DC power supply system, control method and power supply equipment

Abstract

The invention provides a direct-current power supply system, a control method and power supply equipment, and belongs to the technical field of power supplies. The direct-current power supply system comprises a direct-current bus, at least two battery packs and at least two bidirectional direct-current conversion modules, the battery packs are in one-to-one correspondence with the bidirectional DC conversion modules; the bidirectional DC conversion module is an isolated bidirectional DC conversion module; the first positive connection end of the bidirectional DC conversion module is connected with the DC bus, the first negative connection end of the bidirectional DC conversion module is connected with the positive electrode of the corresponding battery pack, and the second positive connection end of the bidirectional DC conversion module is connected with the positive electrode of the corresponding battery pack. The second negative connection end of the bidirectional DC conversion module is connected with the negative electrode of the corresponding battery pack. Energy exchange between the battery packs and the direct-current bus and energy exchange between the battery packs can only be carried out through the bidirectional direct-current conversion module, direct current exchange between the battery packs cannot be generated, and therefore the circumstances of circulating current and mutual charging and discharging between the battery packs can be avoided.

Description

Technical Field

[0001] The present invention relates to the field of power supply technology, and in particular to a direct current power supply system, a control method and a power supply device. Background Art

[0002] The main function of the DC power supply system is to supply power to various load devices through the DC bus. When the AC grid is normal, the AC grid converts the power into DC power to supply the DC bus. When the AC grid fails and cannot supply power, the battery pack discharges to supply power to the DC bus.

[0003] In the related art, multiple battery packs are usually connected to the DC bus. When the AC power grid is normal, the DC bus can normally power various load devices and charge various battery packs; when the AC power grid is abnormal, each battery pack discharges to power the DC bus. However, in the existing architecture, there are problems of circulating current and mutual charging and discharging between various battery packs. Summary of the invention

[0004] The embodiments of the present invention provide a direct current power supply system, a control method and a power supply device to solve the problems of circulating current and mutual charging and discharging between battery packs in the existing direct current power supply system.

[0005] In a first aspect, an embodiment of the present invention provides a DC power supply system, including a DC bus, at least two battery packs and at least two bidirectional DC conversion modules; the battery packs and the bidirectional DC conversion modules correspond one to one; the bidirectional DC conversion modules are isolated bidirectional DC conversion modules;

[0006] The first positive connection end of the bidirectional DC conversion module is connected to the DC bus, the first negative connection end of the bidirectional DC conversion module is connected to the positive pole of the corresponding battery pack, the second positive connection end of the bidirectional DC conversion module is connected to the positive pole of the corresponding battery pack, and the second negative connection end of the bidirectional DC conversion module is connected to the negative pole of the corresponding battery pack.

[0007] In a possible implementation, when the battery pack is in a charging state, the DC bus charges the battery pack through a first negative connection terminal of a bidirectional DC conversion module corresponding to the battery pack and a second positive connection terminal of the bidirectional DC conversion module corresponding to the battery pack.

[0008] In one possible implementation, when the battery pack is in a discharging state, if the bidirectional DC conversion module corresponding to the battery pack is in a normal state, the battery pack supplies power to the DC bus through the first positive connection terminal of the corresponding bidirectional DC conversion module and the second negative connection terminal of the corresponding bidirectional DC conversion module.

[0009] In a possible implementation, when the battery pack is in a discharging state, if the bidirectional DC conversion module corresponding to the battery pack is in a failed state, the battery pack supplies power to the DC bus through the body diode of the corresponding bidirectional DC conversion module.

[0010] In a possible implementation, the bidirectional DC conversion module is a high-frequency transformer electrically isolated bidirectional DC conversion module.

[0011] In a possible implementation, the DC power supply system further includes an AC-DC conversion module;

[0012] The AC end of the AC / DC conversion module is used to connect to an AC power source, the first DC end of the AC / DC conversion module is connected to a DC bus, and the second DC end of the AC / DC conversion module is connected to the negative pole of the battery pack.

[0013] In a possible implementation, the AC-DC conversion module includes at least two AC-DC conversion units connected in parallel.

[0014] In a second aspect, an embodiment of the present invention provides a control method for controlling a DC power supply system as described in the first aspect or any possible implementation of the first aspect; the control method includes:

[0015] When the battery pack is in a charging state, the bidirectional DC conversion module corresponding to the battery pack is controlled so that the DC bus charges the battery pack through the first negative connection terminal of the bidirectional DC conversion module corresponding to the battery pack and the second positive connection terminal of the bidirectional DC conversion module corresponding to the battery pack.

[0016] In a possible implementation, the control method further includes:

[0017] Monitor the status of the bidirectional DC conversion module;

[0018] When the battery pack is in a discharging state, if the bidirectional DC conversion module corresponding to the battery pack is in a normal state, the bidirectional DC conversion module corresponding to the battery pack is controlled so that the battery pack supplies power to the DC bus through the first positive connection terminal of the corresponding bidirectional DC conversion module and the second negative connection terminal of the corresponding bidirectional DC conversion module; if the bidirectional DC conversion module corresponding to the battery pack is in a failure state, the battery pack is controlled to supply power to the DC bus through the body diode of the corresponding bidirectional DC conversion module.

[0019] In a third aspect, an embodiment of the present invention provides a power supply device, comprising a DC power supply system as described in the first aspect or any possible implementation of the first aspect.

[0020] The embodiment of the present invention provides a direct current power supply system, a control method and a power supply device. The direct current power supply system includes a direct current bus, at least two battery packs and at least two bidirectional direct current conversion modules; the battery packs and the bidirectional direct current conversion modules correspond to each other one by one; the bidirectional direct current conversion modules are isolated bidirectional direct current conversion modules; the first positive connection end of the bidirectional direct current conversion module is connected to the direct current bus, the first negative connection end of the bidirectional direct current conversion module is connected to the positive pole of the corresponding battery pack, the second positive connection end of the bidirectional direct current conversion module is connected to the positive pole of the corresponding battery pack, and the second negative connection end of the bidirectional direct current conversion module is connected to the negative pole of the corresponding battery pack; each battery pack in the direct current power supply system is connected to a bidirectional direct current conversion module, and the bidirectional direct current conversion module is an isolated bidirectional direct current conversion module, and the energy exchange between the battery pack and the direct current bus and between each battery pack can only be performed through the bidirectional direct current conversion module, and no direct current exchange between the battery packs will be generated, thereby avoiding the occurrence of circulation and mutual charging and discharging between the battery packs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 is a schematic structural diagram of a DC power supply system provided by an embodiment of the present invention;

[0023] Figure 2 It is a structural schematic diagram of a bidirectional DC conversion module provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0026] See also Figure 1The DC power supply system provided in the embodiment of the present application includes a DC bus 11, at least two battery packs 12 and at least two bidirectional DC conversion modules 13; the battery packs 12 and the bidirectional DC conversion modules 13 correspond to each other one by one; the bidirectional DC conversion module 13 is an isolated bidirectional DC conversion module;

[0027] The first positive connection end of the bidirectional DC conversion module 13 is connected to the DC bus 11, the first negative connection end of the bidirectional DC conversion module 13 is connected to the positive pole of the corresponding battery pack 12, the second positive connection end of the bidirectional DC conversion module 13 is connected to the positive pole of the corresponding battery pack 12, and the second negative connection end of the bidirectional DC conversion module 13 is connected to the negative pole of the corresponding battery pack 12.

[0028] Among them, the bidirectional DC conversion module 13 is a bidirectional DC-DC module, which is an isolated topology structure, that is, the bidirectional DC conversion module 13 is an isolated bidirectional DC conversion module, which can be specifically a high-frequency transformer electrically isolated topology, that is, the bidirectional DC conversion module 13 is a high-frequency transformer electrically isolated bidirectional DC conversion module.

[0029] For example, the structure of the bidirectional DC conversion module 13 is as follows: Figure 2 As shown, it includes a first switch tube S1, a second switch tube S2, a third switch tube S3, a fourth switch tube S4, a fifth switch tube S5, a sixth switch tube S6, a seventh switch tube S7, an eighth switch tube S8, a first resonant capacitor C r1 , the first resonant inductor L r1 , Excitation inductance L m , the second resonant inductor L r2 , the second resonant capacitor C r2 And transformer. The connection relationship between each device can be found in Figure 2 The transformation ratio of the transformer may be n:1.

[0030] Figure 2 The “+” connection terminal on the power supply side of the bidirectional DC conversion module 13 is the first positive connection terminal of the bidirectional DC conversion module 13, which is connected to the DC bus 11; Figure 2 The “-” connection terminal on the power supply side of the bidirectional DC conversion module 13 is the first negative connection terminal of the bidirectional DC conversion module 13, which is connected to the positive electrode of the corresponding battery pack 12; Figure 2 The “+” connection terminal on the battery side of the bidirectional DC conversion module 13 is the second positive connection terminal of the bidirectional DC conversion module 13, which is connected to the positive electrode of the corresponding battery pack 12; Figure 2 The “−” connection terminal on the battery side of the bidirectional DC conversion module 13 is the second negative connection terminal of the bidirectional DC conversion module 13 , which is connected to the negative electrode of the corresponding battery pack 12 .

[0031] It should be noted that Figure 2 The structure of the bidirectional DC conversion module 13 shown is only one structural example of the bidirectional DC conversion module 13. The structure of the bidirectional DC conversion module 13 described in the present application is not limited to Figure 2 The structure shown, and the structure of any isolated bidirectional DC conversion module are within the protection scope of this application.

[0032] The primary and secondary of the bidirectional DC conversion module 13 both have controllable switch elements (for example, Figure 2 The first switch tube to the eighth switch tube shown in the figure can realize controllable current and voltage, and realize high-efficiency and bidirectional transmission of power through phase angle control at multiple angles. At the same time, the priority bus (selecting one direction of the power supply side or the battery side as priority) power supply control strategy can be set to realize priority power supply of the bus under any circumstances.

[0033] The battery pack 12 may include multiple batteries, and the multiple batteries may be connected in series or in parallel, or partially in parallel and then in series with other batteries, or partially in series and then in parallel with other batteries, etc., without specific limitation here.

[0034] The DC power supply system provided in the embodiment of the present application includes a DC bus 11, at least two battery packs 12 and at least two bidirectional DC conversion modules 13; the battery packs 12 and the bidirectional DC conversion modules 13 correspond to each other one by one; the bidirectional DC conversion module 13 is an isolated bidirectional DC conversion module; the first positive connection end of the bidirectional DC conversion module 13 is connected to the DC bus 11, the first negative connection end of the bidirectional DC conversion module 13 is connected to the positive electrode of the corresponding battery pack 12, the second positive connection end of the bidirectional DC conversion module 13 is connected to the positive electrode of the corresponding battery pack 12, and the bidirectional DC conversion module 13 The second negative connection end is connected to the negative electrode of the corresponding battery pack 12; each battery pack 12 in the DC power supply system is connected to a bidirectional DC conversion module 13, and the bidirectional DC conversion module 13 is an isolated bidirectional DC conversion module. The energy exchange between the battery pack 12 and the DC bus 11 and between each battery pack 12 can only be carried out through the bidirectional DC conversion module 13, and no direct current exchange will be generated between the battery packs 12, thereby avoiding the circulation and mutual charging and discharging between the battery packs 12, avoiding affecting the life of the battery pack 12 and damaging the battery pack 12.

[0035] In addition, the first negative connection terminal and the second positive connection terminal of the bidirectional DC conversion module 13 in the embodiment of the present application are both connected to the positive pole of the corresponding battery group 12. Compared with the related art in which only the second positive connection terminal of the bidirectional DC conversion module 13 is connected to the positive pole of the battery group 12, the charging and discharging efficiency of the battery group 12 can be significantly improved.

[0036] In the embodiment of the present application, a bidirectional DC conversion module 13 manages a battery pack 12, and each battery pack 12 can use batteries of different capacities and different manufacturers, and can realize free combination between battery packs 12. In addition, the system can use battery packs 12 of any ampere-hour, and multiple battery packs 12 connected in parallel can meet large capacity requirements, while limiting and reducing the power level of the power conversion module, which can effectively reduce costs.

[0037] The DC power supply system adopts a distributed tree topology (i.e., multiple bidirectional DC conversion modules 13 are connected in parallel on the DC bus 11), which can quickly isolate faults and improve the flexibility of networking, effectively improving system reliability. In addition, a variety of control strategies can be used in the system to keep the system in a stable state at all times. When problems occur at some nodes, the problem nodes can also be quickly isolated adaptively.

[0038] In some possible implementations, a blocking diode is provided between the DC bus 11 and each battery pack 12 .

[0039] In the embodiment of the present application, each battery pack 12 is connected to a bidirectional DC conversion module 13. Since the bidirectional DC conversion module 13 is an electrically isolated topology by a high-frequency transformer, a check diode is arranged between the battery pack 12 and the DC bus 11. The energy exchange between the battery pack 12 and the DC bus 11 and other battery packs 12 can only be achieved through the electrical isolation circuit of the bidirectional DC conversion module 13 to control the voltage and current, and there will be no "direct" current exchange problem between the battery packs 12, thereby avoiding the problem of circulation and mutual charging and discharging between the battery packs 12.

[0040] In some embodiments, when the battery pack 12 is in a charging state, the DC bus 11 charges the battery pack 12 through the first negative connection end of the bidirectional DC conversion module 13 corresponding to the battery pack 12 and the second positive connection end of the bidirectional DC conversion module 13 corresponding to the battery pack 12.

[0041] In this embodiment, when any battery pack 12 is in a charging state, the current flowing out of the DC bus 11 flows into the bidirectional DC conversion module 13 through the first positive connection end of the bidirectional DC conversion module 13 corresponding to the battery pack 12, and the current flowing out of the first negative connection end of the bidirectional DC conversion module 13 and the second positive connection end of the bidirectional DC conversion module 13 are both used to charge the battery pack 12, that is, the two currents charge the battery pack 12 at the same time.

[0042] Among them, the first positive connection end of the bidirectional DC conversion module 13 and the first negative connection end of the bidirectional DC conversion module 13 can be used as the bus side of the bidirectional DC conversion module 13; the second positive connection end of the bidirectional DC conversion module 13 and the second negative connection end of the bidirectional DC conversion module 13 can be used as the battery side of the bidirectional DC conversion module 13. When the battery pack 12 is in a charging state, the main current enters the battery pack 12 through the bus side of the bidirectional DC conversion module 13, and the battery side current of the bidirectional DC conversion module 13 is small, and the power is less than one tenth of the power of the battery pack 12.

[0043] In some embodiments, when the battery pack 12 is in a discharging state, if the bidirectional DC conversion module 13 corresponding to the battery pack 12 is in a normal state, the battery pack 12 supplies power to the DC bus 11 through the first positive connection end of the corresponding bidirectional DC conversion module 13 and the second negative connection end of the corresponding bidirectional DC conversion module 13.

[0044] In this embodiment, when any battery pack 12 is in a discharging state, if the bidirectional DC conversion module 13 corresponding to the battery pack 12 is in a normal state, that is, it can normally perform the DC conversion function, at this time, the battery pack 12 supplies power to the battery side (the second positive connection terminal) of the corresponding bidirectional DC conversion module 13, and also supplies power to a connection terminal (the first negative connection terminal) on the bus side of the corresponding bidirectional DC conversion module 13. The current is output from the bus side (the first positive connection terminal) of the bidirectional DC conversion module 13 corresponding to the battery pack 12 to the DC bus 11, and flows back to the battery pack 12 from the negative pole of the battery pack 12. At this time, the bidirectional DC conversion module 13 is equivalent to being connected in series with the battery pack 12, and the two ends of the bus side of the bidirectional DC conversion module 13 are equivalent to the positive and negative poles of a battery.

[0045] In this embodiment, the battery pack 12 and the bidirectional DC conversion module 13 are also equivalent to a series relationship in the system, and series charging and discharging management can be realized; and the battery packs 12 are isolated from each other by the bidirectional DC conversion module 13, thereby avoiding current circulation caused by inconsistent performance between the battery packs 12, reducing energy loss, and improving the service life of the system.

[0046] In some embodiments, when the battery pack 12 is in a discharging state, if the bidirectional DC conversion module 13 corresponding to the battery pack 12 is in a failed state, the battery pack 12 supplies power to the DC bus 11 through the body diode of the corresponding bidirectional DC conversion module 13 .

[0047] In this embodiment, when any battery pack 12 is in a discharging state, if the bidirectional DC conversion module 13 corresponding to the battery pack 12 is in a failed state, that is, the DC conversion function cannot be performed normally, which may be caused by device damage and other reasons. At this time, the battery pack 12 can be connected to the corresponding bidirectional DC conversion module 13 through the body diode (for example, Figure 2 The body diodes of each switching tube shown, etc.) supply power to the DC bus 11.

[0048] When one or more battery packs 12 in the DC power supply system are offline, the remaining online battery packs 12 can supply power to the DC bus 11 to ensure the normal operation of the equipment on the DC bus 11. In addition, considering that not only the battery pack 12 has the risk of failure, but also the bidirectional DC conversion module 13 has a certain probability of failure, in the case of failure of the bidirectional DC conversion module 13, the battery pack 12 can also discharge directly to the bus through the diode, which can significantly improve the risk resistance in unexpected situations and improve safety.

[0049] In some embodiments, the bidirectional DC conversion module 13 is a high-frequency transformer electrically isolated bidirectional DC conversion module.

[0050] In some embodiments, see Figure 1 , the DC power supply system also includes an AC / DC conversion module 14;

[0051] The AC end of the AC / DC conversion module 14 is used to connect to an AC power source, the first DC end of the AC / DC conversion module 14 is connected to the DC bus 11 , and the second DC end of the AC / DC conversion module 14 is connected to the negative electrode of the battery pack 12 .

[0052] The AC power source can be an AC power grid or other AC power sources, which are not specifically limited here. The AC-DC conversion module 14 is an AC-DC module, which is used to convert AC power into DC power to supply power to the DC bus 11.

[0053] In some embodiments, the AC-DC conversion module 14 includes at least two AC-DC conversion units connected in parallel.

[0054] When the battery pack 12 is in a charging state, the AC / DC conversion module 14 works normally and is responsible for supplying power to the DC bus 11. The AC / DC conversion module 14 can output a current balance based on the energy required by the DC bus 11 to charge the battery pack 12.

[0055] When the battery pack 12 is in a discharging state, the AC / DC conversion module 14 operates normally. At this time, the energy input to the DC bus 11 by each bidirectional DC conversion module 13 is calculated, and the output energy of the AC / DC conversion module 14 is adjusted to stabilize the power supply capacity of the DC bus 11.

[0056] The DC power supply system provided by the embodiment of the present application has a high and low voltage ride-through function: it can effectively improve some disadvantages of the traditional battery charge and discharge management device. When the AC power supply (grid) fails or disturbs, causing the voltage to rise or fall, resulting in AC high voltage or low voltage power failure, and the AC-DC conversion module 14 cannot output a stable voltage, even if a battery pack 12 is in the charging process, it can also achieve energy direction switching within 100 microseconds, supply power to the DC bus 11, and achieve ride-through without power interruption, that is, within a certain voltage variation range and time interval, it can maintain the ability of the DC bus 11 to operate at a stable voltage. Multiple battery packs 12 are connected in parallel, so that the DC bus 11 can always be in a stable state and achieve stable operation.

[0057] The DC power supply system provided in the embodiment of the present application also has flexible power supply capability: through DC conversion, additional power is input to the DC bus 11 during the discharge of the battery core capacity, or additional power is output from the DC bus 11 during the charging of the core capacity, and the DC bus 11 continuously operates in a voltage-stabilized manner. This enhances the controllability of input / output power input and output and the stability of the bus voltage when the source and load change.

[0058] Through the flexible power supply capability, the controllability of the DC bus 11's voltage-stabilized power supply is enhanced when the battery pack 12 draws energy from the DC bus 11 and supplies energy to the DC bus 11. In addition, the stability of on-demand energy transmission between the battery pack 12 and the DC bus 11 and between the DC bus 11 and the DC load is guaranteed. To ensure system stability, the bidirectional DC conversion module 13 can achieve energy direction switching within 100 microseconds.

[0059] In addition, since the bidirectional DC conversion module 13 has low power, a higher reliability, lower cost and more efficient DC power system management method can be obtained.

[0060] The DC power supply system can realize redundant backup of power supply by freely combining multiple battery packs 12. When the main power supply (battery pack 12) fails or fails, the backup battery pack 12 can immediately take over the load to ensure the continuity of power supply. This redundant design can greatly improve the reliability of the DC power supply system and reduce the risk of equipment downtime or service interruption caused by power failure.

[0061] The DC power supply system can also combine the output currents of multiple battery packs 12 to enhance the overall output capacity, which is very useful for application scenarios that require high current output, ensuring that the load has sufficient power supply and can cope with occasional impact loads.

[0062] The intelligent flexible multi-group free combination battery charge and discharge management device of the DC power supply system has flexible configuration and expansion capabilities, and can adjust the number and configuration of power sources (battery groups 12) according to actual needs and load changes to meet different power needs. This flexibility and scalability makes the system more adaptable to changes in various application scenarios. At the same time, by optimizing power management and control strategies, the intelligent flexible multi-group free combination battery charge and discharge management device can achieve more efficient energy utilization.

[0063] The DC power supply system has centralized monitoring and management functions, which can monitor the working status and performance parameters of the power supply in real time, and provide fault alarm and diagnosis functions, making the maintenance and management of the system easier and more efficient, reducing maintenance costs and manpower investment.

[0064] Corresponding to the above DC power supply system, the embodiment of the present application further provides a control method for controlling any one of the above DC power supply systems; the control method includes:

[0065] When the battery pack is in a charging state, the bidirectional DC conversion module corresponding to the battery pack is controlled so that the DC bus charges the battery pack through the first negative connection terminal of the bidirectional DC conversion module corresponding to the battery pack and the second positive connection terminal of the bidirectional DC conversion module corresponding to the battery pack.

[0066] In some embodiments, the control method may further include:

[0067] Monitor the status of the bidirectional DC conversion module;

[0068] When the battery pack is in a discharging state, if the bidirectional DC conversion module corresponding to the battery pack is in a normal state, the bidirectional DC conversion module corresponding to the battery pack is controlled so that the battery pack supplies power to the DC bus through the first positive connection terminal of the corresponding bidirectional DC conversion module and the second negative connection terminal of the corresponding bidirectional DC conversion module; if the bidirectional DC conversion module corresponding to the battery pack is in a failure state, the battery pack is controlled to supply power to the DC bus through the body diode of the corresponding bidirectional DC conversion module.

[0069] For specific instructions on the control method, please refer to the relevant description in the aforementioned DC power supply system and will not be repeated here.

[0070] Corresponding to the above-mentioned DC power supply system, an embodiment of the present application further provides a power supply device, including any one of the above-mentioned DC power supply systems, and having the beneficial effects of any one of the above-mentioned DC power supply systems.

[0071] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0072] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0073] In the embodiments provided by the present invention, it should be understood that the disclosed devices / systems and methods can be implemented in other ways. For example, the device / system embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0074] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0075] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0076] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various DC power supply system embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium.

[0077] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A DC power supply system, characterized in that: It includes a DC bus, at least two battery packs and at least two bidirectional DC conversion modules; the battery packs correspond to the bidirectional DC conversion modules one by one; the bidirectional DC conversion modules are isolated bidirectional DC conversion modules; The first positive connection end of the bidirectional DC conversion module is connected to the DC bus, the first negative connection end of the bidirectional DC conversion module is connected to the positive pole of the corresponding battery pack, the second positive connection end of the bidirectional DC conversion module is connected to the positive pole of the corresponding battery pack, and the second negative connection end of the bidirectional DC conversion module is connected to the negative pole of the corresponding battery pack.

2. The DC power supply system according to claim 1, characterized in that: When the battery pack is in a charging state, the DC bus charges the battery pack through the first negative connection end of the bidirectional DC conversion module corresponding to the battery pack and the second positive connection end of the bidirectional DC conversion module corresponding to the battery pack.

3. The DC power supply system according to claim 1, characterized in that: When the battery pack is in a discharging state, if the bidirectional DC conversion module corresponding to the battery pack is in a normal state, the battery pack supplies power to the DC bus through the first positive connection end of the corresponding bidirectional DC conversion module and the second negative connection end of the corresponding bidirectional DC conversion module.

4. The DC power supply system according to claim 1, characterized in that: When the battery pack is in a discharging state, if the bidirectional DC conversion module corresponding to the battery pack is in a failure state, the battery pack supplies power to the DC bus through the body diode of the corresponding bidirectional DC conversion module.

5. The DC power supply system according to claim 1, characterized in that: The bidirectional DC conversion module is a high-frequency transformer electrically isolated bidirectional DC conversion module.

6. The DC power supply system according to any one of claims 1 to 5, characterized in that: The DC power supply system also includes an AC-DC conversion module; The AC end of the AC / DC conversion module is used to connect to an AC power source, the first DC end of the AC / DC conversion module is connected to the DC bus, and the second DC end of the AC / DC conversion module is connected to the negative electrode of the battery pack.

7. The DC power supply system according to claim 6, characterized in that: The AC-DC conversion module includes at least two AC-DC conversion units connected in parallel.

8. A control method, characterized in that: Used to control the DC power supply system according to any one of claims 1 to 7; the control method comprises: When the battery pack is in a charging state, the bidirectional DC conversion module corresponding to the battery pack is controlled so that the DC bus charges the battery pack through the first negative connection terminal of the bidirectional DC conversion module corresponding to the battery pack and the second positive connection terminal of the bidirectional DC conversion module corresponding to the battery pack.

9. The control method according to claim 8, characterized in that: The control method further comprises: Monitor the status of the bidirectional DC conversion module; When the battery pack is in a discharging state, if the bidirectional DC conversion module corresponding to the battery pack is in a normal state, the bidirectional DC conversion module corresponding to the battery pack is controlled so that the battery pack supplies power to the DC bus through the first positive connection terminal of the corresponding bidirectional DC conversion module and the second negative connection terminal of the corresponding bidirectional DC conversion module; if the bidirectional DC conversion module corresponding to the battery pack is in a failure state, the battery pack is controlled to supply power to the DC bus through the body diode of the corresponding bidirectional DC conversion module.

10. A power supply device, characterized in that: Comprising a DC power supply system as claimed in any one of claims 1 to 7.

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