PFC-LLC peak current protection circuit with dynamic compensation

Abstract

The application relates to a PFC-LLC peak current protection circuit with dynamic compensation, which comprises a half-bridge LLC and resonant capacitor voltage sampling circuit module for sampling a voltage signal on an LLC resonant capacitor and converting the voltage signal into a detection voltage sampling signal that can be processed by a DSP chip; a first input end of the half-bridge LLC and resonant capacitor voltage sampling circuit module is connected with a PFC voltage boosting circuit module, and a first output end of the half-bridge LLC and resonant capacitor voltage sampling circuit module is connected with a DSP chip control module; a first output end of the DSP chip control module is connected with the PFC voltage boosting circuit module, and a second output end of the DSP chip control module is connected with a second input end of the half-bridge LLC and resonant capacitor voltage sampling circuit module; the scheme provided by the application can establish a state correlation and cooperative control mechanism between the PFC and the LLC, meet power supply dynamic output indexes, reduce output voltage ripple in the power supply dynamic working process, and simultaneously perform resonant cavity peak current detection and protection.

Description

Technical Field

[0001] This application relates to the field of power supply protection technology, and in particular to a PFC-LLC peak current protection circuit with dynamic compensation. Background Technology

[0002] Currently, in medium- and high-power power supply systems, the architecture combining digital power factor correction (PFC) with a half-bridge LLC resonant converter is widely used. As the power density requirements of power supply systems continue to increase, power supply designs tend to reduce the capacitance of the voltage bus (VBUS) output capacitor and the LLC output capacitor to reduce size and cost.

[0003] In traditional architectures, the VBUS voltage output by the PFC module is not directly related to the actual operating state of the subsequent LLC resonant cavity. When the load transitions, such as from light load to heavy load, the LLC switching frequency changes from high to low, and the gain increases. If the VBUS voltage remains constant, the LLC output voltage will exhibit a significant "drop-in" phenomenon. Conversely, when transitioning from heavy load to light load, the LLC switching frequency changes from low to high, and the gain decreases, similarly causing overshoot in the LLC output voltage. This dynamic process of load transition leads to a significant increase in output voltage ripple. To meet dynamic performance requirements, traditional solutions often require increasing the output capacitor capacity, thereby increasing system size and cost. Furthermore, PFC control and LLC control typically operate independently, lacking a coordinated adjustment mechanism based on load conditions. When the LLC operating point deviates from the resonant point, system efficiency decreases, dynamic response capability further deteriorates, and the overall performance and reliability of the power supply are affected.

[0004] Secondly, traditional LLC resonant cavities typically use current transformers (CTs) to detect the resonant current in order to achieve overcurrent protection, but the CTs themselves occupy a large space, which is not conducive to the miniaturization design of power supplies.

[0005] Therefore, there is an urgent need for a technical solution that can sense the LLC resonant state in real time, dynamically adjust the PFC output voltage, and achieve an efficient and compact peak current protection mechanism. Summary of the Invention

[0006] To address or partially address the problems existing in related technologies, this application provides a PFC-LLC peak current protection circuit with dynamic compensation, aiming to solve the problem of poor dynamic response and large output capacitance caused by the lack of coordination between PFC and LLC control in existing medium and high power power supply systems.

[0007] This application provides a PFC-LLC peak current protection circuit with dynamic compensation, including: EMI filter rectifier circuit module, PFC boost circuit module, DSP chip control module, and half-bridge LLC and resonant capacitor voltage sampling circuit module; The half-bridge LLC and resonant capacitor voltage sampling circuit module is used to sample the voltage signal on the LLC resonant capacitor and convert it into a detection voltage sampling signal that can be processed by the DSP chip. The first input terminal of the half-bridge LLC and resonant capacitor voltage sampling circuit module is connected to the PFC boost circuit module, and the first output terminal of the half-bridge LLC and resonant capacitor voltage sampling circuit module is connected to the DSP chip control module; the first output terminal of the DSP chip control module is connected to the PFC boost circuit module, and the second output terminal of the DSP chip control module is connected to the second input terminal of the half-bridge LLC and resonant capacitor voltage sampling circuit module. When the half-bridge LLC resonant converter transitions from light load to heavy load or from heavy load to light load, the half-bridge LLC and resonant capacitor voltage sampling circuit module acquires and detects the voltage sampling signal, which is then sent to the DSP chip control module. The signal is compared with the set reference value, and the DSP chip control module takes action on the PFC boost circuit module or the half-bridge LLC and resonant capacitor voltage sampling circuit module based on the result.

[0008] Optional, the half-bridge LLC and resonant capacitor voltage sampling circuit module includes: Switching circuit, resonant circuit, transformer, rectifier and filter circuit, and resonant capacitor voltage sampling circuit; The switching circuit is connected to the PFC boost circuit module and the DSP chip control module respectively; the switching circuit, resonant circuit, transformer and rectifier filter circuit are connected in sequence; the resonant capacitor voltage sampling circuit is connected to both ends of the resonant capacitor in the resonant circuit. The resonant capacitor voltage sampling circuit is used to collect the voltage signal on the resonant capacitor and convert it into a detection voltage sampling signal that can be processed by the DSP chip.

[0009] Optionally, the resonant capacitor voltage sampling circuit includes: Second capacitor C2, third capacitor C3, first operational amplifier U1, first resistor R1, second resistor R2, third resistor R3, fourth resistor R4, fifth resistor R5 and sixth resistor R6; One end of the resonant capacitor is connected to the primary side ground terminal, and the other end of the resonant capacitor is connected to one end of the primary side of the transformer, the second capacitor C2, and the first resistor R1. The other end of the second capacitor C2 is connected to the third capacitor C3, the other end of the first resistor R1, the second resistor R2, and the fourth resistor R4. The other ends of the third capacitor C3 and the second resistor R2 are connected to the primary side ground terminal. The other end of the fourth resistor R4 is connected to the sixth resistor R6 and the non-inverting input terminal of the first operational amplifier U1. The other end of the sixth resistor R6 is connected to the primary side ground terminal. One end of the third resistor R3 is connected to the primary side ground terminal, and the other end of the third resistor R3 is connected to the fifth resistor R5 and the inverting input terminal of the first operational amplifier U1. The other end of the fifth resistor R5 is connected to the output terminal of the first operational amplifier U1. The output terminal of the first operational amplifier U1 outputs a voltage sampling signal, which is sent to the DSP chip control module.

[0010] Optionally, the resonant circuit includes: First inductor L1, first capacitor C1; One end of the first inductor L1 is connected to the switching circuit, and the other end of the first inductor L1 is connected to one end of the primary side of the transformer; one end of the first capacitor C1 is connected to the other end of the primary side of the transformer, and the other end of the first capacitor C1 is connected to the primary side grounding terminal.

[0011] Optionally, the switching circuit includes: First switch Q1, second switch Q2; The drain of the first switch Q1 is connected to the voltage bus of the PFC boost circuit module, the gate of the first switch Q1 is connected to the DSP chip control module, the source of the first switch Q1 is connected to the drain of the second switch Q2 and the resonant circuit; the gate of the second switch Q2 is connected to the DSP chip control module, and the gate of the second switch Q2 is connected to the primary side ground terminal.

[0012] Optionally, the rectifier filter circuit includes: First diode D1, second diode D2, fourth capacitor C4; The anode of the first diode D1 is connected to one end of the secondary side of the transformer; the anode of the second diode D2 is connected to the other end of the secondary side of the transformer; the center tap of the secondary side of the transformer is connected to the fourth capacitor C4 and the secondary ground terminal; the cathode of the first diode D1 is connected to the cathode of the second diode D2 and the other end of the fourth capacitor C4.

[0013] Optionally, when the half-bridge LLC resonant converter transitions from light load to heavy load, the detection voltage sampling signal acquired by the half-bridge LLC and resonant capacitor voltage sampling circuit module increases from small to large and is sent to the DSP chip control module. If it is less than the set reference value 1, the bus voltage at the output terminal of the PFC boost circuit module remains unchanged; if the sampling signal is greater than the set reference value 1 but less than the set reference value 2, the VBUS voltage at the output terminal of the PFC boost circuit module also remains unchanged; if the sampling signal is greater than the set reference value 2 but less than the set reference value 3, the DSP chip control module increases the bus voltage of the PFC boost circuit module by sampling the state of the half-bridge LLC resonant circuit to achieve dynamic compensation; if the sampling signal is greater than the set reference value 3, the DSP chip control module controls the switching transistor signal of the half-bridge LLC and resonant capacitor voltage sampling circuit module to turn off the half-bridge LLC resonant circuit to achieve peak current protection.

[0014] Optionally, when the half-bridge LLC transitions from heavy load to light load, the detection voltage sampling signal acquired by the half-bridge LLC and resonant capacitor voltage sampling circuit module decreases. If the detection voltage sampling signal is less than the set reference value 3 but greater than the set reference value 2, the bus voltage at the output terminal of the PFC boost circuit module remains unchanged. If the sampling signal is less than the set reference value 2 but greater than the set reference value 1, the bus voltage at the output terminal of the PFC boost circuit module remains unchanged. If the sampling signal is less than the set reference value 1, the DSP chip control module reduces the bus voltage of the PFC boost circuit module by sampling the state of the half-bridge LLC resonant circuit, thereby achieving dynamic compensation.

[0015] Optionally, the first switch Q1 and the second switch Q2 are NMOS transistors, with the control terminal of the first switch being the gate and the control terminal of the second switch being the gate.

[0016] Optionally, the first diode D1 and the second diode D2 can also be silicon MOS or silicon carbide MOS switching devices.

[0017] The technical solution provided in this application may include the following beneficial effects: By acquiring the LLC resonant capacitor voltage signal in real time, and cooperating with the DSP chip to accurately sense the load transition state, and dynamically adjusting the PFC output bus voltage, a state correlation and collaborative control mechanism between the PFC and LLC is established. This reduces the output voltage ripple during the dynamic operation of medium and high power supplies. Under the premise of meeting the same dynamic indicators, the capacitance of the VBUS output capacitor and the LLC output capacitor is reduced, which is conducive to the miniaturization, weight reduction and cost reduction of the power supply system. At the same time, the same resonant capacitor voltage sampling signal can also be used for resonant cavity peak current detection and protection. When the sampling signal exceeds the set protection threshold, the LLC switch is turned off to achieve fast and reliable overcurrent protection.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0019] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0020] Figure 1 This is a schematic diagram of the structure of a PFC-LLC peak current protection circuit with dynamic compensation shown in an embodiment of this application; Figure 2 This is a schematic diagram showing the connection of the half-bridge LLC and resonant capacitor voltage sampling circuit module of the PFC-LLC peak current protection circuit with dynamic compensation, as illustrated in an embodiment of this application. Figure 3 This is a schematic diagram of the half-bridge LLC and resonant capacitor voltage sampling circuit module of the PFC-LLC peak current protection circuit with dynamic compensation, as shown in the embodiments of this application.

[0021] Figure reference numerals: 100-EMI filter and rectifier module, 200-PFC boost circuit module, 300-half-bridge LLC and resonant capacitor voltage sampling circuit module, 400-DSP chip control module. Detailed Implementation

[0022] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0023] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0024] In traditional architectures, the VBUS voltage output by the PFC module is not directly related to the actual operating state of the subsequent LLC resonant cavity. When the load transitions, such as from light load to heavy load, the LLC switching frequency changes from high to low, and the gain increases. If the VBUS voltage remains constant, the LLC output voltage will exhibit a significant "drop-in" phenomenon. Conversely, when transitioning from heavy load to light load, the LLC switching frequency changes from low to high, and the gain decreases, similarly causing overshoot in the LLC output voltage. This dynamic process of load transition leads to a significant increase in output voltage ripple. To meet dynamic performance requirements, traditional solutions often require increasing the output capacitor capacity, thereby increasing system size and cost. Furthermore, PFC control and LLC control typically operate independently, lacking a coordinated adjustment mechanism based on load conditions. When the LLC operating point deviates from the resonant point, system efficiency decreases, and dynamic response capability further deteriorates, affecting the overall performance and reliability of the power supply. Secondly, traditional LLC resonant cavities typically use current transformers (CTs) to detect the resonant current for overcurrent protection, but the CTs themselves occupy a large space, which is detrimental to power supply miniaturization design.

[0025] To address the aforementioned issues, this application provides a PFC-LLC peak current protection circuit with dynamic compensation. This circuit can accurately sense the load transition state by real-time acquisition of the LLC resonant capacitor voltage signal, in conjunction with a DSP chip, and dynamically adjust the PFC output bus voltage. It establishes a state correlation and collaborative control mechanism between the PFC and LLC, reducing the output voltage ripple during the dynamic operation of medium-to-high power supplies. While meeting the same dynamic performance indicators, it reduces the capacitance of the VBUS output capacitor and the LLC output capacitor, which is beneficial for miniaturization, weight reduction, and cost reduction of the power supply system. Simultaneously, the same resonant capacitor voltage sampling signal can also be used for resonant cavity peak current detection and protection. When the sampling signal exceeds a set protection threshold, the LLC switch is turned off, achieving fast and reliable overcurrent protection.

[0026] The technical solutions of the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0027] Figure 1 This is a schematic diagram of the structure of a PFC-LLC peak current protection circuit with dynamic compensation, as shown in an embodiment of this application.

[0028] See Figure 1 A PFC-LLC peak current protection circuit with dynamic compensation includes: EMI filter and rectifier module 100, PFC boost circuit module 200, half-bridge LLC and resonant capacitor voltage sampling circuit module 300, and DSP chip control module 400. The input terminal of the EMI filter and rectifier module 100 is connected to the power input. The output terminal of the EMI filter and rectifier module 100 is connected to the first input terminal of the PFC boost circuit module 200, and the output voltage of the EMI filter and rectifier module 100 is VIN. The output terminal of the PFC boost circuit module 200 is connected to the first input terminal of the half-bridge LLC and resonant capacitor voltage sampling circuit module 300, and the output bus voltage of the PFC boost circuit module 200 is VBUS. The voltage sampling signal output terminal of the half-bridge LLC and resonant capacitor voltage sampling circuit module 300 is connected to the DSP chip control module 400. The first and second switching transistor control signal terminals of the half-bridge LLC and resonant capacitor voltage sampling circuit module 300 are respectively connected to the second output terminal of the DSP chip control module 400. The first output terminal of the DSP chip control module 400 is connected to the PFC boost circuit module 200.

[0029] The half-bridge LLC and resonant capacitor voltage sampling circuit module includes a switching circuit, a resonant circuit, a transformer, a rectifier and filter circuit, and a resonant capacitor voltage sampling circuit. The switching circuit is connected to the PFC boost circuit module and the DSP chip control module respectively. The switching circuit, resonant circuit, transformer, and rectifier and filter circuit are connected in sequence. The resonant capacitor voltage sampling circuit is connected across the resonant capacitor in the resonant circuit. The resonant capacitor voltage sampling circuit is used to collect the voltage signal on the resonant capacitor and convert it into a detection voltage sampling signal that can be processed by the DSP chip.

[0030] Specifically, such as Figure 3As shown, the half-bridge LLC and resonant capacitor voltage sampling circuit module includes a first switch Q1, a second switch Q2, a first inductor L1, a first transformer T1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first diode D1, a second diode D2, a first operational amplifier U1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6; the drain of the first switch Q1 is connected to the VBUS bus terminal, and the gate of the first switch Q1... The source of the first switching transistor Q1 is connected to the drain of the second switching transistor Q2 and the first inductor L1; the gate of the second switching transistor Q2 is connected to the DSP chip control module, and the gate of the second switching transistor Q2 is connected to the primary side ground terminal; the other end of the first inductor L1 is connected to one end of the primary side of the first transformer T1, and the other end of the primary side of the first transformer T1 is connected to the first capacitor C1, the second capacitor C2 and the first resistor R1 respectively; the other end of the first capacitor C1 is connected to the primary side ground terminal; the other end of the second capacitor C2 is connected to... Connect the third capacitor C3, the other end of the first resistor R1, the second resistor R2, and the fourth resistor R4; connect the third capacitor C3 and the other end of the second resistor R2 to the primary side ground terminal; connect the other end of the fourth resistor R4 to the sixth resistor R6 and the non-inverting input terminal of the first operational amplifier U1; connect the other end of the sixth resistor R6 to the primary side ground terminal; connect one end of the third resistor R3 to the primary side ground terminal; connect the other end of the third resistor R3 to the fifth resistor R5 and the inverting input terminal of the first operational amplifier U1; connect the other end of the fifth resistor R5 to the output terminal of the first operational amplifier U1; output the voltage sampling signal from the output terminal of the first operational amplifier U1, and send the voltage sampling signal to the DSP chip control module; connect one end of the secondary side of the first transformer T1 to the anode of the first diode D1; connect the other end of the secondary side of the first transformer T1 to the anode of the second diode D2; connect the center tap of the secondary side of the first transformer T1 to the fourth capacitor C4 and the secondary side ground terminal; connect the cathode of the first diode D1 to the cathode of the second diode D2 and the other end of the fourth capacitor C4.

[0031] During dynamic testing, the DSP chip control module 400 receives the magnitude of the detection voltage sampling signal Cr_ADC collected by the half-bridge LLC and resonant capacitor voltage sampling circuit module 300. The DSP chip control module 400 adjusts the output bus voltage VBUS of the PFC boost circuit module 200 for dynamic compensation. When the DSP chip control module 400 detects that the detection voltage sampling signal Cr_ADC is too large, the DSP chip control module 400 turns off the first switch control signal terminal G1 and the second switch control signal terminal G2 of the half-bridge LLC and resonant capacitor voltage sampling circuit module 300 to achieve peak current protection.

[0032] Specifically, when the half-bridge LLC transitions from light load to heavy load, the detection voltage sampling signal Cr_ADC of the half-bridge LLC and resonant capacitor voltage sampling circuit module 300 increases from small to large. This sampling signal is sent to the DSP chip control module 400 for comparison. If it is less than the set reference value 1, the VBUS voltage at the output terminal of the PFC boost circuit module 200 remains unchanged. If the sampling signal is greater than the set reference value 1 and less than the set reference value 2, the set reference value 1 and the set reference value 2 serve as a hysteresis interval, and the VBUS voltage at the output terminal of the PFC boost circuit module 200 remains unchanged. If the sampling signal is greater than the set reference value 2 and less than the set reference value 3, the DSP chip control module 400 increases the VBUS voltage of the PFC boost circuit module by sampling the LLC resonant state to achieve dynamic compensation. If the sampling signal is greater than the set reference value 3, the DSP chip control module 400 sends G1 signals to control the first switch Q1 and the second switch Q2 of the half-bridge LLC and resonant capacitor voltage sampling circuit module 300, shutting down the half-bridge LLC resonant circuit and achieving peak current protection.

[0033] Specifically, when the half-bridge LLC transitions from heavy load to light load, the detection voltage sampling signal Cr_ADC of the half-bridge LLC and resonant capacitor voltage sampling circuit module 300 decreases from large to small. This sampling signal is sent to the DSP chip control module 400 for comparison. If the sampling signal is less than the set reference value 3 and greater than the set reference value 2, the VBUS voltage at the output terminal of the PFC boost circuit module 200 remains unchanged. If the sampling signal is less than the set reference value 2 and greater than the set reference value 1, the VBUS voltage at the output terminal of the PFC boost circuit module 200 remains unchanged. If the sampling signal is less than the set reference value 1, the DSP chip control module 400 reduces the VBUS voltage of the PFC boost circuit module by sampling the LLC resonant state, thereby achieving dynamic compensation.

[0034] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A PFC-LLC peak current protection circuit with dynamic compensation, comprising an EMI filter rectifier circuit module, a PFC boost circuit module, and a DSP chip control module, characterized in that, Also includes: Half-bridge LLC and resonant capacitor voltage sampling circuit module; The half-bridge LLC and resonant capacitor voltage sampling circuit module is used to sample the voltage signal on the LLC resonant capacitor and convert it into a detection voltage sampling signal that can be processed by the DSP chip. The first input terminal of the half-bridge LLC and resonant capacitor voltage sampling circuit module is connected to the PFC boost circuit module, and the first output terminal of the half-bridge LLC and resonant capacitor voltage sampling circuit module is connected to the DSP chip control module. The first output terminal of the DSP chip control module is connected to the PFC boost circuit module, and the second output terminal of the DSP chip control module is connected to the second input terminal of the half-bridge LLC and resonant capacitor voltage sampling circuit module. When the half-bridge LLC resonant converter transitions from light load to heavy load or from heavy load to light load, the half-bridge LLC and resonant capacitor voltage sampling circuit module acquires and detects the voltage sampling signal, which is then sent to the DSP chip control module for comparison with a set reference value. Based on the comparison result, the DSP chip control module activates the PFC boost circuit module or the half-bridge LLC and resonant capacitor voltage sampling circuit module.

2. The PFC-LLC peak current protection circuit with dynamic compensation according to claim 1, characterized in that, The half-bridge LLC and resonant capacitor voltage sampling circuit module includes: Switching circuit, resonant circuit, transformer, rectifier and filter circuit, and resonant capacitor voltage sampling circuit; The switching circuit is connected to the PFC boost circuit module and the DSP chip control module respectively. The switching circuit, resonant circuit, transformer, and rectifier filter circuit are connected in sequence; The resonant capacitor voltage sampling circuit is connected across the resonant capacitor in the resonant circuit. The resonant capacitor voltage sampling circuit is used to collect the voltage signal on the resonant capacitor and convert it into a detection voltage sampling signal that can be processed by the DSP chip.

3. The PFC-LLC peak current protection circuit with dynamic compensation according to claim 2, characterized in that, The resonant capacitor voltage sampling circuit includes: Second capacitor C2, third capacitor C3, first operational amplifier U1, first resistor R1, second resistor R2, third resistor R3, fourth resistor R4, fifth resistor R5 and sixth resistor R6; One end of the resonant capacitor is connected to the primary side ground terminal, and the other end of the resonant capacitor is connected to one end of the primary side of the transformer, the second capacitor C2 and the first resistor R1 respectively. The other end of the second capacitor C2 is connected to the third capacitor C3, the other end of the first resistor R1, the second resistor R2, and the fourth resistor R4, respectively; The other end of the third capacitor C3 and the second resistor R2 is connected to the primary side ground terminal; The other end of the fourth resistor R4 is connected to the sixth resistor R6 and the non-inverting input of the first operational amplifier U1, respectively. The other end of the sixth resistor R6 is connected to the primary side ground terminal; One end of the third resistor R3 is connected to the primary side ground terminal, and the other end of the third resistor R3 is connected to the fifth resistor R5 and the inverting input terminal of the first operational amplifier U1, respectively. The other end of the fifth resistor R5 is connected to the output terminal of the first operational amplifier U1; The first operational amplifier U1 outputs a voltage sampling signal, which is then sent to the DSP chip control module.

4. The PFC-LLC peak current protection circuit with dynamic compensation according to claim 2, characterized in that, The resonant circuit includes: First inductor L1, first capacitor C1; One end of the first inductor L1 is connected to the switching circuit, and the other end of the first inductor L1 is connected to one end of the primary side of the transformer. One end of the first capacitor C1 is connected to the other end of the primary side of the transformer, and the other end of the first capacitor C1 is connected to the primary side grounding terminal.

5. The PFC-LLC peak current protection circuit with dynamic compensation according to claim 2, characterized in that, The switching circuit includes: First switch Q1, second switch Q2; The drain of the first switch Q1 is connected to the PFC boost circuit module, the gate of the first switch Q1 is connected to the DSP chip control module, and the source of the first switch Q1 is connected to the drain of the second switch Q2 and the resonant circuit. The gate of the second switch Q2 is connected to the DSP chip control module, and the gate of the second switch Q2 is connected to the primary side ground terminal.

6. The PFC-LLC peak current protection circuit with dynamic compensation according to claim 2, characterized in that, The rectifier filter circuit includes: First diode D1, second diode D2, fourth capacitor C4; The anode of the first diode D1 is connected to one end of the secondary side of the transformer. The anode of the second diode D2 is connected to the other end of the secondary side of the transformer; The center tap on the secondary side of the transformer is connected to the fourth capacitor C4 and the secondary side grounding terminal; The cathode of the first diode D1 is connected to the cathode of the second diode D2 and the other end of the fourth capacitor C4.

7. The PFC-LLC peak current protection circuit with dynamic compensation according to claim 1, characterized in that: When the half-bridge LLC resonant converter transitions from light load to heavy load, the detection voltage sampling signal acquired by the half-bridge LLC and resonant capacitor voltage sampling circuit module increases from small to large and is sent to the DSP chip control module. If it is less than the set reference value 1, the bus voltage at the output terminal of the PFC boost circuit module remains unchanged; if the sampling signal is greater than the set reference value 1 but less than the set reference value 2, the VBUS voltage at the output terminal of the PFC boost circuit module also remains unchanged; if the sampling signal is greater than the set reference value 2 but less than the set reference value 3, the DSP chip control module increases the bus voltage of the PFC boost circuit module by sampling the state of the half-bridge LLC resonant circuit to achieve dynamic compensation; if the sampling signal is greater than the set reference value 3, the DSP chip control module sends a switching signal to control the switching transistors of the half-bridge LLC and resonant capacitor voltage sampling circuit module, turning off the half-bridge LLC resonant circuit to achieve peak current protection.

8. The PFC-LLC peak current protection circuit with dynamic compensation according to claim 1, characterized in that: When the half-bridge LLC transitions from heavy load to light load, the detection voltage sampling signal acquired by the half-bridge LLC and resonant capacitor voltage sampling circuit module decreases. If the detection voltage sampling signal is less than the set reference value 3 but greater than the set reference value 2, the bus voltage at the output terminal of the PFC boost circuit module remains unchanged. If the sampling signal is less than the set reference value 2 but greater than the set reference value 1, the bus voltage at the output terminal of the PFC boost circuit module remains unchanged. If the sampling signal is less than the set reference value 1, the DSP chip control module reduces the bus voltage of the PFC boost circuit module by sampling the state of the half-bridge LLC resonant circuit, thereby achieving dynamic compensation.

9. The PFC-LLC peak current protection circuit with dynamic compensation according to claim 5, characterized in that: The first switch Q1 and the second switch Q2 are NMOS transistors, and the control terminal of the first switch is the gate, and the control terminal of the second switch is the gate.

10. The PFC-LLC peak current protection circuit with dynamic compensation according to claim 6, characterized in that: The first diode D1 and the second diode D2 can also be silicon MOS or silicon carbide MOS switching devices.

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