Bidirectional Buck-Boost circuit suitable for data center

Abstract

The invention belongs to the technical field of energy storage, and particularly relates to a bidirectional Buck-Boost circuit suitable for a data center, which comprises a bidirectional Buck-Boost circuit consisting of a first input / output capacitor, a second input / output capacitor, a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and a first inductor, and the auxiliary branch consists of a fifth switch tube, a sixth switch tube and a second inductor. According to the invention, the voltage across the two ends of the first inductor is increased when the circuit is in a forward Buck or reverse Boost working mode, so that the rising rate or the falling rate of the current in the circuit is improved, the output current of the circuit is rapidly adjusted under the condition that the output voltage of the circuit is kept relatively stable, and the power change requirement of a load is dynamically responded. Meanwhile, in the process, voltage fluctuation on the first input / output capacitor or the second input / output capacitor is restrained through the auxiliary branch, and it is ensured that the circuit works reliably, stably and continuously.

Description

Technical Field

[0001] This invention belongs to the field of energy storage technology, specifically relating to a bidirectional Buck-Boost circuit suitable for data centers. Background Technology

[0002] A bidirectional DC / DC converter is a power electronic device that enables the bidirectional flow of energy between two DC power sources, possessing both voltage conversion and bidirectional energy transfer capabilities. Specific applications include energy recovery in electric vehicles, energy storage systems, and renewable energy systems. Key technical specifications include efficiency, power rating, and dynamic response performance.

[0003] However, for some special application scenarios, such as data center power supply systems, where data centers face the problem of drastic load fluctuations under different operating conditions, certain requirements are placed on the dynamic response capability of DC / DC converters.

[0004] Furthermore, the booming development of data centers has also driven the rapid growth in the scale of Uninterruptible Power Supplies (UPS). However, in most cases, the UPS systems configured in data centers are idle. Therefore, while ensuring reliable power supply to data centers, further research can be conducted on using UPS as energy storage to actively support the power grid, thereby effectively improving UPS utilization. Specifically, UPS systems can be composed of a single energy storage component or a combination of different energy storage components. These energy storage components include, but are not limited to, lead-acid batteries, lithium-ion batteries (including but not limited to lithium iron phosphate batteries, ternary lithium batteries, lithium titanate batteries, etc.), sodium-ion batteries, lithium metal batteries, semi-solid-state batteries, solid-state batteries, double-layer capacitors, and lithium-ion capacitors.

[0005] In order to enable UPS to actively support the power grid, a bidirectional DC / DC converter is required. Furthermore, to enable UPS to quickly support the power grid, the dynamic response capability of the DC / DC converter is also challenged. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this invention is to propose a bidirectional DC / DC converter with fast dynamic response capability, which can achieve fast dynamic response and low voltage fluctuation while transmitting energy bidirectionally, and is applicable to application scenarios including but not limited to data center power supply systems.

[0007] To achieve the above and other related objectives, the present invention provides a bidirectional Buck-Boost circuit suitable for data centers, comprising: a first input / output capacitor; a second input / output capacitor; a first switch transistor, one end of which is connected to one end of the first input / output capacitor; a second switch transistor, one end of which is connected to the other end of the first switch transistor, and the other end of which is connected to the other ends of both the first and second input / output capacitors; a first inductor, one end of which is connected to the other ends of both the first and second switch transistors; and a third switch transistor, one end of which is connected to the other end of the first inductor, and the other end of which is connected to the first input / output capacitor; The other end of the output capacitor is connected to the other end of the second input / output capacitor; the fourth switch has one end connected to the other end of the first inductor and one end of the third switch, and the other end connected to one end of the second input / output capacitor; the fifth switch has one end connected to one end of the first input / output capacitor; the sixth switch has one end connected to the other end of the fifth switch, and the other end connected to the other end of the first input / output capacitor and the other end of the second input / output capacitor; the second inductor has one end connected to the other end of the fifth switch and one end of the sixth switch, and the other end connected to one end of the second switch.

[0008] According to a specific embodiment of the present invention, the circuit formed by the fifth switch, the sixth switch, and the second inductor serves as an auxiliary branch between the first input / output capacitor and the second input / output capacitor; wherein, by adjusting the duty cycle between the fifth switch and the sixth switch, the auxiliary branch is made to operate in Buck mode or Boost mode to suppress voltage fluctuations on the first input / output capacitor or the second input / output capacitor.

[0009] According to a specific embodiment of the present invention, the bidirectional Buck-Boost circuit suitable for data centers includes at least a forward Buck operating mode; wherein, when the bidirectional Buck-Boost circuit suitable for data centers is in the forward Buck operating mode, the power supply on the first input / output capacitor side is used to step down the load power supply on the second input / output capacitor side.

[0010] According to a specific embodiment of the present invention, when the bidirectional Buck-Boost circuit suitable for data centers is in the forward Buck operating mode, it operates according to the following condition: In condition one, the first switch and the second switch are alternately turned on, the third switch is always turned off, the fourth switch is always turned on, the fifth switch is always turned off, and the sixth switch is always turned off.

[0011] According to a specific embodiment of the present invention, when the current output of the bidirectional Buck-Boost circuit suitable for data centers needs to be increased, it operates according to the following operating condition two: In operating condition two, the first switch is constantly on, the second switch is constantly off, the third switch is constantly on, the fourth switch is constantly off, and the fifth and sixth switches are alternately on, so that the voltage on the first inductor is the same as the voltage on the first input / output capacitor, thereby accelerating the rate of increase of the current flowing through the first inductor; wherein, the auxiliary branch composed of the fifth switch, the sixth switch, and the second inductor is in a positive Buck operating mode to charge the second input / output capacitor; when the current flowing through the first inductor reaches the current output size required by the load from the bidirectional Buck-Boost circuit suitable for data centers, the bidirectional Buck-Boost circuit suitable for data centers is controlled to switch from operating condition two to operating condition one, so that the current flowing through the first inductor flows to the load.

[0012] According to a specific embodiment of the present invention, when the current output of the bidirectional Buck-Boost circuit suitable for data centers needs to be reduced, it operates according to the following operating condition three: In operating condition three, the first switch is constantly off, the second switch is constantly on, the third switch is constantly off, the fourth switch is constantly on, and the fifth and sixth switches are alternately on, so that the voltage on the first inductor is negative than the voltage on the second input / output capacitor, thereby accelerating the rate of decrease of the current flowing through the first inductor; wherein, the auxiliary branch composed of the fifth switch, the sixth switch, and the second inductor is in reverse Boost operating mode to discharge the second input / output capacitor; when the current flowing through the first inductor reaches the current output size required by the load of the bidirectional Buck-Boost circuit suitable for data centers, the bidirectional Buck-Boost circuit suitable for data centers switches from operating condition three to operating condition one to prevent the current flowing through the first inductor from continuing to decrease.

[0013] According to a specific embodiment of the present invention, the bidirectional Buck-Boost circuit suitable for data centers includes at least a reverse Boost operating mode; wherein, when the bidirectional Buck-Boost circuit suitable for data centers is in the reverse Boost operating mode, the power supply on the second input / output capacitor side is used to boost the load on the first input / output capacitor side.

[0014] According to a specific embodiment of the present invention, when the bidirectional Buck-Boost circuit suitable for data centers is in the reverse Boost working mode, it operates according to the following condition: In condition one, the first switch is always on, the second switch is always off, the third and fourth switches are alternately on, the fifth switch is always off, and the sixth switch is always off.

[0015] According to a specific embodiment of the present invention, when the output current of the bidirectional Buck-Boost circuit suitable for data centers needs to be increased, it operates according to the following operating condition two: In operating condition two, the first switch is constantly off, the second switch is constantly on, the third switch is constantly off, the fourth switch is constantly on, and the fifth and sixth switches are alternately on, so that the voltage on the first inductor is the same as the voltage on the second input / output capacitor, thereby accelerating the rise rate of the current flowing through the first inductor; wherein, the auxiliary branch composed of the fifth switch, the sixth switch, and the second inductor is in reverse Boost operating mode to charge the first input / output capacitor; when the current flowing through the first inductor reaches the current output size required by the load from the bidirectional Buck-Boost circuit suitable for data centers, the bidirectional Buck-Boost circuit suitable for data centers is controlled to switch from operating condition two to operating condition one, so that the current flowing through the first inductor flows to the load.

[0016] According to a specific embodiment of the present invention, when the current output of the bidirectional Buck-Boost circuit suitable for data centers needs to be reduced, it operates according to the following operating condition three: In operating condition three, the first switch is constantly on, the second switch is constantly off, the third switch is constantly on, the fourth switch is constantly off, and the fifth and sixth switches are alternately on, so that the voltage on the first inductor is negative compared to the voltage on the first input / output capacitor, thereby accelerating the rate of decrease of the current flowing through the first inductor; wherein, the auxiliary branch composed of the fifth switch, the sixth switch, and the second inductor is in a positive Buck operating mode to discharge the first input / output capacitor; when the current flowing through the first inductor reaches the current output size required by the load of the bidirectional Buck-Boost circuit suitable for data centers, the bidirectional Buck-Boost circuit suitable for data centers switches from operating condition three to operating condition one to prevent the current flowing through the first inductor from continuing to decrease.

[0017] This invention provides a bidirectional Buck-Boost circuit suitable for data centers, which can support rapid dynamic response in both forward Buck and reverse Boost modes to quickly meet changes in load power demand and effectively improve UPS utilization. Attached Figure Description

[0018] Figure 1 The circuit topology diagram is shown in a specific embodiment of a bidirectional Buck-Boost circuit suitable for data centers provided by the present invention.

[0019] Figure 2 The circuit topology diagram of a specific embodiment of a bidirectional Buck-Boost circuit suitable for data centers provided by the present invention in the positive Buck operating mode is shown below.

[0020] Figure 3 The circuit topology diagram of another specific embodiment of the bidirectional Buck-Boost circuit suitable for data centers provided by the present invention in the positive Buck operating mode;

[0021] Figure 4 The circuit topology diagram of another specific embodiment of the bidirectional Buck-Boost circuit suitable for data centers provided by the present invention in the positive Buck operating mode is shown below.

[0022] Figure 5 This is a schematic diagram illustrating a specific application scenario of a bidirectional Buck-Boost circuit suitable for data centers, as provided by the present invention. Detailed Implementation

[0023] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0025] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0026] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0027] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0028] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0029] Please see Figure 1 The illustrated bidirectional Buck-Boost circuit for data centers includes: a first input / output capacitor C bus Second input / output capacitor C ups First switch S1, second switch S2, third switch S3, fourth switch S4, fifth switch S5, sixth switch S6, first inductor L i and the second inductor L x .

[0030] Among them, the first input / output capacitor C bus Second input / output capacitor C ups The first switch S1, the second switch S2, the third switch S3, the fourth switch S4, and the first inductor L i This forms a bidirectional Buck-Boost circuit, namely:

[0031] One end of the first switch S1 is connected to the first input / output capacitor C. bus One end is connected, and the other end is connected to the first inductor L. iOne end of the transistor is connected to one end of the first input / output capacitor C, and the other end of the second switch S2 is connected to one end of the first input / output capacitor C. bus The other end, and the second input / output capacitor C ups The other end is connected to the first inductor L i The other end is connected to one end of the third switch S3 and one end of the fourth switch S4, respectively, and the other end of the third switch S3 is connected to the first input / output capacitor C. bus The other end, and the second input / output capacitor C ups The other end is connected, and the other end of the fourth switch S4 is connected to the second input / output capacitor C. ups One end is connected.

[0032] It is understandable that the first input / output capacitor C is usually... bus It is connected in parallel across two ends of a DC power supply, while the second input / output capacitor C ups It is connected in parallel across the two ends of another DC power source, thereby enabling the transfer of electrical energy between the two DC power sources.

[0033] Therefore, when this part of the circuit requires forward power, it is only necessary to keep the third switch S3 constantly off and the fourth switch S4 constantly on. Then, by controlling the first switch S1 and the second switch S2 to alternately turn on, the power supply from the first input / output capacitor C can be achieved. bus One-way second input / output capacitor C ups The circuit provides forward power from one side, and by adjusting the duty cycles of the first switch S1 and the second switch S2, it can achieve either boost or buck power supply. For example, when the duty cycle of the first switch S1 is less than 0.5, the corresponding duty cycle of the second switch S2 is greater than 0.5, and the circuit is in forward buck power supply mode, i.e., operating in forward Buck mode; when the duty cycle of the first switch S1 is greater than 0.5, the corresponding duty cycle of the second switch S2 is less than 0.5, and the circuit is in forward boost power supply mode, i.e., operating in forward Boost mode.

[0034] Alternatively, by keeping the first switch S1 constantly on and the second switch S2 constantly off, and then controlling the third switch S3 and the fourth switch S4 to alternately turn on, the first input / output capacitor C can also be controlled. bus One-sided second input / output capacitor C ups The forward power supply on one side can be boosted or bucked by adjusting the duty cycle of the third switch S3 and the fourth switch S4. The working principle is basically the same as the circuit structure of the forward power supply described above, so it will not be described in detail here.

[0035] When the circuit is powered in reverse, it is only necessary to keep the first switch S1 constantly on and the second switch S2 constantly off. Then, by controlling the third switch S3 and the fourth switch S4 to be turned on alternately, the second input / output capacitor C can be used to achieve the desired effect. ups One side of the first input / output capacitor C bus The circuit supports reverse power supply on one side, and can achieve either boost or buck power supply by adjusting the duty cycles of the third switch S3 and the fourth switch S4. For example, when the duty cycle of the fourth switch S4 is less than 0.5, that is, when the duty cycle of the third switch S3 is greater than 0.5, the circuit is in reverse buck power supply mode, i.e., operating in reverse Buck mode; when the duty cycle of the fourth switch S4 is greater than 0.5, that is, when the duty cycle of the third switch S3 is less than 0.5, the circuit is in reverse boost power supply mode, i.e., operating in reverse Boost mode.

[0036] Similarly, by keeping the third switch S3 constantly off and the fourth switch S4 constantly on, and by controlling the first switch S1 and the second switch S2 to alternately turn on, the second input / output capacitor C can also be controlled. ups One side of the first input / output capacitor C bus The reverse power supply on one side will not be discussed in detail.

[0037] It should be noted that the duty cycle descriptions for the switching transistors in Buck and Boost modes above are for reference only. In actual applications, the dead time between the switching transistors also needs to be considered, and the corresponding duty cycle cannot reach 0.5 to avoid the switching transistors from conducting simultaneously.

[0038] Furthermore, the fifth switch S5, the sixth switch S6, and the second inductor L x This forms an auxiliary branch, namely: one end of the fifth switch S5 is connected to the first input / output capacitor C. bus One end is connected, and the other end is connected to the second inductor L. x One end of the second inductor L is connected to one end of the sixth switch S6, and the other end of the second inductor L is connected to the sixth switch S6. x The other end is connected to the second input / output capacitor C ups One end of the transistor is connected, and the other end of the sixth switch S6 is connected to the first input / output capacitor C. bus The other end, and the second input / output capacitor C ups The other end is connected.

[0039] Based on the above, this circuit structure can achieve a fast dynamic response in both forward Buck and reverse Boost operating modes, that is, a rapid response based on the power demand of the load. It can be understood that since both ends of the circuit are connected to DC power supplies, when the circuit is powered in the forward direction, the second input / output capacitor C... upsThe DC power supply on one side is the load, and when the circuit supplies power in reverse, the first input / output capacitor C... bus The DC power supply on one side is the load.

[0040] Specifically, when the circuit structure is in positive Buck operating mode, i.e., the first input / output capacitor C bus The power supply on one side is connected to the second input / output capacitor C. ups The load on one side is supplied with step-down power.

[0041] At this point, the circuit structure can be as follows: Figure 2 As shown, under operating condition one, the first switch S1 and the second switch S2 are alternately turned on, while the third switch S3 is always off, the fourth switch S4 is always on, the fifth switch S5 is always off, and the sixth switch S6 is always off. The duty cycle of the first switch S1 and the second switch S2 is related to the voltage required by the circuit (the operating voltage required by the load).

[0042] If the load power demand increases, the circuit output current needs to be increased. To address this and ensure a faster response, the circuit can be switched to operating condition two. Figure 3 As shown, the first switch S1 is always on, the second switch S2 is always off, the third switch S3 is always on, the fourth switch S4 is always off, and the fifth switch S5 and the sixth switch S6 are alternately on, and are in a positive Buck working mode.

[0043] Understandably, at this time, the first inductor L i The voltage across the capacitor is the first input / output capacitor C. bus Voltage V on bus The corresponding first inductor L i Current i on Li The rate of change is:

[0044]

[0045] The first inductor L under the original operating condition i The voltage across the first input / output capacitor C bus Voltage V on bus Subtract the second input / output capacitor C ups Voltage V on ups And the first inductor L i Current i on Li The corresponding rate of change is:

[0046]

[0047] Therefore, compared to operating condition one, the current in the circuit under operating condition two, i.e., the current through the first inductor L, is... iThe current flowing through it rises at a faster rate, thus enabling a quicker response to the load's power demands. However, no energy is transferred from the first input / output capacitor C during this process. bus To the second input / output capacitor C ups To prevent the second input / output capacitor C from being transferred during this process. ups Voltage V on ups The change was too drastic, affecting the fifth switch S5, the sixth switch S6, and the second inductor L. x An auxiliary branch is formed so that the first input / output capacitor C bus The second input / output capacitor C can be connected through this auxiliary branch. ups Step-down power supply, suppressing the second input / output capacitor C ups Voltage fluctuations on V ups The voltage is stable.

[0048] Finally, when the first inductor L i Current i on Li When the target value is reached, that is, the amount of current the circuit needs to output to meet the power demand, the circuit can be switched from operating condition two to operating condition one, so that the first inductor L... i Current i on Li Flow to the load.

[0049] If the load power demand decreases, the circuit output current needs to be reduced. To achieve a faster response, the circuit can be switched to operating condition three, such as... Figure 4 As shown, the first switch S1 is always off, the second switch S2 is always on, the third switch S3 is always off, the fourth switch S4 is always on, and the fifth switch S5 and the sixth switch S6 are alternately on, and are in reverse Boost mode.

[0050] Understandably, at this time, the first inductor L i The voltage across is the negative second input / output capacitor C. ups Voltage V on ups The corresponding first inductor L i Current i on Li The rate of change is:

[0051]

[0052] The first inductor L under the original operating condition i The voltage across the first input / output capacitor C bus Voltage V on bus Subtract the second input / output capacitor C ups Voltage V on ups And the first inductor L i Current i on LiThe corresponding rate of change is:

[0053]

[0054] Therefore, compared to operating condition one, the current in the circuit under operating condition two, i.e., the current through the first inductor L, is... i The current flowing through it decreases at a faster rate, thus enabling a quicker response to the load's power demands. However, in the above process, due to the first inductor L... i The energy from the freewheeling current needs to be allocated to the second input / output capacitor C. ups And load, but as the power required by the load decreases, in order to avoid the second input / output capacitor C ups Voltage V on ups The change is too drastic, causing the second input / output capacitor C to... ups Through the fifth switch S5, the sixth switch S6, and the second inductor L x The auxiliary branch formed is the first input / output capacitor C. bus Reverse boost power supply, thereby suppressing the second input / output capacitor C. ups Voltage fluctuations on V ups The voltage is stable.

[0055] Finally, when the first inductor L i Current i on Li When the target value is reached, that is, when the load requires the circuit to output current to meet the power demand, the circuit can switch from operating condition three to operating condition one to prevent the first inductor L from... i Current i on Li Continue to decrease.

[0056] Furthermore, when the circuit structure is in reverse Boost mode, i.e., the second input / output capacitor C... ups The power supply on one side is connected to the first input / output capacitor C. bus The principle of boosting the power supply to the load on one side is basically similar to, but exactly the opposite of, the aforementioned forward Buck mode.

[0057] At this point, the circuit structure is in operating condition one, namely: the first switch S1 is always on, the second switch S2 is always off, the third switch S3 and the fourth switch S4 are alternately on, the fifth switch S5 is always off, and the sixth switch S6 is always off. The duty cycle of the third switch S3 and the fourth switch S4 is related to the voltage required for the circuit output (the operating voltage required by the load).

[0058] If the load power demand increases, the circuit output current needs to be increased. In this case, the circuit can be switched to operating condition two, with the following circuit structure: Figure 4 As shown, but the first inductor L i Current i on LiThe directions are exactly opposite, and the fifth switch S5 and the sixth switch S6 are turned on alternately, and they are in reverse Boost mode.

[0059] Understandably, at this time, the first inductor L i The voltage across the capacitor is the second input / output capacitor C. ups Voltage V on ups The corresponding first inductor L i Current i on Li The rate of change is:

[0060]

[0061] It can speed up the first inductor L i The rising rate of the current flowing through it allows for a faster response to the load's power demands. Furthermore, during this process, the second input / output capacitor C... ups Through the fifth switch S5, the sixth switch S6, and the second inductor L x The resulting auxiliary branch affects the first input / output capacitor C. bus Reverse boost power supply to suppress the first input / output capacitor C bus Voltage fluctuations on V bus The voltage is stable.

[0062] Finally, when the first inductor L i Current i on Li When the target value is reached, that is, the amount of current the circuit needs to output to meet the power demand, the circuit can be switched from operating condition two to operating condition one, so that the first inductor L... i Current i on Li Flow to the load.

[0063] If the load power demand decreases, the circuit output current needs to be reduced. In this case, the circuit can be switched to operating condition three, with the following circuit structure: Figure 3 As shown, but the first inductor L i Current i on Li The directions are exactly opposite, and the fifth switch S5 and the sixth switch S6 are turned on alternately, and are in the positive Buck working mode.

[0064] Understandably, at this time, the first inductor L i The voltage across is the negative first input / output capacitor C. bus Voltage V on bus The corresponding first inductor L i Current i on Li The rate of change is:

[0065]

[0066] It can speed up the first inductor Li The rate of decrease of the current flowing through it allows for a faster response to the load's power demands. Furthermore, during this process, the first input / output capacitor C... bus Through the fifth switch S5, the sixth switch S6, and the second inductor L x The resulting auxiliary branch is the second input / output capacitor C. ups Forward buck power supply, thereby suppressing the first input / output capacitor C bus Voltage fluctuations on V bus The voltage is stable.

[0067] Finally, when the first inductor L i Current i on Li When the target value is reached, that is, when the load requires the circuit to output current to meet the power demand, the circuit can switch from operating condition three to operating condition one to prevent the first inductor L from... i Current i on Li Continue to decrease.

[0068] It should be noted that the operating conditions of the above circuit in forward Buck mode and reverse Boost mode are independent of each other and are not equivalent.

[0069] Therefore, the bidirectional Buck-Boost circuit provided in this embodiment can meet the fast dynamic response in both forward Buck and reverse Boost operating modes to satisfy the power requirements of the load, and can effectively suppress the first input / output capacitance C. bus Second input / output capacitor C ups Voltage fluctuations are controlled to ensure stable and reliable circuit operation.

[0070] Based on the above, such as Figure 5 As shown, to improve UPS utilization, it can actively support the main power grid or other microgrids during idle periods. Correspondingly, the UPS is connected to the second input / output capacitor C in the aforementioned bidirectional Buck-Boost circuit. ups On one side, that is, in parallel with it, and the first input / output capacitor C in the bidirectional Buck-Boost circuit bus One side is connected to the main power grid or a microgrid.

[0071] The UPS can be composed of multiple identical energy storage components connected in series and parallel, or it can be composed of different energy storage components connected in series and parallel. There is no limitation on this. Modifications and refinements made by those skilled in the art to the embodiments of the present invention without departing from the spirit of the present invention still fall within the scope of the invention application patent of the present invention.

[0072] It should be noted that the main grid or microgrid can be rectified into DC power by a rectifier, and the UPS can also be rectified into DC power by a rectifier, thereby completing energy transfer through this bidirectional Buck-Boost circuit.

[0073] In summary, this invention provides a bidirectional Buck-Boost circuit suitable for data centers, which can support rapid dynamic response in both forward Buck and reverse Boost modes to quickly meet changes in load power demand. When applied to power distribution network scenarios, it can effectively improve UPS utilization.

[0074] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A bidirectional Buck-Boost circuit suitable for data centers, characterized in that, include: First input / output capacitor; Second input / output capacitor; The first switching transistor is connected at one end to one end of the first input / output capacitor; The second switching transistor has one end connected to the other end of the first switching transistor, and the other end connected to the other end of the first input / output capacitor and the other end of the second input / output capacitor, respectively. The first inductor has one end connected to the other end of the first switching transistor and one end of the second switching transistor, respectively. The third switching transistor has one end connected to the other end of the first inductor, and the other end connected to the other end of the first input / output capacitor and the other end of the second input / output capacitor, respectively. The fourth switch is connected at one end to the other end of the first inductor and at one end of the third switch, and at the other end to one end of the second input / output capacitor. The fifth switching transistor has one end connected to one end of the first input / output capacitor; The sixth switch is connected at one end to the other end of the fifth switch, and at the other end to the other end of the first input / output capacitor and the other end of the second input / output capacitor, respectively. The second inductor has one end connected to the other end of the fifth switch and one end of the sixth switch, and the other end connected to one end of the second switch.

2. The bidirectional Buck-Boost circuit for data centers according to claim 1, characterized in that, The circuit formed by the fifth switch, the sixth switch, and the second inductor serves as an auxiliary branch between the first input / output capacitor and the second input / output capacitor. Specifically, by adjusting the duty cycle between the fifth and sixth switching transistors, the auxiliary branch is put into Buck or Boost operating mode to suppress voltage fluctuations on the first or second input / output capacitors.

3. The bidirectional Buck-Boost circuit suitable for data centers according to claim 1, characterized in that, The bidirectional Buck-Boost circuit suitable for data centers includes at least a positive Buck operating mode; Specifically, when the bidirectional Buck-Boost circuit suitable for data centers is in the forward Buck operating mode, the power supply on the first input / output capacitor side is used to step down the load on the second input / output capacitor side.

4. The bidirectional Buck-Boost circuit for data centers according to claim 3, characterized in that, When the bidirectional Buck-Boost circuit suitable for data centers is in the forward Buck operating mode, it operates according to the following condition: In operating condition one, the first and second switches are turned on alternately, the third switch is always off, the fourth switch is always on, the fifth switch is always off, and the sixth switch is always off.

5. The bidirectional Buck-Boost circuit for data centers according to claim 4, characterized in that, When the current output of the bidirectional Buck-Boost circuit suitable for data centers needs to be increased, it shall operate according to the following operating condition two: Operating condition 2: The first switch is always on, the second switch is always off, the third switch is always on, the fourth switch is always off, and the fifth and sixth switches are alternately on, so that the voltage on the first inductor is the same as the voltage on the first input / output capacitor, thereby accelerating the rate of increase of the current flowing through the first inductor. The auxiliary branch consisting of the fifth switch, the sixth switch, and the second inductor is in a positive Buck operating mode to charge the second input / output capacitor. When the current flowing through the first inductor reaches the current required by the load for the bidirectional Buck-Boost circuit suitable for data centers to output, the bidirectional Buck-Boost circuit suitable for data centers is controlled to switch from operating condition two to operating condition one, so that the current flowing through the first inductor flows to the load.

6. The bidirectional Buck-Boost circuit for data centers according to claim 4, characterized in that, When the current output of the bidirectional Buck-Boost circuit suitable for data centers needs to be reduced, it operates according to the following condition three: Operating condition 3: The first switch is always off, the second switch is always on, the third switch is always off, the fourth switch is always on, and the fifth and sixth switches are alternately on, so that the voltage on the first inductor is negative than the voltage on the second input / output capacitor, thereby accelerating the rate of decrease of the current flowing through the first inductor. The auxiliary branch consisting of the fifth switch, the sixth switch, and the second inductor is in reverse Boost mode to discharge the second input / output capacitor. When the current flowing through the first inductor reaches the current output required by the load from the bidirectional Buck-Boost circuit suitable for data centers, the bidirectional Buck-Boost circuit suitable for data centers switches from operating condition three to operating condition one to prevent the current flowing through the first inductor from continuing to decrease.

7. The bidirectional Buck-Boost circuit suitable for data centers according to claim 1, characterized in that, The bidirectional Buck-Boost circuit suitable for data centers includes at least a reverse Boost operating mode; Specifically, when the bidirectional Buck-Boost circuit suitable for data centers is in reverse Boost mode, the power supply on the second input / output capacitor side is used to boost the load on the first input / output capacitor side.

8. The bidirectional Buck-Boost circuit for data centers according to claim 7, characterized in that, When the bidirectional Buck-Boost circuit suitable for data centers is in reverse Boost mode, it operates according to the following condition: In operating condition one, the first switch is always on, the second switch is always off, the third and fourth switches are alternately on, the fifth switch is always off, and the sixth switch is always off.

9. The bidirectional Buck-Boost circuit for data centers according to claim 8, characterized in that, When the current output of the bidirectional Buck-Boost circuit suitable for data centers needs to be increased, it shall operate according to the following operating condition two: Operating condition 2: The first switch is always off, the second switch is always on, the third switch is always off, the fourth switch is always on, and the fifth and sixth switches are alternately on, so that the voltage on the first inductor is the same as the voltage on the second input / output capacitor, thereby accelerating the rise rate of the current flowing through the first inductor. The auxiliary branch consisting of the fifth switch, the sixth switch, and the second inductor is in reverse Boost mode to charge the first input / output capacitor. When the current flowing through the first inductor reaches the current required by the load for the bidirectional Buck-Boost circuit suitable for data centers to output, the bidirectional Buck-Boost circuit suitable for data centers is controlled to switch from operating condition two to operating condition one, so that the current flowing through the first inductor flows to the load.

10. The bidirectional Buck-Boost circuit for data centers according to claim 8, characterized in that, When the current output of the bidirectional Buck-Boost circuit suitable for data centers needs to be reduced, it operates according to the following condition three: Operating condition 3: The first switch is always on, the second switch is always off, the third switch is always on, the fourth switch is always off, and the fifth and sixth switches are alternately on, so that the voltage on the first inductor is negative than the voltage on the first input / output capacitor, thereby accelerating the rate of decrease of the current flowing through the first inductor. The auxiliary branch consisting of the fifth switch, the sixth switch, and the second inductor is in a positive Buck operating mode to discharge the first input / output capacitor. When the current flowing through the first inductor reaches the current output required by the load from the bidirectional Buck-Boost circuit suitable for data centers, the bidirectional Buck-Boost circuit suitable for data centers switches from operating condition three to operating condition one to prevent the current flowing through the first inductor from continuing to decrease.

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