Phase-shifted full-bridge converter control method and apparatus, device, and storage medium

Abstract

A phase-shifted full-bridge converter control method and apparatus, a device, and a storage medium, relating to the technical field of converters. The method comprises: controlling a first switching transistor and a fourth switching transistor to be turned on for a first duration, so that an input direct-current source outputs a current to a phase-shifted full-bridge converter, a first resonant cavity stores energy, a first resonant capacitor is discharged, and a second resonant capacitor is charged; controlling the first switching transistor and the fourth switching transistor to remain turned on for a second duration, so that the input direct-current source outputs a current to an output direct-current source through the phase-shifted full-bridge converter; and controlling the first switching transistor to be turned off, and controlling a second switching transistor and the fourth switching transistor of the phase-shifted full-bridge converter to be turned on for a third duration, so that a second resonant cavity releases energy until the first resonant capacitor is discharged to the lowest resonant voltage and the second resonant capacitor is charged to the highest resonant voltage. According to embodiments of the present application, the input voltage range can be increased, solving the problem of conversion efficiency degradation of the phase-shifted full-bridge converter caused by increasing the turn ratio of the transformer.

Description

A control method, device and apparatus of a phase-shifted full-bridge converter, and a storage medium

[0001] The present application claims priority to the Chinese patent application No. 202410430339.9, filed on April 10, 2024, and entitled "A control method, device and apparatus of a phase-shifted full-bridge converter, and a storage medium", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of converters, and in particular to a control method, device and apparatus of a phase-shifted full-bridge converter, and a storage medium. BACKGROUND

[0003] The phase-shifted full-bridge converter is a soft-switching full-bridge topology, which uses the junction capacitance of the power device and the resonant inductance as resonant elements to realize zero-voltage turn-on and turn-off of the primary side switching tube of the full-bridge power supply, effectively improving the overall efficiency of the full-bridge power supply. The minimum value of the input voltage of the phase-shifted full-bridge converter is affected by the turns ratio of the transformer. In order to obtain a lower input voltage limit to ensure a wider working voltage, the turns ratio of the transformer will be increased, but this change significantly reduces the conversion efficiency of the phase-shifted full-bridge converter.

[0004] Therefore, how to increase the range of input voltage without reducing the conversion efficiency is a technical problem that needs to be solved by those skilled in the art at present.

[0005] SUMMARY

[0006] Therefore, how to increase the range of input voltage without reducing the conversion efficiency is a technical problem that needs to be solved by those skilled in the art at present.

[0007] In a first aspect, the present application provides a control method of a phase-shifted full-bridge converter, the phase-shifted full-bridge converter comprising a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a transformer, a first transistor, a second transistor, a first parallel capacitor, a second parallel capacitor, a first resonant capacitor and a second resonant capacitor; the first switching tube and the fourth switching tube are turned on at the initial state of each working cycle of the phase-shifted full-bridge converter, and the second switching tube and the third switching tube are turned off at the initial state of each working cycle of the phase-shifted full-bridge converter, and the method comprises:

[0008] controlling the first switch tube and the fourth switch tube to be turned on for a first time duration, so that the input direct current source outputs current to the phase-shifted full-bridge converter, and a first resonant cavity stores energy, the first resonant capacitor is discharged, and the second resonant capacitor is charged, the first resonant cavity including the leakage inductance of the transformer, the magnetizing inductance of the transformer, the first parallel capacitor, the second parallel capacitor, the first resonant capacitor, and the second resonant capacitor;

[0009] controlling the first switch tube and the fourth switch tube to continue to be turned on for a second time duration, so that the input direct current source outputs current to an output direct current source through the phase-shifted full-bridge converter, and the first parallel capacitor and the second parallel capacitor stop resonating;

[0010] controlling the first switch tube to be turned off, and controlling the second switch tube and the fourth switch tube to be turned on for a third time duration, so that a second resonant cavity releases energy until the first resonant capacitor is discharged to a resonant minimum voltage and the second resonant capacitor is charged to a resonant maximum voltage, the second resonant cavity including the leakage inductance, the magnetizing inductance, the first resonant capacitor, and the second resonant capacitor.

[0011] In a possible implementation, after the controlling the first switch tube to be turned off and the controlling the second switch tube and the fourth switch tube to be turned on for the third time duration, the method further includes:

[0012] controlling the fourth switch tube to be turned off, and controlling the second switch tube and the third switch tube to be turned on for a fourth time duration, so that the input direct current source outputs current to the phase-shifted full-bridge converter, and the first resonant cavity stores energy, the first resonant capacitor is charged, and the second resonant capacitor is discharged;

[0013] controlling the second switch tube and the third switch tube to continue to be turned on for a fifth time duration, so that the input direct current source outputs current to the output direct current source through the phase-shifted full-bridge converter, and the first parallel capacitor and the second parallel capacitor stop resonating;

[0014] controlling the second switch tube to be turned off, and controlling the first switch tube and the third switch tube to be turned on for a sixth time duration, so that the second resonant cavity releases energy until the first resonant capacitor is charged to the resonant maximum voltage and the second resonant capacitor is discharged to the resonant minimum voltage.

[0015] In a possible implementation, the method further includes:

[0016] determining a phase-shift time duration of the phase-shifted full-bridge converter based on the duty cycle and an effective on duration of the phase-shifted full-bridge converter.

[0017] In a possible implementation, the method further includes:

[0018] determine the effective turn-on duration of the phase-shifted full-bridge converter based on the input voltage of the phase-shifted full-bridge converter, the output voltage of the phase-shifted full-bridge converter, the inductance of the leakage inductance, the inductance of the magnetizing inductance, the turns ratio of the transformer, the capacitance of the first parallel capacitor, the capacitance of the second parallel capacitor, the capacitance of the first resonant capacitor, the capacitance of the second resonant capacitor, and the duty cycle.

[0019] In a possible implementation, the first switch tube, the second switch tube, the third switch tube, and the fourth switch tube are metal oxide semiconductor field effect tubes with body diodes and parasitic capacitances.

[0020] In a second aspect, the present application also provides a control device of a phase-shifted full-bridge converter, the phase-shifted full-bridge converter comprising a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a transformer, a first transistor, a second transistor, a first parallel capacitor, a second parallel capacitor, a first resonant capacitor, and a second resonant capacitor; the first switch tube and the fourth switch tube are turned on at the initial state of each working cycle of the phase-shifted full-bridge converter, and the second switch tube and the third switch tube are turned off at the initial state of each working cycle of the phase-shifted full-bridge converter; the device comprises:

[0021] a first control module configured to control the first switch tube and the fourth switch tube to be turned on for a first duration, so that an input direct current source outputs current to the phase-shifted full-bridge converter, a first resonant cavity stores energy, the first resonant capacitor is discharged, and the second resonant capacitor is charged, the first resonant cavity comprising the leakage inductance of the transformer, the magnetizing inductance of the transformer, the first parallel capacitor, the second parallel capacitor, the first resonant capacitor, and the second resonant capacitor;

[0022] a second control module configured to control the first switch tube and the fourth switch tube to continue to be turned on for a second duration, so that the input direct current source outputs current to an output direct current source through the phase-shifted full-bridge converter, and the first parallel capacitor and the second parallel capacitor stop resonating;

[0023] a third control module configured to control the first switch tube to be turned off and control the second switch tube and the fourth switch tube to be turned on for a third duration, so that a second resonant cavity releases energy until the first resonant capacitor is discharged to a resonant minimum voltage and the second resonant capacitor is charged to a resonant maximum voltage, the second resonant cavity comprising the leakage inductance, the magnetizing inductance, the first resonant capacitor, and the second resonant capacitor.

[0024] In a possible implementation, the device further comprises:

[0025] a fourth control module configured to control the fourth switch to be turned off, control the second switch and the third switch to be turned on for a fourth time duration, and enable the input DC source to output current to the phase-shifted full-bridge converter, the first resonant cavity to store energy, and the first resonant capacitor to be charged and the second resonant capacitor to be discharged;

[0026] a fifth control module configured to control the second switch and the third switch to continue to be turned on for a fifth time duration, and enable the input DC source to output current to the output DC source through the phase-shifted full-bridge converter, and the first parallel capacitor and the second parallel capacitor to stop resonating;

[0027] a sixth control module configured to control the second switch to be turned off, control the first switch and the third switch to be turned on for a sixth time duration, and enable the second resonant cavity to release energy until the first resonant capacitor is charged to the highest resonant voltage and the second resonant capacitor is discharged to the lowest resonant voltage.

[0028] In a possible implementation, the apparatus further includes:

[0029] a phase-shift time duration determination module configured to determine a phase-shift time duration of the phase-shifted full-bridge converter based on the duty cycle and an effective on time duration of the phase-shifted full-bridge converter.

[0030] In a third aspect, the present application provides a computer device, including a memory and a processor.

[0031] The memory is configured to store a computer program.

[0032] The processor is configured to execute the computer program in the memory to implement the method in the first aspect or any one of the implementation manners of the first aspect.

[0033] In a fourth aspect, the present application provides a computer readable storage medium storing instructions, which, when executed on a computer, cause the computer to perform the method in the first aspect or any one of the implementation manners of the first aspect.

[0034] In the embodiment of the present application, the first switch tube and the fourth switch tube are controlled to be turned on for a first time duration, so that the input DC source outputs current to the phase-shifted full-bridge converter, the first resonant cavity stores energy, the first resonant capacitor is discharged, and the second resonant capacitor is charged; the first switch tube and the fourth switch tube are controlled to be turned on for a second time duration, so that the input DC source outputs current to the output DC source through the phase-shifted full-bridge converter, and the first parallel capacitor and the second parallel capacitor stop resonating; the first switch tube is controlled to be turned off, and the second switch tube and the fourth switch tube of the phase-shifted full-bridge converter are controlled to be turned on for a third time duration, so that the second resonant cavity releases energy until the first resonant capacitor is discharged to the lowest resonant voltage and the second resonant capacitor is charged to the highest resonant voltage. In the embodiment of the present application, the resonant cavity including the first parallel capacitor and the second parallel capacitor is used to store energy, and the resonant cavity can also release energy when the first parallel capacitor and the second parallel capacitor stop resonating. When the resonant cavity releases energy, the input voltage is superimposed and the transformer is powered at the same time, so that the input voltage range is increased, the boost ratio of the phase-shifted full-bridge converter is improved, and the problem of reducing the conversion efficiency of the phase-shifted full-bridge converter due to increasing the turns ratio of the transformer is solved. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0036] FIG. 1 shows a circuit schematic diagram of an existing phase-shifted full-bridge converter according to an embodiment of the present application;

[0037] FIG. 2 shows a circuit schematic diagram of a phase-shifted full-bridge converter according to an embodiment of the present application;

[0038] FIG. 3 shows a flow chart of a control method of a phase-shifted full-bridge converter according to an embodiment of the present application;

[0039] FIG. 4 shows a current trend schematic diagram of a phase-shifted full-bridge converter in a first mode according to an embodiment of the present application;

[0040] FIG. 5 shows a current trend schematic diagram of a phase-shifted full-bridge converter in a second mode according to an embodiment of the present application;

[0041] FIG. 6 shows a current trend schematic diagram of a phase-shifted full-bridge converter in a third mode according to an embodiment of the present application;

[0042] FIG. 7 shows a main waveform schematic diagram of a phase-shifted full-bridge converter according to an embodiment of the present application;

[0043] Fig. 8 shows a structural schematic diagram of a control device of a phase-shifted full-bridge converter according to an embodiment of the present application. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and superiorities of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in connection with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some, but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall into the scope of the present application.

[0045] By the phase-shifted full-bridge technology, the transformer leakage inductance freewheeling, the body diode and the parasitic capacitor of the Metal Oxide Semiconductor Field Effect Transistor (MOSFET) can realize the zero voltage switch (ZVS) control of the leading bridge arm of the phase-shifted full-bridge converter, the transformer leakage inductance freewheeling can realize the zero current switch (ZCS) control of the lagging bridge arm of the phase-shifted full-bridge converter, and the natural turn-off of the transformer secondary side rectifier diode can realize the soft switch ZCS. When the secondary side rectifier diodes are all turned off, no current can pass through, at which time the phase-shifted full-bridge converter stops power conversion. However, the minimum value of the input voltage of the phase-shifted full-bridge converter will be affected by the transformer turns ratio, in order to ensure a wider working voltage, the transformer turns ratio is currently increased to obtain a lower input voltage, but this change significantly reduces the conversion efficiency of the phase-shifted full-bridge converter.

[0046] Therefore, the present application provides a control method of a phase-shifted full-bridge converter, which can realize the ability to reduce the minimum working voltage, increase the input voltage range, improve the boost ratio and conversion efficiency of the phase-shifted full-bridge converter topology.

[0047] The current phase-shifted full-bridge converter is shown in Fig. 1, Vg is the input DC source, Vm is the output DC source; Q1, Q2, Q3, Q4 four MOSFETs form a transformer primary side single-phase full-bridge circuit; Lr is the transformer primary side leakage inductance, the left side is the positive direction of voltage, Lm is the transformer primary side excitation inductance, the upper side of Lm is the positive direction of voltage, 1:n is the transformer primary side and secondary side turns ratio, the left side is the transformer primary side, and the right side is the transformer secondary side; D1, D2 are rectifier diodes; Cr1, Cr2 are resonance capacitors, and the upper side of the capacitor is the positive direction of voltage.

[0048] The phase-shifted full-bridge converter of the embodiment of the present application is obtained on the basis of Fig. 1 and is shown in Fig. 2. The phase-shifted full-bridge converter of the embodiment of the present application comprises an input DC source Vg, an output DC source Vm, a primary full-bridge circuit, a transformer, a first transistor D1, a second transistor D2, a first parallel capacitor Cd1, a second parallel capacitor Cd2, a first resonant capacitor Cr1 and a second resonant capacitor Cr2. The primary full-bridge circuit of the phase-shifted full-bridge converter is composed of a first switch Q1, a second switch Q2, a third switch Q3 and a fourth switch Q4. The switches are usually MOSFETs (also known as MOS tubes) with body diodes and parasitic capacitors. The first transistor D1 and the second transistor D2 can be rectifier diodes or other devices capable of achieving the same function, such as MOS tubes.

[0049] The phase-shifted full-bridge converter comprises a leading bridge arm and a lagging bridge arm. The leading bridge arm comprises the first switch Q1 and the second switch Q2, and the lagging bridge arm comprises the third switch Q3 and the fourth switch Q4.

[0050] The first output end of the primary full-bridge circuit is connected to the first end of the leakage inductance Lr of the transformer, the second end of the leakage inductance Lr is connected to the first end of the primary winding of the transformer, the second output end of the primary full-bridge circuit is connected to the second end of the primary winding of the transformer, and the magnetizing inductance Lm of the transformer is connected in parallel across the primary winding of the transformer. The first end of the secondary winding of the transformer is connected to the first end of the first resonant capacitor Cr1 and the first end of the second resonant capacitor Cr2, the second end of the first resonant capacitor Cr1 is connected to the cathode of the first transistor D1, the anode of the first transistor D1 is connected to the cathode of the second transistor D2, the second end of the secondary winding of the transformer is connected to the cathode of the second transistor D2, the anode of the second transistor D2 is connected to the second end of the second resonant capacitor Cr2, the first parallel capacitor Cd1 is connected in parallel across the first transistor D1, and the second parallel capacitor Cd2 is connected in parallel across the second transistor D2.

[0051] Please refer to Fig. 3, which shows a flow chart of the control method of the phase-shifted full-bridge converter according to the embodiment of the present application. The embodiment of the present application at least comprises the following steps:

[0052] S11, control the first switch Q1 and the fourth switch Q4 to be conductive for a first time length.

[0053] In the embodiment of the present application, the first switch Q1 and the fourth switch Q4 are conductive in the initial state of each working cycle of the phase-shifted full-bridge converter, and the second switch Q2 and the third switch Q3 are off in the initial state of each working cycle of the phase-shifted full-bridge converter.

[0054] In each working cycle, the first switch tube Q1 and the fourth switch tube Q4 are controlled to be turned on for a first time length, so that the input DC source Vg outputs current to the phase-shift full-bridge converter, the primary side current of the transformer increases, the first parallel capacitor Cd1 is charged, that is, the voltage of the first parallel capacitor Cd1 increases, the second parallel capacitor Cd2 is discharged, that is, the voltage of the second parallel capacitor Cd2 decreases, the first resonant capacitor Cr1 is discharged, that is, the voltage of the first resonant capacitor Cr1 decreases, and the second resonant capacitor Cr2 is charged, that is, the voltage of the second resonant capacitor Cr2 increases, until the voltage of the first parallel capacitor Cd1 is the output voltage Um and the voltage of the second parallel capacitor Cd2 is 0. In this process, the input DC source Vg and the phase-shift full-bridge converter do not output current to the output DC source Vm, the first transistor D1 is in an off state, and the drain inductance Lr, the magnetizing inductance Lm, the first parallel capacitor Cd1, the second parallel capacitor Cd2, the first resonant capacitor Cr1 and the second resonant capacitor Cr2 participate in resonance at the same time, and the first resonant cavity formed by the drain inductance Lr, the magnetizing inductance Lm, the first parallel capacitor Cd1, the second parallel capacitor Cd2, the first resonant capacitor Cr1 and the second resonant capacitor Cr2 stores energy.

[0055] In the first time length when the first switch tube Q1 and the fourth switch tube Q4 are turned on, the first transistor D1 and the second transistor D2 are both in an off state, until the second parallel capacitor Cd2 is discharged to the voltage of 0 and the second transistor D2 is turned on.

[0056] S12, the first switch tube Q1 and the fourth switch tube Q4 are controlled to continue to be turned on for a second time length.

[0057] After the first switch tube Q1 and the fourth switch tube Q4 are controlled to be turned on for the first time length, the first switch tube Q1 and the fourth switch tube Q4 are controlled to be turned on for the second time length, so that the input DC source Vg outputs current to the output DC source Vm through the phase-shift full-bridge converter. The first transistor D1 remains in an off state, the voltage of the first parallel capacitor Cd1 is the output voltage Um, the voltage of the second parallel capacitor Cd2 is 0, the second transistor D2 is in a turned-on state, the voltage of the first resonant capacitor Cr1 continues to decrease, and the voltage of the second resonant capacitor Cr2 continues to decrease. In this process, the first parallel capacitor Cd1 and the second parallel capacitor Cd2 stop resonating under the action of transistor voltage clamping, the drain inductance Lr, the magnetizing inductance Lm, the first resonant capacitor Cr1 and the second resonant capacitor Cr2 participate in resonance at the same time, and the second resonant cavity formed by the drain inductance Lr, the magnetizing inductance Lm, the first resonant capacitor Cr1 and the second resonant capacitor Cr2 stores energy and releases energy.

[0058] S13, the first switch tube Q1 is controlled to be turned off, and the second switch tube Q2 and the fourth switch tube Q4 are controlled to be turned on for a third time length.

[0059] After controlling the first switch tube Q1 and the fourth switch tube Q4 to be turned on for a second time length, the first switch tube Q1 is controlled to be turned off, the second switch tube Q2 is controlled to be turned on, and the second switch tube Q2 and the fourth switch tube Q4 are controlled to be turned on for a third time length, so that the second resonance cavity releases energy, the primary current of the transformer decreases, the voltage of the first resonance capacitor Cr1 continues to decrease, the voltage of the second resonance capacitor Cr2 continues to decrease, until the primary current of the transformer is 0, the first resonance capacitor Cr1 is discharged to the resonance minimum voltage, and the second resonance capacitor Cr2 is charged to the resonance maximum voltage. In this process, the input DC source Vg does not provide an input current to the phase-shift full-bridge converter, and the second resonance cavity provides a current to the phase-shift full-bridge converter. The first switch tube Q1 is turned off, and because the leakage inductance Lr current cannot be abruptly changed, the second switch tube Q2 is turned on at this time, and the second switch tube Q2 is turned on at zero voltage.

[0060] When the first resonance capacitor Cr1 is discharged to the resonance minimum voltage, and the second resonance capacitor Cr2 is charged to the resonance maximum voltage, the primary current of the transformer and the current of the second transistor D2 are both continuous to 0, so that the second transistor D2 enters an off state.

[0061] In the embodiment of the present application, the first switch tube and the fourth switch tube are controlled to be turned on for a first time length, so that the input DC source outputs a current to the phase-shift full-bridge converter, the first resonance cavity stores energy, the first resonance capacitor is discharged, and the second resonance capacitor is charged. The first switch tube and the fourth switch tube are controlled to be turned on for a second time length, so that the input DC source outputs a current to the output DC source through the phase-shift full-bridge converter, and the first parallel capacitor and the second parallel capacitor stop resonating. The first switch tube is controlled to be turned off, the second switch tube and the fourth switch tube of the phase-shift full-bridge converter are controlled to be turned on for a third time length, so that the second resonance cavity releases energy, until the first resonance capacitor is discharged to the resonance minimum voltage, and the second resonance capacitor is charged to the resonance maximum voltage. The embodiment of the present application utilizes the resonance cavity including the first parallel capacitor and the second parallel capacitor to store energy, and in the case that the first parallel capacitor and the second parallel capacitor stop resonating, the resonance cavity can also release energy, the resonance cavity superimposes an input voltage while supplying power to the transformer when releasing energy, can realize the ability to increase the input voltage range, improve the boost ratio of the phase-shift full-bridge converter, and solve the problem of reducing the conversion efficiency of the phase-shift full-bridge converter due to increasing the turns ratio of the transformer.

[0062] The above is an introduction to the upper half of the working cycle of each working cycle. Next, the lower half of the working cycle is introduced.

[0063] S21, the fourth switch tube Q4 is controlled to be turned off, and the second switch tube Q2 and the third switch tube Q3 are controlled to be turned on for a fourth time length.

[0064] After controlling the second switch Q2 and the fourth switch Q4 to be on for the third time duration, the fourth switch Q4 is controlled to be off, the third switch Q3 is controlled to be on, and the second switch Q2 and the third switch Q3 are controlled to be on for the fourth time duration, so that the input DC source Vg outputs current to the output DC source Vm through the phase-shifted full-bridge converter, the first parallel capacitor Cd1 is discharged, the second parallel capacitor Cd2 is charged, the first resonant capacitor Cr1 is charged, and the second resonant capacitor Cr2 is discharged until the voltage of the first parallel capacitor Cd1 is 0 and the voltage of the second parallel capacitor Cd2 is the output voltage Um. When the voltage of the first parallel capacitor Cd1 is 0, the first transistor D1 is in the on state. When the fourth switch Q4 is off, the fourth switch Q4 is zero-current off.

[0065] During the fourth time duration when the second switch Q2 and the third switch Q3 are on, the first transistor D1 and the second transistor D2 are both in the off state until the first parallel capacitor Cd1 is discharged to 0, and the first transistor D1 is on.

[0066] S22, continue to control the second switch Q2 and the third switch Q3 to be on for a fifth time duration.

[0067] After controlling the second switch Q2 and the third switch Q3 to be on for the fourth time duration, the second switch Q2 and the third switch Q3 are controlled to be on for a fifth time duration, so that the input DC source Vg outputs current to the output DC source Vm through the phase-shifted full-bridge converter, the first resonant capacitor Cr1 continues to be charged, and the second resonant capacitor Cr2 continues to be discharged. During this process, the first transistor D1 remains in the on state, the second transistor D2 remains in the off state, the first parallel capacitor Cd1 and the second parallel capacitor Cd2 stop resonating due to the voltage clamping of the transistor, the leakage inductance Lr, the magnetizing inductance Lm, the first resonant capacitor Cr1 and the second resonant capacitor Cr2 participate in the resonance at the same time, and the second resonant cavity formed by the leakage inductance Lr, the magnetizing inductance Lm, the first resonant capacitor Cr1 and the second resonant capacitor Cr2 stores energy and releases energy.

[0068] S23, control the second switch Q2 to be off, and control the first switch Q1 and the third switch Q3 to be on for a sixth time duration.

[0069] After controlling the second switch Q2 and the third switch Q3 to be on for the fifth time duration, the second switch Q2 is controlled to be off, the first switch Q1 is controlled to be on, and the first switch Q1 and the third switch Q3 are controlled to be on for the sixth time duration, so that the leakage inductance Lr of the transformer releases energy, the primary current of the transformer decreases, the first resonant capacitor Cr1 continues to be charged, and the second resonant capacitor Cr2 continues to be discharged until the primary current of the transformer is 0, the first resonant capacitor Cr1 is charged to the highest resonant voltage, and the second resonant capacitor Cr2 is discharged to the lowest resonant voltage.

[0070] When the first resonant capacitor Cr1 is charged to the resonant maximum voltage and the second resonant capacitor Cr2 is discharged to the resonant minimum voltage, the primary side current of the transformer and the current of the first transistor D1 are both continuous to 0, so that the first transistor D1 enters the off state.

[0071] The t0 moment-t6 moment is a working cycle of the phase-shifted full-bridge converter. In the following, the control method is described according to different modes in a working cycle.

[0072] Each working cycle T can contain 6 modes, which are the first mode (t0 moment-t1 moment), the second mode (t1 moment-t2 moment), the third mode (t2 moment-t3 moment), the fourth mode (t3 moment-t4 moment), the fifth mode (t4 moment-t5 moment), and the sixth mode (t5 moment-t6 moment).

[0073] At the t0 moment, the phase-shifted full-bridge converter completes commutation, and the first switch tube Q1 and the fourth switch tube Q4 are turned on.

[0074] In the t0-t1 stage, the primary side current of the transformer, from zero, flows through the first switch tube Q1, the leakage inductance Lr, the primary side coil of the transformer, and the fourth switch tube Q4 in the forward direction and continuously increases, and the current direction is shown in FIG. 4. The first transistor D1 enters the off state, the voltage of the first parallel capacitor Cd1 starts to increase from zero, the first parallel capacitor Cd1 is charged, the voltage of the second parallel capacitor Cd2 starts to decrease from the output voltage Um, and the second parallel capacitor Cd2 is discharged. The voltage of the first resonant capacitor Cr1 starts to decrease from the resonant maximum voltage, the first resonant capacitor Cr1 is discharged, and the voltage of the second resonant capacitor Cr2 starts to increase from the resonant minimum voltage, and the second resonant capacitor Cr2 is charged.

[0075] At the t1 moment, the voltage of the first parallel capacitor Cd1 is charged to the output voltage Um, the voltage of the second parallel capacitor Cd2 is discharged to 0, and the second transistor D2 is turned on.

[0076] In the first mode, the phase-shifted full-bridge converter does not output current to the output DC source Vm, and the leakage inductance Lr, the magnetizing inductance Lm, the first parallel capacitor Cd1, the second parallel capacitor Cd2, the first resonant capacitor Cr1, and the second resonant capacitor Cr2 participate in the resonance at the same time.

[0077] In the t1-t2 stage, the first switch Q1 and the fourth switch Q4 are turned on, the transformer primary current flows through the first switch Q1, the leakage inductance Lr, the transformer, and the fourth switch Q4 in the forward direction, and the current flow is shown in FIG. 5. The first transistor D1 remains in the off state, the voltage of the first parallel capacitor Cd1 is the output voltage Um, the voltage of the second parallel capacitor Cd2 is zero, and the second transistor D2 remains in the on state. The voltage of the first resonant capacitor Cr1 continuously decreases, the first resonant capacitor Cr1 is discharged, and the voltage of the second resonant capacitor Cr2 continuously increases, and the second resonant capacitor Cr2 is charged.

[0078] In the second mode, the input DC source Vg and the phase-shifted full-bridge converter output current to the output DC source Vm. Due to the voltage clamping effect of the transistor, the first parallel capacitor Cd1 and the second parallel capacitor Cd2 no longer participate in the resonance, and the leakage inductance Lr, the magnetizing inductance Lm, the first resonant capacitor Cr1, and the second resonant capacitor Cr2 simultaneously participate in the resonance.

[0079] At t2, the first switch Q1 is turned off, and the second switch Q2 is turned on with zero voltage. At this time, the second switch Q2 and the fourth switch Q4 are in the on state.

[0080] In the t2-t3 stage, the input DC source Vg does not input current to the phase-shifted full-bridge converter. During this period, the leakage inductance Lr continues to flow to provide current for the phase-shifted full-bridge converter. The transformer primary current flows through the leakage inductance Lr, the transformer, the fourth switch Q4, and the body diode of the second switch Q2 in the forward direction, and the current continuously decreases. The current flow is shown in FIG. 6. The first transistor D1 remains in the off state, the voltage of the first parallel capacitor Cd1 is the output voltage Um, the voltage of the second parallel capacitor Cd2 is zero, and the second transistor D2 remains in the on state. The voltage of the first resonant capacitor Cr1 continuously decreases, the first resonant capacitor Cr1 is discharged, and the voltage of the second resonant capacitor Cr2 continuously increases, and the second resonant capacitor Cr2 is charged.

[0081] At t3, the transformer primary current and the current of the second transistor D2 are 0, and the second transistor D2 is turned off. The first resonant capacitor Cr1 is discharged to the lowest resonant voltage, and the second resonant capacitor Cr2 is charged to the highest resonant voltage. At t3, the fourth switch Q4 is turned off with zero current, and the third switch Q3 is turned on. At this time, the second switch Q2 and the third switch Q3 are in the on state.

[0082] In the third mode, the phase-shifted full-bridge converter outputs current to the output DC source Vm, and the leakage inductance Lr, the magnetizing inductance Lm, the first resonant capacitor Cr1, and the second resonant capacitor Cr2 simultaneously participate in the resonance.

[0083] In the t3-t4 stage, the voltage of the first parallel capacitor Cd1 decreases from the output voltage Um, the first parallel capacitor Cd1 is discharged, the voltage of the second parallel capacitor Cd2 increases from zero, the second parallel capacitor Cd2 is charged, and the second transistor D2 enters the off state. The transformer primary current flows reversely and continuously increases, the voltage of the first resonance capacitor Cr1 increases from the resonance minimum voltage, the first resonance capacitor Cr1 is charged, and the voltage of the second resonance capacitor Cr2 decreases from the resonance maximum voltage, and the second resonance capacitor Cr2 is discharged.

[0084] At the t4 moment, the voltage of the first parallel capacitor Cd1 is discharged to 0, the first transistor D1 is turned on, and the voltage of the second parallel capacitor Cd2 is charged to the output voltage Um.

[0085] In the t4-t5 stage, the first transistor D1 remains in the on state, the voltage of the first parallel capacitor Cd1 is zero, the voltage of the second parallel capacitor Cd2 is the output voltage Um, and the second transistor D2 remains in the off state. The voltage of the first resonance capacitor Cr1 continuously increases, the first resonance capacitor Cr1 is charged, and the voltage of the second resonance capacitor Cr2 continuously decreases, and the second resonance capacitor Cr2 is discharged.

[0086] At the t5 moment, the first switch tube Q1 is turned on with zero voltage, and the second switch tube Q2 is turned off. At this time, the first switch tube Q1 and the third switch tube Q3 are in the on state.

[0087] In the t5-t6 stage, the transformer primary current flows reversely, and the current continuously decreases. The first transistor D1 remains in the on state, the voltage of the first parallel capacitor Cd1 is zero, the voltage of the second parallel capacitor Cd2 is the output voltage Um, and the second transistor D2 remains in the off state. The voltage of the first resonance capacitor Cr1 continuously increases, the first resonance capacitor Cr1 is charged, and the voltage of the second resonance capacitor Cr2 continuously decreases, and the second resonance capacitor Cr2 is discharged.

[0088] At the t6 moment, the transformer primary current and the current of the first transistor D1 are 0, and the first transistor D1 is turned off. The first resonance capacitor Cr1 is charged to the resonance maximum voltage, and the second resonance capacitor Cr2 is discharged to the resonance minimum voltage. At the t6 moment, the third switch tube Q3 is turned off with zero current, and the fourth switch tube Q4 is turned on. At this time, the first switch tube Q1 and the fourth switch tube Q4 are in the on state.

[0089] In the process of charging and discharging of the parallel capacitors Cd1 / Cd2 when both the first transistor D1 and the second transistor D2 are turned off, the phase-shifted full-bridge converter does not charge the output DC source Vm, and in this time period (t0-t1 stage), the input DC source Vg charges the leakage inductance Lr of the transformer to store energy, until the charging and discharging of the parallel capacitors Cd1 / Cd2 ends, the transistors complete commutation and start to supply power to the output DC source Vm. At this time, since the leakage inductance Lr current cannot be abruptly changed, an induced electromotive force is generated to maintain the original current, and the input DC source Vg is superimposed to supply power to the transformer at the same time, thereby realizing the ability to increase the input voltage range and improving the topology boost ratio.

[0090] Based on the above control method, the input current Iin can be obtained through the leakage inductance Lr of the resonant device of the phase-shifted full-bridge converter, the excitation inductance Lm, the first parallel capacitor Cd1, the second parallel capacitor Cd2, the first resonant capacitor Cr1, the second resonant capacitor Cr2, the transformer turn ratio n, the input voltage Ug and the output voltage Um, the working period T, and the effective on-time ton:

[0091] Iin=I1(Vg,Vm,Lr,Lm,n,Cd,Cr,T,ton)。

[0092] It should be noted that for a specific hardware structure, the leakage inductance Lr, the excitation inductance Lm, the first parallel capacitor Cd1, the second parallel capacitor Cd2, the first resonant capacitor Cr1, the second resonant capacitor Cr2, and the transformer turn ratio n are fixed values, so the above formula can be simplified as:

[0093] Iin=I2(Ug,Um,T,ton)。

[0094] Further, the input power Pin can be obtained by Pin=Iin*Ug.

[0095] Based on the above soft-switching ZCS control mode of the lagging bridge arm, the effective on-time ton (the time of the first mode and the second mode) can be derived, that is, the first time + the second time:

[0096] ton=ton1(Um / Ug,Lr,Lm,Cd,Cr,n,T)。

[0097] Similarly, for a specific hardware structure, the leakage inductance Lr, the excitation inductance Lm, the first parallel capacitor Cd1, the second parallel capacitor Cd2, the first resonant capacitor Cr1, the second resonant capacitor Cr2, and the transformer turn ratio n are fixed values, so the above formula can be simplified as:

[0098] ton=ton2(Um / Ug,T)。

[0099] The phase-shifted time tps (the time of the third mode) is:

[0100] tps = T / 2 - ton = tps(Um / Ug, T).

[0101] Therefore, the embodiment of the present application can further include the following steps:

[0102] Determine the phase shift duration tps based on the working cycle T and the effective on duration ton.

[0103] Determine the effective on duration ton based on the input voltage Ug, the output voltage Um, the inductance of the leakage inductance Lr, the inductance of the excitation inductance Lm, the turns ratio of the transformer, the capacitance of the first parallel capacitor Cd1, the capacitance of the second parallel capacitor Cd2, the capacitance of the first resonance capacitor Cr1, the capacitance of the second resonance capacitor Cr2, and the working cycle T.

[0104] Please refer to FIG. 7, which shows the waveform diagram of the voltage and / or current of each device of the phase-shifted full-bridge converter provided by the embodiment of the present application. In the embodiment of the present application, the capacitance of the first parallel capacitor Cd1 and the capacitance of the second parallel capacitor Cd2 can be the same, and the capacitance of the first resonance capacitor Cr1 and the capacitance of the second resonance capacitor Cr2 can be the same. The sum of the voltage value of the first resonance capacitor Cr1 and the voltage value of the second resonance capacitor Cr2 is always the output voltage Um, and the current of the first resonance capacitor Cr1 and the current of the second resonance capacitor Cr2 are always equal in size and opposite in direction. Since the first parallel capacitor Cd1 is in parallel with the first transistor D1, the voltage curve of the first parallel capacitor Cd1 and the voltage curve of the first transistor D1 are completely the same. Since the second parallel capacitor Cd2 is in parallel with the second transistor D2, the voltage curve of the second parallel capacitor Cd2 and the voltage curve of the second transistor D2 are completely the same. The output voltage value is constant as Um, and the output current varies with the mode.

[0105] The embodiment of the present application expands the input voltage range of the phase-shifted full-bridge converter, enabling the phase-shifted full-bridge converter to work with more DC power sources, such as more photovoltaic modules with different voltages, and also improves the boost ratio of the phase-shifted full-bridge converter, enabling the bus voltage of the phase-shifted full-bridge converter to be improved, making it more adaptable to different AC grid voltages, and also improving the efficiency of the phase-shifted full-bridge converter, enabling the power consumption of the phase-shifted full-bridge converter to be reduced and energy loss to be reduced.

[0106] Next, a control device of a phase-shifted full-bridge converter provided by the present application will be introduced. The control device of a phase-shifted full-bridge converter introduced below can be correspondingly referred to the control method of a phase-shifted full-bridge converter introduced above.

[0107] Please refer to Figure 8, which shows a structural schematic diagram of a control device of a phase-shift full-bridge converter provided in the present application, the phase-shift full-bridge converter comprising a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a transformer, a first transistor, a second transistor, a first parallel capacitor, a second parallel capacitor, a first resonant capacitor and a second resonant capacitor; the first switch tube and the fourth switch tube are turned on at the initial state of each working cycle of the phase-shift full-bridge converter, the second switch tube and the third switch tube are turned off at the initial state of each working cycle of the phase-shift full-bridge converter, and the device comprises:

[0108] a first control module 801 for controlling the first switch tube and the fourth switch tube to be turned on for a first time length, so that an input direct current source outputs current to the phase-shift full-bridge converter, a first resonant cavity stores energy, the first resonant capacitor is discharged, and the second resonant capacitor is charged, wherein the first resonant cavity comprises leakage inductance of the transformer, magnetizing inductance of the transformer, the first parallel capacitor, the second parallel capacitor, the first resonant capacitor and the second resonant capacitor;

[0109] a second control module 802 for controlling the first switch tube and the fourth switch tube to continue to be turned on for a second time length, so that the input direct current source outputs current to an output direct current source through the phase-shift full-bridge converter, and the first parallel capacitor and the second parallel capacitor stop resonating;

[0110] a third control module 803 for controlling the first switch tube to be turned off and controlling the second switch tube and the fourth switch tube to be turned on for a third time length, so that a second resonant cavity releases energy until the first resonant capacitor is discharged to a resonant minimum voltage and the second resonant capacitor is charged to a resonant maximum voltage, wherein the second resonant cavity comprises the leakage inductance, the magnetizing inductance, the first resonant capacitor and the second resonant capacitor.

[0111] In the embodiments of the present application, the device further comprises:

[0112] a fourth control module for controlling the fourth switch tube to be turned off and controlling the second switch tube and the third switch tube to be turned on for a fourth time length, so that the input direct current source outputs current to the phase-shift full-bridge converter, the first resonant cavity stores energy, the first resonant capacitor is charged, and the second resonant capacitor is discharged;

[0113] a fifth control module for controlling the second switch tube and the third switch tube to continue to be turned on for a fifth time length, so that the input direct current source outputs current to the output direct current source through the phase-shift full-bridge converter, and the first parallel capacitor and the second parallel capacitor stop resonating;

[0114] A sixth control module is configured to control the second switch tube to be turned off, and control the first switch tube and the third switch tube to be turned on for a sixth time length, so that the second resonant cavity releases energy until the first resonant capacitor is charged to the resonant maximum voltage and the second resonant capacitor is discharged to the resonant minimum voltage.

[0115] In the embodiments of the present application, the device further comprises:

[0116] A phase shift time length determination module is configured to determine a phase shift time length of the phase shift full-bridge converter based on the working cycle and an effective turn-on time length of the phase shift full-bridge converter.

[0117] In the embodiments of the present application, the device further comprises:

[0118] An effective turn-on time length determination module is configured to determine an effective turn-on time length of the phase shift full-bridge converter based on an input voltage of the phase shift full-bridge converter, an output voltage of the phase shift full-bridge converter, an inductance of the leakage inductor, an inductance of the excitation inductor, a turns ratio of the transformer, a capacitance of the first parallel capacitor, a capacitance of the second parallel capacitor, a capacitance of the first resonant capacitor, a capacitance of the second resonant capacitor, and the working cycle.

[0119] In the embodiments of the present application, the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are metal oxide semiconductor field effect tubes with body diodes and parasitic capacitances.

[0120] The embodiments of the present application further provide a computer device, which comprises a memory and a processor.

[0121] The memory is configured to store a computer program.

[0122] The processor is configured to execute the computer program in the memory, so as to implement the method in the above method embodiments.

[0123] The embodiments of the present application further provide a computer readable storage medium, which stores instructions, and when the instructions are executed on a computer, the computer executes the method in the above method embodiments.

[0124] In the embodiment of the present application, the first control module controls the first switch tube of the phase-shift full-bridge converter and the fourth switch tube of the phase-shift full-bridge converter to be turned on for a first time length, so that the input DC source outputs current to the phase-shift full-bridge converter, the first resonant cavity stores energy, the first resonant capacitor is discharged, and the second resonant capacitor is charged; the second control module controls the first switch tube and the fourth switch tube to continue to be turned on for a second time length, so that the input DC source outputs current to the output DC source through the phase-shift full-bridge converter, and the first parallel capacitor and the second parallel capacitor stop resonating; the third control module controls the first switch tube to be turned off and controls the second switch tube and the fourth switch tube of the phase-shift full-bridge converter to be turned on for a third time length, so that the second resonant cavity releases energy until the first resonant capacitor is discharged to the lowest resonant voltage and the second resonant capacitor is charged to the highest resonant voltage. The embodiment of the present application stores energy by using the resonant cavity including the first parallel capacitor and the second parallel capacitor, and can release energy by using the resonant cavity in the case that the first parallel capacitor and the second parallel capacitor stop resonating. The resonant cavity superimposes the input voltage when releasing energy and supplies power for the transformer, so that the input voltage range can be increased, the boost ratio of the phase-shift full-bridge converter can be improved, and the problem of reducing the conversion efficiency of the phase-shift full-bridge converter due to increasing the turns ratio of the transformer is solved.

[0125] It should be noted that the same or similar parts among various embodiments can be referred to each other. For the device embodiments and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the related parts can be referred to the part of the method embodiments.

[0126] For each of the foregoing embodiments, in order to simply describe, it is expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited to the action sequence described, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0127] Finally, it should be noted that, in this document, the term "only" is used simply to set off from one entity or action to another in order to avoid the use of the term "and" more than once in a single clause. Moreover, the terms "comprise", "comprises" or "comprising" or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article or apparatus. An element proceeded by "comprises a" does not, without further constraints, exclude the existence of additional identical elements in the process, method, article or apparatus that comprises the element.

[0128] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0129] The above description is only preferred embodiments of the present application. It should be noted that, for those skilled in the art, some improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A control method for a phase-shifted full-bridge converter, characterized in that: The phase-shifted full-bridge converter includes a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a transformer, a first transistor, a second transistor, a first parallel capacitor, a second parallel capacitor, a first resonant capacitor, and a second resonant capacitor; the first switching tube and the fourth switching tube are turned on in an initial state of each working cycle of the phase-shifted full-bridge converter, and the second switching tube and the third switching tube are turned off in an initial state of each working cycle of the phase-shifted full-bridge converter. The method includes: controlling the first switching tube and the fourth switching tube to be turned on for a first duration so that the input DC source outputs current to the phase-shifted full-bridge converter, the first resonant cavity stores energy, the first resonant capacitor is discharged, and the second resonant capacitor is charged, wherein the first resonant cavity includes the leakage inductance of the transformer, the magnetizing inductance of the transformer, the first shunt capacitor, the second shunt capacitor, the first resonant capacitor, and the second resonant capacitor; controlling the first switching tube and the fourth switching tube to continue to be turned on for a second time period, so that the input DC source outputs current to the output DC source through the phase-shifted full-bridge converter, and the first parallel capacitor and the second parallel capacitor stop resonating; The first switching tube is controlled to be turned off, and the second switching tube and the fourth switching tube are controlled to be turned on for a third time period, so that the second resonant cavity releases energy until the first resonant capacitor is discharged to a minimum resonant voltage and the second resonant capacitor is charged to a maximum resonant voltage, wherein the second resonant cavity includes the leakage inductance, the excitation inductance, the first resonant capacitor, and the second resonant capacitor.

2. The method according to claim 1, characterized in that After controlling the first switch tube to be turned off and controlling the second switch tube and the fourth switch tube to be turned on for a third time period, the method further includes: controlling the fourth switch tube to turn off, and controlling the second switch tube and the third switch tube to turn on for a fourth time period, so that the input DC source outputs current to the phase-shifted full-bridge converter, the first resonant cavity stores energy, the first resonant capacitor is charged, and the second resonant capacitor is discharged; The second switch tube and the third switch tube are controlled to continue to be turned on for a fifth time period, so that the input DC source outputs current to the output DC source through the phase-shifted full-bridge converter, and the first The parallel capacitor and the second parallel capacitor stop resonating; The second switch tube is controlled to be turned off, and the first switch tube and the third switch tube are controlled to be turned on for a sixth period of time, so that the second resonant cavity releases energy until the first resonant capacitor is charged to the highest resonant voltage and the second resonant capacitor is discharged to the lowest resonant voltage.

3. The method according to claim 1 or 2, characterized in that The method further comprises: The phase shift duration of the phase shift full-bridge converter is determined based on the duty cycle and the effective on-time of the phase shift full-bridge converter.

4. The method according to claim 1 or 2, characterized in that The method further comprises: The effective on-time of the phase-shifted full-bridge converter is determined based on the input voltage of the phase-shifted full-bridge converter, the output voltage of the phase-shifted full-bridge converter, the inductance of the leakage inductance, the inductance of the excitation inductance, the turns ratio of the transformer, the capacitance of the first parallel capacitor, the capacitance of the second parallel capacitor, the capacitance of the first resonant capacitor, the capacitance of the second resonant capacitor and the working cycle.

5. The method according to claim 1 or 2, characterized in that The first switching tube, the second switching tube, the third switching tube and the fourth switching tube are metal oxide semiconductor field effect tubes with body diodes and parasitic capacitors.

6. A control device for a phase-shifted full-bridge converter, characterized in that: The phase-shifted full-bridge converter includes a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a transformer, a first transistor, a second transistor, a first parallel capacitor, a second parallel capacitor, a first resonant capacitor, and a second resonant capacitor; the first switching tube and the fourth switching tube are turned on in an initial state of each working cycle of the phase-shifted full-bridge converter, and the second switching tube and the third switching tube are turned off in an initial state of each working cycle of the phase-shifted full-bridge converter. The device includes: a first control module, configured to control the first switching transistor and the fourth switching transistor to be turned on for a first duration, so that the input DC source outputs current to the phase-shifted full-bridge converter, the first resonant cavity stores energy, the first resonant capacitor is discharged, and the second resonant capacitor is charged, wherein the first resonant cavity includes the leakage inductance of the transformer, the magnetizing inductance of the transformer, the first shunt capacitor, the second shunt capacitor, the first resonant capacitor, and the second resonant capacitor; a second control module, configured to control the first switch tube and the fourth switch tube to continue to be turned on for a second time period, so that the input DC source outputs current to the output DC source through the phase-shifted full-bridge converter, and the first parallel capacitor and the second parallel capacitor stop resonating; a third control module, configured to control the first switch tube to turn off, and control the second switch tube and the fourth switch tube to turn on for a third duration, so that the second resonant cavity releases energy until the first resonant capacitor is discharged to a minimum resonant voltage and the second resonant capacitor is charged to a maximum resonant voltage, wherein the second resonant cavity includes the leakage inductance, the excitation inductance, the first resonant capacitor, and the second resonant capacitor.

7. The device according to claim 6, characterized in that The device further comprises: a fourth control module, configured to control the fourth switch tube to turn off, and control the second switch tube and the third switch tube to turn on for a fourth duration, so that the input DC source outputs current to the phase-shifted full-bridge converter, the first resonant cavity stores energy, the first resonant capacitor is charged, and the second resonant capacitor is discharged; a fifth control module, configured to control the second switching transistor and the third switching transistor to continue to be turned on for a fifth duration, so that the input DC source outputs current to the output DC source through the phase-shifted full-bridge converter, and the first parallel capacitor and the second parallel capacitor stop resonating; a sixth control module, configured to control the second switch tube to turn off, and control the first switch tube and the third switch tube to turn on for a sixth period of time, so that the second resonant cavity releases energy until the first resonant capacitor is charged to the maximum resonant voltage and the second resonant capacitor is discharged to the minimum resonant voltage.

8. The device according to claim 6 or 7, characterized in that The device further comprises: The phase-shift duration determining module is configured to determine the phase-shift duration of the phase-shift full-bridge converter based on the working cycle and the effective on-time of the phase-shift full-bridge converter.

9. A computer device, characterized in that: include: Memory and processor; The memory is used to store computer programs; The processor is configured to execute the computer program in the memory to implement the method according to any one of claims 1 to 5.

10. A computer-readable storage medium, characterized in that The device stores instructions which, when executed on a computer, cause the computer to execute the method according to any one of claims 1 to 5.

Images