Control Method, Device, Converter and Control System of Phase-Shifted Full-Bridge Converter

Abstract

The present disclosure relates to a control method, device, converter and control system for a phase-shifted full-bridge converter, and relates to the field of power electronics technology. The method includes: obtaining control parameters of low-voltage control signals corresponding to a plurality of second control switches, determining a target phase-shift angle of a low-voltage module according to a switching control period and a switching conduction period, adjusting a phase angle of the low-voltage control signal according to the target phase-shift angle, controlling the plurality of second control switches according to the adjusted low-voltage control signal, and controlling the plurality of first control switches according to a specified duty cycle, so that the phase-shifted full-bridge converter outputs a target voltage. The phase angle of the low-voltage side can be dynamically adjusted according to the target phase-shift angle determined by the control parameters of the low-voltage control signal, which can reduce the current stress on the low-voltage side while ensuring the load-carrying capacity of the phase-shifted full-bridge converter, reduce the heat generation of the second control switches on the low-voltage side, and improve the practicability, expandability and safety of the phase-shifted full-bridge converter.

Description

Technical Field

[0001] The present disclosure relates to the field of power electronics technology, and in particular, to a control method, device, converter, and control system for a phase-shifted full-bridge converter. Background Art

[0002] With the continuous development of distributed energy systems such as new energy power generation and electric vehicles, due to its good electrical isolation and high power density, the phase-shifted full-bridge converter has been widely used as a practical topology in various high-power applications. Currently, mainly by controlling the control switches on the low-voltage side of the phase-shifted full-bridge converter and the control switches on the high-voltage side of the phase-shifted full-bridge converter respectively according to a duty cycle of 50%, the phase-shifted full-bridge converter outputs the corresponding voltage. However, adopting this control method will result in relatively large current stress on the low-voltage side of the phase-shifted full-bridge converter, and relatively large heat generation of the control switches on the low-voltage side, causing the phase-shifted full-bridge converter to only meet the application scenarios of small voltage input, small voltage and small current output, which affects the practicability and expandability of the phase-shifted full-bridge converter. Summary of the Invention

[0003] To solve the problems existing in the related art, the present disclosure provides a control method, device, converter, and control system for a phase-shifted full-bridge converter.

[0004] To achieve the above object, according to the first aspect of the embodiments of the present disclosure, there is provided a control method for a phase-shifted full-bridge converter. The phase-shifted full-bridge converter includes a high-voltage module, a low-voltage module, and a transformer. The high-voltage module is connected to the low-voltage module through the transformer. The high-voltage module includes a first bridge arm and a second bridge arm, and the low-voltage module includes a third bridge arm and a fourth bridge arm. A plurality of first control switches are respectively arranged on the first bridge arm and the second bridge arm, and a plurality of second control switches are respectively arranged on the third bridge arm and the fourth bridge arm. The method includes:

[0005] Obtaining control parameters of a low-voltage control signal corresponding to the plurality of second control switches; the control parameters include a switch control period and a switch conduction period;

[0006] Determining a target phase-shift angle of the low-voltage module according to the switch control period and the switch conduction period;

[0007] Adjusting the phase angle of the low-voltage control signal according to the target phase-shift angle, controlling the plurality of second control switches according to the adjusted low-voltage control signal, and controlling the plurality of first control switches according to a specified duty cycle, so that the phase-shifted full-bridge converter outputs a target voltage.

[0008] Optionally, determining the target phase-shift angle of the low-voltage module according to the switch control period and the switch conduction period includes:

[0009] Determining the target phase-shift angle based on a preset relationship according to the switch control period and the switch conduction period; the preset relationship is to determine a target period parameter according to the switch control period and the switch conduction period, and determine the target phase-shift angle according to the target period parameter and the switch control period; the target period parameter is used to indicate the difference between the switch conduction period and the switch off period.

[0010] Optionally, adjusting the phase angle of the low-voltage control signal according to the target phase-shift angle, and controlling the plurality of second control switches according to the adjusted low-voltage control signal includes:

[0011] Phase-shifting the low-voltage control signal according to the target phase-shift angle to adjust the phase-shift angle of the low-voltage control signal and generate the adjusted low-voltage control signal;

[0012] Controlling the plurality of second control switches according to the adjusted low-voltage control signal so that the third bridge arm and the fourth bridge arm lead the first bridge arm or the second bridge arm by the target phase-shift angle.

[0013] Optionally, controlling the plurality of second control switches according to the adjusted low-voltage control signal includes:

[0014] Adjusting the adjusted low-voltage control signal according to a preset duty cycle to obtain a target low-voltage control signal;

[0015] Controlling the plurality of second control switches according to the target low-voltage control signal so that the third bridge arm and the fourth bridge arm lead the first bridge arm or the second bridge arm by the target phase-shift angle and the plurality of second control switches conduct according to the preset duty cycle.

[0016] Optionally, the specified duty cycle is 50%, and the preset duty cycle is greater than or equal to the specified duty cycle.

[0017] Optionally, the first bridge arm includes a first control switch and a second control switch connected to the first control switch, and the second bridge arm includes a third control switch and a fourth control switch connected to the third control switch; the third bridge arm includes a fifth control switch and a sixth control switch connected to the fifth control switch, and the fourth bridge arm includes a seventh control switch and an eighth control switch connected to the seventh control switch.

[0018] Optionally, the phase-shifted full-bridge converter further includes a first capacitor, a second capacitor, a third capacitor, a first inductor, and a second inductor;

[0019] The first end of the first control switch is respectively connected to the first end of the third control switch and the first end of the first capacitor; the second end of the second control switch is respectively connected to the second end of the fourth control switch and the second end of the first capacitor; the second end of the first control switch is respectively connected to the first end of the second control switch and the first end of the second capacitor, and the second end of the second capacitor is connected to the first end of the first inductor; the second end of the first inductor is connected to the first end of the low-voltage side of the transformer, and the second end of the third control switch is respectively connected to the first end of the fourth control switch and the second end of the low-voltage side of the transformer;

[0020] The first end of the fifth control switch is respectively connected to the first end of the seventh control switch, the first end of the third capacitor, and the first end of the second inductor; the second end of the sixth control switch is respectively connected to the second end of the eighth control switch and the second end of the third capacitor; the second end of the fifth control switch is respectively connected to the first end of the sixth control switch and the first end of the high-voltage side of the transformer, and the second end of the seventh control switch is respectively connected to the first end of the eighth control switch and the second end of the high-voltage side of the transformer.

[0021] According to a second aspect of the embodiments of the present disclosure, there is provided a control device for a phase-shifted full-bridge converter, the device including:

[0022] A memory having a computer program stored thereon;

[0023] A processor for executing the computer program in the memory to implement the steps of the method according to any one of the first aspect.

[0024] According to a third aspect of the embodiments of the present disclosure, there is provided a phase-shifted full-bridge converter, the phase-shifted full-bridge converter including a high-voltage module, a low-voltage module, a transformer, and the control device according to the second aspect; the high-voltage module is connected to the low-voltage module through the transformer; the control device is respectively connected to the high-voltage module and the low-voltage module.

[0025] According to a fourth aspect of the embodiments of the present disclosure, there is provided a control system for a phase-shifted full-bridge converter, the control system including a phase-shifted full-bridge converter and the control device according to the second aspect; the phase-shifted full-bridge converter is connected to the control device.

[0026] Through the above technical solution, the present disclosure first obtains the control parameters of the low-voltage control signals corresponding to multiple second control switches, where the control parameters include the switch control period and the switch conduction period, and determines the target phase-shift angle of the low-voltage module according to the switch control period and the switch conduction period. Then, the phase angle of the low-voltage control signal is adjusted according to the target phase-shift angle, and the multiple second control switches are controlled according to the adjusted low-voltage control signal, and the multiple first control switches are controlled according to a specified duty ratio, so that the phase-shifted full-bridge converter outputs a target voltage. The present disclosure can determine the target phase-shift angle according to the control parameters of the low-voltage control signals on the low-voltage side, and dynamically adjust the phase angle of the low-voltage side according to the target phase-shift angle, which can reduce the current stress on the low-voltage side while ensuring the load-carrying capacity of the phase-shifted full-bridge converter, reduce the heat generation of the second control switches on the low-voltage side, so that the phase-shifted full-bridge converter can be applied to more application scenarios, and improve the practicability, expandability and safety of the phase-shifted full-bridge converter.

[0027] Other features and advantages of the present disclosure will be described in detail in the following specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings are used to provide a further understanding of the present disclosure, and constitute a part of the specification. Together with the following specific implementation, they are used to explain the present disclosure, but do not constitute a limitation to the present disclosure. In the drawings:

[0029] Figure 1 is a flowchart of a control method for a phase-shifted converter shown according to an exemplary embodiment;

[0030] Figure 2 is a schematic diagram of a phase-shifted full-bridge converter connected in series in a loop application shown according to an exemplary embodiment;

[0031] Figure 3 is according to Figure 1 shown in the embodiment is a flowchart of step 103;

[0032] Figure 4 is a schematic diagram of a phase-shifted converter shown according to an exemplary embodiment;

[0033] Figure 5 is a block diagram of a control device for a phase-shifted converter shown according to an exemplary embodiment;

[0034] Figure 6 is a block diagram of a phase-shifted converter shown according to an exemplary embodiment;

[0035] Figure 7 is a block diagram of a control system for a phase-shifted full-bridge converter shown according to an exemplary embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The following will describe in detail the specific embodiments of the present disclosure with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustrating and explaining the present disclosure, and are not used to limit the present disclosure.

[0037] Figure 1 is a flowchart of a control method for a phase-shifted converter shown according to an exemplary embodiment. As Figure 1 shown, the phase-shifted full-bridge converter includes a high-voltage module, a low-voltage module, and a transformer. The high-voltage module is connected to the low-voltage module through the transformer. The high-voltage module includes a first bridge arm and a second bridge arm, and the low-voltage module includes a third bridge arm and a fourth bridge arm. A plurality of first control switches are respectively arranged on the first bridge arm and the second bridge arm, and a plurality of second control switches are respectively arranged on the third bridge arm and the fourth bridge arm. The method may include the following steps:

[0038] Step 101, obtain the control parameters of the low-voltage control signals corresponding to a plurality of second control switches. Among them, the control parameters include the switch control period and the switch conduction period.

[0039] Exemplarily, the current stress on the low-voltage side of the phase-shifted full-bridge converter can be reduced and the heat generation of the control switches on the low-voltage side can be reduced by changing the phase angle on the low-voltage side of the phase-shifted full-bridge converter. Specifically, the phase-shifted full-bridge converter may be composed of a high-voltage module, a low-voltage module, and a transformer. Among them, the high-voltage module is a module composed of the devices on the high-voltage side of the phase-shifted full-bridge converter, which may include a first bridge arm and a second bridge arm (i.e., the two bridge arms on the high-voltage side of the phase-shifted full-bridge converter), and a plurality of first control switches are respectively arranged on the first bridge arm and the second bridge arm. The low-voltage module is a module composed of the devices on the low-voltage side of the phase-shifted full-bridge converter, which may include a third bridge arm and a fourth bridge arm (i.e., the two bridge arms on the low-voltage side of the phase-shifted full-bridge converter), and a plurality of second control switches are respectively arranged on the third bridge arm and the fourth bridge arm. Further, the first control switches and the second control switches may be, for example, switch elements such as MOSFET (English: Metal-Oxide-Semiconductor Field-Effect Transistor, Chinese: Metal-Oxide-Semiconductor Field-Effect Transistor), IGBT (English: Insulated Gate Bipolar Transistor, Chinese: Insulated Gate Bipolar Transistor).

[0040] When the phase-shifted full-bridge converter is applied in series in a loop (a schematic diagram of the phase-shifted full-bridge converter applied in series in a loop can be as Figure 2As shown in the figure, first, the control parameters of the low-voltage control signals corresponding to multiple second control switches can be obtained. Among them, there are multiple low-voltage control signals, and each low-voltage control signal corresponds to a second control switch and is used to control its corresponding second control switch to conduct and turn off periodically. The control parameters of each low-voltage control signal include the switch control period and the switch conduction period. The switch conduction period is the high-level time of the control signal (i.e., the conduction time of the control switch), and the control switch is in the conduction state during the high-level time. The switch turn-off period is the low-level time of the control signal (i.e., the turn-off time of the control switch), and the control switch is in the turn-off state during the low-level time. The sum of the conduction time for the control switch to conduct once and the turn-off time for the control switch to turn off once is a switch control period (i.e., the sum of a switch conduction period and a switch turn-off period is a switch control period). The switch control period and the switch conduction period of each second control switch are the same. The schematic diagram of the phase-shifted full-bridge converter connected in series in the loop application can be as Figure 2 shown, Figure 2 In Figure 2 , HDC+ is the positive input terminal of the high-voltage module, HDC- is the negative input terminal of the high-voltage module, LDC+ is the positive output terminal of the low-voltage module, and LDC- is the negative output terminal of the low-voltage module.

[0041] Step 102: Determine the target phase-shift angle of the low-voltage module according to the switch control period and the switch conduction period.

[0042] In this step, a target phase-shift angle at which the two arms of the low-voltage module lead the arms of the high-voltage side of the phase-shifted full-bridge converter can be calculated according to the switch control period and the switch conduction period, which can reduce the current stress on the low-voltage side and reduce the heat generation of the second control switch.

[0043] Step 103: Adjust the phase angle of the low-voltage control signal according to the target phase-shift angle, control the multiple second control switches according to the adjusted low-voltage control signal, and control the multiple first control switches according to the specified duty cycle, so that the phase-shifted full-bridge converter outputs the target voltage.

[0044] For example, after obtaining the target phase-shifting angle, the low-voltage control signal can be phase-shifted according to the target phase-shifting angle to adjust the phase angle of the low-voltage control signal, and according to the adjusted low-voltage control signal, a plurality of second control switches are controlled so that the third bridge arm and the fourth bridge arm are ahead of the first bridge arm or the second bridge arm by the target phase-shifting angle. At the same time, a plurality of first control switches can also be controlled according to the specified duty ratio so that the phase-shifted full-bridge converter outputs the target voltage. Wherein, the specified duty ratio is 50%. By controlling the phase-shifted full-bridge converter to perform constant-voltage output in this way, it is not necessary to use voltage and current double closed-loop control. Only the target phase-shifting angle needs to be calculated according to the switching control period and the switching conduction period on the low-voltage side of the phase-shifted full-bridge converter. The control method is simple and easy to implement. Moreover, while ensuring the load-carrying capacity of the phase-shifted full-bridge converter, the current stress on the low-voltage side of the phase-shifted full-bridge converter can be reduced. At the same time, since the current stress on the low-voltage side of the phase-shifted full-bridge converter is reduced, the turn-on loss of the second control switch will also be reduced accordingly, thereby reducing the heat generation of the second control switch.

[0045] It should be noted that the control processes of steps 101-step 103 can be completed by a controller, and the controller can be, for example, an MCU (English: Microcontroller Unit, Chinese: Micro Control Unit), a PLC (English: Programmable Logic Controller, Chinese: Programmable Logic Controller) or a CPU (English: Central Processing Unit, Chinese: Central Processor), etc., which are processors with control functions.

[0046] In summary, the present disclosure first obtains the control parameters of the low-voltage control signals corresponding to a plurality of second control switches, where the control parameters include the switching control period and the switching conduction period, and determines the target phase-shifting angle of the low-voltage module according to the switching control period and the switching conduction period. Then, the phase angle of the low-voltage control signal is adjusted according to the target phase-shifting angle, and a plurality of second control switches are controlled according to the adjusted low-voltage control signal, and a plurality of first control switches are controlled according to the specified duty ratio so that the phase-shifted full-bridge converter outputs the target voltage. The present disclosure can determine the target phase-shifting angle according to the control parameters of the low-voltage control signals on the low-voltage side, and dynamically adjust the phase angle of the low-voltage side according to the target phase-shifting angle. In this way, while ensuring the load-carrying capacity of the phase-shifted full-bridge converter, the current stress on the low-voltage side can be reduced, and the heat generation of the second control switch on the low-voltage side can be reduced, so that the phase-shifted full-bridge converter can be applied to more application scenarios, improving the practicability, expandability and safety of the phase-shifted full-bridge converter.

[0047] Optionally, step 102 can be implemented in the following manner:

[0048] Determine the target phase-shift angle based on the switch control period and the switch conduction period according to a preset relationship. Wherein, the preset relationship is to determine the target period parameter according to the switch control period and the switch conduction period, and determine the target phase-shift angle according to the target period parameter and the switch control period. The target period parameter is used to indicate the difference between the switch conduction period and the switch turn-off period.

[0049] For example, a preset relationship for characterizing the switch control period, the switch conduction period, and the target phase-shift angle can be set in advance. After obtaining the switch control period and the switch conduction period, the target phase-shift angle of the low-voltage module when the current stress on the low-voltage side is minimized can be determined according to the switch control period and the switch conduction period by using this preset relationship. Wherein, the preset relationship can be a preset calculation formula or a relationship table.

[0050] When the preset relationship is a preset calculation formula, the preset calculation formula can be expressed as: θ = (T1 - (T - T1)) * 180 / T, where T is the switch control period, T1 is the switch conduction period, and T1 - (T - T1) is the target period parameter (i.e., the difference between the switch conduction period and the switch turn-off period). For example, when the switch control period is 20 us and the switch conduction period is 11 us, the target phase-shift angle can be calculated according to the preset calculation formula as: θ = (T1 - (T - T1)) * 180 / T = (11 - (20 - 11)) * 180 / 20 = 18°.

[0051] Figure 3 It is based on Figure 1 The flowchart of step 103 shown in the illustrated embodiment. As Figure 3 shown, step 103 may include the following steps:

[0052] Step 1031, phase-shift the low-voltage control signal according to the target phase-shift angle to adjust the phase-shift angle of the low-voltage control signal, and generate the adjusted low-voltage control signal.

[0053] Step 1032, control a plurality of second control switches according to the adjusted low-voltage control signal, so that the third bridge arm and the fourth bridge arm lead the first bridge arm or the second bridge arm by the target phase-shift angle.

[0054] Exemplarily, after obtaining the target phase-shift angle, within the preset phase-shift angle range, the low-voltage control signal corresponding to each second control switch can be phase-shifted according to the target phase-shift angle to adjust the phase-shift angle of each low-voltage control signal, and generate the adjusted low-voltage control signal corresponding to each second control switch. Considering the output capacitance of the phase-shifted full-bridge converter, the preset phase-shift angle range can be 55 - 75.

[0055] In order to reduce the current stress on the low-voltage side and decrease the heat generation of the second control switch, it is necessary to make the two arms of the low-voltage module lead the target phase-shift angle of the leading arm of the high-voltage side of the phase-shifted full-bridge converter. Therefore, when the first arm is the leading arm of the high-voltage side of the full-bridge converter, the second control switch is controlled according to the adjusted low-voltage control signal corresponding to each second control switch, so that the third arm and the fourth arm lead the target phase-shift angle relative to the first arm. When the second arm is the leading arm of the high-voltage side of the full-bridge converter, the second control switch is controlled according to the adjusted low-voltage control signal corresponding to each second control switch, so that the third arm and the fourth arm lead the target phase-shift angle relative to the second arm. Additionally, the circuit topology of the phase-shifted full-bridge converter can also be adjusted to reduce the current stress on the low-voltage side and decrease the heat generation of the second control switch when the two arms of the low-voltage module lead the lagging arm of the high-voltage side of the phase-shifted full-bridge converter by the target phase-shift angle.

[0056] Furthermore, to further reduce the current stress on the low-voltage side of the phase-shifted full-bridge converter, the duty cycle of the second control switch can be made greater than the specified duty cycle. Then, according to the preset duty cycle, the adjusted low-voltage control signal is adjusted to obtain the target low-voltage control signal. Based on the target low-voltage control signal, multiple second control switches are controlled so that the third arm and the fourth arm lead the target phase-shift angle relative to the first arm or the second arm, and the multiple second control switches are turned on according to the preset duty cycle.

[0057] It should be noted that the specified duty cycle is 50% (i.e., the duty cycle of the high-voltage side of the phase-shifted full-bridge converter is 50%), and the preset duty cycle is greater than or equal to the specified duty cycle (i.e., the preset duty cycle is greater than or equal to 50%). If the duty cycle of the high-voltage side of the phase-shifted full-bridge converter is greater than 50%, the first arm and the second arm will be short-circuited. If the duty cycle of the high-voltage side of the phase-shifted full-bridge converter is less than 50%, the energy transmitted by the transformer will be insufficient. By making the duty cycle of the second control switch greater than 50%, at a certain moment, the low-voltage side of the phase-shifted full-bridge converter will present a short-circuit state, preventing the energy of the transformer from being transmitted to the low-voltage side of the transformer, thus suppressing the increase in the peak-to-peak value of the current on the low-voltage side of the phase-shifted full-bridge converter and further reducing the current stress on the low-voltage side of the phase-shifted full-bridge converter.

[0058] In one scenario, such as Figure 4As shown, the first bridge arm may include a first control switch 61 and a second control switch 62 connected to the first control switch 61. The second bridge arm may include a third control switch 63 and a fourth control switch 64 connected to the third control switch 63. The third bridge arm may include a fifth control switch 71 and a sixth control switch 72 connected to the fifth control switch 71. The fourth bridge arm may include a seventh control switch 73 and an eighth control switch 74 connected to the seventh control switch 73. The phase-shifted full-bridge converter may further include a first capacitor 1, a second capacitor 2, a third capacitor 3, a first inductor 4, and a second inductor 5.

[0059] The first end of the first control switch 61 is respectively connected to the first end of the third control switch 63 and the first end of the first capacitor 3. The second end of the second control switch 62 is respectively connected to the second end of the fourth control switch 64 and the second end of the first capacitor 1. The second end of the first control switch 61 is respectively connected to the first end of the second control switch 62 and the first end of the second capacitor 2. The second end of the second capacitor 2 is connected to the first end of the first inductor 4. The second end of the first inductor 4 is connected to the first end of the low-voltage side of the transformer. The second end of the third control switch 63 is respectively connected to the first end of the fourth control switch 64 and the second end of the low-voltage side of the transformer.

[0060] The first end of the fifth control switch 71 is respectively connected to the first end of the seventh control switch 73, the first end of the third capacitor 3, and the first end of the second inductor 5. The second end of the sixth control switch 72 is respectively connected to the second end of the eighth control switch 74 and the second end of the third capacitor 3. The second end of the fifth control switch 71 is respectively connected to the first end of the sixth control switch 72 and the first end of the high-voltage side of the transformer. The second end of the seventh control switch 73 is respectively connected to the first end of the eighth control switch 74 and the second end of the high-voltage side of the transformer.

[0061] Exemplarily, when the phase-shifted full-bridge converter is applied in series in a loop and the first bridge arm is the leading bridge arm, first, the low-voltage control signals corresponding to the fifth control switch 71, the sixth control switch 72, the seventh control switch 73, and the eighth control switch 74 can be obtained. Then, according to the switching control period and the switching conduction period indicated by the low-voltage control signals, the target phase-shift angle can be determined using a preset relationship. Then, within the preset phase-shift angle range, the low-voltage control signals corresponding to the fifth control switch 71, the sixth control switch 72, the seventh control switch 73, and the eighth control switch 74 can be phase-shifted respectively according to the target phase-shift angle to adjust the phase-shift angles of the low-voltage control signals corresponding to the fifth control switch 71, the sixth control switch 72, the seventh control switch 73, and the eighth control switch 74. And according to the adjusted low-voltage control signals corresponding to the fifth control switch 71, the sixth control switch 72, the seventh control switch 73, and the eighth control switch 74, the fifth control switch 71, the sixth control switch 72, the seventh control switch 73, and the eighth control switch 74 can be controlled respectively, so that the third bridge arm and the fourth bridge arm lead the first bridge arm by the target phase-shift angle.

[0062] In order to further reduce the current stress on the low-voltage side of the phase-shifted full-bridge converter, the duty cycle of the second control switch can be made greater than 50% (i.e., the duty cycle of the low-voltage side of the phase-shifted full-bridge converter is greater than 50%). In this way, at a certain moment, the fifth control switch 71 and the sixth control switch 72 will conduct simultaneously, and / or the seventh control switch 73 and the eighth control switch 74 will conduct simultaneously. At this time, the low-voltage side of the phase-shifted full-bridge converter will present a short-circuit state, and the energy of the transformer cannot be transmitted to the low-voltage side of the transformer, thus suppressing the increase in the peak-to-peak value of the current on the low-voltage side of the phase-shifted full-bridge converter and reducing the current stress on the low-voltage side of the phase-shifted full-bridge converter. Before the low-voltage control signals are phase-shifted according to the target phase-shift angle, there will be a situation where the current on the low-voltage side of the phase-shifted full-bridge converter is relatively large due to the presence of the third capacitor 3 when the low-voltage side of the phase-shifted full-bridge converter is in a short-circuit state, resulting in a still relatively large peak-to-peak value of the current on the low-voltage side of the phase-shifted full-bridge converter and affecting the current stress on the low-voltage side of the phase-shifted full-bridge converter. After the low-voltage control signals are phase-shifted according to the target phase-shift angle, the maximum current on the low-voltage side of the phase-shifted full-bridge converter can appear in the time period when the low-voltage side of the phase-shifted full-bridge converter is not in a short-circuit state, thus reducing the peak-to-peak value of the current on the low-voltage side of the phase-shifted full-bridge converter and further reducing the current stress on the low-voltage side of the phase-shifted full-bridge converter.

[0063] In summary, the present disclosure first obtains control parameters of low-voltage control signals corresponding to a plurality of second control switches, where the control parameters include a switch control period and a switch conduction period, and determines a target phase-shift angle of a low-voltage module according to the switch control period and the switch conduction period. Then, the phase angle of the low-voltage control signal is adjusted according to the target phase-shift angle, and the plurality of second control switches are controlled according to the adjusted low-voltage control signal, and the plurality of first control switches are controlled according to a specified duty cycle, so that the phase-shifted full-bridge converter outputs a target voltage. The present disclosure can determine the target phase-shift angle according to the control parameters of the low-voltage control signal on the low-voltage side, and dynamically adjust the phase angle of the low-voltage side according to the target phase-shift angle, which can reduce the current stress on the low-voltage side while ensuring the load-carrying capacity of the phase-shifted full-bridge converter, reduce the heat generation of the second control switches on the low-voltage side, so that the phase-shifted full-bridge converter can be applied to more application scenarios, and improve the practicability, expandability and safety of the phase-shifted full-bridge converter.

[0064] Figure 5 is a block diagram of a control device of a phase-shifted converter shown according to an exemplary embodiment. As Figure 5 shown, the control device 700 of the phase-shifted full-bridge converter may include: a processor 701, a memory 702. The control device 700 of the phase-shifted full-bridge converter may further include one or more of a multimedia component 703, an input / output (I / O) interface 704, and a communication component 705.

[0065] Among them, the processor 701 is used to control the overall operation of the control device 700 of the phase-shifted full-bridge converter to complete all or part of the steps in the above-mentioned control method of the phase-shifted full-bridge converter. The memory 702 is used to store various types of data to support the operation of the control device 700 of the phase-shifted full-bridge converter. These data may include, for example, instructions for any application program or method operating on the control device 700 of the phase-shifted full-bridge converter, as well as application program-related data, such as contact data, sent and received messages, pictures, audio, video, and so on. The memory 702 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic memory, flash memory, magnetic disk or optical disc. The multimedia component 703 may include a screen and an audio component. Among them, the screen may be a touch screen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signal may be further stored in the memory 702 or sent through the communication component 705. The audio component also includes at least one speaker for outputting audio signals. The I / O interface 704 provides an interface between the processor 701 and other interface modules, and the above other interface modules may be a keyboard, a mouse, buttons, etc. These buttons may be virtual buttons or physical buttons. The communication component 705 is used for wired or wireless communication between the control device 700 of the phase-shifted full-bridge converter and other devices. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G, 4G, NB-IOT, eMTC, or other 5G, etc., or a combination of one or more of them, is not limited herein. Therefore, the corresponding communication component 705 may include: a Wi-Fi module, a Bluetooth module, an NFC module, and so on.

[0066] In an exemplary embodiment, the control device 700 of the phase-shifted full-bridge converter can be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors or other electronic components, and is used to execute the above-mentioned control method of the phase-shifted full-bridge converter.

[0067] In another exemplary embodiment, a computer-readable storage medium including program instructions is further provided. When the program instructions are executed by a processor, the steps of the above-mentioned control method of the phase-shifted full-bridge converter are implemented. For example, the computer-readable storage medium can be the above-mentioned memory 702 including program instructions, and the above-mentioned program instructions can be executed by the processor 701 of the control device 700 of the phase-shifted full-bridge converter to complete the above-mentioned control method of the phase-shifted full-bridge converter.

[0068] Figure 6 is a block diagram of a phase-shifted converter shown according to an exemplary embodiment. As Figure 6 shown, the phase-shifted full-bridge converter 200 includes a high-voltage module 6, a low-voltage module 7, a transformer 8, and Figure 5 the control device 700 shown. The high-voltage module 6 is connected to the low-voltage module 7 through the transformer 8. The high-voltage module 6 includes a plurality of first control switches, the low-voltage module 7 includes a plurality of second control switches, and the control device 700 is respectively connected to the high-voltage module 1 and the low-voltage module 2.

[0069] Figure 7 is a block diagram of a control system of a phase-shifted full-bridge converter shown according to an exemplary embodiment. As Figure 7 shown, the control system 300 includes the phase-shifted full-bridge converter 200 and Figure 5 the control device 700 shown. The phase-shifted full-bridge converter 200 is connected to the control device 700.

[0070] In summary, the present disclosure first obtains the control parameters of the low-voltage control signals corresponding to multiple second control switches, where the control parameters include the switch control period and the switch conduction period, and determines the target phase-shift angle of the low-voltage module according to the switch control period and the switch conduction period. Then, the phase angle of the low-voltage control signal is adjusted according to the target phase-shift angle, and the multiple second control switches are controlled according to the adjusted low-voltage control signal, and the multiple first control switches are controlled according to a specified duty cycle, so that the phase-shifted full-bridge converter outputs a target voltage. The present disclosure can determine the target phase-shift angle through the control parameters of the low-voltage control signals on the low-voltage side, and dynamically adjust the phase angle of the low-voltage side according to the target phase-shift angle. In this way, while ensuring the load-carrying capacity of the phase-shifted full-bridge converter, the current stress on the low-voltage side can be reduced, the heat generation of the second control switches on the low-voltage side can be reduced, so that the phase-shifted full-bridge converter can be applied to more application scenarios, and the practicability, expandability and safety of the phase-shifted full-bridge converter are improved.

[0071] In another exemplary embodiment, a computer program product is further provided. The computer program product includes a computer program that can be executed by a programmable device, and the computer program has a code portion for executing the above control method of the phase-shifted full-bridge converter when executed by the programmable device.

[0072] The preferred embodiments of the present disclosure have been described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0073] In addition, it should be noted that, in the above specific embodiments, the various specific technical features described can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present disclosure does not separately describe various possible combination manners.

[0074] In addition, any combination can be made between various different embodiments of the present disclosure as long as it does not violate the idea of the present disclosure, and it should also be regarded as the content disclosed by the present disclosure.

Claims

1. A control method for a phase-shifted full-bridge converter, characterized in that The phase-shifted full-bridge converter includes a high-voltage module, a low-voltage module, and a transformer. The high-voltage module is connected to the low-voltage module through the transformer. The high-voltage module includes a first bridge arm and a second bridge arm, and the low-voltage module includes a third bridge arm and a fourth bridge arm. A plurality of first control switches are respectively arranged on the first bridge arm and the second bridge arm, and a plurality of second control switches are respectively arranged on the third bridge arm and the fourth bridge arm. The method includes: Obtain the control parameters of the low-voltage control signals corresponding to the plurality of second control switches. The control parameters include a switching control period and a switching conduction period. Determine the target phase-shift angle of the low-voltage module according to the switching control period and the switching conduction period. Adjust the phase angle of the low-voltage control signal according to the target phase-shift angle, control the plurality of second control switches according to the adjusted low-voltage control signal, and control the plurality of first control switches according to a specified duty cycle, so that the phase-shifted full-bridge converter outputs a target voltage. The adjusting the phase angle of the low-voltage control signal according to the target phase-shift angle and controlling the plurality of second control switches according to the adjusted low-voltage control signal includes: Phase-shift the low-voltage control signal according to the target phase-shift angle to adjust the phase-shift angle of the low-voltage control signal and generate the adjusted low-voltage control signal. Control the plurality of second control switches according to the adjusted low-voltage control signal, so that the third bridge arm and the fourth bridge arm lead the target phase-shift angle with respect to the first bridge arm or the second bridge arm.

2. The method according to claim 1, characterized in that, The determining the target phase-shift angle of the low-voltage module according to the switching control period and the switching conduction period includes: Determine the target phase-shift angle based on a preset relationship according to the switching control period and the switching conduction period. The preset relationship is to determine a target period parameter according to the switching control period and the switching conduction period, and determine the target phase-shift angle according to the target period parameter and the switching control period. The target period parameter is used to indicate the difference between the switching conduction period and the switching off period.

3. The method according to claim 1, wherein The controlling the plurality of second control switches according to the adjusted low-voltage control signal includes: Adjust the adjusted low-voltage control signal according to a preset duty cycle to obtain a target low-voltage control signal. Control the plurality of second control switches according to the target low-voltage control signal, so that the third bridge arm and the fourth bridge arm lead the target phase-shift angle with respect to the first bridge arm or the second bridge arm, and make the plurality of second control switches conduct according to the preset duty cycle.

4. The method according to claim 3, wherein The specified duty cycle is 50%, and the preset duty cycle is greater than or equal to the specified duty cycle.

5. The method according to any one of claims 1-4, characterized in that, The first bridge arm includes a first control switch and a second control switch connected to the first control switch. The second bridge arm includes a third control switch and a fourth control switch connected to the third control switch. The third bridge arm includes a fifth control switch and a sixth control switch connected to the fifth control switch. The fourth bridge arm includes a seventh control switch and an eighth control switch connected to the seventh control switch.

6. The method according to claim 5, characterized in that, The phase-shifted full-bridge converter further includes a first capacitor, a second capacitor, a third capacitor, a first inductor, and a second inductor. The first end of the first control switch is respectively connected to the first end of the third control switch and the first end of the first capacitor. The second end of the second control switch is respectively connected to the second end of the fourth control switch and the second end of the first capacitor. The second end of the first control switch is respectively connected to the first end of the second control switch and the first end of the second capacitor. The second end of the second capacitor is connected to the first end of the first inductor. The second end of the first inductor is connected to the first end of the high-voltage side of the transformer. The second end of the third control switch is respectively connected to the first end of the fourth control switch and the second end of the high-voltage side of the transformer. The first end of the fifth control switch is respectively connected to the first end of the seventh control switch, the first end of the third capacitor, and the first end of the second inductor. The second end of the sixth control switch is respectively connected to the second end of the eighth control switch and the second end of the third capacitor. The second end of the fifth control switch is respectively connected to the first end of the sixth control switch and the first end of the low-voltage side of the transformer. The second end of the seventh control switch is respectively connected to the first end of the eighth control switch and the second end of the low-voltage side of the transformer.

7. A control device for a phase-shifted full-bridge converter, characterized in that, The control device includes: a memory on which a computer program is stored; a processor for executing the computer program in the memory to implement the steps of the method according to any one of claims 1-6.

8. A phase-shifted full-bridge converter, characterized in that The phase-shifted full-bridge converter includes a high-voltage module, a low-voltage module, a transformer, and the control device according to claim 7. The high-voltage module is connected to the low-voltage module through the transformer. The control device is respectively connected to the high-voltage module and the low-voltage module.

9. A control system for a phase-shifted full-bridge converter, characterized in that The control system includes a phase-shifted full-bridge converter and the control device according to claim 7. The phase-shifted full-bridge converter is connected to the control device.

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