Resonant converter start-up control method, resonant converter, apparatus, and storage medium

Abstract

The application relates to a resonant converter starting control method, a resonant converter, a device and a storage medium, wherein the method comprises the following steps: a resonant sampling circuit collects a signal of a resonant loop to obtain a resonant voltage signal; a control signal generation circuit performs signal amplification processing on the resonant voltage signal to generate a target control signal; a collector of a first triode is connected with an auxiliary power supply; an emitter of the first triode is connected with an output end of a switch tube driving circuit; a base of a second triode adjusts a collector current based on the target control signal; a base of the first triode adjusts a driving voltage output by the emitter of the first triode and acting on a gate of a switch tube of the resonant converter based on the collector current of the second triode and the auxiliary power supply, so as to control a current flowing through a source and a drain of the switch tube. According to the method, the driving voltage is fed back to the gate of the switch tube through two triodes, closed-loop regulation is formed on the starting current of the resonant converter, and the reliability of the resonant converter during starting is improved.

Description

Technical Field

[0001] This application relates to the field of switching power supply technology, and in particular to a resonant converter start-up control method, a resonant converter, a device, and a storage medium. Background Technology

[0002] The LLC resonant converter operates in open-loop mode at the resonant point, i.e., in DC-DC converter (DCX) mode. The gain of the resonant network is relatively small near the resonant point fr, and its influence with frequency variation is relatively small. When the quality factor Q is constant, the larger the ratio K of the magnetizing inductance Lm to the resonant inductance Lr, the flatter the gain variation near the resonant point fr.

[0003] When designing LLC, in order to operate in DCX mode, the ratio K of the magnetizing inductance Lm and the resonant inductance Lr is usually chosen to be large. This results in a small inductance of Lr and a large value of the resonant capacitor Cr. In this case, the power devices will be subjected to a large current surge when the resonant converter starts up, resulting in poor reliability and even tube failure. Summary of the Invention

[0004] To address the safe startup problem of open-loop resonant converters, this application provides a startup control method for resonant converters, a resonant converter, a device, and a storage medium.

[0005] In a first aspect, this application provides a resonant converter startup control method, the method comprising:

[0006] The resonant sampling circuit acquires the signal from the resonant circuit to obtain the resonant voltage signal;

[0007] The control signal generation circuit amplifies the resonant voltage signal to generate a target control signal; the target control signal is used to adjust the drive voltage output by the switching transistor drive circuit; the switching transistor drive circuit includes at least a first transistor and a second transistor, the collector of the first transistor is connected to the auxiliary power supply, and the emitter of the first transistor is connected to the output terminal of the switching transistor drive circuit.

[0008] The base of the second transistor adjusts the collector current of the second transistor based on the target control signal; the base of the first transistor adjusts the drive voltage output from the emitter of the first transistor based on the collector current of the second transistor and the auxiliary power supply. The drive voltage acts on the gate of the resonant converter switch. By adjusting the drive voltage, the current flowing through the source and drain of the switch is adjusted.

[0009] Optionally, the resonant sampling circuit includes a resonant cavity current acquisition unit and a resonant cavity current conversion unit. The resonant sampling circuit acquires the signal of the resonant circuit to obtain the resonant voltage signal, including:

[0010] The resonant cavity current acquisition unit acquires the current signal of the resonant circuit;

[0011] The resonant cavity current conversion unit performs current conversion on the current signal to obtain the resonant voltage signal;

[0012] Optionally, the control signal generation circuit includes at least a signal comparison circuit, and the control signal generation circuit amplifies the resonant voltage signal to generate a target control signal, including:

[0013] Obtain the reference voltage;

[0014] The reference voltage and the resonant voltage signal are input to the signal comparison circuit;

[0015] The reference voltage and the resonant voltage signal are compared to obtain a voltage comparison result;

[0016] Based on the voltage comparison result, the signal output from the output terminal of the signal comparison circuit is adjusted to obtain the target control signal;

[0017] Optionally, the target control signal includes a first target control signal and a second target control signal. The step of adjusting the signal output from the signal comparison circuit based on the voltage comparison result to obtain the target control signal includes:

[0018] When the voltage comparison result indicates that the resonant voltage signal is greater than the reference voltage, the signal output by the signal comparison circuit is adjusted to obtain a first target control signal. The first target control signal is used to control the driving voltage output by the switching transistor driving circuit to decrease.

[0019] When the voltage comparison result indicates that the resonant voltage signal is less than the reference voltage, the signal output by the signal comparison circuit is adjusted to obtain a second target control signal. The second target control signal is used to control the driving voltage output by the switching transistor driving circuit to increase.

[0020] Optionally, the driving voltage is applied to the gate of the resonant converter switch, and the current flowing through the source and drain of the switch is controlled by adjusting the on-resistance of the switch.

[0021] Secondly, this application provides a resonant converter, which includes at least a resonant circuit, a resonant sampling circuit, a control signal generation circuit, and a switching transistor driving circuit; the resonant circuit includes a magnetizing inductor, a resonant inductor, a resonant capacitor, and a switching transistor; the switching transistor driving circuit includes at least a first transistor and a second transistor, the collector of the first transistor is connected to an auxiliary power supply, and the emitter of the first transistor is connected to the output terminal of the switching transistor driving circuit;

[0022] The resonant sampling circuit is connected in series between the magnetizing inductor and the resonant capacitor to collect the resonant voltage signal of the resonant circuit. The sampling output terminal of the resonant sampling circuit is connected to the first input terminal of the control signal generation circuit.

[0023] The output terminal of the control signal generation circuit is connected to the input terminal of the switching transistor driving circuit. The control signal generation circuit is used to amplify the resonant voltage signal to generate a target control signal. The target control signal is used to adjust the driving voltage output by the switching transistor driving circuit.

[0024] The base of the second transistor is connected to the input terminal of the switching transistor driving circuit, the switching transistor is connected to the output terminal of the switching transistor driving circuit, and the collector of the second transistor is connected to the base of the first transistor. The base of the second transistor adjusts the collector current of the second transistor based on the target control signal. The base of the first transistor adjusts the driving voltage output from the emitter of the first transistor based on the collector current of the second transistor and the auxiliary power supply. The output terminal of the switching transistor driving circuit is connected to the gate of the switching transistor, and the current flowing through the source and drain of the switching transistor is adjusted by adjusting the driving voltage.

[0025] Optionally, the resonant sampling circuit includes a resonant cavity current acquisition unit and a resonant cavity current conversion unit;

[0026] The resonant cavity current acquisition unit is connected in series between the magnetizing inductor and the resonant capacitor; the sampling output terminal of the resonant cavity current acquisition unit is connected to the input terminal of the resonant cavity current conversion unit, and the output terminal of the resonant cavity current conversion unit is connected to the first input terminal of the control signal generation circuit.

[0027] The resonant cavity current acquisition unit includes any one of the following: current transformer, sampling resistor, Hall sensor, current sensor, current sampling chip, analog-to-digital converter, and operational amplifier;

[0028] Optionally, the resonant cavity current acquisition unit includes a current transformer; the resonant cavity current conversion unit includes a first diode and a conversion resistor;

[0029] The first terminal of the primary side of the current transformer is connected to the excitation inductor, and the second terminal of the primary side of the current transformer is connected to the first terminal of the resonant capacitor.

[0030] The first end of the secondary side of the current transformer is connected to the anode of the first diode, the second end of the secondary side of the current transformer is connected to the first end of the conversion resistor, the second end of the conversion resistor is connected to the cathode of the first diode, and the second end of the conversion resistor and the cathode of the first diode serve as the output end of the resonant cavity current conversion unit.

[0031] Optionally, the control signal generation circuit includes a signal comparison circuit and a protection unit;

[0032] The first terminal of the signal comparison circuit is connected to the output terminal of the resonant cavity current conversion unit, the second terminal of the signal comparison circuit is connected to the reference voltage, and the output terminal of the signal comparison circuit is connected to the input terminal of the switching transistor drive circuit.

[0033] The protection unit is connected in series between the second terminal of the signal comparison circuit and the output terminal of the signal comparison circuit;

[0034] The signal comparison circuit includes any one of the following: error amplifier, transistor, microcontroller, microcontroller unit, and digital signal processor;

[0035] Optionally, the signal comparison circuit includes an error amplifier; the protection unit includes a first capacitor and a first resistor;

[0036] The non-inverting input of the error amplifier is connected to the output of the resonant cavity current conversion unit, and the inverting input of the error amplifier is connected to the reference voltage, the first terminal of the first capacitor, and the first terminal of the first resistor; the output of the error amplifier is connected to the second terminal of the first capacitor and the second terminal of the first resistor; the output of the error amplifier, the second terminal of the first capacitor, and the second terminal of the first resistor together serve as the output of the control signal generation circuit.

[0037] Optionally, the switching transistor driving circuit further includes: a second resistor and a second diode;

[0038] The base of the second transistor serves as the input terminal of the switching transistor driving circuit and is connected to the output terminal of the control signal generation circuit.

[0039] The collector of the second transistor is connected to the base of the first transistor, the first end of the second resistor, and the cathode of the second diode;

[0040] The emitter of the second transistor is connected to the source of the switching transistor;

[0041] The collector of the first transistor is connected to the auxiliary power supply and the second terminal of the second resistor; the emitter of the first transistor is connected to the anode of the second diode, and the emitter of the first transistor and the anode of the second diode together serve as the output terminal of the switching transistor drive circuit.

[0042] Optionally, the switching transistor drive circuit further includes a second capacitor;

[0043] The first terminal of the second capacitor is connected to the auxiliary power supply, and the second terminal of the second capacitor is connected to the emitter of the second transistor.

[0044] Optionally, the switching transistor drive circuit further includes a third resistor;

[0045] The first end of the third resistor serves as the input terminal of the switching transistor driving circuit and is connected to the output terminal of the control signal generation circuit.

[0046] The second end of the third resistor is connected to the base of the second transistor;

[0047] Optionally, the switching transistor includes a first switching transistor and a second switching transistor;

[0048] The output terminal of the switching transistor driving circuit is connected to the gate of the first switching transistor, and / or the output terminal of the switching transistor driving circuit is connected to the gate of the second switching transistor.

[0049] Thirdly, this application provides a switching power supply, which includes the resonant converter described in any of the second aspects.

[0050] Fourthly, this application provides a resonant converter start-up control device, the device comprising:

[0051] The resonant circuit sampling module is used to acquire signals from the resonant circuit and obtain the resonant voltage signal.

[0052] A control signal generation module is used to amplify the resonant voltage signal to generate a target control signal; the target control signal is used to adjust the drive voltage output by the switching transistor drive circuit; the switching transistor drive circuit includes at least a first transistor and a second transistor, the collector of the first transistor is connected to an auxiliary power supply, and the emitter of the first transistor is connected to the output terminal of the switching transistor drive circuit;

[0053] A switching transistor driving module is used to adjust the collector current of the second transistor based on the target control signal at the base of the second transistor; and to adjust the driving voltage output from the emitter of the first transistor based on the collector current of the second transistor and the auxiliary power supply at the base of the first transistor. The driving voltage is applied to the gate of the resonant converter switching transistor, and the current flowing through the source and drain of the switching transistor is adjusted by adjusting the driving voltage.

[0054] Fifthly, this application provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0055] Memory, used to store computer programs;

[0056] When a processor executes a program stored in a memory, it implements the steps of the resonant converter startup control method according to any embodiment of the first aspect.

[0057] In a sixth aspect, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the resonant converter start-up control method as described in any embodiment of the first aspect.

[0058] The technical solutions provided in this application have the following advantages compared with the prior art:

[0059] The method provided in this application includes: a resonant sampling circuit acquiring a signal from a resonant circuit to obtain a resonant voltage signal; a control signal generation circuit amplifying the resonant voltage signal to generate a target control signal; the target control signal being used to adjust the drive voltage output by a switching transistor drive circuit; the switching transistor drive circuit including at least a first transistor and a second transistor, the collector of the first transistor being connected to an auxiliary power supply, and the emitter of the first transistor being connected to the output terminal of the switching transistor drive circuit; the base of the second transistor adjusting the collector current of the second transistor based on the target control signal; the base of the first transistor adjusting the drive voltage output by the emitter of the first transistor based on the collector current of the second transistor and the auxiliary power supply, the drive voltage acting on the gate of the resonant converter switching transistor, and adjusting the current flowing through the source and drain of the switching transistor by adjusting the drive voltage. This method, through the two transistors in the switching transistor drive circuit feeding the drive voltage back to the gate of the switching transistor, forms a closed-loop regulation of the startup current of the resonant converter, improving the reliability of the resonant converter during startup without affecting its performance. Attached Figure Description

[0060] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0061] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0062] Figure 1 A system architecture diagram of a resonant converter startup control method provided in one embodiment of this application;

[0063] Figure 2 This is a schematic diagram of the structure of a resonant converter provided in one embodiment of this application;

[0064] Figure 3 A schematic flowchart illustrating a resonant converter startup control method according to an embodiment of this application;

[0065] Figure 4 This is a schematic diagram of the structure of a resonant converter start-up control device provided in one embodiment of this application;

[0066] Figure 5 This is a schematic diagram of the structure of an electronic device provided in one embodiment of this application.

[0067] The attached figures are labeled as follows:

[0068] 101 - Resonant circuit; 102 - Resonant sampling circuit; 103 - Control signal generation circuit; 104 - Switching transistor driving circuit;

[0069] Lr - Resonant inductor; Lm - Magnetizing inductor; Cr - Resonant capacitor; Q1 - First transistor; Q2 - Second transistor; Q3 - First switching transistor; Q4 - Second switching transistor; CT1 - Current transformer; U1 - Error amplifier; Aux - Auxiliary power supply; C1 - First capacitor; C2 - Second capacitor; C3 - Third capacitor; Co - Output capacitor; D1 - First diode; D2 - Second diode; D3 - Third diode; D4 - Fourth diode; D5 - Fifth diode; D6 - Sixth diode; R1 - First resistor; R2 - Second resistor; R3 - Third resistor; R4 - Fourth resistor; Rs - Switching resistor. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0071] The first embodiment of this application provides a resonant converter, which can be as follows: Figure 1 The system architecture is shown. The resonant converter includes at least a resonant circuit 101, a resonant sampling circuit 102, a control signal generation circuit 103, and a switching transistor drive circuit 104. The resonant sampling circuit 102 acquires the signal from the resonant circuit 101 to obtain the resonant voltage signal. The control signal generation circuit 103 amplifies the resonant voltage signal to generate a target control signal. The target control signal is used to adjust the drive voltage output by the switching transistor drive circuit 104. By adjusting the drive voltage applied to the gate of the resonant converter switching transistor, the current flowing through the source and drain of the switching transistor can be adjusted.

[0072] In this embodiment, the power device is operated in the linear region during startup. The resonant sampling circuit 102 samples the signal, and the control signal generation circuit 103 adjusts the magnitude of the Vgs drive voltage of the LLC half-bridge switch, thereby adjusting the on-resistance Rdson of the switch. This forms a closed-loop adjustment of the current in the resonant cavity. When the startup current of the resonant converter exceeds the current safety threshold, the startup current can be adjusted in a closed loop, thereby avoiding the burnout of components due to excessive startup current and solving the problem of safe startup of the resonant converter.

[0073] In one specific embodiment, the resonant converter can be as follows: Figure 2 As shown, this includes a typical half-bridge DCX_LLC circuit. The resonant circuit 101 includes a magnetizing inductor Lm, a resonant inductor Lr, a resonant capacitor Cr, and a switching transistor. The switching transistor drive circuit 104 includes at least a first transistor Q1 and a second transistor Q2.

[0074] The connection relationships are as follows:

[0075] The collector of the first transistor Q1 is connected to the auxiliary power supply Aux, and the emitter of the first transistor Q1 is connected to the output terminal (i.e., Vgs) of the switching transistor drive circuit 104.

[0076] The resonant sampling circuit 102 is connected in series between the magnetizing inductor Lm and the resonant capacitor Cr to acquire the resonant voltage signal of the resonant circuit 101. The sampling output terminal of the resonant sampling circuit 102 is connected to the first input terminal of the control signal generation circuit 103. The output terminal of the control signal generation circuit 103 is connected to the input terminal of the switching transistor drive circuit 104. The control signal generation circuit 103 is used to amplify the resonant voltage signal and generate a target control signal. The target control signal is used to adjust the drive voltage output by the switching transistor drive circuit 104. The base of the second transistor Q2 adjusts the collector current of the second transistor Q2 based on the control signal. The base of the first transistor Q1 adjusts the drive voltage output by the emitter of the first transistor Q1 based on the collector current of the second transistor Q2 and the auxiliary power supply Aux. The output terminal of the switching transistor drive circuit 104 is connected to the gate of the switching transistor. By adjusting the drive voltage, the current flowing through the source and drain of the switching transistor is adjusted. The current flowing through the source and drain of the switching transistor can also be called the current of the resonant cavity.

[0077] This should be understandable. Figure 2 The two Vgs appearing in the text are connected to each other or can be understood as being at the same position, and the three A's are also at the same position.

[0078] It should be noted that the switching transistors may include a first switching transistor Q3 and a second switching transistor Q4. The output terminal Vgs of the switching transistor drive circuit 104 can be connected to the gate of the first switching transistor Q3, the gate of the second switching transistor Q4, or both the gates of the first switching transistor Q3 and the gate of the second switching transistor Q4, in order to control the current of the resonant cavity.

[0079] Of course, the switching transistor drive circuit 104 may also include: a second resistor R2 and a second diode D2.

[0080] In this circuit, the base of the second transistor Q2 serves as the input terminal of the switching transistor drive circuit 104 and is connected to the output terminal of the control signal generation circuit 103. The collector of the second transistor Q2 is connected to the base of the first transistor Q1, the first terminal of the second resistor R2, and the cathode of the second diode D2. The emitter of the second transistor Q2 is connected to the source of the switching transistor. The collector of the first transistor Q1 is connected to the auxiliary power supply Aux and the second terminal of the second resistor R2. The emitter of the first transistor Q1 is connected to the anode of the second diode D2. The emitter of the first transistor Q1 and the anode of the second diode D2 together serve as the output terminal of the switching transistor drive circuit 104.

[0081] In one embodiment, to improve the safety of the switching transistor driving circuit, the switching transistor driving circuit 104 may further include a second capacitor C2 and a third resistor R3.

[0082] The first terminal of the second capacitor C2 is connected to the auxiliary power supply Aux, and the second terminal of the second capacitor C2 is connected to the emitter of the second transistor Q2. The first terminal of the third resistor R3 serves as the input terminal of the switching transistor drive circuit 104 and is connected to the output terminal of the control signal generation circuit 103. The second terminal of the third resistor R3 is connected to the base of the second transistor Q2.

[0083] In one embodiment, the resonant sampling circuit 102 includes a resonant cavity current acquisition unit and a resonant cavity current conversion unit.

[0084] The resonant cavity current acquisition unit is connected in series between the magnetizing inductor Lm and the resonant capacitor Cr. The sampling output terminal of the resonant cavity current acquisition unit is connected to the input terminal of the resonant cavity current conversion unit, and the output terminal of the resonant cavity current conversion unit is connected to the first input terminal of the control signal generation circuit.

[0085] The specific form of the resonant cavity current acquisition unit is not limited; any device that can perform the current sampling function is acceptable. For example, it can be a current transformer, sampling resistor, Hall sensor, current sensor, current sampling chip, analog-to-digital converter (ADC), operational amplifier, etc.

[0086] Taking the resonant cavity current acquisition unit as an example of a current transformer, the connection relationship is explained. The resonant cavity current conversion unit may include a first diode D1 and a conversion resistor Rs.

[0087] The connection is as follows: the first terminal of the primary side of current transformer CT1 is connected to the excitation inductor Lm, the second terminal of the primary side of current transformer CT1 is connected to the first terminal of resonant capacitor Cr, the first terminal of the secondary side of current transformer CT1 is connected to the anode of the first diode D1, the second terminal of the secondary side of current transformer CT1 is connected to the first terminal of the switching resistor Rs, the second terminal of the switching resistor Rs is connected to the cathode of the first diode D1, and the second terminal of the switching resistor Rs and the cathode of the first diode D1 serve as the output terminals of the resonant cavity current conversion unit.

[0088] In this embodiment, there is no need to add an extra structure for the acquisition voltage. The current is sampled by the resonant cavity current acquisition unit, and then the resonant voltage signal is obtained by the resonant cavity current conversion unit, thereby reducing the complexity of the circuit.

[0089] In one embodiment, the control signal generation circuit 103 includes a signal comparison circuit and a protection unit. A first terminal of the signal comparison circuit is connected to the output terminal of the resonant cavity current conversion unit, a second terminal of the signal comparison circuit is connected to a reference voltage, and the output terminal of the signal comparison circuit is connected to the input terminal of the switching transistor drive circuit. The protection unit is connected in series between the second terminal and the output terminal of the signal comparison circuit.

[0090] The specific form of the signal comparison circuit is not limited, as long as it can complete the comparison and output of signals. For example, the signal comparison circuit can be an error amplifier, a transistor, a microcontroller, a microcontroller unit (MCU), a digital signal processor (DSP), or other devices.

[0091] Taking a signal comparison circuit as an example of an error amplifier, the connection relationship is explained. The protection unit may include a first capacitor C1 and a first resistor R1.

[0092] The connection is as follows: the non-inverting input of error amplifier U1 is connected to the output of the resonant cavity current conversion unit; the inverting input of error amplifier U1 is connected to the reference voltage Vref, the first terminal of the first capacitor C1, and the first terminal of the first resistor R1; the output of error amplifier U1 is connected to the second terminal of the first capacitor C1 and the second terminal of the first resistor R1; the output of error amplifier U1, the second terminal of the first capacitor C1, and the second terminal of the first resistor R1 together serve as the output of the control signal generation circuit, which can be connected to the base of Q2 through R3.

[0093] The reference voltage Vref can be determined based on the parameters of the components in the specific circuit structure, without any restrictions.

[0094] The specific control principles in the above embodiments are as follows:

[0095] The auxiliary power supply AUX is converted by Q1 to provide the Vgs drive voltage for Q3 (or Q4).

[0096] One end of R2 is connected to AUX, and the other end is connected to the base of Q1, providing the base bias current of Q1. The current transformer CT1 is a resonant cavity current sampling device, which is converted into a Vcs voltage signal after passing through D1 and Rs. The non-inverting input of the error amplifier U1 is connected to Vcs, and the inverting input is connected to the reference voltage Vref. The output is connected to the base of Q2 through a resistor R3. The collector of Q2 is connected to the base of Q1.

[0097] When the voltage at Vcs exceeds Vref, the output of error amplifier U1 increases, the current injected into the base of Q2 increases, the current flowing through the collector of Q2 increases, and since the current at R2 is relatively fixed, the current injected into the base of Q1 decreases, the voltage at Vgs decreases, the Rdson of the switching transistor increases, and the current flowing through Q3, i.e., the resonant cavity current, decreases.

[0098] When the Vcs voltage is lower than the Vref voltage, the output of the error amplifier U1 decreases, the current injected into the base of Q2 decreases, the current flowing through the collector of Q2 decreases, so the current injected into the base of Q1 increases, the Vgs voltage increases, the Rdson of the switching transistor decreases, and the current flowing through Q3, i.e., the resonant cavity current, increases.

[0099] In this embodiment, the resonant cavity current (i.e., the current flowing through the drain-source junction of Q1) is sampled by the current transformer CT1, and the magnitude of the Vgs voltage of Q3 is adjusted, thereby adjusting the magnitude of the resonant cavity current. This allows for closed-loop regulation of the resonant converter's starting current when it exceeds the current safety threshold, avoiding current surges caused by excessive starting current and thus preventing safety hazards such as component burnout. This solves the problem of safe starting of the resonant converter and improves the starting stability of the LLC resonant circuit. At the same time, the ratio K of the magnetizing inductance Lm to the resonant inductance Lr can be maintained at a relatively large parameter, allowing the resonant converter to operate in DC-DC converter DCX mode after startup, thereby improving the performance of the resonant converter.

[0100] Based on the same technical concept, the second embodiment of this application provides a resonant converter start-up control method, which can be applied to, for example... Figure 1 The system architecture shown or such Figure 2 The aforementioned resonant converter.

[0101] In this embodiment, a resonant converter startup control method is described, such as... Figure 3 The methods include:

[0102] Step 301: The resonant sampling circuit acquires the signal of the resonant circuit to obtain the resonant voltage signal.

[0103] In one embodiment, the resonant sampling circuit includes a resonant cavity current acquisition unit and a resonant cavity current conversion unit. The resonant sampling circuit acquires the signal of the resonant circuit to obtain a resonant voltage signal, including: the resonant cavity current acquisition unit acquires the current signal of the resonant circuit; the resonant cavity current conversion unit performs current conversion on the current signal to obtain a resonant voltage signal.

[0104] In this embodiment, the current signal of the resonant circuit can be acquired through a current transformer, sampling resistor, Hall sensor, current sensor, current sampling chip, analog-to-digital converter or operational amplifier, etc., without limitation. The resonant cavity current conversion unit can be composed of a diode and a conversion resistor, as described in the above embodiment. The specific connection method of the resonant cavity current conversion unit will not be repeated.

[0105] In this embodiment, no additional structure for acquiring voltage is required. The resonant voltage signal is obtained through current sampling and conversion circuit, thereby reducing the complexity of the circuit.

[0106] Step 302: The control signal generation circuit amplifies the resonant voltage signal to generate a target control signal. The target control signal is used to adjust the drive voltage output by the switching transistor drive circuit. The switching transistor drive circuit includes at least a first transistor and a second transistor. The collector of the first transistor is connected to the auxiliary power supply, and the emitter of the first transistor is connected to the output terminal of the switching transistor drive circuit.

[0107] In one embodiment, the control signal generation circuit includes at least a signal comparison circuit capable of performing signal comparison and output.

[0108] The control signal generation circuit amplifies the resonant voltage signal to generate the target control signal, including: acquiring a reference voltage; inputting the reference voltage and the resonant voltage signal into a signal comparison circuit; comparing the reference voltage and the resonant voltage signal to obtain a voltage comparison result; and adjusting the signal output from the signal comparison circuit based on the voltage comparison result to obtain the target control signal.

[0109] Specifically, the target control signal includes a first target control signal and a second target control signal. When the voltage comparison result indicates that the resonant voltage signal is greater than the reference voltage, the signal output from the signal comparison circuit is adjusted to obtain the first target control signal, which is used to control the driving voltage output by the switching transistor driving circuit to decrease. When the voltage comparison result indicates that the resonant voltage signal is less than the reference voltage, the signal output from the signal comparison circuit is adjusted to obtain the second target control signal, which is used to control the driving voltage output by the switching transistor driving circuit to increase.

[0110] In this embodiment, the signal comparison circuit can be an error amplifier, transistor, microcontroller, MCU, DSP, or other devices, without limitation.

[0111] In a more specific embodiment, when the function of the signal comparison circuit is implemented by the error amplifier, the control signal generation circuit amplifies the resonant voltage signal to generate a target control signal, including: acquiring a reference voltage, inputting the reference voltage into the inverting input terminal of the error amplifier, and inputting the resonant voltage signal into the non-inverting input terminal of the error amplifier; performing error amplification on the reference voltage and the resonant voltage signal to obtain the target control signal output by the output terminal of the error amplifier.

[0112] More specifically, the reference voltage and resonant voltage signals are subjected to error amplification processing to obtain a target control signal output from the error amplifier. This includes: when the resonant voltage signal is greater than the reference voltage, the reference voltage and resonant voltage signals are subjected to error amplification processing to obtain a first target control signal, which is used to control the driving voltage output by the switching transistor driving circuit to decrease; when the resonant voltage signal is less than the reference voltage, the reference voltage and resonant voltage signals are subjected to error amplification processing to obtain a second target control signal, which is used to control the driving voltage output by the switching transistor driving circuit to increase.

[0113] Step 303: The base of the second transistor adjusts the collector current of the second transistor based on the target control signal. The base of the first transistor adjusts the drive voltage output from the emitter of the first transistor based on the collector current of the second transistor and the auxiliary power supply. The drive voltage is applied to the gate of the resonant converter switching transistor. By adjusting the drive voltage, the current flowing through the source and drain of the switching transistor is adjusted.

[0114] In one embodiment, the driving voltage is applied to the gate of the resonant converter switch, and the current flowing through the source and drain of the switch is controlled by adjusting the on-resistance of the switch.

[0115] In this embodiment, the driving voltage is fed back to the gate of the switching transistor through two transistors in the switching transistor drive circuit, forming a closed-loop regulation of the start-up current of the resonant converter. This improves the reliability of the resonant converter during startup without affecting its performance. Simultaneously, the ratio K of the magnetizing inductance Lm to the resonant inductance Lr can be maintained at a relatively large parameter, allowing the resonant converter to operate in DC-DC converter DCX mode after startup, thus improving its performance.

[0116] Based on the same technical concept, the third embodiment of this application provides a switching power supply, which includes any of the resonant converters described in the first embodiment.

[0117] Based on the same technical concept, the fourth embodiment of this application provides a resonant converter start-up control device, such as... Figure 4 The device includes:

[0118] The resonant circuit sampling module 401 is used to acquire the signal of the resonant circuit and obtain the resonant voltage signal.

[0119] The control signal generation module 402 is used to amplify the resonant voltage signal to generate a target control signal; the target control signal is used to adjust the driving voltage output by the switching transistor driving circuit; the switching transistor driving circuit includes at least a first transistor and a second transistor, the collector of the first transistor is connected to the auxiliary power supply, and the emitter of the first transistor is connected to the output terminal of the switching transistor driving circuit;

[0120] The switching transistor driving module 403 is used to adjust the collector current of the second transistor based on the target control signal at the base of the second transistor; and to adjust the driving voltage output by the emitter of the first transistor based on the collector current of the second transistor and the auxiliary power supply at the base of the first transistor. The driving voltage is applied to the gate of the resonant converter switching transistor, and the current flowing through the source and drain of the switching transistor is adjusted by adjusting the driving voltage.

[0121] like Figure 5 As shown, the fifth embodiment of this application provides an electronic device, including a processor 111, a communication interface 112, a memory 113, and a communication bus 114, wherein the processor 111, the communication interface 112, and the memory 113 communicate with each other through the communication bus 114.

[0122] Memory 113 is used to store computer programs;

[0123] In one embodiment, when the processor 111 executes the program stored in the memory 113, it implements the resonant converter startup control method provided in any of the foregoing method embodiments, including:

[0124] The resonant sampling circuit acquires the signal from the resonant circuit to obtain the resonant voltage signal;

[0125] The control signal generation circuit amplifies the resonant voltage signal to generate a target control signal; the target control signal is used to adjust the drive voltage output by the switching transistor drive circuit; the switching transistor drive circuit includes at least a first transistor and a second transistor, the collector of the first transistor is connected to the auxiliary power supply, and the emitter of the first transistor is connected to the output terminal of the switching transistor drive circuit.

[0126] The base of the second transistor adjusts the collector current of the second transistor based on the target control signal; the base of the first transistor adjusts the drive voltage output from the emitter of the first transistor based on the collector current of the second transistor and the auxiliary power supply. The drive voltage acts on the gate of the resonant converter switch. By adjusting the drive voltage, the current flowing through the source and drain of the switch is adjusted.

[0127] The communication bus mentioned above can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the diagram, but this does not mean that there is only one bus or one type of bus.

[0128] The communication interface is used for communication between the aforementioned terminal and other devices.

[0129] The memory may include random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0130] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0131] The sixth embodiment of this application also provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the steps of the resonant converter start-up control method provided in any of the foregoing method embodiments.

[0132] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk (SSD)).

[0133] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0134] It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. In the description, suffixes such as "module," "part," or "unit" used to denote elements are used solely for illustrative purposes and have no specific meaning in themselves. Therefore, "module," "part," or "unit" may be used interchangeably.

[0135] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for starting up a resonant converter, characterized in that, The method includes: The resonant sampling circuit acquires the signal from the resonant circuit to obtain the resonant voltage signal; A control signal generation circuit amplifies the resonant voltage signal to generate a target control signal. This target control signal is used to adjust the drive voltage output by the switching transistor drive circuit. The switching transistor drive circuit includes at least a first transistor and a second transistor. The collector of the first transistor is connected to an auxiliary power supply, and the emitter of the first transistor is connected to the output terminal of the switching transistor drive circuit. The switching transistor drive circuit also includes a second resistor and a second diode. The base of the second transistor serves as the input terminal of the switching transistor drive circuit and is connected to the output terminal of the control signal generation circuit. The collector of the second transistor is connected to the base of the first transistor, the first terminal of the second resistor, and the cathode of the second diode. The emitter of the second transistor is connected to the source of the resonant converter's switching transistor. The collector of the first transistor is connected to the auxiliary power supply and the second terminal of the second resistor. The emitter of the first transistor is connected to the anode of the second diode, and the emitter of the first transistor and the anode of the second diode together serve as the output terminal of the switching transistor drive circuit. The base of the second transistor adjusts the collector current of the second transistor based on the target control signal; the base of the first transistor adjusts the drive voltage output from the emitter of the first transistor based on the collector current of the second transistor and the auxiliary power supply. The drive voltage acts on the gate of the switching transistor of the resonant converter. By adjusting the drive voltage, the current flowing through the source and drain of the switching transistor is adjusted.

2. The method according to claim 1, characterized in that, The resonant sampling circuit includes a resonant cavity current acquisition unit and a resonant cavity current conversion unit. The resonant sampling circuit acquires the signal of the resonant circuit to obtain the resonant voltage signal, including: The resonant cavity current acquisition unit acquires the current signal of the resonant circuit; The resonant cavity current conversion unit performs current conversion on the current signal to obtain the resonant voltage signal.

3. The method according to claim 1, characterized in that, The control signal generation circuit includes at least a signal comparison circuit. The control signal generation circuit amplifies the resonant voltage signal to generate a target control signal, including: Obtain the reference voltage; The reference voltage and the resonant voltage signal are input to the signal comparison circuit; The reference voltage and the resonant voltage signal are compared to obtain a voltage comparison result; Based on the voltage comparison result, the signal output from the signal comparison circuit is adjusted to obtain the target control signal.

4. The method according to claim 3, characterized in that, The target control signal includes a first target control signal and a second target control signal. The step of adjusting the signal output from the signal comparison circuit based on the voltage comparison result to obtain the target control signal includes: When the voltage comparison result indicates that the resonant voltage signal is greater than the reference voltage, the signal output by the signal comparison circuit is adjusted to obtain a first target control signal. The first target control signal is used to control the driving voltage output by the switching transistor driving circuit to decrease. When the voltage comparison result indicates that the resonant voltage signal is less than the reference voltage, the signal output from the output terminal of the signal comparison circuit is adjusted to obtain a second target control signal. The second target control signal is used to control the driving voltage output by the switching transistor driving circuit to increase.

5. The method according to claim 1, characterized in that, The driving voltage is applied to the gate of the switch transistor in the resonant converter, and the current flowing through the source and drain of the switch transistor is controlled by adjusting the on-resistance of the switch transistor.

6. A resonant converter start-up control device, characterized in that, The device includes: The resonant circuit sampling module is used to acquire signals from the resonant circuit and obtain the resonant voltage signal. A control signal generation module is used to amplify the resonant voltage signal to generate a target control signal. The target control signal is used to adjust the drive voltage output by the switching transistor drive circuit. The switching transistor drive circuit includes at least a first transistor and a second transistor. The collector of the first transistor is connected to an auxiliary power supply, and the emitter of the first transistor is connected to the output terminal of the switching transistor drive circuit. The switching transistor drive circuit also includes a second resistor and a second diode. The base of the second transistor serves as the input terminal of the switching transistor drive circuit and is connected to the output terminal of the control signal generation module. The collector of the second transistor is connected to the base of the first transistor, the first terminal of the second resistor, and the cathode of the second diode. The emitter of the second transistor is connected to the source of the switching transistor of the resonant converter. The collector of the first transistor is connected to the auxiliary power supply and the second terminal of the second resistor. The emitter of the first transistor is connected to the anode of the second diode, and the emitter of the first transistor and the anode of the second diode together serve as the output terminal of the switching transistor drive circuit. A switching transistor driving module is used to adjust the collector current of the second transistor based on the target control signal at the base of the second transistor; and to adjust the driving voltage output from the emitter of the first transistor based on the collector current of the second transistor and the auxiliary power supply at the base of the first transistor. The driving voltage is applied to the gate of the switching transistor of the resonant converter, and the current flowing through the source and drain of the switching transistor is adjusted by adjusting the driving voltage.

7. A resonant converter, characterized in that, The resonant converter includes at least a resonant circuit, a resonant sampling circuit, a control signal generation circuit, and a switching transistor driving circuit; the resonant circuit includes a magnetizing inductor, a resonant inductor, a resonant capacitor, and a switching transistor; the switching transistor driving circuit includes at least a first transistor and a second transistor, the collector of the first transistor is connected to an auxiliary power supply, and the emitter of the first transistor is connected to the output terminal of the switching transistor driving circuit. The switching transistor driving circuit further includes: a second resistor and a second diode; the base of the second transistor serves as the input terminal of the switching transistor driving circuit and is connected to the output terminal of the control signal generation circuit; the collector of the second transistor is connected to the base of the first transistor, the first terminal of the second resistor, and the cathode of the second diode; the emitter of the second transistor is connected to the source of the switching transistor of the resonant converter; the collector of the first transistor is connected to the auxiliary power supply and the second terminal of the second resistor; the emitter of the first transistor is connected to the anode of the second diode, and the emitter of the first transistor and the anode of the second diode together serve as the output terminal of the switching transistor driving circuit; The resonant sampling circuit is connected in series between the magnetizing inductor and the resonant capacitor to collect the resonant voltage signal of the resonant circuit. The sampling output terminal of the resonant sampling circuit is connected to the first input terminal of the control signal generation circuit. The output terminal of the control signal generation circuit is connected to the input terminal of the switching transistor driving circuit. The control signal generation circuit is used to amplify the resonant voltage signal to generate a target control signal. The target control signal is used to adjust the driving voltage output by the switching transistor driving circuit. The base of the second transistor adjusts the collector current of the second transistor based on the target control signal; the base of the first transistor adjusts the drive voltage output from the emitter of the first transistor based on the collector current of the second transistor and the auxiliary power supply; the output terminal of the switching transistor drive circuit is connected to the gate of the switching transistor, and the current flowing through the source and drain of the switching transistor is adjusted by adjusting the drive voltage.

8. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; When a processor executes a program stored in a memory, it implements the steps of the resonant converter start-up control method according to any one of claims 1-5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the resonant converter start-up control method as described in any one of claims 1-5.

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