Power supply device, resonant converter circuit and control method thereof

Abstract

This application discloses a power supply device, a resonant converter circuit, and a control method thereof. The circuit includes: an inverter circuit, a resonant circuit, a rectifier circuit, a switch, and a second inductor. The inverter circuit is connected to the resonant circuit and is used to convert direct current (DC) into alternating current (AC) and output it to the resonant circuit. The resonant circuit is connected to the rectifier circuit and is used to resonate and convert the AC power and output it to the rectifier circuit. The rectifier circuit is used to output DC power. The resonant circuit includes a first inductor and a first capacitor, which are connected in series with the first inductor, the first capacitor, and the second inductor. The switch is connected in parallel with the second inductor, and the rectifier circuit is connected to both ends of the second inductor. Through this application embodiment, the output voltage gain of the resonant converter can be increased without affecting the efficiency of the resonant converter, thereby extending the hold-up time.

Description

Technical Field

[0001] This application relates to the field of control circuits, and more particularly to a power supply device, a resonant converter circuit, and a control method thereof. Background Technology

[0002] Figure 1 This is a schematic diagram of the existing power system structure, such as... Figure 1 As shown, the power supply system includes a front-end converter 101, an electrolytic capacitor 102, and a back-end converter 103. Figure 1 In the server power supply or communication power supply system shown, when the input power supply of the front-end converter 101 fails, the powered device needs to perform data backup, that is, for a period of time (sustainment time T) after the input power supply fails. hold Within the stage of power supply, the subsequent converter needs to maintain the stability of the output voltage. In order to achieve higher efficiency and higher power density, resonant converters (LLC converters) are generally selected for the subsequent converter.

[0003] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Summary of the Invention

[0004] After the input power supply is lost, the input voltage of the subsequent converter will decrease to support the stability of the output voltage. Figure 2 This is a diagram illustrating the duration, as shown below. Figure 2 As shown, V bulk1 This is the normal operating bus voltage, V bulk2 This is the bus voltage at the end of the sustaining time. Because... In order to satisfy the duration T hold According to the requirements, in related technologies, a bus capacitor value C with a larger capacitance can be selected. bulk However, large-capacitance capacitors result in larger volumes, affecting the improvement of power density; alternatively, the bus voltage V could be increased. bulk1 However, in order for the resonant converter to operate at a high efficiency, the bus voltage V bulk1 Only fine-tuning is possible; alternatively, the bus voltage V can be reduced. bulk2 But the bus voltage V bulk2 The premise for reducing efficiency is that the LLC converter has a large output voltage gain. However, if the output voltage gain is increased simply by designing the LLC parameters, the efficiency of the LLC converter will be reduced.

[0005] To address at least one of the aforementioned problems, embodiments of this application provide a power supply device, a resonant converter circuit, and a control method thereof.

[0006] The specific technical solution of this application embodiment is as follows:

[0007] According to a first aspect of the embodiments of this application, a resonant converter circuit is provided, wherein the circuit includes: an inverter circuit, a resonant circuit, a rectifier circuit, a switch, and a second inductor;

[0008] The inverter circuit is connected to the resonant circuit and is used to convert direct current into alternating current and output it to the resonant circuit; the resonant circuit is connected to the rectifier circuit and is used to convert the alternating current into resonant current and output it to the rectifier circuit; the rectifier circuit is used to output direct current.

[0009] The resonant circuit includes a first inductor and a first capacitor, which are connected in series; the switch is connected in parallel with the second inductor, and the rectifier circuit is connected to both ends of the second inductor.

[0010] According to a second aspect of the embodiments of this application, a control method for a resonant converter circuit is provided, wherein the method includes:

[0011] The output voltage of the resonant converter circuit described in the first aspect is sampled to generate an output voltage sampling signal;

[0012] A control signal is generated based on the output voltage sampling signal;

[0013] The switch is turned on or off according to the control signal.

[0014] According to a third aspect of the embodiments of this application, a power supply device is provided, which includes the resonant converter circuit described in the first aspect.

[0015] The beneficial effect of this application embodiment is that by connecting a switch in parallel across the inductor of the resonant converter and short-circuiting the switch, the energy of the resonant inductor and resonant capacitor is increased, thereby improving the output voltage gain of the resonant converter without affecting the efficiency of the resonant converter, and thus extending the sustaining time.

[0016] Specific embodiments of this application are disclosed in detail with reference to the following description and accompanying drawings, indicating how the principles of this application can be adopted. It should be understood that the embodiments of this application are not limited in scope. Within the spirit and scope of the appended claims, embodiments of this application include many changes, modifications, and equivalents. Features described and / or shown for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments. Attached Figure Description

[0017] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this application in any way. Furthermore, the shapes and scales of the components in the drawings are merely illustrative to aid in understanding this application and do not specifically limit the shapes and scales of the components. Those skilled in the art, guided by the teachings of this application, can select various possible shapes and scales to implement this application according to specific circumstances.

[0018] Figure 1 This is a schematic diagram of the existing power system structure;

[0019] Figure 2 This is a diagram illustrating the current maintenance time;

[0020] Figure 3 This is a schematic diagram of the resonant converter circuit according to an embodiment of this application;

[0021] Figure 4A This is a schematic diagram of the structure of a full-bridge inverter circuit according to an embodiment of this application;

[0022] Figures 4B to 4C This is a schematic diagram of the structure of a half-bridge inverter circuit according to an embodiment of this application;

[0023] Figures 5A to 5B This is a schematic diagram showing the connection between the first capacitor and the half-bridge inverter circuit in an embodiment of this application;

[0024] Figure 6A and Figure 6B This is a schematic diagram of a portion of the rectifier circuit structure according to an embodiment of this application;

[0025] Figure 7A and Figure 7B This is a schematic diagram of the rectifier circuit according to an embodiment of this application;

[0026] Figure 8 This is a schematic diagram of the filter circuit according to an embodiment of this application;

[0027] Figure 9 This is a schematic diagram of the rectifier circuit according to an embodiment of this application;

[0028] Figures 10A to 10D This is a schematic diagram of the structure of switch 304 according to an embodiment of this application;

[0029] Figure 10E This is a schematic diagram of the connection between switch 304 and bidirectional TVS tube according to an embodiment of this application;

[0030] Figure 11 This is a schematic diagram of the resonant converter circuit according to an embodiment of this application;

[0031] Figure 12 This is a schematic diagram of the switching cycle according to an embodiment of this application;

[0032] Figure 13 This is a schematic diagram of the operating frequency and conduction time of an embodiment of this application;

[0033] Figure 14 This is a schematic diagram of the control method of the resonant converter according to an embodiment of this application;

[0034] Figure 15 This is a schematic diagram of the control method of the resonant converter according to an embodiment of this application. Detailed Implementation

[0035] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate this application and are not intended to limit the scope of the present invention. After reading this application, any modifications of this application by those skilled in the art in various equivalent forms fall within the scope defined by the appended claims.

[0036] In the embodiments of this application, the terms "first," "second," etc., are used to distinguish different elements by name, but do not indicate the spatial arrangement or chronological order of these elements, and these elements should not be limited by these terms. The term "and / or" includes any one or more of the terms listed in association and all combinations thereof. The terms "comprising," "including," "having," etc., refer to the presence of the stated features, elements, components, or assemblies, but do not exclude the presence or addition of one or more other features, elements, components, or assemblies.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0038] First aspect of the embodiments

[0039] An embodiment of the first aspect of this application provides a resonant converter circuit. Figure 3 This is a schematic diagram of the resonant converter circuit according to an embodiment of this application, as shown below. Figure 3 As shown, the circuit includes: an inverter circuit 301, a resonant circuit 302, a rectifier circuit 303, a switch 304, and a second inductor 305;

[0040] The inverter circuit 301 is connected to the resonant circuit 302 and is used to convert DC power into AC power and output it to the resonant circuit; the resonant circuit 301 is connected to the rectifier circuit 303 and is used to resonate and convert the AC power and output it to the rectifier circuit 303; the rectifier circuit 303 is used to output DC power.

[0041] The resonant circuit 302 includes a first inductor 3021, a first capacitor 3022, and a second inductor 305 connected in series; the switch 304 is connected in parallel with the second inductor 305, and the rectifier circuit 303 is connected to both ends of the second inductor 305.

[0042] In some embodiments, the inverter circuit 301 can convert direct current (DC) to alternating current (AC). The inverter circuit 301 includes a DC positive input terminal, a DC negative input terminal, an inverter output terminal 1, and an inverter output terminal 2. The DC positive input terminal and the DC negative input terminal are used for inputting DC power.

[0043] In some embodiments, the inverter circuit 301 may be a full-bridge inverter circuit or a half-bridge inverter circuit, but this application embodiment is not intended to limit it. Figure 4A This is a schematic diagram of a full-bridge inverter circuit. Figures 4B to 4C This is a schematic diagram of a half-bridge inverter circuit. Figure 4A As shown, the inverter circuit 301 includes a first power switch S1, a second power switch S2, a third power switch S3, and a fourth power switch S4. The first terminal of the first power switch S1 is connected to the positive DC input terminal, and the second terminal of the first power switch S1 is connected to the inverter output terminal 1. The first terminal of the second power switch S2 is connected to the inverter output terminal 1, and the second terminal of the second power switch S2 is connected to the negative DC input terminal. The first terminal of the third power switch S3 is connected to the positive DC input terminal, and the second terminal of the third power switch S3 is connected to the inverter output terminal 2. The first terminal of the fourth power switch S4 is connected to the inverter output terminal 2, and the second terminal of the fourth power switch S4 is connected to the negative DC input terminal.

[0044] like Figure 4BAs shown, the inverter circuit 301 includes a first power switch S5 and a second power switch S6. The first terminal of the first power switch S5 is connected to the DC positive input terminal, the second terminal of the first power switch S5 is connected to the inverter output terminal 1, the first terminal of the second power switch S6 is connected to the inverter output terminal 1, the second terminal of the second power switch S6 is connected to the inverter output terminal 2, and the DC negative input terminal is electrically connected to the inverter output terminal 2.

[0045] like Figure 4C As shown, the inverter circuit 301 includes a first power switch S7 and a second power switch S8. The first terminal of the first power switch S7 is connected to the inverter output terminal 1, the second terminal of the first power switch S7 is connected to the inverter output terminal 2, the first terminal of the second power switch S8 is connected to the inverter output terminal 2, the second terminal of the second power switch S8 is connected to the DC negative input terminal, and the DC positive input terminal is electrically connected to the inverter output terminal 1.

[0046] The first and second terminals mentioned above can be the D (drain or collector) and S (source or emitter), but this embodiment is not limited to these. The switching transistors mentioned above include various power semiconductor switching devices such as power MOSFETs, IGBTs, BJTs, thyristors, and IGCTs.

[0047] The components and connections in the inverter circuit 301 described above are merely illustrative examples and are not intended to limit the scope of this application.

[0048] In some embodiments, the inverter circuit 301 is connected to the resonant circuit 302, and the alternating current output by the inverter circuit 301 is applied to both ends of the resonant circuit 302 to generate high-frequency resonance. The resonant circuit 302 includes a first inductor (Lr) 3021 and a first capacitor (Cr) 3022 connected in series. The first inductor Lr is a resonant inductor, and the first capacitor Cr is a resonant capacitor. The second inductor (Lm) 305 is connected in series with the first inductor 3021 and the first capacitor 3022. For example, the second inductor is located between the first inductor and the first capacitor, but this application does not limit the connection order of the first inductor, the second inductor, and the first capacitor.

[0049] In some embodiments, Figure 5A and Figure 5B This is a schematic diagram showing the connection between the first capacitor and the half-bridge inverter circuit, as shown below. Figure 5BAs shown, the first capacitor Cr can be composed of two parallel capacitors, namely, a first sub-capacitor Cr1 and a second sub-capacitor Cr2 connected in parallel. One end of the first and second sub-capacitors connected in parallel is connected to the DC positive input terminal or the DC negative input terminal of the inverter circuit 301, and one end of the first inductor is connected to the inverter output terminal 1. Based on this, the connection points of the first and second sub-capacitors to the inverter circuit can be separated and connected to the DC positive input terminal and the DC negative input terminal of the inverter circuit respectively. One end of the first inductor is connected to the inverter output terminal 1, i.e., as shown... Figure 5A As shown, the Figure 5A The circuit shown can achieve better suppression of electromagnetic interference. The above connection relationship is only an example and is not intended to limit the scope of this application.

[0050] In some embodiments, the positive and negative output terminals of the resonant circuit 302 are connected to both ends of the switch 304 and the two ends of the rectifier circuit 303, that is, the switch 304 and the rectifier circuit 303 are connected in parallel with the second inductor 305. These will be explained separately below.

[0051] In some embodiments, the rectifier circuit 303 can convert the AC power output by the resonant circuit 302 into DC power. The rectifier circuit 303 can be a full-bridge rectifier circuit or a half-bridge rectifier circuit. The rectifier circuit 303 includes a first connection terminal, a second connection terminal, a DC positive output terminal, and a DC negative output terminal. The DC positive output terminal and the DC negative output terminal are used for DC power output. The first connection terminal and the second connection terminal can be connected to the output positive connection terminal and the output negative connection terminal of the resonant circuit 302, respectively. Alternatively, the first connection terminal and the second connection terminal can be connected to the two ends of the second inductor 305, respectively.

[0052] In some embodiments, the rectifier circuit 303 includes a rectifier tube 3031, which includes at least one diode and / or at least one synchronous rectifier tube. That is, the rectifier tubes can all be diodes, or all be synchronous rectifier tubes, or a combination of diodes and synchronous rectifier tubes. Figure 6A and Figure 6B This is a partial structural schematic diagram of the rectifier circuit 303 in an embodiment of this application (using a full-bridge rectifier circuit as an example), as shown below. Figure 6A and 6B As shown, the rectifier circuit 303 includes four rectifier diodes. Figure 6A ), or both are synchronous rectifier tubes ( Figure 6BThe second terminal of rectifier D1 and the first terminal of rectifier D2 are connected to the first connection terminal. The second terminals of rectifier D3 and the first terminals of rectifier D4 are connected to the second connection terminal. The first terminals of rectifier D1 and D3 are connected to the positive DC output terminal, and the second terminals of rectifier D2 and D4 are connected to the negative DC output terminal. The above example uses 4 as a quantity, but this quantity is not a limitation. For example, the quantity can also be 1, 2, or 3, etc., which will not be listed here.

[0053] In some embodiments, the rectifier circuit 303 may further include a second capacitor 3034 (output capacitor), the two ends of which are connected to the DC positive output terminal and the DC negative output terminal respectively, that is, connected in parallel with the two ends of the rectifier circuit 303.

[0054] In some embodiments, the rectifier circuit may optionally include a transformer 3032, which includes a primary winding 30321 and a secondary winding 30322. The two ends of the primary winding are connected to the positive output terminal and the negative output terminal of the resonant circuit 302, respectively. The secondary winding can be a two-terminal structure or a three-terminal structure with a center tap, and this application does not limit it to this. Figure 7A and Figure 7B This is a schematic diagram of the rectifier circuit 303 according to an embodiment of this application, as shown below. Figure 7A As shown, the rectifier circuit includes a secondary winding (two-terminal structure), the two ends of which are connected to a first connection terminal and a second connection terminal, respectively; as Figure 7B As shown, the rectifier circuit includes two secondary windings (three-terminal structure). The two ends of one of the secondary windings are connected to the first pole of rectifier diode D5 and the DC positive output terminal, respectively. The two ends of the other secondary winding are connected to the first pole of rectifier diode D6 and the DC positive output terminal, respectively. The second poles of rectifier diode D5 and rectifier diode D6 are connected to the DC negative output terminal.

[0055] In some embodiments, the rectifier circuit may optionally include a filter circuit 3033, which may be an LC filter circuit. Figure 8 This is a schematic diagram of the filter circuit, as shown below. Figure 8 As shown, the filter circuit includes a third inductor 30331 and a third capacitor 30332 connected in series. One end of the third inductor 30331 is connected to one end of the second capacitor 3034, and one end of the third capacitor 30332 is connected to the other end of the second capacitor 3034. The other end of the third inductor 30331 is connected to the other end of the third capacitor 30332. The two ends of the third capacitor 30332 serve as the positive DC output terminal and the negative DC output terminal of the rectifier circuit.

[0056] Figure 9This is a schematic diagram of the rectifier circuit structure in an embodiment of this application, as shown below. Figure 9 As shown, the rectifier circuit 303 includes the rectifier tube 3031, the second capacitor 3034, the transformer 3032, and the filter circuit 3033 as described above. However, the embodiments of this application are not limited thereto. The transformer 3032 and the filter circuit 3033 are optional.

[0057] In some embodiments, the second inductor can be integrated into the transformer of the rectifier circuit as the magnetizing inductance of the transformer (e.g., the magnetizing inductance value of the primary side of the transformer). However, the embodiments of this application are not limited thereto. The second inductor can also be independent of the rectifier circuit as an independent inductor. For specific examples, please refer to related technologies, which will not be listed here.

[0058] In this embodiment, a switch 304 is connected in parallel across the two ends of the second inductor. By short-circuiting this switch, the two ends of the second inductor are short-circuited, thereby increasing the voltage across the first inductor and the first capacitor connected in series with the second inductor. During the short-circuit process, the energy of the first inductor and the first capacitor is stored, thereby improving the output voltage gain of the resonant converter without affecting its efficiency, and thus extending the hold-up time. The following is a detailed description.

[0059] In some embodiments, the switch 304 is connected in parallel with the second inductor 305, or the positive and negative output terminals of the resonant circuit 302 are connected to the two ends of the switch 304, or the two ends of the switch 304 are connected to the first and second connection terminals of the rectifier circuit 303.

[0060] In some embodiments, the switch 304 can be a short-circuit switch, and its specific implementation can be found in related technologies, which will not be repeated here. The switch 304 can also be a bidirectional switch, using a back-to-back series connection of switching transistors. Figures 10A to 10D This is a schematic diagram of the structure of switch 304 according to an embodiment of this application, as shown below. Figures 10A to 10D As shown, the back-to-back switching transistor can be composed of two insulated-gate bipolar transistors (IGBTs) or metal-oxide-semiconductor field-effect transistors (MOS) connected in series. This is merely an illustrative example, and the embodiments of this application are not intended to limit the scope. As mentioned above, the switching transistor can also be various power semiconductor switching devices, including bipolar junction transistors (BJTs), thyristors, integrated gate commutated thyristors (IGCTs), etc.

[0061] like Figure 10A and Figure 10B As shown, the drains (D) of two back-to-back switching transistors are connected, and the source (S) of these two transistors are respectively connected to the two ends of the second inductor 305, as shown. Figure 10C and Figure 10DAs shown, the source (S) terminals of two back-to-back switching transistors are connected, and the drain (D) terminals of the two switching transistors are respectively connected to the two ends of the second inductor 305.

[0062] In some embodiments, the two ends of the switch 304 are also connected to a bidirectional transient voltage suppressor diode (bidirectional TVS diode), which is used for voltage clamping. Figure 10E This is a schematic diagram showing the connection between the 304 switch and the bidirectional TVS diode, as shown below. Figure 10E As shown, the bidirectional TVS diode 306 is connected across the two ends of the switch 304. The bidirectional TVS diode can be an integrated bidirectional TVS diode or two TVS diodes in opposite directions connected in series. This can reduce the bidirectional switching voltage stress caused by parasitic inductance or leakage inductance.

[0063] Figure 11 This is a schematic diagram of the resonant converter circuit according to an embodiment of this application, as shown below. Figure 11 As shown, the circuit includes: an inverter circuit 401, a resonant circuit 402, a rectifier circuit 403, a switch 404, and a second inductor 405. A drive control circuit 406 is connected to the switch 404 and is used to output a control signal to the switch. The implementation of the inverter circuit 401, resonant circuit 402, rectifier circuit 403, switch 404, and second inductor 405 is the same as that of the inverter circuit 301, resonant circuit 302, rectifier circuit 303, switch 304, and second inductor 305, and the repeated parts will not be described again.

[0064] In some embodiments, the drive control circuit 406 controls the switch to be turned on (closed, switched on) during a predetermined time period in each switching cycle to short-circuit the two ends of the second inductor. This increases the voltage across the first inductor and the first capacitor connected in series with the second inductor. During the short-circuit process, the energy of the first inductor and the first capacitor is stored, thereby improving the output voltage gain of the resonant converter without affecting its efficiency.

[0065] In some embodiments, the switching period is the input voltage V of the resonant circuit 302. ab The switching period (T) is greater than the resonant period of the first inductor and the first capacitor, which is [missing information].

[0066] In some embodiments, Figure 12 This is a schematic diagram of the switching cycle in an embodiment of this application, such as... Figure 12 As shown, this switching cycle includes symmetrical positive and negative voltage levels, with both positive and negative voltage levels having a duration of [missing information]. The predetermined time period is the later part of the positive and negative half-cycles of the switching cycle, T. C In other words, the control cycle of this switch is... Therefore, the drive control circuit 406 operates in the later time period T of the positive and negative half-cycles of the switching cycle. C Turn on switch 404 to reduce the turn-on and turn-off current of switch 404, and short-circuit the two ends of the second inductor.

[0067] In some embodiments, the drive control circuit 406 includes:

[0068] The sampling circuit 4061 is used to sample the output voltage of the rectifier circuit and generate an output voltage sampling signal;

[0069] Control circuit 4062 is electrically connected to the sampling circuit and generates a control signal based on the output voltage sampling signal;

[0070] The drive circuit 4063 is connected to the control circuit and the switch, and drives the switch to turn on or off according to the control signal.

[0071] In some embodiments, the sampling circuit 4061 includes a third connection terminal, a fourth connection terminal, and a fifth connection terminal. The third connection terminal and the fourth connection terminal are respectively connected to the two ends of the rectifier circuit 403, and the fifth connection terminal is connected to the sixth connection terminal of the control circuit 4062. The structure of the sampling circuit 4061 can adopt the prior art, which will not be described in detail here.

[0072] In some embodiments, the control circuit 4062 further includes a seventh connection terminal, an eighth connection terminal, and a ninth connection terminal. The seventh connection terminal is used for inputting the output voltage reference signal (a preset voltage signal). The eighth and ninth connection terminals are respectively connected to the tenth and eleventh connection terminals of the drive circuit 4063. The drive circuit 4063 further includes a twelfth and a thirteenth connection terminal. The twelfth connection terminal is electrically connected to the switch 404, and the thirteenth connection terminal is electrically connected to the inverter circuit 401.

[0073] In some embodiments, the control circuit 4062 generates control signals based on the comparison result of the output voltage sampling signal and the output voltage reference signal, including a first drive signal and a second drive signal. The first drive signal is output to the drive circuit 4063 through the connection of the eighth connection terminal and the tenth connection terminal to control the conduction and disconnection of the switch 404. The second drive signal is output to the drive circuit 4063 through the connection of the ninth connection terminal and the eleventh connection terminal to control the conduction and disconnection of the switching transistor in the inverter circuit 401.

[0074] In some embodiments, since the operating frequency of the inverter circuit 401 is equal to the reciprocal of the sum of the on-time and off-time of the switching transistor of the inverter circuit 401, the drive circuit 4063 controls the switching transistor of the inverter circuit 401 to be turned on or off according to the second drive signal, thereby controlling the operating frequency of the inverter circuit 401. The duty cycle of the switching transistor of the inverter circuit 401 is 50%. For details, please refer to the prior art, which will not be elaborated here.

[0075] In some embodiments, the drive circuit also controls the switch 404 to be turned on or off according to the first drive signal. Figure 13 The inverter circuit operating frequency and switching on-time T in the embodiments of this application are... on Control logic diagram, such as Figure 13 As shown, after the operating frequency reaches the preset frequency, the conduction time of control switch 404 is T. C .

[0076] The following describes the control circuit's workflow: When the output voltage sampling signal is less than the output voltage reference signal, the inverter circuit's operating frequency is reduced, and the resonant converter circuit's output voltage gain is increased to improve the output voltage. When the output voltage sampling signal is greater than the output voltage reference signal, the inverter circuit's operating frequency is increased, and the resonant converter circuit's output voltage gain is decreased to reduce the output voltage. When the inverter circuit's operating frequency reaches the preset frequency, the resonant converter circuit's output voltage gain is adjusted by regulating the switch's on-time. Specifically, when the output voltage sampling signal is less than the output voltage reference signal, the switch's on-time is increased to improve the resonant converter circuit's output voltage gain, thus increasing the output voltage; when the output voltage sampling signal is greater than the output voltage reference signal, the switch's on-time is decreased to reduce the resonant converter circuit's output voltage gain, thus reducing the output voltage. It should be noted that regardless of whether the switch's on-time is increased or decreased, this on-time always falls within the later time period T of the positive and negative half-cycles of the switching cycle. C In other words, when the output voltage sampling signal is less than the output voltage reference signal, T is increased. C When the output voltage sampling signal is greater than the output voltage reference signal, reduce T. C .

[0077] It should be noted that the circuit in the above example may also include devices not shown in the figure. For details, please refer to the prior art. The embodiments of this application are not intended to be limiting, or the circuit is not necessarily required to include such devices. Figure 3 All the components shown are not listed here individually.

[0078] For the sake of simplicity, Figures 3 to 11The illustrations only demonstrate the connection relationships or signal flows between various components or modules; however, those skilled in the art should understand that various related technologies, such as electrical connections, can be employed. This application does not limit the scope of the embodiments described.

[0079] The above description uses the resonant converter circuit including the drive control circuit as an example, but the embodiments of this application are not limited thereto. The drive control circuit can also be independent of the resonant converter circuit to control and drive the inverter circuit and the switch.

[0080] The above embodiments are merely illustrative examples of embodiments of this application, but this application is not limited thereto, and appropriate modifications can be made based on the above embodiments. For example, the above embodiments can be used alone, or one or more of the above embodiments can be combined.

[0081] As can be seen from the above embodiments, by connecting a switch in parallel across the inductor of the resonant converter and short-circuiting the switch, the energy of the resonant inductor and resonant capacitor is increased, thereby improving the output voltage gain of the resonant converter without affecting its efficiency, and thus extending the sustaining time.

[0082] Second aspect of the embodiments

[0083] This application also provides a control method for a resonant converter circuit. Figure 14 This is a schematic diagram of the control method according to an embodiment of this application, as shown below. Figure 14 As shown, the control method includes:

[0084] 1401, samples the output voltage of the resonant converter circuit to generate an output voltage sampling signal;

[0085] 1402, Generate a control signal based on the output voltage sampling signal;

[0086] 1403, the switch is turned on or off according to the control signal.

[0087] In some embodiments, the implementation of the resonant converter circuit and the implementation of 1401-1403 can refer to the first aspect embodiment, and the repeated parts will not be described again.

[0088] In some embodiments, a control signal, including a first drive signal, can be generated based on the comparison result of the output voltage sampling signal and the output voltage reference signal. The conduction time of the switch in the resonant converter circuit is controlled according to the first drive signal. For details, please refer to the embodiments of the first aspect, which will not be repeated here.

[0089] In some embodiments, in 1402, the control signal further includes a second drive signal, and in 1403, the switching transistor of the inverter circuit is turned on and off according to the second drive signal to control (adjust) the operating frequency of the inverter circuit.

[0090] In some embodiments, in 1403, the switch is controlled to turn on after the operating frequency reaches a preset frequency, and the switch is controlled to turn on during a predetermined time period in each switching cycle to short-circuit the two ends of the second inductor. The switching cycle is longer than the resonant period of the first inductor and the first capacitor, and the predetermined time period is the later part of the positive and negative half-cycles of the switching cycle.

[0091] Figure 15 This is a schematic diagram of the control method according to an embodiment of this application, as shown below. Figure 15 As shown, the control method includes:

[0092] 1501, samples the output voltage of the resonant converter circuit to generate an output voltage sampling signal;

[0093] 1502, Generate a first drive signal and a second drive signal based on the output voltage sampling signal and the output voltage reference signal;

[0094] 1503, The switching transistor of the inverter circuit is turned on and off according to the second drive signal to control (adjust) the operating frequency of the inverter circuit;

[0095] 1504, after the operating frequency reaches the preset frequency, the switch is controlled to turn on and off according to the first drive signal.

[0096] In some embodiments, the implementation of the resonant converter circuit and the implementation of 1501-1504 can refer to the first aspect embodiment, and the repeated parts will not be described again.

[0097] In some embodiments, in 1504, the switch is controlled to be turned on during a predetermined time period of each switching cycle, and turned off during other time periods of the switching cycle. The switching cycle is longer than the resonant period of the first inductor and the first capacitor, and the predetermined time period is the later part of the positive and negative half-cycles of the switching cycle.

[0098] As can be seen from the above embodiments, by connecting a switch in parallel across the inductor of the resonant converter and short-circuiting the switch, the energy of the resonant inductor and resonant capacitor is increased, thereby improving the output voltage gain of the resonant converter without affecting its efficiency, and thus extending the sustaining time.

[0099] This application embodiment also provides a power supply device, such as a server power supply or a communication power supply, the power supply device as follows: Figure 1As shown, the subsequent converter includes the resonant converter circuit described in the first aspect embodiment, and the repeated parts will not be described again.

[0100] This application also provides a computer program in which, when executed in a power supply device or resonant converter circuit, the program causes a drive control circuit to perform the method described in the second aspect of the embodiment.

[0101] This application also provides a storage medium storing a computer program, wherein the computer program causes a drive control circuit to perform the method described in the second aspect of the embodiment.

[0102] The circuits / methods described in conjunction with the embodiments of this application can be directly embodied in hardware, software modules executed by a processor, or a combination of both. For example, one or more and / or one or more combinations of functional block diagrams shown in the figures can correspond to various software modules in a computer program flow, or to various hardware modules. These software modules can respectively correspond to... Figure 14 and Figure 15 The steps are shown. These hardware modules can be implemented by embedding these software modules, for example, using a field-programmable gate array (FPGA).

[0103] The software module can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. A storage medium can be coupled to the processor, enabling the processor to read information from and write information to the storage medium; or the storage medium can be an integral part of the processor. The processor and storage medium can reside in an ASIC. The software module can be stored in the memory of the information processing system or in a memory card that can be inserted into the information processing system.

[0104] One or more of the functional block diagrams and / or combinations thereof described in the figures can be implemented as a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, or any suitable combination thereof for performing the functions described in this application. One or more of the functional block diagrams and / or combinations thereof described in the figures can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in communication with a DSP, or any other such configuration.

[0105] The present application has been described above with reference to specific embodiments. However, those skilled in the art should understand that these descriptions are exemplary and not intended to limit the scope of protection of the present application. Those skilled in the art can make various modifications and variations to the present application based on its spirit and principles, and these modifications and variations are also within the scope of the present application.

Claims

1. A resonant converter circuit, characterized in that, The circuit includes: an inverter circuit, a resonant circuit, a rectifier circuit, a switch, and a second inductor; The inverter circuit is connected to the resonant circuit and is used to convert direct current into alternating current and output it to the resonant circuit; the resonant circuit is connected to the rectifier circuit and is used to convert the alternating current into resonant current and output it to the rectifier circuit; the rectifier circuit is used to output direct current. The resonant circuit includes a first inductor and a first capacitor, which are connected in series with the first inductor, the first capacitor, and a second inductor; the switch is connected in parallel with the second inductor, and the rectifier circuit is connected to both ends of the second inductor. Specifically, the switch is controlled to be turned on during a predetermined time period in each switching cycle. The predetermined time period is located in the later part of the positive and negative half-cycles. When the switch is turned on, the two ends of the second inductor are short-circuited to increase the energy of the first inductor and the first capacitor.

2. The circuit according to claim 1, characterized in that, The switch is a bidirectional switch, which is composed of back-to-back switching transistors connected in series.

3. The circuit according to claim 1, characterized in that, The inverter circuit includes a full-bridge inverter circuit or a half-bridge inverter circuit.

4. The circuit according to claim 1, characterized in that, The first capacitor includes a first sub-capacitor and a second sub-capacitor connected in parallel.

5. The circuit according to claim 1, characterized in that, The rectifier circuit includes at least one diode and / or at least one synchronous rectifier.

6. The circuit according to claim 1, characterized in that, The second inductor is integrated into the transformer in the rectifier circuit as the magnetizing inductor of the transformer; or, the second inductor is an inductor independent of the rectifier circuit.

7. The circuit according to claim 1, characterized in that, The two ends of the switch are also connected to a bidirectional transient voltage suppressor diode, which is used for voltage clamping.

8. The circuit according to claim 1, characterized in that, The circuit further includes a drive control circuit; the drive control circuit is connected to the switch and is used to output a control signal to the switch.

9. The circuit according to claim 8, characterized in that, The drive control circuit includes: A sampling circuit is used to sample the output voltage of the rectifier circuit and generate an output voltage sampling signal; A control circuit, electrically connected to the sampling circuit, generates a control signal based on the output voltage sampling signal; A drive circuit, connected to the control circuit and the switch, drives the switch to turn on or off according to the control signal.

10. The circuit according to claim 9, characterized in that, The drive circuit is also connected to the inverter circuit, and the drive circuit is also used to drive the switching transistor of the inverter circuit to turn on or off according to the control signal, so as to control the operating frequency of the inverter circuit.

11. A control method for a resonant converter circuit, characterized in that, The method includes: The output voltage of the resonant converter circuit according to any one of claims 1 to 10 is sampled to generate an output voltage sampling signal; A control signal is generated based on the output voltage sampling signal; The switch is turned on or off according to the control signal. Specifically, the switch is controlled to be turned on during a predetermined time period in each switching cycle. The predetermined time period is located in the later part of the positive and negative half-cycles. When the switch is turned on, the two ends of the second inductor are short-circuited to increase the energy of the first inductor and the first capacitor.

12. The method according to claim 11, characterized in that, The method further includes: driving the switching transistor of the inverter circuit to turn on or off according to the control signal, so as to control the operating frequency of the inverter circuit.

13. The method according to claim 12, characterized in that, The conduction time of the switch is controlled after the operating frequency reaches the preset frequency.

14. The method according to claim 11, characterized in that, Driving the switch to turn on or off according to the control signal includes: controlling the switch to turn on during a predetermined time period in each switching cycle to short-circuit the two ends of the second inductor.

15. The method according to claim 14, characterized in that, The switching period is greater than the resonant period of the first inductor and the first capacitor, and the predetermined time period is the later part of the positive and negative half-cycles of the switching period.

16. A power supply device, characterized in that, The resonant converter circuit includes any one of claims 1 to 10.

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