Energy storage converter

Abstract

The invention discloses an energy storage converter which comprises a full-bridge converter, an active clamping circuit and a DC-DC converter. A first port of the full-bridge converter is connected with a power grid side, and a second port of the full-bridge converter is connected with a first port of the active clamping circuit; a second port of the active clamping circuit is connected with a first port of the DC-DC converter, and a second port of the DC-DC converter is connected with energy storage equipment; the full-bridge converter is used for rectification when the energy storage converter is in a charging state; inversion is carried out when the energy storage converter is in a discharging state; the active clamping circuit is used for boosting voltage when the energy storage converter is in a charging state; reducing the voltage when the energy storage converter is in a discharging state; the DC-DC converter is used for adjusting the charging voltage when the energy storage converter is in the charging state; and the discharge voltage is adjusted when the energy storage converter is in the discharge state. The energy storage converter structure is beneficial to improving the efficiency of the energy storage converter.

Description

Technical Field

[0001] This invention relates to the field of power electronic control and topology technology, and in particular to an energy storage converter. Background Technology

[0002] Power Conversion System (PCS) is a "bidirectional frequency conversion hub" connecting batteries and the power grid. It can complete AC-DC four-quadrant power conversion in milliseconds. It can also achieve multiple functions such as peak shaving, frequency regulation, voltage regulation, and black start by using grid-connected control algorithms or grid-connected VSG algorithms, high-voltage cascaded topology, and high-frequency power full-bridge. However, with the increasing development of energy storage devices, the efficiency of existing PCS technologies still needs to be improved. Summary of the Invention

[0003] To address the aforementioned issues, this application provides an energy storage converter. Using the energy storage converter of this application can improve the efficiency of the energy storage converter.

[0004] This application provides an energy storage converter, which includes a full-bridge converter, an active clamping circuit, and a DC-DC converter. The first port of the full-bridge converter is connected to the grid side, and the second port of the full-bridge converter is connected to the first port of the active clamping circuit. The second port of the active clamping circuit is connected to the first port of the DC-DC converter, and the second port of the DC-DC converter is connected to the energy storage device. Specifically: the full-bridge converter is used to rectify AC power into DC power when the energy storage converter is charging, and to invert DC power into AC power when the energy storage converter is discharging; the active clamping circuit is used to increase the charging voltage when the energy storage converter is charging, and to decrease the discharging voltage when the energy storage converter is discharging; the DC-DC converter is used to adjust the charging voltage according to a preset ratio when the energy storage converter is charging, and to adjust the discharging voltage according to a preset ratio when the energy storage converter is discharging.

[0005] As can be seen, in this embodiment, the energy storage converter, composed of a full-bridge converter, an active clamping circuit, and a DC-DC converter, achieves bidirectional and efficient energy flow. The introduction of the active clamping circuit effectively manages the voltage in the energy storage converter, widening the system's operating voltage range. Simultaneously, the active clamping circuit raises the charging voltage during charging and lowers the discharging voltage during discharging, enabling the full-bridge converter and DC-DC converter to operate at their highest power voltage conditions, thereby improving the energy storage converter's efficiency.

[0006] In one possible embodiment, the energy storage converter further includes an LCL filter; the first port of the full-bridge converter is connected to the grid side via the LCL filter.

[0007] As can be seen, in this embodiment, the first port of the full-bridge converter is connected to the grid side through an LCL filter. The LCL filter efficiently filters out the high-frequency harmonics of the current between the full-bridge converter and the grid side, thereby improving the current quality of the energy storage converter.

[0008] In one possible embodiment, the full-bridge converter is a full-bridge converter based on SiC-MOSFET power devices.

[0009] In one possible embodiment, the DC-DC converter is a DC-DC converter based on SiC-MOSFET power devices.

[0010] As can be seen from the embodiments of this application, by fully adopting SiC-MOSFET-based power device solutions in both the full-bridge converter and the DC-DC converter, the power density, stability, reliability, and conversion efficiency of the energy storage converter are improved.

[0011] In one possible embodiment, the full-bridge converter is a three-phase full-bridge converter. The first port of the full-bridge converter includes a third port connected to grid side A, a fourth port connected to grid side B, and a fifth port connected to grid side C. The active clamping circuit includes a first active clamping circuit, a second active clamping circuit, and a third active clamping circuit. The second port of the active clamping circuit includes the second port of the first active clamping circuit, the second port of the second active clamping circuit, and the second port of the third active clamping circuit. The DC-DC converter includes a first DC-DC converter, a second DC-DC converter, and a third DC-DC converter. The first port of the DC-DC converter includes... It includes a first port of a first DC-DC converter, a first port of a second DC-DC converter, and a first port of a third DC-DC converter; a second port of a full-bridge converter is connected to a first port of a first active clamping circuit; a second port of a full-bridge converter is connected to a first port of a second active clamping circuit; a second port of a full-bridge converter is connected to a first port of a third active clamping circuit; a second port of the first active clamping circuit is connected to a first port of the first DC-DC converter; a second port of the second active clamping circuit is connected to a first port of the second DC-DC converter; and a second port of the third active clamping circuit is connected to a first port of the third DC-DC converter.

[0012] As can be seen, in this embodiment of the application, by using a three-phase full-bridge converter and matching it with three sets of independent active clamping circuits and DC-DC converters, a three-phase balanced high-frequency energy storage converter system is constructed. In this way, the applicability and flexibility of the energy storage converter can be improved by independently designing and controlling each phase circuit.

[0013] In one possible embodiment, the full-bridge converter includes a first sub-converter corresponding to A, a second sub-converter corresponding to B, and a third sub-converter corresponding to C; the first port of the full-bridge converter includes the first port of the first sub-converter, the first port of the second sub-converter, and the first port of the third sub-converter; the second port of the full-bridge converter includes the second port of the first sub-converter, the second port of the second sub-converter, and the second port of the third sub-converter; the active clamping circuit includes a first active clamping circuit, a second active clamping circuit, and a third active clamping circuit, the first port of the active clamping circuit includes the first port of the first active clamping circuit, the first port of the second active clamping circuit, and the first port of the third active clamping circuit, and the second port of the active clamping circuit includes the second port of the first active clamping circuit, the second port of the second active clamping circuit, and the third active clamping circuit. The second port of the DC-DC converter includes a first DC-DC converter, a second DC-DC converter, and a third DC-DC converter. The first port of the DC-DC converter includes the first port of the first DC-DC converter, the first port of the second DC-DC converter, and the first port of the third DC-DC converter. The second port of the first sub-converter is connected to the first port of the first active clamping circuit. The second port of the second sub-converter is connected to the first port of the second active clamping circuit. The second port of the third sub-converter is connected to the first port of the third active clamping circuit. The second port of the first active clamping circuit is connected to the first port of the first DC-DC converter. The second port of the second active clamping circuit is connected to the first port of the second DC-DC converter. The second port of the third active clamping circuit is connected to the first port of the third DC-DC converter.

[0014] As can be seen, in this embodiment, by decomposing the three-phase full-bridge converter into three independent sub-converter modules and corresponding them one by one with the subsequent active clamping circuit and DC-DC converter, three independent parallel power channels are formed, realizing the high modularity of the three-phase energy storage converter system and improving the system's flexibility and maintainability.

[0015] In one possible embodiment, each of the first, second, and third active clamping circuits includes an inductor, a capacitor, and an active clamping power switch; a first port of the active clamping circuit includes a first port of the corresponding inductor; a second port of the inductor is connected to a first port of the capacitor; a second port of the capacitor is connected to the source of the active clamping power switch; a second port of the active clamping circuit includes a second port of the inductor and a drain of the active clamping power switch, wherein the active clamping power switch is used to control the active clamping circuit to raise the charging voltage when the energy storage converter is in a charging state and to lower the discharging voltage when the energy storage converter is in a discharging state.

[0016] As can be seen, in this embodiment of the application, by adopting a circuit topology composed of inductors, capacitors and active clamping power switches, flexible and efficient voltage management is achieved, thereby enabling the full-bridge converter and DC-DC converter to operate under the voltage conditions with the highest efficiency, thus improving the overall efficiency of the energy storage converter.

[0017] In one possible embodiment, each of the first, second, and third DC-DC converters includes a primary-side high-frequency H-bridge converter, a high-frequency transformer, and a secondary-side high-frequency H-bridge converter; the first port of the primary-side high-frequency H-bridge converter is connected to an active clamping circuit, and the second port of the primary-side high-frequency H-bridge converter is connected to the first port of the high-frequency transformer; the second port of the high-frequency transformer is connected to the first port of the secondary-side high-frequency H-bridge converter, and the second port of the secondary-side high-frequency H-bridge converter is connected to an energy storage device.

[0018] As can be seen, in this embodiment of the application, by adopting a topology consisting of two H-bridges and a high-frequency transformer in each DC-DC conversion channel, bidirectional energy flow and electrical isolation between input and output are achieved.

[0019] In one possible embodiment, the primary-side high-frequency H-bridge converter further includes a first power switch, a second power switch, a third power switch, and a fourth power switch; the first port of the primary-side high-frequency H-bridge converter includes the drain of the first power switch, the source of the second power switch, the drain of the third power switch, and the source of the fourth power switch; the second port of the primary-side high-frequency H-bridge converter includes the source of the first power switch, the drain of the second power switch, the source of the third power switch, and the drain of the fourth power switch.

[0020] In one possible embodiment, the active clamping power switch is further configured to: disconnect when the first power switch and the third power switch are simultaneously closed; close when the first power switch and the third power switch are simultaneously open; disconnect when the first power switch is open and the third power switch is closed; and close when the first power switch is closed and the third power switch is open.

[0021] As can be seen, in this embodiment of the application, by setting the interlocking and complementary drive timing between the active clamp power switch and the specific switch of the H-bridge, the active clamp circuit and the subsequent DC-DC converter work together to realize the function of raising the charging voltage during charging and lowering the discharging voltage during discharging, thereby improving the working efficiency of the energy storage converter. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the structure of an energy storage converter provided in an embodiment of this application; Figure 2 A schematic diagram of another energy storage converter provided in the embodiments of this application; Figure 3 A circuit structure diagram of an energy storage converter provided in an embodiment of this application; Figure 4 A control block diagram of a full-bridge converter in rectification mode provided in an embodiment of this application; Figure 5 A theoretical block diagram illustrating the control of charging an energy storage device according to an embodiment of this application; Figure 6 The theoretical block diagram of the discharge control of an energy storage device provided in the embodiments of this application is as follows: The theoretical derivation of the discharge process is as follows; Figure 7 This application provides a schematic diagram of the steady-state waveform of an energy device in discharge mode, as shown in the embodiments of the present application. Figure 8 A control block diagram of a full-bridge converter in inverter mode provided in this application embodiment; Figure 9 A schematic diagram of the circuit structure of another energy storage converter provided in an embodiment of this application. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0025] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0026] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0027] The embodiments of this application will now be described with reference to the accompanying drawings.

[0028] Example 1: Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of an energy storage converter provided in an embodiment of this application is shown below. Figure 1 The energy storage converter 100 shown includes a full-bridge converter 101, an active clamping circuit 102, and a DC-DC converter 103.

[0029] The first port of the full-bridge converter 101 is connected to the grid side, and the second port of the full-bridge converter 101 is connected to the first port of the active clamping circuit 102; the second port of the active clamping circuit 102 is connected to the first port of the DC-DC converter 103, and the second port of the DC-DC converter 103 is connected to the energy storage device.

[0030] In this embodiment, the full-bridge converter 101 is used to rectify AC power into DC power when the energy storage converter 100 is in a charging state, and to invert DC power into AC power when the energy storage converter 100 is in a discharging state.

[0031] Specifically, the full-bridge converter 101 serves as the grid-side interface, responsible for AC-DC conversion. In charging mode, it rectifies the AC power from the grid into DC power; in discharging mode, it inverts the DC power from the downstream stage into AC power and feeds it into the grid.

[0032] The active clamping circuit 102 is used to raise the charging voltage when the energy storage converter 100 is in the charging state and to lower the discharge voltage when the energy storage converter 100 is in the discharging state.

[0033] Specifically, the active clamping circuit 102 is connected between the full-bridge converter 101 and the DC-DC converter 103, and its core function is voltage regulation. In the charging state, by controlling its internal components, this circuit can raise the charging voltage from the full-bridge converter 101 to provide a suitable input voltage for the subsequent DC-DC converter 103. In the discharging state, it lowers the discharging voltage from the DC-DC converter 103 to meet the needs of the full-bridge converter 101.

[0034] DC-DC converter 103 is used to adjust the charging voltage according to a preset ratio when the energy storage converter 100 is in the charging state; and to adjust the discharging voltage according to a preset ratio when the energy storage converter is in the discharging state.

[0035] Specifically, the DC-DC converter 103 serves as the interface on the energy storage device side, primarily responsible for voltage isolation and precise conversion. In charging mode, it adjusts the voltage according to a preset transformation ratio to provide the energy storage device with suitable charging voltage and current. In discharging mode, it adjusts the output voltage of the energy storage device according to the preset transformation ratio to meet the requirements of grid-connected inverters.

[0036] Furthermore, the interface between the DC-DC converter 103 and the energy storage device includes one or more interfaces to adapt to one or more energy storage devices or V2G (Vehicle to Grid, V2G) type energy storage devices.

[0037] As can be seen, in this embodiment, the energy storage converter, composed of a full-bridge converter, an active clamping circuit, and a DC-DC converter, achieves bidirectional and efficient energy flow. The introduction of the active clamping circuit effectively manages the voltage in the energy storage converter, widening the system's operating voltage range. Simultaneously, the active clamping circuit raises the charging voltage during charging and lowers the discharging voltage during discharging, enabling the full-bridge converter and DC-DC converter to operate at their highest power voltage conditions, thereby improving the energy storage converter's efficiency.

[0038] Optionally, the energy storage converter also includes an LCL filter; the first port of the full-bridge converter is connected to the grid side via the LCL filter.

[0039] Specifically, the energy storage converter also includes an LCL filter. The first port of the full-bridge converter is connected to the grid side through the LCL filter. The LCL filter efficiently filters out high-frequency harmonics of the current between the full-bridge converter and the grid side, thereby improving the current quality of the energy storage converter.

[0040] Optionally, the full-bridge converter is a full-bridge converter based on SiC-MOSFET power devices.

[0041] Optionally, the DC-DC converter is a DC-DC converter based on SiC-MOSFET power devices.

[0042] The full-bridge converter, as the core of AC-DC conversion, uses SiC-MOSFET power devices (such as the switches that make up the three-phase full bridge or each sub-converter) as its internal power switches. Similarly, in the DC-DC converter, whether it is the primary-side high-frequency H-bridge converter or the secondary-side high-frequency H-bridge converter, the power switches also use SiC-MOSFETs.

[0043] The choice of SiC-MOSFET as the core power device is mainly based on the system performance improvement brought about by its excellent material properties.

[0044] Firstly, SiC-MOSFET power devices exhibit extremely low switching losses and excellent reverse recovery characteristics, allowing the system to operate at higher switching frequencies. This enables the aforementioned passive components such as high-frequency transformers and LCL filters to be designed to be smaller and lighter, directly contributing to the realization of high power density and miniaturization of energy storage converters.

[0045] Secondly, SiC-MOSFET power devices have higher junction temperature tolerance, which improves the thermal stability and reliability of the system, or allows for greater power output under the same heat dissipation conditions.

[0046] Furthermore, SiC-MOSFET power devices exhibit lower on-state resistance and switching losses compared to silicon-based IGBTs of equivalent specifications, with a more pronounced efficiency advantage, especially in high-frequency applications. This directly improves the overall conversion efficiency of the energy storage converter during charge-discharge cycles.

[0047] As can be seen from the embodiments of this application, by fully adopting SiC-MOSFET-based power device solutions in both the full-bridge converter and the DC-DC converter, the power density, stability, reliability, and conversion efficiency of the energy storage converter are improved.

[0048] Optionally, the full-bridge converter is a three-phase full-bridge converter. The first port of the full-bridge converter includes a third port connected to grid side A, a fourth port connected to grid side B, and a fifth port connected to grid side C. The active clamping circuit includes a first active clamping circuit, a second active clamping circuit, and a third active clamping circuit. The second port of the active clamping circuit includes the second port of the first active clamping circuit, the second port of the second active clamping circuit, and the second port of the third active clamping circuit. The DC-DC converter includes a first DC-DC converter, a second DC-DC converter, and a third DC-DC converter. The first port of the DC-DC converter includes a first... The first port of the DC-DC converter, the first port of the second DC-DC converter, and the first port of the third DC-DC converter; the second port of the full-bridge converter is connected to the first port of the first active clamping circuit; the second port of the full-bridge converter is connected to the first port of the second active clamping circuit; the second port of the full-bridge converter is connected to the first port of the third active clamping circuit; the second port of the first active clamping circuit is connected to the first port of the first DC-DC converter; the second port of the second active clamping circuit is connected to the first port of the second DC-DC converter; the second port of the third active clamping circuit is connected to the first port of the third DC-DC converter.

[0049] Specifically, in the embodiments of this application, the specific connection relationships of the three-phase system architecture are explained.

[0050] When the full-bridge converter is a three-phase full-bridge converter, its first port (i.e., the AC side connected to the power grid) has three independent ports, corresponding to phases A, B, and C respectively. To match this three-phase structure, the active clamping circuit and the DC-DC converter are also set as three independent units, namely the first, second, and third active clamping circuits, and the first, second, and third DC-DC converters.

[0051] The specific connection method is as follows: the second port of the full-bridge converter is connected to the first port of the first active clamping circuit; the second port of the full-bridge converter is connected to the first port of the second active clamping circuit; the second port of the full-bridge converter is connected to the first port of the third active clamping circuit; the second port of the first active clamping circuit is connected to the first port of the first DC-DC converter; the second port of the second active clamping circuit is connected to the first port of the second DC-DC converter; and the second port of the third active clamping circuit is connected to the first port of the third DC-DC converter.

[0052] In this architecture, the three-phase circuits can be controlled independently. For example, in terms of control strategy, the first DC-DC converter (corresponding to phase A) can be in phase with the triangular carrier wave of the three-phase full-bridge converter, the triangular carrier wave of the second DC-DC converter (corresponding to phase B) can be lagging behind the triangular carrier wave of the first DC-DC converter by 120°, and the triangular carrier wave of the third DC-DC converter (corresponding to phase C) can be further lagging behind the triangular carrier wave of the second DC-DC converter by 120°. This phase-shift control helps to smooth the total DC-side current and reduce current ripple and electromagnetic interference.

[0053] As can be seen, in this embodiment of the application, by using a three-phase full-bridge converter and matching it with three sets of independent active clamping circuits and DC-DC converters, a three-phase balanced high-frequency energy storage converter system is constructed. In this way, the applicability and flexibility of the energy storage converter can be improved by independently designing and controlling each phase circuit.

[0054] Example 2: The above-described embodiments mainly depict an energy storage converter based on a three-phase full-bridge converter. Based on the premise that the full-bridge converter includes three sub-converters corresponding to the three phases, this embodiment also provides a more detailed energy storage converter. Please refer to... Figure 2 , Figure 2 This is a schematic diagram of another energy storage converter provided in an embodiment of this application.

[0055] like Figure 2 The energy storage converter 100 shown includes a full-bridge converter 101 (not shown in the figure). The full-bridge converter 101 includes a first sub-converter 1011 corresponding to A, a second sub-converter 1012 corresponding to B, and a third sub-converter 1013 corresponding to C. The first port of the full-bridge converter 101 includes the first port of the first sub-converter 1011, the first port of the second sub-converter 1012, and the first port of the third sub-converter 1013. The second port of the full-bridge converter 101 includes the second port of the first sub-converter 1011, the second port of the second sub-converter 1012, and the second port of the third sub-converter 1013.

[0056] The active clamping circuit 102 (not shown in the figure) includes a first active clamping circuit 1021, a second active clamping circuit 1022, and a third active clamping circuit 1023; the first port of the active clamping circuit 102 includes the first port of the first active clamping circuit 1021, the first port of the second active clamping circuit 1022, and the first port of the third active clamping circuit 1023; the second port of the active clamping circuit 102 includes the second port of the first active clamping circuit 1021, the second port of the second active clamping circuit 1022, and the second port of the third active clamping circuit 1023.

[0057] The DC-DC converter 103 (not shown in the figure) includes a first DC-DC converter 1031, a second DC-DC converter 1032, and a third DC-DC converter 1033. The first port of the DC-DC converter 103 includes the first port of the first DC-DC converter 1031, the first port of the second DC-DC converter 1032, and the first port of the third DC-DC converter 1033.

[0058] Specifically, the second port of the first sub-converter 1011 is connected to the first port of the first active clamping circuit 1021; the second port of the second sub-converter 1012 is connected to the first port of the second active clamping circuit 1022; the second port of the third sub-converter 1013 is connected to the first port of the third active clamping circuit 1023; the second port of the first active clamping circuit 1021 is connected to the first port of the first DC-DC converter 1031; the second port of the second active clamping circuit 1022 is connected to the first port of the second DC-DC converter 1032; and the second port of the third active clamping circuit 1023 is connected to the first port of the third DC-DC converter 1033.

[0059] Specifically, in this embodiment, the full-bridge converter 100 is structurally divided into three independent power modules: a first sub-converter 1011, a second sub-converter 1012, and a third sub-converter 1013, corresponding to phases A, B, and C, respectively. Each sub-converter is essentially a complete single-phase full-bridge or half-bridge converter unit. Its first port (AC side) together constitutes the first port of the full-bridge converter 101, which is used to connect to the grid side (through an LCL filter); its second port (DC side) together constitutes the second port of the full-bridge converter 101.

[0060] To match this distributed architecture, the active clamp circuit 102 and the DC-DC converter 103 are also configured as three independent, identical units. The DC-side output of each sub-converter is independently connected to a corresponding active clamp circuit (e.g., the first sub-converter 1011 is connected to the first active clamp circuit 1021), and the output of each active clamp circuit is then independently connected to a corresponding DC-DC converter 103 (e.g., the first active clamp circuit 1021 is connected to the first DC-DC converter 1031). This creates three completely independent and symmetrical single-phase power processing channels: Phase A channel (including the first sub-converter 1011, the first active clamping circuit 1021, and the first DC-DC converter 1031), Phase B channel (including the second sub-converter 1012, the second active clamping circuit 1022, and the second DC-DC converter 1032), and Phase C channel (including the third sub-converter 1013, the third active clamping circuit 1023, and the third DC-DC converter 1033).

[0061] In this architecture, the three-phase system is completely decoupled on the DC side. In terms of control, independent voltage or current control can be implemented for the three channels. Simultaneously, to optimize system performance, carrier phase-shifting technology can still be used. For example, the carrier signal controlling the first DC-DC converter 1031 can be delayed by 120° sequentially from the carrier signals controlling the second DC-DC converter 1032 and the third DC-DC converter 1033, thereby effectively reducing the total current ripple of the DC bus.

[0062] In addition, a buffer inductor or LC filter is also included between the grid side and the first sub-converter 1011, the second sub-converter 1012 and the third sub-converter 1013.

[0063] As can be seen, in this embodiment, by decomposing the three-phase full-bridge converter into three independent sub-converter modules and corresponding them one by one with the subsequent active clamping circuit and DC-DC converter, three independent parallel power channels are formed, realizing the high modularity of the three-phase energy storage converter system and improving the system's flexibility and maintainability.

[0064] Example 3: The above-mentioned application examples mainly describe energy storage converters with different full-bridge converters. Based on this, this application example mainly describes active clamping circuits and DC-DC converters. For relevant descriptions of the full-bridge converter in this application example, please refer to the foregoing related content; they will not be repeated here.

[0065] Optionally, each of the first, second, and third active clamping circuits includes an inductor, a capacitor, and an active clamping power switch. The first port of the active clamping circuit includes the first port of the corresponding inductor. The second port of the inductor is connected to the first port of the capacitor. The second port of the capacitor is connected to the source of the active clamping power switch. The second port of the active clamping circuit includes the second port of the inductor and the drain of the active clamping power switch, wherein the active clamping power switch controls the active clamping circuit to raise the charging voltage when the energy storage converter is charging and to lower the discharging voltage when the energy storage converter is discharging.

[0066] In this application embodiment, the specific structure and working mechanism of the active clamping circuit are explained. The active clamping circuit includes three core components: an inductor, a capacitor, and an active clamping power switch.

[0067] It should be noted that the second port of the specific full-bridge converter includes a positive port and a negative port. The positive port of the full-bridge converter is connected in parallel to the first port of the inductor in each of the three active clamping circuits. The second port of the inductor is connected in parallel to the first port of the corresponding capacitor and the corresponding DC-DC converter. The other end of the capacitor is connected to the source of the active clamping power switch, and the drains of the power switches in the three active clamping circuits are connected in parallel to the negative port of the full-bridge converter.

[0068] When the energy storage converter is in charging mode, the circuit enters boost mode by precisely controlling the switching timing of the active clamping power switch. During this process, the inductor stores and releases energy, working in conjunction with the capacitor to raise the DC bus voltage from the full-bridge converter, providing a sufficiently high input voltage to the subsequent DC-DC converter and ensuring effective charging of the energy storage device.

[0069] When the energy storage converter is in the discharge state, the active clamping power switch is controlled to operate in the opposite phase. At this time, the circuit operates in buck mode, which can clamp and reduce the higher voltage from the energy storage device side after being boosted by the DC-DC converter, in order to meet the DC-side voltage requirements of the full-bridge converter and achieve stable grid connection.

[0070] As can be seen, in this embodiment of the application, by adopting a circuit topology composed of inductors, capacitors and active clamping power switches, flexible and efficient voltage management is achieved, thereby enabling the full-bridge converter and DC-DC converter to operate under the voltage conditions with the highest efficiency, thus improving the overall efficiency of the energy storage converter.

[0071] Optionally, each of the first, second, and third DC-DC converters includes a primary-side high-frequency H-bridge converter, a high-frequency transformer, and a secondary-side high-frequency H-bridge converter; the first port of the primary-side high-frequency H-bridge converter is connected to an active clamping circuit, and the second port of the primary-side high-frequency H-bridge converter is connected to the first port of the high-frequency transformer; the second port of the high-frequency transformer is connected to the first port of the secondary-side high-frequency H-bridge converter, and the second port of the secondary-side high-frequency H-bridge converter is connected to an energy storage device.

[0072] Specifically, in the embodiments of this application, the specific structure and function of the DC-DC converter are explained. The following applies to any one of the first DC-DC converter, the second DC-DC converter, and the third DC-DC converter described above.

[0073] Each DC-DC converter unit mainly consists of three parts: a primary-side high-frequency H-bridge converter, a high-frequency transformer, and a secondary-side high-frequency H-bridge converter. These three parts are connected in sequence to form a complete DC-DC conversion channel.

[0074] The primary-side high-frequency H-bridge converter serves as the input terminal. Its first port is connected to the output of the preceding active clamping circuit, receiving the DC voltage processed by the clamping circuit. Its second port is connected to the primary winding of the high-frequency transformer. This H-bridge converter typically consists of multiple power switches. By controlling the on and off states of these switches, the DC power is inverted into high-frequency AC power and applied to the primary winding of the high-frequency transformer.

[0075] High-frequency transformers are core components for achieving electrical isolation and voltage transformation. Their turns ratio can be designed according to system requirements. On the one hand, they electrically isolate the primary and secondary sides, improving system safety; on the other hand, they transmit the high-frequency AC voltage from the primary side to the secondary side according to the turns ratio.

[0076] The secondary-side high-frequency H-bridge converter is connected between the secondary winding of the high-frequency transformer and the energy storage device (such as a battery pack). It also consists of multiple power switching transistors. The operating mode of this H-bridge dynamically switches depending on whether the system is in a charging or discharging state.

[0077] In charging mode, the secondary H-bridge operates in synchronous rectification mode, rectifying the high-frequency AC power from the transformer secondary side into DC power to charge the energy storage device. In discharging mode, the secondary H-bridge operates in high-frequency inverter mode, inverting the DC power supplied by the energy storage device into high-frequency AC power, which is then transmitted to the primary side through the transformer.

[0078] As can be seen, in this embodiment of the application, by adopting a topology consisting of two H-bridges and a high-frequency transformer in each DC-DC conversion channel, bidirectional energy flow and electrical isolation between input and output are achieved.

[0079] Optionally, the primary-side high-frequency H-bridge converter further includes a first power switch, a second power switch, a third power switch, and a fourth power switch; the first port of the primary-side high-frequency H-bridge converter includes the drain of the first power switch, the source of the second power switch, the drain of the third power switch, and the source of the fourth power switch; the second port of the primary-side high-frequency H-bridge converter includes the source of the first power switch, the drain of the second power switch, the source of the third power switch, and the drain of the fourth power switch.

[0080] Specifically, in the embodiments of this application, the specific topology and port definitions of the primary-side high-frequency H-bridge converter are explained.

[0081] The primary-side high-frequency H-bridge converter adopts a classic H-bridge full-bridge structure, consisting of four power switches, designated as the first to fourth power switches. It should be noted that the drains of the first and third power switches are connected to the second port of the inductor in the corresponding active clamping circuit.

[0082] The drains of the second and fourth power switches are connected to the second port of the full-bridge converter.

[0083] During operation, by controlling the turn-on and turn-off timing of these four power switches (for example, controlling the first and fourth power switches to turn on simultaneously, or the second and third power switches to turn on simultaneously), a high-frequency alternating positive and negative AC voltage can be generated on the primary side of the high-frequency transformer.

[0084] Specific control strategies may include phase-shift control, where the triangular carriers of the first and fourth power switches have a phase shift angle δ with the triangular carriers of the second and third power switches; the first power switch is complementary to the second power switch, and the third power switch is complementary to the fourth power switch.

[0085] Optionally, the active clamping power switch is also used to disconnect when the first power switch and the third power switch are closed, and to close when the first power switch and the third power switch are open.

[0086] Specifically, in the embodiments of this application, the collaborative control logic between the active clamp power switch and the primary-side H-bridge power switch is further explained.

[0087] This control logic defines the mutual exclusion relationship between the clamping switch in the active clamping circuit and the drive signals of two specific switches in the primary-side high-frequency H-bridge converter.

[0088] This mutual exclusion relationship is specifically manifested as follows: when the first power switch and the third power switch are closed (conducted) at the same time, the active clamping power switch is controlled to be open (turned off).

[0089] When the first power switch and the third power switch are simultaneously turned off, the active clamping power switch is controlled to be closed (conducted).

[0090] When the first power switch is turned off and the third power switch is turned on, the active clamping power switch is controlled to be turned off.

[0091] When the first power switch is closed (on) and the third power switch is open (off), the active clamping power switch is controlled to be closed (on).

[0092] This control relationship manifests as an "XOR" logic characteristic in the circuit's operating waveform. Its core physical significance lies in the fact that, through precise timing coordination, the clamping switch is turned on during the dead time when the diagonal switches of the H-bridge are not conducting, providing a path for the inductor's freewheeling current. At the same time, the clamping capacitor absorbs the inductor's energy, thereby effectively clamping and utilizing the voltage spikes during the switching process.

[0093] As can be seen, in this embodiment of the application, by setting the interlocking and complementary drive timing between the active clamp power switch and the specific switch of the H-bridge, the active clamp circuit and the subsequent DC-DC converter work together to realize the function of raising the charging voltage during charging and lowering the discharging voltage during discharging, thereby improving the working efficiency of the energy storage converter.

[0094] For example, please see Figure 3 , Figure 3 This application provides a schematic diagram of the circuit structure of an energy storage converter, wherein the LCL filter is connected to the power grid on the grid side. u A , u B and u C Filter common point connection u n The LCL filter is connected to the A, B, and C terminals of the full-bridge converter, respectively. The full-bridge converter is the structure shown in Example 1.

[0095] The inductors of the first, second, and third active clamping circuits are connected in parallel to the positive terminal of the DC side of the full-bridge converter. L B1 , L B2 and L B3 The negative terminals of the DC side of the three-phase full-bridge converter are connected in parallel to the negative terminals (other side) of the first, second, and third DC-DC converters, respectively.

[0096] The following description uses the first active clamping circuit and the first DC-DC converter as examples. For the internal structure of other active clamping circuits and DC-DC converters, please refer to the relevant description in the first section, which will not be repeated here. The first active clamping circuit includes an inductor. L B1 ,capacitance C c1 ,capacitance C cc1 ,diode D cc1 and active clamping power switch T cc1 The remaining components belong to the first DC-DC converter.

[0097] Inductors in the first active clamping circuit and the first DC-DC converter L B1 One side is connected to the positive DC terminal of the three-phase full-bridge converter, and the other side is connected to a capacitor. Cc1 One side is connected to the power switch of the H-bridge converter. T H1_1 and T H1_3 The drain of the power switch transistor T H1_1 The source is connected to the high-frequency transformer. v H1_p1 Side-connected power switching transistor T H1_2 The drain of the power switch transistor T H1_2 The source is connected to the negative DC side of the three-phase full-bridge converter, and the power switch transistor... T H1_3 The source is connected to the high-frequency transformer. v H1_p2 Side-connected power switching transistor T H1_4 The drain of the power switch transistor T H1_4 The source terminal is connected to the negative terminal of the DC side of the three-phase full-bridge converter; the capacitor C C1 The other side is connected to an active clamping power switch. T CC1 The source of the active clamping power switch transistor. T CC1 The drain of the circuit is connected to the negative terminal of the DC side of the three-phase full-bridge converter.

[0098] The high-frequency transformer of the first DC-DC converter v H1_s1 Side-connected power switching transistor T H1_5 Source and power switch T H1_6 The drain of the power switch transistor T H1_5 Drain and power switch T H1_7 The drain of the power switch is connected to the positive terminal of the energy storage device. T H1_6 The source and power switch T H1_8 The source terminal is connected to the negative terminal of the energy storage device, and the high-frequency transformer... v H1_s2 Side-connected power switching transistor T H1_8 drain and power switching transistor T H1_7 The source pole.

[0099] First, if the energy storage converter is in a charging state, such as Figure 3The energy storage converter control shown includes the following steps: (1) The three-phase full-bridge converter rectifies the AC voltage in a fully controlled manner to obtain the DC voltage. V dc .

[0100] Specifically, please see Figure 4 , Figure 4 A control block diagram of a full-bridge converter in rectification mode provided in this application embodiment, such as... Figure 4 As shown, the theoretical derivation of the control process of the full-bridge converter is given by the following formula, where the Park positive transform is shown in equation (1): (1) in, u A , u B and u C These are the three-phase AC voltages on the grid side. u sd_rec , u sq_rec and u 0_rec These represent the voltage d, q, and the 0-axis reference value obtained after the Park transformation. T abc / dq0 This is the Park positive transformation matrix.

[0101] The capacitor voltage regulation control is shown in equation (2) below: (2) in, u dc , u dc _r ef , i sd_rec_ref , K p1 , K i1 These are the real-time feedback value of capacitor voltage, the reference value of capacitor voltage, the reference value of d-axis current, the proportional coefficient of DC voltage control loop, and the integral coefficient of DC voltage control loop, respectively.

[0102] The transformation of the rectified current park is shown in equation (3): (3) in, i A , i B and i C These are the three-phase AC voltages on the grid side.i sd_rec , i sq_rec and i 0_rec These represent the current d, q, and the 0-axis reference value obtained after the Park transformation. T abc / dq0 This is the Park positive transformation matrix.

[0103] The reactive power control is shown in equation (4) below: (4) In the formula, i sq_rec_ref , K p2 , K i2 These are the reactive reference current, the proportional coefficient of the current decoupling control loop, and the integral coefficient of the current decoupling control loop, respectively. u sq_rec_ref , X LCL These represent the q-axis reference voltage value and the LCL filter impedance coefficient, respectively.

[0104] The active power control is shown in equation (5): (5) In the formula, i sd_rec_ref , K p2 , K i2 These are the active reference current, the proportional coefficient of the current decoupling control loop, and the integral coefficient of the current decoupling control loop, respectively. u sd_rec_ref , X LCL These represent the d-axis reference voltage value and the LCL filter impedance coefficient, respectively.

[0105] The inverse park transform is shown in equation (6): (6) In the formula, u A_rec_ref , u B_rec_ref ,and u C_rec_ref These are the reference values ​​of the three voltages A, B, and C obtained after the inverse Park transformation, respectively, and Tdq0 / abc is the Park inverse-forward transformation matrix.

[0106] Will u A_rec_ref , u B_rec_ref , uC_rec_ref The high-frequency carrier is provided to the PWM drive signal of all the switching transistors of the three-phase full-bridge converter operating in rectification mode, which is controlled by the SVPWM modulation strategy.

[0107] (2) The high-frequency inverter of the primary side H-bridge of the DC-DC converter generates a high-frequency alternating voltage. The transformer isolates and transforms the high-frequency alternating voltage and transmits it to the secondary side H-bridge rectifier.

[0108] (3) The secondary H-bridge rectifier and the primary H-bridge inverter are synchronously controlled to achieve synchronous rectification.

[0109] (4) Adjust the duty cycle d of the power switching device of the primary H-bridge inverter in real time according to the charging demand of the energy storage device to realize real-time control of the charging power.

[0110] Specifically, please see Figure 5 , Figure 5 The theoretical block diagram for the control of charging of an energy storage device provided in the embodiments of this application is shown in the following equation (7): (7) In the formula, V BAT_charge_ref , V BAT , K p4 , K i4 , I BAT_charge_ref , I BAT , K p5 , K i5 , d These are, respectively, the reference rated voltage of the energy storage device, the actual real-time voltage feedback value of the energy storage device, the proportional coefficient of the charging voltage control loop of the energy storage device, the integral coefficient of the charging voltage control loop of the energy storage device, the reference current of the energy storage device, the actual real-time current feedback value of the energy storage device, the proportional coefficient of the charging current control loop of the energy storage device, the integral coefficient of the charging current control loop of the energy storage device, and the duty cycle.

[0111] duty cycle d The high-frequency carrier is given to the PWM modulation control to obtain the PWM drive signal for the corresponding power switching device.

[0112] If the energy storage converter is in a discharging state, such as Figure 3 The control method for the energy storage converter shown includes the following steps: (1) Voltage of energy storage equipment V BATThe high-frequency alternating voltage is generated by the high-frequency inverter on the secondary side of the DC-DC converter. The transformer isolates and transforms the high-frequency alternating voltage and transmits it to the primary side H-bridge rectifier.

[0113] Please see Figure 6 , Figure 6 The theoretical block diagram of discharge control for an energy storage device provided in this application embodiment is as follows. The theoretical derivation of the discharge process is based on the following: Figure 6 The control logic shown below contains the relevant parameters for the discharge of the energy storage device, as shown in equation (8): (8) In the formula, V BAT_discharge_ref , V BAT , K p6 , K i6 , I BAT_discharge_ref , I BAT , K p7 , K i7 , d sum These are, respectively, the minimum reference voltage for energy storage device discharge, the actual real-time voltage feedback value of the energy storage device, the proportional coefficient of the energy storage device discharge voltage control loop, the integral coefficient of the energy storage device discharge voltage control loop, the reference current of the energy storage device, the actual real-time current feedback value of the energy storage device, the proportional coefficient of the energy storage device discharge current control loop, the integral coefficient of the energy storage device discharge current control loop, and the duty cycle. d sum The high-frequency carrier is given to the PWM modulation control to obtain the PWM drive signal for the power switching device in the DC-DC converter.

[0114] (2) The primary H-bridge rectifier and the secondary H-bridge inverter are synchronously controlled to achieve synchronous rectification.

[0115] Specifically, please see Figure 7 , Figure 7 This application provides a schematic diagram of the steady-state waveform of an energy storage device in discharge mode, as shown in the embodiment. The key waveforms of the active clamping circuit and the subsequent DC-DC converter operating in the steady-state state of the energy storage device in discharge mode are as follows: Figure 7 As shown.

[0116] (3) The three-phase full-bridge converter converts DC voltage V dc The inverter outputs a three-phase AC voltage after passing through an LCL filter. Please see Figure 8 , Figure 8This application provides a control block diagram of a full-bridge converter in inverter mode. For the control logic of the full-bridge converter when it is operating in inverter mode, please refer to the relevant descriptions of equations (1) to (6), which will not be repeated here.

[0117] (4) Adjust the phase shift angle β of the power switching device of the secondary H-bridge inverter of the DC-DC converter in real time according to the three-phase power output demand to realize the real-time control of the discharge power.

[0118] For example, please see Figure 9 , Figure 9 A schematic diagram of another energy storage converter provided in the embodiments of this application is shown below. Figure 9 The full-bridge converter of the energy storage converter shown is the structure shown in Embodiment 2, which includes multiple sub-converters.

[0119] Among them, the positive DC-side terminal of the first sub-converter is connected to the inductor of the first active clamping circuit. L B1 Connections: The negative DC-side terminal of the first sub-converter is connected to the negative terminal of the first DC-DC converter. For the internal structures of the sub-converters, as well as the internal structures of the second and third sub-converters, please refer to the relevant description of the first sub-converter. Figure 9 The connection relationships shown will not be elaborated here.

[0120] In addition, please refer to the description of the active clamping circuit of the energy storage converter, the DC-DC converter, and their specific operating logic in the example. Figure 3 The relevant details will not be elaborated here.

[0121] Through the energy storage converters described in the above embodiments, it can be seen that the active clamping circuit improves the operating efficiency of the energy storage converter; the SiC-MOSFET-based power devices improve the power density, stability, reliability, and conversion efficiency of the energy storage converter; the LCL filter improves the current quality of the energy storage converter; the three-phase full-bridge converter improves the system's modularity, thereby enhancing flexibility and maintainability; and the circuit topology of the active clamping circuit and the DC-DC converter enhances the overall efficiency of the energy storage converter. The interlocking and complementary drive timing between the active clamping power switches and the specific switches of the H-bridge further improves the operating efficiency of the energy storage converter.

[0122] Those skilled in the art will appreciate that the functionality described in conjunction with the various illustrative logic blocks, modules, and algorithmic steps disclosed herein can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality described by the various illustrative logic blocks, modules, and steps can be stored or transmitted as one or more instructions or codes on a computer-readable medium and executed by a hardware-based processing unit. The computer-readable medium may comprise a computer-readable storage medium, which corresponds to a tangible medium, such as a data storage medium, or a communication medium that includes any medium facilitating the transfer of a computer program from one place to another (e.g., based on a communication protocol). In this way, the computer-readable medium may substantially correspond to (1) a non-transitory tangible computer-readable storage medium, or (2) a communication medium, such as a signal or carrier wave. The data storage medium may be any available medium accessible by one or more computers or one or more processors to retrieve instructions, code, and / or data structures for implementing the techniques described in this application. A computer program product may comprise a computer-readable medium.

[0123] By way of example and not limitation, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage devices, magnetic disk storage devices or other magnetic storage devices, flash memory, or any other media that can be used to store desired program code in the form of instructions or data structures and is accessible by a computer. Furthermore, any connection is properly referred to as computer-readable media. For example, if instructions are transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of media. However, it should be understood that the computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other temporary media, but are specifically addressed to non-temporary tangible storage media. As used herein, disks and optical discs include compact optical discs (CDs), laser optical discs, optical discs, digital versatile optical discs (DVDs), and Blu-ray discs, where disks typically reproduce data magnetically, while optical discs reproduce data optically using lasers. The combination of the above items should also be included in the scope of computer-readable media.

[0124] Instructions can be executed by one or more processors, such as digital signal processors (DSPs), general-purpose microcontrollers, application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), or other equivalent integrated or discrete logic circuits. Therefore, the term "processor" as used herein can refer to any of the foregoing structures or any other structures suitable for implementing the techniques described herein. Furthermore, in some aspects, the functionality described in the various illustrative logic blocks, modules, and steps described herein can be provided within dedicated hardware and / or software modules configured for encoding and decoding, or incorporated into combined codecs. Moreover, the techniques can be fully implemented within one or more circuit or logic elements.

[0125] The technology of this application can be implemented in a wide variety of devices or apparatuses, including wireless handheld devices, integrated circuits (ICs), or a set of ICs (e.g., chipsets). The various components, modules, or units described in this application are intended to emphasize functional aspects of the apparatus for performing the disclosed technology, but do not necessarily need to be implemented by different hardware units. In fact, as described above, the various units can be combined with suitable software and / or firmware within coded hardware units, or provided via interoperable hardware units (containing one or more processors as described above).

[0126] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the specific descriptions of the corresponding steps in the foregoing method embodiments, and will not be repeated here.

[0127] It should be understood that in the description of this application, unless otherwise stated, " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B can represent A or B; where A and B can be singular or plural. Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple. Additionally, to facilitate a clear description of the technical solutions of the embodiments of this application, the terms "first," "second," etc., are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first," "second," etc., do not limit the quantity or execution order, and the terms "first," "second," etc., do not necessarily imply difference. In this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being better or more advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0128] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the division of units is merely a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. The coupling, direct coupling, or communication connection shown or discussed between each other may be indirect coupling or communication connection through some interfaces, apparatuses, or units, and may be electrical, mechanical, or other forms.

[0129] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0130] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. This computer program product includes one or more computer instructions. When these computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in or transmitted through a computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media can be read-only memory (ROM), random access memory (RAM), or magnetic media, such as floppy disks, hard disks, magnetic tapes, magnetic disks, or optical media, such as digital versatile discs (DVDs), or semiconductor media, such as solid state disks (SSDs).

[0131] The above description is merely a specific implementation of the embodiments of this application, but the protection scope of the embodiments of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the embodiments of this application should be covered within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of this application should be determined by the protection scope of the claims.

[0132] The device embodiments described above are merely illustrative. The units and modules described as separate components may or may not be physically separate. Furthermore, some or all of the units and modules can be selected to achieve the purpose of this embodiment, depending on actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0133] The above description is only a specific embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An energy storage converter, characterized in that, The energy storage converter includes a full-bridge converter, an active clamping circuit, and a DC-DC converter; the first port of the full-bridge converter is connected to the grid side, and the second port of the full-bridge converter is connected to the first port of the active clamping circuit; the second port of the active clamping circuit is connected to the first port of the DC-DC converter, and the second port of the DC-DC converter is connected to the energy storage device; wherein: The full-bridge converter is used to rectify AC power into DC power when the energy storage converter is in a charging state; and to invert DC power into AC power when the energy storage converter is in a discharging state. The active clamping circuit is used to raise the charging voltage when the energy storage converter is in a charging state and to lower the discharge voltage when the energy storage converter is in a discharging state. The DC-DC converter is used to adjust the charging voltage according to a preset ratio when the energy storage converter is in a charging state, and to adjust the discharging voltage according to the preset ratio when the energy storage converter is in a discharging state.

2. The energy storage converter according to claim 1, characterized in that, The energy storage converter also includes an LCL filter; the first port of the full-bridge converter is connected to the grid side through the LCL filter.

3. The energy storage converter according to claim 1, characterized in that, The full-bridge converter is a full-bridge converter based on SiC-MOSFET power devices.

4. The energy storage converter according to claim 1, characterized in that, The DC-DC converter is a DC-DC converter based on SiC-MOSFET power devices.

5. The energy storage converter according to any one of claims 1-4, characterized in that, The full-bridge converter is a three-phase full-bridge converter. The first port of the full-bridge converter includes a third port connected to grid side A, a fourth port connected to grid side B, and a fifth port connected to grid side C. The active clamping circuit includes a first active clamping circuit, a second active clamping circuit, and a third active clamping circuit. The second port of the active clamping circuit includes the second port of the first active clamping circuit, the second port of the second active clamping circuit, and the second port of the third active clamping circuit. The DC-DC converter includes a first DC-DC converter, a second DC-DC converter, and a third DC-DC converter. The first port of the DC-DC converter includes the first port of the first DC-DC converter, the first port of the second DC-DC converter, and the first port of the third DC-DC converter. The second port of the full-bridge converter is connected to the first port of the first active clamping circuit; the second port of the full-bridge converter is connected to the first port of the second active clamping circuit; the second port of the full-bridge converter is connected to the first port of the third active clamping circuit; the second port of the first active clamping circuit is connected to the first port of the first DC-DC converter; the second port of the second active clamping circuit is connected to the first port of the second DC-DC converter. The second port of the third active clamping circuit is connected to the first port of the third DC-DC converter.

6. The energy storage converter according to any one of claims 1-4, characterized in that, The full-bridge converter includes a first sub-converter corresponding to A, a second sub-converter corresponding to B, and a third sub-converter corresponding to C; the first port of the full-bridge converter includes the first port of the first sub-converter, the first port of the second sub-converter, and the first port of the third sub-converter; the second port of the full-bridge converter includes the second port of the first sub-converter, the second port of the second sub-converter, and the second port of the third sub-converter. The active clamping circuit includes a first active clamping circuit, a second active clamping circuit, and a third active clamping circuit. The first port of the active clamping circuit includes the first port of the first active clamping circuit, the first port of the second active clamping circuit, and the first port of the third active clamping circuit. The second port of the active clamping circuit includes the second port of the first active clamping circuit, the second port of the second active clamping circuit, and the second port of the third active clamping circuit. The DC-DC converter includes a first DC-DC converter, a second DC-DC converter, and a third DC-DC converter. The first port of the DC-DC converter includes the first port of the first DC-DC converter, the first port of the second DC-DC converter, and the first port of the third DC-DC converter. The second port of the first sub-converter is connected to the first port of the first active clamping circuit; the second port of the second sub-converter is connected to the first port of the second active clamping circuit; the second port of the third sub-converter is connected to the first port of the third active clamping circuit; the second port of the first active clamping circuit is connected to the first port of the first DC-DC converter; the second port of the second active clamping circuit is connected to the first port of the second DC-DC converter. The second port of the third active clamping circuit is connected to the first port of the third DC-DC converter.

7. The energy storage converter according to claim 5 or 6, characterized in that, Each of the first, second, and third active clamping circuits includes an inductor, a capacitor, and an active clamping power switch; a first port of the active clamping circuit includes a corresponding first port of the inductor; a second port of the inductor is connected to a first port of the capacitor; a second port of the capacitor is connected to the source of the active clamping power switch; a second port of the active clamping circuit includes a second port of the inductor and the drain of the active clamping power switch, wherein: The active clamping power switch is used to control the active clamping circuit to raise the charging voltage when the energy storage converter is in a charging state and to lower the discharge voltage when the energy storage converter is in a discharging state.

8. The energy storage converter according to claim 7, characterized in that, Each of the first, second, and third DC-DC converters includes a primary-side high-frequency H-bridge converter, a high-frequency transformer, and a secondary-side high-frequency H-bridge converter; the first port of the primary-side high-frequency H-bridge converter is connected to the active clamping circuit, and the second port of the primary-side high-frequency H-bridge converter is connected to the first port of the high-frequency transformer; the second port of the high-frequency transformer is connected to the first port of the secondary-side high-frequency H-bridge converter, and the second port of the secondary-side high-frequency H-bridge converter is connected to an energy storage device.

9. The energy storage converter according to claim 8, characterized in that, The primary-side high-frequency H-bridge converter further includes a first power switch, a second power switch, a third power switch, and a fourth power switch; the first port of the primary-side high-frequency H-bridge converter includes the drain of the first power switch, the source of the second power switch, the drain of the third power switch, and the source of the fourth power switch; the second port of the primary-side high-frequency H-bridge converter includes the source of the first power switch, the drain of the second power switch, the source of the third power switch, and the drain of the fourth power switch.

10. The energy storage converter according to claim 9, characterized in that, The active clamping power switch is also used for: It is disconnected when the first power switch and the third power switch are both closed simultaneously; It closes when both the first power switch and the third power switch are simultaneously off; Disconnect when the first power switch is off and the third power switch is closed; It closes when the first power switch is closed and the third power switch is open.

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