage matching on the target magnet branch interface; after the output polarity, port voltage difference, insulation status and hardware interlock of the shared module group meet the access conditions, closes the main connection switch of the target magnet branch; controls the shared module group to perform current-limited soft start and gradually take over the pulse voltage or pulse power of the target magnet branch.

[0024] Preferably, the switching threshold is determined based on the allowable breaking current of the main connection switch, the parasitic inductance of the switching circuit, and the allowable overvoltage, and the output current of the shared module group is confirmed to be lower than the switching threshold before disconnecting the main connection switch of the original magnet branch.

[0025] Preferably, the pre-charging and voltage matching adopt at least one of the following methods: passive pre-charging with current-limiting resistor, controlled bidirectional converter pre-charging, or active voltage tracking; when multiple shared module groups supply power to different magnet branches at the same time, connection interlocking and switching dead zone verification are performed on each shared module group respectively, and the same shared pulse power module is prohibited from being allocated to two shared module groups at the same time period.

[0026] Preferably, when a switch in the shared pulse power module, series-parallel reconfigurable connection unit, or branch selection matrix fails, the faulty device is isolated and the power supply of the corresponding magnet branch is maintained to keep the magnet current; if a spare module exists, the shared module group is reconstructed and connected to the target magnet branch; if the remaining shared modules are insufficient, power derating, extending the current boost or deboost time, suspending non-critical configuration control, or controlled demagnetization are performed according to the preset magnet safety priority.

[0027] Compared with the prior art, the present invention has the following beneficial effects: Compared to the approach of configuring full-power converters separately for each magnet branch, this application establishes a continuously connected branch holding power supply in each magnet branch. This allows different power stages to handle the continuous high current holding capability and short-term high dynamic voltage and power capability of the magnet coils. Multiple bidirectional DC / DC power modules are combined into one or more electrically independent shared module groups through series-parallel reconfigurable connection units. Different module groups can serve different magnet branches simultaneously, and the same module can be reused in non-overlapping high dynamic phases of different branches. When the shared module switches between branches, the magnet current is maintained by the branch holding power supply and freewheeling channel. This, combined with module current reduction, original branch isolation, target interface pre-charging and voltage matching, output polarity and insulation status verification, and soft start, reduces the risks of current interruption, inrush current, and switching overvoltage caused by directly switching large inductive magnet loads. Furthermore, the installation capacity of the shared pulse power module can be configured according to the simultaneous pulse requirements of each magnet branch, thereby improving the utilization rate of high-power converter resources and reducing the configuration requirements of independent high-power converter equipment on the magnet side. Attached Figure Description

[0028] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a schematic diagram of the overall system topology of a multi-magnet shared power supply system for a fusion device provided in an embodiment of this application.

[0029] Figure 2 This is a schematic diagram illustrating the shared pulse power module grouping reconstruction, independent output, and multi-magnet branch connection relationship provided in the embodiments of this application.

[0030] Figure 3 A flowchart illustrating the shared pulse power module cross-magnet branch switching control method provided in this application embodiment. Detailed Implementation

[0031] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. These embodiments are used to illustrate the structural composition, connection relationships, and working process of the present invention, so that those skilled in the art can understand and implement the present invention, and are not intended to unnecessarily limit the scope of protection of the present invention.

[0032] Example 1 This embodiment provides a multi-magnet shared power supply system for a fusion device, suitable for multiple magnet branches requiring high current, bidirectional voltage regulation, and pulsed power output. The magnet branches can correspond to the poloidal field coil, central solenoid coil, vertical stabilization coil, or other magnet coils with similar power supply requirements in the fusion device.

[0033] See Figure 1 and Figure 2 The system in this embodiment includes a grid interface unit, a common medium-voltage DC bus 2, a hybrid energy storage unit 3, a shared pulse power module pool 4, a series-parallel reconfigurable connection unit 45, a branch selection matrix 5, multiple branch holding power supplies, multiple magnet coils, and a coordination controller 8. Figure 1 This shows the system-level energy connectivity. Figure 2 The diagram further illustrates the grouping and reconfiguration of the shared pulse power modules and their connection relationships with multiple magnet branches. The shared pulse power module pool 4, serving as a high-dynamic power resource shared by multiple magnet branches, can be configured into one or more electrically independent shared module groups as needed.

[0034] Figure 1 In the diagram, the branch holding power supplies for the PF1 magnet branch, PF3 magnet branch, and CS1 magnet branch are labeled as branch holding power supply 6-1, branch holding power supply 6-2, and branch holding power supply 6-3, respectively, and the corresponding magnet coils are labeled as magnet coil 7-1, magnet coil 7-2, and magnet coil 7-3, respectively.

[0035] The grid interface unit includes a main transformer 11 and a bidirectional AC / DC converter 12. The main transformer 11 connects to the AC grid and the bidirectional AC / DC converter 12, and the DC side of the bidirectional AC / DC converter 12 is connected to the common medium-voltage DC bus 2. The bidirectional AC / DC converter 12 is used to maintain the voltage of the common medium-voltage DC bus 2 and to realize bidirectional energy exchange between the AC grid and the common medium-voltage DC bus 2 according to the system operating status.

[0036] The common medium-voltage DC bus 2 constitutes the system's common energy exchange platform. The shared pulse power module pool 4, the hybrid energy storage unit 3, and the grid interface unit are all connected to the common medium-voltage DC bus 2. Multiple magnet branches obtain energy from the common medium-voltage DC bus 2 or feed energy back to it through corresponding power converters. Therefore, different magnet branches do not need to first feed all their energy back to the AC grid; energy exchange between the power-receiving and feedback branches can be achieved through the common medium-voltage DC bus 2.

[0037] Each magnet branch includes a branch holding power supply, a shared pulse power module group connected via branch selection matrix 5, and a magnet coil. The branch holding power supply is continuously connected to the corresponding magnet branch during magnet operation to carry the continuous current of the magnet branch. The shared pulse power module group and the branch holding power supply are connected in series with each other to provide the required voltage to the magnet coil.

[0038] The branch holding power supply is configured according to the continuous operation requirements of the corresponding magnet coil. Its rated current is determined according to the maximum continuous current of the corresponding magnet coil. Its rated voltage is used to cover the regulating voltage required for magnet coil resistance voltage drop, line voltage drop, magnet flat-top maintenance, or other phases where the branch holding power supply independently maintains the magnet current, as well as the holding voltage required during switching of the shared pulse power module. Therefore, the branch holding power supply does not need to bear all the high dynamic voltage requirements that occur during magnet current boosting, rapid configuration adjustment, rapid current reduction, or demagnetization.

[0039] For the For each magnet branch, the required voltage can be expressed as: ,in, For the first Each magnet branch at time The required voltage, To maintain the power supply output voltage in the branch circuit, This is the equivalent output voltage of the shared module group currently allocated to this branch. For a shared module group formed by multiple modules connected in series and parallel, the series modules determine the available output voltage level, and the parallel module chain determines the available allowable current and power capabilities. Therefore, the output voltages of the parallel modules are not algebraically added together.

[0040] During the magnet flat-top maintenance phase or other phases where the branch-held power supply can independently maintain the operation of the corresponding magnet branch, the magnet current change rate is low. The required voltage of the magnet branch is mainly used to compensate for the equivalent resistance voltage drop of the magnet coil and the line voltage drop. At this time, the branch-held power supply independently undertakes the power supply task of the corresponding magnet branch. The shared pulse power module that has been allocated to this branch exits this magnet branch and can be reallocated to other magnet branches with high dynamic power requirements.

[0041] During the magnet current boosting, rapid configuration control, rapid current reduction, or demagnetization phases, the magnet branch requires pulse voltage. The coordinating controller 8 can calculate the required voltage command for the magnet branch based on the target current command. For magnet branches that can be described using equivalent resistance and equivalent inductance, the controller can calculate the required voltage command based on the target current command. The target branch voltage command is obtained by combining the control margin. For the first The target voltage of each magnet branch. For the target magnet current, The equivalent resistance of the corresponding branch. The values ​​are the equivalent inductance of the corresponding branch. The voltage values ​​are expressed in volts (V), current values ​​in amperes (A), and resistance values ​​in ohms (Ω). Inductance is measured in Henry (H) and time in seconds (s) as the legal units of measurement.

[0042] The coordinating controller 8 determines the pulse voltage that the shared pulse power module needs to handle based on the target branch voltage and the holding voltage provided by the branch holding power supply. When the required pulse voltage is positive, the shared pulse power module injects energy into the corresponding magnet coil. When the required pulse voltage is negative, the shared pulse power module absorbs the energy released by the magnet coil and transmits this energy to the common medium-voltage DC bus 2.

[0043] The shared pulse power module pool 4 includes multiple DC / DC power modules capable of bidirectional power transmission. The input side of each DC / DC power module is connected to a common medium-voltage DC bus 2, and the output side is connected to a series-parallel reconfigurable connection unit 45. The series-parallel reconfigurable connection unit 45 can divide and combine the available power modules into one or more shared module groups according to the needs of different magnet branches. Each shared module group forms a corresponding independent output terminal. The output sides of different shared module groups remain electrically independent of each other and are respectively connected to the input terminals of different module groups in the branch selection matrix 5.

[0044] A single DC / DC power module preferably employs a circuit structure capable of bidirectional isolated power transmission and a floating output side to meet the insulation requirements of multiple module outputs connected in series. The specific combination method of multiple modules is determined based on the voltage, current, and power requirements of one or more target magnet branches. For magnet branches requiring higher pulse voltages, the coordinating controller 8 controls the series-parallel reconfigurable connection unit 45 to connect several module outputs in series to form a module chain; for magnet branches requiring higher current or power, multiple module chains that meet the voltage requirements can be connected in parallel. When multiple target magnet branches simultaneously have pulse requirements, different power modules can be combined into multiple independent shared module groups.

[0045] Before performing series-parallel reconfiguration, the operating status of the modules to be combined is detected. The module status detection unit can acquire the corresponding state quantities in the input voltage, output voltage, input current, output current, device temperature, transformer temperature, and insulation status of the respective modules. The coordination controller 8 controls the modules to be connected based on the obtained status information, ensuring that their output voltage and output polarity meet the reconfiguration conditions before controlling the establishment of the corresponding reconfiguration connection relationship, thus avoiding direct combination when the module states are mismatched.

[0046] In the shared pulse power module pool 4, individual power modules do not belong to a specific magnet branch. When a magnet branch enters a high-dynamic phase, several modules that meet its voltage, current, and power requirements can be selected to form a shared module group and connected to the branch via the branch selection matrix 5. When multiple magnet branches enter a high-dynamic phase simultaneously, different shared module groups can be connected to different magnet branches. When a magnet branch enters a phase where it can maintain its power supply independently, the corresponding shared module group exits the branch, and the power modules within it become allocable resources again.

[0047] The coordination controller 8 determines the number of series modules in the corresponding shared module group based on the voltage requirements of each target magnet branch, and determines the number of parallel module chains based on the branch current, power requirements, module rated current, and thermal state. When multiple magnet branches have pulse power requirements at the same time, the coordination controller 8 forms multiple shared module groups and allocates modules according to the priority of each branch, the duration of the requirement, the time required for module switching, the magnet current change rate, and the reserve capacity.

[0048] In one module allocation method, discrete connection state variables can be used to represent the affiliation between shared pulse power modules, shared module groups, and magnet branches within each scheduling period. During module allocation, the same shared pulse power module belongs to at most one shared module group within the same scheduling period; the total series voltage of shared module groups allocated to the same magnet branch should cover the pulse voltage requirement of that branch, and the total allowable current or total power of parallel module chains should cover the corresponding requirements. The output sides of different shared module groups remain electrically independent. Module allocation also considers module temperature, cumulative conduction time, switching dead zone, and the number of spare modules.

[0049] Branch selection matrix 5 is positioned between the independent output terminals of each shared module group and each magnet branch. Branch selection matrix 5 includes multiple module group input terminals and multiple magnet branch interfaces, including a main connection switch, a bidirectional blocking switch, a freewheeling channel, a pre-charge and voltage matching channel, and a hardware interlock unit. Branch selection matrix 5 is used to establish controlled connections between shared module groups and target magnet branches; for the same shared module group, hardware prevents it from simultaneously forming direct parallel connections with two magnet branches; for different shared module groups, they are allowed to connect to different magnet branches and operate in parallel.

[0050] In one specific structure, a controllable main connection switch is set between the input terminal of each shared module group and the interface of each magnet branch. A freewheeling channel is set on the branch side, and a pre-charge and voltage matching channel can be set on the target interface. The hardware interlock unit forms interlock conditions based on the switch auxiliary contact signal, drive enable signal, module group ownership status, and port voltage comparison signal. When the same shared module group has already established a connection with a magnet branch or does not meet the safety connection conditions, it prevents it from forming a direct parallel connection with another magnet branch. The switch status of different shared module groups is checked by their respective independent interlock links.

[0051] The pre-charge and voltage matching control unit is used to process the voltage difference between the independent output terminal of the shared module group to be connected and the target magnet branch interface before the main connection switch is closed. The voltage difference can be gradually reduced through the pre-charge switch and current-limiting resistor, or the shared module group can be controlled to actively track the target port voltage. Once the port voltage difference enters the allowable range, the pre-charge current meets the requirements, and the output polarity, insulation status, and hardware interlocking all meet the requirements, the target main connection switch is closed and the pre-charge channel is exited.

[0052] See Figure 3 For the process of switching the shared pulse power module from the original magnet branch to the target magnet branch, the coordination controller 8 first confirms that the target magnet branch has a pulse power requirement within a predetermined time window, and at the same time confirms that the original magnet branch has entered a state in which the power supply of its branch can independently maintain the magnet current.

[0053] After confirming the switching conditions, the branch holding power supply of the original magnet branch increases its output to the holding state required for the switching, and closes the bypass freewheeling switch. At this time, the branch holding power supply and the bypass freewheeling channel together provide a continuous current path for the magnet coil, so that the shared pulse power module does not need to directly cut off the current in the magnet coil during the exit process.

[0054] Subsequently, the coordinating controller 8 controls the shared pulse power module to be switched to gradually reduce its output voltage, and uses corresponding current control to gradually reduce the module's output current. Only after the shared module's output current drops below the switching current threshold is the main connection switch corresponding to the original magnet branch allowed to be disconnected.

[0055] The switching current threshold is determined based on the allowable breaking current of the main connection switch, the parasitic inductance of the magnet branch, and the allowable overvoltage. This threshold is used to limit the energy stored in the parasitic inductance at the moment of breaking and the resulting switching voltage stress. By disconnecting the original branch only after the module current has dropped to the allowable range, it is possible to avoid directly implementing shared module cross-branch switching under a large branch current.

[0056] After the main connection switch of the original magnet branch is disconnected, the coordinating controller 8 confirms that electrical isolation has been established between the shared module group to be replaced and the original magnet branch. Based on the voltage, current, and power requirements of the target magnet branch, the shared module group to be replaced is reconfigured in series and parallel as necessary. After the reconfiguration is completed and the module group status is confirmed to meet the connection conditions, the target magnet branch interface is pre-charged and voltage matched, and it is checked whether the output polarity of the shared module group is consistent with the target voltage direction of the target magnet branch. At the same time, the voltage difference, insulation status, and hardware interlock status between the independent output terminal of the shared module group to be replaced and the target magnet branch interface are checked.

[0057] Once the port voltage difference, output polarity, insulation status, and hardware interlock all meet the access conditions, the coordinating controller 8 controls the main connection switch of the target magnet branch to close. After the main connection switch closes, the shared pulse power module uses a current-limiting soft-start method to restore the output, and gradually increases the output voltage and the branch power it bears according to the allowable output voltage change rate and output current change rate of the target magnet branch.

[0058] Once the shared pulse power module has stably assumed the pulse voltage of the target magnet branch, it can exit the pre-charge channel of the target branch and, depending on the current operating status, either exit the bypass freewheeling channel or restore the branch's power supply to its normal operating point. This completes the cross-branch switching of the shared pulse power module from one magnet branch to another.

[0059] During the aforementioned switching process, the branch power supply always serves as a fixed branch power supply to maintain the continuous magnet current. The shared pulse power module primarily undertakes the tasks of high dynamic voltage and short-term high power. The functional separation of the two allows the shared pulse power module to be redistributed after it leaves the original magnet branch, without the original magnet branch needing to directly interrupt the magnet current due to the removal of the shared module.

[0060] The coordination controller 8 can perform system control in a hierarchical manner. The scenario instruction layer is used to read the pre-planned magnet discharge waveform and the real-time correction values ​​generated during operation. The function decomposition layer decomposes the voltage requirements of each magnet branch into the holding voltage component borne by the branch holding power supply and the pulse voltage component borne by the shared module group, and allows the pulse requirements of multiple target magnet branches to be formed at the same time.

[0061] Based on the functional decomposition results, the status of each power module, and the operating status of the branch, the module allocation and switching control layer determines the series-parallel combination of one or more shared module groups and their respective target magnet branches. When the target branch changes, the module allocation and switching control layer controls the operation of the series-parallel reconfigurable connection unit 45, the branch selection matrix 5, and the corresponding shared pulse power module according to the aforementioned safe switching process. The module status, branch current, branch voltage, and switch status are returned as feedback information to the coordination controller 8 for subsequent scheduling and status confirmation.

[0062] In this embodiment, a hybrid energy storage unit 3 can also be configured via a common medium-voltage DC bus 2. The hybrid energy storage unit 3 includes a battery energy storage device 21, a supercapacitor energy storage device 22, and a bidirectional energy storage converter 23. The battery energy storage device 21 is used to handle the first power component, and the supercapacitor energy storage device 22 is used to handle the second power component, fast pulse power, and transient power generated during shared module switching. The frequency of change of the first power component is lower than the frequency of change of the second power component.

[0063] During system operation, a power balance relationship is maintained between the grid side, hybrid energy storage unit 3, and each magnet branch. .in, The power exchanged from the AC power grid to the common medium-voltage DC bus 2 via the bidirectional AC / DC converter 12. For battery energy storage power, For supercapacitor energy storage power, For the first Power of each magnet branch The power loss is measured in watts (W) and the time in seconds (s).

[0064] The grid-side power control layer can set amplitude and rate-of-change limits for AC grid-side power. When the instantaneous total power of each magnet branch exceeds the power that the grid side is expected to bear, the hybrid energy storage unit 3 bears the corresponding difference. The first power component is mainly compensated by the battery energy storage device 21, while the second power component and the switching transient power are mainly compensated by the supercapacitor energy storage device 22.

[0065] When a magnet branch is in a demagnetizing or current-reducing state and releases energy to the common medium-voltage DC bus 2, this energy can preferentially supply other magnet branches that are simultaneously drawing power. If there is still residual energy, it is absorbed by the hybrid energy storage unit 3. When the absorption capacity of the hybrid energy storage unit 3 is insufficient, the residual energy is fed back to the AC grid via the bidirectional AC / DC converter 12. Through this energy flow method, the power drawing and feedback between different magnet branches during the same discharge process can be coordinated on the side of the common medium-voltage DC bus 2.

[0066] The installation capacity of the shared pulse power module pool 4 can be configured based on the actual pulse timing of multiple magnet branches. First, the current, voltage, and timing data of each magnet branch are synchronized, and then... The instantaneous power of each magnet branch is obtained. Among them, For the first Branch voltage requirements for each magnet branch For the first Current in each magnet branch.

[0067] After separating the power supplied by the branch power supply from the total power of the corresponding magnet branch, the pulse power supplied by the shared pulse power module for each magnet branch can be obtained. Without considering power cancellation between different magnet branches, the theoretical power capacity reference value of the shared pulse power module pool 4 can be calculated according to... It is confirmed that, among them, The time frame within the predetermined runtime scenario.

[0068] The above capacity relationship reflects the actual simultaneous pulse power demand of each magnet branch at the same moment, rather than simply adding up the independent peak values ​​of each magnet branch throughout the entire operating cycle. For multiple magnet branches with staggered peak times, the same set of shared pulse power modules can be reused at different time periods.

[0069] Based on the theoretical power capacity reference value, the actual engineering installation capacity is also determined by considering the module output voltage level, series and parallel combination requirements, shared module switching dead zone, module thermal accumulation, and spare module requirements. Shared pulse power module pool 4 can reserve spare modules. When allocating modules, priority can be given to modules with lower temperatures, shorter cumulative conduction times, and that meet the target branch connection conditions to avoid long-term concentration of pulse power on a few modules.

[0070] When a fault occurs in the shared pulse power module or the switch in the branch selection matrix 5, the coordination controller 8 first isolates the faulty device. Since the branch holding power supply of each magnet branch is continuously connected to the corresponding magnet coil, the branch holding power supply can continue to maintain the current of the corresponding magnet branch during the shared module exit or fault isolation process.

[0071] When available backup modules exist in the system, the coordinating controller 8 reallocates the modules and connects the backup modules that meet the conditions to the corresponding magnet branches via the branch selection matrix 5. When the remaining shared modules are insufficient to meet the original operating scenario, the coordinating controller 8 adjusts the operating status according to the preset magnet safety priority. This can reduce the power demand of the corresponding magnet branch, extend the magnet current boosting or deboosting process, suspend non-critical configuration control, or control the corresponding magnet branch to perform controlled demagnetization.

[0072] Through the above structure and working process, the long-term full current holding capacity required by each magnet branch is provided by the corresponding branch holding power supply, while the high voltage and high power capacity required during high dynamic stages are allocated sequentially by the shared pulse power module pool 4. When the shared module is reused between different magnet branches, the cross-branch switching is jointly completed by the branch holding power supply, bypass current recovery, module current reduction, original branch isolation, target branch pre-charging and voltage balancing, state verification, and soft start. This enables time-sharing sharing of high-power modules while maintaining continuous magnet current, and allows for unified coordination of power extraction, feedback, energy storage, and grid power on the common medium-voltage DC bus 2.

[0073] Example 2 This embodiment, based on Embodiment 1, further explains the specific implementation methods of the grid interface unit, the common medium-voltage DC bus 2, the hybrid energy storage unit 3, the shared pulse power module pool 4, and the branch holding power supply. The structure described in this embodiment is used to illustrate the optional implementation forms of each component without changing the decoupling principle of holding power and pulse power.

[0074] The bidirectional AC / DC converter 12 is used to connect the AC power grid and the common medium-voltage DC bus 2, and can realize bidirectional active power transmission and grid-side reactive power regulation. Depending on the system power level, voltage level and equipment configuration requirements, the bidirectional AC / DC converter 12 can adopt a two-level converter topology, a three-level NPC converter topology, a modular multi-level converter topology or other converter topologies that can realize four-quadrant operation.

[0075] The rated voltage of the common medium-voltage DC bus 2 is determined based on the input voltage of the shared pulse power module, the system insulation class, and the turns ratio of the main transformer 11. The common medium-voltage DC bus 2 is equipped with bus voltage detection, DC grounding detection, and fast DC fault isolation functions, and can isolate different bus sections via sectionalizing switches. The coordination controller 8 acquires the voltage and related status information of the common medium-voltage DC bus 2, and coordinates the operation of the grid interface unit, the hybrid energy storage unit 3, and the shared pulse power module pool 4 accordingly.

[0076] The hybrid energy storage unit 3 can be connected to the same bus segment of the common medium-voltage DC bus 2 as the shared pulse power module pool 4, or it can be connected to an independent bus segment coupled via a DC isolation converter. When using an independent bus segment, the hybrid energy storage unit 3 still exchanges energy with the common medium-voltage DC bus 2 through the corresponding DC power converter.

[0077] The battery energy storage device 21 is suitable for handling the first power component, and the supercapacitor energy storage device 22 is suitable for handling the second power component, wherein the frequency of change of the first power component is lower than the frequency of change of the second power component. When the system experiences a persistent power deficit or power surplus, the charging and discharging power of the battery energy storage device 21 can be primarily adjusted. When the system experiences rapid current rise / fall, shared module switching, or other rapid power changes, the power of the supercapacitor energy storage device 22 can be primarily adjusted.

[0078] Each bidirectional DC / DC power module in the shared pulse power module pool 4 can adopt an isolated dual active bridge structure, a modular multilevel bidirectional DC / DC structure, or other converter structures capable of bidirectional isolated power transmission and providing a floating output terminal. The input side of each module is connected in parallel to a common medium-voltage DC bus 2, and the output side is connected to a series-parallel reconfigurable connection unit 45. They can be combined into one or more shared module groups according to the needs of one or more target magnet branches.

[0079] When the voltage required by the target magnet branch is higher than the rated output voltage of a single shared pulse power module, the output terminals of multiple modules can be connected in series to form a module chain; when the current or power required by the target magnet branch is large, multiple module chains that meet the voltage requirements can be connected in parallel. When multiple magnet branches have pulse requirements at the same time, the series-parallel reconfigurable connection unit 45 divides different modules into different shared module groups. Before reconfiguration, the module status detection unit detects the output voltage, current, temperature, and insulation status of the modules to be combined, and the coordinating controller 8 establishes the reconfigurable connection relationship after each module meets the corresponding connection conditions.

[0080] When different shared pulse power modules use the same rated parameters, different output voltage and power levels can be achieved by changing the number of series modules and parallel module chains within each shared module group. Different shared module groups can form independent output terminals at the same time and connect to different magnet branches respectively. With this modular approach, it is not necessary to configure an independent high-power converter capable of covering all peak requirements for each magnet branch.

[0081] Branch holding power supplies are used to continuously carry the operating current of the corresponding magnet coil. Branch holding power supplies can be low-voltage high-current bidirectional choppers, multi-phase interleaved parallel DC / DC converters, combinations of thyristor rectifier bridges and low-voltage choppers, or other power supply structures capable of continuously carrying magnet current and bidirectional regulation.

[0082] To reduce conduction losses during the branch holding phase, the branch holding power supply can also be equipped with low on-state voltage drop bypass devices and redundant freewheeling paths. When the magnet branch is in flat-top holding or other low-dynamic states, the branch holding power supply provides the low voltage and high current required for continuous operation of the magnet coil. The shared pulse power module then exits this magnet branch and can rejoin the high-dynamic power supply of other magnet branches.

[0083] Example 3 Based on Embodiment 1, this embodiment further explains the hierarchical control of the coordination controller 8 and the power coordination process between the grid side and the hybrid energy storage unit 3.

[0084] The coordination controller 8 includes a scenario command layer, a function decomposition layer, a grid-side power control layer, a module allocation and switching control layer, and a hybrid energy storage control layer. These control layers interact with each other through control data and status data to jointly complete magnet branch demand analysis, shared module scheduling, grid-side power regulation, and energy storage power allocation.

[0085] The scenario command layer acquires the pre-planned magnet discharge waveform of the fusion device and receives real-time correction values ​​generated during operation. From this, the target current or corresponding control requirements of each magnet branch as a function of time can be obtained.

[0086] The functional decomposition layer calculates the corresponding branch voltage requirements based on the target operating state of each magnet branch, and decomposes the branch voltage requirements into holding components and pulse components. The holding component is handled by the corresponding branch holding power supply, and the pulse component is handled by the shared pulse power module.

[0087] For the Each magnet branch has an instantaneous power that can be calculated according to... Confirmed. Among them, For the first Each magnet branch at time power, To meet the branch voltage requirements of the corresponding branch, This corresponds to the current in the magnet branch.

[0088] The module allocation and switching control layer determines the module allocation scheme based on the pulse voltage and pulse power requirements of each magnet branch within a rolling time window. Module allocation can comprehensively consider the number of shared pulse power modules, the number of module switching operations, module temperature rise differences, magnet branch voltage tracking status, and reserve margin.

[0089] When multiple magnet branches generate pulse demands simultaneously, the module allocation and switching control layer first determines the number of series modules and parallel module chains required for the shared module group of each target magnet branch. Then, according to the magnet operation priority, demand duration, switching time, magnet current change rate, and spare module conditions, different shared pulse power modules are divided into different shared module groups and allocated to the corresponding magnet branches.

[0090] After allocation is completed, the module allocation and switching control layer sends control commands to the series-parallel reconfigurable connection unit 45, the branch selection matrix 5, and the corresponding shared pulse power modules within each shared module group. After each executing device completes its action, it returns the switch status, module group connection status, module operating status, and branch current and voltage status to the coordination controller 8. The coordination controller 8 then confirms the electrical independence between each module group and the corresponding branch connection status, and proceeds to the subsequent control process.

[0091] The grid-side power control layer generates the grid-side target power based on the current magnet load, system losses, and energy storage status. The grid-side target power meets the grid-side rated capacity and power change rate requirements, i.e. and to The rate of change over time is limited.

[0092] Given the target power on the grid side, the remaining power that hybrid energy storage unit 3 needs to handle can be expressed as follows: .in, The total power that needs to be balanced for hybrid energy storage unit 3 This represents the system's power loss.

[0093] Hybrid energy storage control layer can be based on Power command to form battery energy storage device 21 Power commands for supercapacitor energy storage device 22 Power distribution can be performed according to the time scale of power change, so that the first power component is mainly borne by the battery energy storage device 21, and the second power component is mainly borne by the supercapacitor energy storage device 22.

[0094] The aforementioned power allocation can be achieved using frequency decomposition, model predictive control, or optimized allocation methods. All different allocation methods are based on meeting grid-side power constraints, energy storage system state limitations, and the normal operation requirements of the magnet branch.

[0095] When the state of charge of the battery energy storage device 21 approaches the upper or lower limit of the allowable limit, the hybrid energy storage control layer correspondingly reduces the charging or discharging power of the battery energy storage device 21, and the supercapacitor energy storage device 22 or the AC grid undertakes more power. When the terminal voltage of the supercapacitor energy storage device 22 approaches its operating limit, the coordination controller 8 adjusts the power undertaken by the battery energy storage device 21 and the grid side, so that the supercapacitor energy storage device 22 restores the corresponding energy regulation margin.

[0096] At the end of a complete magnet discharge cycle, the energy storage state of the hybrid energy storage unit 3 can be restored to a predetermined range through terminal energy closure constraint, so as to avoid the energy storage energy gradually deviating from the normal operating range during multiple consecutive discharge cycles.

[0097] When a magnet branch is in feedback mode, the energy it releases first enters the common medium-voltage DC bus 2. If other magnet branches are absorbing energy at the same time, the feedback energy can be preferentially utilized by these other magnet branches. If other magnet branches cannot fully absorb the energy, the remaining energy is absorbed by the hybrid energy storage unit 3. When the hybrid energy storage unit 3 can no longer absorb energy, the remaining energy is fed back to the AC grid by the bidirectional AC / DC converter 12.

[0098] Therefore, grid-side power control, hybrid energy storage power distribution, and energy exchange between multiple magnet branches are all coordinated through the common medium-voltage DC bus 2. The system can limit the peak power and rapid power changes of the AC grid, and also reduce the round-trip transmission of magnet feedback energy in different energy conversion stages.

[0099] Example 4 This embodiment further explains the capacity configuration process of the shared pulse power module pool 4 and the grid-side and hybrid energy storage unit 3.

[0100] First, the current and voltage data of each magnet branch are acquired in a predetermined operating scenario, and the data of different magnet branches are synchronized in time and uniformly sampled. The instantaneous power of each magnet branch is calculated based on its voltage and current.

[0101] According to the sign convention that power is positive when a magnet absorbs energy and negative when a magnet releases energy, the first... The power of each magnet branch is .

[0102] The system's signed net power can be expressed as .in, For auxiliary load power, This represents the system's power loss.

[0103] The instantaneous absolute power flux on the magnet side can be expressed as Signed net power reflects the net power that the AC grid and energy storage system actually need to balance, while instantaneous absolute power flux reflects the actual power flux that the magnet-side power converter needs to handle.

[0104] For the Each magnet branch maintains the power supply voltage according to the predetermined operating scenario. The maximum value can be determined either by the preset power supply load ratio. This represents the voltage drop across the equivalent resistance of the magnet coil. This indicates the voltage drop across the line. This indicates the voltage margin required for control.

[0105] After determining the voltage and power to be borne by the branch holding power supply, the portion of the total power of the magnet branch that is borne by the branch holding power supply is separated to obtain the pulse power that the corresponding shared pulse power module needs to bear. .

[0106] The theoretical capacity of the shared pulse power module pool 4 is not determined by simply summing the maximum pulse power of each magnet branch, but by determining the actual pulse power demand of all magnet branches at the same time.

[0107] Without considering power cancellation between different magnet branches, the reference value for the power capacity of the shared pulse power module pool 4 can be expressed as follows: ,in, The time within the predetermined running scenario time range.

[0108] Actual capacity configuration must also meet module output polarity and series-parallel reconfiguration conditions. If the pulse voltage required by a magnet branch exceeds the output capacity of a single module, a sufficient number of series modules must be configured. If a single series chain cannot meet the target power or allowable current requirements, a parallel module chain is further configured.

[0109] Capacity configuration variables may include grid-side rated power, grid-side smoothing time scale, rated power and rated energy of battery energy storage device 21, rated power and rated energy of supercapacitor energy storage device 22, rated voltage of each branch holding power supply, single-module rated parameters of shared pulse power module, number of shared modules, and number of spare modules.

[0110] When determining candidate capacity configurations, at least two of the following can be considered: lifecycle cost, grid-side rated capacity, magnet-side installed capacity, energy storage lifespan loss, and number of shared module replacements. When verifying the obtained candidate configurations, the energy deviation of the energy storage terminal at the end of one operating cycle is first addressed to ensure that the energy storage status meets the requirements of cycle operation.

[0111] Subsequently, the voltage and current capabilities of the shared pulse power module, module switching dead zone, module thermal accumulation, DC fault isolation, and backup requirements were verified. For candidate configurations that did not meet the above conditions, the corresponding capacity or number of modules was readjusted until a configuration scheme that meets the electrical operation and safety requirements was obtained.

[0112] The installed capacity of the project can also reserve backup capacity based on the theoretical lower limit. For projects using... Configuration of the backup principle, To meet the required number of shared pulse power modules for normal operation, at least one backup module is also configured for fault replacement. In the event of a single module failure, the coordination controller 8 can isolate the faulty module and reconfigure the backup module to the corresponding magnet branch.

[0113] By using the above capacity configuration method, the theoretical lower limit, the engineering feasible capacity that meets the actual connection and switching constraints, and the engineering installation capacity including safety reserves can be determined respectively, so that the capacity configuration corresponds to the actual operation sequence of multiple magnet branches.

[0114] Example 5 This embodiment further explains the time-division multiplexing process of the shared pulse power module across branches, taking into account the situation where multiple magnet branches have pulse power requirements at different time periods.

[0115] In this embodiment, the shared pulse power module pool 4 contains multiple shared pulse power modules that can be reallocated. To illustrate the allocation relationship of the modules in different time periods, four of the shared pulse power modules are denoted as follows: , , and .

[0116] During the first time period, the PF1 magnet branch is in the current-increasing phase, requiring a higher forward pulse voltage. Here, PF represents the poloidal field. The coordinating controller 8, based on the voltage and power requirements of the PF1 magnet branch, will share the pulse power module. , and The power is distributed to the PF1 magnet branch. The distributed modules are connected in series and parallel as needed, and are connected in series with the PF1 magnet branch to supply power to the PF1 magnet coil.

[0117] After the PF1 magnet branch completes its current boost and enters the flat-top sustaining phase, its current change rate decreases. At this time, the PF1 magnet branch is mainly maintained independently by the corresponding branch's power supply. Shared pulse power module. , and Exit the PF1 magnet branch according to the safe switching process described in Example 1 and return to the shared resource state.

[0118] Upon entering the second phase, the PF3 magnet branch requires rapid configuration adjustment. The coordinating controller 8, based on the voltage and power requirements of the PF3 magnet branch, will share the pulse power module. , and Reassigned to the PF3 magnet branch.

[0119] During the process of the module connecting to the PF3 magnet branch from its original connection state, the original magnet branch's power supply first takes over the corresponding maintenance tasks. After the shared module reduces voltage and current and completes the isolation of the original branch, it pre-charges and equalizes the voltage at the PF3 magnet branch interface. After confirming that the output polarity, port voltage difference, insulation status, and hardware interlock meet the connection conditions, the main connection between the module and the PF3 magnet branch is established, and the module output is increased through soft start.

[0120] In the third time period, the CS1 magnet branch enters the demagnetization phase, requiring the shared pulse power module to provide a reverse voltage and absorb the energy released by the magnet. Here, CS represents the central solenoid. The coordinating controller 8 will use the shared pulse power module... , and Assign it to the CS1 magnet branch and make the corresponding module operate according to the output polarity required for the demagnetization of the CS1 magnet branch.

[0121] The energy released by the CS1 magnet branch is transmitted to the common medium-voltage DC bus 2 via the allocated shared pulse power module. If other magnet branches are drawing power at the same time, the energy can be preferentially utilized by those other magnet branches. The remaining energy can enter the hybrid energy storage unit 3. When the absorption capacity of the hybrid energy storage unit 3 is insufficient, it is fed back to the AC grid via the bidirectional AC / DC converter 12.

[0122] During module allocation, the coordinating controller 8 can prioritize modules with lower temperatures, shorter cumulative conduction times, and that meet the target branch connection conditions, while retaining corresponding spare modules. By balancing the usage time and thermal state of different modules, the concentrated heat load caused by the same group of modules repeatedly bearing high pulse power for a long time can be reduced.

[0123] During the three time periods mentioned above, the shared pulse power module Participated in the high-dynamic power supply of the PF1 magnet branch, PF3 magnet branch, and CS1 magnet branch. Shared pulse power module. They participate in the PF1 magnet branch and CS1 magnet branch respectively, sharing the pulse power module. They participate in the PF3 magnet branch and the CS1 magnet branch, respectively. The same shared module can thus be reused in multiple non-overlapping high-power stages.

[0124] When a shared pulse power module or its corresponding connection switch fails, the coordinating controller 8 isolates the faulty device and ensures that the affected branch continues to maintain magnet current. If a backup module is available, it is retrieved from the shared pulse power module pool 4 and reconnected to the corresponding target magnet branch according to the safe switching procedure.

[0125] If the remaining available modules are insufficient to meet the original magnet discharge scenario, the coordinating controller 8 reduces the power demand of the corresponding branch according to the preset magnet safety priority, or extends the magnet current boost and deboost times. For non-critical configuration control, the corresponding fast adjustment task can be paused. When it is necessary to terminate magnet operation, the corresponding magnet branch can be demagnetized in a controlled manner, thereby avoiding direct interruption of magnet current when shared module resources are insufficient.

[0126] This embodiment utilizes the temporal staggering of the high-dynamic phases of the magnet branches to allow the same shared pulse power module to be sequentially configured to different magnet branches. Each magnet branch maintains the ability to continuously carry the continuous current of that branch, and the shared pulse power module only enters the target magnet branch during the corresponding high-dynamic phase. Therefore, the withdrawal and redistribution of the shared module does not require interrupting the magnet coil current, and it can transform the short-term high-power conversion capability originally fixed to a single magnet branch into a system-level resource shared by multiple magnet branches.

[0127] Example 6 See Figure 2 This embodiment illustrates the grouping method of shared modules when multiple magnet branches simultaneously have pulse power requirements. It uses six shared pulse power modules. to For example, when both the PF1 magnet branch and the CS1 magnet branch require high dynamic power during a certain scheduling period, the coordination controller 8 can... to Combined into shared module group A, to Combined into shared module group B, and retaining As a backup module, shared module group A forms an independent output terminal 46a and is connected to the PF1 magnet branch via branch selection matrix 5, and shared module group B forms an independent output terminal 46b and is connected to the CS1 magnet branch via branch selection matrix 5.

[0128] During the simultaneous power supply process described above, the branches of PF1 and CS1 maintain a continuous power supply connection to the corresponding magnet branches and undertake the task of maintaining continuous current. Shared module group A and shared module group B respectively undertake the high dynamic voltage or pulse power tasks of the two branches. Since the output sides of the two shared module groups are electrically independent of each other, they can work simultaneously; the same shared pulse power module belongs to only one of the shared module groups during the same scheduling period.

[0129] When the PF1 magnet branch finishes its high-dynamic phase and the PF3 magnet branch subsequently generates a pulse demand, the aforementioned safe switching process can be performed on shared module group A while shared module group B continues to serve the CS1 magnet branch, and it can be reconfigured to the PF3 magnet branch. Thus, the shared module pool can handle simultaneous pulse demands from multiple branches and can also utilize the time misalignment of the high-dynamic phases of different branches to achieve cross-branch reuse.

[0130] The technical solution of the present invention has been described above with reference to specific embodiments. The technical features in each embodiment can be combined and used together without technical conflict. Based on the technical content disclosed in this application, those skilled in the art can make corresponding adjustments or equivalent substitutions to the specific converter topology of the shared pulse power module, the implementation form of the branch selection switch, the energy storage medium, the number of magnet branches, the number of modules, and the control implementation method without departing from the technical concept of the present invention. The above adjustments or substitutions do not change the basic technical relationship whereby the branch-maintaining power supply undertakes the continuous current maintenance function, the shared pulse power module undertakes the high dynamic pulse power function, and the shared module achieves safe allocation and switching across magnet branches through the branch selection matrix. Other equivalent implementation methods that those skilled in the art can directly obtain based on the disclosure of this application can be implemented according to the actual fusion device and magnet power supply requirements.

Claims

1. A multi-magnet shared power supply system for a fusion device, characterized in that, The system includes a common medium-voltage DC bus, a shared pulse power module pool, a series-parallel reconfigurable connection unit, a branch selection matrix, multiple magnet branches, and a coordination controller. Each magnet branch includes a branch holding power supply and a magnet coil. The branch holding power supply is continuously connected to the corresponding magnet branch during magnet operation to provide the holding voltage and current path required to maintain the continuous magnet current. The shared pulse power module pool includes multiple bidirectional DC / DC power modules. The input side of each power module is connected to the common medium-voltage DC bus, and the output side is connected to the series-parallel reconfigurable connection unit. The series-parallel reconfigurable connection unit combines multiple bidirectional DC / DC power modules into one or more electrically independent shared module groups according to the voltage, current, or power requirements of one or more target magnet branches. Each shared module group has an independent output... The output end is selectively connected to the corresponding target magnet branch via the branch selection matrix. When the shared module group is connected to the target magnet branch, it forms a series voltage superposition relationship with the corresponding branch power supply and jointly supplies power to the magnet coil. The branch power supply bears the holding voltage component required for the continuous maintenance of the magnet current, and the shared module group bears the pulse voltage or pulse power component required for the magnet current boosting, fast configuration control, fast current reduction or demagnetization stages. The coordination controller determines the composition of the shared module group and the target magnet branch according to the operating stage and pulse requirements of each magnet branch. During the period when the shared module group exits the original magnet branch or switches to another target magnet branch, it controls the original magnet branch to establish a continuous current path, so that the shared pulse power module can be time-division multiplexed among multiple magnet branches, and different shared module groups can be connected to different magnet branches at the same time.

2. The multi-magnet shared power supply system for fusion devices according to claim 1, characterized in that, The rated current of the branch holding power supply is determined according to the maximum continuous current of the corresponding magnet coil. The rated voltage of the branch holding power supply is used to cover the magnet coil resistance voltage drop, line voltage drop, the adjustment voltage required for magnet flat-top maintenance or the independent maintenance of magnet current by the branch holding power supply, and the holding voltage during the switching of the shared pulse power module.

3. The multi-magnet shared power supply system for fusion devices according to claim 1, characterized in that, Each of the bidirectional DC / DC power modules has an output terminal that is electrically isolated from each other and can be floated; the series-parallel reconfigurable connection unit connects multiple power modules in series to form a module chain to improve the output voltage of the shared module group, and connects one or more module chains that meet the voltage requirements in parallel to improve the output current or power capability of the shared module group; any shared pulse power module belongs to only one shared module group in the same scheduling period.

4. The multi-magnet shared power supply system for a fusion device according to claim 1, characterized in that, The branch selection matrix is ​​equipped with module group input terminals corresponding to the independent output terminals of each shared module group and branch interfaces corresponding to each magnet branch, and includes a main connection switch, a bidirectional blocking switch, a freewheeling channel, a precharge and voltage matching channel, and a hardware interlocking unit; the hardware interlocking unit restricts the same shared module group from forming a direct electrical connection with two magnet branches at the same time, while allowing different shared module groups to connect to different magnet branches respectively.

5. The multi-magnet shared power supply system for a fusion device according to claim 4, characterized in that, When the shared module group is switched from the original magnet branch to the target magnet branch, the coordination controller performs the following actions in sequence: keeping the original magnet branch in a power-up and holding state and establishing a freewheeling path; controlling the shared module group to be switched to reduce voltage and current; disconnecting the main connection switch corresponding to the original magnet branch and confirming electrical isolation after the output current of the shared module group is lower than the switching threshold. Perform pre-charging and voltage matching on the target magnet branch interface; close the main connection switch of the target magnet branch after the output polarity, port voltage difference, insulation status and hardware interlock meet the access conditions; control the current limiting soft start of the shared module group and restore the target pulse power.

6. The multi-magnet shared power supply system for a fusion device according to claim 5, characterized in that, The switching threshold is determined based on the allowable breaking current of the main connection switch, the parasitic inductance of the switching circuit, and the allowable overvoltage; the pre-charging and voltage matching are achieved through at least one of the following methods: current-limiting resistor pre-charging, controlled bidirectional converter pre-charging, or active voltage tracking; after the target magnet branch is connected, the coordination controller controls the soft start of the shared module group according to the allowable output voltage change rate and output current change rate of the target magnet branch.

7. The multi-magnet shared power supply system for a fusion device according to claim 1, characterized in that, The coordination controller collects the current and voltage of each magnet branch, the voltage of the common medium-voltage DC bus, the temperature and insulation status of each shared pulse power module, and the switching status of the branch selection matrix. When one or more magnet branches have pulse power requirements, the module composition and target magnet branch of each shared module group are determined according to the voltage requirements, power requirements, operating priorities, requirement duration, module switching time, magnet current change rate, and spare module capacity of each magnet branch.

8. The multi-magnet shared power supply system for a fusion device according to claim 7, characterized in that, The allocation of the shared pulse power modules satisfies the following: the same shared pulse power module is allocated to at most one shared module group during the same scheduling period; the total series voltage of each shared module group covers the pulse voltage requirement of the corresponding target magnet branch, and the total allowable current or total power of each parallel module chain covers the current or power requirement of the corresponding target magnet branch; different shared module groups maintain electrical independence on the output side; the coordination controller also determines the shareable pulse power modules based on the temperature and cumulative conduction time of each shared pulse power module, the switching dead zone of the shared module group, and the number of spare modules.

9. The multi-magnet shared power supply system for a fusion device according to claim 1, characterized in that, It also includes a grid interface unit and a hybrid energy storage unit; the grid interface unit includes a main transformer and a bidirectional AC / DC converter, the AC side of the bidirectional AC / DC converter is connected to the AC grid via the main transformer, and the DC side is connected to the common medium-voltage DC bus; the hybrid energy storage unit includes a battery energy storage device, a supercapacitor energy storage device and a bidirectional energy storage converter, the battery energy storage device and the supercapacitor energy storage device are connected to the common medium-voltage DC bus via the bidirectional energy storage converter.

10. The multi-magnet shared power supply system for a fusion device according to claim 9, characterized in that, The battery energy storage device is used to handle the first power component, and the supercapacitor energy storage device is used to handle the second power component, the fast pulse power, and the transient power during the switching process of the shared pulse power module, wherein the change frequency of the first power component is lower than the change frequency of the second power component.

11. The multi-magnet shared power supply system for a fusion device according to claim 10, characterized in that, The coordination controller sets amplitude and rate of change limits for the grid-side power of the bidirectional AC / DC converter, allocates the first power component of the power difference exceeding the grid-side capacity to the battery energy storage device, and allocates the second power component to the supercapacitor energy storage device. When the magnet branch releases energy, it first supplies the released energy to other magnet branches that are simultaneously drawing power, and secondly it is used to charge the hybrid energy storage unit. When the absorption capacity of the hybrid energy storage unit is insufficient, the energy is fed back to the AC grid through the bidirectional AC / DC converter.

12. The multi-magnet shared power supply system for a fusion device according to claim 1, characterized in that, The capacity of the shared pulse power module pool is determined according to the simultaneous pulse power requirements of each magnet branch. Without considering power cancellation between magnet branches, the reference value for the required power capacity of the shared pulse power module pool meets the following requirements: ,in, This refers to the number of magnet branches. For the time frame within the predetermined runtime scenario, For the first Each magnet branch at time The pulse power is provided by the shared pulse power module.

13. The multi-magnet shared power supply system for a fusion device according to claim 12, characterized in that, The engineering installation capacity of the shared pulse power module pool is based on the power capacity reference value, taking into account the voltage level of the shared pulse power modules, series and parallel combination requirements, power module switching dead zone, module thermal accumulation, and other factors. The backup requirements have been determined, among which, The number of shared pulse power modules required to meet the needs of normal operation scenarios.

14. The multi-magnet shared power supply system for a fusion device according to claim 1, characterized in that, When a fault occurs in the shared pulse power module or the switch in the branch selection matrix, the coordination controller isolates the faulty device, keeps the corresponding magnet branch powered and calls the backup shared pulse power module. When the remaining shared pulse power module is insufficient to meet the current magnet operation requirements, power derating, extending the magnet current boosting or deboosting time, suspending non-critical configuration control, or controlled demagnetization are performed according to the preset magnet safety priority.

15. A method for cross-branch switching of a shared pulse power module for multiple magnets in a fusion device, applied to a multi-magnet power supply system including branch holding power supplies for each magnet branch, a shared pulse power module pool, a series-parallel reconfigurable connection unit, and a branch selection matrix, wherein the shared pulse power module pool includes multiple bidirectional DC / DC power modules, and the series-parallel reconfigurable connection unit combines the multiple bidirectional DC / DC power modules into a shared module group, characterized in that... include: Identify the original magnet branch and the target magnet branch of the shared module group to be replaced, and confirm that the original magnet branch can maintain the magnet current by its branch power supply. The branch controlling the original magnet branch maintains the power supply in a holding state and establishes a freewheeling path; The system controls the shared module group to be switched to reduce its output voltage and current. After the output current falls below the switching threshold, it disconnects the main connection switch corresponding to the original magnet branch and confirms electrical isolation. Based on the requirements of the target magnet branch, the system performs necessary series-parallel reconfiguration of the shared module group to be switched and performs pre-charging and voltage matching on the target magnet branch interface. After the shared module group's output polarity, port voltage difference, insulation status, and hardware interlock meet the access conditions, the system closes the main connection switch of the target magnet branch. The system controls the shared module group to perform current-limited soft start and gradually assume the pulse voltage or pulse power of the target magnet branch.

16. The method for switching across branches according to claim 15, characterized in that, The switching threshold is determined based on the allowable breaking current of the main connection switch, the parasitic inductance of the switching circuit, and the allowable overvoltage. Before disconnecting the main connection switch of the original magnet branch, it is confirmed that the output current of the shared module group is lower than the switching threshold.

17. The method for switching across branches according to claim 15, characterized in that, The pre-charging and voltage matching adopt at least one of the following methods: passive pre-charging with current-limiting resistor, controlled bidirectional converter pre-charging, or active voltage tracking; when multiple shared module groups supply power to different magnet branches at the same time, connection interlocking and switching dead zone verification are performed on each shared module group respectively, and the same shared pulse power module is prohibited from being allocated to two shared module groups at the same time period.

18. The method for switching across branches according to claim 15, characterized in that, When a switch in the shared pulse power module, series-parallel reconfigurable connection unit, or branch selection matrix fails, the faulty device is isolated and the corresponding magnet branch maintains the magnet current by keeping the power supply. If a spare module exists, the shared module group is reconstructed and connected to the target magnet branch. If the remaining shared modules are insufficient, power derating, extending the current boost or deboost time, suspending non-critical configuration control, or controlled demagnetization are performed according to the preset magnet safety priority.

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