Wide voltage bidirectional charging and discharging device and control method thereof

Abstract

The present invention discloses a wide-voltage bidirectional charging and discharging device and a control method thereof. The wide-voltage bidirectional charging and discharging device includes a first bidirectional inverter module, a first transformer, a second bidirectional inverter module, a first voltage conversion module and a control module. The control module controls the first voltage conversion module to switch to a step-up conversion state or a step-down conversion state according to the charging and discharging state, the voltage of the first DC port, the voltage of the fourth DC port, and the turns ratio of the first transformer. The technical solution monitors the voltage in real time and intelligently switches the step-up or step-down state according to the turns ratio of the first transformer, thereby realizing bidirectional charging and discharging control within a wide voltage range. The technical solution not only solves the problems of single function and limited adaptation range of existing equipment, but also greatly improves the compatibility with batteries and loads of different voltage levels, meets the requirements of efficient and flexible charging and discharging in multiple scenarios, and has good applicability and promotion value.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage inverters, and in particular to a wide-voltage bidirectional charging and discharging device and a control method thereof. Background Art

[0002] With the rapid development of renewable energy technologies, green energy sources such as solar and wind power are widely used in various energy systems. Furthermore, the increasing popularity of electric vehicles, outdoor energy storage, and emergency power applications has driven strong demand for efficient and flexible charging and discharging equipment. However, existing charging and discharging equipment generally suffers from limited functionality and application scenarios. For example, most traditional devices only support one-way charging or discharging, making them incompatible with battery systems of multiple voltage levels. Furthermore, existing equipment is often unable to achieve cross-voltage charging compatibility for high-voltage battery systems (such as 300V to 500V) used in cold chain transportation and low-voltage battery systems (such as 24V and 48V) used in RVs. This problem is particularly prominent in distributed energy systems, outdoor portable energy storage equipment, and emergency rescue.

[0003] In practical applications, common buck-boost topologies such as the LLC resonant converter and phase-shifted full-bridge circuit have limited output voltage adjustment ranges. For example, the output voltage of an LLC converter can generally only be adjusted between 0.5 and 1.2 times the rated value, and the output adjustment range of a phase-shifted full-bridge circuit is only around 0.2 to 1 times the rated value. These limitations make it difficult for these devices to meet the bidirectional charging and discharging requirements of a wide input and output voltage range. Summary of the Invention

[0004] The embodiments of the present invention provide a wide voltage bidirectional charge and discharge device and a control method thereof to solve the above technical problems.

[0005] A first aspect of an embodiment of the present invention provides a wide voltage bidirectional charge and discharge device, comprising:

[0006] A first bidirectional inverter module includes a first DC port and a first AC port, and is used for bidirectional conversion between DC voltage and AC voltage;

[0007] a first transformer comprising a first primary coil and a first secondary coil, wherein the first primary coil is connected to a first AC port of the first bidirectional inverter module;

[0008] a second bidirectional inverter module, comprising a second AC port and a second DC port, wherein the second AC port is connected to the first secondary coil to perform bidirectional conversion between AC voltage and DC voltage;

[0009] a first voltage conversion module, comprising a third DC port and a fourth DC port, wherein the third DC port is connected to the second DC port and is configured to switch between a step-up conversion state and a step-down conversion state;

[0010] a control module, which is respectively connected to the first bidirectional inverter module, the second bidirectional inverter module and the first voltage conversion module, and is used to control the first voltage conversion module to switch to a step-up conversion state or a step-down conversion state according to the charge and discharge state, the voltage of the first DC port, the voltage of the fourth DC port, and the turns ratio of the first transformer.

[0011] Optionally, when in the charging state, the fourth DC port inputs a first voltage, and the first DC port outputs a second voltage, and the control module is configured to control the first voltage conversion module to switch to a step-down conversion state when a ratio between the second voltage and the first voltage is greater than a turns ratio between the first secondary coil and the first primary coil of the first transformer;

[0012] The control module is further configured to control the first voltage conversion module to switch to a boost conversion state when a ratio between the second voltage and the first voltage is smaller than a turns ratio between the first secondary coil and the first primary coil of the first transformer.

[0013] Optionally, when in the discharging state, the first DC port inputs a third voltage, and the fourth DC port outputs a fourth voltage, and the control module is configured to control the first voltage conversion module to switch to a boost conversion state when a ratio between the fourth voltage and the third voltage is greater than a turns ratio between the first secondary coil and the first primary coil of the first transformer;

[0014] The control module is further configured to control the first voltage conversion module to switch to a step-down conversion state when a ratio between the fourth voltage and the third voltage is smaller than a turns ratio between the first secondary coil and the first primary coil of the first transformer.

[0015] Optionally, the first voltage conversion module includes a first switching switch, a first inductor, a first switching tube, a second switching tube and a second switching switch, the first common end of the first switching switch is the first end of the third DC port, the first switching end of the first switching switch is respectively connected to the first end of the first inductor and the fourth switching end of the second switching switch, the second switching end of the first switching switch is respectively connected to the second end of the first switching tube and the third switching end of the second switching switch, the second end of the first inductor is respectively connected to the first end of the first switching tube and the first end of the second switching tube, the second end of the second switching tube is the second end of the third DC port and the second end of the fourth DC port, and the second common end of the second switching switch is the first end of the fourth DC port.

[0016] Optionally, the control module controls the first common end of the first switching switch to be connected to the first switching end of the first switching switch, and controls the second common end of the second switching switch to be connected to the third switching end of the second switching switch, so as to control the first voltage conversion module to switch to the step-down conversion state.

[0017] Optionally, the control module controls the first common end of the first switching switch to be connected to the second switching end of the first switching switch, and controls the second common end of the second switching switch to be connected to the fourth switching end of the second switching switch, so as to control the first voltage conversion module to switch to the boost conversion state.

[0018] Optionally, the wide voltage bidirectional charge and discharge device further includes:

[0019] a third bidirectional inverter module, comprising a fifth DC port and a fifth AC port, for bidirectionally converting a DC voltage into an AC voltage;

[0020] a second transformer comprising a second primary coil and a second secondary coil, wherein the second primary coil is connected to the fifth AC port of the third bidirectional inverter module;

[0021] a fourth bidirectional inverter module, comprising a sixth AC port and a sixth DC port, wherein the sixth AC port is connected to the second secondary coil to perform bidirectional conversion between AC voltage and DC voltage;

[0022] a second voltage conversion module, comprising a seventh DC port and an eighth DC port, wherein the seventh DC port is connected to the sixth DC port, and the eighth DC port is connected to the fourth DC port, and is configured to switch between a step-up conversion state and a step-down conversion state.

[0023] Optionally, the second voltage conversion module includes a third switching switch, a second inductor, a third switching tube, a fourth switching tube and a fourth switching switch, the third common end of the third switching switch is the first end of the fifth DC port, the fifth switching end of the third switching switch is respectively connected to the first end of the second inductor and the eighth switching end of the fourth switching switch, the sixth switching end of the third switching switch is respectively connected to the second end of the third switching tube and the seventh switching end of the fourth switching switch, the second end of the second inductor is respectively connected to the first end of the third switching tube and the first end of the fourth switching tube, the second end of the fourth switching tube is the second end of the third DC port and the second end of the fourth DC port, and the fourth common end of the fourth switching switch is the first end of the fourth DC port.

[0024] A second aspect of an embodiment of the present invention provides a control method for the wide voltage bidirectional charge and discharge device according to the first aspect, the control method comprising:

[0025] The first voltage conversion module is controlled to switch to a step-up conversion state or a step-down conversion state according to the charge and discharge state, the voltage of the first DC port, the voltage of the fourth DC port, and the turns ratio of the first transformer.

[0026] Optionally, when in a charging state, the fourth DC port inputs a first voltage, and the first DC port outputs a second voltage, and controlling the first voltage conversion module to switch to a step-up conversion state or a step-down conversion state according to the charging and discharging state, the voltage of the first DC port, the voltage of the fourth DC port, and the turns ratio of the first transformer includes:

[0027] When the ratio between the second voltage and the first voltage is greater than the turns ratio of the first secondary coil and the first primary coil of the first transformer, the first voltage conversion module is controlled to switch to the step-down conversion state; when the ratio between the second voltage and the first voltage is less than the turns ratio of the first secondary coil and the first primary coil of the first transformer, the first voltage conversion module is controlled to switch to the step-up conversion state.

[0028] The technical effect of the embodiment of the present invention is: this technical solution realizes bidirectional charging and discharging control within a wide voltage range by setting a first bidirectional inverter module, a first transformer, a second bidirectional inverter module and a first voltage conversion module, cooperating with the control module to monitor the voltage in real time and intelligently switch the boost or buck state according to the turns ratio of the first transformer. This technical solution not only solves the problems of single function and limited adaptation range of existing equipment, but also greatly improves the compatibility with batteries and loads of different voltage levels, meets the efficient and flexible charging and discharging requirements in multiple scenarios, and has good applicability and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0030] Figure 1 This is a first structural schematic diagram of a wide-voltage bidirectional charge-discharge device provided in Example 1 of the present invention;

[0031] Figure 2 This is a structural diagram of a first voltage conversion module of a wide-voltage bidirectional charge and discharge device provided in Example 1 of the present invention;

[0032] Figure 3 This is a first circuit diagram of a wide-voltage bidirectional charge and discharge device provided in the first embodiment of the present invention;

[0033] Figure 4 This is a first connection relationship diagram in a first circuit diagram of a wide-voltage bidirectional charge and discharge device provided in the first embodiment of the present invention;

[0034] Figure 5 This is an equivalent circuit diagram of the first connection relationship in the first circuit diagram of a wide-voltage bidirectional charge and discharge device provided in the first embodiment of the present invention;

[0035] Figure 6 This is a second connection relationship diagram in the first circuit diagram of a wide voltage bidirectional charge and discharge device provided in the first embodiment of the present invention;

[0036] Figure 7 This is an equivalent circuit diagram of the second connection relationship in the first circuit diagram of a wide-voltage bidirectional charge and discharge device provided in the first embodiment of the present invention;

[0037] Figure 8 This is a second structural diagram of a wide-voltage bidirectional charge-discharge device provided in the first embodiment of the present invention;

[0038] Figure 9 This is a structural diagram of a second voltage conversion module of a wide-voltage bidirectional charge and discharge device provided in Example 1 of the present invention;

[0039] Figure 10 This is a second circuit diagram of a wide-voltage bidirectional charge and discharge device provided in the first embodiment of the present invention;

[0040] In the figure: 101, first bidirectional inverter module; 102, first transformer; 103, second bidirectional inverter module; 104, first voltage conversion module; 105, control module; 111, first switching switch; 112, first inductor; 113, first switching tube; 114, second switching switch; 115, second switching tube; 201, third bidirectional inverter module; 202, second transformer; 203, fourth bidirectional inverter module; 204, second voltage conversion module; 211, third switching switch; 212, second inductor; 213, third switching tube; 214, fourth switching switch; 215, fourth switching tube. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] It should be understood that the present invention can be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the invention to those skilled in the art. In the drawings, the dimensions and relative dimensions of layers and regions may be exaggerated for clarity. Like reference numerals denote like elements throughout.

[0043] It should be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it may be directly on, adjacent to, connected to, or coupled to the other element or layer, or there may be intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there may be no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or part from another element, component, region, layer, or part. Thus, a first element, component, region, layer, or part discussed below may be represented as a second element, component, region, layer, or part without departing from the teachings of the present invention.

[0044] The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present invention. When used herein, the singular forms "a", "an", and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0045] In order to fully understand the present invention, detailed structures and steps will be provided in the following description to illustrate the technical solutions proposed by the present invention. Preferred embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention may also have other implementations.

[0046] Example 1

[0047] This embodiment provides a wide voltage bidirectional charging and discharging device, such as Figure 1 Shown, including:

[0048] A first bidirectional inverter module 101 includes a first DC port A1 and a first AC port B1, and is used for bidirectional conversion between DC voltage and AC voltage;

[0049] A first transformer 102 includes a first primary coil and a first secondary coil, wherein the first primary coil is connected to the first AC port B1 of the first bidirectional inverter module 101;

[0050] A second bidirectional inverter module 103 includes a second AC port B2 and a second DC port A2, wherein the second AC port B2 is connected to the first secondary coil to perform bidirectional conversion between AC voltage and DC voltage;

[0051] The first voltage conversion module 104 includes a third DC port A3 and a fourth DC port A4, wherein the third DC port A3 is connected to the second DC port A2 and is configured to switch between the third DC port A3 and the fourth DC port A4 to perform a step-up conversion state or a step-down conversion state;

[0052] The control module 105 is respectively connected to the first bidirectional inverter module 101, the second bidirectional inverter module 103 and the first voltage conversion module 104, and is used to control the first voltage conversion module 104 to switch to a step-up conversion state or a step-down conversion state according to the charge and discharge state, the voltage of the first DC port A1, the voltage of the fourth DC port A4, and the turns ratio of the first transformer 102.

[0053] The first bidirectional inverter module 101 includes a first DC port A1 and a first AC port B1, and is used to convert DC voltage to AC voltage or rectify AC voltage to DC voltage, supporting bidirectional energy conversion operations for charging and discharging. The first DC port A1 is connected to a first external device. The first transformer 102 includes a first primary coil and a first secondary coil. The first primary coil is connected to the AC port of the first bidirectional inverter module 101. The first transformer 102 is used to step up or down the AC power and achieve electrical isolation between the input and output. Its turns ratio (N1:N2) provides a reference for subsequent voltage switching control. The second bidirectional inverter module 103 includes a second AC port B2 and a second DC port A2. The second AC port B2 is connected to the first secondary coil of the first transformer 102. The second bidirectional inverter module 103 is used to achieve bidirectional energy conversion between the AC output of the first transformer 102 and the DC power on the battery side. The first voltage conversion module 104 includes a third DC port A3 and a fourth DC port A4. The third DC port A3 is connected to the second DC port A2 of the second bidirectional inverter module 103, and the fourth DC port A4 is connected to a second external device. The first voltage conversion module 104 can switch between a boost mode (BOOST) and a buck mode (BUCK) to achieve energy matching between external devices of different voltage levels. The control module 105 is connected to the first bidirectional inverter module 101, the second bidirectional inverter module 103, and the first voltage conversion module 104, respectively. Its main functions are: monitoring the voltages of the first DC port A1 and the fourth DC port A4; determining whether the system is currently in a charging or discharging state; and controlling the first voltage conversion module 104 to enter the corresponding mode based on the voltage ratio and the turns ratio of the first transformer 102 to meet the requirements of energy flow direction and voltage level matching.

[0054] The working process of this embodiment is as follows:

[0055] 1. In discharge mode: When power output from a first external device is input through the first DC port A1, the first bidirectional inverter module 101 converts DC power into AC power. The AC power is boosted or stepped down by the first transformer 102 and then output to the secondary side. The second bidirectional inverter module 103 converts the AC power into DC power. The control module 105 determines the relationship between the voltage ratio between the fourth DC port A4 and the first DC port A1 and the turns ratio N2 / N1 between the secondary and primary coils of the first transformer 102, and automatically controls the first voltage conversion module 104 to enter a boost or buck mode. Finally, the first voltage conversion module 104 matches the DC voltage to the fourth DC port A4 to charge the second external device.

[0056] 2. In charging mode: When power output from a second external device is input via the fourth DC port A4, the control module 105 determines the relationship between the voltage ratio between the fourth DC port A4 and the first DC port A1 and the turns ratio N2 / N1 of the first transformer 102, and automatically controls the first voltage conversion module 104 to enter a boost or buck mode. The second bidirectional inverter module 103 converts DC power into AC power. The AC power passes through the first transformer 102 and is converted by the first bidirectional inverter module 101 before being output to the first external device, thereby achieving a charging function.

[0057] 3. Mode switching control: The control module 105 monitors the system status and voltage data in real time; automatically determines whether the current state is charging or discharging, and switches the boost / down state according to the voltage ratio to ensure the automation and efficiency of the system operation.

[0058] The technical effect of the technical solution provided in the first embodiment is that: this technical solution realizes bidirectional charge and discharge control within a wide voltage range by setting a first bidirectional inverter module 101, a first transformer 102, a second bidirectional inverter module 103 and a first voltage conversion module 104, cooperating with the control module 105 to monitor the voltage in real time and intelligently switch the boost or buck state according to the turns ratio of the first transformer 102. This technical solution not only solves the problems of single function and limited adaptability of existing equipment, but also greatly improves the compatibility with batteries and loads of different voltage levels, meets the requirements of efficient and flexible charging and discharging in multiple scenarios, and has good applicability and promotion value.

[0059] As an embodiment, when in the charging state, the fourth DC port A4 inputs a first voltage and the first DC port A1 outputs a second voltage. The control module 105 is used to control the first voltage conversion module 104 to switch to the step-down conversion state when the ratio between the second voltage and the first voltage is greater than the turns ratio between the first secondary coil and the first primary coil of the first transformer 102; the control module 105 is also used to control the first voltage conversion module 104 to switch to the step-up conversion state when the ratio between the second voltage and the first voltage is less than the turns ratio between the first secondary coil and the first primary coil of the first transformer 102.

[0060] When the wide-voltage bidirectional charge-discharge device is in the charging state, the fourth DC port A4 is connected to an external power source, such as a photovoltaic panel or a high-voltage DC bus, and inputs the first voltage V1. The first DC port A1 is connected to the battery to output the second voltage V2, i.e., to charge the battery. The control module 105 monitors the voltage values ​​of the first voltage V1 and the second voltage V2 in real time, and compares and determines the value based on the ratio between the two voltages and the turns ratio of the first transformer 102 (N2 / N1, i.e., the first secondary coil to the first primary coil). The specific control logic is as follows:

[0061] 1. If the ratio of the second voltage to the first voltage (V2 / V1) is greater than the turns ratio (N2 / N1), the input voltage is relatively high and needs to be reduced to a suitable charging voltage for the battery. The control module 105 controls the first voltage conversion module 104 to enter the buck conversion state. Through the buck adjustment, the battery obtains a safe and effective charging voltage.

[0062] 2. If the ratio V2 / V1 of the second voltage to the first voltage is less than the turns ratio N2 / N1, it indicates that the battery voltage is relatively high and needs to be increased to meet charging requirements. The control module 105 controls the first voltage conversion module 104 to enter the boost conversion state, thereby increasing the converted voltage to a level suitable for battery charging.

[0063] The technical benefits of this implementation are: By monitoring the input-to-output voltage ratio in real time through control module 105 and determining it based on the turns ratio of first transformer 102, intelligent switching between boost and buck modes is achieved, automatically adjusting the charging path based on varying battery voltages and input voltage conditions. This solution not only improves charging efficiency and system compatibility, but also reduces manual intervention, achieving automation and high adaptability in the charging and discharging process. It is particularly suitable for bidirectional charging and discharging applications across multiple scenarios and voltage levels.

[0064] As an embodiment, when in the discharging state, the first DC port A1 inputs a third voltage, and the fourth DC port A4 outputs a fourth voltage. The control module 105 is used to control the first voltage conversion module 104 to switch to a step-up conversion state when the ratio between the fourth voltage and the third voltage is greater than the turns ratio between the first secondary coil and the first primary coil of the first transformer 102; the control module 105 is also used to control the first voltage conversion module 104 to switch to a step-down conversion state when the ratio between the fourth voltage and the third voltage is less than the turns ratio between the first secondary coil and the first primary coil of the first transformer 102.

[0065] When the wide-voltage bidirectional charge-discharge device is in the discharge state, the first DC port A1 is connected to the battery, inputting the third voltage V3 from the battery; the fourth DC port A4 is connected to the external load, outputting the fourth voltage V4. At this point, the system's goal is to convert the battery voltage into an output voltage that meets the load's requirements. To stabilize the output voltage and meet the target voltage requirement, the control module 105 compares the ratio of the fourth voltage V4 to the third voltage V3 with the turns ratio (N2 / N1) of the first transformer 102, and controls the operating state of the first voltage conversion module 104. The specific control logic is as follows:

[0066] 1. If the ratio V4 / V3 of the fourth voltage to the third voltage is greater than N2 / N1, indicating that the target output voltage is higher than the battery voltage after adjustment by the first transformer 102, the control module 105 controls the first voltage conversion module 104 to switch to the boost conversion state, thereby increasing the battery voltage to the desired output voltage to ensure normal operation of the load.

[0067] 2. If the ratio V4 / V3 of the fourth voltage to the third voltage is less than N2 / N1, indicating that the target output voltage is lower than the converted battery voltage, the control module 105 controls the first voltage conversion module 104 to switch to the buck conversion state. Through buck regulation, the output voltage is stabilized below the target value to avoid overvoltage on the load.

[0068] The technical benefit of this implementation lies in the automatic selection and switching of the boost or buck path during discharge, achieved by introducing a dynamic ratio determination mechanism. This approach flexibly adjusts the energy transfer path based on the real-time relationship between the battery voltage and the target output voltage, improving discharge efficiency and voltage matching accuracy, enhancing the system's ability to adapt to loads of varying voltage levels, and ensuring the stability and safety of the discharge process, offering excellent applicability and scalability.

[0069] As an implementation method, Figure 2As shown, the first voltage conversion module 104 includes a first switch 111, a first inductor 112, a first switching tube 113, a second switching tube 115 and a second switching switch 114. The first common terminal a0 of the first switching switch 111 is the first end of the third DC port A3, the first switching terminal a1 of the first switching switch 111 is respectively connected to the first end of the first inductor 112 and the fourth switching terminal b2 of the second switching switch 114, the second switching terminal a2 of the first switching switch 111 is respectively connected to the second end of the first switching tube 113 and the third switching terminal b1 of the second switching switch 114, the second end of the first inductor 112 is respectively connected to the first end of the first switching tube 113 and the first end of the second switching tube 115, the second end of the second switching tube 115 is the second end of the third DC port A3 and the second end of the fourth DC port A4, and the second common terminal b0 of the second switching switch 114 is the first end of the fourth DC port A4. The control module 105 controls the first common terminal a0 of the first switch 111 to be connected to the first switching terminal a1 of the first switch 111, and controls the second common terminal b0 of the second switch 114 to be connected to the third switching terminal b1 of the second switch 114, thereby controlling the first voltage conversion module 104 to switch to the step-down conversion state. The control module 105 controls the first common terminal a0 of the first switch 111 to be connected to the second switching terminal a2 of the first switch 111, and controls the second common terminal b0 of the second switch 114 to be connected to the fourth switching terminal b2 of the second switch 114, thereby controlling the first voltage conversion module 104 to switch to the step-up conversion state.

[0070] The first switch 111 is a three-terminal switching device, comprising a first common terminal a0, a first switching terminal a1, and a second switching terminal a2. The first common terminal a0 is connected to the first terminal of the third DC port A3 and is used to select the current flow direction. The control module 105 controls the first common terminal a0 of the first switch 111 to be connected to the first switching terminal a1 or the second switching terminal a2, depending on whether the device is currently in the boost or buck mode. The second switch 114 is also a three-terminal device, comprising a second common terminal b0, a third switching terminal b1, and a fourth switching terminal b2. The second common terminal b0 is connected to the first terminal of the fourth DC port A4. Its two switching terminals are respectively connected to the path extending from the first switching terminal a1 and the second switching terminal a2 of the first switch 111. The control module 105 controls its conduction path to form a complete current flow path. One terminal of the first inductor 112 is connected to the first switching terminal a1 of the first switch 111, and the other terminal is respectively connected to the first switching transistor 113 and the second switching transistor 115. It is used for energy storage and energy conversion and is the core component for implementing the buck or boost mode. The first switch 113 is configured to operate in conjunction with the first inductor 112 at a specific timing to achieve discontinuous current control. One end of the first switch 113 is connected to the first inductor 112, and the other end is connected to ground (forming a path with the second switch 114). The second switch 115 is connected in parallel with the first switch 113, connecting the first inductor 112 and the ground path. Its second end connects to the second end of the third DC port A3 and the second end of the fourth DC port A4. It is used to control the current release path and synchronous rectification.

[0071] The working process of this embodiment is as follows:

[0072] In the charging state: 1. Buck conversion state: the control module 105 controls the first common terminal a0 of the first switching switch 111 to be connected to the first switching terminal a1, and the second common terminal b0 of the second switching switch 114 to be connected to the third switching terminal b1; at this time, the current flows from the second switching switch 114 to the first switching tube 113 to the first inductor 112 and then to the first switching switch 111; the first switching tube 113 adjusts the current of the first inductor 112 during the high-frequency conduction and shutdown process, thereby achieving voltage step-down output.

[0073] 2. Boost conversion state: The control module 105 controls the first common terminal a0 of the first switch 111 to be connected to the second switch terminal a2, and the second common terminal b0 of the second switch 114 to be connected to the second switch terminal b2; the current flows from the second switch 114 to the first inductor 112 to the first switch tube 113 and then to the first switch 111; the second switch tube 115 is controlled to charge the first inductor 112, and the first inductor 112 releases energy to the second switch tube 115 and outputs it to the fourth DC port A4; thus achieving a boost operation in which the output voltage is greater than the input voltage.

[0074] In the discharge state: 1. Buck conversion state: the control module 105 controls the first common terminal a0 of the first switching switch 111 to be connected to the first switching terminal a1, and the second common terminal b0 of the second switching switch 114 to be connected to the third switching terminal b1; at this time, the current flows from the first end of the third DC port A3 through the first switching switch 111 to the first switching tube 113 to the first inductor 112 to the output end (the fourth DC port A4); the first switching tube 113 regulates the current of the first inductor 112 during the high-frequency conduction and shutdown process, thereby achieving voltage step-down output.

[0075] 2. Boost conversion state: The control module 105 controls the first common terminal a0 of the first switch 111 to be connected to the second switch terminal a2, and the second common terminal b0 of the second switch 114 to be connected to the second switch terminal b2; current flows from the first terminal of the third DC port A3 to the second switch terminal of the first switch 111, to the first inductor 112, and to the first switch tube 113 / the second switch tube 115; the second switch tube 115 is controlled to charge the first inductor 112, and the first inductor 112 releases energy to the second switch tube 115 and outputs it to the fourth DC port A4, thereby achieving a boost operation in which the output voltage is greater than the input voltage.

[0076] The technical advantage of this embodiment is that, by providing the first voltage conversion module 104 and combining it with the intelligent control of the switch state by the control module 105, it enables flexible switching between boost and buck modes within the same circuit structure. This design not only improves the system's adaptability to different voltage inputs and outputs, but also simplifies the hardware structure, improves energy conversion efficiency and control response speed, and possesses excellent versatility and practicality, making it particularly suitable for bidirectional charging and discharging applications in multiple scenarios.

[0077] The present embodiment is described below through a specific circuit structure: Figure 3 As shown, the first bidirectional inverter module 101 includes a first MOS transistor Q1, a second MOS transistor Q2, a third MOS transistor Q3, and a fourth MOS transistor Q4. The drain of the first MOS transistor Q1 and the drain of the second MOS transistor Q2 are commonly connected to a first terminal BAT+ of a first DC port A1 of the first bidirectional inverter module 101. The source of the third MOS transistor Q3 and the source of the fourth MOS transistor Q4 are commonly connected to a second terminal BAT- of the first DC port A1 of the first bidirectional inverter module 101. The source of the first MOS transistor Q1 and the drain of the third MOS transistor Q3 are commonly connected to a first terminal of a first AC port B1 of the first bidirectional inverter module 101. The source of the second MOS transistor Q2 and the drain of the fourth MOS transistor Q4 are commonly connected to a second terminal of the first AC port B1 of the first bidirectional inverter module 101.

[0078] The second bidirectional inverter module 103 includes a first IGBT module Q5, a second IGBT module Q6, a third IGBT module Q7 and a fourth IGBT module Q8; the second end of the first IGBT module Q5 and the first end of the second IGBT module Q6 are connected together to form the second end of the second AC port B2 of the second bidirectional inverter module 103, the second end of the third IGBT module Q7 and the first end of the fourth IGBT module Q8 are connected together to form the first end of the second AC port B2 of the second bidirectional inverter module 103, the first end of the first IGBT module Q5 and the first end of the third IGBT module Q7 are connected together to form the first end of the second DC port A2 of the second bidirectional inverter module 103, and the second end of the second IGBT module Q6 and the second end of the fourth IGBT module Q8 are connected together to form the second end of the second DC port A2 of the second bidirectional inverter module 103.

[0079] In the first voltage conversion module 104, the first switch 111 is a switch S1, the first inductor 112 is an inductor L1, the first switching transistor 113 is a switching transistor Q9, the second switching transistor 115 is a switching transistor Q10, and the second switching switch 114 is a switch S2. The common terminal a0 of the switch S1 is the first end of the third DC port A3. The first switching terminal a1 of the switch S1 is respectively connected to the first end of the inductor L1 and the fourth switching terminal b2 of the switch S2. The second switching terminal a2 of the switch S1 is respectively connected to the second end of the switching transistor Q9 and the third switching terminal b1 of the switch S2. The second end of the inductor L1 is respectively connected to the first end of the switching transistor Q9 and the first end of the switching transistor Q10. The second end of the switch transistor Q10 is connected to the second end of the third DC port A3 and the second end of the fourth DC port A4. The common terminal b0 of the switch S2 is the first end of the fourth DC port A4.

[0080] The working process of this circuit structure is:

[0081] When the system is in the charging state, that is, when the fourth DC port A4 (voltage is Vhv) supplies power to the first DC port A1 (voltage is Vbat), the control logic is as follows:

[0082] 1. When Vhv / Vbat>N2 / N1, it means that the voltage of the fourth DC port A4 is high and needs to be stepped down to charge the low-voltage battery; Figure 4 As shown, the control module 105 drives the common terminal a0 of the switch S1 to switch to the first switching terminal a1 of the switch S1, and drives the common terminal b0 of the switch S2 to switch to the third switching terminal b1 of the switch S2; starts the switch tube Q9 to work, controls the switch tube Q10 to turn off, and performs the BUCK step-down operation; adjusts the BUS voltage by controlling the conduction time of the switch tube Q9; the system works in the open-loop control mode, providing a stable charging voltage to the battery side. The equivalent circuit diagram is shown in FIG. Figure 5 .

[0083] 2. When Vhv / Vbat < N2 / N1, it indicates that the voltage of the fourth DC port is insufficient and needs to be boosted to match the battery charging voltage; as Figure 6 shown, the control module 105 drives the first common terminal a0 of the switch S1 to switch to the second switching terminal a2 of the switch S1, and drives the second common terminal b0 of the switch S2 to switch to the fourth switching terminal b2 of the switch S2; starts the switching transistor Q10 to work and performs BOOST boost operation; controls the switching transistor Q10 to adjust the BUS voltage to be suitable for battery charging; the system still works in an open-loop manner to achieve efficient charging of the battery, and the equivalent circuit diagram is as Figure 7 .

[0084] When the system is in the discharging state, that is, when the first DC port A1 (voltage is Vbat) outputs electric energy to the fourth DC port A4 (voltage is Vhv), the control logic is as follows:

[0085] 1. When Vhv / Vbat > N2 / N1, it indicates that the output target voltage is higher than the current battery voltage; as Figure 4 shown, the control module 105 drives the first common terminal a0 of the switch S1 to switch to the second switching terminal a2 of the switch S1, and drives the second common terminal b0 of the switch S2 to switch to the fourth switching terminal b2 of the switch S2; starts the switching transistor Q10 and performs BOOST boost operation; adjusts the BUS voltage to meet the set target value at the output end; the system can set the output voltage through a display or a communication interface (such as CAN, RS485).

[0086] 2. When Vhv / Vbat < N2 / N1, it indicates that the target output voltage is lower than the battery voltage; as Figure 6 shown, the control module 105 drives the first common terminal a0 of the switch S1 to switch to the first switching terminal a1 of the switch S1, and drives the second common terminal b0 of the switch S2 to switch to the third switching terminal b1 of the switch S2; starts the switching transistor Q9 and performs BUCK buck operation; adjusts the BUS voltage to output a matching voltage to the high-voltage side.

[0087] As an implementation manner, as Figure 8 shown, the wide-voltage bidirectional charge and discharge device further includes:

[0088] A third bidirectional inverter module 201, which includes a fifth DC port A5 and a fifth AC port B5, and is used for bidirectional conversion of DC voltage and AC voltage;

[0089] A second transformer 202, which includes a second primary coil and a second secondary coil, and the second primary coil is connected to the fifth AC port B5 of the third bidirectional inverter module 201;

[0090] a fourth bidirectional inverter module 203, comprising a sixth AC port B6 and a sixth DC port A6, wherein the sixth AC port B6 is connected to the second secondary coil to perform bidirectional conversion between AC voltage and DC voltage;

[0091] The second voltage conversion module 204 includes a seventh DC port A7 and an eighth DC port A8, wherein the seventh DC port A7 is connected to the sixth DC port A6, and the eighth DC port A8 is connected to the fourth DC port A4, and is configured to switch between the seventh DC port A7 and the eighth DC port A8 in a step-up conversion state or a step-down conversion state.

[0092] When the load power increases, the output voltage drops slightly. Control module 105 automatically distributes current based on the voltage of each path. Paths with higher output voltages provide more current, while paths with lower voltages provide less, resulting in automatic energy balancing. Proportional distribution is achieved by presetting different voltage droop slopes (K values). One module acts as the master, regulating the bus voltage in real time. The other modules act as slaves, outputting using a voltage-following + current-limiting method. The master module controls the target voltage based on the bus voltage, while the slave modules only output current consistent with their voltage. Energy distribution is determined by the current or power limit set for each module. When two channels are connected in parallel, the output ends (fourth DC port A4 and eighth DC port A8) of the first voltage conversion module 104 and the second voltage conversion module 204 are connected to the same bus. The control module 105 determines the current system voltage requirement and the available capacity of each path. Through droop control or communication instructions, the power output of the two paths is automatically coordinated. For example, when the load power increases, if the first path has a strong capacity and a small droop ratio, it will prioritize outputting more current. If the battery voltage of the second path is low or its power capacity is limited, its controller automatically reduces the current output to achieve automatic current sharing.

[0093] The technical effect of this embodiment is that by introducing voltage droop control, master-slave control or communication coordination mechanism in the parallel structure, this technical solution can realize dynamic and intelligent energy distribution between dual-channel or multi-channel energy paths, effectively improve system stability and output capacity, avoid power conflicts or current backflow between paths, and is widely applicable to multi-module parallel power supply scenarios such as energy storage systems, DC microgrids, and on-board energy supply systems.

[0094] As an implementation method, Figure 9As shown, the second voltage conversion module 204 includes a third switch 211, a second inductor 212, a third switch tube 213, a fourth switch tube 215 and a fourth switch 214. The third common terminal m0 of the third switch 211 is the first end of the fifth DC port A5, the fifth switch terminal m1 of the third switch 211 is respectively connected to the first end of the second inductor 212 and the eighth switch terminal n2 of the fourth switch 214, the sixth switch terminal m2 of the third switch 211 is respectively connected to the second end of the third switch tube 213 and the seventh switch terminal n1 of the fourth switch 214, the second end of the second inductor 212 is respectively connected to the first end of the third switch tube 213 and the first end of the fourth switch tube 215, the second end of the fourth switch tube 215 is the second end of the third DC port A3 and the second end of the fourth DC port A4, and the fourth common terminal n0 of the fourth switch 214 is the first end of the fourth DC port A4.

[0095] The third switch 211 is used to select different energy paths in different operating modes to achieve switching between boost and buck modes. The second inductor 212, as an energy storage element, stores and releases energy in boost mode and smoothly transmits energy in buck mode, making it a key magnetic component for voltage conversion. Driven by the control module 105, the third switch 213 periodically switches on and off, controlling the buildup and release of the inductor current. Based on the voltage determination result, the control module 105 controls the fourth switch 214 to select the appropriate path to achieve output switching between boost and buck modes. In buck mode (BUCK), the control module 105 controls the third common terminal m0 of the third switch 211 to switch to the fifth switching terminal m1 of the third switch 211, and controls the fourth common terminal n0 of the fourth switch 214 to switch to the seventh switching terminal n1 of the fourth switch 214. Current enters the third switch 211 and is regulated by the second inductor 212, the third switch 213, and the fourth switch 214. In the boost mode (BOOST), the control module 105 controls the third common terminal m0 of the third switch 211 to switch to the sixth switch terminal m2, and the fourth common terminal n0 of the fourth switch 214 to switch to the eighth switch terminal n2. The second inductor 212 controls periodic energy storage and releases it to the fourth DC port A4 to form a boosted output.

[0096] The technical benefit of this embodiment is that, by providing the second voltage conversion module 204, automatic switching between step-up and step-down voltages is achieved between DC ports, ensuring voltage compatibility while also improving the circuit's voltage range and system efficiency. This solution is applicable to a variety of scenarios, including high- and low-voltage hybrid energy storage systems, DC microgrids, and electric vehicle energy management, demonstrating its practicality and potential for widespread adoption.

[0097] The present embodiment is described below through a specific circuit structure: Figure 10As shown, the third bidirectional inverter module 201 includes an eleventh MOS transistor Q11, a twelfth MOS transistor Q12, a thirteenth MOS transistor Q13, and a fourteenth MOS transistor Q14. The drain of the eleventh MOS transistor Q11 and the drain of the twelfth MOS transistor Q12 are commonly connected to the first end of the fifth DC port A5 of the third bidirectional inverter module 201. The source of the thirteenth MOS transistor Q3 and the source of the fourteenth MOS transistor Q14 are commonly connected to the second end of the fifth DC port A5 of the third bidirectional inverter module 201. The source of the eleventh MOS transistor Q11 and the drain of the thirteenth MOS transistor Q13 are commonly connected to the first end of the fifth AC port B5 of the third bidirectional inverter module 201. The source of the twelfth MOS transistor Q12 and the drain of the fourteenth MOS transistor Q14 are commonly connected to the second end of the fifth AC port B5 of the third bidirectional inverter module 201.

[0098] The fourth bidirectional inverter module 203 includes an eleventh IGBT module Q15, a twelfth IGBT module Q16, a thirteenth IGBT module Q17, and a fourteenth IGBT module Q18. The second end of the eleventh IGBT module Q15 and the first end of the twelfth IGBT module Q16 are connected together to form the second end of the sixth AC port B6 of the fourth bidirectional inverter module 203. The second end of the thirteenth IGBT module Q17 and the first end of the fourteenth IGBT module Q18 are connected together to form the first end of the sixth AC port B6 of the fourth bidirectional inverter module 203. The first end of the eleventh IGBT module Q15 and the first end of the thirteenth IGBT module Q17 are connected together to form the first end of the sixth DC port A6 of the fourth bidirectional inverter module 203. The second end of the twelfth IGBT module Q16 and the second end of the fourteenth IGBT module Q18 are connected together to form the second end of the sixth DC port A6 of the fourth bidirectional inverter module 203.

[0099] In the second voltage conversion module 204, the third switch 211 is a switch S3, the second inductor 212 is an inductor L2, the third switch transistor 213 is a switch transistor Q19, the fourth switch transistor 215 is a switch transistor Q20, and the fourth switch 214 is a switch S4. The third common terminal a3 of the switch S3 is connected to the first end of the seventh DC port A7, the fifth switching terminal a4 of the switch S3 is connected to the first end of the inductor L2 and the eighth switching terminal b5 of the switch S4, respectively. The sixth switching terminal a5 of the switch S3 is connected to the second end of the switch transistor Q19 and the seventh switching terminal b4 of the switch S4, respectively. The second end of the inductor L2 is connected to the first end of the switch transistor Q19 and the first end of the switch transistor Q20, respectively. The second end of the switch transistor Q20 is connected to the second end of the seventh DC port A7 and the second end of the eighth DC port A8. The fourth common terminal b3 of the switch S4 is connected to the first end of the eighth DC port A8.

[0100] As an example, through the device communication protocol (traditionally using CAN, RS485, etc.) or display panel, set the discharging device as the host and the charging device as the slave. The host is connected to DC ports BAT1+ and BAT1- (the first DC port), and the slave is connected to DC ports BAT2+ and BAT2- (the fifth DC port). The host reads the slave information and sends the HV voltage value to the slave. The slave adjusts the buckboost circuit through the HV to charge the battery. If the host and slave batteries are both 48V systems, the host determines that the output HV voltage is equal to (Vbat×N2 / N1)+K, where K is a constant; the BOOSTBUCK circuit connected to the host is in the boost state. After the slave receives the HV voltage, the BOOSTBUCK circuit connected to the slave is in the buck state to charge the slave. If the host voltage is lower than the slave voltage, the host is a 24V system and the slave is a 48V system. The host outputs a high-voltage voltage equal to (Vbat × N2 / N1) + K. The BOOSTBUCK circuit connected to the host is in the boost state. After the slave receives the high-voltage voltage, the BOOSTBUCK circuit connected to the slave is in the buck state, charging the slave. If the host voltage is higher than the slave voltage, the host is a 48V system and the slave is a 24V system. The host outputs a high-voltage voltage equal to ((master Vbat + slave Vbat) / 2) × (N2 / N1), where master Vbat is the voltage of the DC port connected to the host and slave Vbat is the voltage of the DC port connected to the slave. The BOOSTBUCK circuit connected to the host is in the buck state. After the slave receives the high-voltage voltage, the BOOSTBUCK circuit connected to the slave is in the buck state, charging the slave. When the voltage levels of the master and slave devices are inconsistent, this technical solution achieves adaptive voltage matching between the high- and low-voltage systems by setting the host's output high-voltage voltage to the average of the host and slave battery voltages multiplied by the transformer turns ratio ((master Vbat + slave Vbat) / 2) × (N2 / N1). When the host voltage is higher than the slave voltage (for example, 48V for the host and 24V for the slave), the host's BOOSTBUCK circuit automatically enters step-down mode to output a stable high-voltage voltage, while the slave's BOOSTBUCK circuit enters buck mode for safe charging. This solution effectively avoids voltage surges and energy backflow, enabling intelligent mutual charging and energy coordination between systems with different voltages, and improving system compatibility and operational efficiency.

[0101] Example 2

[0102] This second embodiment provides a control method for the wide voltage bidirectional charge and discharge device provided in the first embodiment, the control method including:

[0103] The first voltage conversion module is controlled to switch to a step-up conversion state or a step-down conversion state according to the charge and discharge state, the voltage of the first DC port, the voltage of the fourth DC port, and the turns ratio of the first transformer.

[0104] Furthermore, when in the charging state, the fourth DC port inputs the first voltage, and the first DC port outputs the second voltage. The first voltage conversion module is controlled to switch to the step-up conversion state or the step-down conversion state according to the charging and discharging state, the voltage of the first DC port, the voltage of the fourth DC port, and the turns ratio of the first transformer, including:

[0105] When in the charging state, when the ratio between the second voltage and the first voltage is greater than the turns ratio of the first secondary coil and the first primary coil of the first transformer, the first voltage conversion module is controlled to switch to the step-down conversion state; when the ratio between the second voltage and the first voltage is less than the turns ratio of the first secondary coil and the first primary coil of the first transformer, the first voltage conversion module is controlled to switch to the step-up conversion state.

[0106] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A wide voltage bidirectional charge and discharge device, characterized in that: include: A first bidirectional inverter module includes a first DC port and a first AC port, and is used for bidirectional conversion between DC voltage and AC voltage; a first transformer comprising a first primary coil and a first secondary coil, wherein the first primary coil is connected to a first AC port of the first bidirectional inverter module; a second bidirectional inverter module, comprising a second AC port and a second DC port, wherein the second AC port is connected to the first secondary coil to perform bidirectional conversion between AC voltage and DC voltage; a first voltage conversion module, comprising a third DC port and a fourth DC port, wherein the third DC port is connected to the second DC port and is configured to switch between a step-up conversion state and a step-down conversion state; a control module, connected to the first bidirectional inverter module, the second bidirectional inverter module, and the first voltage conversion module, respectively, and configured to control the first voltage conversion module to switch to a step-up conversion state or a step-down conversion state according to a charge and discharge state, a voltage of the first DC port, a voltage of the fourth DC port, and a turns ratio of the first transformer; The wide voltage bidirectional charge and discharge device further includes: a third bidirectional inverter module, comprising a fifth DC port and a fifth AC port, for bidirectionally converting a DC voltage into an AC voltage; a second transformer comprising a second primary coil and a second secondary coil, wherein the second primary coil is connected to the fifth AC port of the third bidirectional inverter module; a fourth bidirectional inverter module, comprising a sixth AC port and a sixth DC port, wherein the sixth AC port is connected to the second secondary coil to perform bidirectional conversion between AC voltage and DC voltage; a second voltage conversion module, comprising a seventh DC port and an eighth DC port, the seventh DC port being connected to the sixth DC port, the eighth DC port being connected to the fourth DC port, and being configured to switch between a step-up conversion state and a step-down conversion state. Among them, the discharging device is the host, and the charging device is the slave. The host is connected to the first DC port, and the slave is connected to the fifth DC port. The host reads the slave information and sends the HV voltage value to the slave. The slave adjusts the buckboost circuit through the HV voltage to charge the battery. The voltage of the host and the slave battery is the same. The host determines that the output HV voltage is equal to (Vbat×N2 / N1)+K, K is a constant, and N2 / N1 is the turns ratio of the secondary coil to the primary coil; the BOOSTBUCK circuit connected to the host is in a boost state. After the slave receives the HV voltage, the BOOSTBUCK circuit connected to the slave is in a buck state to charge the slave; when the host voltage is lower than the slave voltage, the The host outputs an HV voltage equal to (Vbat×N2 / N1)+K, and the BOOSTBUCK circuit connected to the host is in a boost state. After the slave receives the HV voltage, the BOOSTBUCK circuit connected to the slave is in a step-down state to charge the slave. When the host voltage is greater than the slave voltage, the host outputs an HV voltage equal to ((master Vbat+slave Vbat) / 2)×(N2 / N1), wherein master Vbat is the DC port voltage connected to the host, slave Vbat is the DC port voltage connected to the slave, and the BOOSTBUCK circuit connected to the host is in a step-down state. After the slave receives the HV voltage, the BOOSTBUCK circuit connected to the slave is in a step-down state to charge the slave.

2. The wide voltage bidirectional charge and discharge device according to claim 1, wherein: When in the charging state, the fourth DC port inputs a first voltage, and the first DC port outputs a second voltage, and the control module is configured to control the first voltage conversion module to switch to a step-down conversion state when a ratio between the second voltage and the first voltage is greater than a turns ratio between the first secondary coil and the first primary coil of the first transformer; The control module is further configured to control the first voltage conversion module to switch to a boost conversion state when a ratio between the second voltage and the first voltage is smaller than a turns ratio between the first secondary coil and the first primary coil of the first transformer.

3. The wide voltage bidirectional charge and discharge device according to claim 1, wherein: When in the discharging state, the first DC port inputs a third voltage, and the fourth DC port outputs a fourth voltage, and the control module is configured to control the first voltage conversion module to switch to a boost conversion state when a ratio between the fourth voltage and the third voltage is greater than a turns ratio between the first secondary coil and the first primary coil of the first transformer; The control module is further configured to control the first voltage conversion module to switch to a step-down conversion state when a ratio between the fourth voltage and the third voltage is smaller than a turns ratio between the first secondary coil and the first primary coil of the first transformer.

4. The wide voltage bidirectional charge and discharge device according to claim 2 or 3, characterized in that: The first voltage conversion module includes a first switch, a first inductor, a first switching tube, a second switching tube and a second switch. The first common end of the first switching switch is the first end of the third DC port. The first switching end of the first switching switch is respectively connected to the first end of the first inductor and the fourth switching end of the second switching switch. The second switching end of the first switching switch is respectively connected to the second end of the first switching tube and the third switching end of the second switching switch. The second end of the first inductor is respectively connected to the first end of the first switching tube and the first end of the second switching tube. The second end of the second switching tube is the second end of the third DC port and the second end of the fourth DC port. The second common end of the second switching switch is the first end of the fourth DC port.

5. The wide voltage bidirectional charge and discharge device according to claim 4, wherein: The control module controls the first common end of the first switch to connect to the first switching end of the first switch, and controls the second common end of the second switch to connect to the third switching end of the second switch, so as to control the first voltage conversion module to switch to the step-down conversion state.

6. The wide voltage bidirectional charge and discharge device according to claim 4, wherein: The control module controls the first common terminal of the first switch to connect to the second switch terminal of the first switch, and controls the second common terminal of the second switch to connect to the fourth switch terminal of the second switch, so as to control the first voltage conversion module to switch to the boost conversion state.

7. The wide voltage bidirectional charge and discharge device according to claim 1, wherein: The second voltage conversion module includes a third switch, a second inductor, a third switching tube, a fourth switching tube and a fourth switch. The third common end of the third switching switch is the first end of the fifth DC port. The fifth switching end of the third switching switch is respectively connected to the first end of the second inductor and the eighth switching end of the fourth switching switch. The sixth switching end of the third switching switch is respectively connected to the second end of the third switching tube and the seventh switching end of the fourth switching switch. The second end of the second inductor is respectively connected to the first end of the third switching tube and the first end of the fourth switching tube. The second end of the fourth switching tube is the second end of the third DC port and the second end of the fourth DC port. The fourth common end of the fourth switching switch is the first end of the fourth DC port.

8. A control method based on the wide voltage bidirectional charge and discharge device according to claim 1, characterized in that: The control method includes: The first voltage conversion module is controlled to switch to a step-up conversion state or a step-down conversion state according to the charge and discharge state, the voltage of the first DC port, the voltage of the fourth DC port, and the turns ratio of the first transformer.

9. The control method according to claim 8, wherein: When in a charging state, the fourth DC port inputs a first voltage, and the first DC port outputs a second voltage, and the controlling the first voltage conversion module to switch to a step-up conversion state or a step-down conversion state according to the charging and discharging state, the voltage of the first DC port, the voltage of the fourth DC port, and the turns ratio of the first transformer includes: When the ratio between the second voltage and the first voltage is greater than the turns ratio of the first secondary coil and the first primary coil of the first transformer, the first voltage conversion module is controlled to switch to the step-down conversion state; when the ratio between the second voltage and the first voltage is less than the turns ratio of the first secondary coil and the first primary coil of the first transformer, the first voltage conversion module is controlled to switch to the step-up conversion state.

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