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

Abstract

A phase-shifted full-bridge converter and a control method and apparatus therefor, and a medium, which relate to the field of electronic circuits. The control method comprises: when it is detected that the operating state of a phase-shifted full-bridge circuit meets a preset condition, determining a target turn-on time of each switch transistor on the basis of a power demand value and circuit element information; on the basis of the target turn-on times and a preset correspondence, determining a target duty ratio, and an output period of the phase-shifted full-bridge circuit; and on the basis of the output period and the target duty ratio, controlling the turn-on timing of the switch transistors. In the present application, when the operating state of a phase-shifted full-bridge circuit meets a preset condition, a target turn-on time of each switch transistor is determined on the basis of the correspondence between the turn-on time of each switch tube in a continuous current mode and the turn-on time of each switch tube in a discontinuous current mode, and a target duty ratio is determined on the basis of the correspondence between the duty ratio, the turn-on time and the output power of the circuit in the discontinuous current mode, thereby making the current of the circuit discontinuous, and thus reducing the switching loss of the circuit. Soft switching is realized by means of controlling the circuit to be in a resonant state within a turn-off time.

Description

A phase-shifted full-bridge converter and a control method, device and medium thereof

[0001] The present application claims priority to the Chinese patent application No. 202410426850.1, filed on April 10, 2024, and entitled "A phase-shifted full-bridge converter and a control method, device and medium thereof", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

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

[0003] The phase-shifted full-bridge converter is a common power electronic topology, which adjusts the driving voltage phase shift angle of the power tube on the bridge arm through phase-shift control technology to realize the regulation of the output voltage. This converter has high efficiency, low loss and good reliability, and is widely used in power inverters, power supplies and electric vehicle charging applications.

[0004] FIG. 1 is a structure diagram of an existing phase-shifted full-bridge circuit provided by an embodiment of the present application, as shown in FIG. 1, during the operation of the phase-shifted full-bridge converter, the switching tubes Q1-Q4 are alternately turned on. When the phase-shifted full-bridge converter is in a low-power output state, in order to reduce power consumption, the on-time of the switching tube needs to be reduced (i.e., the duty cycle is reduced), which results in a too high switching frequency of the switching tube, causing a too large switching loss of the circuit, affecting the stability of the circuit.

[0005] Therefore, how to provide a new phase-shifted full-bridge converter to prevent a too large switching loss when the phase-shifted full-bridge converter is in a low-power output state and improve the stability and output power of the phase-shifted full-bridge converter is a problem that needs to be solved by those skilled in the art.

[0006] SUMMARY

[0007] In order to solve the problem that the switching frequency of the switching tube is too high when the phase-shifted full-bridge converter is in a low-power output state in the prior art, the present application provides a phase-shifted full-bridge converter and a control method, device and medium thereof, which reduce the switching loss on the basis of ensuring the output power of the circuit.

[0008] In order to solve the above technical problem, the present application provides a phase-shifted full-bridge converter, comprising:

[0009] a controller, a phase-shifted full-bridge circuit and first and second capacitors;

[0010] The phase-shifted full-bridge circuit comprises a first bridge arm circuit, a second bridge arm circuit, an excitation inductor, a transformer, a first diode, a second diode, a third capacitor, and a fourth capacitor; wherein the first end of the excitation inductor is connected to the midpoint of the first bridge arm circuit, the second end of the excitation inductor is connected to the first end of the primary side of the transformer, and the second end of the primary side of the transformer is connected to the midpoint of the second bridge arm circuit; the first end of the secondary side of the transformer is connected to the second end of the third capacitor and the first end of the fourth capacitor, and the second end of the secondary side of the transformer is connected to the anode of the first diode and the cathode of the second diode; the cathode of the first diode and the first end of the third capacitor are commonly connected as a first output end, and the anode of the second diode and the second end of the fourth capacitor are commonly connected as a second output end.

[0011] The first capacitor is connected in parallel with the first diode of the secondary side of the phase-shifted full-bridge circuit, and the second capacitor is connected in parallel with the second diode of the secondary side of the phase-shifted full-bridge circuit.

[0012] The controller is connected to the control end of each switch tube of the phase-shifted full-bridge circuit.

[0013] To solve the above technical problems, the application further provides a phase-shifted full-bridge converter control method applied to a phase-shifted full-bridge converter, and the control method comprises the following steps:

[0014] When it is detected that the working state of the phase-shifted full-bridge circuit meets a preset condition, the target turn-on time of each switch tube of the phase-shifted full-bridge circuit is determined according to the power demand value and the circuit element information;

[0015] The target duty cycle and the output period of the phase-shifted full-bridge circuit are determined according to the target turn-on time and a preset corresponding relationship; wherein the preset corresponding relationship is the corresponding relationship among the duty cycle, the turn-on time, and the circuit output power in the current discontinuous mode;

[0016] The conduction timing of the switch tube of the phase-shifted full-bridge circuit is controlled according to the output period and the target duty cycle, so that the first capacitor, the second capacitor, the third capacitor, the fourth capacitor, and the transformer of the phase-shifted full-bridge circuit are in a resonant state within the turn-off time of the phase-shifted full-bridge circuit.

[0017] In some embodiments, determining whether the working state of the phase-shifted full-bridge circuit meets the preset condition comprises:

[0018] The real-time switching frequency of the switch tube of the phase-shifted full-bridge circuit and the power demand value of the phase-shifted full-bridge circuit are obtained;

[0019] When the real-time switching frequency is greater than the limit switching frequency and / or the power demand value is lower than a preset power, it is determined that the working state of the phase-shifted full-bridge circuit does not meet the preset condition; wherein the limit switching frequency is a value determined according to the corresponding relationship between the switching frequency and the switching loss of each switch tube in the phase-shifted full-bridge circuit.

[0020] In some embodiments, determining the target turn-on time of each switch tube of the phase-shifted full-bridge circuit according to the power demand value and the circuit element information comprises:

[0021] determining the performance information of the switch tube according to the circuit element information;

[0022] determining the preset frequency and the target turn-on time that make the output power of the phase-shifted full-bridge circuit meet the demand and the switching loss of the switch tube be minimum according to the performance information, the power demand value and the corresponding relationship between the switching loss of the switch tube and the circuit output power.

[0023] In some embodiments, determining the target duty cycle and the output period of the phase-shifted full-bridge circuit according to the target turn-on time and the preset corresponding relationship comprises:

[0024] obtaining the corresponding relationship between the turn-on time of the switch tube, the duty cycle and the circuit output power in the current discontinuous mode;

[0025] determining the target duty cycle and the output period of the phase-shifted full-bridge circuit according to the target turn-on time and the corresponding relationship.

[0026] In some embodiments, during the turn-off time, controlling the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer to be in the resonance state comprises:

[0027] in the first resonance period, controlling the second switch tube and the fourth switch tube of the phase-shifted full-bridge circuit to be conductive and the first switch tube and the third switch tube to be non-conductive, so as to control the first capacitor, the second capacitor and the transformer, the third capacitor and the fourth capacitor to be in the resonance state;

[0028] in the second resonance period, controlling the second switch tube and the fourth switch tube of the phase-shifted full-bridge circuit to be non-conductive and the first switch tube and the third switch tube to be conductive, so as to control the first capacitor, the second capacitor and the transformer, the third capacitor and the fourth capacitor to be in the resonance state;

[0029] after the step of controlling the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer, the third capacitor and the fourth capacitor to be in the resonance state, further comprising:

[0030] determining the number of resonance periods according to the turn-off time to determine the time of the resonance state.

[0031] In some embodiments, further comprising:

[0032] when the power demand value meets the preset condition, controlling the phase-shifted full-bridge circuit to be in the current continuous mode.

[0033] To solve the above technical problems, the application also provides a phase-shifted full-bridge converter control device applied to a phase-shifted full-bridge converter, the control device comprising:

[0034] The first determining module is configured to determine a target turn-on time of each switch tube of the phase-shifted full-bridge circuit according to the power demand value and the circuit element information when it is detected that the working state of the phase-shifted full-bridge circuit meets the preset condition.

[0035] The second determining module is configured to determine a target duty cycle and an output period of the phase-shifted full-bridge circuit according to the target turn-on time and a preset corresponding relationship; the preset corresponding relationship is a corresponding relationship among the duty cycle, the turn-on time and the circuit output power in the current discontinuous mode.

[0036] The control module is configured to control the turn-on sequence of the switch tube of the phase-shifted full-bridge circuit according to the output period and the target duty cycle, so that the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer of the phase-shifted full-bridge circuit are in a resonant state within the turn-off time of the phase-shifted full-bridge circuit.

[0037] To solve the above technical problems, the present application further provides a phase-shifted full-bridge converter control device, which comprises a memory for storing a computer program and a processor for executing steps of a phase-shifted full-bridge converter control method realized by the computer program.

[0038] To solve the above technical problems, the present application further provides a computer readable storage medium, which stores a computer program, and steps of a phase-shifted full-bridge converter control method realized by the computer program executed by a processor.

[0039] The application provides a phase-shift full-bridge converter control method, comprising: when it is detected that the working state of a phase-shift full-bridge circuit meets a preset condition, determining the target turn-on time of each switch tube of the phase-shift full-bridge circuit according to a power demand value and circuit element information, so as to increase the turn-on time of the switch tube while ensuring that the output power of the phase-shift full-bridge circuit is unchanged, thereby reducing the switching frequency of the switch tube; determining the target duty cycle and the output period of the phase-shift full-bridge circuit according to the target turn-on time and a preset corresponding relationship; wherein the preset corresponding relationship is the corresponding relationship among the duty cycle, the turn-on time and the circuit output power in the current discontinuous mode; and controlling the conduction timing of the switch tube of the phase-shift full-bridge circuit according to the output period and the target duty cycle, so as to make the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer of the phase-shift full-bridge circuit be in a resonant state within the turn-off time of the phase-shift full-bridge circuit. As can be seen, in the technical solution provided by the application, when the working state of the phase-shift full-bridge circuit meets the preset condition, the target turn-on time of the switch tube is determined according to the corresponding relationship between the turn-on time of the switch tube in the current continuous mode and the current discontinuous mode, and the target duty cycle is determined according to the corresponding relationship among the duty cycle, the turn-on time and the circuit output power in the current discontinuous mode, so as to make the phase-shift full-bridge circuit enter the current discontinuous mode, thereby reducing the switching loss of the switch tube. Further, by controlling the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer of the phase-shift full-bridge circuit to be in the resonant state within the turn-off time of the phase-shift full-bridge circuit, the soft switching of the circuit is realized, thereby further reducing the switching loss.

[0040] In addition, the application also provides a phase-shift full-bridge circuit control method, device and medium, and the effects are the same as above. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the application, the drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0042] FIG. 1 is a structure diagram of an existing phase-shift full-bridge circuit provided by an embodiment of the application;

[0043] FIG. 2 is a structure diagram of a phase-shift full-bridge converter provided by an embodiment of the application;

[0044] FIG. 3 is a flow chart of a phase-shift full-bridge converter control method provided by an embodiment of the application;

[0045] FIG. 4 is a schematic diagram of a phase-shift full-bridge converter mode one provided by an embodiment of the application;

[0046] FIG. 5 is a schematic diagram of a phase-shift full-bridge converter mode two provided by an embodiment of the application;

[0047] Fig. 6 is a schematic diagram of a phase-shifted full-bridge converter mode three provided by an embodiment of the present application;

[0048] Fig. 7 is a main waveform diagram of the mode in the current continuous mode of the present application;

[0049] Fig. 8 is a schematic diagram of a phase-shifted full-bridge converter mode four one provided by an embodiment of the present application;

[0050] Fig. 9 is a schematic diagram of a phase-shifted full-bridge converter mode four two provided by an embodiment of the present application;

[0051] Fig. 10 is a main waveform diagram of the mode in the current discontinuous mode of the present application;

[0052] Fig. 11 is another waveform diagram of the mode in the current discontinuous mode of the present application;

[0053] Fig. 12 is a structural diagram of a phase-shifted full-bridge converter control device provided by an embodiment of the present application;

[0054] Fig. 13 is a structural diagram of another phase-shifted full-bridge converter control device provided by an embodiment of the present application;

[0055] Reference signs:

[0056] 1 - controller; 2 - phase-shifted full-bridge circuit. DETAILED DESCRIPTION

[0057] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0058] The core of the present application is to provide a phase-shifted full-bridge converter and a control method, device and medium thereof, to reduce the switching loss of the circuit and realize soft switching of the circuit.

[0059] Figure 1 is a structure diagram of a prior phase-shifted full-bridge circuit provided by an embodiment of the present application. As shown in Figure 1, in the phase-shifted full-bridge circuit 2, when the circuit is in a low-power output state, in order to reduce power consumption, the on-time of the switch tube needs to be reduced (i.e. the duty cycle is reduced), which results in that the switching frequency of the switch tube is too high and the switching loss of the circuit is too large, which affects the stability of the circuit. In order to solve this technical problem, the present application provides a phase-shifted full-bridge converter and a control method thereof. When the working state of the phase-shifted full-bridge circuit meets a preset condition, the target on-time of the switch tube is determined according to the corresponding relationship between the on-time of the switch tube in the continuous current mode and the discontinuous current mode, and the target duty cycle is determined according to the corresponding relationship between the duty cycle, the on-time and the output power of the circuit in the discontinuous current mode, so that the phase-shifted full-bridge circuit enters the discontinuous current mode, thereby reducing the switching loss of the switch tube. Further, by controlling the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer of the phase-shifted full-bridge circuit to be in a resonant state within the off-time of the phase-shifted full-bridge circuit, the soft switching of the circuit is realized, thereby further reducing the switching loss.

[0060] In order for those skilled in the art to better understand the scheme of the present application, the present application will be further described in detail below in combination with the drawings and specific embodiments.

[0061] Figure 2 is a structure diagram of a phase-shifted full-bridge converter provided by an embodiment of the present application. As shown in Figure 2, the phase-shifted full-bridge converter comprises a controller 1, a phase-shifted full-bridge circuit 2 and a first capacitor Cd1 and a second capacitor Cd2. The phase-shifted full-bridge circuit 2 comprises a first bridge arm circuit, a second bridge arm circuit, an inductor, a transformer and a first diode D1, a second diode D2, a third capacitor Cr1 and a fourth capacitor Cr2. The first end of the inductor is connected to the midpoint of the first bridge arm circuit, the second end of the inductor is connected to the first end of the primary side of the transformer, and the second end of the primary side of the transformer is connected to the midpoint of the second bridge arm circuit. The first end of the secondary side of the transformer is connected to the second end of the third capacitor Cr1 and the first end of the fourth capacitor Cr2, and the second end of the secondary side of the transformer is connected to the anode of the first diode D1 and the cathode of the second diode D2. The cathode of the first diode D1 and the first end of the third capacitor Cr1 are commonly connected as a first output end, and the anode of the second diode D2 and the second end of the fourth capacitor Cr2 are commonly connected as a second output end. The first capacitor Cd1 is connected in parallel with the first diode D1 of the secondary side of the phase-shifted full-bridge circuit 2, and the second capacitor Cd2 is connected in parallel with the second diode D2 of the secondary side of the phase-shifted full-bridge circuit 2. The controller 1 is connected to the control end of each switch tube of the phase-shifted full-bridge circuit 2.

[0062] In the embodiment, when the phase-shifted full-bridge circuit 2 is in the low-power output state, the controller 1 controls the on-off timing of the switch tubes to make the circuit enter the current discontinuous mode, thereby reducing the switching frequency of the switch tubes and lowering the switching loss. When the phase-shifted full-bridge circuit 2 is in the high-power output state, the controller 1 controls the on-off timing of the switch tubes to make the circuit enter the current continuous mode, thereby ensuring the stable output of the phase-shifted full-bridge circuit 2. The high power and the low power are values determined according to the element information of the circuit, which are not limited here.

[0063] In the embodiment, in order to reduce the switching frequency of the switch tubes, the on time of the switch tubes needs to be increased, i.e., the low-level output time in each output period of the phase-shifted full-bridge circuit 2 needs to be increased. After the low-level output time is increased, in order to ensure the output power (ensure the duty cycle), the high-level output time is increased, and the overall period is also increased.

[0064] The embodiment provides a phase-shifted full-bridge converter, which comprises a controller, a phase-shifted full-bridge circuit, and a first capacitor and a second capacitor. The first capacitor is connected in parallel with a first diode on the secondary side of the phase-shifted full-bridge circuit, and the second capacitor is connected in parallel with a second diode on the secondary side of the phase-shifted full-bridge circuit. The controller is configured to, when detecting that a power demand value does not satisfy a preset condition, determine an output duty cycle according to the power demand value, determine an off time of the phase-shifted full-bridge circuit according to the element information of the circuit, and determine an output period of the phase-shifted full-bridge circuit according to the duty cycle and the off time, so as to ensure that the output power of the phase-shifted full-bridge circuit meets the power demand value. The controller is further configured to control the on-off timing of the switch tubes of the phase-shifted full-bridge circuit according to the output period, so that the phase-shifted full-bridge circuit enters the current discontinuous mode. The off time is a value that makes the switching frequency of each switch tube not greater than a preset frequency, and the preset frequency is a value determined according to the corresponding relationship between the switching loss of the switch tube and the output power of the circuit. The controller 1 is further configured to control the first capacitor, the second capacitor, a third capacitor, a fourth capacitor, and a transformer to be in a resonant state within the off time of the phase-shifted full-bridge converter, so as to realize soft switching of the circuit after the off time of the phase-shifted full-bridge converter ends, and further reduce the switching loss. It can be seen that, in the technical solution provided in the embodiment, when the working state of the phase-shifted full-bridge circuit meets the preset condition, the target on time of the switch tube is determined according to the corresponding relationship between the on time of the switch tube in the current continuous mode and the current discontinuous mode, and the target duty cycle is determined according to the corresponding relationship between the on time and the output power of the circuit in the current discontinuous mode, so that the phase-shifted full-bridge circuit enters the current discontinuous mode, thereby reducing the switching loss of the switch tube. Further, by controlling the first capacitor, the second capacitor, the third capacitor, the fourth capacitor, and the transformer of the phase-shifted full-bridge circuit to be in the resonant state within the off time of the phase-shifted full-bridge circuit, the soft switching of the circuit is realized, thereby further reducing the switching loss.

[0065] Fig. 3 is a flow chart of a control method of a phase-shifted full-bridge converter provided by an embodiment of the present application, the control method being applied to a phase-shifted full-bridge converter including a controller 1, a phase-shifted full-bridge circuit 2, and a first capacitor Cd1 and a second capacitor Cd2, as shown in Fig. 3, and the control method including the following steps:

[0066] S10: When it is detected that the working state of the phase-shifted full-bridge circuit meets a preset condition, determining the target turn-on time of each switch tube of the phase-shifted full-bridge circuit according to the power demand value and the circuit element information;

[0067] S11: Determining the target duty cycle and the output period of the phase-shifted full-bridge circuit according to the target turn-on time and a preset corresponding relationship; wherein the preset corresponding relationship is the corresponding relationship between the duty cycle and the turn-on time and the circuit output power in the current discontinuous mode;

[0068] S12: Controlling the conduction timing of the switch tube of the phase-shifted full-bridge circuit according to the output period and the target duty cycle, so that the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer of the phase-shifted full-bridge circuit are in a resonant state in the turn-off time of the phase-shifted full-bridge circuit.

[0069] As shown in Fig. 2, the phase-shifted full-bridge converter provided by the present application includes a controller 1, a primary bridge arm circuit, a transformer, a first diode D1, a second diode D2, a first capacitor Cd1, a second capacitor Cd2, a third capacitor Cr1, and a fourth capacitor Cr2; the first end of the secondary winding of the transformer is connected to the second end of the first capacitor Cd1 and the first end of the second capacitor Cd2, the second end of the secondary winding of the transformer is connected to the anode of the first diode D1 and the cathode of the second diode D2, the cathode of the first diode D1 and the first end of the first capacitor Cd1 are commonly connected as the first output end of the phase-shifted full-bridge converter, the anode of the second diode D2 and the second end of the second capacitor Cd2 are commonly connected as the second output end of the phase-shifted full-bridge converter; the third capacitor Cr1 is connected in parallel with the first diode D1, and the fourth capacitor Cr2 is connected in parallel with the second diode D2; the controller 1 is configured to obtain a power output instruction to determine the working state of the phase-shifted full-bridge converter and the control strategy corresponding to the working state according to the power output instruction.

[0070] In the implementation process, the primary side bridge arm circuit comprises: a first bridge arm and a second bridge arm; the first ends of the first bridge arm and the second bridge arm are connected, and the second ends of the first bridge arm and the second bridge arm are commonly connected; the midpoint of the first bridge arm is connected with the first end of the transformer primary side circuit, and the midpoint of the second bridge arm is connected with the second end of the transformer primary side circuit; correspondingly, the controller 1 judging whether the phase-shifted full-bridge circuit satisfies the preset condition can be judging whether the power output instruction is greater than the power threshold value; if greater than the power threshold value, it is determined that the phase-shifted full-bridge converter is in a high-power output state, and does not satisfy the preset condition; if not greater than the power threshold value, it is determined that the phase-shifted full-bridge converter is in a low-power output device, and satisfies the preset condition. In addition, the controller 1 controlling whether the phase-shifted full-bridge circuit satisfies the preset condition can also judge whether the switching frequency of the switching tube is greater than the preset frequency, and if greater than the preset frequency, it is determined that the preset condition is satisfied.

[0071] Specifically, when greater than the power threshold value, the phase-shifted full-bridge circuit 2 is in a current continuous mode, and in this mode, there are six modes in a period of the current continuous mode, and the specific conditions are as follows:

[0072] As shown in FIG. 4, mode one (t0-t1) is specifically:

[0073] At time t0, the inverter completes commutation, and the first switching tube Q1 and the fourth switching tube Q4 are forwardly turned on. The transformer primary side circuit current, starting from zero, flows through the first switching tube Q1, the leakage inductance, the transformer, and the fourth switching tube Q4 in a forward direction and continuously increases. The transformer secondary side D1 enters a cut-off state, the Cd1 voltage increases from zero and is charged, and the Cd2 voltage decreases from Vm and is discharged. The resonance capacitor Cr1 voltage decreases from the maximum value and is discharged, and the resonance capacitor Cr2 voltage increases from the minimum value and is charged. At time t1, Cd1 is charged to Vm, Cd2 is discharged to zero, and D2 is turned on. In mode one, the topology does not output current to Vm, and Lr / Lm / Cd1 / Cd2 / Cr1 / Cr2 participate in resonance at the same time.

[0074] As shown in FIG. 5, mode two (t1-t2) is specifically:

[0075] From mode one to mode two, the control signal of the controller 1 does not change, and the capacitors Cd1 / Cd2 no longer participate in resonance under the voltage clamping action of the rectifier diode. In the t1-t2 time period, the first switching tube Q1 and the fourth switching tube Q4 are forwardly turned on. The transformer primary side circuit current, maintaining a forward direction, flows through the first switching tube Q1, the leakage inductance, the transformer, and the fourth switching tube Q4. The rectifier diode D1 maintains a cut-off state, the Cd1 voltage is Vm, the Cd2 voltage is zero, and D2 is turned on. The resonance capacitor Cr1 voltage continuously decreases and is discharged, and the resonance capacitor Cr2 voltage continuously increases and is charged. In mode two, the topology outputs current to Vm, and Lr / Lm / Cr1 / Cr2 participate in resonance at the same time.

[0076] As shown in Figure 6, the third mode (t2-t3) is as follows:

[0077] At time t2, the first switch Q1 is turned off, and the fourth switch Q4 remains on. In the third mode, the input DC source Vg does not input current to the topology, and the Lr freewheeling current provides current to the topology in this time period. The transformer primary side circuit current remains forward, and the current continuously decreases through Lr, the transformer, the fourth switch Q4, and the body diode of the second switch Q2. The rectifier diode D1 remains in the cut-off state, the voltage of Cd1 is Vm, the voltage of Cd2 is zero, and D2 is on. The voltage of the resonant capacitor Cr1 continuously decreases and is discharged, and the voltage of the resonant capacitor Cr2 continuously increases and is charged. At time t3, the transformer primary side current and the D2 current freewheel to zero, and D2 is cut off. At this time, Cr1 is discharged to the lowest voltage, and Cr2 is charged to the highest voltage.

[0078] In the third mode (t3-t4), the topology outputs current to Vm, and Lr / Lm / Cr1 / Cr2 participate in resonance at the same time. The fourth, fifth, and sixth modes are completely symmetrical to the first, second, and third modes, and will not be described again.

[0079] When the power threshold is not greater than the power threshold, the phase-shifted full-bridge converter is in the current discontinuous mode, and in this mode, there are eight modes in one period, and the specific conditions are as follows:

[0080] The first, second, and third modes in the current discontinuous mode are completely the same as those in the current continuous mode. The fourth mode is an additional mode in the current discontinuous mode compared with the current continuous mode, and the fourth mode is divided into two sections, the fourth one and the fourth two. During this period, the transformer current is reversed multiple times and provides conditions for entering the fifth mode to realize soft switching.

[0081] Figure 7 is a main waveform diagram of the modes in the current continuous mode of the present application. From top to bottom, it includes the output voltage of the full-bridge, the voltage and current of the transformer primary side excitation inductance Lm, the voltage and current of the transformer primary side leakage inductance, the voltage and current of the resonant capacitor Cr1, the voltage and current of the resonant capacitor Cr2, the voltage and current of the resonant capacitor Cd1, the voltage and current of the resonant capacitor Cd2, the voltage and current of the rectifier diode D1, the voltage and current of the rectifier diode D2, and the output current of the full-bridge. As shown in Figure 7, the voltage waveform output by the full-bridge circuit under control corresponds to the current and the transformer primary side leakage inductance current. The sum of the Cr1 / Cr2 voltages is always Vm, and the currents are always equal in size and opposite in direction. Cd1 and D1 are in parallel, and Cd2 and D2 are in parallel, so their voltage curves are completely the same. Cd1 and Cd2 only participate in resonance when the current is not zero in the first mode (t0-t1) and the fourth mode (t3-t4), and do not participate in resonance in the remaining modes. The output voltage is constant at Vm, and the current changes with the mode.

[0082] The mode four one (t3-t4) is shown in Fig. 8, the transformer primary side freewheeling current is reduced to 0 and reverses at t3, the second switch Q2 and the fourth switch Q4 are kept on, and the first switch Q1 and the third switch Q3 are kept off at the moment before and after. The input DC source Vg does not input current to the topology in the mode four one, and the Lr provides current to the topology. The transformer primary side circuit current is kept reversed, passing through Lr, transformer, body diode of the second switch Q2 and the fourth switch Q4. The rectifier diode D1 is kept off, the D2 is off, the Cd1 starts to discharge, and the Cd2 starts to charge. The resonant capacitor Cr1 is charged through the Cd1, and the voltage increases. The resonant capacitor Cr2 is discharged through the Cd2, and the voltage decreases. In the mode four one, the Vm only plays a voltage clamping role, and the topology does not transmit energy to it, and the Lr / Lm / Cr1 / Cr2 / Cd1 / Cd2 participates in resonance at the same time. At t4, the transformer primary side current is again freewheeling to 0 and reverses.

[0083] In the mode four two (t4-t5), as shown in Fig. 9, the transformer primary side freewheeling current is again freewheeling to 0 at t4, and the direction changes from negative to positive. The second switch Q2 and the fourth switch Q4 are kept on, and the first switch Q1 and the third switch Q3 are kept off at the moment before and after. The input DC source Vg does not input current to the topology in the mode four two, and the Lr provides current to the topology. The transformer primary side circuit current is kept positive, passing through Lr, transformer, body diode of the fourth switch Q4 and the second switch Q2. The rectifier diodes D1 and D2 are kept off, the Cd1 starts to charge, and the Cd2 starts to discharge. The resonant capacitor Cr1 is discharged through the Cd1, and the voltage decreases. The resonant capacitor Cr2 is charged through the Cd2, and the voltage increases. In the mode four two, the Vm only plays a voltage clamping role, and the topology does not transmit energy to it, and the Lr / Lm / Cr1 / Cr2 / Cd1 / Cd2 participates in resonance at the same time. At t5, the transformer primary side current is again freewheeling to 0 and reverses.

[0084] The mode four (including the mode four one and the mode four two) is a free resonance state, and the third switch Q3 and the fourth switch Q4 of the lagging bridge arm can provide soft switching conditions in the mode four two. In the current discontinuous mode, as long as the energy in the resonant cavity can still maintain the resonance state, the time length (free resonance period number) of the mode four can be arbitrarily adjusted according to the control needs.

[0085] The mode eight and the mode four are symmetrical, the third switch Q3 is off, and the fourth switch Q4 is on, and the soft switching principle is the same, which will not be described here.

[0086] Fig. 10 is a main waveform diagram of the mode of the current discontinuous mode of the application, and Fig. 11 is another waveform diagram of the mode of the current discontinuous mode of the application, from top to bottom including the output voltage of the full bridge, the voltage and current of the magnetizing inductance Lm of the primary side of the transformer, the voltage and current of the leakage inductance of the primary side of the transformer, the voltage and current of the resonance capacitor Cr1, the voltage and current of the resonance capacitor Cr2, the voltage and current of the resonance capacitor Cd1, the voltage and current of the resonance capacitor Cd2, the voltage and current of the rectifier diode D1, the voltage and current of the rectifier diode D2, and the output current of the full bridge.

[0087] The topology of the application is controlled as follows. The single-phase full-bridge primary side of the transformer circuit is composed of four MOSFETs, namely the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4. The first switch Q1 and the second switch Q2 form the leading bridge arm, and the third switch Q3 and the fourth switch Q4 form the lagging bridge arm. The single-phase full-bridge output is connected to the primary side of the transformer, where Lr is the leakage inductance of the primary side of the transformer, and Lm is the magnetizing inductance Lm of the primary side of the transformer. The secondary side of the transformer is connected to the rectifier diodes D1 / D2, and the resonance capacitors Cr1 / Cr2, both of which have a capacitance of Cr. The first diode D1 and the second diode D2 are respectively connected in parallel with the first capacitor Cd1 and the second capacitor Cd2, both of which have a capacitance of Cd.

[0088] The primary side uses the phase-shifted full-bridge technology to achieve soft switching (ZVS) control of the leading bridge arm using the transformer leakage inductance Lr freewheeling and the body diode and parasitic capacitor of the MOSFET, while achieving soft switching (ZCS) control of the lagging bridge arm using the transformer leakage inductance Lr freewheeling and natural turn-off of the rectifier diodes in the secondary side. During the process of charging and discharging of the capacitors Cd1 / Cd2 while the rectifier diodes in the secondary side are all turned off, the topology does not charge the secondary side Vm. During this period, the transformer leakage inductance Lr is charged by the input DC source of the primary side, storing energy until the capacitors Cd1 / Cd2 in the secondary side are fully charged and discharged, the rectifier diodes complete commutation and start to supply power to Vm. At this time, due to the inability of the primary side leakage inductance Lr current to change abruptly, an induced electromotive force is generated to maintain the original current, and the input voltage Vg is superimposed to supply power to the transformer, thereby achieving the ability to increase the input voltage range and improving the boost ratio of the topology.

[0089] In the continuous current mode, the transformer current cannot be abruptly changed, so the current in the bridge arm is transferred from the body diode of the first switch Q1 to the body diode of the second switch Q2 after the first switch Q1 is turned off, which provides a condition for the zero-voltage switching (ZVS) of the second switch Q2. In the conversion process from the mode five to the mode six, the second switch Q2 is turned off, and the first switch Q1 is turned on in the soft switching principle. In the mode three, the transformer current continues to flow to be close to 0, so the fourth switch Q4 can achieve the zero-current switching (ZCS), and because the transformer current cannot be abruptly changed, the current in the bridge arm is transferred from the fourth switch Q4 to the body diode of the third switch Q3, which provides a condition for the zero-voltage switching (ZVS) of the third switch Q3. At the end of the mode six, the third switch Q3 is turned off, and the fourth switch Q4 is turned on in the soft switching principle.

[0090] In the discontinuous current mode, the soft switching of the leading bridge arm is achieved in the same way as in the continuous current mode.

[0091] In the mode four in the discontinuous current mode, the transformer primary current forms a loop through the body diode of the second switch Q2 and the body diode of the fourth switch Q4, and when the transformer current continues to flow to be close to 0, the fourth switch Q4 can achieve the zero-current switching (ZCS), and because the transformer current cannot be abruptly changed, the current in the bridge arm is transferred from the fourth switch Q4 to the body diode of the third switch Q3, which provides a condition for the zero-voltage switching (ZVS) of the third switch Q3. In the mode eight, the third switch Q3 is turned off, and the fourth switch Q4 is turned on in the soft switching principle. The discontinuous current mode reduces the switching frequency at low power transmission by adding the free resonance processes of the mode four and the mode eight, and still maintains the soft switching of the full-bridge control. After reducing the switching frequency, a larger effective switch-on time ton is needed for the same transmission power, which helps to stabilize the control at low power transmission and reduces the switching loss.

[0092] Based on the above control, the input current Iin can be obtained through the resonant device primary leakage inductance Lr, excitation inductance Lm, third capacitor Cr1, fourth capacitor Cr2, first capacitor Cd1, second capacitor Cd2, transformer turn ratio n, input and output voltages Vg and Vm, switching period T, and effective switch-on time ton. Because Lr, Lm, Cd1, Cd2, Cr1, Cr2, and the transformer turn ratio n are constants, the following equation is obtained:

[0093] Iin=I1(Vg,Vm,Lr,Lm,Cd,Cr,T,ton)=I2(Vg,Vm,T,ton);

[0094] The input power Pin can be further obtained as Iin*Vg.

[0095] Based on the above transformer primary side lag bridge arm soft switching (ZCS) control mode can be derived effective opening time (mode one and mode two) :

[0096] ton = ton1 (Vm / Vg, Lr, Lm, Cd, Cr, T) = ton2 (Vm / Vg, T) ;

[0097] Phase shift time (mode three) :

[0098] tps = T / 2 - ton = tps (Vm / Vg, T).

[0099] The application provides a phase-shift full-bridge converter control method, comprising: when it is detected that the working state of the phase-shift full-bridge circuit meets a preset condition, determining the target turn-on time of each switch tube of the phase-shift full-bridge circuit according to the power demand value and the circuit element information, so as to increase the turn-on time of the switch tube while ensuring that the output power of the phase-shift full-bridge circuit is unchanged, thereby reducing the switching frequency of the switch tube; determining the target duty cycle and the output period of the phase-shift full-bridge circuit according to the target turn-on time and a preset corresponding relationship; wherein the preset corresponding relationship is the corresponding relationship between the duty cycle, the turn-on time and the circuit output power in the current discontinuous mode; and controlling the conduction timing of the switch tube of the phase-shift full-bridge circuit according to the output period and the target duty cycle, so that the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer of the phase-shift full-bridge circuit are in a resonant state within the turn-off time of the phase-shift full-bridge circuit. As can be seen, in the technical solution provided by the application, when the working state of the phase-shift full-bridge circuit meets the preset condition, the target turn-on time of the switch tube is determined according to the corresponding relationship between the turn-on time of the switch tube in the current continuous mode and the current discontinuous mode, and the target duty cycle is determined according to the corresponding relationship between the duty cycle, the turn-on time and the circuit output power in the current discontinuous mode, so that the phase-shift full-bridge circuit enters the current discontinuous mode, thereby reducing the switching loss of the switch tube. Further, by controlling the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer of the phase-shift full-bridge circuit to be in a resonant state within the turn-off time of the phase-shift full-bridge circuit, the soft switching of the circuit is realized, thereby further reducing the switching loss.

[0100] On the basis of the above embodiment, determining the turn-off time of the phase-shift full-bridge circuit 2 according to the circuit element information comprises: determining the performance information of the switch tube according to the circuit element information; determining a preset frequency that makes the output power of the phase-shift full-bridge circuit 2 meet the demand and the switching loss of the switch tube is minimum according to the corresponding relationship between the performance information, the power demand value and the switching loss of the switch tube and the circuit output power; determining the turn-on time of the switch tube corresponding to the preset frequency, and determining the turn-off time of the phase-shift full-bridge circuit 2 according to the turn-on time of the switch tube.

[0101] Correspondingly, the determining whether the power demand value meets the preset condition comprises: obtaining the power demand value; determining whether the power demand value is greater than a power threshold value; wherein the power threshold value is a value determined according to a limit switching frequency, and the limit switching frequency is a value determined according to a corresponding relationship between switching frequencies of the switching tubes in the phase-shifted full-bridge circuit 2 and switching losses. If the power demand value is not greater than the power threshold value, it is determined that the power demand value does not meet the preset condition.

[0102] In the above embodiments, the phase-shifted full-bridge converter control method is described in detail, and the present application also provides corresponding embodiments of the phase-shifted full-bridge converter control device. It should be noted that the embodiments of the device part are described from two angles, one is based on the functional module angle, and the other is based on the hardware angle.

[0103] FIG. 12 is a structural diagram of a phase-shifted full-bridge converter control device provided by an embodiment of the present application, as shown in FIG. 12, the control device comprises: a first determining module 10, configured to determine target turn-on times of the switching tubes of the phase-shifted full-bridge circuit according to a power demand value and circuit element information when it is detected that the working state of the phase-shifted full-bridge circuit meets a preset condition;

[0104] A second determining module 11, configured to determine a target duty cycle and an output period of the phase-shifted full-bridge circuit according to the target turn-on times and a preset corresponding relationship; wherein the preset corresponding relationship is a corresponding relationship between the duty cycle and the turn-on times, circuit output power in the current discontinuous mode;

[0105] A control module 12, configured to control the conduction timing of the switching tubes of the phase-shifted full-bridge circuit according to the output period and the target duty cycle, so that the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer of the phase-shifted full-bridge circuit are in a resonant state in the off time of the phase-shifted full-bridge circuit.

[0106] Since the embodiments of the device part correspond to the embodiments of the method part, the embodiments of the device part are described in the description of the embodiments of the method part, which will not be described here.

[0107] The application provides a phase-shift full-bridge converter control device, comprising: the application provides a phase-shift full-bridge converter control method, comprising: when it is detected that the working state of the phase-shift full-bridge circuit meets a preset condition, determining the target turn-on time of each switch tube of the phase-shift full-bridge circuit according to the power demand value and the circuit element information, so as to increase the turn-on time of the switch tube while ensuring that the output power of the phase-shift full-bridge circuit is unchanged, thereby reducing the switching frequency of the switch tube; determining the target duty cycle and the output period of the phase-shift full-bridge circuit according to the target turn-on time and a preset corresponding relationship; wherein the preset corresponding relationship is the corresponding relationship between the duty cycle, the turn-on time and the circuit output power in the current discontinuous mode; and controlling the conduction timing of the switch tube of the phase-shift full-bridge circuit according to the output period and the target duty cycle, so that the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer of the phase-shift full-bridge circuit are in a resonant state within the turn-off time of the phase-shift full-bridge circuit. Therefore, in the technical solution provided by the application, when the working state of the phase-shift full-bridge circuit meets the preset condition, the target turn-on time of the switch tube is determined according to the corresponding relationship between the turn-on time of the switch tube in the current continuous mode and the current discontinuous mode, and the target duty cycle is determined according to the corresponding relationship between the duty cycle, the turn-on time and the circuit output power in the current discontinuous mode, so that the phase-shift full-bridge circuit enters the current discontinuous mode, thereby reducing the switching loss of the switch tube. Further, by controlling the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer of the phase-shift full-bridge circuit to be in a resonant state within the turn-off time of the phase-shift full-bridge circuit, the soft switching of the circuit is realized, thereby further reducing the switching loss.

[0108] Fig. 13 is a structural diagram of another phase-shift full-bridge converter control device provided by the application, as shown in Fig. 13, the phase-shift full-bridge converter control device comprises: a memory 20 for storing a computer program;

[0109] A processor 21 is configured to execute the computer program to realize the steps of the phase-shift full-bridge converter control device method of the above-mentioned embodiments.

[0110] The phase-shift full-bridge converter control device provided by the embodiment can include but is not limited to a smart phone, a tablet computer, a notebook computer or a desktop computer, etc.

[0111] The processor 21 can include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 21 can be implemented in at least one of a hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), a programmable logic array (PLA), etc. The processor 21 can also include a main processor and a coprocessor. The main processor is a processor for processing data in a wake-up state, also referred to as a central processing unit (CPU). The coprocessor is a low-power processor for processing data in a standby state. In some embodiments, the processor 21 can be integrated with a graphics processor (GPU) for rendering and drawing content required to be displayed by the display screen. In some embodiments, the processor 21 can further include an artificial intelligence (AI) processor for processing computing operations related to machine learning.

[0112] The memory 20 can include one or more computer-readable storage media, which can be non-transitory. The memory 20 can further include a high-speed random access memory, and a nonvolatile memory such as one or more disk storage devices, flash storage devices. In this embodiment, the memory 20 is at least used to store the following computer program 201, wherein the computer program is loaded and executed by the processor 21, and can implement the related steps of the phase-shifted full-bridge converter control method disclosed in any of the preceding embodiments. In addition, the resources stored by the memory 20 can further include an operating system 202 and data 203, etc., and the storage mode can be temporary storage or permanent storage. The operating system 202 can include Windows, Unix, Linux, etc.

[0113] In some embodiments, the phase-shifted full-bridge converter control apparatus can further include a display screen 22, an input / output interface 23, a communication interface 24, a power supply 25, and a communication bus 26.

[0114] Those skilled in the art can understand that the structure shown in FIG. 13 does not constitute a limitation on the phase-shifted full-bridge converter control apparatus, and can include more or fewer components than those shown.

[0115] The phase-shifted full-bridge converter control device provided by the embodiments of the present application comprises a memory and a processor. When the processor executes the program stored in the memory, the following method can be implemented: when it is detected that the working state of the phase-shifted full-bridge circuit meets the preset condition, the target turn-on time of each switch tube of the phase-shifted full-bridge circuit is determined according to the power requirement value and the circuit element information; the target duty cycle and the output period of the phase-shifted full-bridge circuit are determined according to the target turn-on time and the preset corresponding relationship; wherein the preset corresponding relationship is the corresponding relationship of the duty cycle, the turn-on time and the circuit output power in the current discontinuous mode; the conduction timing of the switch tube of the phase-shifted full-bridge circuit is controlled according to the output period and the target duty cycle, so that the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer of the phase-shifted full-bridge circuit are in the resonant state within the turn-off time of the phase-shifted full-bridge circuit.

[0116] Finally, the present application also provides an embodiment corresponding to a computer readable storage medium. The computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the steps described in the above method embodiment.

[0117] It can be understood that if the method in the above embodiments is implemented in the form of a software function unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and executes all or part of the steps of the embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk and various media that can store program codes.

[0118] The phase-shifted full-bridge converter and the control method, device and medium thereof provided by the present application are described in detail above. The embodiments in the specification are described in a progressive manner, and each embodiment mainly describes the differences from other embodiments. The same or similar parts of each embodiment can be referred to. For the device disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the related parts can be referred to the method part. It should be pointed out that, for ordinary skilled in the art, without departing from the principles of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

[0119] It also needs to be explained that in the present specification, the relational terms such as first and second and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations 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 more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

Claims

1. A phase-shifted full-bridge converter, characterized in that: include: A controller, a phase-shifted full-bridge circuit, a first capacitor, and a second capacitor; The phase-shifted full-bridge circuit includes a first bridge arm circuit, a second bridge arm circuit, an excitation inductor, a transformer and a first diode, a second diode, a third capacitor, and a fourth capacitor; wherein the first end of the excitation inductor is connected to the midpoint of the first bridge arm circuit, the second end of the excitation inductor is connected to the first end of the primary side of the transformer, and the second end of the primary side of the transformer is connected to the midpoint of the second bridge arm circuit; the first end of the secondary side of the transformer is connected to the second end of the third capacitor and the first end of the fourth capacitor, the second end of the secondary side of the transformer is connected to the anode of the first diode and the cathode of the second diode, the cathode of the first diode and the first end of the third capacitor are connected together as a first output end, and the anode of the second diode and the second end of the fourth capacitor are connected together as a second output end; The first capacitor is connected in parallel with the first diode on the secondary side of the phase-shift full-bridge circuit, and the second capacitor is connected in parallel with the second diode on the secondary side of the phase-shift full-bridge circuit; The controller is connected to the control end of each switch tube of the phase-shifted full-bridge circuit.

2. A phase-shifted full-bridge converter control method, characterized in that: Applied to the phase-shifted full-bridge converter according to claim 1, the control method comprises: When it is detected that the working state of the phase-shifted full-bridge circuit meets the preset conditions, the target turn-on time of each switch tube of the phase-shifted full-bridge circuit is determined according to the power demand value and the circuit component information; Determining a target duty cycle and an output period of the phase-shifted full-bridge circuit according to the target on-time and a preset corresponding relationship; wherein the preset corresponding relationship is a corresponding relationship between the duty cycle, the on-time, and the circuit output power in the current discontinuous mode; The conduction timing of the switch tube of the phase-shift full-bridge circuit is controlled according to the output period and the target duty cycle, so that the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer of the phase-shift full-bridge circuit are in a resonant state during the off time of the phase-shift full-bridge circuit.

3. The phase-shifted full-bridge converter control method according to claim 2, characterized in that: Determining whether the operating state of the phase-shifted full-bridge circuit meets the preset condition includes: Acquire the real-time switching frequency of the switch tube of the phase-shift full-bridge circuit and the power demand value of the phase-shift full-bridge circuit; When the real-time switching frequency is greater than the limit switching frequency and / or the power demand value is lower than the preset power, it is determined that the working state of the phase-shifted full-bridge circuit does not meet the preset conditions; wherein, the limit switching frequency is a value determined according to the corresponding relationship between the switching frequency and switching loss of each switching tube in the phase-shifted full-bridge circuit.

4. The phase-shifted full-bridge converter control method according to claim 3, characterized in that: Determining the target turn-on time of each switch tube of the phase-shifted full-bridge circuit according to the power demand value and circuit element information includes: Determining performance information of the switch tube according to the circuit element information; According to the corresponding relationship between the performance information, the power demand value, the switching loss of the switch tube, and the circuit output power, the preset frequency and the target turn-on time are determined so that the output power of the phase-shifted full-bridge circuit meets the demand and the switching loss of the switch tube is minimized.

5. The phase-shifted full-bridge converter control method according to claim 3, wherein: Determining the target duty cycle and the output period of the phase-shifted full-bridge circuit according to the target on-time and the preset corresponding relationship includes: Obtaining the corresponding relationship between the switch-on time, the duty cycle, and the circuit output power in the current discontinuous mode; The target duty cycle and the output period of the phase-shifted full-bridge circuit are determined according to the target turn-on time and the corresponding relationship.

6. The phase-shifted full-bridge converter control method according to claim 2, wherein: During the off time, controlling the first capacitor, the second capacitor, the third capacitor, the fourth capacitor, and the transformer to be in the resonant state includes: During a first resonant cycle, the second switch tube and the fourth switch tube of the phase-shifted full-bridge circuit are controlled to be turned on, and the first switch tube and the third switch tube are turned off, so as to control the first capacitor, the second capacitor, the transformer, the third capacitor, and the fourth capacitor to enter a resonant state; During a second resonant period, the second switch tube and the fourth switch tube of the phase-shifted full-bridge circuit are controlled to be turned off, and the first switch tube and the third switch tube are turned on, so as to control the first capacitor, the second capacitor, the transformer, the third capacitor, and the fourth capacitor to enter a resonant state; After the step of controlling the first capacitor, the second capacitor, the third capacitor, the fourth capacitor, and the transformer to enter a resonant state, the method further includes: The number of cycles of the resonant state is determined according to the turn-off time to determine the time of the resonant state.

7. The phase-shifted full-bridge converter control method according to claim 6, characterized in that: Also includes: When the power demand value meets the preset condition, the phase-shifted full-bridge circuit is controlled to be in a current continuous mode.

8. A phase-shifted full-bridge converter control device, characterized in that: Applied to the phase-shifted full-bridge converter according to claim 1, the control device comprises: A first determining module is configured to determine a target turn-on time of each switch tube of the phase-shifted full-bridge circuit according to a power demand value and circuit component information when detecting that the working state of the phase-shifted full-bridge circuit meets a preset condition; a second determining module, configured to determine a target duty cycle and an output period of the phase-shifted full-bridge circuit according to the target on-time and a preset corresponding relationship; wherein the preset corresponding relationship is a corresponding relationship between the duty cycle, the on-time, and the circuit output power in the current discontinuous mode; A control module is used to control the conduction timing of the switch tube of the phase-shift full-bridge circuit according to the output period and the target duty cycle, so that the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the transformer of the phase-shift full-bridge circuit are in a resonant state during the off time of the phase-shift full-bridge circuit.

9. A phase-shifted full-bridge converter control device, characterized in that: including a memory for storing a computer program; A processor, configured to implement the steps of the phase-shifted full-bridge converter control method according to any one of claims 2 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the phase-shifted full-bridge converter control method according to any one of claims 2 to 7 are implemented.

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