A bidirectional conversion circuit, energy transmission control method and device

Abstract

The application provides a bidirectional conversion circuit, an energy transmission control method and device, and relates to the technical field of automobiles.The bidirectional conversion circuit comprises at least two DC-DC main conversion circuits;each DC-DC main conversion circuit comprises a transformer, a first conversion circuit and a second conversion circuit;the first end of the first conversion circuit is connected to the first connecting end of the transformer, and the first end of at least two second conversion circuits is connected to the second connecting end of the transformer;the first conversion circuit of each DC-DC main conversion circuit is connected to a high-voltage power battery, and the second conversion circuit of each DC-DC main conversion circuit is connected to an external connecting end;the external connecting end is connected to an external power supply or a load.The topological structure of the scheme is simple, energy transmission can be realized in bidirectional operation, and the efficiency of external power supply is improved through the at least two DC-DC main conversion circuits.

Description

Technical Field

[0001] This application relates to the field of automotive technology, and in particular to a bidirectional conversion circuit, an energy transmission control method, and a device. Background Technology

[0002] Pure electric vehicles and range-extended electric vehicles both include a high-to-low voltage conversion module (DC-DC converter to DC / DC converter) to convert the high-voltage electricity from the power battery or hydrogen fuel cell energy storage unit into low-voltage electricity to power the battery and the vehicle's low-voltage electrical components. With the application of in-vehicle entertainment and autonomous driving technologies, the peak power of DC / DC converters has gradually increased from 1-2kW to 3-4kW, while simultaneously placing higher demands on their reliability. However, in practical applications, although the peak power is relatively high, the power used under most operating conditions is not high, typically between 500W and 1kW. For DC / DC converter product design, half-load conditions yield the highest efficiency. Therefore, if a DC / DC converter product is designed for a 3-4kW requirement, its high-efficiency range is 1.5-2kW, which does not match common operating conditions. Summary of the Invention

[0003] This application provides a bidirectional conversion circuit, an energy transfer control method, and an apparatus to solve the problem of low efficiency in existing DC / DC converters.

[0004] To solve the above-mentioned technical problems, this application adopts the following technical solution:

[0005] This application provides a bidirectional conversion circuit, including:

[0006] At least two DC / DC-DC main converter circuits;

[0007] Each of the aforementioned DC-DC main converter circuits includes:

[0008] A transformer, a first conversion circuit, and a second conversion circuit; wherein, a first terminal of the first conversion circuit is connected to a first connection terminal of the transformer, and at least two first terminals of the second conversion circuits are connected to a second connection terminal of the transformer;

[0009] In each of the DC-DC main converter circuits, the first converter circuit is connected to a high-voltage power battery, and the second converter circuit is connected to an external terminal; the external terminal is connected to an external power source or load.

[0010] Optionally, when the external terminal is connected to a load, wherein,

[0011] The second terminal of the first converter circuit of the DC-DC main converter circuit is connected to the high-voltage power battery and the second terminal of the first converter circuit of another DC-DC main converter circuit.

[0012] The second terminal of the second converter circuit of the DC-DC main converter circuit is connected to the load and the second terminal of the second converter circuit of another DC-DC main converter circuit.

[0013] Optionally, when the external terminal is connected to an external power supply, the second conversion circuit of the DC-DC main converter circuit includes:

[0014] First winding control circuit and first resonant circuit;

[0015] The first resonant circuit is connected to the first winding control circuit and the external power supply, respectively.

[0016] The first winding control circuit is also connected to the second connection terminal of the transformer of the DC-DC main converter circuit;

[0017] The second conversion circuit of the other DC-DC main conversion circuit includes:

[0018] Second winding control circuit;

[0019] The second winding control circuit is connected to the second connection terminal of the transformer of the other DC-DC main converter circuit and the first winding control circuit, respectively.

[0020] Optionally, the bidirectional conversion circuit further includes:

[0021] A controller and a detection circuit connected to the controller;

[0022] The detection circuit is also connected to the first and second conversion circuits of each of the DC-DC main conversion circuits.

[0023] The controller receives the detection signal from each DC-DC main converter circuit detected by the detection circuit, and uses it to determine the fault condition of each DC-DC main converter circuit and control the power switch of each DC-DC main converter circuit to turn on and off.

[0024] This application embodiment also provides an energy transfer control method applied to the bidirectional conversion circuit as described in any of the preceding claims, the method comprising:

[0025] Obtain the required output power and the output power of the bidirectional conversion circuit;

[0026] The on / off state of each DC-DC main converter circuit is determined based on the required output power and the output power.

[0027] Optionally, determining the on / off state of each DC-DC main converter circuit based on the required output power and the outputtable power includes:

[0028] By comparing the required output power with the output power available, a circuit combination of DC-DC main converter circuits that can meet the required output power is determined.

[0029] Based on the circuit combination, determine the on / off state of each DC-DC main converter circuit.

[0030] Optionally, when the bidirectional conversion circuit includes a controller and a detection circuit connected to the controller; and the detection circuit is further connected to a first conversion circuit and a second conversion circuit of each of the DC-DC main conversion circuits, the method further includes:

[0031] The detection signal detected by the detection circuit for each of the DC-DC main converter circuits is obtained;

[0032] Based on the detected signal, determine the fault condition of the corresponding DC-DC main converter circuit;

[0033] If the fault condition of the corresponding DC-DC main converter circuit is a faulty circuit, then the power switch of the corresponding DC-DC main converter circuit is disconnected; otherwise, the power switch of the corresponding DC-DC main converter circuit is closed.

[0034] Optionally, the method further includes:

[0035] Obtain the power transmission direction of the DC-DC main converter circuit, and the connection status of the external terminals of the second converter circuit of the DC-DC main converter circuit;

[0036] The on / off state of each DC-DC main converter circuit is determined based on the connection status of the external terminals and the power transmission direction.

[0037] Optionally, when the external terminals of the second conversion circuit are connected to an external power supply and a load,

[0038] The step of determining the on / off state of each DC-DC main converter circuit based on the connection status of the external terminal and the power transmission direction includes:

[0039] When the power transmission direction of the bidirectional conversion circuit is from the second conversion circuit connected to the external power supply to the second conversion circuit connected to the load, the first conversion circuit of each DC-DC main conversion circuit is controlled to be in an open state, and the second conversion circuit connected to the external power supply and the second conversion circuit connected to the load are in a closed state.

[0040] When the power transmission direction of the bidirectional conversion circuit is from the first conversion circuit connected to the high-voltage power battery to the second conversion circuit connected to the load, the second conversion circuit connected to the external power source in each DC-DC main conversion circuit is controlled to be in an open state, while the first conversion circuit and the second conversion circuit connected to the load are in a closed state.

[0041] When the power transmission direction of the bidirectional conversion circuit is from the first conversion circuit to the second conversion circuit connected to the external power supply, the second conversion circuit connected to the load of each DC-DC main conversion circuit is controlled to be in an open state, while the first conversion circuit and the second conversion circuit connected to the external power supply are in a closed state.

[0042] This application embodiment also provides an energy transmission control device applied to the bidirectional conversion circuit as described in any of the preceding claims, the device comprising:

[0043] The acquisition module is used to acquire the required output power and the output power of the bidirectional conversion circuit.

[0044] The determination module is used to determine the on / off state of each DC-DC main converter circuit based on the required output power and the output power.

[0045] The beneficial effects of this application are:

[0046] In the above scheme, at least two DC / DC-DC main conversion circuits are set up; each DC-DC main conversion circuit includes: a transformer, a first conversion circuit, and a second conversion circuit; the first conversion circuit of each DC-DC main conversion circuit is connected to a high-voltage power battery, and the second conversion circuit of each DC-DC main conversion circuit is connected to an external terminal; the external terminal is connected to an external power supply or load. The circuit scheme of this application can obtain the required output power and the output power of the bidirectional conversion circuit; based on the required output power and the output power, the on / off state of each DC-DC main conversion circuit is determined, avoiding the problem of low efficiency in existing DC / DC converters. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of one of the bidirectional conversion circuits provided in the embodiments of this application;

[0048] Figure 2 This is a second schematic diagram of the bidirectional conversion circuit provided in the embodiments of this application;

[0049] Figure 3 This is a flowchart illustrating the energy transfer control method provided in an embodiment of this application;

[0050] Figure 4 This is a schematic diagram of the module of the energy transmission control device provided in the embodiments of this application. Detailed Implementation

[0051] To make the technical problems, technical solutions, and advantages of this application clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments. In the following description, specific details such as particular configurations and components are provided merely to aid in a comprehensive understanding of the embodiments of this application. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Furthermore, for clarity and brevity, descriptions of known functions and structures have been omitted.

[0052] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0053] In the various embodiments of this application, it should be understood that the sequence number of each process described below does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0054] This application addresses the problem of low efficiency in existing DC / DC converters by providing a bidirectional conversion circuit, an energy transfer control method, and an apparatus.

[0055] like Figure 1 As shown, an optional embodiment of this application provides a bidirectional conversion circuit, including:

[0056] At least two DC / DC-DC main converter circuits;

[0057] Each of the aforementioned DC-DC main converter circuits includes:

[0058] Transformer 1, first conversion circuit 2, and second conversion circuit 3; wherein, the first end of the first conversion circuit 2 is connected to the first connection end of the transformer 1, and the first ends of at least two of the second conversion circuits 3 are connected to the second connection end of the transformer 1;

[0059] In each of the DC-DC main converter circuits, the first converter circuit 2 is connected to the high-voltage power battery, and the second converter circuit 3 of each of the DC-DC main converter circuits is connected to an external terminal; the external terminal is connected to an external power source or load.

[0060] In this embodiment, the bidirectional conversion circuit employs at least two DC-DC main conversion circuits, and the at least two DC / DC-DC main conversion circuits are connected in parallel to prevent a failure of one DC-DC main conversion circuit from affecting the overall operation of the bidirectional conversion circuit. Each DC-DC main conversion circuit can be connected to a high-voltage power battery, and the second conversion circuit 3 of each DC-DC main conversion circuit is connected to an external terminal to realize energy transfer between the external power supply, the high-voltage power battery, and the load.

[0061] Optionally, the at least two DC / DC-DC main converter circuits may have the same circuit structure and / or circuit parameters, or the at least two DC / DC-DC main converter circuits may have different circuit structures and / or circuit parameters. The optimal number of the DC-DC converter circuits is 2 to 4.

[0062] Optionally, when the external terminal is connected to a load, the second terminal of the first conversion circuit 2 of the DC-DC main converter circuit is connected to the high-voltage power battery and the second terminal of the first conversion circuit 2 of another DC-DC main converter circuit.

[0063] The second terminal of the second conversion circuit 3 of the DC-DC main converter circuit is connected to the load and the second terminal of the second conversion circuit 3 of another DC-DC main converter circuit.

[0064] The external power source can be an external power grid such as 220V AC mains, or other electric vehicles. When the external power source is another electric vehicle, it can be connected via a bidirectional connector. The high-voltage power battery is the power battery used to provide energy to the electric vehicle (such as powering the drive motor); the load can be a low-voltage battery or low-voltage electrical equipment.

[0065] Optionally, when the external terminal is connected to an external power supply, the second conversion circuit 3 of the DC-DC main conversion circuit includes:

[0066] First winding control circuit and first resonant circuit 32;

[0067] The first resonant circuit 32 is connected to the first winding control circuit and the external power supply, respectively.

[0068] The first winding control circuit is also connected to the second connection terminal of the transformer 1 of the DC-DC main converter circuit;

[0069] The second conversion circuit of the other DC-DC main conversion circuit includes:

[0070] Second winding control circuit 31;

[0071] The second winding control circuit 31 is connected to the second connection terminal of the transformer 1 of the other DC-DC main converter circuit and the first winding control circuit, respectively.

[0072] The following is based on Figure 2 The circuit structure described above is explained in detail below. Specifically, the first conversion circuit includes: a first power switch Q1, a second power switch Q2, a third power switch Q3, and a fourth power switch Q4; wherein the first power switch Q1 and the fourth power switch Q4 constitute a first bridge arm; the second power switch Q2 and the third power switch Q3 constitute a second bridge arm; wherein one end of the first resonant circuit is connected to the connection terminal between the first power switch Q1 and the third power switch Q3, and the other end of the first resonant circuit is connected to the first connection terminal of the transformer 1; the first connection terminal of the transformer 1 is also connected to the connection terminal between the second power switch Q2 and the fourth power switch Q4. The first conversion circuit also includes: a first capacitor Cr2 and a first inductor Lr2.

[0073] The first resonant circuit 32 of the second conversion circuit connected to the external power supply includes: a fifth power switch Q5, a sixth power switch Q6, a seventh power switch Q7, and an eighth power switch Q8; wherein the fifth power switch Q5 and the eighth power switch Q8 constitute the third bridge arm; the sixth power switch Q6 and the seventh power switch Q7 constitute the fourth bridge arm; the second resonant circuit includes: a second capacitor Cr2 and a second inductor Lr2.

[0074] The second winding control circuit 31 of the second conversion circuit connected to the external power supply includes: a ninth power switch Q9 and a tenth power switch Q10; one end of the ninth power switch Q9 and one end of the tenth power switch Q10 are respectively connected to the second connection terminal of the transformer 1; the other end of the ninth power switch Q9 and the other end of the tenth power switch Q10 are respectively connected to the first resonant circuit 32; wherein, the first resonant circuit 32 is connected at the connection point between the two ends of the secondary winding of the transformer 1; when the ninth power switch is closed and the tenth power switch is open, the second conversion circuit and the ninth power switch form a first preset winding; when the ninth power switch is open and the tenth power switch is closed, the second conversion circuit and the tenth power switch form a second preset winding.

[0075] The second conversion circuit connected to the load includes: eleventh power switch Q11, twelfth power switch Q12, thirteenth power switch Q13, and fourteenth power switch Q14;

[0076] One end of the eleventh power switch Q11 and one end of the twelfth power switch Q12 are respectively connected to the two ends of the other secondary winding of the transformer 1; the other ends of the eleventh power switch Q11 and the twelfth power switch Q12 are respectively connected to the third conversion circuit. The thirteenth power switch Q13 is connected to the connection point between the two ends of the other secondary winding; the third inductor L4 is connected in series with the thirteenth power switch Q13; the fourteenth power switch Q14 is connected at one end to the third inductor L4 and at the other end to one end of the load; the third capacitor C3 and the first freewheeling diode D1 are connected in parallel with the two ends of the load.

[0077] Optionally, the bidirectional conversion circuit further includes:

[0078] A controller and a detection circuit connected to the controller;

[0079] The detection circuit is also connected to the first and second conversion circuits of each of the DC-DC main conversion circuits.

[0080] The controller receives the detection signal from each DC-DC main converter circuit detected by the detection circuit, and uses it to determine the fault condition of each DC-DC main converter circuit and control the power switch of each DC-DC main converter circuit to turn on and off.

[0081] In this embodiment, the advantages of the parallel scheme of the bidirectional conversion circuit of this application are mainly as follows: improved reliability, when one of the DC-DC main conversion circuits of the controller fails, the input and output of the faulty DC-DC main conversion circuit can be disconnected, and the normal DC-DC main conversion circuit continues to work; improved efficiency, according to the principle of optimal efficiency, only one DC-DC main conversion circuit works under light load, and at least two DC-DC main conversion circuits work under heavy load, which improves the efficiency under various working conditions.

[0082] In summary, the bidirectional conversion circuit of this application is provided with at least two DC-DC main conversion circuits. The on / off state of each DC-DC main conversion circuit can be determined according to the required output power, thereby improving the efficiency of the bidirectional conversion circuit and the reliability of external power supply.

[0083] like Figure 3 As shown, this application embodiment also provides an energy transfer control method applied to the bidirectional conversion circuit described above, the method comprising:

[0084] Step 100: Obtain the required output power and the output power of the bidirectional conversion circuit;

[0085] Step 200: Determine the on / off state of each DC-DC main converter circuit based on the required output power and the output power.

[0086] In this embodiment, the on / off state of each DC-DC main converter circuit can be determined by comparing the required output power with the output power of the bidirectional converter circuit. This allows for the operation of either one DC-DC main converter circuit or at least two DC-DC main converter circuits, improving the ability to guarantee optimal output power under different conditions and meeting the requirements for dynamic output power control.

[0087] For example, the circuit structure and parameters of the DC-DC main converter circuit in this embodiment can also be different. For instance, the output power ratio of the first and second DC-DC main converter circuits can be set to 1:2 or other ratios. In actual use, the first and second DC-DC main converter circuits can be directly controlled and driven. When the first channel needs to be turned on, only the first DC-DC main converter circuit is driven with a PWM signal, while the second DC-DC main converter circuit has no PWM signal; or only the second DC-DC main converter circuit is driven with a PWM signal, while the first DC-DC main converter circuit has no PWM signal; or both DC-DC main converter circuits are driven with PWM signals, thus achieving the function of turning on only the first DC-DC main converter circuit, only the second DC-DC main converter circuit, or both DC-DC main converter circuits. For DC-DC main converter circuits with more channels, the on / off state of each DC-DC main converter circuit can be determined according to actual needs.

[0088] Optionally, step 200 includes:

[0089] Step 210: Compare the required output power with the output power available to determine the circuit combination of the DC-DC main converter circuit that can meet the required output power.

[0090] Step 220: Determine the on / off state of each DC-DC main converter circuit based on the circuit combination.

[0091] In this embodiment, the output power of the bidirectional converter circuit can be stored in advance in the bidirectional converter circuit in the form of a table. The output power to be demanded is compared with the output power to be output to determine the circuit combination of DC-DC main converter circuit that can meet the output power to be demanded. Here, the on / off state of each DC-DC main converter circuit is determined with the optimal output power combination.

[0092] Specifically, taking the parallel operation of two DC-DC main converter circuits as an example, if the maximum output power of a single DC-DC main converter circuit is 1.8kW, and the highest efficiency is achieved at a design value of 65A with a 14V output, then the maximum output power of two DC-DC main converter circuits connected in parallel is 3.6kW, with the highest efficiency at 130A. When the system using the bidirectional converter circuit operates, if the output current is below 65A, the optimal efficiency is determined to be achieved with one DC-DC main converter circuit; if the output current is above 130A, the optimal efficiency is determined to be achieved with two DC-DC main converter circuits; when the current is between 65A and 130A, the operating mode can be switched between one or two DC-DC main converter circuits based on the actual measured efficiency value to achieve optimal efficiency.

[0093] It should be noted that, when the method of this application embodiment is applied, the required output power and the output power are compared, and the efficiency of each DC-DC main converter circuit is dynamically queried under the same current output condition, whether using a single DC-DC main converter circuit or several DC-DC main converter circuits connected in parallel is the most efficient.

[0094] Optionally, when the bidirectional conversion circuit includes a controller and a detection circuit connected to the controller; and the detection circuit is further connected to a first conversion circuit and a second conversion circuit of each of the DC-DC main conversion circuits, the method further includes:

[0095] Step 310: Obtain the detection signal detected by the detection circuit for each of the DC-DC main converter circuits;

[0096] Step 320: Determine the fault condition of the corresponding DC-DC main converter circuit based on the detection signal;

[0097] Step 330: If the fault condition of the corresponding DC-DC main converter circuit is a faulty circuit, then disconnect the power switch of the corresponding DC-DC main converter circuit; otherwise, close the power switch of the corresponding DC-DC main converter circuit.

[0098] In this embodiment, at least two DC-DC main converter circuits are connected in parallel for output. When a DC-DC main converter circuit fails, the power switching device on the output side of the DC-DC main converter circuit is turned off, and the power switching device on the input side is disconnected. This disconnects the faulty DC-DC main converter circuit from the bidirectional converter circuit, preventing the faulty DC-DC main converter circuit from affecting the overall output of the bidirectional converter circuit and ensuring that the other DC-DC main converter circuits of the bidirectional converter circuit continue to work.

[0099] Optionally, the method further includes:

[0100] Step 410: Obtain the power transmission direction of the DC-DC main converter circuit and the connection status of the external terminals of the second converter circuit of the DC-DC main converter circuit.

[0101] Step 420: Determine the on / off state of each DC-DC main converter circuit based on the connection status of the external terminal and the power transmission direction.

[0102] In this embodiment, the on / off state of each DC-DC main converter circuit is determined according to the connection status of the external terminal and the power transmission direction. This ensures the working state of each DC-DC main converter circuit under both forward and reverse transmission conditions, thereby guaranteeing working efficiency, enhancing system reliability, and avoiding control complexity.

[0103] Combination Figure 2 As shown, optionally, when the external terminals of the second conversion circuit are connected to an external power supply and a load, step 420 includes:

[0104] Step 421: When the power transmission direction of the bidirectional conversion circuit is from the second conversion circuit connected to the external power supply to the second conversion circuit connected to the load, the first conversion circuit of each DC-DC main conversion circuit is controlled to be in an open state, and the second conversion circuit connected to the external power supply and the second conversion circuit connected to the load are in a closed state.

[0105] In this embodiment, when the bidirectional conversion circuit is operating in charging mode, Figure 2 The PFM frequency adjustment method controls the disconnection of (Q1, Q2, Q3, Q4), and then controls the second conversion circuit connected to the external power supply and the second conversion circuit connected to the load respectively, so that the external power supply can transmit energy through the second conversion circuit connected to the external power supply and the second conversion circuit connected to the load, so that the external power supply can transmit energy to the load.

[0106] Step 421: When the power transmission direction of the bidirectional conversion circuit is from the first conversion circuit connected to the high-voltage power battery to the second conversion circuit connected to the load, the second conversion circuit connected to the external power source of each DC-DC main conversion circuit is controlled to be in an open state, while the first conversion circuit and the second conversion circuit connected to the load are in a closed state.

[0107] In this embodiment, Figure 2The PFM frequency adjustment method controls the disconnection of (Q5, Q6, Q7, Q8). When the bidirectional conversion circuit is working in charging mode, it controls the first conversion circuit and the second conversion circuit connected to the load respectively, so that the high-voltage power battery can transmit energy through the first conversion circuit and the second conversion circuit connected to the load, so that the high-voltage power battery can transmit energy to the load.

[0108] Step 423: When the power transmission direction of the bidirectional conversion circuit is from the first conversion circuit to the second conversion circuit connected to the external power supply, control the second conversion circuit connected to the load of each DC-DC main conversion circuit to be in an open state, and the first conversion circuit and the second conversion circuit connected to the external power supply to be in a closed state.

[0109] In this embodiment, when the bidirectional conversion circuit is operating in charging mode, Figure 2 The PFM frequency regulation method controls the disconnection of (Q11, Q12, Q13, Q14), and then controls the second conversion circuit and the first conversion circuit connected to the external power source respectively, so that the high-voltage power battery can transmit energy through the first conversion circuit and the second conversion circuit connected to the external power source, so that the high-voltage power battery can transmit energy to the external power source.

[0110] Therefore, the bidirectional converter circuit features a highly integrated design, resulting in a lightweight design that improves DC / DC conversion efficiency. It also incorporates an inverter discharge function, enhancing the user experience.

[0111] In summary, the method of this application adopts the parallel output of the bidirectional conversion circuit, which integrates at least the DC-DC main conversion circuit with external power supply function. This enables the bidirectional conversion circuit to simultaneously realize the DC / DC conversion function and the external power supply function, thereby improving the reliability of the system operation in the external power supply mode. At the same time, it achieves the optimal efficiency operation of the bidirectional conversion circuit and avoids the problem of low efficiency of existing DC / DC converters.

[0112] like Figure 4 As shown, this application provides an energy transmission control device applied to the bidirectional conversion circuit described above. The device includes:

[0113] The acquisition module 10 is used to acquire the required output power and the output power of the bidirectional conversion circuit;

[0114] The determination module 20 is used to determine the on / off state of each DC-DC main converter circuit based on the required output power and the output power.

[0115] Optionally, the determining module 20 includes:

[0116] The first determining unit is used to compare the required output power with the output power available to be output, and to determine the circuit combination of the DC-DC main converter circuit that can meet the required output power.

[0117] The second determining unit is used to determine the on / off state of each DC-DC main converter circuit based on the circuit combination.

[0118] Optionally, the device further includes:

[0119] The second acquisition module is used to acquire the detection signal detected by the detection circuit for each of the DC-DC main converter circuits;

[0120] The second determining module is used to determine the fault condition of the corresponding DC-DC main converter circuit based on the detection signal.

[0121] The processing module is configured to, if the fault condition of the corresponding DC-DC main converter circuit is a fault circuit, disconnect the power switch of the corresponding DC-DC main converter circuit; otherwise, close the power switch of the corresponding DC-DC main converter circuit.

[0122] Optionally, the device further includes:

[0123] The third acquisition module is used to acquire the power transmission direction of the DC-DC main converter circuit and the connection status of the external terminals of the second converter circuit of the DC-DC main converter circuit.

[0124] The third determining module is used to determine the on / off state of each DC-DC main converter circuit based on the connection status of the external terminal and the power transmission direction.

[0125] Optionally, the third determining module includes:

[0126] The first control unit is configured to control the first converter of each DC-DC main converter to be in an open state and the second converter connected to the external power supply and the second converter connected to the load to be in a closed state when the power transmission direction of the bidirectional converter is from the second converter connected to the external power supply to the second converter connected to the load.

[0127] The second control unit is configured to, when the power transmission direction of the bidirectional conversion circuit is from the first conversion circuit connected to the high-voltage power battery to the second conversion circuit connected to the load, control the second conversion circuit of each DC-DC main conversion circuit connected to the external power source to be in a disconnected state, and the first conversion circuit and the second conversion circuit connected to the load to be in a closed state.

[0128] The third control unit is configured to, when the power transmission direction of the bidirectional conversion circuit is from the first conversion circuit to the second conversion circuit connected to the external power supply, control the second conversion circuit of each DC-DC main conversion circuit connected to the load to be in a disconnected state, and the first conversion circuit and the second conversion circuit connected to the external power supply to be in a closed state.

[0129] In summary, the method and apparatus of this application have an integrated circuit and control method for DC / DC and external power supply functions. By using at least two DC / DC main conversion circuits in parallel, the reliability of external power supply is ensured. By using at least two DC / DC main conversion circuits, the on / off state of each DC-DC main conversion circuit can be determined according to the required output power, thereby improving the efficiency of the DC / DC converter.

[0130] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0131] The above describes the preferred embodiments of this application. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles described in this application, and these improvements and modifications are also within the protection scope of this application.

Claims

1. A bidirectional conversion circuit, characterized in that, include: At least two DC / DC-DC main converter circuits; Each of the aforementioned DC-DC main converter circuits includes: A transformer, a first conversion circuit, and a second conversion circuit; wherein, a first terminal of the first conversion circuit is connected to a first connection terminal of the transformer, and at least two first terminals of the second conversion circuits are connected to a second connection terminal of the transformer; In each of the DC-DC main converter circuits, the first converter circuit is connected to the high-voltage power battery, and the second converter circuit is connected to an external terminal; the external terminal is connected to an external power source and a load. Wherein, the second terminal of the first converter circuit of the DC-DC main converter circuit is connected to the high-voltage power battery and the second terminal of the first converter circuit of another DC-DC main converter circuit; the second terminal of the second converter circuit of the DC-DC main converter circuit is connected to the load and the second terminal of the second converter circuit of another DC-DC main converter circuit. The second conversion circuit of the DC-DC main converter circuit includes: a first winding control circuit and a first resonant circuit; the first resonant circuit is connected to the first winding control circuit and the external power supply respectively; the first winding control circuit is also connected to the second connection terminal of the transformer of the DC-DC main converter circuit; the second conversion circuit of another DC-DC main converter circuit includes: a second winding control circuit; the second winding control circuit is connected to the second connection terminal of the transformer of the other DC-DC main converter circuit and the first winding control circuit respectively; the first winding control circuit and the second winding control circuit have the same structure; The first conversion circuit includes: a first power switch (Q1), a second power switch (Q2), a third power switch (Q3), and a fourth power switch (Q4); the first power switch (Q1) and the third power switch (Q3) constitute a first bridge arm; the second power switch (Q2) and the fourth power switch (Q4) constitute a second bridge arm; the first conversion circuit further includes: a first capacitor and a first inductor; the connection terminal between the first power switch (Q1) and the third power switch (Q3) is connected to one end of a series circuit of the first capacitor and the first inductor; the other end of the series circuit is connected to a first connection terminal of the transformer; the first connection terminal of the transformer is also connected to the connection terminal between the second power switch (Q2) and the fourth power switch (Q4); The first resonant circuit of the second conversion circuit connected to the external power supply includes: a fifth power switch (Q5), a sixth power switch (Q6), a seventh power switch (Q7), and an eighth power switch (Q8); the fifth power switch (Q5) and the seventh power switch (Q7) constitute the third bridge arm; the sixth power switch (Q6) and the eighth power switch (Q8) constitute the fourth bridge arm; the first resonant circuit includes: a second capacitor and a second inductor; The second winding control circuit of the second conversion circuit connected to the external power supply includes: a ninth power switch (Q9) and a tenth power switch (Q10); one end of the ninth power switch (Q9) and one end of the tenth power switch (Q10) are respectively connected to the second connection terminal of the transformer; the other end of the ninth power switch (Q9) and the other end of the tenth power switch (Q10) are respectively connected to the first resonant circuit; the first resonant circuit is connected at the connection point between the two ends of the secondary winding of the transformer; when the ninth power switch is closed and the tenth power switch is open, the second conversion circuit and the ninth power switch form a first preset winding; when the ninth power switch is open and the tenth power switch is closed, the second conversion circuit and the tenth power switch form a second preset winding. The second conversion circuit connecting the load includes: an eleventh power switch (Q11), a twelfth power switch (Q12), a thirteenth power switch (Q13), a fourteenth power switch (Q14), a third inductor (L4), a third capacitor (C3), and a first freewheeling diode (D1); one end of the eleventh power switch (Q11) and one end of the twelfth power switch (Q12) are respectively connected to the two ends of the other secondary winding of the transformer; the other end of the eleventh power switch (Q11) and the other end of the twelfth power switch (Q12) are connected together; one end of the thirteenth power switch (Q13) is connected to the other secondary winding. The connection points between the two ends of the winding are connected; one end of the third inductor (L4) is connected to the other end of the thirteenth power switch (Q13); one end of the fourteenth power switch (Q14) is connected to the other end of the third inductor (L4), and the other end of the fourteenth power switch (Q14) is connected to one end of the load; one end of the third capacitor (C3) is connected to one end of the thirteenth power switch (Q13); the cathode of the first freewheeling diode (D1) is connected to the other end of the thirteenth power switch (Q13); and the other end of the third capacitor (C3) is connected to the anode of the first freewheeling diode (D1).

2. The bidirectional conversion circuit according to claim 1, characterized in that, Also includes: A controller and a detection circuit connected to the controller; The detection circuit is also connected to the first and second conversion circuits of each of the DC-DC main conversion circuits. The controller receives the detection signal from each DC-DC main converter circuit detected by the detection circuit, and uses it to determine the fault condition of each DC-DC main converter circuit and control the power switch of each DC-DC main converter circuit to turn on and off.

3. An energy transfer control method, characterized in that, Applied to the bidirectional converter circuit as described in any one of claims 1 to 2, the method comprises: Obtain the required output power and the output power of the bidirectional conversion circuit; The on / off state of each DC-DC main converter circuit is determined based on the required output power and the output power.

4. The method according to claim 3, characterized in that, The step of determining the on / off state of each DC-DC main converter circuit based on the required output power and the outputtable power includes: By comparing the required output power with the output power available, a circuit combination of DC-DC main converter circuits that can meet the required output power is determined. Based on the circuit combination, determine the on / off state of each DC-DC main converter circuit.

5. The method according to claim 3, characterized in that, The bidirectional conversion circuit includes a controller and a detection circuit connected to the controller; when the detection circuit is also connected to a first conversion circuit and a second conversion circuit of each of the DC-DC main conversion circuits, the method further includes: The detection signal detected by the detection circuit for each of the DC-DC main converter circuits is obtained; Based on the detected signal, determine the fault condition of the corresponding DC-DC main converter circuit; If the fault condition of the corresponding DC-DC main converter circuit is a faulty circuit, then the power switch of the corresponding DC-DC main converter circuit is disconnected; otherwise, the power switch of the corresponding DC-DC main converter circuit is closed.

6. The method according to claim 3, characterized in that, The method further includes: Obtain the power transmission direction of the DC-DC main converter circuit, and the connection status of the external terminals of the second converter circuit of the DC-DC main converter circuit; The on / off state of each DC-DC main converter circuit is determined based on the connection status of the external terminals and the power transmission direction.

7. The method according to claim 6, characterized in that, When the external terminals of the second conversion circuit are connected to an external power supply and a load, The step of determining the on / off state of each DC-DC main converter circuit based on the connection status of the external terminal and the power transmission direction includes: When the power transmission direction of the bidirectional conversion circuit is from the second conversion circuit connected to the external power supply to the second conversion circuit connected to the load, the first conversion circuit of each DC-DC main conversion circuit is controlled to be in an open state, and the second conversion circuit connected to the external power supply and the second conversion circuit connected to the load are in a closed state. When the power transmission direction of the bidirectional conversion circuit is from the first conversion circuit connected to the high-voltage power battery to the second conversion circuit connected to the load, the second conversion circuit connected to the external power source in each DC-DC main conversion circuit is controlled to be in an open state, while the first conversion circuit and the second conversion circuit connected to the load are in a closed state. When the power transmission direction of the bidirectional conversion circuit is from the first conversion circuit connected to the high-voltage power battery to the second conversion circuit connected to the external power source, the second conversion circuit connected to the load of each DC-DC main conversion circuit is controlled to be in an open state, while the first conversion circuit and the second conversion circuit connected to the external power source are in a closed state.

8. An energy transmission control device, applied to the bidirectional conversion circuit as described in any one of claims 1 to 2, characterized in that, The device includes: The acquisition module is used to acquire the required output power and the output power of the bidirectional conversion circuit. The determination module is used to determine the on / off state of each DC-DC main converter circuit based on the required output power and the output power.

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