LLC resonant conversion circuit and power supply circuit

Abstract

The utility model provides an LLC resonant conversion circuit and a power supply circuit, and relates to the technical field of power supply circuits. The LLC resonant conversion circuit comprises an input power conversion circuit, a voltage detection circuit, a voltage conversion circuit, an output power conversion circuit and a clamping circuit. The first side of the clamping circuit is electrically connected with the second side of the output power conversion circuit, and the clamping side of the clamping circuit is electrically connected with the two ends of the voltage detection circuit. When a load is short-circuited or over-current occurs, the clamping circuit can clamp the current at the voltage detection circuit according to the set direct current output by the output power conversion circuit, so that the purpose of limiting the current of the LLC resonant conversion circuit is achieved, the problem that the LLC resonant conversion circuit is damaged due to the impact of large current is solved, and the service life of the LLC resonant conversion circuit is prolonged. And the reliability and the safety of the LLC resonant conversion circuit are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply circuits, and more specifically, to an LLC resonant conversion circuit and a power supply circuit. Background Art

[0002] With the development of technology, automobiles are no longer limited to fuel vehicles, and many new energy vehicles have emerged, such as electric vehicles currently on the market. Among them, electric vehicles have many advantages in terms of environmental protection and energy conservation. An electric vehicle refers to a vehicle powered by an on-vehicle power supply and driven by an electric motor to drive the wheels, indicating the importance of the on-vehicle power supply among the components of an electric vehicle.

[0003] Currently, LLC resonant conversion circuits are widely used in on-vehicle power supplies. The LLC resonant conversion circuit can achieve soft-switching zero-voltage turn-on, thereby optimizing the efficiency of the entire on-vehicle power supply. However, when the load electrically connected to the LLC resonant conversion circuit experiences a short circuit or overcurrent situation, the impact of a large current will cause damage to the LLC resonant conversion circuit, which is also one of the current technical problems that need to be urgently solved. Summary of the Utility Model

[0004] In view of this, the utility model provides an LLC resonant conversion circuit and a power supply circuit, effectively solving the technical problems existing in the prior art. When a short circuit or overcurrent problem occurs in the load, the current at the voltage detection circuit is clamped by the clamping circuit to achieve the purpose of current limiting, and the problem of damage to the LLC resonant conversion circuit caused by the impact of a large current is improved.

[0005] To achieve the above object, the technical solution provided by the utility model is as follows:

[0006] An LLC resonant conversion circuit includes: an input power conversion circuit, a voltage detection circuit, a voltage conversion circuit, an output power conversion circuit, and a clamping circuit;

[0007] The first side of the input power conversion circuit is electrically connected to a DC power supply, the second side of the input power conversion circuit forms a primary side loop with the primary side of the voltage conversion circuit, and the voltage detection circuit is electrically connected in the primary side loop;

[0008] The secondary side of the voltage conversion circuit is electrically connected to the first side of the output power conversion circuit, and the second side of the output power conversion circuit is electrically connected to a load to output a set DC power;

[0009] Moreover, the first side of the clamping circuit is electrically connected to the second side of the output power conversion circuit, and the clamping side of the clamping circuit is electrically connected to both ends of the voltage detection circuit.

[0010] Optionally, the LLC resonant conversion circuit includes a first resonant inductor, a second resonant inductor, and a resonant capacitor, and the first resonant inductor, the second resonant inductor, and the resonant capacitor are all electrically connected to the primary circuit;

[0011] Wherein, the voltage detection circuit includes a detection capacitor, and the detection capacitor and the resonant capacitor are the same capacitor;

[0012] And / or, the voltage conversion circuit includes a transformer, and the primary side of the transformer is the same inductor as the first resonant inductor or the second resonant inductor.

[0013] Optionally, the clamping circuit includes: a clamping voltage conversion circuit and a clamping power conversion circuit;

[0014] One end of the primary side of the clamping voltage conversion circuit is electrically connected to one end of the voltage detection circuit, and the other end of the primary side of the clamping voltage conversion circuit is electrically connected to the other end of the voltage detection circuit. The secondary side of the clamping voltage conversion circuit is electrically connected to the second side of the clamping power conversion circuit, and the first side of the clamping power conversion circuit is electrically connected to the second side of the output power conversion circuit.

[0015] Optionally, the clamping power conversion circuit includes a full-bridge power conversion circuit, and wherein, the clamping power conversion circuit includes:

[0016] A first switching device, a second switching device, a third switching device, and a fourth switching device. The first ends of the first switching device and the second switching device are both electrically connected to the positive pole of the second side of the output power conversion circuit. The second end of the first switching device and the first end of the third switching device are both electrically connected to one end of the secondary side of the clamping voltage conversion circuit. The second end of the second switching device and the first end of the fourth switching device are both electrically connected to the other end of the secondary side of the clamping voltage conversion circuit. The second ends of the third switching device and the fourth switching device are both electrically connected to the negative pole of the second side of the output power conversion circuit.

[0017] Optionally, the LLC resonant conversion circuit further includes: a first voltage stabilizing capacitor connected in parallel with the first side of the clamping power conversion circuit.

[0018] Optionally, the input power conversion circuit includes a full-bridge power conversion circuit, and wherein, the input power conversion circuit includes:

[0019] A fifth switching device, a sixth switching device, a seventh switching device, and an eighth switching device. A first end of the fifth switching device and a first end of the sixth switching device are both electrically connected to the positive electrode of a DC power supply. A second end of the fifth switching device and a first end of the seventh switching device are both electrically connected to one end of the primary side of the voltage conversion circuit. A second end of the sixth switching device and a first end of the eighth switching device are both electrically connected to the other end of the primary side of the voltage conversion circuit. A second end of the seventh switching device and a second end of the eighth switching device are both electrically connected to the negative electrode of the DC power supply.

[0020] Optionally, one resonant inductor in the LLC resonant conversion circuit is electrically connected in a connection line between the second end of the fifth switching device and the first end of the seventh switching device and the voltage conversion circuit;

[0021] And / or, the voltage detection circuit is electrically connected in a connection line between the second end of the sixth switching device and the first end of the eighth switching device and the voltage conversion circuit.

[0022] Optionally, the output power conversion circuit includes a full-bridge power conversion circuit. Among them, the output power conversion circuit includes:

[0023] A ninth switching device, a tenth switching device, an eleventh switching device, and a twelfth switching device. A first end of the ninth switching device and a first end of the tenth switching device are both electrically connected to the positive electrode of the load. A second end of the ninth switching device and a first end of the eleventh switching device are both electrically connected to one end of the secondary side of the voltage conversion circuit. A second end of the tenth switching device and a first end of the twelfth switching device are both electrically connected to the other end of the secondary side of the voltage conversion circuit. A second end of the eleventh switching device and a second end of the twelfth switching device are both electrically connected to the negative electrode of the load.

[0024] Optionally, the LLC resonant conversion circuit further includes: a second voltage stabilizing capacitor connected in parallel to the second side of the output power conversion circuit.

[0025] Based on the same inventive concept, the present utility model further provides a power supply circuit, and the power supply circuit includes the above-mentioned LLC resonant conversion circuit.

[0026] Optionally, the power supply circuit includes a vehicle-mounted power supply circuit.

[0027] Compared with the prior art, the technical solution provided by the present utility model has at least the following advantages:

[0028] The present utility model provides an LLC resonant conversion circuit and a power supply circuit, comprising: an input power conversion circuit, a voltage detection circuit, a voltage conversion circuit, an output power conversion circuit, and a clamping circuit; a first side of the input power conversion circuit is electrically connected to a DC power supply, a second side of the input power conversion circuit and a primary side of the voltage conversion circuit form a primary side loop, and the voltage detection circuit is electrically connected in the primary side loop; a secondary side of the voltage conversion circuit is electrically connected to a first side of the output power conversion circuit, a second side of the output power conversion circuit is electrically connected to a load to output a set DC power; and, a first side of the clamping circuit is electrically connected to the second side of the output power conversion circuit, and a clamping side of the clamping circuit is electrically connected to both ends of the voltage detection circuit.

[0029] As can be seen from the above, in the technical solution provided by the present utility model, when a short circuit or overcurrent problem occurs in the load, the clamping circuit can clamp the current at the voltage detection circuit according to the set DC power output by the output power conversion circuit, achieving the purpose of limiting the current of the LLC resonant conversion circuit, improving the problem that the LLC resonant conversion circuit is damaged by the impact of large current, and enhancing the reliability and safety of the LLC resonant conversion circuit. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present utility model, and for those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0031] Figure 1 It is a circuit diagram of an LLC resonant conversion circuit provided by an embodiment of the present utility model;

[0032] Figure 2 It is a circuit diagram of another LLC resonant conversion circuit provided by an embodiment of the present utility model;

[0033] Figure 3 It is a circuit diagram of yet another LLC resonant conversion circuit provided by an embodiment of the present utility model;

[0034] Figure 4 It is a circuit diagram of yet another LLC resonant conversion circuit provided by an embodiment of the present utility model;

[0035] Figure 5 It is a circuit diagram of yet another LLC resonant conversion circuit provided by an embodiment of the present utility model;

[0036] Figure 6The circuit diagram of a power supply circuit provided by an embodiment of the present utility model. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0038] As described in the background art, LLC resonant conversion circuits are widely used in vehicle power supplies. LLC resonant conversion circuits can achieve soft-switching zero-voltage turn-on, thereby optimizing the efficiency of the entire vehicle power supply. However, when the load electrically connected to the LLC resonant conversion circuit is short-circuited or overcurrent occurs, the impact of large current will cause damage to the LLC resonant conversion circuit, which is also one of the technical problems that need to be solved urgently at present.

[0039] Based on this, the embodiments of the present utility model provide an LLC resonant conversion circuit and a power supply circuit, which effectively solve the technical problems existing in the prior art. When a short-circuit or overcurrent problem occurs in the load, the current at the voltage detection circuit is clamped by the clamping circuit to achieve the purpose of current limiting, and the problem of damage to the LLC resonant conversion circuit caused by the impact of large current is improved.

[0040] To achieve the above object, the technical solutions provided by the embodiments of the present utility model are as follows, and will be specifically described in combination with Figures 1 to 6 a detailed description of the technical solutions provided by the embodiments of the present utility model.

[0041] Refer to Figure 1 As shown, it is the circuit diagram of an LLC resonant conversion circuit provided by an embodiment of the present utility model. Among them, the LLC resonant conversion circuit provided by the embodiment of the present utility model includes: an input power conversion circuit 100, a voltage detection circuit, a voltage conversion circuit TS1, an output power conversion circuit 200, and a clamping circuit 300.

[0042] The first side of the input power conversion circuit 100 is electrically connected to a DC power supply (i.e., the positive electrode Ui+ and the negative electrode Ui- of the DC power supply), the second side of the input power conversion circuit 100 forms a primary loop with the primary side of the voltage conversion circuit TS1, and the voltage detection circuit C1 is electrically connected in the primary loop. The secondary side of the voltage conversion circuit TS1 is electrically connected to the first side of the output power conversion circuit 200, and the second side of the output power conversion circuit 200 is electrically connected to the load 400 to output a set DC power (i.e., the set DC power output from the positive electrode U0+ and the negative electrode U0- on the second side of the output power conversion circuit 200); and, the first side of the clamping circuit 300 is electrically connected to the second side of the output power conversion circuit 200, and the clamping side of the clamping circuit 300 is electrically connected to both ends of the voltage detection circuit C1.

[0043] It can be understood that for the technical solution provided in the embodiment of the present invention, the input power conversion circuit is used to convert the DC power output by the DC power supply into a set AC power. Then, after the set AC power is transformed by the voltage conversion circuit, it is converted into a set DC power by the output power conversion circuit and output to the load. When a short circuit or overcurrent problem occurs in the load, the clamping circuit can clamp the current at the voltage detection circuit according to the set DC power output by the output power conversion circuit, achieving the purpose of limiting the current of the LLC resonant conversion circuit, improving the problem that the large current impact damages the LLC resonant conversion circuit, and improving the reliability and safety of the LLC resonant conversion circuit.

[0044] It should be noted that the circuit provided in the embodiment of the present invention is an LLC resonant conversion circuit, where LLC is a circuit including two resonant inductors and a resonant capacitor, that is, the LLC resonant conversion circuit includes a first resonant inductor, a second resonant inductor and a resonant capacitor, and the first resonant inductor, the second resonant inductor and the resonant capacitor are all electrically connected in the primary loop; wherein, the voltage detection circuit provided in the embodiment of the present invention may include a detection capacitor, and the detection capacitor and the resonant capacitor are the same capacitor; and / or, the voltage conversion circuit includes a transformer, and the primary side of the transformer and the first resonant inductor or the second resonant inductor are the same inductor. That is to say, the voltage detection circuit provided in the embodiment of the present invention includes a detection capacitor, and the detection capacitor and the resonant capacitor may be the same capacitor; or, the voltage conversion circuit includes a transformer, and the primary side of the transformer and the first resonant inductor or the second resonant capacitor are the same inductor; or, the voltage detection circuit includes a detection capacitor, and the detection capacitor and the resonant capacitor may be the same capacitor, and at the same time, the voltage conversion circuit includes a transformer, and the primary side of the two transformers and the first resonant inductor or the second resonant capacitor are the same inductor.

[0045] Specifically, such as Figure 1As shown, the LLC resonant conversion circuit provided by the embodiment of the present utility model includes a first resonant inductor L1, a second resonant inductor, and a resonant capacitor, where the resonant capacitor and the detection capacitor are the same capacitor C1, and the primary side of the voltage conversion circuit TS1 can be equivalent to the second resonant inductor to form an LLC circuit. Or, as Figure 2 shown in the LLC resonant conversion circuit, it includes a first resonant inductor L1, a second resonant inductor L2, and a resonant capacitor. Among them, the resonant capacitor and the detection capacitor are the same capacitor C1, and the second resonant inductor L2 is separately provided. The second resonant inductor L2 is connected in parallel with the primary side of the voltage conversion circuit TS1, and an LLC circuit is formed by the resonant inductor L1, the resonant inductor L2, and the resonant capacitor C1. The present utility model does not make specific limitations on this.

[0046] It should be noted that the description of the following embodiments of the present utility model is made by taking the voltage detection circuit including a detection capacitor, and the detection capacitor and the resonant capacitor being the same capacitor, and the voltage conversion circuit including a transformer, and the primary side of the transformer and the second resonant inductor being the same inductor as examples.

[0047] Refer to Figure 3 shown, which is the circuit diagram of another LLC resonant conversion circuit provided by the embodiment of the present utility model. Among them, the clamping circuit 300 provided by the embodiment of the present utility model includes: a clamping voltage conversion circuit TS2 and a clamping power conversion circuit 310. Among them, the clamping voltage conversion circuit TS2 may include a clamping transformer.

[0048] One end of the primary side of the clamping voltage conversion circuit TS2 is electrically connected to one end of the voltage detection circuit, and the other end of the primary side of the clamping voltage conversion circuit TS2 is electrically connected to the other end of the voltage detection circuit. The secondary side of the clamping voltage conversion circuit TS2 is electrically connected to the second side of the clamping power conversion circuit 310, and the first side of the clamping power conversion circuit 310 is electrically connected to the second side of the output power conversion circuit 200.

[0049] It can be understood that in the technical solution provided by the embodiment of the present invention, the clamping power conversion circuit is electrically connected to the second side of the output power conversion circuit, that is, the first side of the clamping power conversion circuit is connected to the set direct current output by the output power conversion circuit. The resonant capacitor is electrically connected to the primary side of the clamping transformer. That is to say, when clamping the current on the resonant capacitor, it is achieved by clamping the voltage on the resonant capacitor, and then the purpose of clamping the current on the resonant capacitor is achieved. It should be noted that the embodiment of the present invention does not specifically limit the value after clamping the voltage on the resonant capacitor, that is, the value range after clamping the current on the resonant capacitor is not specifically limited, and specific parameters such as the coil turn ratio of the primary side and the secondary side of the clamping transformer need to be specifically designed according to actual applications. Optionally, the value after clamping the voltage on the resonant capacitor can be set to a relatively small value, such as the clamping voltage after clamping the voltage on the resonant capacitor is less than the output voltage of the set direct current.

[0050] Specifically, in the normal situation where the load is not short-circuited or over-current, the voltage on the secondary side of the clamping transformer is greater than the voltage on the primary side of the clamping transformer. Furthermore, when the load is not short-circuited or over-current, the LLC resonant conversion circuit works normally, the voltage on the resonant capacitor is relatively low, and the voltage on the secondary side of the clamping transformer is higher than its primary side voltage, so that the current clamping circuit does not perform a protection action. When the load is short-circuited or over-current, the LLC resonant conversion circuit does not work normally, the current on the resonant capacitor will increase accordingly, causing the voltage on the resonant capacitor to increase sharply, that is, causing the voltage on the primary side of the clamping transformer to increase, and then causing the voltage on the secondary side of the clamping transformer to increase; at this time, the current clamping circuit starts to perform a protection action. Among them, since the secondary side of the clamping transformer is electrically connected to the clamping power conversion circuit, the voltage on the secondary side of the clamping transformer comes from the output voltage of the set direct current output by the output power conversion circuit. In this way, the voltage on the resonant capacitor will be clamped by this output voltage, and then the current on the resonant capacitor will also be clamped, ultimately achieving the purpose of current limiting.

[0051] In an embodiment of the present invention, the power conversion circuit provided by the embodiment of the present invention may include but is not limited to a full-bridge power conversion circuit, and the present invention does not specifically limit this. Refer to Figure 4As shown, it is a circuit diagram of another LLC resonant conversion circuit provided by an embodiment of the present invention. Among them, the clamping power conversion circuit 310 provided by the embodiment of the present invention includes a full-bridge power conversion circuit. Among them, the clamping power conversion circuit includes: a first switching device K1, a second switching device K2, a third switching device K3, and a fourth switching device K4. The first ends of the first switching device K1 and the second switching device K2 are both electrically connected to the positive pole U0+ of the second side of the output power conversion circuit 200. The second end of the first switching device K1 and the first end of the third switching device K3 are both electrically connected to one end of the secondary side of the clamping voltage conversion circuit TS2. The second end of the second switching device K2 and the first end of the fourth switching device K4 are both electrically connected to the other end of the secondary side of the clamping voltage conversion circuit TS2. The second ends of the third switching device K3 and the fourth switching device K4 are both electrically connected to the negative pole U0- of the second side of the output power conversion circuit 200. Further, the LLC resonant conversion circuit provided by the embodiment of the present invention further includes: a first voltage stabilizing capacitor CR1 connected in parallel to the first side of the clamping power conversion circuit 310. By using the first voltage stabilizing capacitor CR1 to stabilize the voltage on the first side of the clamping power conversion circuit 310, the performance of the LLC resonant conversion circuit is improved.

[0052] Continue to refer to Figure 4 As shown, the input power conversion circuit 100 provided by the embodiment of the present invention includes a full-bridge power conversion circuit. Among them, the input power conversion circuit 100 includes: a fifth switching device K5, a sixth switching device K6, a seventh switching device K7, and an eighth switching device K8. The first ends of the fifth switching device K5 and the sixth switching device K6 are both electrically connected to the positive pole Ui+ of the DC power supply. The second end of the fifth switching device K5 and the first end of the seventh switching device K7 are both electrically connected to one end of the primary side of the voltage conversion circuit TS1. The second end of the sixth switching device K6 and the first end of the eighth switching device K8 are both electrically connected to the other end of the primary side of the voltage conversion circuit TS2. The second ends of the seventh switching device K7 and the eighth switching device K8 are both electrically connected to the negative pole Ui- of the DC power supply.

[0053] In the embodiment of the present utility model, the resonant inductor L1 and the voltage detection circuit C1 are electrically connected in the primary loop formed by the input power conversion circuit 100 and the primary side of the voltage conversion circuit TS1. Optionally, one of the resonant inductors in the LLC resonant conversion circuit provided by the embodiment of the present utility model, such as the first resonant inductor L1, is electrically connected in the connection line between the second end of the fifth switching device K5 and the first end of the seventh switching device K7 and the voltage conversion circuit TS1; and / or, the voltage detection circuit is electrically connected in the connection line between the second end of the sixth switching device K6 and the first end of the eighth switching device K8 and the voltage conversion circuit TS1. The present utility model does not make specific limitations on this.

[0054] Continuing as Figure 4 As shown, the output power conversion circuit 200 provided by the embodiment of the present utility model includes a full-bridge power conversion circuit. Among them, the output power conversion circuit 200 includes: a ninth switching device K9, a tenth switching device K10, an eleventh switching device K11, and a twelfth switching device K12. The first ends of the ninth switching device K9 and the tenth switching device K10 are both electrically connected to the positive pole of the load 400. The second end of the ninth switching device K9 and the first end of the eleventh switching device K11 are both electrically connected to one end of the secondary side of the voltage conversion circuit TS1. The second end of the tenth switching device K10 and the first end of the twelfth switching device K12 are both electrically connected to the other end of the secondary side of the voltage conversion circuit TS1. The second ends of the eleventh switching device K11 and the twelfth switching device K12 are both electrically connected to the negative pole of the load 400.

[0055] Furthermore, the LLC resonant conversion circuit provided by the embodiment of the present utility model further includes: a second voltage stabilizing capacitor CR2 connected in parallel to the second side of the output power conversion circuit 200. By using the second voltage stabilizing capacitor CR2 to stabilize the voltage on the second side of the output power conversion circuit 200, the performance of the LLC resonant conversion circuit is improved. Optionally, the first voltage stabilizing capacitor CR1 and the second voltage stabilizing capacitor CR2 provided by the embodiment of the present utility model can also be reused as the same voltage stabilizing capacitor, specifically as Figure 5 shown, thereby reducing the number of components in the LLC resonant conversion circuit and lowering the device cost and volume.

[0056] In any of the above embodiments of the present utility model, in the power conversion circuit of the LLC resonant conversion circuit provided by the embodiments of the present utility model, there is no specific limitation on the type of the switching devices (such as the first to the twelfth switching devices) included therein, which may be MOS transistors (Metal-Oxide-Semiconductor Field-Effect Transistors), IGBTs (Insulate-Gate Bipolar Transistors), etc., and specific designs need to be made according to actual applications. In addition, the present utility model does not specifically limit the switching frequency and the like of the switching devices in the above power conversion circuit.

[0057] Based on the same inventive concept, the embodiments of the present utility model further provide a power supply circuit, and the power supply circuit includes the LLC resonant conversion circuit provided by any of the above embodiments.

[0058] Optionally, the power supply circuit provided by the embodiments of the present utility model includes a vehicle-mounted power supply circuit. For specific reference Figure 6 As shown, it is a circuit diagram of a power supply circuit provided by the embodiments of the present utility model. Among them, the power supply circuit includes an OBC (onboard charger) circuit. The OBC circuit includes a PFC (Power Factor Correction) circuit 10 and an LLC resonant conversion circuit 20, and the LLC resonant conversion circuit 20 is the LLC resonant conversion circuit provided by any of the above embodiments. Among them, the PFC is used to convert a charging power supply 30 (the charging power supply 30 may be an AC charging power supply) into a DC power supply. The LLC resonant conversion circuit 20 is electrically connected to the DC power supply (the positive electrode Ui+ and the negative electrode Ui- of the DC power supply), and converts the output of the DC power supply into a set DC power and transmits it to a load 400 (wherein, the load 400 provided by the embodiments of the present utility model may be a high-voltage power battery).

[0059] It should be noted that the power supply circuit provided by the embodiments of the present utility model can also be applied to other types of circuits, and is not limited to the above vehicle-mounted power supply circuit, and the present utility model does not make specific limitations thereto.

[0060] An embodiment of the present utility model provides an LLC resonant conversion circuit and a power supply circuit, including: an input power conversion circuit, a voltage detection circuit, a voltage conversion circuit, an output power conversion circuit, and a clamping circuit; a first side of the input power conversion circuit is electrically connected to a DC power supply, a second side of the input power conversion circuit and a primary side of the voltage conversion circuit form a primary side loop, and the voltage detection circuit is electrically connected in the primary side loop; a secondary side of the voltage conversion circuit is electrically connected to a first side of the output power conversion circuit, a second side of the output power conversion circuit is electrically connected to a load to output a set DC power; and, a first side of the clamping circuit is electrically connected to the second side of the output power conversion circuit, and a clamping side of the clamping circuit is electrically connected to both ends of the voltage detection circuit.

[0061] As can be seen from the above, in the technical solution provided by the embodiment of the present utility model, when a short circuit or overcurrent problem occurs in the load, the clamping circuit can clamp the current at the voltage detection circuit according to the set DC power output by the output power conversion circuit, achieving the purpose of limiting the current of the LLC resonant conversion circuit, improving the problem that the LLC resonant conversion circuit is damaged by the impact of large current, and improving the reliability and safety of the LLC resonant conversion circuit.

[0062] In the description of the present utility model, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present utility model.

[0063] In addition, if terms such as "first" and "second" are only used for descriptive purposes, they cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0064] In the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "coupling", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection, an electrical connection, or communication with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0065] In the present utility model, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature is at a higher level than the second feature in terms of horizontal height. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature is at a lower level than the second feature in terms of horizontal height.

[0066] In the present utility model, terms such as "an embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0067] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present utility model.

Claims

1. An LLC resonant conversion circuit, characterized in that Including: An input power conversion circuit, a voltage detection circuit, a voltage conversion circuit, an output power conversion circuit, and a clamping circuit; A first side of the input power conversion circuit is electrically connected to a DC power supply, a second side of the input power conversion circuit and a primary side of the voltage conversion circuit form a primary side loop, and the voltage detection circuit is electrically connected in the primary side loop; A secondary side of the voltage conversion circuit is electrically connected to a first side of the output power conversion circuit, and a second side of the output power conversion circuit is electrically connected to a load to output a set DC power; Moreover, a first side of the clamping circuit is electrically connected to a second side of the output power conversion circuit, and a clamping side of the clamping circuit is electrically connected to both ends of the voltage detection circuit.

2. The LLC resonant conversion circuit according to claim 1, wherein The LLC resonant conversion circuit includes a first resonant inductor, a second resonant inductor, and a resonant capacitor, and the first resonant inductor, the second resonant inductor, and the resonant capacitor are all electrically connected in the primary side loop; Wherein, the voltage detection circuit includes a detection capacitor, and the detection capacitor and the resonant capacitor are the same capacitor; And / or, the voltage conversion circuit includes a transformer, and a primary side of the transformer and the first resonant inductor or the second resonant inductor are the same inductor.

3. The LLC resonant conversion circuit according to claim 1, wherein The clamping circuit includes: a clamping voltage conversion circuit and a clamping power conversion circuit; One end of a primary side of the clamping voltage conversion circuit is electrically connected to one end of the voltage detection circuit, and the other end of the primary side of the clamping voltage conversion circuit is electrically connected to the other end of the voltage detection circuit. A secondary side of the clamping voltage conversion circuit is electrically connected to a second side of the clamping power conversion circuit, and a first side of the clamping power conversion circuit is electrically connected to a second side of the output power conversion circuit.

4. The LLC resonant conversion circuit according to claim 3, characterized in that, The clamping power conversion circuit includes a full-bridge power conversion circuit. Among them, the clamping power conversion circuit includes: A first switching device, a second switching device, a third switching device, and a fourth switching device. A first end of the first switching device and a first end of the second switching device are both electrically connected to a positive electrode of a second side of the output power conversion circuit. A second end of the first switching device and a first end of the third switching device are both electrically connected to one end of a secondary side of the clamping voltage conversion circuit. A second end of the second switching device and a first end of the fourth switching device are both electrically connected to the other end of the secondary side of the clamping voltage conversion circuit. A second end of the third switching device and a second end of the fourth switching device are both electrically connected to a negative electrode of a second side of the output power conversion circuit.

5. The LLC resonant conversion circuit according to claim 3, wherein, The LLC resonant conversion circuit further includes: a first voltage stabilizing capacitor connected in parallel to a first side of the clamping power conversion circuit.

6. The LLC resonant conversion circuit according to claim 1, wherein, The input power conversion circuit includes a full-bridge power conversion circuit. Among them, the input power conversion circuit includes: A fifth switching device, a sixth switching device, a seventh switching device, and an eighth switching device. A first end of the fifth switching device and a first end of the sixth switching device are both electrically connected to the positive electrode of a DC power supply. A second end of the fifth switching device and a first end of the seventh switching device are both electrically connected to one end of the primary side of the voltage conversion circuit. A second end of the sixth switching device and a first end of the eighth switching device are both electrically connected to the other end of the primary side of the voltage conversion circuit. A second end of the seventh switching device and a second end of the eighth switching device are both electrically connected to the negative electrode of the DC power supply.

7. The LLC resonant conversion circuit according to claim 6, wherein One resonant inductor in the LLC resonant conversion circuit is electrically connected in a connection line between the second end of the fifth switching device and the first end of the seventh switching device and the voltage conversion circuit; And / or, the voltage detection circuit is electrically connected in a connection line between the second end of the sixth switching device and the first end of the eighth switching device and the voltage conversion circuit.

8. The LLC resonant conversion circuit according to claim 1, wherein The output power conversion circuit includes a full-bridge power conversion circuit. Among them, the output power conversion circuit includes: A ninth switching device, a tenth switching device, an eleventh switching device, and a twelfth switching device. A first end of the ninth switching device and a first end of the tenth switching device are both electrically connected to the positive electrode of the load. A second end of the ninth switching device and a first end of the eleventh switching device are both electrically connected to one end of the secondary side of the voltage conversion circuit. A second end of the tenth switching device and a first end of the twelfth switching device are both electrically connected to the other end of the secondary side of the voltage conversion circuit. A second end of the eleventh switching device and a second end of the twelfth switching device are both electrically connected to the negative electrode of the load.

9. The LLC resonant conversion circuit according to claim 8, wherein, The LLC resonant conversion circuit further includes: a second voltage stabilizing capacitor connected in parallel to the second side of the output power conversion circuit.

10. A power supply circuit, characterized in that, The power supply circuit includes the LLC resonant conversion circuit according to any one of claims 1-9.

11. The power supply circuit according to claim 10, wherein, The power supply circuit includes a vehicle-mounted power supply circuit.

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