Power supply system
Patent Information
- Application Number
- CN202611120692.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-27
- Publication Date
- 2026-10-16
AI Technical Summary
[0015]In summary, this power supply system, by communicating with the management unit and the DC bus, utilizes the physical characteristic of a sharp voltage drop on the bus during a short circuit to construct an active identification mechanism for DC bus short-circuit faults. Specifically, when the management unit detects an abnormal DC bus voltage within a preset protection voltage range, it can identify bus short-circuit faults that traditional overcurrent protection devices cannot detect. It then controls the first and second protection modules to disconnect, completely cutting off the energy injection path to the bus at its source, achieving active and reliable fault isolation. Thus, this power supply system can still promptly detect bus short-circuit faults even when a short circuit occurs on the high-voltage DC bus and the self-protection of each power module results in insufficient short-circuit current, thereby improving the reliability of the power supply system.
Smart Images
Figure CN122931602A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of power supply system technology, and in particular to a power supply system. Background Technology
[0002] In DC power supply systems, such as those using an 800V high-voltage DC bus, multiple power sources (such as AC converters) and energy storage battery units are typically connected in parallel to supply power to the bus to support high-power loads. In the event of a short circuit in a branch, the bus provides short-circuit capacity, and the energy from the AC converter and battery units contributes to the short-circuit current, sufficient to trigger the appropriate protective devices (such as circuit breakers or fuses) to disconnect the faulty branch.
[0003] However, new protection challenges arise when a short circuit occurs on the DC bus itself. Modern power electronic converters (such as AC / DC or DC / DC converters) generally have built-in fast overcurrent protection. Once an output short circuit is detected, they immediately activate current limiting or directly cut off the output for self-protection. This means that after a short circuit, the total current from all converters on the bus does not change significantly, resulting in limited short-circuit capacity. Therefore, the main protection device installed on the bus or at the power output often fails to detect an overcurrent sufficient to trigger it, and the protection devices in each branch circuit (such as the protection switches at the converter output) also fail to operate effectively. The inability to detect a bus short circuit in a timely manner may lead to the fault persisting, causing the entire system to fail or be damaged, resulting in low reliability. Summary of the Invention
[0004] The main objective of this application is to propose a power supply system that can promptly detect bus short-circuit faults even when a short circuit occurs on the high-voltage DC bus and the short-circuit current is insufficient due to self-protection of each power module, thereby improving the reliability of the power supply system.
[0005] To achieve the above objectives, the power supply system proposed in this application includes: A power input circuit, the power input circuit having a first power module and a first protection module, one end of the first power module being used to connect to a power source, the other end of the first power module being connected to one end of the first protection module, and the other end of the first protection module being connected to a DC bus. A battery unit, comprising a battery module, a second power module, and a second protection module, wherein one end of the second power module is connected to the battery module, the other end of the second power module is connected to one end of the second protection module, and the other end of the second protection module is connected to a DC bus. The first protection module and the second protection module are used to disconnect when the current flowing through them reaches the overcurrent trip threshold; A management unit is connected to the DC bus. The management unit is used to control the first protection module and the second protection module to disconnect when a first preset short-circuit protection condition is met. The first preset short-circuit protection condition includes: the voltage of the DC bus is within a preset protection voltage range.
[0006] In one embodiment, the management unit is further connected to the first power module and the second power module, respectively; The management unit is used to control the first protection module and the second protection module to disconnect after a first time period when the first preset short circuit protection condition and the second preset short circuit protection condition are simultaneously met. The second preset short-circuit protection condition includes: the management unit obtains status alarm information issued by the first power module and / or the second power module, the status alarm information including at least one of output low voltage alarm, output overload alarm or output short circuit alarm.
[0007] In one embodiment, the management unit is used to control the first protection module and the second protection module to disconnect after a second delay when both the first preset short-circuit protection condition and the third preset short-circuit protection condition are simultaneously met. The third preset short-circuit protection condition includes: the management unit obtaining insulation fault alarm information of the DC bus.
[0008] In one embodiment, the management unit is also connected to the first protection module and the second protection module; The management unit is used to control the first protection module and the second protection module to disconnect after a third time period when both the first preset short-circuit protection condition and the fourth preset short-circuit protection condition are met simultaneously. The fourth preset short-circuit protection condition includes the first protection module and the second protection module being in an undisconnected state.
[0009] In one embodiment, the management unit is used to control the first protection module and the second protection module to disconnect directly when the first preset short-circuit protection condition, the second preset short-circuit protection condition, the third preset short-circuit protection condition and the fourth preset short-circuit protection condition are met simultaneously. The second preset short-circuit protection condition includes: the management unit obtains status alarm information issued by the first power module and / or the second power module, the status alarm information including at least one of output low voltage alarm, output overload alarm or output short circuit alarm; The third preset short-circuit protection condition includes: the management unit obtaining insulation fault alarm information of the DC bus; The fourth preset short-circuit protection condition includes the fact that both the first protection module and the second protection module are in an undisconnected state.
[0010] In one embodiment, the first power module includes a plurality of power converters, the first protection module includes a plurality of first switching devices, the plurality of power converters are connected one-to-one with the plurality of first switching devices, the plurality of power converters are used to access a power source, and the first switching devices are connected to the DC bus.
[0011] In one embodiment, the second power module includes multiple voltage converters, the second protection module includes multiple second switching devices, and the battery module includes multiple battery devices. Multiple battery devices, multiple voltage converters, and multiple second switching devices are connected in series one-to-one, wherein each battery device is connected to one end of the corresponding voltage converter, the other end of the voltage converter is connected to one end of the corresponding second switching device, and the other end of the second switching device is connected to the DC bus.
[0012] In one embodiment, the management unit is connected to multiple power converters, multiple voltage converters, multiple first switching devices, and multiple second switching devices respectively. The management unit is used to control all the first switching devices and all the second switching devices to disconnect after a fourth time period when the first preset short circuit protection condition, the second preset short circuit protection condition, and the fourth preset short circuit protection condition are simultaneously met. The second preset short-circuit protection condition specifically includes: the management unit obtaining status alarm information issued by at least one of the power converters, and / or the management unit obtaining status alarm information issued by at least one of the voltage converters; The fourth preset short-circuit protection condition specifically includes: all the first switching devices and all the second switching devices are in an undisconnected state.
[0013] In one embodiment, the power supply system further includes a power output circuit, the input terminal of which is connected to the DC bus, and the output terminal of which is used to connect to the target load. The power output circuit includes a DC-DC converter or a DC-AC converter.
[0014] In one embodiment, the minimum value of the preset protection voltage range of the DC bus is greater than or equal to 0V, and the maximum value of the preset protection voltage range is less than or equal to the minimum operating voltage of the target load.
[0015] In summary, this power supply system, by communicating with the management unit and the DC bus, utilizes the physical characteristic of a sharp voltage drop on the bus during a short circuit to construct an active identification mechanism for DC bus short-circuit faults. Specifically, when the management unit detects an abnormal DC bus voltage within a preset protection voltage range, it can identify bus short-circuit faults that traditional overcurrent protection devices cannot detect. It then controls the first and second protection modules to disconnect, completely cutting off the energy injection path to the bus at its source, achieving active and reliable fault isolation. Thus, this power supply system can still promptly detect bus short-circuit faults even when a short circuit occurs on the high-voltage DC bus and the self-protection of each power module results in insufficient short-circuit current, thereby improving the reliability of the power supply system. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0017] Figure 1 A schematic diagram of an embodiment of the power supply system provided in this application; Figure 2 A schematic diagram of yet another embodiment of the power supply system provided in this application; Figure 3 A schematic diagram of yet another embodiment of the power supply system provided in this application; Figure 4 A schematic diagram of another embodiment of the power supply system provided in this application is shown.
[0018] Explanation of icon numbers: 10. Power input circuit; 11. First power module; 12. First protection module; 13. Power converter; 14. First switching device; 20. Battery cell; 21. Second power module; 22. Second protection module; 23. Battery module; 24. Voltage converter; 25. Battery device; 26. Second switching device; 30. Management unit; 40. Power output circuit; 50. DC bus.
[0019] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0021] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.
[0022] In DC power supply systems, such as those using an 800V high-voltage DC bus, multiple power sources (such as AC converters) and energy storage battery units are typically connected in parallel to supply power to the bus to support high-power loads. In the event of a short circuit in a branch, the bus provides short-circuit capacity, and the energy from the AC converter and battery units contributes to the short-circuit current, sufficient to trigger the appropriate protective devices (such as circuit breakers or fuses) to disconnect the faulty branch.
[0023] However, new protection challenges arise when a short circuit occurs on the DC bus itself. Modern power electronic converters (such as AC / DC or DC / DC converters) generally have built-in fast overcurrent protection. Once an output short circuit is detected, they immediately activate current limiting or directly cut off the output for self-protection. This means that after a short circuit, the total current from all converters on the bus does not change significantly, resulting in limited short-circuit capacity. Therefore, the main protection device installed on the bus or at the power output often fails to detect an overcurrent sufficient to trigger it, and the protection devices in each branch circuit (such as the protection switches at the converter output) also fail to operate effectively. The inability to detect a bus short circuit in a timely manner may lead to the fault persisting, causing the entire system to fail or be damaged, resulting in low reliability.
[0024] To address the aforementioned issues, this application provides a power supply system that can promptly detect bus short-circuit faults even when a short circuit occurs on the high-voltage DC bus and the short-circuit current is insufficient due to self-protection of each power module, thereby improving the reliability of the power supply system.
[0025] In one embodiment of this application, as Figure 1 As shown, the power system includes a power input circuit 10, a battery unit 20, and a management unit 30. The power input circuit 10 has a first power module 11 and a first protection module 12. One end of the first power module 11 is connected to a power source, and the other end of the first power module 11 is connected to one end of the first protection module 12. The other end of the first protection module 12 is connected to the DC bus 50. The battery unit 20 has a battery module 23, a second power module 21, and a second protection module 22. One end of the second power module 21 is connected to the battery module 23, and the other end of the second power module 21 is connected to one end of the second protection module 22. The other end of the second protection module 22 is connected to the DC bus 50. The first protection module 12 and the second protection module 22 are used to disconnect when the current flowing through them reaches the overcurrent trip threshold. The management unit 30 is connected to the DC bus 50 and is used to control the first protection module 12 to disconnect and the second protection module 22 to disconnect when a first preset short-circuit protection condition is met. The first preset short-circuit protection condition includes that the voltage of the DC bus 50 is within a preset protection voltage range.
[0026] The power system of this application can be any scenario where there is a DC bus 50 and multiple power electronic conversion devices are connected in parallel to supply power, especially high-voltage DC power supply occasions, such as 800V DC power supply systems, data center power supply systems, electric vehicle charging stations or photovoltaic energy storage hybrid systems, etc., and is not specifically limited here.
[0027] The power input circuit 10 can refer to the circuit part that converts external mains power or other forms of primary energy and feeds it to the DC bus 50. It may include a first power module 11 that performs AC / DC or DC / DC conversion and a first protection module 12 that performs switching or isolation functions.
[0028] The battery module 23 in the battery unit 20 refers to an energy storage device for storing and releasing electrical energy. It may include a battery pack or a battery cluster, which is not specifically limited here. The battery module 23 is connected to the DC bus 50 in sequence through the corresponding second power module 21 and second protection module 22, and plays the role of energy regulation and backup power supply.
[0029] The management unit 30 is a unit that receives, processes, and judges information and issues control commands. Its DC bus 50 is connected to establish an information transmission path. The management unit 30 can collect the bus status and execute protection strategies according to preset logical judgment conditions.
[0030] It is understandable that the normal operating state of the first power module 11 and the first protection module 12 is as follows: when a short circuit occurs in any power supply branch on the DC bus 50, the first power module 11 converts the electrical energy from the external power source into DC power and supplies it to the DC bus 50. When the short-circuit current of the branch reaches a threshold, the corresponding first protection module 12 actively trips and disconnects the faulty branch. The normal operating state of the second power module 21 and the second protection module 22 is as follows: when a short circuit occurs in any power supply branch on the DC bus 50, the second power module 21 regulates the charging and discharging process of the battery module 23. When the short-circuit current of the branch reaches a threshold, the corresponding second protection module 22 actively trips and disconnects the faulty branch. Therefore, in the case of a branch overcurrent fault without a busbar short circuit, the first protection module 12 and the second protection module 22 can provide reliable isolation by providing short-circuit capacity and relying on the short-circuit current to reach the overcurrent threshold. However, when a short circuit occurs on the DC bus 50, the current in each branch cannot increase significantly due to the limitations of the normal operating characteristics of the first power module 11 and the second power module 21, such as rapid current limiting. This results in the first protection module 12 and the second protection module 22 being unable to detect an overcurrent sufficient to trigger their operation, thus failing to effectively trip automatically and preventing the short circuit fault on the DC bus 50 from being disconnected in time.
[0031] In this embodiment, at the instant a short-circuit fault occurs on the DC bus 50, due to the inherent overcurrent limiting or tripping protection characteristics of the first power module 11 and the second power module 21, the outputs of the first power module 11 and the second power module 21 will not generate a large current sufficient to drive a conventional circuit breaker. Instead, they will enter a current limiting or protection state, which prevents the first protection module 12 and the second protection module 22 from relying on overcurrent to trigger protection. Simultaneously, the bus short circuit directly causes a sharp drop in the voltage of the DC bus 50. The management unit 30 of this application monitors the voltage of the DC bus 50. When it detects that the voltage of the DC bus 50 has dropped to the preset protection voltage range, the management unit 30 can determine that a special fault, a bus short circuit, has occurred on the DC bus 50. This is because if an overcurrent fault occurs in a branch, the corresponding protection module will trip first due to the large current; however, when the bus is short-circuited, all source-end protection modules cannot detect a current sufficient to trip, and therefore remain in the un-tripped state, thus failing to achieve short-circuit protection and causing serious consequences. This embodiment uses the management unit 30 to detect the bus voltage, identify a fault that traditional protection systems cannot recognize (i.e., a short circuit in the DC bus 50), and forcibly sends a disconnect command to the first protection module 12 and the second protection module 22. Its fundamental purpose is to cut off all paths that inject energy into the bus from the source, thereby effectively avoiding bus short circuit faults, preventing system equipment from being damaged by long-term fault stress, and improving the safety of the power supply system.
[0032] Taking a specific data center high-voltage DC power supply application scenario as an example, multiple AC power sources supply power to the 800V DC bus 50 via the AC / DC power converter 13 (power input circuit 10) and the energy storage battery unit 20 (battery unit 20). When an accidental short circuit occurs on the DC bus 50 due to insulation aging, the potential at that point drops sharply. The management unit 30 detects the voltage drop of the DC bus 50 from 800V to 400V through the voltage acquisition link. This 400V voltage value falls within the preset protection voltage range (e.g., 0V to 600V) set by the system. At this time, the logic judgment unit of the management unit 30 determines that the first preset short-circuit protection condition is met, confirms the occurrence of a bus short-circuit fault, and controls the first protection module 12 and the second protection module 22 to shut down, thus reliably isolating the fault.
[0033] Optionally, if the management unit 30 determines that the first preset short-circuit protection condition is met, it can delay for a certain period of time before shutting down the first protection module 12 and the second protection module 22, thus avoiding erroneous activation of the protection action. The specific delay time is not limited here and depends on the actual application requirements.
[0034] In summary, this power supply system, by communicating with the management unit 30 and the DC bus 50, utilizes the physical characteristic of a sharp voltage drop on the bus when a short circuit occurs to construct an active identification mechanism for short-circuit faults on the DC bus 50. Specifically, when the management unit 30 detects an abnormal voltage drop on the DC bus 50 within a preset protection voltage range, it can identify a bus short-circuit fault that traditional overcurrent protection devices cannot detect. It then controls the first protection module 12 and the second protection module 22 to disconnect, completely cutting off the path of energy injection into the bus at its source, thus achieving active and reliable fault isolation. In this way, this power supply system can still promptly detect bus short-circuit faults even when a short circuit occurs on the high-voltage DC bus 50 and the short-circuit current is insufficient due to self-protection of each power module, thereby improving the reliability of the power supply system.
[0035] In one embodiment, such as Figure 2 As shown, the management unit 30 is also connected to the first power module 11 and the second power module 21 respectively; the management unit 30 is used to control the first protection module 12 and the second protection module 22 to disconnect after a first time period when the first preset short circuit protection condition and the second preset short circuit protection condition are met simultaneously; wherein, the second preset short circuit protection condition includes: the management unit 30 obtains status alarm information issued by the first power module 11 and / or the second power module 21, and the status alarm information includes at least one of output low voltage alarm, output overload alarm or output short circuit alarm.
[0036] Understandably, introducing a second preset short-circuit protection condition increases the dimensions for confirming abnormal states on the power module side. The underlying mechanism is that when a short circuit on the DC bus 50 causes a voltage drop, the source-side converter inevitably triggers its internal control and protection mechanisms in an attempt to maintain output voltage or current, thus issuing a status alarm. This embodiment, through cross-verification of this multi-dimensional information, can further confirm that the voltage drop is not caused by a sudden, large fluctuation in the load, but rather by a fault on the bus side.
[0037] Simultaneously satisfying the first preset short-circuit protection condition and the second preset short-circuit protection condition can mean that the time difference between the moment when the voltage of the DC bus 50 drops to the preset protection voltage range and the moment when the status alarm information is obtained is within a preset time window (e.g., within 50 milliseconds), thereby ensuring that even if there is a small time difference between the two signals arriving at the management unit 30 due to communication delay or device response differences, they can still be accurately associated and identified.
[0038] The logical purpose of the initial delay is to avoid the transient disturbance window caused by brief voltage drops and brief alarms from the power module that may occur during normal transient switching of the load, thereby increasing the reliability of the protection and preventing false protection. As a feasible implementation, the initial delay can be greater than the self-filtering response time of the power module's internal control loop to ensure the filtering out of transient communication jitter or loop regulation fluctuations. Simultaneously, the initial delay can be less than the short-circuit thermal stability withstand limit time of key semiconductor devices and passive components (such as the DC bus 50 capacitor and the power module) in the system to ensure that the protection module disconnects before irreversible thermal damage occurs.
[0039] Optionally, the duration of the first duration can be set to hundreds of milliseconds or even several seconds, without any specific limitation here.
[0040] In one embodiment, the management unit 30 is used to control the first protection module 12 and the second protection module 22 to disconnect after a second delay when both the first preset short-circuit protection condition and the third preset short-circuit protection condition are met simultaneously; wherein, the third preset short-circuit protection condition includes: the management unit 30 obtains insulation fault alarm information of the DC bus 50.
[0041] It is understandable that a bus short circuit may be accompanied by or worsen into an insulation failure to ground. An insulation failure is a more serious and dangerous fault mode, potentially causing secondary disasters such as electric shock and fire. Therefore, when the management unit 30 detects a voltage drop on the DC bus 50 and all protection modules remain active, and simultaneously receives an insulation failure alarm, it executes the protection action after a second delay. This graded protection strategy, which implements different delay gradients based on the accompanying characteristics of the fault (whether or not an insulation alarm is present), improves the protection response speed of the power system under extreme fault conditions, thereby enhancing safety and reliability. As a specific implementation method, the insulation failure alarm information originates from devices such as synchronous injection insulation monitoring devices.
[0042] As a specific implementation method, the insulation fault alarm information originates from the insulation monitoring device installed on the DC bus 50. The insulation monitoring device can monitor the insulation resistance of the positive and negative poles of the DC bus 50 to ground in real time through methods such as the balanced bridge method and the low-frequency signal injection method (such as the synchronous injection insulation monitoring device). When the insulation resistance is lower than the preset insulation threshold (for example, lower than the electric shock safety threshold of 50Ω / V or 100Ω / V), the insulation monitoring device sends an insulation fault alarm signal to the management unit 30 through the communication bus (such as the CAN bus) or the hard-wired GPIO port.
[0043] To prevent false protection caused by accumulated insulation alarms or transient noise interference, and to simultaneously meet the first and third preset short-circuit protection conditions, the following conditions can be met: The moment when the management unit 30 obtains the DC bus 50 voltage drop to the preset protection voltage range and the moment it obtains the insulation fault alarm signal are within the same preset time window (e.g., within 100 milliseconds); or, the moment the insulation fault alarm signal is generated lags behind the moment the bus voltage drops, and the lag time is within a preset time difference limit. This ensures that the insulation fault is indeed induced by the current bus short circuit or short-circuit arc igniting the ground medium, thus improving reliability.
[0044] The second duration can be set to a value between tens of milliseconds (e.g., 10 to 50 milliseconds). The lower limit of the second duration should be greater than the signal sampling and analog-to-digital conversion cycle of the management unit 30 (e.g., greater than 5 milliseconds) to ensure accurate signal identification. Optionally, the second duration may be less than the human body's safe electric shock tolerance limit or the minimum time for an arc discharge to ignite the insulating casing of electrical equipment, thereby minimizing the risk of electric shock and secondary fires in emergency situations of insulation failure.
[0045] In one embodiment, such as Figure 3 As shown, the management unit 30 is also connected to the first protection module 12 and the second protection module 22; the management unit 30 is used to control the first protection module 12 and the second protection module 22 to disconnect after a third time period when the first preset short circuit protection condition and the fourth preset short circuit protection condition are met simultaneously; the fourth preset short circuit protection condition includes the first protection module 12 and the second protection module 22 being in an undisconnected state.
[0046] The management unit 30 acquires the on / off status of the first protection module 12 and the second protection module 22 in real time through their respective auxiliary contact acquisition links or status feedback interfaces. When a short circuit occurs on the DC bus 50, the bus voltage drops to a preset voltage range, satisfying the first preset short-circuit protection condition. At the same time, since each power converter 13 and each voltage converter 24 has overcurrent limiting or self-protection characteristics, the short-circuit current is limited to a safe range, causing neither the first protection module 12 nor the second protection module 22 to reach the physical overcurrent trip threshold, thus both remain in a closed on / off state (i.e., not open state), satisfying the fourth preset short-circuit protection condition.
[0047] When the management unit 30 determines that both the first and fourth preset short-circuit protection conditions are met simultaneously, if, within the third time period, the bus voltage momentarily drops and recovers to the normal operating voltage range due to transient conditions such as large-capacity capacitor surges or high-power motor startup on the load side, or if any protection module has automatically tripped, the management unit 30 resets the third time period timer and does not output a disconnection command, thereby avoiding false tripping of the system caused by transient voltage fluctuations. If, at the end of the third time period, the DC bus 50 voltage is still within the preset voltage range, and the first protection module 12 and the second protection module 22 are not disconnected, then a short circuit is determined in the DC bus 50, and the management unit 30 controls the first protection module 12 and the second protection module 22 to disconnect.
[0048] Optionally, the duration of the third duration can be set to hundreds of milliseconds or even several seconds, without being limited here.
[0049] In one embodiment, the management unit is configured to control the first protection module and the second protection module to be directly disconnected when the first preset short-circuit protection condition, the second preset short-circuit protection condition, the third preset short-circuit protection condition, and the fourth preset short-circuit protection condition are simultaneously met; wherein, the second preset short-circuit protection condition includes: the management unit obtaining status alarm information issued by the first power module and / or the second power module, the status alarm information including at least one of output low voltage alarm, output overload alarm, or output short-circuit alarm; the third preset short-circuit protection condition includes: the management unit obtaining insulation fault alarm information of the DC bus; the fourth preset short-circuit protection condition includes that both the first protection module and the second protection module are in an undisconnected state.
[0050] When all four preset short-circuit protection conditions—the first, second, third, and fourth—are met, a strong chain of evidence is formed confirming a short circuit in the busbar with insulation degradation, corroborated by the power module's own behavior. Thus, the short-circuit fault in DC bus 50 is definitively confirmed. The management unit 30 can then directly control the first protection module 12 and the second protection module 22 to disconnect without any functional delay, ensuring system and personnel safety as quickly as possible.
[0051] To ensure the spatiotemporal consistency of the aforementioned four-dimensional anomaly information and avoid misjudgments due to differences in acquisition and transmission delays from different signal sources, the first, second, and third preset short-circuit protection conditions must be met simultaneously. This means that within the current software control cycle (or a preset judgment time window, such as 50 milliseconds), the management unit 30 simultaneously detects that the voltage of the DC bus 50 is within the preset protection voltage range, all first protection modules 12 and second protection modules 22 are in a closed, non-operational state, receives status alarm information from the first power module 11 and / or the second power module 21, and receives insulation fault alarm information from the DC bus 50. Thus, by coupling and verifying the aforementioned bus voltage, protection device status, power module alarms, and insulation degradation alarms, interference from transient switching of high-power loads, single-point sensor failures, or occasional communication noise on the protection system is eliminated.
[0052] It should be noted that, under the condition that only the first preset short-circuit protection condition is met, the delay duration for the management unit 30 to control the disconnection of the first protection module 12 and the second protection module 22 is the fifth duration. For example, the order of the first, second, third, and fifth durations is as follows: the second duration is less than the first duration, the first duration is less than the third duration, and the fifth duration is greater than the third duration. This setting allows for debouncing and filtering via the fifth duration when relying solely on the single criterion of DC bus 50 voltage drop, preventing malfunctions caused by transient fluctuations. Furthermore, when multiple fault characteristics such as power module alarms or insulation alarms are simultaneously acquired, the response delay is shortened accordingly, enabling rapid isolation of high-risk deterministic short-circuit faults.
[0053] In one embodiment, the first preset short-circuit protection condition is a fundamental necessary condition, while the second, third, and fourth preset short-circuit protection conditions serve as auxiliary filtering conditions to filter transient voltage fluctuations, load surges, or transient interference generated by the connection of large-capacity capacitors during system operation. It is understood that, in addition to the first preset short-circuit protection condition being combined with any one or all of the second, third, and fourth preset short-circuit protection conditions, in practical applications, the first preset short-circuit protection condition can also be combined with any two of the second, third, and fourth preset short-circuit protection conditions to balance the requirements for preventing malfunctions and response speed under different operating conditions. Of course, the delay duration in different situations can depend on the actual application requirements, and the specific duration is not limited here. It is understood that the more conditions are met, the shorter the delay duration can be.
[0054] In one embodiment, such as Figure 4As shown, the first power module 11 includes multiple power converters 13, the first protection module 12 includes multiple first switching devices 14, the multiple power converters 13 are connected one-to-one with the multiple first switching devices 14, the multiple power converters 13 are used to connect to the power supply, and the first switching devices 14 are connected to the DC bus 50.
[0055] In this embodiment, the input terminals of each power converter 13 are connected to their respective external input power supplies, and the output terminals of each power converter 13 are connected to the input terminals of their respective first switching devices 14. The output terminals of each first switching device 14 are all connected to the DC bus 50. In this topology, the input branches formed by the power converters 13 are connected in parallel. When a single-point hardware failure occurs in any input branch, the management unit 30 controls the single first switching device 14 corresponding to that branch to disconnect, thereby isolating the faulty branch, while the remaining input branches that have not experienced a failure maintain normal power supply.
[0056] Alternatively, the power converter 13 may be an AC-DC converter (AC / DC rectifier system) or a solid-state transformer (SST).
[0057] In one embodiment, such as Figure 4 As shown, the second power module 21 includes multiple voltage converters 24, the second protection module 22 includes multiple second switching devices 26, and the battery module 23 includes multiple battery devices 25. The multiple battery devices 25, the multiple voltage converters 24, and the multiple second switching devices 26 are connected in series one-to-one. Each battery device 25 is connected to one end of the corresponding voltage converter 24, the other end of the voltage converter 24 is connected to one end of the corresponding second switching device 26, and the other end of the second switching device 26 is connected to the DC bus 50.
[0058] In the parallel branches on the battery side, each battery branch consists of a battery device 25, a voltage converter 24, and a second switching device 26 connected in series. The output terminal of the battery device 25 is connected to the input terminal of the corresponding voltage converter 24, and the output terminal of the voltage converter 24 is connected to the input terminal of the corresponding second switching device 26. The output terminals of each second switching device 26 are connected to the DC bus 50. In this topology, each voltage converter 24 can independently control the charging and discharging of its corresponding battery device 25; when the management unit 30 controls all the second switching devices 26 to be disconnected simultaneously, each battery device 25 is isolated from the others in the disconnected state.
[0059] Optionally, the voltage converter 24 can be a DC / DC conversion system. The battery device 25 can include a battery pack or battery cluster, or it can include a battery management unit 30 and related control circuitry; the specifics are not limited here.
[0060] In one embodiment, the management unit 30 is connected to multiple power converters 13, multiple voltage converters 24, multiple first switching devices 14, and multiple second switching devices 26, respectively. The management unit 30 is used to control all first switching devices 14 and all second switching devices 26 to disconnect after a fourth time delay when a first preset short-circuit protection condition, a second preset short-circuit protection condition, and a fourth preset short-circuit protection condition are simultaneously met. The second preset short-circuit protection condition specifically includes: the management unit 30 obtains status alarm information issued by at least one power converter 13, and / or, the management unit 30 obtains status alarm information issued by at least one voltage converter 24. The fourth preset short-circuit protection condition specifically includes: all first switching devices 14 and all second switching devices 26 are in an undisconnected state.
[0061] In the above-mentioned system topology of multiple modules in parallel, the management unit 30 continuously monitors the potential of the DC bus 50 through sensors, and obtains the auxiliary contact status of each first switching device 14 and each second switching device 26 through the signal acquisition link. At the same time, it reads the operating status information of each power converter 13 and each voltage converter 24 in real time through the communication interface.
[0062] When a short circuit occurs on the DC bus 50, the bus potential drops to within the preset protection voltage range, thus satisfying the first preset short-circuit protection condition. Since each power converter 13 and each voltage converter 24 has built-in overcurrent limiting or self-protection logic, the short-circuit current is limited, ensuring that all first switching devices 14 and all second switching devices 26 remain closed without reaching the physical trip threshold, thus satisfying the fourth preset short-circuit protection condition. At least one power converter 13 or at least one voltage converter 24 triggers an internal alarm due to output overcurrent limiting and sends an output low-voltage alarm, output overload alarm, or output short-circuit alarm to the management unit 30, thus satisfying the second preset short-circuit protection condition. When all the above conditions are simultaneously satisfied, the management unit 30 determines that a short-circuit fault has occurred on the DC bus 50 and, after a fourth time interval, synchronously outputs a disconnect command to all first switching devices 14 and all second switching devices 26 via a hardware interrupt or a dedicated hardwired path, cutting off all energy sources supplying the DC bus 50.
[0063] In one feasible implementation, the management unit 30 acquires the operating status of each power converter 13 and each voltage converter 24 in real time through their respective communication interfaces. When a short circuit occurs on the DC bus 50, the bus voltage drops to the preset protection voltage range, satisfying the first preset short-circuit protection condition; simultaneously, all first switching devices 14 and all second switching devices 26 remain closed (i.e., not open), satisfying the fourth preset short-circuit protection condition; and at least one power converter 13 and / or at least one voltage converter 24 reports a status alarm to the management unit 30 due to limiting the output short-circuit current, satisfying the second preset short-circuit protection condition. After determining that the first, second, and fourth preset short-circuit protection conditions are simultaneously satisfied, the management unit 30 starts the fourth duration timer. If, within the fourth time period, any power converter 13 or any voltage converter 24 cancels its status alarm information due to the disappearance of interference caused by transient load switching, or the voltage of the DC bus 50 returns to the normal operating voltage range, or any first switching device 14 or second switching device 26 disconnects automatically, then the management unit 30 resets the fourth time period timer and does not output a disconnect command; if the above conditions are still met when the fourth time period expires, then the management unit 30 synchronously outputs a disconnect command to all first switching devices 14 and all second switching devices 26.
[0064] In one feasible embodiment, an insulation monitoring device is also connected in parallel to the DC bus 50, and the signal output terminal of the insulation monitoring device is connected to the management unit 30. When a short circuit occurs in the DC bus 50 and an insulation fault to ground occurs, the bus voltage drops to the preset protection voltage range (meeting the first preset short circuit protection condition), and at the same time, the insulation monitoring device sends an insulation fault alarm message to the management unit 30 (meeting the third preset short circuit protection condition). Since the insulation fault involves personal safety and equipment fire risk, the management unit 30 starts a second timer when both the first and third preset short circuit protection conditions are met. When the second time expires, the management unit 30 directly outputs a disconnect command to all first switching devices 14 and all second switching devices 26 through the multi-way trip control link, forcibly disconnecting all external power converter 13 branches and all battery unit 20 branches, realizing accelerated tripping under high-risk fault conditions.
[0065] In one feasible implementation, within the same microprocessor control cycle, the management unit 30 simultaneously satisfies the following four preset short-circuit protection conditions: a first preset short-circuit protection condition (DC bus 50 voltage is within a preset protection voltage range), a second preset short-circuit protection condition (at least one power converter 13 or voltage converter 24 issues a status alarm message), a third preset short-circuit protection condition (the insulation monitoring device issues an insulation fault alarm message), and a fourth preset short-circuit protection condition (all first switching devices 14 and all second switching devices 26 are in an undisconnected state). At this time, the multi-dimensional fault characteristics are aligned on the time axis, forming a deterministic chain of evidence for a bus short circuit and insulation failure. The management unit 30 does not perform any debouncing delay at the software algorithm level, directly and synchronously sending disconnect commands to all first switching devices 14 and all second switching devices 26 to achieve direct shutdown protection.
[0066] It is understood that the above are only some combinations of the first preset short-circuit protection condition and the second to fourth preset short-circuit protection conditions. The principle of other combinations is the same, and they will not be described in detail here.
[0067] In one embodiment, such as Figure 4 As shown, the power supply system also includes a power output circuit 40. The input terminal of the power output circuit 40 is connected to the DC bus 50, and the output terminal of the power output circuit 40 is used to connect to the target load. The power output circuit 40 includes a DC-DC converter or a DC-AC converter. It is evident that the DC bus 50 is used to construct an intermediate energy pool, and the output circuit can be flexibly selected at the back end according to the characteristics of the final load, greatly improving the adaptability of the power supply system to various complex loads.
[0068] In one embodiment, the minimum value of the preset protection voltage range of the DC bus 50 is greater than or equal to 0V, and the maximum value of the preset protection voltage range is less than or equal to the minimum operating voltage of the target load.
[0069] Regarding voltage specifications, let's take a target load with a minimum operating voltage of 800V DC as an example: The rated operating voltage of DC bus 50 is 800V. The minimum value of the preset protection voltage range is greater than or equal to 0V, and the preset protection voltage range should ensure the load can operate continuously, such as being less than or equal to 600V. This parameter range needs to be adapted to the operating voltage range of the end load equipment. If the minimum input voltage range of the end equipment is 600V, when the 800V rated bus drops below 600V, it has deviated from the normal operating voltage window, which is sufficient to indicate that an abnormal low impedance path to ground or severe power mismatch has occurred. For end loads with a wide input voltage range, or when the load power supply is derated even if the input voltage decreases, but the load can still operate normally, this voltage can be adjusted according to the actual situation.
[0070] Optionally, the maximum value of the preset protection voltage range can be 75%-85% of the minimum operating voltage of the target load, and the specific value is not limited here.
[0071] In some optional implementations, the threshold value for the preset protection voltage range is not fixed as a single static value, but can be dynamically adjusted according to the actual operating point of the DC bus 50 during normal operation. For example, when the system is in partial power standby or operating in energy-saving mode, the bus voltage will fluctuate significantly between 800V and 750V. At this time, the management unit 30 can dynamically adjust the voltage threshold value for triggering the bus short-circuit criterion to a floating value that follows the operating mode, so that the voltage drop criterion of this scheme has accurate adaptability to different operating conditions, further avoiding false triggering within the voltage fluctuation range.
[0072] In some alternative implementations, to further prevent a sudden voltage drop caused by the sudden connection of a large-capacity capacitor or the starting of a large motor on the load side, which could trigger a transient current limiting alarm in the power module, the management unit 30 also integrates a logic blocking criterion for the rate of change of voltage (dv / dt). When the voltage drops rapidly but dv / dt is higher than a certain set threshold, and there is no insulation alarm during this process, it can be determined that it is a load surge rather than a bus short circuit. This allows the current protection action to be disabled, and the system to wait for the voltage to recover. This solves the problem of difficulty in distinguishing between load startup and bus short circuit faults caused by a sudden high-power surge.
[0073] Regarding the specific implementation of the management unit 30, it is not limited to a single physical entity; it can be a control device with a microcontroller (MCU), field-programmable gate array (FPGA), or complex programmable logic device (CPLD) as the core logic processing unit. This control device has a voltage sampling and conditioning circuit for coupling the DC bus 50 voltage, and multiple digital I / O interfaces or communication buses for receiving the on / off status of the first protection module 12 and the second protection module 22, as well as acquiring status alarm information from the first power module 11 and the second power module 21. Information acquisition can be achieved through a hard-wired interface or through fieldbuses such as Controller Area Network (CAN) or RS485. Regarding the protection modules, the first protection module 12 or the second protection module 22 can be a high-capacity DC circuit breaker with an electric operating mechanism or shunt trip accessory, or it can be a smart fuse with remote shut-off function or a series combination of a high-power contactor and a fuse, as long as it has the ability to receive external commands and physically disconnect the circuit.
[0074] It is understood that the power supply system provided in this application can be applied to electronic devices, including power-consuming devices, whose power input terminals are connected to the output terminals of the power supply system. These power-consuming devices can be data center cabinets, electric vehicle charging terminals, or industrial inverter loads, etc. By combining the power supply system with high-reliability bus protection capabilities provided in this application with specific power-consuming devices, a highly robust integrated power supply device can be constructed that can accurately identify and reliably protect against internal bus faults under any load-side disturbance.
[0075] The electrical device can be used as a target load and connected to the output terminal of the power supply system (output terminal of the power output circuit 40).
[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no technical conflict, the various technical features mentioned in the various embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A power supply system, characterized in that, The power supply system includes: A power input circuit, the power input circuit having a first power module and a first protection module, one end of the first power module being used to connect to a power source, the other end of the first power module being connected to one end of the first protection module, and the other end of the first protection module being connected to a DC bus. A battery unit, comprising a battery module, a second power module, and a second protection module, wherein one end of the second power module is connected to the battery module, the other end of the second power module is connected to one end of the second protection module, and the other end of the second protection module is connected to a DC bus. The first protection module and the second protection module are used to disconnect when the current flowing through them reaches the overcurrent trip threshold; A management unit is connected to the DC bus. The management unit is used to control the first protection module and the second protection module to disconnect when a first preset short-circuit protection condition is met. The first preset short-circuit protection condition includes: the voltage of the DC bus is within a preset protection voltage range.
2. The power supply system as described in claim 1, characterized in that, The management unit is also connected to the first power module and the second power module respectively; The management unit is used to control the first protection module and the second protection module to disconnect after a first time period when the first preset short circuit protection condition and the second preset short circuit protection condition are simultaneously met. The second preset short-circuit protection condition includes: the management unit obtains status alarm information issued by the first power module and / or the second power module, and the status alarm information includes at least one of output low voltage alarm, output overload alarm or output short circuit alarm.
3. The power supply system as described in claim 1, characterized in that, The management unit is used to control the first protection module and the second protection module to disconnect after a second delay when both the first preset short-circuit protection condition and the third preset short-circuit protection condition are met simultaneously. The third preset short-circuit protection condition includes: the management unit obtaining insulation fault alarm information of the DC bus.
4. The power supply system as described in claim 1, characterized in that, The management unit is also connected to the first protection module and the second protection module; The management unit is used to control the first protection module and the second protection module to disconnect after a third time period when both the first preset short-circuit protection condition and the fourth preset short-circuit protection condition are met simultaneously. The fourth preset short-circuit protection condition includes the first protection module and the second protection module being in an undisconnected state.
5. The power supply system as described in claim 1, characterized in that, The management unit is used to control the first protection module and the second protection module to disconnect directly when the first preset short circuit protection condition, the second preset short circuit protection condition, the third preset short circuit protection condition and the fourth preset short circuit protection condition are met simultaneously. The second preset short-circuit protection condition includes: the management unit obtains status alarm information issued by the first power module and / or the second power module, the status alarm information including at least one of output low voltage alarm, output overload alarm or output short circuit alarm; The third preset short-circuit protection condition includes: the management unit obtaining insulation fault alarm information of the DC bus; The fourth preset short-circuit protection condition includes the fact that both the first protection module and the second protection module are in an undisconnected state.
6. The power supply system as described in claim 1, characterized in that, The first power module includes multiple power converters, the first protection module includes multiple first switching devices, the multiple power converters are connected one-to-one with the multiple first switching devices, the multiple power converters are used to connect to a power source, and the first switching devices are connected to the DC bus.
7. The power supply system as described in claim 6, characterized in that, The second power module includes multiple voltage converters, the second protection module includes multiple second switching devices, and the battery module includes multiple battery devices. Multiple battery devices, multiple voltage converters, and multiple second switching devices are connected in series one-to-one, wherein each battery device is connected to one end of the corresponding voltage converter, the other end of the voltage converter is connected to one end of the corresponding second switching device, and the other end of the second switching device is connected to the DC bus.
8. The power supply system as described in claim 7, characterized in that, The management unit is connected to multiple power converters, multiple voltage converters, multiple first switching devices, and multiple second switching devices respectively. The management unit is used to control all the first switching devices and all the second switching devices to disconnect after a delay of a fourth time when the first preset short circuit protection condition, the second preset short circuit protection condition, and the fourth preset short circuit protection condition are simultaneously met. The second preset short-circuit protection condition specifically includes: the management unit obtaining status alarm information issued by at least one of the power converters, and / or the management unit obtaining status alarm information issued by at least one of the voltage converters; The fourth preset short-circuit protection condition specifically includes: all the first switching devices and all the second switching devices are in an undisconnected state.
9. The power supply system according to any one of claims 1 to 8, characterized in that, The power system also includes a power output circuit, the input terminal of which is connected to the DC bus, and the output terminal of which is used to connect to the target load. The power output circuit includes a DC-DC converter or a DC-AC converter.
10. The power supply system according to any one of claims 1 to 8, characterized in that, The minimum value of the preset protection voltage range of the DC bus is greater than or equal to 0V, and the maximum value of the preset protection voltage range is less than or equal to the minimum operating voltage of the target load.