DCDC bidirectional charging and discharging device and system

Abstract

The present invention discloses a DC / DC bidirectional charging and discharging device and system. The DC / DC bidirectional charging and discharging device includes a first bidirectional inverter module, a first transformer, a second bidirectional inverter module, a first auxiliary power supply module, a second auxiliary power supply module, and a first control module. The first power supply module outputs a first DC voltage to the second auxiliary power supply module; the first auxiliary power supply module converts the second DC voltage according to a first control signal and outputs a third DC voltage to the second auxiliary power supply module; the second auxiliary power supply module converts the first DC voltage or the third DC voltage according to a second control signal and outputs a startup voltage to the first control module. By providing two-stage auxiliary power supply modules, the present technical solution enables the system to be autonomously started when voltage is present in the battery on either side, thereby solving the problem that existing isolated bidirectional DC / CDC converters cannot start when fed by a low-voltage battery or in a dormant state.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage inverters, and in particular to a DCDC bidirectional charging and discharging device and system. Background Art

[0002] With the rapid development of new energy vehicles and smart grid technologies, bidirectional DC-DC converters have become an important interface for energy exchange between electric vehicles and external power grids, and are widely used in scenarios such as on-board charging systems, V2H (Vehicle to Home), and V2G (Vehicle to Grid). To meet the energy conversion requirements between high-voltage and low-voltage batteries, bidirectional DC-DC systems must not only support forward and reverse energy flow but also be able to achieve autonomous startup when powered by either battery. Existing technologies primarily include the following three solutions:

[0003] 1. Non-isolated bidirectional DC-DC converters: This solution offers a simple structure, low cost, and easy development. However, because the input and output are not electrically isolated, a short circuit or overload on one side can quickly transmit the fault current to the other side, potentially causing system-level damage. This poses a serious safety hazard and makes it difficult to pass automotive or grid safety certifications.

[0004] 2. Isolated bidirectional DC-DC converters: These achieve electrical isolation of input and output through a first transformer, offering enhanced safety. However, most of these solutions can only start the system via the low-voltage auxiliary power supply unit. When the low-voltage battery is severely depleted or dormant, the power supply circuit cannot be activated. This results in the system being unable to activate despite sufficient power on the high-voltage side, hindering vehicle startup and functional recovery.

[0005] 3. Multi-output auxiliary power supply solution: Some systems attempt to incorporate multiple output power supplies to power various subsystems to meet auxiliary power requirements. However, due to their crude structural design, when the low-voltage battery voltage is too low or completely lost, the system cannot be activated autonomously, requiring external equipment or manual operation for power startup. This increases user difficulty and maintenance costs, and reduces the overall reliability and practicality of the system. Summary of the Invention

[0006] The embodiments of the present invention provide a DCDC bidirectional charging and discharging device and system to solve the above technical problems.

[0007] A first aspect of an embodiment of the present invention provides a DC-DC bidirectional charging and discharging device, comprising:

[0008] a first bidirectional inverter module, one end of which is connected to the first power module and performs bidirectional conversion between a first DC voltage output or received by the first power module and a first AC voltage;

[0009] a first transformer comprising a primary coil and a secondary coil, wherein the primary coil is connected to the other end of the first bidirectional inverter module;

[0010] a second bidirectional inverter module, one end of which is connected to the secondary coil and the other end of which is connected to the second power supply module, and bidirectionally converts a second DC voltage output or received by the second power supply module into a second AC voltage, wherein the first DC voltage is lower than the second DC voltage;

[0011] a first auxiliary power supply module, one end of which is connected to the second power supply module and the other end of which is connected to the first power supply module;

[0012] a second auxiliary power supply module, one end of which is connected to the first power supply module and the first auxiliary power supply module respectively;

[0013] a first control module, which is respectively connected to the control end of the first bidirectional inverter module, the control end of the second bidirectional inverter module, and the other end of the second auxiliary power supply module;

[0014] The first power supply module outputs a first DC voltage to the second auxiliary power supply module;

[0015] The first auxiliary power supply module converts the second DC voltage according to the first control signal and outputs a third DC voltage to the second auxiliary power supply module;

[0016] The second auxiliary power supply module converts the first DC voltage or the third DC voltage according to a second control signal and outputs a startup voltage to the first control module.

[0017] Optionally, the second auxiliary power supply module converts the larger one of the first DC voltage and the third DC voltage according to a second external control signal and outputs a starting voltage to the first control module.

[0018] Optionally, the first auxiliary power supply module includes a second transformer, a first rectifier and filter module, and a second control module, the first end of the primary coil of the second transformer is connected to the positive pole of the second power module, the second end of the primary coil of the second transformer is connected to one end of the second control module, and the other end of the second control module is connected to the negative pole of the second power module, the first end of the secondary coil of the second transformer is connected to the first input end of the first rectifier and filter module, the second end of the secondary coil of the second transformer is connected to the second input end of the first rectifier and filter module, the first output end of the first rectifier and filter module is connected to the positive pole of the first power module, and the second output end of the first rectifier and filter module is connected to the negative pole of the first power module;

[0019] The second control module controls the second transformer to convert the second DC voltage into a second AC voltage according to the first control signal;

[0020] The first rectifying and filtering module rectifies and filters the second alternating current voltage and outputs a third direct current voltage.

[0021] Optionally, the second control module includes:

[0022] A first enabling unit, configured to receive a first control signal and output a first enabling signal;

[0023] a first control unit, an input end of which is connected to the output end of the first enabling unit, and outputs a first PWM control signal according to the first enabling signal;

[0024] A first power unit, whose control end is connected to the output end of the first control unit, whose first output end is one end of the second control module, and whose second output end is the other end of the second control module, is used to convert the second DC voltage into a third AC voltage according to the first PWM control signal.

[0025] Optionally, the first rectifier and filter module includes a first diode, a second diode and a first capacitor, the anode of the first diode is the first input end of the first rectifier and filter module, the cathode of the first diode is respectively connected to the anode of the second diode and one end of the first capacitor, the cathode of the second diode is the first output end of the first rectifier and filter module, and the other end of the first capacitor is respectively the second input end and the second output end of the first rectifier and filter module.

[0026] Optionally, the second auxiliary power supply module includes a third transformer, a second rectifier and filter module, and a third control module, the first end of the primary coil of the third transformer is connected to the positive pole of the first power module, the second end of the primary coil of the third transformer is connected to one end of the third control module, and the other end of the third control module is connected to the negative pole of the first power module, the first end of the secondary coil of the third transformer is connected to the first input end of the second rectifier and filter module, the second end of the secondary coil of the third transformer is connected to the second input end of the second rectifier and filter module, the first output end of the second rectifier and filter module is connected to the first power input end of the first control module, and the second output end of the second rectifier and filter module is connected to the second power input end of the first control module;

[0027] The third control module controls the third transformer to convert the third DC voltage into a fourth AC voltage according to the second control signal;

[0028] The second rectifying and filtering module rectifies and filters the fourth AC voltage and then outputs a startup voltage.

[0029] Optionally, the third control module includes:

[0030] A second enabling unit, configured to receive a second control signal and output a second enabling signal;

[0031] a second control unit, an input end of which is connected to the output end of the second enabling unit, and outputs a second PWM control signal according to the second enabling signal;

[0032] A second power unit, whose control end is connected to the output end of the second control unit, whose first output end is one end of the third control module, and whose second output end is the other end of the third control module, is used to convert the third DC voltage into a fifth AC voltage according to the second PWM control signal.

[0033] Optionally, the second rectifier and filter module includes a third diode and a second capacitor, the anode of the third diode is the first input end of the second rectifier and filter module, the cathode of the third diode and one end of the second capacitor are connected together as the first output end of the second rectifier and filter module, and the other end of the second capacitor is the second input end and the second output end of the second rectifier and filter module respectively.

[0034] Optionally, the DCDC bidirectional charge and discharge device further includes a sixth diode, the anode of the sixth diode is connected to the positive electrode of the first power module, and the cathode of the sixth diode is connected to the first end of the primary coil of the third transformer.

[0035] A second aspect of an embodiment of the present invention provides a DCDC bidirectional charge and discharge system, comprising the DCDC bidirectional charge and discharge device according to the first aspect, a first power module, and a second power module.

[0036] The technical effects of the embodiments of the present invention are as follows: by providing a two-stage auxiliary power supply module, the system can be autonomously started when there is voltage in the battery on either side, thereby solving the problem that the existing isolated bidirectional DCDC converter cannot start when fed by a low-voltage battery or in a dormant state; the first auxiliary power supply module uses the high-voltage side power energy to supply power to the second auxiliary power supply module, and the second auxiliary power supply module is combined to convert the voltage from either side to output the starting voltage, thereby ensuring that the first control module has a stable power-on capability, realizing bidirectional self-activation startup of the system, improving the reliability and practicality of the system, and effectively meeting the application requirements of multiple scenarios such as on-board charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] 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.

[0038] Figure 1 This is a structural diagram of a DCDC bidirectional charge and discharge device provided in Example 1 of the present invention;

[0039] Figure 2 This is a structural diagram of a first auxiliary power supply module in a DCDC bidirectional charge and discharge device provided in Example 1 of the present invention;

[0040] Figure 3 This is a structural diagram of a second control module in a first auxiliary power supply module in a DCDC bidirectional charge and discharge device provided in Example 1 of the present invention;

[0041] Figure 4 This is a structural diagram of a second auxiliary power supply module in a DCDC bidirectional charge and discharge device provided in Example 1 of the present invention;

[0042] Figure 5 This is a structural diagram of a third control module in a second auxiliary power supply module in a DCDC bidirectional charge and discharge device provided in Example 1 of the present invention;

[0043] Figure 6 This is a circuit diagram of a DCDC bidirectional charging and discharging device provided in Example 1 of the present invention;

[0044] In the figure: 101, first bidirectional inverter module; 102, first transformer; 103, second bidirectional inverter module; 104, first power module; 105, second power module; 106, first auxiliary power supply module; 107, second auxiliary power supply module; 108, first control module; 111, first rectifier and filter module; 112, second transformer; 113, second control module; 121, first enabling unit; 122, first control unit; 123, first power unit; 131, second rectifier and filter module; 132, third transformer; 133, third control module; 141, second enabling unit; 142, second control unit; 143, second power unit. DETAILED DESCRIPTION

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] Example 1

[0051] This embodiment provides a DCDC bidirectional charging and discharging device, such as Figure 1 As shown, including:

[0052] A first bidirectional inverter module 101, one end of which is connected to the first power module 104, and performs bidirectional conversion between a first DC voltage output or received by the first power module 104 and a first AC voltage;

[0053] A first transformer 102, comprising a primary coil and a secondary coil, wherein the primary coil is connected to the other end of the first bidirectional inverter module 101;

[0054] A second bidirectional inverter module 103, one end of which is connected to the secondary coil and the other end of which is connected to the second power module 105, performs bidirectional conversion between the second DC voltage output or received by the second power module 105 and the second AC voltage, wherein the first DC voltage is lower than the second DC voltage;

[0055] A first auxiliary power supply module 106 , one end of which is connected to the second power supply module 105 , and the other end of which is connected to the first power supply module 104 ;

[0056] A second auxiliary power supply module 107, one end of which is connected to the first power supply module 104 and the first auxiliary power supply module 106;

[0057] A first control module 108, which is respectively connected to the control end of the first bidirectional inverter module 101, the control end of the second bidirectional inverter module 103 and the other end of the second auxiliary power supply module 107;

[0058] The first power supply module 104 outputs a first DC voltage to the second auxiliary power supply module 107;

[0059] The first auxiliary power supply module 106 converts the second DC voltage according to the first control signal and outputs a third DC voltage to the second auxiliary power supply module 107;

[0060] The second auxiliary power supply module 107 converts the first DC voltage or the third DC voltage according to the second control signal and outputs the startup voltage to the first control module 108 .

[0061] The first bidirectional inverter module 101 performs bidirectional AC / DC voltage conversion between the first power module 104 and the first transformer 102, supporting bidirectional energy flow. The first bidirectional inverter module 101 can adopt a full-bridge or half-bridge inverter topology, for example, a bridge inverter circuit consisting of four MOSFETs / IGBTs, which can operate in forward or reverse directions using PWM control. The first transformer 102 provides electrical isolation and converts energy between the first and second sides. The first transformer 102 can be a high-frequency isolation transformer with primary and secondary windings and an E-shaped or toroidal core. The second bidirectional inverter module 103 performs bidirectional AC / DC conversion between the second power module 105 and the secondary side of the first transformer 102, supporting charging or discharging operations. The second bidirectional inverter module 103 can also adopt a full-bridge or half-bridge topology, supporting conversion from high-voltage DC to AC or vice versa. The first auxiliary power supply module 106 draws power from the second power module 105 (high-voltage side), steps down and isolates it, and then outputs it to the first power module 104 (low-voltage side) for auxiliary power supply. The first auxiliary power supply module 106 can be a low-power isolated DC-DC converter, such as a flyback or forward topology, with a rectifier output and a voltage stabilization module. The second auxiliary power supply module 107 receives the first DC voltage output by the first power supply module 104, or receives the third DC voltage output by the first auxiliary power supply module 106, processes it, and outputs a stable startup voltage to the first control module 108. The second auxiliary power supply module 107 can be an auxiliary DC-DC module with multiple input terminals, internally including a switching power supply chip, an inductor, a capacitor, a rectifier, and input selection logic. The first control module 108 is used to centrally control the entire machine, control the conduction and conversion of the first bidirectional inverter module 101 and the second bidirectional inverter module 103, and receive the startup voltage of the second auxiliary power supply module 107. The first control module 108 can be based on an MCU or DSP, and is composed of a driver chip, an AD sampling circuit, a communication interface, etc.

[0062] The working process of this technical solution is as follows:

[0063] 1. Startup of the first power module 104 (low-voltage side): The first power module 104 outputs a first DC voltage, which is supplied to the second auxiliary power supply module 107. The second auxiliary power supply module 107 converts the first DC voltage and outputs a startup voltage to the first control module 108. The first control module 108 detects a valid voltage and starts the first bidirectional inverter module 101. The first bidirectional inverter module 101 outputs an AC signal to the primary side of the first transformer 102. This AC signal is transmitted to the secondary side of the first transformer 102, where it is converted into a second DC voltage by the second bidirectional inverter module 103 for charging the second power module 105 (implementing boost charging).

[0064] 2. Startup of the second power supply module 105 (high-voltage side): The first auxiliary power supply module 106 connects to the second power supply module 105 to obtain the second DC voltage; after conversion, it outputs a third DC voltage to the second auxiliary power supply module 107; the second auxiliary power supply module 107 converts the third DC voltage and outputs a startup voltage to the first control module 108; the first control module 108 starts the system and drives the second bidirectional inverter module 103 to invert the second DC voltage into an AC signal; the AC signal is transmitted to the primary coil through the first transformer 102, rectified by the first bidirectional inverter module 101 into the first DC voltage, and output to the first power supply module 104 (to achieve step-down discharge).

[0065] The technical effect of the technical solution provided in the first embodiment is that: by providing a two-stage auxiliary power supply module, the system can be autonomously started when there is voltage in the battery on either side, thereby solving the problem that the existing isolated bidirectional DCDC converter cannot start when fed by a low-voltage battery or in a dormant state; the first auxiliary power supply module 106 uses the high-voltage side power energy to supply power to the second auxiliary power supply module 107, and the second auxiliary power supply module 107 is combined to convert the voltage from either side to output the startup voltage, thereby ensuring that the first control module 108 has a stable power-on capability, realizing bidirectional self-activation startup of the system, improving the reliability and practicality of the system, and effectively meeting the application requirements of multiple scenarios such as on-board charging.

[0066] As an implementation manner, the second auxiliary power supply module 107 converts the larger one of the first DC voltage and the third DC voltage according to the second external control signal and outputs the startup voltage to the first control module 108 .

[0067] The second auxiliary power supply module 107 includes a multi-input power supply selection circuit having two input terminals, each receiving a first DC voltage from the first power supply module 104 and a third DC voltage from the first auxiliary power supply module 106. A voltage comparison and switching unit is internally provided within the second auxiliary power supply module 107, which is configured to detect the voltage levels of the two inputs in real time upon receiving a second external control signal and select the one with the higher voltage as the primary power supply. The selected power supply undergoes power conversion processing via a boost, rectifier, or voltage regulator module, and then outputs a stable startup voltage to the first control module 108. The second external control signal can be issued by the system control unit based on the current operating mode, input power status, or user-configured policy to trigger the input voltage comparison and selection process.

[0068] The technical effect of this embodiment is that by introducing a dual-input comparison and selection mechanism in the second auxiliary power supply module 107, it can automatically select the higher voltage of the first DC voltage and the third DC voltage for conversion and output after receiving the second control signal, thereby providing a more stable and reliable starting voltage for the first control module 108; this solution not only improves the system's adaptability under different power supply conditions, but also avoids the control failure problem caused by insufficient low-voltage power supply, significantly enhancing the startup reliability and operation safety of the entire machine.

[0069] As an implementation method, Figure 2 As shown, the first auxiliary power supply module 106 includes a second transformer 112, a first rectifier and filter module 111, and a second control module 113. The first end of the primary coil of the second transformer 112 is connected to the positive pole of the second power module 105, the second end of the primary coil of the second transformer 112 is connected to one end of the second control module 113, and the other end of the second control module 113 is connected to the negative pole of the second power module 105. The first end of the secondary coil of the second transformer 112 is connected to the first input end of the first rectifier and filter module 111, the second end of the secondary coil of the second transformer 112 is connected to the second input end of the first rectifier and filter module 111, the first output end of the first rectifier and filter module 111 is connected to the positive pole of the first power module 104, and the second output end of the first rectifier and filter module 111 is connected to the negative pole of the first power module 104; the second control module 113 controls the second transformer 112 to convert the second DC voltage into the second AC voltage according to the first control signal; the first rectifier and filter module 111 rectifies and filters the second AC voltage and outputs a third DC voltage.

[0070] The second transformer 112 is used to achieve electrical isolation and voltage conversion between the second power module 105 (high-voltage side) and the second auxiliary power supply module 107. The second transformer 112 can be an isolated high-frequency transformer. Its primary coil is connected to the second power module 105, and its secondary coil outputs an AC voltage for rectification and filtering by the first rectifier and filter module 111. The second control module 113 receives a first control signal and performs switching control on the DC voltage provided by the second power module 105, converting it into a high-frequency AC voltage and inputting it into the second transformer 112. The second control module 113 may include a DC-DC controller consisting of a PWM control driver and power switching devices (such as MOSFETs or IGBTs), for example, using a forward or flyback topology. The first rectifier and filter module 111 is used to rectify and filter the AC power output by the second transformer 112, ultimately outputting a stable third DC voltage for the second auxiliary power supply module 107. The first rectifier and filter module 111 may include a rectifier bridge (diodes or synchronous rectifiers) and filter capacitors.

[0071] The technical effect of this embodiment is that by providing a second transformer 112, a second control module 113, and a first rectifier and filter module 111 in the first auxiliary power supply module 106, when the second power supply module 105 has power output, its high-voltage DC power is converted into isolated, stable low-voltage DC power, and output to the first power supply module 104 or the second auxiliary power supply module 107. This ensures that the high-voltage side can still actively provide the startup voltage when the system is fed by the low-voltage side battery. This solution significantly improves the system's self-recovery capability and overall power supply redundancy under abnormal operating conditions, effectively enhancing the safety and reliability of the bidirectional DC-DC system.

[0072] As an implementation method, Figure 3 As shown, the second control module 113 includes:

[0073] A first enabling unit 121, configured to receive a first control signal and output a first enabling signal;

[0074] A first control unit 122, whose input end is connected to the output end of the first enabling unit 121, outputs a first PWM control signal according to a first enabling signal;

[0075] The first power unit 123 has a control end connected to the output end of the first control unit 122, a first output end of the first power unit 123 is one end of the second control module 113, and a second output end of the first power unit 123 is the other end of the second control module 113, and is used to convert the second DC voltage into a third AC voltage according to the first PWM control signal.

[0076] Among them, the first enabling unit 121 is used to receive the first control signal output by the first control module 108 and output the first enabling signal when the enabling condition is met. The first enabling unit 121 can be a level recognition circuit, an optocoupler isolator, or a simple MOS switch circuit, which is used to ensure that the subsequent circuit starts working only under permitted conditions. The first control unit 122 has an input end connected to the output end of the first enabling unit 121; when receiving the first enabling signal, the first control unit 122 starts working and outputs a first PWM control signal. The first control unit 122 can be an independent PWM control chip or a PWM logic module integrated in the MCU, which is used to control the frequency and duty cycle of the PWM. The first power unit 123 has a control end connected to the output end of the first control unit 122 and is used to receive the first PWM control signal. One end of the first power unit 123 is connected to the positive pole of the second power module 105, and the other end is connected to the negative pole of the second power module 105, forming a chopping path. Driven by the first PWM control signal, the first power unit 123 converts the high-voltage DC voltage of the second power module 105 into a high-frequency third AC voltage for subsequent input to the primary coil of the transformer.

[0077] The technical effect of this embodiment is that: by introducing a hierarchical control structure of the first enabling unit 121, the first control unit 122 and the first power unit 123 in the second control module 113, precise management and conversion of the output voltage of the second power supply module 105 is achieved; after receiving the first control signal, this embodiment can intelligently drive the power unit to convert high-voltage direct current into high-frequency alternating current, providing input for subsequent isolation transformation, effectively improving the system's response speed and control accuracy, while enhancing the module's startup flexibility and the safety and reliability of the overall system.

[0078] As an embodiment, the first rectifier and filter module 111 includes a first diode, a second diode and a first capacitor, the anode of the first diode is the first input terminal of the first rectifier and filter module 111, the cathode of the first diode is respectively connected to the anode of the second diode and one end of the first capacitor, the cathode of the second diode is the first output terminal of the first rectifier and filter module 111, and the other end of the first capacitor is respectively the second input terminal and the second output terminal of the first rectifier and filter module 111.

[0079] The first diode, as a rectifier, is used to conduct and transmit current during the positive half-cycle of the AC power input from the secondary coil of the second transformer 112, providing a rectification channel for the subsequent stage. The second diode and the first diode together form a half-bridge rectifier structure, which conducts during the negative half-cycle of the secondary output of the second transformer 112 to achieve full-wave rectification of the AC power. The first capacitor is used to filter the pulsating DC voltage after rectification, eliminate the AC component in the voltage, and output a stable DC voltage.

[0080] The technical effect of this embodiment is that by arranging the first diode, the second diode and the first capacitor in the first rectifier and filter module 111, effective rectification and filtering of the high-frequency alternating current outputted by the transformer secondary is achieved, and a stable third DC voltage is outputted; the structure is simple and responsive, and can significantly reduce the ripple of the output voltage, thereby improving the stability and reliability of the auxiliary power supply, thereby providing a safer and more continuous power supply guarantee for the subsequent control module.

[0081] As an implementation method, Figure 4As shown, the second auxiliary power supply module 107 includes a third transformer 132, a second rectifier and filter module 131, and a third control module 133. The first end of the primary coil of the third transformer 132 is connected to the positive electrode of the first power module 104, the second end of the primary coil of the third transformer 132 is connected to one end of the third control module 133, and the other end of the third control module 133 is connected to the negative electrode of the first power module 104. The first end of the secondary coil of the third transformer 132 is connected to the first input end of the second rectifier and filter module 131, the second end of the secondary coil of the third transformer 132 is connected to the second input end of the second rectifier and filter module 131, the first output end of the second rectifier and filter module 131 is connected to the first power input end of the first control module 108, and the second output end of the second rectifier and filter module 131 is connected to the second power input end of the first control module 108;

[0082] The third control module 133 controls the third transformer 132 to convert the third DC voltage into a fourth AC voltage according to the second control signal;

[0083] The second rectifying and filtering module 131 rectifies and filters the fourth AC voltage and then outputs a startup voltage.

[0084] The third transformer 132 achieves electrical isolation and is used to convert the DC power provided by the first power module 104 and transmit it to the second rectifier and filter module 131. The third transformer 132 can be a high-frequency isolation transformer. Its primary coil receives high-frequency AC power after switching, and its secondary output voltage is rectified and filtered before output. The core can be an E-shaped or ring-shaped structure to reduce leakage inductance. After receiving the second control signal, the third control module 133 drives the third DC voltage provided by the first power module 104 to convert it into high-frequency pulses (a fourth AC voltage) for input to the third transformer 132. The third control module 133 can include a PWM control unit and a power switch unit. The PWM control unit generates a PWM signal with a specific frequency and duty cycle. The power switch unit can include a MOSFET or IGBT for chopping DC power into AC power. The second rectifier and filter module 131 rectifies and filters the fourth AC voltage output from the secondary of the third transformer 132 to form a stable startup voltage. The second rectifier and filter module 131 can be structured to include a rectifier bridge (diodes or synchronous rectifiers) and a filter capacitor.

[0085] The operating process of this embodiment is as follows: upon receiving the second control signal, the third control module 133 activates and outputs a PWM signal to control the on / off switching of the power devices, converting the third DC voltage into a high-frequency pulsating voltage (i.e., the fourth AC voltage) and supplying it to the primary coil of the third transformer 132. The third transformer 132 converts this voltage to a secondary coil, which is then output to the second rectifier and filter module 131. The second rectifier and filter module 131 rectifies and filters the voltage, ultimately outputting a stable startup voltage, which is then supplied to the first and second power inputs of the first control module 108, respectively, ensuring a stable operating voltage for the system control core.

[0086] The technical effect of this embodiment is that by providing the third transformer 132, the third control module 133, and the second rectifier and filter module 131 in the second auxiliary power supply module 107, it is possible to autonomously convert the DC voltage of the first power supply module 104 into isolated high-frequency AC power when the first power supply module 104 has output capability, and further rectify and filter the output to provide a stable startup voltage for the control module. This design not only improves the independence and reliability of the system during low-voltage startup, but also enhances the system's safety and anti-interference capabilities through the isolation structure, providing a flexible and efficient auxiliary startup solution for bidirectional power supply systems.

[0087] As an implementation method, Figure 5 As shown, the third control module 133 includes:

[0088] A second enabling unit 141, configured to receive a second control signal and output a second enabling signal;

[0089] A second control unit 142, whose input terminal is connected to the output terminal of the second enabling unit 141, outputs a second PWM control signal according to the second enabling signal;

[0090] The second power unit 143, whose control end is connected to the output end of the second control unit 142, whose first output end is one end of the third control module 133, and whose second output end is the other end of the third control module 133, is used to convert the third DC voltage into the fifth AC voltage according to the second PWM control signal.

[0091] The second enabling unit 141 receives a second control signal from the system controller, determines whether to enter the operating state, and outputs a second enabling signal when conditions are met, which activates the subsequent control and power units. This second enabling unit 141 can utilize an optocoupler (for isolation and interference rejection), a level detection circuit, a MOS switch, or a level converter to perform logic judgment and drive signal isolation. Upon receiving the second enabling signal from the second enabling unit 141, the second control unit 142 activates and generates a second PWM control signal with a specific frequency and duty cycle to drive the second power unit 143. This second control unit 142 utilizes a dedicated PWM controller or is implemented within a microcontroller (MCU)'s internal PWM timer module. The output frequency typically ranges from tens to hundreds of kHz, making it suitable for driving power devices such as MOSFETs. The second power unit 143 is turned on and off according to the second PWM second signal output by the second control unit 142, thereby chopping the third DC voltage and outputting a high-frequency pulse AC signal (i.e., the fifth AC voltage) for stimulating the third transformer 132; the second power unit 143 can adopt a single-tube switch mode, or a push-pull, half-bridge, full-bridge or other structures, and power devices such as N-type MOSFET or IGBT.

[0092] The technical effect of this embodiment is that by setting a second enabling unit 141, a second control unit 142 and a second power unit 143 in the third control module 133, controlled high-frequency conversion of the third DC voltage is achieved, and a stable fifth AC voltage is output for use by the transformer; this embodiment not only improves the flexibility and reliability of low-voltage side power supply startup, but also realizes precise triggering and energy management of system startup through hierarchical control, effectively improving the adaptability and safety performance of the overall system under various working conditions.

[0093] As an embodiment, the second rectifier and filter module 131 includes a third diode and a second capacitor, the anode of the third diode is the first input terminal of the second rectifier and filter module 131, the cathode of the third diode and one end of the second capacitor are connected together as the first output terminal of the second rectifier and filter module 131, and the other end of the second capacitor is the second input terminal and the second output terminal of the second rectifier and filter module 131 respectively.

[0094] Among them, the third diode is used to rectify the fifth AC voltage output by the third control module 133 after conversion by the transformer, and conduct it unidirectionally into pulsating DC power; the second capacitor is used to filter and smooth the pulsating DC voltage after rectification by the third diode to eliminate voltage ripple and output a stable DC starting voltage.

[0095] The technical effect of this embodiment is that by providing a third diode and a second capacitor in the second rectifier-filter module 131, efficient rectification and filtering of the high-frequency fifth AC voltage is achieved, outputting a stable, low-ripple DC startup voltage and providing a reliable operating power supply for the control module. This structure offers fast response and a compact size, ensuring voltage conversion efficiency while improving system stability and overall power supply quality during low-voltage startup.

[0096] The present embodiment is described below through a specific circuit structure: Figure 6 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 form a first terminal of the first bidirectional inverter module 101 and connected to the positive electrode of the first power module 104. 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 and connected to the negative electrode of the first power module 104. 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 and connected to the first terminal of the primary coil of the transformer TX1. 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 and connected to the second terminal of the primary coil of the transformer TX1.

[0097] The second bidirectional inverter module 103 includes a fifth MOS transistor Q5, a sixth MOS transistor Q6, a seventh MOS transistor Q7, and an eighth MOS transistor Q8. The source of the fifth MOS transistor Q5 and the drain of the seventh MOS transistor Q7 are connected together to form a first terminal of the second bidirectional inverter module 103 and connected to the first end of the secondary winding of the transformer TX1. The source of the sixth MOS transistor Q6 and the drain of the eighth MOS transistor Q8 are connected together to form a second terminal of the second bidirectional inverter module 103 and connected to one end of the inductor L1. The other end of the inductor L1 is connected to one end of the capacitor C5. The other end of the capacitor C5 is connected to the second end of the secondary winding of the transformer TX1. The drain of the fifth MOS transistor Q5 and the drain of the sixth MOS transistor Q6 are connected together to form a third terminal of the second bidirectional inverter module 103 and connected to the positive electrode of the second power module 105. The source of the seventh MOS transistor Q7 and the source of the eighth MOS transistor Q8 are connected together to form a fourth terminal of the second bidirectional inverter module 103 and connected to the negative electrode of the second power module 105.

[0098] The first auxiliary power supply module 106 includes a transformer T1, a diode D1, a diode D2, a capacitor C1 and a second control module 113. The first end of the primary coil of the transformer T1 is connected to the positive electrode of the second power module 105, the first end of the primary coil of the transformer T1 is connected to the first end of the second control module 113, the second end of the second control module 113 is connected to the negative electrode of the second power module 105, the first end of the secondary coil of the transformer T1 is connected to the anode of the diode D1, the cathode of the diode D1 is respectively connected to the anode of the diode D2 and the first end of the capacitor C1, the cathode of the diode D2 is connected to the cathode of the diode D6, the anode of the diode D6 is connected to the positive electrode of the first power module 104, and the second end of the secondary coil of the transformer T1 is respectively connected to the second end of the capacitor C1 and the negative electrode of the first power module 104.

[0099] The second auxiliary power supply module 107 includes a transformer T2, a diode D3, a diode D4, a diode D5, a capacitor C2, a capacitor C3, a capacitor C4, and a third control module 133. A first end of the primary coil of the transformer T2 is connected to the cathode of the diode D6, a second end of the primary coil of the transformer T2 is connected to the first end of the third control module 133, and a second end of the third control module 133 is connected to the negative electrode of the first power supply module 104. A first end of the secondary coil of the transformer T2 is connected to the anode of the diode D3, and the cathode of the diode D3 and the first end of the capacitor C2 are connected together to form a first output end. A second end of the secondary coil of the transformer T2 is connected to the anode of the diode D4, and the cathode of the diode D4 and the first end of the capacitor C3 are connected together to form a second output end. A third end of the secondary coil of the transformer T2, the second end of the capacitor C3, and the first end of the capacitor C4 are connected together to form a negative output end. A fourth end of the secondary coil of the transformer T2 is connected to the cathode of the diode D5, and the anode of the diode D5 and the second end of the capacitor C4 are connected together to form a third output end.

[0100] The working process of this circuit structure is as follows: the first power supply module 104 provides energy input for the first power conversion unit and also provides power supply for the second auxiliary power supply module 107. After conversion, the second auxiliary power supply module 107 outputs the power from the secondary side second rectifier filter unit (diode D3 and capacitor C2) and the third rectifier filter unit (diode D4 and capacitor C3) to provide auxiliary power supply for the first control module 108. The fourth rectifier filter unit (diode D5 and capacitor C4) is used to input power. The fourth rectifier filter unit is connected to an external power supply. When the power of the first power supply module 104 and the second power supply module 105 is low, The system is used to power the first power module 104 or the second power module 105. The energy isolated and converted by the main transformer TX1 is output via the second power module 105 (i.e., the high-voltage side), providing power to the first auxiliary power supply module 106. The energy input to the first auxiliary power supply module 106 is converted and output via the secondary-side first rectifier and filter module to provide power to the second auxiliary power supply module 107. The energy is then converted by the second auxiliary power supply module 107 and output via the secondary-side second, third, and fourth rectifier and filter units to provide auxiliary power to the first control module 108. The energy for the second auxiliary power supply module 107 is supplied both from the low-voltage input and from the output of the first auxiliary power supply module 106. The energy for the first auxiliary power supply module 106 is supplied from the high-voltage side. This means that the auxiliary power supply system can provide stable and reliable power to the entire device, regardless of whether it is input from the low-voltage side or the high-voltage side. The system can also remotely control the auxiliary power supply by receiving external communication, completing bidirectional startup control of the entire bidirectional power converter.

[0101] Example 2

[0102] The second embodiment provides a DCDC bidirectional charge and discharge system, including the DCDC bidirectional charge and discharge device provided in the first embodiment, a first power module, and a second power module.

[0103] 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 device, characterized in that: include: a first bidirectional inverter module, one end of which is connected to the first power module and performs bidirectional conversion between a first DC voltage output or received by the first power module and a first AC voltage; a first transformer comprising a primary coil and a secondary coil, wherein the primary coil is connected to the other end of the first bidirectional inverter module; a second bidirectional inverter module, one end of which is connected to the secondary coil and the other end of which is connected to the second power supply module, and bidirectionally converts a second DC voltage output or received by the second power supply module into a second AC voltage, wherein the first DC voltage is lower than the second DC voltage; a first auxiliary power supply module, one end of which is connected to the second power supply module and the other end of which is connected to the first power supply module; a second auxiliary power supply module, one end of which is connected to the first power supply module and the first auxiliary power supply module respectively; a first control module, which is respectively connected to the control end of the first bidirectional inverter module, the control end of the second bidirectional inverter module, and the other end of the second auxiliary power supply module; The first power supply module outputs a first DC voltage to the second auxiliary power supply module; The first auxiliary power supply module converts the second DC voltage according to the first control signal and outputs a third DC voltage to the second auxiliary power supply module; The second auxiliary power supply module converts the first DC voltage or the third DC voltage according to the second control signal and outputs a starting voltage to the first control module; The second auxiliary power supply module converts the larger of the first DC voltage and the third DC voltage according to a second external control signal and outputs a starting voltage to the first control module; The second auxiliary power supply module includes a multi-input power supply selection circuit having two input terminals, each receiving a first DC voltage from the first power supply module and a third DC voltage from the first auxiliary power supply module; the second auxiliary power supply module is internally provided with a voltage comparison and switching unit for detecting the level values ​​of the two input voltages in real time after receiving a second external control signal, and selecting the one with the larger voltage value as the main power supply; The second auxiliary power supply module includes a third transformer, a second rectifier and filter module, and a third control module. The first end of the primary coil of the third transformer is connected to the positive electrode of the first power module, the second end of the primary coil of the third transformer is connected to one end of the third control module, and the other end of the third control module is connected to the negative electrode of the first power module. The first end of the secondary coil of the third transformer is connected to the first input end of the second rectifier and filter module, the second end of the secondary coil of the third transformer is connected to the second input end of the second rectifier and filter module, the first output end of the second rectifier and filter module is connected to the first power input end of the first control module, and the second output end of the second rectifier and filter module is connected to the second power input end of the first control module. The third control module controls the third transformer to convert the third DC voltage into a fourth AC voltage according to the second control signal; The second rectifying and filtering module rectifies and filters the fourth AC voltage and then outputs a startup voltage; The third control module includes: A second enabling unit, configured to receive a second control signal and output a second enabling signal; a second control unit, an input end of which is connected to the output end of the second enabling unit, and outputs a second PWM control signal according to the second enabling signal; A second power unit, whose control end is connected to the output end of the second control unit, whose first output end is one end of the third control module, and whose second output end is the other end of the third control module, is used to convert the larger of the first DC voltage and the third DC voltage into a fifth AC voltage according to the second PWM control signal.

2. The DCDC bidirectional charge and discharge device according to claim 1, wherein: The first auxiliary power supply module includes a second transformer, a first rectifier and filter module, and a second control module. The first end of the primary coil of the second transformer is connected to the positive pole of the second power module, the second end of the primary coil of the second transformer is connected to one end of the second control module, and the other end of the second control module is connected to the negative pole of the second power module. The first end of the secondary coil of the second transformer is connected to the first input end of the first rectifier and filter module, the second end of the secondary coil of the second transformer is connected to the second input end of the first rectifier and filter module, the first output end of the first rectifier and filter module is connected to the positive pole of the first power module, and the second output end of the first rectifier and filter module is connected to the negative pole of the first power module. The second control module controls the second transformer to convert the second DC voltage into a second AC voltage according to the first control signal; The first rectifying and filtering module rectifies and filters the second alternating current voltage and outputs a third direct current voltage.

3. The DCDC bidirectional charge and discharge device according to claim 2, wherein: The second control module includes: A first enabling unit, configured to receive a first control signal and output a first enabling signal; a first control unit, an input end of which is connected to the output end of the first enabling unit, and outputs a first PWM control signal according to the first enabling signal; A first power unit, whose control end is connected to the output end of the first control unit, whose first output end is one end of the second control module, and whose second output end is the other end of the second control module, is used to convert the second DC voltage into a third AC voltage according to the first PWM control signal.

4. The DCDC bidirectional charge and discharge device according to claim 2, wherein: The first rectifier and filter module includes a first diode, a second diode and a first capacitor, the anode of the first diode is the first input end of the first rectifier and filter module, the cathode of the first diode is respectively connected to the anode of the second diode and one end of the first capacitor, the cathode of the second diode is the first output end of the first rectifier and filter module, and the other end of the first capacitor is respectively the second input end and the second output end of the first rectifier and filter module.

5. The DCDC bidirectional charge and discharge device according to claim 1, wherein: The second rectifier and filter module includes a third diode and a second capacitor, the anode of the third diode is the first input end of the second rectifier and filter module, the cathode of the third diode and one end of the second capacitor are connected together as the first output end of the second rectifier and filter module, and the other end of the second capacitor is the second input end and the second output end of the second rectifier and filter module respectively.

6. The DCDC bidirectional charge and discharge device according to claim 1, wherein: The DCDC bidirectional charge and discharge device further includes a sixth diode, an anode of the sixth diode is connected to the positive electrode of the first power module, and a cathode of the sixth diode is connected to the first end of the primary coil of the third transformer.

7. A DCDC bidirectional charging and discharging system, characterized in that: The device comprises the DCDC bidirectional charge and discharge device according to any one of claims 1 to 6, a first power module and a second power module.

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