Resonant converter circuit and charging device, electronic device

Abstract

The specification provides a resonant converter circuit, a charging device and an electronic device, comprising a primary circuit located at the primary side of a transformer and a secondary circuit located at the secondary side of the transformer, the primary circuit comprising a multi-phase parallel resonant conversion circuit, and the secondary circuit comprising a multi-phase full-bridge rectifier circuit, a first bridge arm of an i-th phase rectifier circuit comprising a first transistor, a second transistor and a first current-sharing capacitor, a second bridge arm of the i-th phase rectifier circuit comprising a third transistor, a fourth transistor and a second current-sharing capacitor, one end of a first bridge arm of an i+1-th phase rectifier circuit being connected to an output-side power supply and the other end being connected between the first transistor and the first current-sharing capacitor, one end of a second bridge arm of the i+1-th phase rectifier circuit being connected to the output-side power supply and the other end being connected between the third transistor and the second current-sharing capacitor, the multi-phase parallel circuit being capable of achieving a high-power power supply output, and the multi-phase rectifier circuit being capable of achieving current self-balancing by using a charge balance principle, reducing current stress, and reducing cost and volume.

Description

Technical Field

[0001] This specification relates to the field of electronic circuit technology, specifically to a resonant converter circuit and a charging device and electronic equipment. Background Technology

[0002] With the development of charging technology, charging adapters are gradually moving towards higher power and smaller size. LLC resonant converters can achieve electrical isolation between input and output, and have advantages such as small transformer size, easy soft switching, high efficiency and power density, so they are widely used.

[0003] LLC typically uses high-frequency PFM (Pulse Frequency Modulation) control. Due to the limited switching frequency range, the voltage gain range of LLC within the switching frequency range is narrow, which cannot meet the application scenarios that require a wide voltage range. Utility Model Content

[0004] To improve the voltage gain range of LLC circuits and achieve current self-balancing in multiphase LLC circuits, this specification provides a resonant converter circuit, a charging device, and an electronic device.

[0005] In a first aspect, this specification provides a resonant converter circuit, including a primary circuit located on the primary side of a transformer and a secondary circuit located on the secondary side of the transformer. The primary circuit includes an N-phase parallel resonant converter circuit, and the secondary circuit includes an N-phase rectifier circuit, where N ≥ 2. The rectifier circuit is a full-bridge rectifier circuit, and for adjacent i-th and (i+1)-th phase rectifier circuits in the N-phase rectifier circuit, i ≥ 1. The first bridge arm of the i-th phase rectifier circuit includes a first transistor, a second transistor, and a first current sharing capacitor; the second bridge arm of the i-th phase rectifier circuit includes a third transistor, a fourth transistor, and a second current sharing capacitor. One end of the first bridge arm of the (i+1)th phase rectifier circuit is connected to the output power supply, and the other end is connected between the first transistor and the first current sharing capacitor. One end of the second bridge arm of the (i+1)th phase rectifier circuit is connected to the output power supply, and the other end is connected between the third transistor and the second current sharing capacitor.

[0006] In some implementations, the output of the first bridge arm of each phase of the rectifier circuit is connected to the secondary side of the transformer via a rectifier capacitor, the output of the first bridge arm is located between the first current sharing capacitor and the second transistor, and the output of the second bridge arm of the rectifier circuit is located between the second current sharing capacitor and the fourth transistor.

[0007] In some implementations, with N=2, the two-phase rectifier circuit operates alternately with a 180-degree phase difference and a duty cycle of 0.5.

[0008] In some implementations, in each phase rectifier circuit, the fourth transistor of the second bridge arm is a MOSFET, and the other transistors are diodes. The MOSFET includes a parasitic diode, wherein the parasitic diode and the other diodes have the same current conduction direction.

[0009] In some implementations, the resonant converter circuit further includes a control circuit for controlling the switching on and off of the MOS transistor.

[0010] In some implementations, when i=1, the first and second bridge arms of the i-th phase rectifier circuit are connected in parallel, with one end of the parallel connection connected to one of the poles of the output power supply and the other end connected to the other pole of the output power supply.

[0011] In some embodiments, the primary circuit includes a full-bridge input circuit and the resonant converter circuit, with the bridge arm output of the full-bridge input circuit connected to the resonant converter circuit, which is located on the primary side of the transformer.

[0012] In some implementations, a filter capacitor is connected in parallel between the full-bridge input circuit and the input-side power supply.

[0013] Secondly, embodiments of this specification provide a charging device including the resonant converter circuit of any of the above embodiments.

[0014] Thirdly, embodiments of this specification provide an electronic device, including a device body and a charging device, wherein the charging device is used to supply power to the device body, and the charging device is the charging device described in any of the above embodiments.

[0015] The resonant converter circuit described in this specification includes a multiphase resonant converter circuit. By connecting multiphase LLC circuits in parallel, high-power power output can be achieved, and a wide voltage gain range can be realized. Furthermore, by utilizing the charge balance principle of capacitors and through an improved rectifier circuit structure, current self-balancing of the multiphase rectifier circuit is achieved, reducing current stress. Moreover, no complex current sharing control circuit is required, which reduces circuit cost and transformer size, and is conducive to the miniaturization and high power of charging equipment. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments or technical solutions in the prior art of this specification, the accompanying drawings used in the description of the specific embodiments or prior art will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this specification. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the LLC circuit in related technologies.

[0018] Figure 2 This is a circuit diagram combining LLC and BUCK circuits in related technologies.

[0019] Figure 3 This is a schematic diagram of a two-phase LLC circuit in related technologies.

[0020] Figure 4 This is a circuit diagram of the resonant converter circuit in some embodiments of this specification.

[0021] Figure 5a and Figure 5b This is a schematic diagram of the working principle of the resonant converter circuit in this manual.

[0022] Figure 6 This is the voltage gain curve of the resonant converter circuit in this manual. Detailed Implementation

[0023] The technical solutions of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, not all of them. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this specification. Furthermore, the technical features involved in the different embodiments of this specification described below can be combined with each other as long as they do not conflict with each other.

[0024] With the development of charging technology, power adapters are gradually trending towards higher power and smaller size. To achieve this, it is necessary to increase the power density of chargers through higher frequency and higher efficiency. LLC resonant converters can achieve electrical isolation between input and output, and have advantages such as small transformer size, easy soft switching, high efficiency and high power density. Therefore, they are widely used in high-power and miniaturized charging scenarios, such as laptop power adapters and new energy vehicle charging piles.

[0025] However, LLC is limited by its circuit topology and PFM (Pulse Frequency Modulation) frequency control, resulting in a limited switching frequency range. Therefore, LLC has a narrow voltage gain range within the switching frequency range, which cannot meet the application scenarios that require a wide voltage range.

[0026] Figure 1 This diagram illustrates a conventional single-phase LLC circuit topology. The LLC primarily consists of a primary circuit on the primary side, a transformer, and a secondary circuit on the secondary side. The primary circuit includes a full-bridge or half-bridge switching circuit and a resonant cavity, for example... Figure 1 The full-bridge switching circuit includes four switching transistors Q1 to Q4, and the resonant cavity includes a resonant inductor Lr, a resonant capacitor Cr, and a magnetizing inductor Lm. The secondary circuit is a full-bridge or half-bridge rectifier circuit, which is typically composed of transistors (such as transistors D1 and D2). The primary circuit is responsible for converting the input DC voltage Vin into high-frequency AC voltage. The transformer transfers energy from the primary side to the secondary side, and the rectifier circuit is responsible for converting the AC voltage output from the transformer into a stable DC voltage V0.

[0027] When the input voltage Vin or output load of the LLC resonant converter changes, the voltage gain (i.e., V0 / Vin) of the LLC needs to be adjusted by changing the switching frequency or duty cycle of the switching transistors Q1~Q4 to stabilize the output voltage V0. In this process, the voltage gain range of the LLC is limited by the switching frequency range. A single-phase LLC has a narrow voltage gain range within the switching frequency range, making it difficult to achieve a wide voltage gain through frequency conversion control, thus failing to meet the needs of applications requiring a wide voltage range.

[0028] Figure 2 A solution in the related art is shown, in which a BUCK circuit is connected to the output of the LLC circuit, and the high-frequency drive is achieved by using the PFM modulation control of the LLC, thereby reducing the size of the transformer and improving its efficiency. On the output side, the PWM (Pulse Width Modulation) modulation control of the BUCK circuit is used to achieve a wide range of voltage output.

[0029] exist Figure 2 While the proposed solution utilizes a BUCK circuit to achieve a relatively wide voltage range, the BUCK circuit itself incurs losses. These losses increase significantly, especially when the input-output voltage difference is large, leading to lower system efficiency. Furthermore, the BUCK circuit requires a filter inductor L. buck Filter capacitor C buck and freewheeling transistor D buckWhen transmitting large amounts of energy, these devices are relatively large, which is detrimental to the miniaturization of system circuits. Furthermore, LLC and BUCK circuits use different control methods, so achieving coordinated operation between the two stages places extremely high demands on the control circuit, leading to increased costs. Additionally, as power increases, the BUCK circuit, being a hard-switching circuit, experiences significant heat generation due to rectifier and inductor losses.

[0030] Figure 3 The topology of a two-phase LLC circuit is shown. In a multi-phase LLC circuit, high power output can be achieved by paralleling power supplies. However, for a multi-phase parallel LLC system, there is a situation where the current is concentrated in one phase circuit due to the differences in devices or controls between different power supplies. Therefore, current balancing of the multi-phase circuit is required.

[0031] exist Figure 3 In this design, the A-phase circuit and the B-phase circuit are connected in parallel. Each phase circuit requires separate PFM control to achieve current balance. Moreover, the control system of each phase requires an additional auxiliary control loop, which makes the control circuit very complex and increases losses, resulting in poor power efficiency.

[0032] Based on this, the embodiments of this specification provide a resonant converter circuit and a charging device having the resonant converter circuit, which aims to achieve a wide range of voltage output through multi-phase LLC parallel connection, and achieve current self-balancing through improved rectifier circuit structure, eliminating the need for complex current sharing control circuit, reducing circuit cost and transformer size, and facilitating the miniaturization and high power of the charging device.

[0033] In some implementations, the resonant converter LLC circuit provided in this specification includes a primary circuit located on the primary side of the transformer and a secondary circuit located on the secondary side of the transformer. The primary side of the transformer refers to the power input terminal, which is connected to the input power supply (Vin), and the secondary side of the transformer refers to the power output terminal, which is connected to the output power supply (Vout) or the load. The primary circuit refers to the input circuit, and the secondary circuit refers to the output circuit. The primary circuit receives energy from the input power supply and transfers it to the secondary circuit through the transformer. The primary circuit and the secondary circuit are electrically isolated by the transformer.

[0034] In the embodiments described in this specification, the primary circuit adopts a multi-phase parallel LLC circuit topology, that is, the primary circuit includes N (N≥2) phase parallel resonant converter circuits. Similarly, the secondary circuit also includes an N-phase rectifier circuit. The N-phase rectifier circuit and the N-phase resonant converter circuit are connected one-to-one through transformers.

[0035] Figure 4 The topology of the resonant converter circuit in some embodiments of this specification is shown. Figure 4 In the example, the resonant converter circuit adopts a two-phase LLC topology, that is, N is 2. The following section will discuss this further. Figure 4 The circuit structure and principle of the embodiments described in this specification are explained.

[0036] In some implementations, the primary circuit can employ an H-bridge input circuit, which includes two parallel bridge arms, each with two series-connected transistor switches. For example... Figure 4 In the example, the first arm of the full-bridge input circuit includes the power switch Q. AH and Q AL The second bridge arm includes the power switch Q. BH and Q BL .

[0037] Switching transistor Q AH One end is connected to the switching transistor Q BH One end is connected and connected to one pole of the input power supply Vin, and the switching transistor Q... AL One end is connected to the switching transistor Q BL One end of the transistor is connected to the input power supply Vin, and the other end is connected to the input power supply Vin. Switch Q AH The other end is connected to the switching transistor Q. AL The other end is connected as the output terminal A of the first bridge arm. Switch Q BH The other end is connected to the switching transistor Q. BL The other end is connected as the output terminal B of the second bridge arm.

[0038] The aforementioned switching transistors can be transistor switches, such as diodes, triodes, MOSFETs, etc., and this specification does not impose any restrictions on this.

[0039] exist Figure 4 In the example, output terminal A of the first bridge arm provides the input power for phase A circuit, and output terminal B of the second bridge arm provides the input power for phase B circuit. In the embodiments described below in this specification, the two phase circuits in the two-phase LLC circuit are described as phase A and phase B, respectively.

[0040] Continue to refer to Figure 4 As shown, on the primary circuit side, output terminal A is connected to the resonant converter circuit of phase A. The resonant converter circuit of phase A includes a resonant capacitor C. rA Resonant inductor L kgA and excitation inductance L mgA Similarly, the output terminal B is connected to the resonant converter circuit of phase B. The resonant converter circuit of phase B includes the resonant capacitor C. rB Resonant inductor L kgB and excitation inductance L mgBThe A-phase resonant converter circuit uses transformer T. rA Coupled with the A-phase rectifier circuit on the secondary side, the B-phase resonant converter circuit is connected to the transformer T. rB It is coupled to the B-phase rectifier circuit on the secondary side.

[0041] It is understandable that the above Figure 4 The example uses a two-phase circuit structure for illustration only. In other embodiments, the primary circuit may also include a resonant converter circuit with more phases, such as N taking values ​​of 3, 4, 5, etc. The multi-phase resonant converter circuit is described below. Figure 4 The example circuit topology can be connected in parallel.

[0042] In some implementations, a filter capacitor C is also provided on the primary circuit side. in The two bridge arms of the full-bridge input circuit and the filter capacitor C in Parallel connection, filter capacitor C in Used to filter the input power supply Vin, improving the stability of the power input.

[0043] On the secondary circuit side, corresponding to the primary circuit, the same number N rectifier circuits are provided, thus forming a one-to-one correspondence between the rectifier circuits and the resonant converter circuit to create a single-phase power supply. For example... Figure 4 In the example, the rectifier circuit includes a phase A rectifier circuit and a phase B rectifier circuit. The phase A rectifier circuit is connected to a transformer T. rA Coupled with the primary side A-phase resonant converter circuit, the B-phase rectifier circuit is connected to the transformer T. rB It is coupled with the primary side B-phase resonant converter circuit.

[0044] It is worth noting that in the embodiments described in this specification, the N-phase rectifier circuit does not adopt the traditional parallel circuit architecture. This is because, as mentioned above, the parallel rectifier circuit requires additional auxiliary control circuits for each phase circuit to achieve multi-phase current balance and avoid current concentration in one or a few phases, which would lead to current imbalance.

[0045] In the embodiments described in this specification, by improving the topology of the rectifier circuit on the output side, current self-balancing between adjacent two-phase rectifier circuits can be achieved, for example... Figure 4 In the example dual-phase LLC circuit, no additional control circuits are needed for the A-phase rectifier circuit and the B-phase rectifier circuit to achieve automatic current sharing between the two circuits. This will be explained in detail below.

[0046] First of all, it is understandable that Figure 4The example only shows the circuit architecture of a two-phase LLC. In other embodiments, the resonant converter circuit may include a circuit architecture with more phases. In the following embodiments, the structure and principle of the rectifier circuit will be explained using any two adjacent phases (phase i and phase i+1) as an example. Figure 4 In the example, the i-th phase rectifier circuit is the A-phase rectifier circuit, and the (i+1)-th phase rectifier circuit is the B-phase rectifier circuit, where i ≥ 1.

[0047] See Figure 4 As shown, both phase A and phase B rectifier circuits are H-bridge rectifier circuits. Taking phase A rectifier circuit as an example, its first bridge arm includes the first transistor D. AH1 Second transistor D AL1 And the first current-sharing capacitor C1, the second bridge arm of which includes the third transistor D AH2 The fourth transistor Q AS The second current-sharing capacitor C2. The first bridge arm of the B-phase rectifier circuit includes the first transistor D. BH1 Second transistor D BL1 The second bridge arm of the B-phase rectifier circuit includes the third transistor D. BH2 and the fourth transistor Q BS .

[0048] For the A-phase rectifier circuit, the first transistor D AH1 One end is connected to the third transistor D AH2 One end is connected and connected to one terminal of the output power supply Vout, the second transistor D AL1 One end is connected to the fourth transistor Q AS One end of the transistor is connected to the other terminal of the output power supply Vout. The first transistor D... AH1 The other end is connected to one terminal of the first current-sharing capacitor C1, and the second transistor D AL1 The other end is connected to the other terminal of the first current-sharing capacitor C1, serving as the output terminal C of the first bridge arm. The third transistor D... AH2 The other end is connected to one terminal of the second current-sharing capacitor C2, and the fourth transistor Q. AS The other end is connected to the other terminal of the second current-sharing capacitor C2, serving as the output terminal D of the second bridge arm. The output terminal C of the first bridge arm is connected through the rectifier capacitor C... bA Connecting transformer T rA The secondary side of the second bridge arm, with its output terminal D connected to transformer T, is one pole of the second bridge arm. rA The other pole of the secondary side.

[0049] For the B-phase rectifier circuit, the first transistor D BH1 One end is connected to the first transistor D AH1 On the bridge arm between the first current-sharing capacitor C1, the third transistor D BH2One end is connected to the third transistor D AH2 On the bridge arm between the second current-sharing capacitor C2 and the second transistor D. BL1 One end is connected to the fourth transistor Q BS One end of the transistor is connected and connected to the output power supply Vout. The second transistor D BL1 The other end is connected to the first transistor D BH1 The other end is connected as the output terminal E of the first bridge arm, and the output terminal E is connected through the rectifier capacitor C. bB Connecting transformer T rB The secondary side of the fourth transistor Q. BS The other end is connected to the third transistor D BH2 The other end is connected as the output terminal F of the second bridge arm, and the output terminal F is connected to the transformer T. rB The other pole of the secondary side.

[0050] In the embodiments described in this specification, the multiple transistors included in the H-bridge rectifier circuit in each phase can be diodes, triodes, MOSFETs, etc., and this specification does not impose any restrictions on this. For example, in one example, the four transistors included in the above-mentioned rectifier circuit in each phase can be diodes. Diodes allow current to conduct in one direction, and the current conduction direction of the four diodes is the same.

[0051] In the embodiments described in this specification, by connecting the bridge arm of the (i+1)th phase to the bridge arm of the ith phase, and by setting two rectifier capacitors in the bridge arm of the ith phase rectifier circuit, automatic current sharing between the two phases can be achieved, thereby realizing current self-balancing. The following will illustrate this further. Figure 4 Taking this as an example, the principle of self-balancing between phase A current and phase B current will be explained.

[0052] In one example, on the primary circuit side, the A-phase input current and the B-phase input current can work alternately with a duty cycle of 0.5 and a phase difference of 180 degrees. That is, on the primary circuit side, the duty cycle of the drive pulse signal of each switch is 50%. In steady state, in one switching cycle of 2T, the on and off time of each switch is T, and the drive signals are complementary.

[0053] Figure 5a The diagram shows the current flow direction in the secondary circuit when phase A is operating. Figure 5b This diagram shows the current flow direction in the secondary circuit when the B-phase current is operating. Figure 5a and Figure 5b In the diagram, the red arrow represents the phase A current i. A The flow path, the purple arrow indicates the B-phase current i B The flow path.

[0054] like Figure 5aAs shown, when phase A is powered, due to the 180-degree phase difference, the input current Vin charges phase A, and the first current-sharing capacitor C1 on the secondary circuit side charges phase A through the phase A current i. A During charging, the discharge current i of phase B B The second current-sharing capacitor C2 is charged. For example... Figure 5b As shown, when phase B is powered, the input current Vin charges phase B, and the second current-sharing capacitor C2 on the secondary circuit side charges phase A current i. A During discharge, the charging current i of phase B B Charge the first current-sharing capacitor C1.

[0055] Therefore, it can be understood that both the first current-sharing capacitor C1 and the second current-sharing capacitor C2 are connected to the B-phase current i. B Charging is performed through phase A current i A During discharge, according to the law of charge conservation, the current i in phase A is... A and B-phase current i B It can automatically share current and achieve current balance.

[0056] Additionally, it is worth noting that in Figure 4 The example only includes a two-phase rectifier circuit (phases A and B). The circuit principle described in this specification can be extended to LLC circuits with more phases. For example, in... Figure 4 Based on this, a third phase circuit, such as a C-phase rectifier circuit, can be added. In this case, the structure of the A-phase rectifier circuit can be referenced, with two current-sharing capacitors placed on the two bridge arms of the B-phase rectifier circuit. Then, the bridge arms of the C-phase rectifier circuit are connected to the two bridge arms of the B-phase rectifier circuit respectively. Its circuit structure and principle are the same as... Figure 4 , 5a Similar to 5b, those skilled in the art can undoubtedly understand and fully implement it in conjunction with the above, and this specification will not elaborate further.

[0057] As can be seen from the above, the LLC circuit of the embodiment of this specification can achieve high power output and a wide voltage gain range by connecting multi-phase LLC circuits in parallel. Furthermore, the improved rectifier circuit structure achieves current self-balancing, eliminating the need for complex current sharing control circuits, reducing circuit cost and transformer size, and facilitating the miniaturization and high power of charging devices.

[0058] In some embodiments, the four transistors in each rectifier circuit of the resonant converter circuit provided in this specification can be diodes. In other embodiments, the fourth transistor on the second bridge arm of each rectifier circuit can be a MOSFET. By controlling the on / off state of the MOSFET, the switching between "voltage doubling rectification" and "full-bridge rectification" modes can be realized on the basis of the above circuit, further widening the voltage gain of the LLC circuit and adapting to more application scenarios with wide voltage requirements.

[0059] See Figure 4 As shown, the fourth transistor Q in the A-phase rectifier circuit AS The fourth transistor Q of the B-phase rectifier circuit BS Using a MOSFET, which is a transistor switch that can be controlled to turn on and off, in the embodiments of this specification, the switching of LLC between two operating modes can be achieved by controlling the on and off of the fourth transistor.

[0060] In some implementations, the MOS transistor of the fourth transistor includes a parasitic diode, also called a body diode, and the current direction of the parasitic diode is the same as that of other diodes in the rectifier circuit.

[0061] In some embodiments, the resonant converter circuit provided in this specification also includes a control circuit. The control circuit controls the on / off state of each switching transistor in the primary circuit, thereby enabling the resonant converter to operate. Simultaneously, the control circuit can also control the on / off state of a fourth transistor. When the MOSFET of the fourth transistor is in a state of long-term off, current can flow through the parasitic diode, thus the fourth transistor performs the same function as a conventional diode, and the rectifier circuit is a full-bridge rectifier circuit. When the MOSFET is in a state of long-term on, the rectifier capacitor C... bA and C bB Forming a voltage multiplier rectifier module, transistor D AH2 and D BH2 It is completely off and does not conduct. Therefore, by switching the fourth transistor on and off, two different output architectures with different gains can be achieved.

[0062] Figure 6 The voltage gain curves of the LLC circuit described in this specification and a conventional LLC circuit are shown. Figure 6 The horizontal axis represents frequency, and the vertical axis represents the output voltage range. The "traditional LLC converter" curve represents, for example... Figure 1 The voltage gain curves of the conventional LLC circuit shown are as follows: the "full-bridge rectification" curve represents the voltage gain curve when the LLC operates in full-bridge rectification mode (i.e., the fourth transistor is always off) in the embodiment of this specification, and the "voltage doubler rectification" curve represents the voltage gain curve when the LLC operates in voltage doubler rectification mode (i.e., the fourth transistor is on) in the embodiment of this specification.

[0063] By comparison Figure 6As can be seen, under the same conditions, the circuit architecture of the implementation method in this specification not only has a better voltage gain range than the traditional solution, but also can achieve a higher gain voltage range by switching the rectification mode, greatly increasing the upper limit of voltage gain, and can achieve a 2-4 times boost of the base voltage. Furthermore, by adjusting the switching frequency and a reasonable transformer turns ratio, the entire device can be further boosted within a very narrow frequency variation range, adapting to more application scenarios with wide voltage requirements.

[0064] As described above, in the embodiments of this specification, high-power power output can be achieved through parallel connection of multi-phase LLC circuits, realizing a wide voltage gain range. Furthermore, the charge balance principle of capacitors enables current self-balancing, reducing current stress and eliminating the need for complex current sharing control circuits, thus lowering circuit cost and transformer size. This facilitates the miniaturization and high power output of charging devices. Moreover, the MOSFETs enable switching between voltage doubler rectification and full-bridge rectification modes on the secondary circuit side, achieving a higher gain voltage range and significantly increasing the upper limit of voltage gain, adapting to more application scenarios with wide voltage requirements.

[0065] In some embodiments, this specification provides a charging device that may include the resonant converter circuit of any of the above embodiments, thereby achieving the circuit functions and beneficial effects described above. In the embodiments of this specification, the charging device may be any suitable type of device, such as a car charging station, a laptop power adapter, a mobile terminal power adapter, etc., and this specification does not impose any limitations on this.

[0066] In some embodiments, this specification provides an electronic device including a device body and a charging device according to any of the above embodiments. The charging device provides power and / or charges the device body through the circuit structure and principle described above. In the embodiments of this specification, the electronic device can be any suitable type of device, such as new energy vehicles, laptops, mobile terminals, wearable devices, etc., and this specification does not impose any limitations on this.

[0067] Obviously, the above embodiments are merely examples for clear illustration and are not intended to limit the embodiments. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all embodiments here. However, obvious variations or modifications derived therefrom remain within the scope of protection created by this specification.

Claims

1. A resonant converter circuit, characterized in that, The transformer includes a primary circuit located on the primary side and a secondary circuit located on the secondary side. The primary circuit includes an N-phase parallel resonant transformer circuit, and the secondary circuit includes an N-phase rectifier circuit, where N ≥ 2. The rectifier circuits are full-bridge rectifier circuits, and for adjacent i-th and (i+1)-th phase rectifier circuits in the N-phase rectifier circuits, i ≥ 1. The first bridge arm of the i-th phase rectifier circuit includes a first transistor, a second transistor, and a first current sharing capacitor; the second bridge arm of the i-th phase rectifier circuit includes a third transistor, a fourth transistor, and a second current sharing capacitor. One end of the first bridge arm of the (i+1)th phase rectifier circuit is connected to the output power supply, and the other end is connected between the first transistor and the first current sharing capacitor. One end of the second bridge arm of the (i+1)th phase rectifier circuit is connected to the output power supply, and the other end is connected between the third transistor and the second current sharing capacitor.

2. The resonant converter circuit according to claim 1, characterized in that, The output terminal of the first bridge arm of the rectifier circuit in each phase is connected to the secondary side of the transformer through a rectifier capacitor. The output terminal of the first bridge arm is located between the first current sharing capacitor and the second transistor. The output terminal of the second bridge arm of the rectifier circuit is located between the second current sharing capacitor and the fourth transistor.

3. The resonant converter circuit according to claim 1, characterized in that, With N=2, the two-phase rectifier circuit operates alternately with a 180-degree phase difference and a duty cycle of 0.

5.

4. The resonant converter circuit according to any one of claims 1 to 3, characterized in that, In each phase rectifier circuit, the fourth transistor of the second bridge arm is a MOSFET, and the other transistors are diodes. The MOSFET includes a parasitic diode, wherein the current conduction direction of the parasitic diode and the other diodes is the same.

5. The resonant converter circuit according to claim 4, characterized in that, It also includes a control circuit, which is used to control the on / off state of the MOS transistor.

6. The resonant converter circuit according to claim 1, characterized in that, When i=1, the first and second bridge arms of the i-th phase rectifier circuit are connected in parallel, and one end of the parallel connection is connected to one of the poles of the output power supply, while the other end of the parallel connection is connected to the other pole of the output power supply.

7. The resonant converter circuit according to claim 1, characterized in that, The primary circuit includes a full-bridge input circuit and the resonant converter circuit. The bridge arm output of the full-bridge input circuit is connected to the resonant converter circuit, which is located on the primary side of the transformer.

8. The resonant converter circuit according to claim 7, characterized in that, A filter capacitor is connected in parallel between the full-bridge input circuit and the input-side power supply.

9. A charging device, characterized in that, Includes the resonant converter circuit according to any one of claims 1 to 8.

10. An electronic device, characterized in that, It includes a device body and a charging device, wherein the charging device is used to supply power to the device body, and the charging device is the charging device as described in claim 9.

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