Power supply system

Abstract

The input end of the data center power supply system is connected with an alternating current power supply, and the data center power supply system comprises an isolation type alternating current-direct current power supply conversion unit, an isolation type direct current-direct current power supply conversion unit, an energy storage unit, a first direct current bus and a second direct current bus. The isolated DC-DC power supply conversion unit converts a first DC voltage on the first DC bus into a second DC voltage and outputs the second DC voltage to the second DC bus, the main power circuit topology of the isolated DC-DC power supply conversion unit is an LLC circuit or a boost SRC circuit, and the voltage value of the second DC voltage is between 0.5 V and 60V. And the energy storage unit comprises a battery which is electrically connected to the first direct current bus, and when the alternating current-direct current conversion unit works normally, the energy storage unit is charged to a floating charge state. Therefore, the overall power supply conversion efficiency of the scheme is better than that of a conventional system.

Description

Technical Field

[0001] The utility model relates to a power supply system, in particular to a data center power supply system. Background Art

[0002] Data centers are global collaborative networks of specific equipment that play an important role in accelerating the transmission, computing, and storage of data information. As the scale of data centers continues to expand, the required power levels continue to rise, so the market has put forward higher requirements on the efficiency of data center power supply systems.

[0003] Please refer to Figure 1 As shown, Figure 1 1 is a block diagram of a conventional data center power supply system. The AC grid 11 or the generator 12 can generate AC power with a medium voltage AC voltage of 10 kV or above. The AC power is transmitted to the input end of the AC-to-DC power conversion unit 210 of the data center power supply system 200 through the transformer network 13. The AC-to-DC power conversion unit 210 converts the AC power into a first DC voltage Vdc1 on the first DC bus 1, and its voltage value is about 240V. The server power supply 220 is usually equipped with a first AC-to-DC converter 221 and a first DC-to-DC converter 222 that can realize the power factor correction (Power Factor Correction, PFC) function. The server power supply 220 steps down the first DC voltage Vdc1 on the first DC bus 1 and converts it into a second DC voltage Vdc2 on the second DC bus 2. According to the requirements of the load 40, the voltage value of the second DC voltage Vdc2 can usually be 12V or 48V. In addition, a second DC-to-DC converter 30 is connected in series between the load 40 and the second DC bus bus2 to provide voltage reduction and voltage stabilization functions. When the AC power grid 11 or the generator 12 loses power, the energy storage unit 23 connected to the server power supply 220 is started to supply power to the server power supply 220, so that it can continue to work for a period of time, thereby giving the server data time to back up.

[0004] Since the server power supply 220 includes a first AC-to-DC converter 221 and a first DC-to-DC converter 222, this two-stage circuit design reduces the overall power conversion efficiency. Since the number of power conversion levels in the data center power supply system directly affects the power supply efficiency and reliability, there is an urgent need for a system architecture that reduces the number of power conversion levels to meet the power requirements of the data center. Utility Model Content

[0005] The object of the present invention is to provide a data center power supply system. The power supply system is electrically connected to an AC voltage. The AC voltage is first converted into a first DC voltage by an isolated AC-to-DC power conversion unit, and then the first DC voltage is converted into a second DC voltage by a first DC-to-DC converter with a relatively simple circuit structure. Therefore, the present invention can improve the conversion efficiency of the overall power supply system.

[0006] To achieve the aforementioned purpose, the present case provides a power supply system, characterized in that it includes: an isolated AC-to-DC power conversion unit, used to convert the system input AC voltage into a first DC voltage on a first DC bus; an isolated DC-to-DC power conversion unit, electrically connected to the isolated AC-to-DC power conversion unit through the first DC bus, used to convert the first DC voltage on the first DC bus into a second DC voltage, the second DC voltage is used to power a load, wherein the main power circuit topology of the isolated DC-to-DC power conversion unit is an LLC circuit or a boost SRC circuit, and the voltage value of the second DC voltage is between 0.5V and 60V; and an energy storage unit, including a battery, which is electrically connected to the first DC bus, and when the AC-to-DC conversion unit is working normally, the energy storage unit is charged to a floating charge state, so that the voltage value of the first DC voltage is between 380V and 1500V.

[0007] In some embodiments, the voltage value of the first DC voltage is between 800V and 1500V.

[0008] In some embodiments, the voltage value of the first DC voltage is 400V, 800V or 1200V.

[0009] In some embodiments, the system input AC voltage is a medium voltage AC voltage above 10 kV or a low voltage AC voltage between 400 V and 690 V.

[0010] In some embodiments, the voltage value of the second DC voltage is 0.6V-2V, 5V-12V or 50V-60V.

[0011] In some embodiments, the primary side circuit of the LLC circuit or the boost SRC circuit includes two resonant capacitors connected in series between the high voltage end and the low voltage end of the first DC bus, and by setting a grounding point at the connection point of the two resonant capacitors, the 800V voltage on the first DC bus is decomposed into +400V and -400V voltages on the two DC buses, or the 1500V voltage value on the first DC bus is decomposed into +750V and -750V voltages on the two DC buses.

[0012] In some embodiments, the second DC voltage has a voltage value of 12V, 48V, or 54V.

[0013] In some embodiments, the isolated AC-DC power conversion unit includes a cascaded H-bridge rectifier circuit, a plurality of DC decoupling capacitors, and a dual active full-bridge circuit topology.

[0014] In some embodiments, the isolated AC-DC power conversion unit includes a multi-pulse rectifier.

[0015] In some embodiments, the energy storage unit is electrically connected to the first DC bus through a third DC-DC converter.

[0016] In some embodiments, the energy storage unit has a battery for storing energy. When the isolated AC-to-DC power conversion unit does not work properly and the first DC voltage is powered off, the energy storage unit works as the input of the isolated DC-to-DC power conversion unit.

[0017] In some embodiments, the power supply system further includes a second DC-DC converter, the second DC-DC converter having an input end electrically connected to the isolated DC-DC power conversion unit, and an output end of the second DC-DC converter electrically connected to the load.

[0018] In some embodiments, when the power supply system is in a normal working state, the LLC circuit or the boost SRC circuit operates at a resonance point.

[0019] In some embodiments, the LLC circuit or the boost SRC circuit has a primary side circuit and a secondary side circuit, the primary side circuit has at least one inverter circuit, at least one inverter circuit is a full-bridge inverter circuit or a half-bridge inverter circuit, and the secondary side circuit has at least one rectifier circuit, at least one rectifier circuit is a full-bridge rectifier circuit or a full-wave rectifier circuit.

[0020] In some embodiments, the LLC circuit or the boost SRC circuit has a primary side circuit and a secondary side circuit, the primary side circuit has multiple inverter circuits, and the multiple inverter circuits are connected in parallel, series or staggered parallel; the secondary side circuit has multiple rectifier circuits, and the multiple rectifier circuits are connected in parallel, series or staggered parallel.

[0021] In some embodiments, the power supply system further includes at least one fourth DC-DC converter, and the first DC bus is electrically connected to a fuel cell or a solar panel through the fourth DC-DC converter.

[0022] In some embodiments, the power supply system further includes at least one second AC-to-DC converter, and the first DC bus is electrically connected to a wind generator through the second AC-to-DC converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A block diagram of a conventional data center power supply system;

[0024] Figure 2 A block diagram of a data center power supply system according to a first preferred embodiment of the present invention;

[0025] Figure 3 A block diagram of a data center power supply system according to a second preferred embodiment of the present invention;

[0026] Figure 4 A block diagram of a data center power supply system according to a third preferred embodiment of the present invention;

[0027] Figure 5 The circuit diagram of the main power circuit of the isolated AC-DC power conversion unit of the first preferred embodiment of the present invention is

[0028] Figure 6 A circuit diagram of a main power circuit of an isolated AC-to-DC power conversion unit according to a second preferred embodiment of the present invention;

[0029] Figure 7a A main power circuit topology diagram of an isolated DC-DC power conversion unit according to the first preferred embodiment of the present invention;

[0030] Figure 7b A main power circuit topology diagram of an isolated DC-DC power conversion unit according to a second preferred embodiment of the present invention;

[0031] Figure 7c A main power circuit topology diagram of an isolated DC-DC power conversion unit according to the third preferred embodiment of the present invention;

[0032] Figure 7d A main power circuit topology diagram of an isolated DC-DC power conversion unit according to a fourth preferred embodiment of the present invention;

[0033] Figure 8 A main power circuit topology diagram of an isolated DC-DC power conversion unit according to a fifth preferred embodiment of the present invention;

[0034] Figure 9a A main power circuit topology diagram of an isolated DC-DC power conversion unit according to a sixth preferred embodiment of the present invention;

[0035] Figure 9b A main power circuit topology diagram of an isolated DC-DC power conversion unit according to the seventh preferred embodiment of the present invention;

[0036] Fig.9c A main power circuit topology diagram of an isolated DC-DC power conversion unit according to an eighth preferred embodiment of the present invention; and

[0037] Figure 9d This is a main power loop circuit topology diagram of the isolated DC-DC power conversion unit of the ninth preferred embodiment of the present invention.

[0038] The reference numerals are described as follows:

[0039] 11: AC power grid

[0040] 12: Generator

[0041] 13: Transformer network

[0042] 20: Power supply system

[0043] 21: Isolated AC to DC power conversion unit

[0044] 21a, 21b: Isolated circuit topology

[0045] 22a: Cascade H-bridge rectifier circuit

[0046] 23a: Dual Active Full-Bridge Topology

[0047] bus1: first DC bus

[0048] 22: Server power supply

[0049] 41a, 41a', 41b, 41c, 41c', 41d: primary side circuit

[0050] 42a, 42a', 42b, 42b', 42c, 42c', 42d: secondary side circuit

[0051] 221: The first AC-to-DC converter

[0052] 222: The first DC-DC converter

[0053] 30: Second DC-DC converter

[0054] 223: Isolated DC-DC power conversion unit

[0055] bus2: second DC bus

[0056] 23: Energy storage unit

[0057] 24: The third DC-DC converter

[0058] 25: New energy power supply unit

[0059] 251: Second AC to DC converter

[0060] 252: The fourth DC-DC converter

[0061] 40: Load

[0062] Vdc1: First DC voltage

[0063] Vdc2: Second DC voltage

[0064] Cde: DC decoupling capacitor

[0065] S1~S6:switch

[0066] D1~D6:Diode

[0067] Cr, Cr1~Cr3: resonant capacitor

[0068] Lr, Lr1~Lr3: resonant inductance

[0069] Lm, Lm1~Lm3: magnetizing inductance

[0070] Co: filter capacitor

[0071] Vo: output voltage

[0072] Ro: Load DETAILED DESCRIPTION

[0073] Some typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different aspects without departing from the scope of the present invention, and the descriptions and drawings are essentially for illustrative purposes rather than for limiting the present invention.

[0074] Please refer to Figure 2 . Figure 2 The block diagram of the power supply system of the first preferred embodiment of the present invention. The data center power supply system 20 of the present invention includes an isolated AC-to-DC power conversion unit 21, an isolated DC-to-DC power conversion unit 223, and an energy storage unit 23. Among them, the isolated DC-to-DC power conversion unit 223 is included in the server power supply 22. The AC grid 11 or the generator 12 generates medium-voltage AC power of a level above 10kV, which is converted into the system input voltage of the power supply system 20 through the transformer network 13 and then transmitted to the input end of the isolated AC-to-DC power conversion unit 21. The system input voltage is a medium-voltage AC voltage above 10kV or a low-voltage AC voltage between 400V and 690V. The isolated AC-to-DC power conversion unit 21 converts the system input AC voltage into a first DC voltage Vdc1 on the first DC bus bus1. In addition to realizing the isolation or step-down rectification function, the isolated AC-to-DC power conversion unit 21 can also realize the power factor correction function.

[0075] Compared to Figure 1The conventional server power supply 220 includes a first AC-DC converter 221 and a first DC-DC converter 222, which are two-stage power conversion circuits. Figure 2 The server power supply 22 in the embodiment only includes an isolated DC-DC power conversion unit 223, which is used to realize step-down conversion and convert the first DC voltage Vdc1 into a second DC voltage Vdc2 with a voltage value between 0.5V and 60V on the second DC bus bus2. Accordingly, the power supply system 20 of the present case is greatly simplified in circuit architecture compared to the current conventional power supply system 220, and the construction cost of the data center can be greatly reduced. In addition, the server power supply 22 of the present case is not only greatly simplified in circuit architecture compared to the current conventional server power supply 220, but more importantly, the power conversion efficiency can be greatly improved, which is even more important in the future market when a large number of server power supplies are needed, and can greatly reduce energy loss and waste. In some specific embodiments, the voltage value of the second DC voltage Vdc2 is 0.6V-2V, 5V-12V or 50V-60V.

[0076] The energy storage unit 23 is electrically connected to the first DC bus1 between the isolated AC-to-DC power conversion unit 21 and the isolated DC-to-DC power conversion unit 223 in the power supply system 20. The energy storage unit 23 can be, for example, a large energy storage cabinet (ESS), which has a battery inside for energy storage. When the isolated AC-to-DC power conversion unit 21 does not work properly and the first DC voltage Vdc1 loses power, the energy storage unit 23 works as the input of the isolated DC-to-DC power conversion unit 223 to prevent the voltage Vdc1 on the first DC bus1 from dropping rapidly; when the isolated AC-to-DC conversion unit 21 works normally, the energy storage unit 23 is charged to a floating charge state, so that the voltage value of the first DC voltage Vdc1 is between 380V and 1500V. Floating charge is a continuous, long-term low-current charging mode that can keep the battery in a fully charged state at all times. In some embodiments, the voltage value of the first DC voltage Vdc1 is between 800V and 1500V. In other embodiments, the voltage value of the first DC voltage Vdc1 is 400 V, 800 V or 1200 V. In other embodiments, the energy storage unit 23 may be a super capacitor.

[0077] As mentioned above, this case Figure 2 Compared with the existing conventional power supply system Figure 1 The power supply system of the server power supply reduces one level of power conversion circuit, that is, there is no longer a first AC to DC converter 221, thereby improving the overall power supply efficiency and reliability.

[0078] When the load 40 is a component that needs to provide a large current in a short time, such as a central processing unit (CPU), a second DC-DC converter 30 may be additionally provided, which may be, for example, a common point-of-load (POL) power supply or a voltage regulator module (VRM). The input end of the second DC-DC converter 30 is electrically connected to the output end of the isolated DC-DC power conversion unit 223, and the output end of the second DC-DC converter 30 is electrically connected to the load 40 to provide the voltage required by the load 40, which is usually less than 1V, so that the load 40 can work normally.

[0079] refer to Figure 3 , is a block diagram of a power supply system of a second preferred embodiment of the present invention. The power supply system 20 includes Figure 2 In addition to the circuit unit shown, a third DC-DC converter 24 may also be disposed between the first DC bus1 and the energy storage unit 23 to perform voltage stabilization or protection operations for battery charging and discharging.

[0080] Please refer to Figure 4 , is a block diagram of the power supply system of the third preferred embodiment of the present invention. With the widespread application of new energy technologies, the first DC bus1 in the power supply system 20 can also be used to connect to at least one or more of the new energy power supply units 25 such as wind power, solar energy and fuel cells. For example, Figure 4 As shown, the first DC bus1 in the power supply system 20 can be connected to at least one second AC-to-DC converter 251 and at least one fourth DC-to-DC converter 252, which are respectively used to connect to one or more of a wind turbine, a solar panel, and a fuel cell. Specifically, a fuel cell or a solar panel can be electrically connected to the first DC bus1 through at least one fourth DC-to-DC converter 252, and the fourth DC-to-DC converter 252 can provide a buck-boost or circuit voltage stabilization protection function. A wind turbine can be electrically connected to the first DC bus1 through at least one second AC-to-DC converter 251, and the second AC-to-DC converter 251 can provide a buck-boost or circuit voltage stabilization protection function.

[0081] Figure 5 1 is a circuit diagram of the main power circuit of the isolated AC-DC power conversion unit of the first preferred embodiment of the present invention. The main power circuit topology of the isolated AC-DC power conversion unit 21 can be as follows: Figure 5 The isolated circuit topology 21a shown or Figure 6The isolated circuit topology 21b is shown. The isolated circuit topology 21a is mainly composed of a cascaded H-bridge (CHB) rectifier circuit 22a, multiple DC decoupling capacitors Cde and an isolated modulation voltage circuit 23a. Among them, the isolated modulation voltage circuit 23a usually uses a soft switching topology, which can realize soft switching of switching devices and has high efficiency. Specifically, the isolated modulation voltage circuit 23a is a dual active full bridge circuit topology (DAB). Usually, the isolated AC-DC circuit will increase the Figure 5 The DC decoupling capacitor Cde is shown to decouple AC and DC power. In some embodiments, a modular multilevel converter (MMC) may also be used for rectification.

[0082] Figure 6 2 is a circuit diagram of the main power circuit of the isolated AC-DC power conversion unit of the second preferred embodiment of the present invention. The main power circuit topology of the isolated AC-DC power conversion unit 21 can be as follows: Figure 6 The isolated circuit topology 21b shown in FIG. 2 includes a multi-pulse rectifier (MPR) and is usually composed of multiple groups of three-phase rectifier bridges. The phase difference between the input voltages of each group of rectifier bridges is 360° / N. Figure 6 In the 18-pulse rectifier shown, the input voltage phase difference of each group of rectifier bridges is 20° (360° / 18=20°). Compared with PWM rectifier, MPR has the advantages of simple implementation, low cost and high reliability, and has been widely used in high-power rectifier systems.

[0083] Please refer to Figure 7a , Figure 7b , Figure 7c and Figure 7d The following are the main power circuit topology diagrams of the isolated DC-DC power conversion unit in the first to fourth preferred embodiments of the present invention. Figure 7a as well as Figure 7cThe main power circuit topology of the isolated DC-DC power conversion unit 223 is an LLC circuit, which includes primary side circuits 41a, 41b and secondary side circuits 42a, 42b. The primary side circuit has at least one inverter circuit, which is a full-bridge inverter circuit or a half-bridge inverter circuit. For example, the primary side circuit 41a is a full-bridge inverter circuit, which is composed of 4 switches S1-S4, a resonant capacitor Cr, a resonant inductor Lr and an exciting inductor Lm. The primary side circuit 41b is a half-bridge inverter circuit, which is composed of 2 switches S1-S2, a resonant capacitor Cr, a resonant inductor Lr and an exciting inductor Lm. The secondary circuit has at least one rectifier circuit, which is a full-bridge rectifier circuit or a full-wave rectifier circuit. For example, the secondary circuit 42a is a full-bridge rectifier circuit, which is composed of four diodes D1-D4 and a filter capacitor Co, and the secondary circuit 42b is a full-wave rectifier circuit, which is composed of two diodes D1-D2 and a filter capacitor Co. Figure 7a In the embodiment, the primary circuit 41a and the secondary circuit 42a are combined to form a complete LLC circuit, an output voltage Vo is formed at the output end, and power is provided to the load Ro. Figure 7c In the embodiment, the primary circuit 41b and the secondary circuit 42b form a complete LLC circuit, an output voltage Vo is formed at the output end, and power is provided to the load Ro. Figure 7b middle Figure 7a The diodes D1 to D4 of the secondary side circuit 42a can be replaced by MOS (metal-oxide-semiconductor) field effect transistors SR1 to SR4, generally referred to as MOS transistors, to form Figure 7b The secondary side circuit 42a' in the embodiment also has a rectifying function and can reduce the conduction loss. Figure 7d middle, Figure 7c The diodes D1-D2 of the secondary side circuit 42b can be replaced by MOS tubes SR1-SR2 to form Figure 7d The secondary side circuit 42b' in the embodiment also has a rectifying function and can reduce the conduction loss. In some embodiments, the MOS tube can also be replaced by other types of switch tubes such as IGBT that can achieve the same function.

[0084] Please refer to Figure 8 , Figure 8 The main power circuit topology of the isolated DC-DC power conversion unit of the fifth preferred embodiment of the present invention. The main power circuit topology of the isolated DC-DC power conversion unit 223 of the present embodiment is a boost series resonant converter (BOOST-SRC) circuit, which has a primary side circuit 41a' and a secondary side circuit 42a'. The primary side circuit 41a' and the secondary side circuit 42a' are shown in FIG. Figure 7a or Figure 7b The primary circuit 41a in FIG. 1 is similar to the primary circuit 41a in FIG. 1, but the LLC resonant tank is changed to be a series resonant capacitor Cr and a resonant inductor Lr. The secondary circuit 42a' can be connected to Figure 7b The full-bridge rectifier circuit with the same secondary side circuit as in Figure 7d The full-wave rectifier circuit of the secondary side circuit 42 in the boost SRC circuit does not require the participation of the magnetizing inductor Lm of the inverter circuit, so a gapless transformer can be used to improve the loss and circuit efficiency.

[0085] In addition, whether Figures 7a to 7d The LLC circuit shown or Figure 8 The combination of the primary side circuit and the secondary side circuit of the BOOST-SRC circuit shown in the figure can be limited to Figures 7a to 7d or Figure 8 In this way, the full-bridge inverter circuit or half-bridge inverter circuit of the primary side circuit can have multiple groups, and the full-bridge rectifier circuit or full-wave rectifier circuit of the secondary side circuit can also have multiple groups. For example, taking the LLC circuit as an example, please refer to Figure 9a as well as Figure 9b As shown in Figure 9a In the embodiment, the primary circuit 41c has two sets of half-bridge inverter circuits, which are connected in series to form the primary circuit 41c, and the secondary circuit 42c has two sets of full-wave rectifier circuits, which are connected in parallel to form the secondary circuit 42c. Figure 9a In the example, the primary circuit 41c is composed of 4 switches S1-S4, 2 resonant capacitors Cr1, Cr2, 2 resonant inductors Lr1, Lr2 and 2 magnetizing inductors Lm1, Lm2, while the secondary circuit 42c is composed of 4 diodes D1-D4 and a filter capacitor Co. The output end thereof forms an output voltage Vo and provides power to the load Ro. Figure 9b In the LLC circuit, the grounding point of the primary circuit 41c' can be set at the midpoint of the two series-connected resonant capacitors Cr1 and Cr2, thereby decomposing the 800V voltage on the first DC bus1 into +400V and -400V voltages on the two DC buses, or decomposing the 1500V voltage on the first DC bus1 into +750V and -750V voltages on the two DC buses. Fig.9c In the embodiment, the LLC circuit may be a series half-bridge LLC (SHB-LLC) topology, and the secondary side circuit 42c' may have only one set of full-wave rectifier circuits.

[0086] At Figure 9dIn the embodiment, the primary circuit 41d has three groups of half-bridge inverter circuits, which are connected in parallel in an interlaced manner to form the primary circuit 41d, and the secondary circuit 42d has three groups of full-wave rectifier circuits, which are connected in parallel to form the secondary circuit 42d. Figure 9d In the figure, the primary side circuit 41d is composed of 6 switches S1~S6, 3 resonant capacitors Cr1~Cr3, 3 resonant inductors Lr1~Lr3 and 3 excitation inductors Lm1~Lm3, and the secondary side circuit 42d is composed of 6 diodes D1~D6 and a filter capacitor Co. An output voltage Vo is formed at its output end and power is provided to the load Ro.

[0087] In summary, this case provides a power supply system. Since the server power supply only includes a first-level isolated DC-DC power conversion unit, there is no need to use the conventional AC-DC converter, and the main power circuit topology of the isolated DC-DC power conversion unit adopts an LLC circuit or a boost SRC circuit. When the power supply system is in normal working state, the LLC circuit or the boost SRC circuit is controlled to work at the resonance point, so the conversion efficiency of the server power supply is higher than that of the conventional solution, thereby further improving the conversion efficiency of the overall power supply system. When the system input voltage is powered off or the load suddenly changes, the energy storage unit electrically connected to the first DC bus responds quickly to provide input for the server power supply to improve the reliability of the power supply system.

[0088] The present invention can be modified in various ways by those skilled in the art, but all of them are within the protection of the attached claims.

Claims

1. A power supply system, characterized in that: include: an isolated AC-to-DC power conversion unit, used for converting a system input AC voltage into a first DC voltage on a first DC bus; an isolated DC-DC power conversion unit, electrically connected to the isolated AC-DC power conversion unit through the first DC bus, for converting a first DC voltage on the first DC bus into a second DC voltage, the second DC voltage being used to supply power to a load, wherein a main power circuit topology of the isolated DC-DC power conversion unit is an LLC circuit or a boost SRC circuit, and a voltage value of the second DC voltage is between 0.5V and 60V; and An energy storage unit includes a battery, which is electrically connected to the first DC bus. When the AC-to-DC conversion unit works normally, the energy storage unit is charged to a floating charge state, so that the voltage value of the first DC voltage is between 380V and 1500V.

2. The power supply system according to claim 1, characterized in that: The voltage value of the first DC voltage is between 800V and 1500V.

3. The power supply system according to claim 1, characterized in that: The voltage value of the first DC voltage is 400V, 800V or 1200V.

4. The power supply system according to claim 1, characterized in that: The system input AC voltage is a medium voltage AC voltage above 10kV or a low voltage AC voltage between 400V and 690V.

5. The power supply system according to claim 1, characterized in that: The voltage value of the second DC voltage is 0.6V-2V, 5V-12V or 50V-60V.

6. The power supply system according to claim 1, characterized in that: The primary side circuit of the LLC circuit or the boost SRC circuit includes two resonant capacitors connected in series between the high voltage end and the low voltage end of the first DC bus. By setting a grounding point at the connection point of the two resonant capacitors, the 800V voltage on the first DC bus is decomposed into +400V and -400V voltages on two DC buses, or the 1500V voltage value on the first DC bus is decomposed into +750V and -750V voltages on two DC buses.

7. The power supply system according to claim 1, characterized in that: The voltage value of the second DC voltage is 12V, 48V or 54V.

8. The power supply system according to claim 1, characterized in that: The isolated AC-to-DC power conversion unit includes a cascaded H-bridge rectifier circuit, a plurality of DC decoupling capacitors and a dual active full-bridge circuit topology.

9. The power supply system according to claim 1, characterized in that: The isolated AC-to-DC power conversion unit includes a multi-pulse rectifier.

10. The power supply system according to claim 1, characterized in that: The energy storage unit is electrically connected to the first DC bus through a third DC-DC converter.

11. The power supply system according to claim 1, characterized in that: The energy storage unit has a battery for storing energy. When the isolated AC-to-DC power conversion unit does not work normally and the first DC voltage is powered off, the energy storage unit works as the input of the isolated DC-to-DC power conversion unit.

12. The power supply system according to claim 1, characterized in that: The device further comprises a second DC-DC converter, wherein the second DC-DC converter has an input terminal electrically connected to the isolated DC-DC power conversion unit, and an output terminal of the second DC-DC converter is electrically connected to the load.

13. The power supply system according to claim 1, characterized in that: When the power supply system is in a normal working state, the LLC circuit or the boost SRC circuit operates at a resonance point.

14. The power supply system according to claim 1, characterized in that: The LLC circuit or the boost SRC circuit has a primary side circuit and a secondary side circuit, the primary side circuit has at least one inverter circuit, the at least one inverter circuit is a full-bridge inverter circuit or a half-bridge inverter circuit, and the secondary side circuit has at least one rectifier circuit, the at least one rectifier circuit is a full-bridge rectifier circuit or a full-wave rectifier circuit.

15. The power supply system according to claim 1, characterized in that: The LLC circuit or the boost SRC circuit has a primary side circuit and a secondary side circuit, the primary side circuit has a plurality of inverter circuits, and the plurality of inverter circuits are connected in parallel, in series or in staggered parallel; the secondary side circuit has a plurality of rectifier circuits, and the plurality of rectifier circuits are connected in parallel, in series or in staggered parallel.

16. The power supply system according to claim 1, characterized in that: The power supply system further includes at least one fourth DC-DC converter, and the first DC bus is electrically connected to a fuel cell or a solar panel through the fourth DC-DC converter.

17. The power supply system according to claim 1, characterized in that: The power supply system further includes at least one second AC-to-DC converter, and the first DC bus is electrically connected to a wind generator through the second AC-to-DC converter.

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