DCDC bidirectional charging and discharging circuit and device

Abstract

The utility model discloses a DCDC bidirectional charging and discharging circuit and device. The DCDC bidirectional charging and discharging circuit comprises a first bidirectional inversion module, a transformer, a switch module and a second bidirectional inversion module. The first bidirectional inversion module carries out bidirectional conversion on DC voltage and AC voltage. The transformer comprises a primary coil and a secondary coil. The secondary coil comprises a first end, a second end and at least one center tap located between the first end and the second end. The switch module adjusts the turn ratio of the transformer, and cooperates with the transformer to carry out boost or buck conversion on the AC voltage. The second bidirectional inversion module carries out bidirectional conversion on the AC voltage and the DC voltage. According to the technical scheme, efficient voltage conversion, turn ratio adjustment of the transformer and flexible control of the switch module are realized, the problem of mismatching between photovoltaic input voltage and battery voltage is effectively solved, and the problem of battery overcurrent protection caused by overlarge voltage difference in a traditional system is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of photoelectric sensing, in particular to a DCDC bidirectional charging and discharging circuit and device. Background Art

[0002] With the rapid development of renewable energy, the integration of photovoltaic power generation and energy storage systems has become a key means of achieving efficient energy utilization. In traditional photovoltaic energy storage systems, the photovoltaic input is boosted by a boost circuit and then connected to the DC bus. The photovoltaic circuit then outputs a sinusoidal current for use by the power grid or load. Simultaneously, the system controls the battery charging current through the buck-boost circuit, achieving efficient energy scheduling between photovoltaic power generation, batteries, and loads. However, during rapid charging conversions in traditional systems, the buck-boost circuit is susceptible to higher current surges, increasing the risk of circuit damage, especially during high-frequency conversions and load transfers. Furthermore, the buck-boost circuit has a complex structure and is extremely expensive, increasing the overall hardware cost and access maintenance of the system.

[0003] To address these issues, one solution proposes eliminating the buck-boost circuit and instead adjusting the DC bus voltage to achieve battery charging, discharging, and energy scheduling. In this solution, the input voltage is boosted via the boost circuit and then connected directly to the bus, through which the battery is charged and discharged. However, while this solution simplifies circuit design and reduces costs, the elimination of the buck-boost circuit makes the system susceptible to battery overcurrent protection issues when faced with a wider input voltage range, especially when the input voltage is high and the battery voltage is low. Therefore, how to resolve the mismatch between the photovoltaic input voltage and the battery voltage while eliminating the buck-boost circuit has become a key technical issue in the design of photovoltaic energy storage systems. Utility Model Content

[0004] The embodiments of the present invention provide a DCDC bidirectional charging and discharging circuit and device to solve the above technical problems.

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

[0006] A first bidirectional inverter module performs bidirectional conversion between DC voltage and AC voltage;

[0007] a transformer comprising a primary coil and a secondary coil, wherein the primary coil is connected to the first bidirectional inverter module, and the secondary coil comprises a first end, a second end, and at least one intermediate tap located between the first end and the second end;

[0008] a switch module comprising a common terminal and a plurality of switching terminals, wherein the plurality of switching terminals are connected in a one-to-one correspondence with the first terminal and the intermediate tap of the secondary coil, so as to adjust the turns ratio of the transformer and cooperate with the transformer to step up or step down the AC voltage;

[0009] The second bidirectional inverter module is connected to the second end of the secondary coil and the common end of the switch module respectively, so as to perform bidirectional conversion between AC voltage and DC voltage.

[0010] Optionally, the first bidirectional inverter module converts the first DC voltage into a first AC voltage;

[0011] The transformer and the switch module convert the first AC voltage into a second AC voltage;

[0012] The second bidirectional inverter module converts the second AC voltage into a second DC voltage.

[0013] Optionally, the second bidirectional inverter module converts the third DC voltage into a third AC voltage;

[0014] The transformer and the switch module convert the third AC voltage into a fourth AC voltage;

[0015] The first bidirectional inverter module converts the fourth AC voltage into a fourth DC voltage.

[0016] Optionally, the first bidirectional inverter module includes a first end, a second end, a third end, and a fourth end, and the second bidirectional inverter module includes a first end, a second end, a third end, and a fourth end;

[0017] The first end and the second end of the first bidirectional inverter module are used to receive or output a DC voltage;

[0018] The third end of the first bidirectional inverter module is connected to the first end of the primary coil, the fourth end of the first bidirectional inverter module is connected to the second end of the primary coil, and the third end and the fourth end of the first bidirectional inverter module are used to receive or output AC voltage;

[0019] The first end of the second bidirectional inverter module is connected to the common end of the switch module, the second end of the second bidirectional inverter module is connected to the second end of the secondary coil, and the first end and the second end of the second bidirectional inverter module are used to receive or output AC voltage;

[0020] The third terminal and the fourth terminal of the second bidirectional inverter module are used to receive or output a DC voltage.

[0021] Optionally, the first bidirectional inverter module includes a first MOS transistor, a second MOS transistor, a third MOS transistor and a fourth MOS transistor; the drain of the first MOS transistor and the drain of the second MOS transistor are commonly connected to the first end of the first bidirectional inverter module, the source of the third MOS transistor and the source of the fourth MOS transistor are commonly connected to the second end of the first bidirectional inverter module, the source of the first MOS transistor and the drain of the third MOS transistor are commonly connected to the third end of the first bidirectional inverter module, and the source of the second MOS transistor and the drain of the fourth MOS transistor are commonly connected to the fourth end of the first bidirectional inverter module.

[0022] Optionally, the second bidirectional inverter module includes a first IGBT module, a second IGBT module, a third IGBT module and a fourth IGBT module; the second end of the first IGBT module and the first end of the second IGBT module are connected together as the second end of the second bidirectional inverter module, the second end of the third IGBT module and the first end of the fourth IGBT module are connected together as the first end of the second bidirectional inverter module, the first end of the first IGBT module and the first end of the third IGBT module are connected together as the third end of the second bidirectional inverter module, and the second end of the second IGBT module and the second end of the fourth IGBT module are connected together as the fourth end of the second bidirectional inverter module.

[0023] A second aspect of an embodiment of the present invention provides a DCDC bidirectional charge and discharge device, comprising: the DCDC bidirectional charge and discharge circuit described in the first aspect and a control module, wherein the control module is connected to the control end of the switch module.

[0024] Optionally, the DCDC bidirectional charge and discharge device further includes a first light-emitting diode and a first photodiode, the first light-emitting diode is connected to the second bidirectional inverter module, the first photodiode is connected to the control module, and the control module is also connected to the control end of the first bidirectional inverter module.

[0025] Optionally, the DCDC bidirectional charge and discharge device also includes a second light-emitting diode, a second photodiode and an operational amplifier, the second light-emitting diode is connected to the input end of the first bidirectional inverter module, the first input end of the operational amplifier is connected to the first photodiode, the second input end of the operational amplifier is connected to the second photodiode, the output end of the operational amplifier is connected to the control module, and the control module is also connected to the control end of the second bidirectional inverter module.

[0026] The technical effect of the embodiment of the utility model is as follows: the technical solution realizes efficient voltage conversion and energy scheduling by adopting a bidirectional inverter module, a transformer and a switch module, and the turns ratio adjustment of the transformer and the flexible control of the switch module effectively solve the mismatch problem between the photovoltaic input voltage and the battery voltage, and avoids the battery overcurrent protection problem caused by excessive voltage difference in traditional systems. By simplifying circuit design, improving system reliability and reducing costs, the solution provides a more efficient, flexible and economical charging and discharging solution for photovoltaic energy storage systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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.

[0028] Figure 1 This is a structural diagram of a DCDC bidirectional charge and discharge circuit provided in Example 1 of the present utility model;

[0029] Figure 2 This is a circuit diagram of a DCDC bidirectional charge and discharge circuit provided in Example 1 of the present utility model;

[0030] Figure 3 This is a schematic diagram of the first structure of a DCDC bidirectional charge and discharge device provided in the second embodiment of the present utility model;

[0031] Figure 4 This is a circuit diagram of a DCDC bidirectional charging and discharging device provided in Example 2 of the present utility model;

[0032] Figure 5 This is a second structural diagram of a DCDC bidirectional charge and discharge device provided in the second embodiment of the present utility model;

[0033] Figure 6 This is a third structural diagram of a DCDC bidirectional charge and discharge device provided in the second embodiment of the present utility model;

[0034] In the figure: 101, a first bidirectional inverter module; 102, a transformer; 103, a switch module; 104, a second bidirectional inverter module; 105, a control module; 106, a first light-emitting diode; 107, a first photodiode; 108, a second light-emitting diode; 109, a second photodiode. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] It should be understood that the present invention can be implemented 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 present 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.

[0037] 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 are 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. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer, or part discussed below may be represented as a second element, component, region, layer, or part.

[0038] 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 also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "including", 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.

[0039] In order to fully understand the present invention, the following description will provide detailed structures and steps to illustrate the technical solutions proposed by the present invention. The 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 implementation methods.

[0040] Example 1

[0041] This embodiment provides a DCDC bidirectional charging and discharging circuit, such as Figure 1 As shown, including:

[0042] A first bidirectional inverter module 101 performs bidirectional conversion between DC voltage and AC voltage;

[0043] The transformer 102 includes a primary coil and a secondary coil, wherein the primary coil is connected to the first bidirectional inverter module 101, and the secondary coil includes a first end, a second end, and at least one intermediate tap located between the first end and the second end;

[0044] A switch module 103 includes a common terminal and multiple switching terminals, each of which is connected to the first terminal and the middle tap of the secondary coil in a one-to-one correspondence to adjust the turns ratio of the transformer 102 and cooperate with the transformer 102 to step up or down the AC voltage;

[0045] The second bidirectional inverter module 104 is connected to the second end of the secondary coil and the common end of the switch module 103 respectively, so as to perform bidirectional conversion between AC voltage and DC voltage.

[0046] When the DCDC bidirectional charge and discharge circuit is charging, the first bidirectional inverter module 101 converts the first DC voltage into a first AC voltage; the transformer 102 and the switch module 103 convert the first AC voltage into a second AC voltage; and the second bidirectional inverter module 104 converts the second AC voltage into a second DC voltage.

[0047] When the DCDC bidirectional charge and discharge circuit is discharging, the second bidirectional inverter module 104 converts the third DC voltage into a third AC voltage; the transformer 102 and the switch module 103 convert the third AC voltage into a fourth AC voltage; and the first bidirectional inverter module 101 converts the fourth AC voltage into a fourth DC voltage.

[0048] The primary function of the first bidirectional inverter module 101 is to convert DC voltage to AC voltage. It can convert DC voltage from a DC power source into AC voltage for energy conversion via transformer 102. It can also convert the AC voltage output by transformer 102 into DC voltage for discharging or charging the battery. When in the charging state, the first bidirectional inverter module 101 converts the first DC voltage from a DC power source (such as a photovoltaic power generation system or the power grid) into a first AC voltage and transmits it to the primary coil of transformer 102. Transformer 102 performs step-up and step-down conversion of the charging voltage in this circuit. Using the turns ratio of its primary and secondary coils, transformer 102 converts the AC voltage output by the first coil to an appropriate voltage level for charging or discharging. The primary coil of transformer 102 receives the first AC voltage output by the first bidirectional inverter module 101 and converts it to a second AC voltage via its secondary coil. The secondary coil of transformer 102 also receives the third AC voltage output by the second bidirectional inverter module 104 and converts it to a fourth AC voltage via the primary coil. The switch module 103 adjusts the turns ratio of the transformer 102 by switching the multiple tap ends of the secondary coil, thereby achieving step-up or step-down conversion of the AC power. The switch module 103 can dynamically select the number of turns of the secondary coil of the transformer 102 to adapt to different turns-abundant requirements. During the charging process, the switch module 103 adjusts the output voltage of the secondary coil of the transformer 102 to a suitable voltage according to the appropriate turns ratio required, so that the second bidirectional inverter module 104 can convert it to a second DC voltage. During the discharge process, the switch module 103 adjusts the turns ratio to ensure that the output voltage of the secondary coil is the third AC voltage, promoting the conversion of the first bidirectional inverter module 101. The main function of the second bidirectional inverter module 104 is to achieve conversion between AC voltage and DC voltage, converting the AC voltage output by the secondary coil of the transformer 102 into DC voltage (charging mode) or converting the DC voltage into DC voltage AC voltage (discharging mode).

[0049] The technical effect of the technical solution provided in the first embodiment is that: this technical solution realizes efficient voltage conversion and energy scheduling by adopting a bidirectional inverter module, a transformer, and a switch module. The transformer turns ratio adjustment and flexible control of the switch module effectively solve the mismatch problem between the photovoltaic input voltage and the battery voltage, and avoids the battery overcurrent protection problem caused by excessive voltage difference in traditional systems. By simplifying circuit design, improving system reliability, and reducing costs, this solution provides a more efficient, flexible, and economical charging and discharging solution for photovoltaic energy storage systems.

[0050] As an implementation method, Figure 2As shown, the first bidirectional inverter module 101 includes a first end, a second end, a third end and a fourth end, and the second bidirectional inverter module 104 includes a first end, a second end, a third end and a fourth end; the first end and the second end of the first bidirectional inverter module 101 are used to receive or output a DC voltage; the third end of the first bidirectional inverter module 101 is connected to the first end of the primary coil, the fourth end of the first bidirectional inverter module 101 is connected to the second end of the primary coil, and the third end and the fourth end of the first bidirectional inverter module 101 are used to receive or output an AC voltage; the first end of the second bidirectional inverter module 104 is connected to the common end of the switch module 103, the second end of the second bidirectional inverter module 104 is connected to the second end of the secondary coil, and the first end and the second end of the second bidirectional inverter module 104 are used to receive or output an AC voltage; the third end and the fourth end of the second bidirectional inverter module 104 are used to receive or output a DC voltage.

[0051] Specifically, 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 form a first terminal 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 form a second terminal 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 form a third terminal 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 form a fourth terminal of the first bidirectional inverter module 101.

[0052] The first and third MOS transistors Q1 and Q3 form the first bridge arm, while the second and fourth MOS transistors Q2 and Q4 form the second bridge arm, working together with the first bridge arm to perform inversion and rectification operations. The operating states of the second and fourth MOS transistors Q2 and Q4 complement those of the first and third MOS transistors Q1 and Q3, ensuring bidirectional energy flow in the inverter. In charging mode, the first and third MOS transistors Q1 and Q3, and the second and fourth MOS transistors Q2 and Q4, alternately turn on and off to convert DC power into AC power. By controlling the switching states of the bridge arms, inversion is achieved, outputting AC power to a load or the primary side of a transformer. In discharging mode, the bridge arm components operate in reverse, with the first and third MOS transistors Q1 and Q3, and the second and fourth MOS transistors Q2 and Q4 turning on and off accordingly, receiving AC power and rectifying it to DC power. In this mode, the system outputs DC power to a battery or DC load, achieving energy storage or power supply.

[0053] As an embodiment, the second bidirectional inverter module 104 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 as the second end of the second bidirectional inverter module 104, the second end of the third IGBT module Q7 and the first end of the fourth IGBT module Q8 are connected together as the first end of the second bidirectional inverter module 104, the first end of the first IGBT module Q5 and the first end of the third IGBT module Q7 are connected together as the third end of the second bidirectional inverter module 104, and the second end of the second IGBT module Q6 and the second end of the fourth IGBT module Q8 are connected together as the fourth end of the second bidirectional inverter module 104.

[0054] The first IGBT module Q5 and the second IGBT module Q6 form one arm of the second bidirectional inverter module 104, while the third IGBT module Q7 and the fourth IGBT module Q8 form the other arm of the second bidirectional inverter module 104, working together with the first IGBT module Q5 and the second IGBT module Q6 to complete the inversion operation. In charging mode, the first IGBT module Q5 and the second IGBT module Q6, the third IGBT module Q7, and the fourth IGBT module Q8 work together to convert the AC voltage from the secondary coil of the transformer 102 into a DC voltage. The converted DC voltage is output to a DC load or energy storage device via the third and fourth terminals, achieving energy recovery or output. In discharging mode, the first IGBT module Q5 and the second IGBT module Q6, the third IGBT module Q7, and the fourth IGBT module Q8 work alternately, converting the DC voltage from the DC power supply or battery into an AC voltage through the inversion process. The converted AC voltage is transmitted to the secondary coil via the first and second terminals for further transmission or use.

[0055] Example 2

[0056] This embodiment 2 provides a DCDC bidirectional charging and discharging device, such as Figure 3 As shown, it includes: the DCDC bidirectional charge and discharge circuit of embodiment 1 and a control module 105 , and the control module 105 is connected to the control end of the switch module 103 .

[0057] The switch module 103 adjusts the turns ratio by controlling the tap of the secondary winding of the transformer 102, thereby adjusting the step-up or step-down output of the transformer 102. The switch module 103 has multiple switching terminals, each connected to a different tap of the secondary winding. Voltage adjustment is achieved by selecting the appropriate tap position.

[0058] The control module coordinates the operation of each module. By connecting to the control terminal of the switch module 103, it adjusts the operating state of the switch module 103 and selects the appropriate turns ratio to ensure the system's efficient and stable power conversion process in different operating modes. In charging mode, the control module 105 monitors the input voltage and current parameters, calculates the required turns ratio of the transformer 102, and controls the switch module 103 to select the appropriate tap position to ensure that the output voltage meets the charging requirements. In discharge mode, the control module adjusts the turns ratio selection of the switch module 103 and the operating state of the power discharge module based on the load demand or grid parameters to ensure that the energy released from the energy storage device can be effectively transmitted to the load or grid, ensuring stable output voltage and current.

[0059] As an example, Figure 4 As shown, the working process of this embodiment 2 is as follows:

[0060] 1. When Vbus / Vbat is less than N3 / N1, relay K1 switches to N3 winding. When charging, the BOOST circuit controls the BUS voltage to be greater than Vbat×(N3 / N1). When discharging, the BUS voltage is adjusted to be less than Vbat×(N3 / N1) for discharge, completing the entire charge and discharge logic.

[0061] 2. When Vbus / Vbat is greater than N3 / N1 and less than (N3+N2) / N1, relay K1 switches to N3+N2 winding. When charging, the BOOST circuit controls the BUS voltage to be greater than Vbat×((N3+N2) / N1). When discharging, the BUS voltage is adjusted to be less than Vbat×((N3+N2) / N1) for discharge, completing the entire charge and discharge logic.

[0062] As an implementation method, Figure 5 As shown, the DCDC bidirectional charge and discharge device also includes a first light-emitting diode 106 and a first photodiode 107. The first light-emitting diode 106 is connected to the second bidirectional inverter module, and the first photodiode 107 is connected to the control module 105. The control module 105 is also connected to the control end of the first bidirectional inverter module 101.

[0063] The first light-emitting diode 106 is connected to the output of the second bidirectional inverter module 104 and converts the voltage signal from the second bidirectional inverter module 104 into an optical signal. During system operation, the first light-emitting diode 106 emits an optical signal based on the operating status of the second bidirectional inverter module 104, indicating changes in the output voltage. The first photodiode 107 is connected to the control module 105 and receives the optical signal emitted by the first light-emitting diode 106 and converts it into a current signal. The first photodiode 107 can detect changes in the light intensity of the first light-emitting diode 106, which reflects fluctuations in the output voltage or current of the inverter module. The first photodiode 107 converts these changes into an electrical signal and transmits it to the control module 105 as a feedback signal, allowing the control module 105 to determine whether the system is operating within the set voltage or current range. The control module 105 receives the current feedback signal from the first photodiode 107 and adjusts the operating status of the first bidirectional inverter module 101 based on this signal. The control module 105 primarily achieves dynamic voltage or current regulation by adjusting the PWM duty cycle or switching frequency of the inverter module. If the control module 105 detects that the output voltage or current deviates from the set value (for example, the voltage is too high or too low), it will automatically adjust the operating parameters of the inverter module until the output returns to the normal range. The first bidirectional inverter module 101 is used to perform bidirectional conversion between DC voltage and AC voltage, receive adjustment instructions (such as PWM signals or switching frequency adjustment signals) from the control module 105, and adjust the output voltage according to the current needs of the system. In charging mode, the DC voltage from the DC power supply is converted into AC voltage and transmitted to the transformer; in discharging mode, the AC voltage of the transformer is converted into DC voltage and power is supplied to the battery or load. The first photodiode 107 can be used not only to detect the output voltage of the inverter module, but also to detect its output current. By detecting changes in the output current through the first photodiode 107, the control module 105 can adjust the output current of the inverter in real time. In particular, when the load changes, the current feedback signal can promptly reflect the changes in load demand. The control module adjusts the output current based on the feedback information to avoid overcurrent or insufficient current.

[0064] The technical effect of this embodiment is that: through the photoelectric coupling method of the first light-emitting diode and the first photodiode, electrical isolation is achieved, electromagnetic interference is avoided, and real-time monitoring and feedback adjustment are achieved. The control module adjusts the PWM duty cycle or switching frequency of the first bidirectional inverter module by real-time monitoring of the feedback signal of the first photodiode to ensure that the system output voltage and current are within the set range, thereby improving the adaptability and dynamic response capability of the system. The first photodiode can also detect current changes to ensure that the inverter module can quickly adjust the output current when the load fluctuates, prevent overcurrent or insufficient current, and improve the protection and adaptability of the system. Through real-time monitoring and feedback control of the first light-emitting diode and the first photodiode, the system achieves precise regulation of voltage and current, greatly improving the efficiency, stability and responsiveness of the DCDC bidirectional charging and discharging device.

[0065] As an implementation method, Figure 6 As shown, the DCDC bidirectional charge and discharge device also includes a second light-emitting diode 108, a second photodiode 109 and an operational amplifier 110. The second light-emitting diode 108 is connected to the input end of the first bidirectional inverter module 101, the first input end of the operational amplifier 110 is connected to the first photodiode 109, the second input end of the operational amplifier 110 is connected to the second photodiode 108, and the output end of the operational amplifier 110 is connected to the control module 105. The control module 105 is also connected to the control end of the second bidirectional inverter module 104.

[0066] The main function of the second LED 108 is to emit a light signal corresponding to the input state based on changes in the input voltage or current of the first bidirectional inverter module 101. This light signal is used to characterize the electrical characteristics of the input terminal (such as the magnitude and change of the voltage or current). When the first bidirectional inverter module 101 receives an input voltage or current, the second LED 108 emits a corresponding light signal, the intensity of which is proportional to the input voltage or current. This light signal is used to convey the input state and cooperates with subsequent photodiodes for signal processing. The second photodiode 109 is used to receive the light signal from the second LED 108 and convert it into a corresponding current signal. This current signal represents the voltage or current change at the input terminal of the first bidirectional inverter module 101 and serves as one of the system's feedback signals. The second photodiode 109 receives the light signal emitted by the second LED 108, converts it into a current signal, and transmits it to the second input terminal of the operational amplifier 110. The first photodiode 107 receives the light signal emitted by the first LED 106, indicating the output state of the second bidirectional inverter module 104. By converting the optical signal into a current signal, the first photodiode 107 provides the control module 105 with an output feedback signal. The first photodiode 107 receives the optical signal from the first light-emitting diode 106, converts it into a current signal, and transmits it to the first input of the operational amplifier 110. This signal reflects the output voltage or current state of the second bidirectional inverter module 104 and is a key parameter for control and regulation. The operational amplifier 110 plays a core role in signal processing in the system. By performing differential processing on the two feedback signals, it determines the difference between the system input and output. This difference signal is used to drive the control module 110 and adjust the operating state of the inverter module. The operational amplifier 110 receives feedback signals from the first photodiode 107 and the second photodiode 109, representing the output and input states of the system, respectively. The operational amplifier 110 compares the two signals (differential operation) and outputs a signal representing the difference between the system input and output. The output signal is transmitted to the control module 105, helping the system adjust the inverter operating parameters to ensure stable operation. The control module 105 adjusts the operating states (e.g., PWM duty cycle or switching frequency) of the first and second bidirectional inverter modules 101, 104 in real time based on the output signal from the operational amplifier 110. It is responsible for performing closed-loop regulation based on the feedback signal to ensure that the system's output voltage or current meets the set target value. The control module 105 receives the output signal from the operational amplifier 110, which indicates the difference between the system's input and output states. Based on this difference signal, the control module 105 adjusts the operating states of the first and second bidirectional inverter modules 101, 104 to stabilize their outputs within the target range.A closed-loop control is formed between the control module 105 and the first bidirectional inverter module 101 and the second bidirectional inverter module 104 to continuously monitor and dynamically adjust the output of the system.

[0067] The technical effect of this embodiment is that the second light-emitting diode cooperates with the second photodiode to monitor the input end of the first bidirectional inverter module; the first light-emitting diode cooperates with the first photodiode to monitor the output end of the second bidirectional inverter module. The optoelectronic coupling method effectively isolates signal transmission, reduces electromagnetic interference, and improves signal stability. The operational amplifier calculates the difference between the input and output states of the system by processing the feedback signals from the two photodiodes and transmits the result to the control module to achieve precise closed-loop control. The control module adjusts the operating state of the second bidirectional inverter module in real time based on the output signal of the operational amplifier, ensuring that the output voltage and current of the system are stable within the set range, thereby enhancing the dynamic response capability and adaptability of the system. Through the coordinated operation of these modules, the system achieves precise monitoring and dynamic adjustment of input and output, greatly improving energy conversion efficiency, stability and anti-interference ability, and ensuring that an efficient charging and discharging process is maintained under different load or input conditions.

[0068] 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 DCDC bidirectional charge and discharge circuit, characterized in that: include: A first bidirectional inverter module performs bidirectional conversion between DC voltage and AC voltage; a transformer comprising a primary coil and a secondary coil, wherein the primary coil is connected to the first bidirectional inverter module, and the secondary coil comprises a first end, a second end, and at least one intermediate tap located between the first end and the second end; a switch module comprising a common terminal and a plurality of switching terminals, wherein the plurality of switching terminals are connected in a one-to-one correspondence with the first terminal and the intermediate tap of the secondary coil, so as to adjust the turns ratio of the transformer and cooperate with the transformer to step up or step down the AC voltage; The second bidirectional inverter module is connected to the second end of the secondary coil and the common end of the switch module respectively, so as to perform bidirectional conversion between AC voltage and DC voltage.

2. The DCDC bidirectional charge and discharge circuit according to claim 1, wherein: The first bidirectional inverter module converts the first DC voltage into a first AC voltage; The transformer and the switch module convert the first AC voltage into a second AC voltage; The second bidirectional inverter module converts the second AC voltage into a second DC voltage.

3. The DCDC bidirectional charge and discharge circuit according to claim 1, wherein: The second bidirectional inverter module converts the third DC voltage into a third AC voltage; The transformer and the switch module convert the third AC voltage into a fourth AC voltage; The first bidirectional inverter module converts the fourth AC voltage into a fourth DC voltage.

4. The DCDC bidirectional charge and discharge circuit according to claim 1, wherein: The first bidirectional inverter module includes a first end, a second end, a third end, and a fourth end; the second bidirectional inverter module includes a first end, a second end, a third end, and a fourth end; The first end and the second end of the first bidirectional inverter module are used to receive or output a DC voltage; The third end of the first bidirectional inverter module is connected to the first end of the primary coil, the fourth end of the first bidirectional inverter module is connected to the second end of the primary coil, and the third end and the fourth end of the first bidirectional inverter module are used to receive or output AC voltage; The first end of the second bidirectional inverter module is connected to the common end of the switch module, the second end of the second bidirectional inverter module is connected to the second end of the secondary coil, and the first end and the second end of the second bidirectional inverter module are used to receive or output AC voltage; The third terminal and the fourth terminal of the second bidirectional inverter module are used to receive or output a DC voltage.

5. The DCDC bidirectional charge and discharge circuit according to claim 4, wherein: The first bidirectional inverter module includes a first MOS transistor, a second MOS transistor, a third MOS transistor, and a fourth MOS transistor; the drain of the first MOS transistor and the drain of the second MOS transistor are commonly connected to the first end of the first bidirectional inverter module, the source of the third MOS transistor and the source of the fourth MOS transistor are commonly connected to the second end of the first bidirectional inverter module, the source of the first MOS transistor and the drain of the third MOS transistor are commonly connected to the third end of the first bidirectional inverter module, and the source of the second MOS transistor and the drain of the fourth MOS transistor are commonly connected to the fourth end of the first bidirectional inverter module.

6. The DCDC bidirectional charge and discharge circuit according to claim 4, wherein: The second bidirectional inverter module includes a first IGBT module, a second IGBT module, a third IGBT module and a fourth IGBT module; the second end of the first IGBT module and the first end of the second IGBT module are connected together to form the second end of the second bidirectional inverter module, the second end of the third IGBT module and the first end of the fourth IGBT module are connected together to form the first end of the second bidirectional inverter module, the first end of the first IGBT module and the first end of the third IGBT module are connected together to form the third end of the second bidirectional inverter module, and the second end of the second IGBT module and the second end of the fourth IGBT module are connected together to form the fourth end of the second bidirectional inverter module.

7. A DCDC bidirectional charge and discharge device, characterized in that: include: The DCDC bidirectional charge and discharge circuit and control module according to any one of claims 1 to 6, wherein the control module is connected to the control end of the switch module.

8. The DCDC bidirectional charge and discharge device according to claim 7, wherein: The DCDC bidirectional charge and discharge device further includes a first light emitting diode and a first photodiode. The first light emitting diode is connected to the second bidirectional inverter module. The first photodiode is connected to the control module. The control module is also connected to the control end of the first bidirectional inverter module.

9. The DCDC bidirectional charge and discharge device according to claim 8, characterized in that: The DCDC bidirectional charge and discharge device also includes a second light-emitting diode, a second photodiode and an operational amplifier. The second light-emitting diode is connected to the input end of the first bidirectional inverter module, the first input end of the operational amplifier is connected to the first photodiode, the second input end of the operational amplifier is connected to the second photodiode, and the output end of the operational amplifier is connected to the control module. The control module is also connected to the control end of the second bidirectional inverter module.

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