Bidirectional resonant converter

Abstract

The utility model provides a bidirectional resonant converter, the bidirectional resonant converter comprises a Buck-Boost conversion module and a CLLLC conversion module, the CLLLC conversion module adopts a double resonant cavity structure with primary sides connected in series and secondary sides connected in parallel, the Buck-Boost conversion module is connected to a battery through the CLLLC conversion module, and the Buck-Boost conversion module is also connected to an external interface terminal. Through the CLLLC conversion module with the primary side connected in series and the secondary side connected in parallel, the branch current is reduced, the problem of heating caused by too high current of a single branch is solved, the output voltage range is enlarged through the Buck-Boost conversion module, and the requirements of electric equipment of different grades are met.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a bidirectional resonant converter. Background Art

[0002] In recent years, with the rapid development of new energy technologies, electric vehicles, electric boats and other means of transportation have been put into use in large quantities, with a high market share. Traditional charging piles cannot meet the various charging needs of new energy vehicles and boats, especially emergency charging. Mobile power supplies, as a portable power source, have penetrated into people's production and life, making it convenient for users to charge their devices anytime and anywhere. Based on this, portable, stackable and single-person-carrying mobile charging piles came into being.

[0003] In order to ensure that the mobile charging pile is small in size and highly stable, the entire power transmission system needs to adopt a suitable DC / DC converter. The soft switching performance and bidirectional energy flow capability of the traditional DC / DC converter are poor, while the resonant converter has excellent soft switching performance. Among them, the full-bridge bidirectional CLLLC resonant converter has the advantages of high efficiency, high power density, high reliability, etc., and is suitable for bidirectional high-power occasions.

[0004] Traditional bidirectional CLLLC resonant converters usually use a single resonant cavity structure, but as the power of the module increases significantly, the volume of the magnetic device also increases, and this traditional single resonant cavity is difficult to achieve high efficiency, high power density, and high reliability. Moreover, due to the limitations of its own structure, the CLLLC resonant converter only uses a one-stage full-bridge bidirectional CLLLC structure, which limits the range of output voltage and is not compatible with electrical equipment on different voltage platforms. Utility Model Content

[0005] In view of this, the purpose of the present application is to provide at least a bidirectional resonant converter, which reduces the branch current through a CLLLC conversion module with a primary side in series and a secondary side in parallel, solves the heating problem caused by excessive current in a single branch, and increases the output voltage range through a Buck-Boost conversion module to meet the needs of electrical equipment of different levels.

[0006] This application mainly includes the following aspects:

[0007] In a first aspect, an embodiment of the present application provides a bidirectional resonant converter, which includes a Buck-Boost conversion module and a CLLLC conversion module. The CLLLC conversion module adopts a dual resonant cavity structure with a primary side connected in series and a secondary side connected in parallel, wherein the Buck-Boost conversion module is connected to a battery through the CLLLC conversion module, and the Buck-Boost conversion module is also connected to an external interface terminal.

[0008] In one possible implementation, the CLLLC conversion module includes a first transformer, a second transformer, a first resonant control circuit, a second resonant control circuit and a third resonant control circuit, wherein the first resonant control circuit is respectively connected to the Buck-Boost conversion module, the primary positive pole of the first transformer and the primary negative pole of the second transformer, and the primary negative pole of the first transformer is connected to the primary positive pole of the second transformer; the secondary winding of the first transformer is connected to the second resonant control circuit, the secondary winding of the second transformer is connected to the third resonant control circuit, and the second resonant control circuit and the third resonant control circuit are respectively connected to the battery.

[0009] In one possible implementation, the first resonant control circuit includes a first full-bridge circuit and a first resonant circuit, the second resonant control circuit includes at least one second full-bridge circuit and a second resonant circuit, the third resonant control circuit includes at least one third full-bridge circuit and a third resonant circuit, and the second full-bridge circuit and the third full-bridge circuit are connected in parallel, wherein the first full-bridge circuit is respectively connected to the Buck-Boost conversion module and the first resonant circuit, and the first resonant circuit is also respectively connected to the primary positive pole of the first transformer and the primary negative pole of the second transformer; the second resonant circuit is respectively connected to the secondary winding of the first transformer and the second full-bridge circuit, and the second full-bridge circuit is also connected to the battery and the low-voltage ground terminal; the third resonant circuit is respectively connected to the secondary winding of the second transformer and the third full-bridge circuit, and the third full-bridge circuit is also connected to the battery and the low-voltage ground terminal.

[0010] In one possible implementation, the first full-bridge circuit includes a first control switch, a second control switch, a third control switch and a fourth control switch, and the first resonant circuit includes a first inductor and a first capacitor, wherein the first control switch is connected to the third control switch with a common drain and then connected to the Buck-Boost conversion module, and the second control switch is connected to the fourth control switch with a common source and then connected to the Buck-Boost conversion module and the high-voltage ground terminal, respectively; the source of the first control switch and the drain of the second control switch are connected to form a first bridge arm, and the source of the third control switch and the drain of the fourth control switch are connected to form a second bridge arm; the primary positive electrode of the first transformer is connected to the midpoint of the first bridge arm, the primary negative electrode of the first transformer is connected to the primary positive electrode of the second transformer, the primary negative electrode of the second transformer is connected to one end of the first capacitor, the other end of the first capacitor is connected to one end of the first inductor, and the other end of the first inductor is connected to the midpoint of the second bridge arm.

[0011] In one possible implementation, the Buck-Boost conversion module includes a fifth control switch, a sixth control switch, a seventh control switch, an eighth control switch and a second inductor, wherein the drain of the fifth control switch is connected to an external interface terminal, the sixth control switch and the eighth control switch are connected to the external interface terminal, the high voltage ground terminal, the common source terminal between the second control switch and the fourth control switch after the common source is connected, and the drain of the seventh control switch is connected to the common drain terminal between the first control switch and the second control switch; the source of the fifth control switch and the drain of the sixth control switch are connected to form a third bridge arm, the source of the seventh control switch and the drain of the eighth control switch are connected to form a fourth bridge arm, and the two ends of the second inductor are respectively connected to the midpoint of the third bridge arm and the midpoint of the fourth bridge arm.

[0012] In a possible implementation, the second resonant circuit includes a third inductor and a second capacitor, the second full-bridge circuit includes a ninth control switch, a tenth control switch, an eleventh control switch and a twelfth control switch, the third inductor is placed inside the first transformer, wherein the source of the ninth control switch is connected to the drain of the tenth control switch to form a fifth bridge arm, the source of the eleventh control switch is connected to the drain of the twelfth control switch to form a sixth bridge arm, the ninth control switch and the eleventh control switch are connected together with their drain, and then connected to the third full-bridge circuit and the positive electrode of the battery in the third resonant control circuit, and the tenth control switch and the twelfth control switch are connected together with their source, and then connected to the low-voltage ground terminal, the third full-bridge circuit and the negative electrode of the battery; one end of the third inductor is connected to one end of the secondary winding of the first transformer, the other end of the third inductor is connected to one end of the second capacitor, the other end of the second capacitor is connected to the midpoint of the fifth bridge arm, and the other end of the secondary winding of the first transformer is connected to the midpoint of the sixth bridge arm.

[0013] In a possible implementation, the third resonant circuit includes a fourth inductor and a third capacitor, the third full-bridge circuit includes a thirteenth control switch, a fourteenth control switch, a fifteenth control switch and a sixteenth control switch, and the fourth inductor is placed inside the second transformer, wherein the source of the thirteenth control switch is connected to the drain of the fourteenth control switch to form a seventh bridge arm, the source of the fifteenth control switch is connected to the drain of the sixteenth control switch to form an eighth bridge arm, the thirteenth control switch and the fifteenth control switch are connected to the common drain terminal in the second resonant control circuit and the positive electrode of the battery after the common drain of the thirteenth control switch is connected to the fifteenth control switch, and the fourteenth control switch and the sixteenth control switch are connected to the low-voltage ground terminal, the common source terminal in the second resonant control circuit and the negative electrode of the battery after the common source of the fourteenth control switch is connected; one end of the fourth inductor is connected to one end of the secondary winding of the second transformer, the other end of the fourth inductor is connected to one end of the third capacitor, the other end of the third capacitor is connected to the midpoint of the seventh bridge arm, and the other end of the secondary winding of the second transformer is connected to the midpoint of the eighth bridge arm.

[0014] In one possible implementation, the bidirectional resonant converter further includes an EMC circuit, a first protection circuit, a second protection circuit and a pre-charging circuit, the EMC circuit is connected to the external interface terminal through a load access switch, the first protection circuit is connected to the EMC circuit; the first protection circuit is connected in parallel between the Buck-Boost conversion module and the EMC circuit; the second protection circuit is connected in parallel between the Buck-Boost conversion module and the CLLLC conversion module; the CLLLC conversion module is connected to the battery through the pre-charging circuit.

[0015] In one possible implementation, the EMC circuit includes a fourth capacitor, a fifth capacitor, a first filter inductor, and a second filter inductor, wherein one end of the load access switch is connected to the positive electrode interface of the external interface terminal, the other end of the load access switch is respectively connected to one end of the fourth capacitor and the first connection end of the first filter inductor, the other end of the fourth capacitor is connected to the second connection end of the first filter inductor, the third connection end of the first filter inductor is connected to one end of the fifth capacitor and the first connection end of the second filter inductor, the fourth connection end of the first filter inductor is connected to the other end of the fifth capacitor and the second connection end of the second filter inductor; the third connection end of the second filter inductor is connected to the drain of the fifth control switch in the first protection circuit and the Buck-Boost conversion module, and the fourth connection end of the second filter inductor is connected to the common source terminal in the first protection circuit and the Buck-Boost conversion module.

[0016] In one possible implementation, the first protection circuit includes a sixth capacitor, a seventh capacitor and a first resistor, wherein one end of the sixth capacitor is respectively connected to the third connection terminal of the second filter inductor, one end of the seventh capacitor and the drain of the fifth control switch, the other end of the sixth capacitor is respectively connected to the fourth connection terminal of the second filter inductor and one end of the first resistor, and the other end of the first resistor is respectively connected to the other end of the seventh capacitor and the common source terminal in the Buck-Boost conversion module.

[0017] In one possible implementation, the second protection circuit includes at least one eighth capacitor connected in parallel and at least one ninth capacitor and a second resistor connected in parallel, wherein one end of the eighth capacitor is respectively connected to one end of the ninth capacitor, the drain of the seventh control switch in the Buck-Boost conversion module, and the common drain terminal of the first full-bridge circuit in the CLLLC conversion module; the other end of the eighth capacitor is respectively connected to one end of the second resistor and the common source terminal in the Buck-Boost conversion module, and the other end of the second resistor is respectively connected to the other end of the ninth capacitor and the common source terminal of the first full-bridge circuit in the CLLLC conversion module.

[0018] In one possible implementation, the pre-charging circuit includes at least one tenth capacitor connected in parallel, at least one seventeenth control switch connected in parallel and a third resistor, wherein one end of the tenth capacitor is respectively connected to the common drain terminal and the positive electrode of the battery corresponding to the second full-bridge circuit and the third full-bridge circuit of the CLLLC conversion module, the other end of the tenth capacitor is connected to the drain of the seventeenth control switch, the source of the seventeenth control switch is respectively connected to one end of the third resistor and the common source terminal corresponding to the second full-bridge circuit and the third full-bridge circuit of the CLLLC conversion module, and the other end of the third resistor is connected to the negative electrode of the battery.

[0019] A bidirectional resonant converter provided in an embodiment of the present application includes a Buck-Boost conversion module and a CLLLC conversion module. The CLLLC conversion module adopts a dual resonant cavity structure with a primary side connected in series and a secondary side connected in parallel, wherein the Buck-Boost conversion module is connected to a battery through the CLLLC conversion module, and the Buck-Boost conversion module is also connected to an external interface terminal. The present application reduces branch currents and solves the heating problem caused by excessive current in a single branch through a CLLLC conversion module with a primary side connected in series and a secondary side connected in parallel, and increases the output voltage range through a Buck-Boost conversion module to meet the needs of electrical equipment of different levels.

[0020] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A structural diagram of a bidirectional portable movable charging station provided in an embodiment of the present application is shown;

[0023] Figure 2 One of the structural diagrams of a bidirectional resonant converter provided in an embodiment of the present application is shown;

[0024] Figure 3 A second structural diagram of a bidirectional resonant converter provided in an embodiment of the present application is shown;

[0025] Figure 4 A third topology diagram of a bidirectional resonant converter provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0026] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art, under the guidance of the content of the present application, can add one or more other operations to the flowchart, or remove one or more operations from the flowchart.

[0027] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0028] In recent years, with the rapid development of new energy technologies, electric vehicles, electric boats and other means of transportation have been put into use in large quantities, with a high market share. Traditional charging piles cannot meet the various charging needs of new energy vehicles and boats, especially emergency charging. Mobile power supplies, as a portable power source, have penetrated into people's production and life, making it convenient for users to charge their devices anytime and anywhere. Portable, stackable and single-person-carrying mobile charging piles have emerged.

[0029] In order to ensure that the mobile charging pile is small in size and highly stable, the entire power transmission system needs to use a suitable DC / DC converter. The soft switching performance and bidirectional energy flow capability of the traditional DC / DC converter are poor, while the resonant converter has excellent soft switching performance. Among them, the full-bridge bidirectional CLLLC resonant converter has the advantages of high efficiency, high power density, high reliability, etc., and is suitable for bidirectional high-power occasions.

[0030] Traditional bidirectional CLLLC resonant converters usually adopt a single resonant cavity structure, but as the module power increases significantly, the size of the magnetic device is also increasing. To achieve high efficiency, high power density and high reliability, this traditional single resonant cavity is difficult to achieve. Moreover, due to its own structural limitations, the CLLLC resonant converter only uses a one-stage full-bridge bidirectional CLLLC structure, and the output voltage range is limited, making it incompatible with electrical equipment on different voltage platforms.

[0031] Based on this, the embodiment of the present application provides a bidirectional resonant converter, which reduces the branch current through the CLLLC conversion module with the primary side connected in series and the secondary side connected in parallel, solves the heating problem caused by the excessive current of a single branch, and increases the output voltage range through the Buck-Boost conversion module to meet the needs of different levels of electrical equipment, as follows:

[0032] See also Figure 1 , Figure 1 The structure diagram of a bidirectional portable removable charging station provided in an embodiment of the present application is shown. Figure 1 As shown, the bidirectional portable movable charging pile includes an external interface terminal 1, a bidirectional resonant converter 2 and a battery 3 connected in sequence, wherein the bidirectional resonant converter 2 includes a Buck-Boost conversion module 21 and a CLLLC conversion module 22. Specifically, the external interface terminal 1 is connected to the battery 3 through the Buck-Boost conversion module 21 and the CLLLC conversion module 22 in sequence, and the external interface terminal 1 can be connected to the charging gun head and the DC power supply. According to different working modes, different load interfaces can be selected for connection. The CLLLC conversion module adopts a dual-resonance cavity structure with the primary side in series and the secondary side in parallel.

[0033] In a preferred embodiment, the working mode of the bidirectional portable mobile charging pile includes a discharge mode and a charging mode. When the external interface terminal 1 is connected to the charging gun head, the charging gun head is connected to an electrical device such as a new energy vehicle. At this time, the discharge mode is started, and the battery begins to discharge the electrical device. The battery voltage is converted into a DC high voltage of about 360V by the CLLLC conversion module 22, and then converted into a first preset output voltage by the Buck-Boost conversion module 21. The output voltage ranges from 200V to 500V, and the output voltage is used to charge the electrical device. This process is to transfer the electricity stored in the battery 3 of the bidirectional portable mobile charging pile to the battery of the electrical device. It is a discharge process of the bidirectional portable mobile charging pile and also a charging process of the electrical device.

[0034] When the external interface terminal 1 is connected to a DC power supply, the charging mode is started, and the DC power supply starts to charge the battery 3. It is converted into an output voltage of about 360V by the Buck-Boost conversion module 21, and then converted into a second preset output voltage by the CLLLC conversion module 22. The output voltage charges the battery 3. This process is to transfer the electricity stored in the DC power supply to the battery of the bidirectional portable movable charging pile. It is the discharge process of the DC power supply and also the charging process of the battery 3.

[0035] See also Figure 2 , Figure 2 FIG. 1 shows one of the structural diagrams of a bidirectional resonant converter provided in an embodiment of the present application. Figure 2 As shown, the CLLLC conversion module includes a first transformer T1, a second transformer T2, a first resonant control circuit 221, a second resonant control circuit 222 and a third resonant control circuit 223, wherein the first resonant control circuit 221 is respectively connected to the Buck-Boost conversion module 21, the primary positive pole of the first transformer T1 and the primary negative pole of the second transformer T2, the primary negative pole of the first transformer T1 is connected to the primary positive pole of the second transformer T2, the secondary winding of the first transformer T1 is connected to the second resonant control circuit 222, the secondary winding of the second transformer T2 is connected to the third resonant control circuit 223, and the second resonant control circuit 222 and the third resonant control circuit 223 are respectively connected to the battery 3.

[0036] like Figure 2 As shown, the bidirectional resonant converter also includes an EMC circuit 23, a first protection circuit 24, a second protection circuit 25 and a pre-charging circuit 26. The external interface terminal 1 is connected to the Buck-Boost conversion module 21 through the EMC circuit 23 and the first protection circuit 24 in sequence. The Buck-Boost conversion module 21 is connected to the CLLLC conversion module 22 through the second protection circuit 25. The CLLLC conversion module 22 is connected to the battery 3 through the pre-charging circuit 26. The first protection circuit 24 is connected in parallel between the Buck-Boost conversion module 21 and the EMC23 circuit, and the second protection circuit 25 is connected in parallel between the Buck-Boost conversion module 21 and the CLLLC conversion module 22.

[0037] See also Figure 3 , Figure 3 FIG. 2 shows a second structural diagram of a bidirectional resonant converter provided in an embodiment of the present application. Figure 3As shown, the first resonant control circuit 221 includes a first full-bridge circuit 2210 and a first resonant circuit 2211, the second resonant control circuit 222 includes a second full-bridge circuit 2220 and a second resonant circuit 2221, and the third resonant control circuit 223 includes a third full-bridge circuit 2230 and a third resonant circuit 2231. Specifically, in actual use, based on the limitations of various parameters of the control switch, the first full-bridge circuit 2210 can be composed of multiple full-bridge circuits in parallel to reduce the current in a single branch, thereby reducing heat. Similarly, the second full-bridge circuit can also be composed of multiple full-bridge circuits in parallel, which will not be elaborated here.

[0038] Specifically, the first full-bridge circuit 2210 is respectively connected to the Buck-Boost conversion module 21 and the first resonant circuit 2211, the first resonant circuit 2211 is also respectively connected to the primary positive pole of the first transformer T1 and the primary negative pole of the second transformer T2, the second resonant circuit 2221 is respectively connected to the secondary winding of the first transformer T1 and the second full-bridge circuit 2220, the second full-bridge circuit 2220 is also connected to the battery 3 and the low-voltage ground terminal GNDL through the pre-charging circuit 26, the third resonant circuit 2231 is respectively connected to the secondary side of the second transformer T2 and the third full-bridge circuit 2230, the third full-bridge circuit 2230 is also connected to the battery 3 and the low-voltage ground terminal GNDL through the pre-charging circuit 26.

[0039] See also Figure 4 , Figure 4 FIG3 shows a topology diagram of a bidirectional resonant converter provided in an embodiment of the present application. Figure 4 As shown, the EMC circuit 23 includes a fourth capacitor C4, a fifth capacitor C5, a first filter inductor L5 and a second filter inductor L6.

[0040] The first protection circuit 24 includes a sixth capacitor C6, a seventh capacitor C7 and a first resistor R1.

[0041] The Buck-Boost conversion module 21 includes a fifth control switch Q5 , a sixth control switch Q6 , a seventh control switch Q7 , an eighth control switch Q8 and a second inductor L2 .

[0042] The second protection circuit 25 includes an eighth capacitor C8, a ninth capacitor C9 and a second resistor R2. In practical applications, the second protection circuit can be formed by a plurality of aluminum electrolytic capacitors connected in parallel.

[0043] The first full-bridge circuit 2210 includes a first control switch Q1 , a second control switch Q2 , a third control switch Q3 and a fourth control switch Q4 , and the first resonant circuit 2211 includes a first inductor L1 and a first capacitor C1 .

[0044] The second resonant circuit 2221 includes a third inductor L3 and a second capacitor C2, the second full-bridge circuit 2220 includes a ninth control switch Q9, a tenth control switch Q10, an eleventh control switch Q11 and a twelfth control switch Q12, the third resonant circuit package 2231 includes a fourth inductor L4 and a third capacitor C3, the third full-bridge circuit 2230 includes a thirteenth control switch Q13, a fourteenth control switch Q14, a fifteenth control switch Q15 and a sixteenth control switch Q16. To reduce the volume of magnetic components, the third inductor L3 and the fourth inductor L4 both adopt a magnetic integrated structure and are respectively placed in the first transformer T1 and the second transformer T2, that is, the third inductor L3 is connected in series with one end of the secondary winding of the first transformer T1 inside the first transformer T1, and the fourth inductor L4 is connected in series with the other end of the secondary winding of T2 inside the second transformer T2.

[0045] The pre-charging circuit 26 includes a tenth capacitor C10, a seventeenth control switch Q17 and a third resistor R3.

[0046] Specifically, for the EMC circuit 23, the positive electrode interface of the external interface terminal 1 is connected to one end of the load access switch K1, the other end of the load access switch K1 is respectively connected to one end of the fourth capacitor C4 and the first connection end of the first filter inductor L5, the other end of the fourth capacitor C4 is connected to the second connection end of the first filter inductor L5, the third connection end of the first filter inductor L5 is connected to one end of the fifth capacitor C5 and the first connection end of the second filter inductor L6, the fourth connection end of the first filter inductor L5 is connected to the other end of the fifth capacitor C5 and the second connection end of the second filter inductor L6, and the The three connection ends are connected to the first protection circuit 24 and the Buck-Boost conversion module 21, and the fourth connection end of the second filter inductor L6 is connected to the first protection circuit 24 and the Buck-Boost conversion module 21. In the present application, the fourth capacitor C4 and the fifth capacitor C5 are filter capacitors. In the present application, in order to enable the bidirectional resonant converter to pass the EMC certification, a two-stage filter circuit is specially designed to meet the certification requirements. Specifically, inside the EMC circuit 23, the fourth capacitor C4 and the first filter inductor L5 are used as the first-stage filter circuit, and the fifth capacitor C5 and the second filter inductor L6 are used as the second-stage filter circuit.

[0047] In a preferred embodiment, for the first protection circuit 24, one end of the sixth capacitor C6 is respectively connected to one end of the seventh capacitor C7, the third connection end of the second filter inductor L6 and the Buck-Boost conversion module 21, the other end of the sixth capacitor C6 is respectively connected to the fourth connection end of the second filter inductor L6 and one end of the first resistor R1, the other end of the first resistor R1 is respectively connected to the other end of the seventh capacitor C7 and the Buck-Boost conversion module 21, the first resistor R1 is a current sensing resistor, the sixth capacitor C6 is a DC-link film capacitor, and the seventh capacitor C7 is an aluminum electrolytic capacitor. In the present application, the sixth capacitor C6 and the seventh capacitor C7 are connected in parallel between the EMC circuit 23 and the Buck-Boost circuit, so that the DC high voltage output by the EMC circuit 23 passes through C3 and C4 and then connected to the Buck-Boost conversion module 21, which can effectively filter out noise and pulsation, and improve the stability and reliability of the output voltage. The first resistor R1 is connected in series between C6 and C7, and its function is to detect current and provide overcurrent protection, short circuit protection, etc. for the system.

[0048] For the Buck-Boost conversion module 21, the source of the fifth control switch Q5 and the drain of the sixth control switch Q6 are connected to form a third bridge arm, the source of the seventh control switch Q7 and the drain of the eighth control switch Q8 are connected to form a fourth bridge arm, and the two ends of the second inductor L2 are respectively connected to the midpoint of the third bridge arm and the midpoint of the fourth bridge arm.

[0049] The drain of the fifth control switch Q5 is respectively connected to one end of the sixth capacitor C6, one end of the seventh capacitor C7 and the third connection end of the second filter inductor L6, the drain of the seventh control switch Q7 is respectively connected to the second protection circuit 25 and the first full-bridge circuit 2210, and the sixth control switch Q6 and the eighth control switch Q8 are respectively connected to the other end of the first resistor R1, the high-voltage ground terminal GNDH, the second protection circuit 25 and the first full-bridge circuit 2210 after the common source is connected.

[0050] For the second protection circuit 25, one end of the eighth capacitor C8 is respectively connected to one end of the ninth capacitor C9, the drain of the seventh control switch Q7 and the common drain terminal of the first full-bridge circuit 2210, the other end of the eighth capacitor C8 is respectively connected to one end of the second resistor R2 and the common source terminal in the Buck-Boost conversion module 21, the other end of the second resistor R2 is respectively connected to the other end of the ninth capacitor C9 and the common source terminal of the first full-bridge circuit 2210, and the high-voltage ground terminal GNDH. The purpose of the eighth capacitor C8 and the ninth capacitor C9 is to obtain the capacitance and ripple current required by the system, so as to filter out the ripple voltage and output a smooth DC high voltage. The second resistor R2 is a current sensing resistor, and its function is to detect the current on the VPRI side to provide overcurrent protection, short circuit protection, etc. for the system. The VPRI side is the connection position corresponding to the Buck-Boost conversion module 21 and the first full-bridge circuit 2210. When the battery is discharged, VPRI is the output voltage corresponding to the first full-bridge circuit 2210, and when the battery is charged, VPRI is the output voltage corresponding to the Buck-Boost conversion module 21.

[0051] For the first full-bridge circuit 2210 and the first resonant circuit 2211, after the first control switch Q1 and the third control switch Q3 are connected in common with the drain, they are respectively connected to the drain of the seventh control switch Q7, one end of the eighth capacitor C8 and one end of the ninth capacitor C9; after the second control switch Q1 and the fourth control switch Q4 are connected in common with the source, they are respectively connected to the other end of the second resistor R2, the other end of the ninth capacitor C9 and the high-voltage ground terminal GNDH; the source of the first control switch Q1 and the drain of the second control switch Q2 are connected to form a first bridge arm; the source of the third control switch Q3 and the drain of the fourth control switch Q4 are connected to form a second bridge arm.

[0052] The primary positive electrode of the first transformer T1 is connected to the midpoint of the first bridge arm, the primary negative electrode of the first transformer T1 is connected to the primary positive electrode of the second transformer T2, the primary negative electrode of the second transformer T2 is connected to one end of the first capacitor C1, the other end of the first capacitor C1 is connected to one end of the first inductor L1, and the other end of the first inductor L2 is connected to the midpoint of the second bridge arm.

[0053] For the second full-bridge circuit 2220 and the second resonant circuit 2221, the second full-bridge circuit 2220 is formed by Q9, Q10, Q11 and Q12, the source of the ninth control switch Q9 is connected to the drain of the tenth control switch Q10 to form a fifth bridge arm, the source of the eleventh control switch Q11 is connected to the drain of the twelfth control switch Q12 to form a sixth bridge arm, the ninth control switch Q9 and the eleventh control switch Q11 are connected to the third full-bridge circuit 2230, the pre-charging circuit 26 and the positive electrode of the battery after the drain is connected, the tenth control switch Q10 and the twelfth control switch Q12 are connected to the low voltage ground terminal GNDL, the third full-bridge circuit 2230, the pre-charging circuit 26 and the negative electrode of the battery after the source is connected.

[0054] One end of the third inductor L3 is connected to one end of the secondary winding of the first transformer T1, the other end of the third inductor L3 is connected to one end of the second capacitor C2, the other end of the second capacitor C2 is connected to the midpoint of the fifth bridge arm, and the other end of the secondary winding of the first transformer T1 is connected to the midpoint of the sixth bridge arm.

[0055] For the third full-bridge circuit 2230 and the third resonant circuit 2231, the second third full-bridge circuit 2230 is formed by Q13, Q14, Q15 and Q16, the source of the thirteenth control switch Q13 is connected to the drain of the fourteenth control switch Q14 to form a seventh bridge arm, the source of the fifteenth control switch Q15 is connected to the drain of the sixteenth control switch Q16 to form an eighth bridge arm, the thirteenth control switch Q13 and the fifteenth control switch Q15 are connected to the common drain terminal in the second full-bridge circuit 2220, the pre-charge circuit 26 and the positive electrode of the battery after the common drain is connected, the fourteenth control switch Q14 and the sixteenth control switch Q16 are connected to the common source, and then connected to the low voltage ground terminal GNDL, the common source terminal in the second full-bridge circuit 2220, the pre-charge circuit 26 and the negative electrode of the battery.

[0056] For the pre-charging circuit 26, one end of the tenth capacitor C10 is respectively connected to the common drain terminal and the positive electrode of the battery corresponding to the second full-bridge circuit 2220 and the third full-bridge circuit 2230, the other end of the tenth capacitor C10 is connected to the drain of the seventeenth control switch Q17, the source of the seventeenth control switch Q17 is respectively connected to one end of the third resistor R3 and the common source terminal corresponding to the second full-bridge circuit 2220 and the third full-bridge circuit 2230, the other end of the third resistor R3 is connected to the negative electrode of the battery. The function of the pre-charging circuit 26 is to prevent the battery 3 from igniting during the plugging and unplugging process to improve safety. The third resistor R3 is a current sensing resistor, and its function is to detect the battery current and transmit the detected battery current to the multi-functional current detection discharger, so that the multi-functional current detection discharger can calculate the battery SOC, system power, etc. In the present application, as shown in the figure, the battery voltage is represented by VSEC.

[0057] The control terminals (gates) of all control switches in the present application are connected to a controller or a control chip to receive control signals transmitted by the controller or the control chip, thereby realizing on-off switching.

[0058] Taking the discharge mode as an example, the controller sends a conduction signal to the seventeenth control switch Q17. After the seventeenth control switch Q17 is turned on, the main power circuit corresponding to the bidirectional portable movable charging pile is turned on, and the battery 3 starts to discharge. The battery voltage is converted into a DC high voltage of about 360V through the second resonance control circuit 222 and the third resonance control circuit 223 connected in parallel, the first transformer T1 and the second transformer T2 connected in series, and the first resonance control circuit 221, and then through the filtering effect of the second protection circuit 25, it is input into the Buck-Boost conversion module 21 to be converted into a first preset output voltage. The first preset output voltage ranges from 200V to 500V. The first preset output voltage then passes through the filtering effect of the first protection circuit 24 and the EMC circuit 23 in turn, and the output voltage is given to the electrical equipment to charge the electrical equipment.

[0059] The charging mode is the opposite process of the above-mentioned discharging process. The principle is similar to that of the discharging mode and will not be elaborated here.

[0060] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the system and device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. In the several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0061] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0062] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0063] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0064] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A bidirectional resonant converter, characterized in that: The bidirectional resonant converter includes a Buck-Boost conversion module and a CLLLC conversion module. The CLLLC conversion module adopts a dual resonant cavity structure with a primary side connected in series and a secondary side connected in parallel. The Buck-Boost conversion module is connected to the battery through the CLLLC conversion module, and the Buck-Boost conversion module is also connected to the external interface terminal.

2. The bidirectional resonant converter according to claim 1, characterized in that: The CLLLC conversion module includes a first transformer, a second transformer, a first resonance control circuit, a second resonance control circuit and a third resonance control circuit. Wherein, the first resonant control circuit is respectively connected to the Buck-Boost conversion module, the primary positive electrode of the first transformer and the primary negative electrode of the second transformer, and the primary negative electrode of the first transformer is connected to the primary positive electrode of the second transformer; The secondary winding of the first transformer is connected to the second resonant control circuit, the secondary winding of the second transformer is connected to the third resonant control circuit, and the second resonant control circuit and the third resonant control circuit are respectively connected to the battery.

3. The bidirectional resonant converter according to claim 2, characterized in that: The first resonance control circuit includes a first full-bridge circuit and a first resonance circuit, the second resonance control circuit includes at least one second full-bridge circuit and a second resonance circuit, the third resonance control circuit includes at least one third full-bridge circuit and a third resonance circuit, the second full-bridge circuit and the third full-bridge circuit are connected in parallel, The first full-bridge circuit is connected to the Buck-Boost conversion module and the first resonant circuit respectively, and the first resonant circuit is also connected to the primary positive electrode of the first transformer and the primary negative electrode of the second transformer respectively; The second resonant circuit is respectively connected to the secondary winding of the first transformer and the second full-bridge circuit, and the second full-bridge circuit is also connected to the battery and a low-voltage ground terminal; The third resonant circuit is connected to the secondary winding of the second transformer and the third full-bridge circuit respectively, and the third full-bridge circuit is also connected to the battery and a low-voltage ground terminal.

4. The bidirectional resonant converter according to claim 3, characterized in that: The first full-bridge circuit includes a first control switch, a second control switch, a third control switch and a fourth control switch, the first resonant circuit includes a first inductor and a first capacitor, Wherein, after the first control switch and the third control switch are connected to a common drain, they are connected to the Buck-Boost conversion module; after the second control switch and the fourth control switch are connected to a common source, they are respectively connected to the Buck-Boost conversion module and the high-voltage ground terminal; The source of the first control switch and the drain of the second control switch are connected to form a first bridge arm, and the source of the third control switch and the drain of the fourth control switch are connected to form a second bridge arm; The primary positive pole of the first transformer is connected to the midpoint of the first bridge arm, the primary negative pole of the first transformer is connected to the primary positive pole of the second transformer, the primary negative pole of the second transformer is connected to one end of the first capacitor, the other end of the first capacitor is connected to one end of the first inductor, and the other end of the first inductor is connected to the midpoint of the second bridge arm.

5. The bidirectional resonant converter according to claim 4, characterized in that: The Buck-Boost conversion module includes a fifth control switch, a sixth control switch, a seventh control switch, an eighth control switch and a second inductor. The drain of the fifth control switch is connected to the external interface terminal, the sixth control switch and the eighth control switch are connected to the external interface terminal, the high voltage ground terminal, and the common source terminal between the second control switch and the fourth control switch after the common source terminals are connected, and the drain of the seventh control switch is connected to the common drain terminal between the first control switch and the second control switch; The source of the fifth control switch and the drain of the sixth control switch are connected to form a third bridge arm, the source of the seventh control switch and the drain of the eighth control switch are connected to form a fourth bridge arm, and the two ends of the second inductor are respectively connected to the midpoint of the third bridge arm and the midpoint of the fourth bridge arm.

6. The bidirectional resonant converter according to claim 3, characterized in that: The second resonant circuit includes a third inductor and a second capacitor, the second full-bridge circuit includes a ninth control switch, a tenth control switch, an eleventh control switch and a twelfth control switch, the third inductor is disposed inside the first transformer, Wherein, the source of the ninth control switch is connected to the drain of the tenth control switch to form a fifth bridge arm, the source of the eleventh control switch is connected to the drain of the twelfth control switch to form a sixth bridge arm, the ninth control switch is connected to the eleventh control switch through a common drain, and then connected to the third full-bridge circuit in the third resonant control circuit and the positive electrode of the battery, and the tenth control switch is connected to the twelfth control switch through a common source, and then connected to the low-voltage ground terminal, the third full-bridge circuit and the negative electrode of the battery; One end of the third inductor is connected to one end of the secondary winding of the first transformer, the other end of the third inductor is connected to one end of the second capacitor, the other end of the second capacitor is connected to the midpoint of the five bridge arms, and the other end of the secondary winding of the first transformer is connected to the midpoint of the six bridge arms.

7. The bidirectional resonant converter according to claim 3, characterized in that: The third resonant circuit includes a fourth inductor and a third capacitor, the third full-bridge circuit includes a thirteenth control switch, a fourteenth control switch, a fifteenth control switch and a sixteenth control switch, the fourth inductor is disposed inside the second transformer, The source of the thirteenth control switch is connected to the drain of the fourteenth control switch to form a seventh bridge arm, the source of the fifteenth control switch is connected to the drain of the sixteenth control switch to form an eighth bridge arm, the thirteenth control switch is connected to the fifteenth control switch with a common drain, and then connected to the common drain terminal in the second resonant control circuit and the positive electrode of the battery, and the fourteenth control switch is connected to the sixteenth control switch with a common source, and then connected to the low voltage ground terminal, the common source terminal in the second resonant control circuit and the negative electrode of the battery; One end of the fourth inductor is connected to one end of the secondary winding of the second transformer, the other end of the fourth inductor is connected to one end of the third capacitor, the other end of the third capacitor is connected to the midpoint of the seventh bridge arm, and the other end of the secondary winding of the second transformer is connected to the midpoint of the eighth bridge arm.

8. The bidirectional resonant converter according to claim 1, characterized in that: The bidirectional resonant converter further includes an EMC circuit, a first protection circuit, a second protection circuit and a pre-charging circuit. The EMC circuit is connected to the external interface terminal via a load access switch; The first protection circuit is connected to the EMC circuit; The first protection circuit is connected in parallel between the Buck-Boost conversion module and the EMC circuit; The second protection circuit is connected in parallel between the Buck-Boost conversion module and the CLLLC conversion module; The CLLLC conversion module is connected to the battery through the pre-charging circuit.

9. The bidirectional resonant converter according to claim 8, characterized in that: The EMC circuit includes a fourth capacitor, a fifth capacitor, a first filter inductor and a second filter inductor. Wherein, one end of the load access switch is connected to the positive electrode interface of the external interface terminal, the other end of the load access switch is respectively connected to one end of the fourth capacitor and the first connection end of the first filter inductor, the other end of the fourth capacitor is connected to the second connection end of the first filter inductor, the third connection end of the first filter inductor is connected to one end of the fifth capacitor and the first connection end of the second filter inductor, and the fourth connection end of the first filter inductor is connected to the other end of the fifth capacitor and the second connection end of the second filter inductor; The third connection end of the second filter inductor is connected to the drain of the first protection circuit and the fifth control switch in the Buck-Boost conversion module, and the fourth connection end of the second filter inductor is connected to the common source terminal of the first protection circuit and the Buck-Boost conversion module.

10. The bidirectional resonant converter according to claim 9, characterized in that: The first protection circuit includes a sixth capacitor, a seventh capacitor and a first resistor, Among them, one end of the sixth capacitor is respectively connected to the third connection end of the second filter inductor, one end of the seventh capacitor and the drain of the fifth control switch, the other end of the sixth capacitor is respectively connected to the fourth connection end of the second filter inductor and one end of the first resistor, and the other end of the first resistor is respectively connected to the other end of the seventh capacitor and the common source terminal in the Buck-Boost conversion module.

11. The bidirectional resonant converter according to claim 8, characterized in that: The second protection circuit includes at least one eighth capacitor connected in parallel and at least one ninth capacitor and a second resistor connected in parallel, Wherein, one end of the eighth capacitor is respectively connected to one end of the ninth capacitor, the drain of the seventh control switch in the Buck-Boost conversion module and the common drain end of the first full-bridge circuit in the CLLLC conversion module; The other end of the eighth capacitor is respectively connected to one end of the second resistor and the common source terminal in the Buck-Boost conversion module, and the other end of the second resistor is respectively connected to the other end of the ninth capacitor and the common source terminal of the first full-bridge circuit in the CLLLC conversion module.

12. The bidirectional resonant converter according to claim 8, characterized in that: The pre-charging circuit includes at least one tenth capacitor connected in parallel, at least one seventeenth control switch connected in parallel, and a third resistor, Among them, one end of the tenth capacitor is respectively connected to the common drain terminal and the positive electrode of the battery corresponding to the second full-bridge circuit and the third full-bridge circuit of the CLLLC conversion module, the other end of the tenth capacitor is connected to the drain of the seventeenth control switch, the source of the seventeenth control switch is respectively connected to one end of the third resistor and the common source terminal corresponding to the second full-bridge circuit and the third full-bridge circuit of the CLLLC conversion module, and the other end of the third resistor is connected to the negative electrode of the battery.

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