LLC resonant power supply integrated with over-current protection

Abstract

The utility model discloses an LLC resonant power supply integrated with overcurrent protection, and relates to the technical field of power electronics. The resonant power supply comprises an overcharge current suppression module, a power supply module, a PFC module, a control module, an LLC module and a voltage and current feedback module. The front end of the system is protected through the piezoresistor MOV1, and the temperature or current change is adjusted and monitored through the variable resistor VR2 and the thermistor RT1, so that the overcurrent or transient high voltage condition of the input end is prevented; the power supply module provides stable working voltage for each control and monitoring module, and ensures that the control system can work normally under any condition without depending on the output state of a main power supply. The PFC module is tightly behind the overcharge current suppression module, an LC filter is formed through an inductor L2 and a capacitor C7, the waveform of the input current is adjusted to be synchronous with the input voltage, and the control module core controller U4 is responsible for adjusting the working parameters of the PFC module and the LLC module to ensure the stability and high efficiency of the whole system.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, specifically to an LLC resonant power supply with integrated overcurrent protection. Background Technology

[0002] LLC resonant converters have become a hot topic in power electronics due to their ability to meet the demanding performance requirements of modern power supply designs. LLC belongs to a large family of resonant converter topologies, and the resonant cavity is a fundamental feature of this family. A resonant cavity is a circuit consisting of an inductor and a capacitor that oscillate at a specific frequency (called the resonant frequency).

[0003] This type of switching mode DC / DC power converter allows for higher switching frequencies (fSW) and reduced switching losses, making it more suitable for high-power and high-efficiency applications. LLC resonant converters are ideal for power applications with precision systems (i.e., high-end consumer electronics) or higher operating power requirements (i.e., charging electric vehicles).

[0004] A novel inverter circuit exists in the prior art that controls the switching transistors in a full-bridge inverter circuit to achieve full-bridge and half-bridge switching, thereby enabling wide-range control of the input voltage. This structure can adapt to different frequency modulation ranges within a wide voltage range, but it increases the complexity of the circuit.

[0005] Furthermore, existing technologies, based on LLC resonant converters, modify the frequency range of the excitation inductor branch by connecting a set of auxiliary capacitors in series. This structure allows the inductance in the circuit to change with varying operating conditions, thereby reducing the frequency adjustment range and widening the gain adjustment range. However, this structure also increases circuit complexity and cost.

[0006] To overcome the limitations of single control methods, existing technologies employ a composite control method using PWM and phase-shifting techniques. This method combines the advantages of PWM control and phase-shifting control, enabling LLC resonant converters to be applied in various situations. However, the composite control method also increases the complexity and cost of the control system.

[0007] Power conversion systems involve multiple voltage levels, resulting in significant power losses during energy conversion. Currently, a key challenge in power electronics is further improving energy conversion efficiency and power density. Traditional power converters are mostly hard-switching, exhibiting substantial switching losses that limit their switching frequency and power density. Utility Model Content

[0008] Purpose of the utility model: This utility model addresses the above-mentioned shortcomings by providing an LLC resonant power supply with integrated overcurrent protection, which can achieve zero-voltage turn-on of the primary-side power transistor and zero-current turn-off of the secondary-side power transistor across the entire load range, greatly reducing switching losses caused by high-frequency switching and effectively reducing EMI, thereby effectively solving the above-mentioned problems existing in the prior art.

[0009] Technical solution: An LLC resonant power supply with integrated overcurrent protection, comprising:

[0010] The overcharge current suppression module protects the front end of the system through the varistor MOV1 and uses the variable resistor VR2 and the thermistor RT1 to regulate and monitor temperature or current changes.

[0011] The power supply module is used to provide a stable operating voltage for each control and monitoring module;

[0012] The PFC module, after the overcharge current suppression module, uses an LC filter composed of inductor L2 and capacitor C7 to adjust the input current waveform to synchronize it with the input voltage.

[0013] The control module adjusts the operating parameters of the PFC module and LLC module through controller U4, and diodes D10 and D9 protect controller U4.

[0014] The LLC module performs DC-DC conversion through a resonant circuit composed of transistors Q1 and Q2, obtains DC input from the PFC module, and generates the required stable DC output under the control of the control module.

[0015] The voltage and current feedback module monitors the output voltage and current in real time and feeds the detected information back to the control module through an optocoupler to dynamically adjust the system's operating state.

[0016] In a further embodiment, the overcharge current suppression module includes a fuse F1, a varistor MOV1, a capacitor CX2, a variable resistor VR2, a capacitor LF1, a capacitor CX1, a capacitor CY4, a capacitor CY5, a thermistor RT1, a rectifier B1, resistors R40, R41, R42, and R43. One end of the fuse F1 is connected to terminal block pin 5, and the other end of the fuse F1 is connected to one end of the varistor MOV1, one end of the capacitor CX2, and pin 1 of the capacitor LF1. The other end of the varistor MOV1 is connected to the other end of the capacitor CX2, terminal block pin 1, and the thermistor RT1. The container LF1 pin 3 is connected to one end of the variable resistor VR2. The other end of the variable resistor VR2 is connected to the capacitor LF1 pin 4, one end of the capacitor CX1, one end of the capacitor CY5, and one end of the thermistor RT1. The other end of the capacitor CX1 is connected to the capacitor LF1 pin 2, one end of the capacitor CY4, and one pin of the rectifier B1. The other end of the capacitor CY4 is connected to the terminal block pin 3 and one end of the capacitor CY5. The other end of the thermistor RT1 is connected to one end of the resistor R40 and one pin of the rectifier B1. The other end of the resistor R40 is connected in series with the resistors R41, R42, and R43 in sequence.

[0017] In a further embodiment, the power supply module includes a power supply unit U9, a diode DP, capacitors E3, E4, C50, C51, C52, C53, C54, C55, C56, a resistor Rd3, and an indicator light LED3. Pin 4 of the power supply unit U9 is connected to the positive terminal of the diode DP, the negative terminal of the diode DP is connected to the positive terminal of the capacitor E3, and the negative terminal of the capacitor E3 is connected to pin 3 of the power supply unit U9. The two ends of the capacitor E3 are connected in parallel with capacitors E4, C50, C51, C52, C53, C54, C55, and C56 in sequence. One end of the resistor Rd3 is connected to the positive terminal of the capacitor E3, and the other end of the resistor Rd3 is connected to the positive terminal of the indicator light LED3. The other end of the indicator light LED3 is connected to the negative terminal of the capacitor E3. Pin 2 of the power supply unit U9 is connected to the other end of the thermistor RT1, and pin 2 of the power supply unit U9 is connected to one end of the capacitor CY4.

[0018] In a further embodiment, the PFC module includes capacitor C7, resistors R19, R22, R27, capacitor C13, inductor L2, diode D4, transistor Q6, resistor R11, transistor Q3, resistor R13, capacitor Cvdd, capacitor C15, resistor R24, transistor Q9, transistor Q10, resistor R39, capacitor C14, resistor R30, resistor 20, resistor R14, resistor R9, capacitor C5, capacitor C4, diode D2, and diode D1. One end of capacitor C7 is connected to... One end of inductor L2, the positive terminal of diode D1, and pin 3 of rectifier B1 are connected. The other end of capacitor C7 is connected to one end of resistor R19, one end of resistor R22, one end of resistor R27, and pin 4 of rectifier B1. The other end of resistor R19 is connected to the other end of resistor R22, one end of capacitor C13, pin 3 of transistor Q6, one end of resistor R13, pin 1 of transistor Q3, the negative terminals of capacitor C4 and C5. The other end of capacitor C13 is connected to the other end of resistor R27. Pin 1 of transistor Q6 is connected to... The positive terminal of diode D4 is connected to one end of resistor R24. The negative terminal of diode D4 is connected to pin 2 of transistor Q6 and one end of resistor R11. The other end of resistor R11 is connected to the other end of resistor R13 and pin 2 of transistor Q3. Pin 3 of transistor Q3 is connected to the other end of inductor L2 and the positive terminal of diode D2. The negative terminal of diode D2 is connected to the positive terminals of capacitors C4 and C5, one end of resistor R9, and the negative terminal of diode D1. The other end of resistor R24 ​​is connected to pin 2 of transistor Q9 and the positive terminal of diode D1. Transistor Q10 pin 2 is connected, and transistor Q9 pin 3 is connected to one end of capacitor C15 and one end of capacitor Cvdd; the other end of capacitor C15 is connected to ground GND, one end of resistor R30 and the other end of capacitor Cvdd; transistor Q9 pin 1 is connected to transistor Q10 pin 1 and one end of resistor R39, transistor Q10 pin 3 is connected to ground GND, and the other end of resistor R9 is connected in series with resistors R14, R20 and R30 in sequence, and capacitor C14 is connected in parallel across resistor R30.

[0019] In a further embodiment, the control module includes a controller U4, a diode D10, a resistor R49, a thermistor RT2, capacitors C30, C29, C101, resistors R53, C24, C27, C25, C26, C32, C31, C28, C23, C21, C18, C20, resistors R52, R46, R47, R45, and a diode D9. The positive terminal of diode D10 is connected to one end of capacitor C30 and pin 1 of controller U4. One end of the diode D10 is connected to one end of the resistor R43; the other end of the diode D10 is connected to one end of the capacitor C29 and one end of the resistor R49; the other end of the resistor R49 is connected to one end of the thermistor RT2, and the other end of the thermistor RT2 is connected to the other end of the capacitor C29, the other end of the capacitor C30, and ground GND; pin 16 of the controller U4 is connected to one end of the capacitor C101, and the other end of the capacitor C101 is connected to ground GND and one end of the resistor R53; pin 15 of the controller U4 is connected to one end of the capacitor C24, and the other end of the capacitor C24 is connected to the capacitor C32. One end of the capacitor is connected to one end of resistor R52, one end of capacitor C28, and one end of capacitor C31. The other end of capacitor C32 is connected to the other end of resistor R52 and ground GND. The other end of capacitor C28 is connected to the other end of capacitor C31, one end of resistor R47, and one end of capacitor C23. The other end of capacitor C23 is connected to one end of resistor R46, one end of resistor R45, and pin 14 of controller U4. The other end of resistor R46 is connected to the other end of resistor R47. The other end of resistor R45 is connected to ground GND. The two ends of resistor R45 are connected to capacitor C28 in sequence. 7. Capacitors C25 and C26 are connected in parallel; pin 13 of controller U4 is connected to one end of capacitor C21 and one end of capacitor C18, the other end of capacitor C18 is connected to ground GND and the other end of capacitor C21, pin 11 of controller U4 is connected to one end of capacitor C20, the other end of capacitor C20 is connected to pin 10 of controller U4 and the negative terminal of diode D9, the positive terminal of diode D9 is connected to pin 6 of controller U4, pin 2 of controller U4 is connected to one end of capacitor C14, and pin 5 of controller U4 is connected to the other end of resistor R39.

[0020] In a further embodiment, the LLC module includes diode D3, transistor Q4, resistors R15, R6, and R10, transistor Q2, diode D6, transistor Q8, resistors R21 and R28, transistor Q7, inductor L3, capacitor C16, transformer T1, transistor Q1, transistor Q11, resistor R25, capacitor C8, and amplifier U1. The positive terminal of diode D3 is connected to pin 1 of transistor Q4 and one end of resistor R15, and the other end of resistor R15 is connected to pin 9 of controller U4. The negative terminals of diode D3 are connected to pin 2 of transistor Q4 and one end of resistor R6. The other end of resistor R6 is connected to one end of resistor R10 and pin 1 of transistor Q2. The other end of resistor R10 is connected to pin 3 of transistor Q4, pin 2 of transistor Q2, one end of inductor L3, pin 3 of transistor Q7, and pin 11 of controller U4. Pin 1 of transistor Q7 is connected to one end of resistor R28 and one end of resistor R21. The other end of resistor R21 is connected to pin 2 of transistor Q8 and the negative terminal of diode D6. The positive terminals of diodes D6 are connected to pin 1 of transistor Q8 and one end of resistor R33. The other end of resistor R28 is connected to ground GND, pin 3 of transistor Q8, and one end of capacitor C16. The other end of resistor R33 is connected to pin 6 of controller Y4. The other end of capacitor C16 is connected to pin 2 of transformer T1. The other end of inductor L3 is connected to pin 1 of transformer T1. Pins 3 of transformer T1 are connected to pin 2 of transistor Q1 and pin 6 of amplifier U1. Pins 6 of transformer T1 are connected to the crystal... Transistor Q11 pin 2 is connected to amplifier U1 pin 3. Transistor Q11 pin 1 is connected to one end of resistor R25. The other end of resistor R25 is connected to amplifier U1 pin 1. The other end of transistor Q11 is connected to transistor Q1 pin 3, amplifier U1 pin 4 and pin 5. Transistor Q1 pin 1 is connected to one end of resistor R7. The other end of resistor R7 is connected to amplifier U1 pin 8. Amplifier U1 pin 7 is connected to one end of capacitor C8. The other end of capacitor C8 is connected to signal ground SGND.

[0021] In a further embodiment, the voltage and current feedback module includes resistors R1, R2, R4, capacitor C6, indicator LED1, capacitor CY1, resistors R12, R16, R17, transistor U15, capacitors C9 and C10, diode D5, resistor R18, optocoupler OC1, diode D7, resistors R32 and R26, capacitors C12 and C11, diode D8, resistor R35, operational amplifiers U3A and U3B, resistor R37, capacitor C19, resistor R34, capacitor C17, resistor R36, resistor R38, resistor R23, resistor R31, and an electric current feedback module. Positioner RP1; one end of resistor R1 is connected to one end of resistor R2, one end of resistor R4, the positive terminal of capacitor C6, the VP terminal, one end of resistor R17, the collector terminal of transistor U15, and pins 4 and 5 of transformer T1. The other end of resistor R1 is connected to the other end of resistor R2, signal ground SGND, one end of resistor R12, one end of resistor R16, and pin 4 of amplifier U1. The other end of resistor R12 is connected to the other end of resistor R16, the negative terminal of indicator light LED1, one end of capacitor CY1, the VN terminal, and the negative terminal of capacitor C6. The positive terminal of indicator light LED1 is connected to the other end of resistor R4. The other end of capacitor CY1 is connected to PE.

[0022] In a further embodiment, the other end of resistor R17 is connected to the negative terminal of diode D5 and the base terminal of transistor U15. The positive terminal of diode D5 is connected to signal ground SGND, one end of capacitor C9, and one end of capacitor C10. The other end of capacitor C9 is connected to the other end of capacitor C10, the emitter terminal of transistor U15, and one end of resistor R18. The other end of resistor R18 is connected to pin 1 of optocoupler OC1. Pin 4 of optocoupler OC1 is connected to pin 16 of controller U4. Pin 3 of optocoupler OC1 is connected to the other end of resistor R53. Pin 2 of optocoupler OC1 is connected to the positive terminals of diodes D7 and D8. The negative terminal of diode D7 is connected to one end of resistor R32. The other end of resistor R32 is connected to one end of resistor R26 and pin 7 of operational amplifier U3A. The other end of resistor R26 is connected to one end of capacitor C12. The other end of capacitor C12 is connected to pin 6 of operational amplifier U3A and resistor R53. One end of R23 is connected to one end of resistor R31. Pin 8 of operational amplifier U3A is connected to one end of capacitor C11. The other end of capacitor C11 is connected to signal ground SGND. Pin 5 of operational amplifier U3A is connected to one end of resistor R34. The other end of resistor R34 is connected to one end of capacitor C17, one end of resistor R36, and pin 3 of operational amplifier U3B. Pin 2 of operational amplifier U3B is connected to one end of capacitor C19 and one end of resistor R38. The other end of capacitor C19 is connected to one end of resistor R37. The other end of resistor R37 is connected to pin 1 of operational amplifier U3B and one end of resistor R35. The other end of resistor R35 is connected to the negative terminal of diode D8. The other end of capacitor C17 is connected to signal ground SGND and the other end of resistor R36. The other end of resistor R23 is connected to the positive input terminal. The other end of resistor R31 is connected to pins 1 and 2 of potentiometer RP1. Pin 3 of potentiometer RP1 is connected to signal ground SGND.

[0023] In a further embodiment, the PFC module further includes an optocoupler OC2, resistors R50 and R0, capacitor CY3, and connector P2. Pin 4 of optocoupler OC2 is connected to one end of capacitor C14, pin 3 of optocoupler OC2 is connected to the other end of capacitor C14, pin 1 of optocoupler OC2 is connected to pins 1 and 3 of connector P2, pins 2 and 4 of connector P2 are both connected to ground DGND and one end of resistor R0, the other end of resistor R0 is connected to capacitor CY3 and signal ground SGND, and the other end of capacitor CY3 is connected to ground GND.

[0024] In a further embodiment, the LLC module further includes a resistor Rd2, an indicator LED2, a resistor R200, capacitors C200, C201, C41, C42, C43, C44, C45, C46, ​​C47, and a voltage regulator U20. One end of the resistor Rd2 is connected to one end of the resistor R200, one end of the capacitor C41, and pin 7 of the amplifier U1. The other end of the resistor Rd2 is connected to the positive terminal of the indicator LED2. The negative terminal of indicator LED2 is connected to signal ground SGND and the other end of capacitor C41. The two ends of capacitor C1 are connected in parallel with capacitors C42, C43, C44, C45, C46, ​​and C47 in sequence. The other end of resistor R200 is connected to one end of capacitor C200 and one end of capacitor C201, as well as pins 1 and 3 of voltage regulator U20. The other end of capacitor C201 is connected to signal ground SGND, capacitor C200, and pin 2 of voltage regulator U20.

[0025] In a further embodiment, the power supply U9 is model HLK-PM01-15V-3W; the thermistors RT1 and RT2 are model NTC-5D-15; the rectifier B1 is model GBU1010; the transistors Q6, Q4, Q8, and Q10 are PNP; the transistor Q9 is model NPN; the controller U4 is model TEA2017; the amplifier U1 is model TEA2096; and the voltage regulator U20 is model TL431.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] By combining the LLC module with the PFC module (power factor correction), power factor correction and voltage regulation of the grid input voltage and current are achieved, thereby improving power conversion efficiency and ensuring the stability of the output voltage.

[0028] The voltage and current feedback module enables precise control of the output voltage and current, ensuring stable operation of the system under various load conditions.

[0029] Through specific voltage and current feedback control, precise control of output voltage and current is achieved, improving system stability; the LLC module can achieve zero-voltage turn-on of the primary-side transistor and zero-current turn-off of the secondary-side transistor across the entire load range, greatly reducing switching losses caused by high-frequency switching and effectively reducing electromagnetic interference.

[0030] The system's front end is protected by a varistor MOV1. A variable resistor VR2 and a thermistor RT1 are used to regulate and monitor temperature and current changes, preventing overcurrent or transient high voltage at the input. The power supply module provides a stable operating voltage to all control and monitoring modules, ensuring the control system can operate normally under any conditions, independent of the main power supply's output state. The PFC module, immediately following the overcharge current suppression module, forms an LC filter using inductor L2 and capacitor C7 to adjust the input current waveform to synchronize with the input voltage. The core controller U4 of the control module adjusts the operating parameters of the PFC and LLC modules, ensuring the stability and efficiency of the entire system. The LLC module performs DC-DC conversion through a resonant circuit composed of transistors Q1 and Q2, obtaining DC input from the PFC module and generating the required stable DC output under the guidance of the control module. The voltage and current feedback module monitors the output voltage and current in real time, feeding the detected information back to the control module via an optocoupler to dynamically adjust the system's operating state, maintaining output accuracy and stability. Attached Figure Description

[0031] Figure 1 This is a block diagram illustrating the working principle of an LLC resonant power supply connected to an AC input.

[0032] Figure 2 This is the circuit diagram of the overcharge current suppression module in an LLC resonant power supply.

[0033] Figure 3 This is the circuit diagram of the power supply module in an LLC resonant power supply.

[0034] Figure 4 This is the circuit diagram of the first part of the PFC module in an LLC resonant power supply.

[0035] Figure 5 This is the circuit diagram of the control module in an LLC resonant power supply.

[0036] Figure 6 This is the circuit diagram of the first part of the LLC module in an LLC resonant power supply.

[0037] Figure 7 This is the circuit diagram of the voltage and current feedback module in an LLC resonant power supply.

[0038] Figure 8 This is the circuit diagram of the second part of the PFC module in an LLC resonant power supply.

[0039] Figure 9 This is the circuit diagram of the second part of the LLC module in an LLC resonant power supply.

[0040] Figure 10 This is a schematic diagram illustrating the relationship between the loss and temperature rise of different magnetic core materials in the embodiment. Detailed Implementation

[0041] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0042] Figure 1 This demonstration illustrates the working principle of connecting the LLC resonant power supply disclosed in this embodiment to an AC input. The 220V AC power supply first passes through an EMI circuit and an uncontrolled rectifier circuit to obtain a DC voltage of approximately 310V. After power factor correction and voltage regulation of the mains input voltage and current by a pre-amplifier (APFC), it outputs a voltage of approximately 400V. This voltage serves as the DC bus voltage of the LLC converter. After high-frequency switching by the switching transistors, it is transmitted to the resonant cavity. After being stepped down by a transformer with isolation coupling, it is sent to the secondary-side synchronous rectifier circuit for rectification, outputting a DC current voltage.

[0043] In this embodiment, the input DC voltage range of the LLC circuit is as follows: minimum input voltage V inmin =300V, maximum input voltage V inmax =400V. LLC circuit rated input DC voltage: V innom =350V. Output voltage and current (maximum): 44V, output power: P0=400W, resonant frequency: f r =100kHz, maximum operating frequency: f max =200kHz.

[0044] In this embodiment, some examples of calculating relevant circuit parameters are disclosed:

[0045] (1) Effective value of primary current

[0046]

[0047] (2) MOSFET voltage, maximum current, and RMS current.

[0048]

[0049]

[0050] (3) Secondary rectifier diode voltage, current, and losses

[0051]

[0052]

[0053] (4) Effective value of resonant capacitor current and maximum voltage

[0054]

[0055]

[0056] (5) Effective value of the current in the output capacitor

[0057]

[0058] In this embodiment, the selection of relevant power devices and transformers is disclosed:

[0059] (1) A 700V / 11.5A high-voltage MOSFET device is used on the high-voltage side.

[0060] Wuxi Xinjieneng NCE70T360D was selected.

[0061] The low-voltage side devices use 200V / 24A low-voltage MOSFET devices.

[0062] Wuxi Xinjieneng NCE0224K was selected.

[0063] (2) Selection of passive components

[0064] When selecting the output capacitor, two factors should be considered: the rated voltage and the ESR (equivalent series resistance).

[0065] (a) Output capacitors are generally used at 80%-85% of their rated voltage. If the output voltage is 44V, then the capacitor's voltage rating is 44 / 0.8=55V, so a 63V capacitor is sufficient.

[0066] (b) ESR can be achieved through the peak voltage (I) of the winding. pk ) and ripple voltage (V pk The peak voltage of the winding (I) is obtained. pk It can also be obtained through the output current.

[0067]

[0068]

[0069] Ultimately, a 560uF / 63V polypropylene film resonant capacitor was selected.

[0070] (3) Transformer selection

[0071] (a) Actual transformer turns ratio

[0072]

[0073] (b) PQ-type magnetic cores are mainly used in switching power supplies. They can achieve the maximum inductance and the largest package area with the smallest core size, thereby achieving the maximum power output. Ultimately, PQ4040 was chosen as the transformer frame.

[0074] (c) Transformer core material

[0075] like Figure 10 The graph shows the relationship between the loss and temperature rise of different core materials under a magnetic field strength of 0.2T and a switching frequency of 100kHz. It can be seen from the graph that PC95 has the lowest loss and temperature rise under all temperature conditions, while PC40 has the highest. Meanwhile, PC95 is also the most expensive of all core materials, indicating a trade-off between core cost and core loss. PC44 has a moderate cost and low core loss, therefore it was chosen as the core material for the main transformer.

[0076] The schematic diagram of an LLC resonant power supply with integrated overcurrent protection disclosed in this embodiment is shown below. Figures 2 to 9 The LLC resonant power supply is powered by an overcharge current suppression module ( Figure 2 As shown), power supply module ( Figure 3 As shown), PFC module ( Figure 4 , Figure 8 As shown), control module ( Figure 5 As shown), LLC module ( Figure 6 , Figure 9 As shown), voltage and current feedback module ( Figure 7 It consists of six parts (as shown).

[0077] Overcharge current suppression module ( Figure 2 (As shown) includes fuse F1, varistor MOV1, capacitor CX2, variable resistor VR2, capacitor LF1, capacitor CX1, capacitor CY4, capacitor CY5, thermistor RT1, rectifier B1, resistor R40, resistor R41, resistor R42 and resistor R43.

[0078] One end of fuse F1 is connected to pin 5 of terminal block. The other end of fuse F1 is connected to one end of varistor MOV1, one end of capacitor CX2, and pin 1 of capacitor LF1. The other end of varistor MOV1 is connected to the other end of capacitor CX2, pin 1 of terminal block, pin 3 of capacitor LF1, and one end of variable resistor VR2. The other end of variable resistor VR2 is connected to pin 4 of capacitor LF1, one end of capacitor CX1, one end of capacitor CY5, and one end of thermistor RT1. The other end of capacitor CX1 is connected to pin 2 of capacitor LF1, one end of capacitor CY4, and pin 1 of rectifier B1. The other end of capacitor CY4 is connected to pin 3 of terminal block and one end of capacitor CY5. The other end of thermistor RT1 is connected to one end of resistor R40 and pin 2 of rectifier B1. The other end of resistor R40 is connected in series with resistors R41, R42, and R43. The front end of the system is protected by varistor MOV1, and temperature or current changes are adjusted and monitored by variable resistor VR2 and thermistor RT1.

[0079] Power supply module ( Figure 3 (As shown) includes power supply U9, diode DP, capacitor E3, capacitor E4, capacitor C50, capacitor C51, capacitor C52, capacitor C53, capacitor C54, capacitor C55, capacitor C56, resistor Rd3, and indicator LED3.

[0080] Pin 4 of power supply U9 is connected to the positive terminal of diode DP. The negative terminal of diode DP is connected to the positive terminal of capacitor E3. The negative terminal of capacitor E3 is connected to pin 3 of power supply U9. The two ends of capacitor E3 are connected in parallel with capacitors E4, C50, C51, C52, C53, C54, C55, and C56 in sequence. One end of resistor Rd3 is connected to the positive terminal of capacitor E3. The other end of resistor Rd3 is connected to the positive terminal of indicator LED3. The other end of indicator LED3 is connected to the negative terminal of capacitor E3. Pin 2 of power supply U9 is connected to the other end of thermistor RT1. Pin 2 of power supply U9 is connected to one end of capacitor CY4. These connections provide a stable operating voltage for various control and monitoring modules.

[0081] PFC module ( Figure 4 , Figure 8 (As shown) includes capacitor C7, resistors R19, R22, R27, capacitor C13, inductor L2, diode D4, transistor Q6, resistor R11, transistor Q3, resistor R13, capacitor Cvdd, capacitor C15, resistor R24, transistor Q9, transistor Q10, resistor R39, capacitor C14, resistor R30, resistor 20, resistor R14, resistor R9, capacitor C5, capacitor C4, diode D2, and diode D1.

[0082] One end of capacitor C7 is connected to one end of inductor L2, the positive terminal of diode D1, and pin 3 of rectifier B1. The other end of capacitor C7 is connected to one end of resistor R19, one end of resistor R22, one end of resistor R27, and pin 4 of rectifier B1. The other end of resistor R19 is connected to the other end of resistor R22, one end of capacitor C13, pin 3 of transistor Q6, one end of resistor R13, pin 1 of transistor Q3, the negative terminals of capacitors C4 and C5. The other end of capacitor C13 is connected to the other end of resistor R27. Pin 1 of transistor Q6 is connected to the positive terminal of diode D4 and one end of resistor R24. The negative terminal of diode D4 is connected to pin 2 of transistor Q6 and one end of resistor R11. The other end of resistor R11 is connected to the other end of resistor R13 and pin 2 of transistor Q3. Pin 3 of Q3 is connected to the other end of inductor L2 and the positive terminal of diode D2. The negative terminal of diode D2 is connected to the positive terminals of capacitors C4 and C5, one end of resistor R9, and the negative terminal of diode D1. The other end of resistor R24 ​​is connected to pin 2 of transistor Q9 and pin 2 of transistor Q10. Pin 3 of transistor Q9 is connected to one end of capacitor C15 and one end of capacitor Cvdd. The other end of capacitor C15 is connected to ground GND, one end of resistor R30, and the other end of capacitor Cvdd. Pin 1 of transistor Q9 is connected to pin 1 of transistor Q10 and one end of resistor R39. Pin 3 of transistor Q10 is connected to ground GND. The other end of resistor R9 is connected in series with resistors R14, R20, and R30. Capacitor C14 is connected in parallel across resistor R30.

[0083] In addition, the PFC module also includes an optocoupler OC2, resistors R50 and R0, capacitor CY3, and connector P2. Pin 4 of optocoupler OC2 is connected to one end of capacitor C14, pin 3 of optocoupler OC2 is connected to the other end of capacitor C14, pin 1 of optocoupler OC2 is connected to pins 1 and 3 of connector P2, pins 2 and 4 of connector P2 are both connected to ground DGND and one end of resistor R0, the other end of resistor R0 is connected to capacitor CY3 and signal ground SGND, and the other end of capacitor CY3 is connected to ground GND. After the overcharge current suppression module, an LC filter is formed by inductor L2 and capacitor C7 to adjust the input current waveform to synchronize it with the input voltage.

[0084] Control module ( Figure 5 (As shown) includes controller U4, diode D10, resistor R49, thermistor RT2, capacitors C30, C29, C101, resistor R53, capacitors C24, C27, C25, C26, C32, C31, C28, C23, C21, C18, C20, resistors R52, R46, R47, R45, and diode D9.

[0085] The positive terminal of diode D10 is connected to one end of capacitor C30, pin 1 of controller U4, and one end of resistor R43; the other end of diode D10 is connected to one end of capacitor C29 and one end of resistor R49; the other end of resistor R49 is connected to one end of thermistor RT2, the other end of thermistor RT2 is connected to the other end of capacitor C29, the other end of capacitor C30, and ground GND; pin 16 of controller U4 is connected to one end of capacitor C101, and the other end of capacitor C101... All terminals are connected to ground (GND) and one end of resistor R53. Pin 15 of controller U4 is connected to one end of capacitor C24. The other end of capacitor C24 is connected to one end of capacitor C32, one end of resistor R52, one end of capacitor C28, and one end of capacitor C31. The other end of capacitor C32 is connected to the other end of resistor R52 and ground (GND). The other end of capacitor C28 is connected to the other end of capacitor C31, one end of resistor R47, and one end of capacitor C23. The other end of capacitor C23 is... One end of resistor R46, one end of resistor R45, and pin 14 of controller U4 are connected. The other end of resistor R46 is connected to the other end of resistor R47. The other end of resistor R45 is connected to ground GND. The two ends of resistor R45 are connected in parallel with capacitors C27, C25, and C26 in sequence. Pin 13 of controller U4 is connected to one end of capacitor C21 and one end of capacitor C18. The other end of capacitor C18 is connected to ground GND and the other end of capacitor C21. Pin 11 of controller U4 is connected to one end of capacitor C20. The other end of capacitor C20 is connected to pin 10 of controller U4 and the negative terminal of diode D9. The positive terminal of diode D9 is connected to pin 6 of controller U4. Pin 2 of controller U4 is connected to one end of capacitor C14. Pin 5 of controller U4 is connected to the other end of resistor R39. The operating parameters of PFC module and LLC module are adjusted through controller U4. Diodes D10 and D9 protect controller U4.

[0086] LLC module ( Figure 6 , Figure 9 (As shown) includes diode D3, transistor Q4, resistor R15, resistor R6, resistor R10, transistor Q2, diode D6, transistor Q8, resistor R21, resistor R28, transistor Q7, inductor L3, capacitor C16, transformer T1, transistor Q1, transistor Q11, resistor R25, capacitor C8, and amplifier U1.

[0087] The positive terminal of diode D3 is connected to pin 1 of transistor Q4 and one end of resistor R15. The other end of resistor R15 is connected to pin 9 of controller U4. The negative terminal of diode D3 is connected to pin 2 of transistor Q4 and one end of resistor R6. The other end of resistor R6 is connected to one end of resistor R10 and pin 1 of transistor Q2. The other end of resistor R10 is connected to pin 3 of transistor Q4, pin 2 of transistor Q2, one end of inductor L3, pin 3 of transistor Q7, and pin 11 of controller U4. Pin 1 of transistor Q7 is connected to one end of resistor R28 and one end of resistor R21. The other end of resistor R21 is connected to pin 2 of transistor Q8 and the negative terminal of diode D6. The positive terminal of diode D6 is connected to pin 1 of transistor Q8 and one end of resistor R33. The other end of resistor R28 is connected to ground GND, pin 3 of transistor Q8, and capacitor. One end of C16 is connected; the other end of resistor R33 is connected to pin 6 of controller Y4; the other end of capacitor C16 is connected to pin 2 of transformer T1; the other end of inductor L3 is connected to pin 1 of transformer T1; pin 3 of transformer T1 is connected to pin 2 of transistor Q1 and pin 6 of amplifier U1; pin 6 of transformer T1 is connected to pin 2 of transistor Q11 and pin 3 of amplifier U1; pin 1 of transistor Q11 is connected to one end of resistor R25; the other end of resistor R25 is connected to pin 1 of amplifier U1; the other end of transistor Q11 is connected to pin 3 of transistor Q1, pin 4 and pin 5 of amplifier U1; pin 1 of transistor Q1 is connected to one end of resistor R7; the other end of resistor R7 is connected to pin 8 of amplifier U1; pin 7 of amplifier U1 is connected to one end of capacitor C8; the other end of capacitor C8 is connected to signal ground SGND.

[0088] In addition, the LLC module also includes resistor Rd2, indicator LED2, resistor R200, capacitor C200, capacitor C201, capacitor C41, capacitor C42, capacitor C43, capacitor C44, capacitor C45, capacitor C46, ​​capacitor C47 and voltage regulator U20.

[0089] One end of resistor Rd2 is connected to one end of resistor R200, one end of capacitor C41, and pin 7 of amplifier U1. The other end of resistor Rd2 is connected to the positive terminal of indicator LED2. The negative terminal of indicator LED2 is connected to signal ground SGND and the other end of capacitor C41. The two ends of capacitor C1 are connected in parallel with capacitors C42, C43, C44, C45, C46, ​​and C47 in sequence. The other end of resistor R200 is connected to one end of capacitor C200, one end of capacitor C201, and pins 1 and 3 of voltage regulator U20. The other end of capacitor C201 is connected to signal ground SGND, capacitor C200, and pin 2 of voltage regulator U20. DC-DC conversion is performed through the resonant circuit composed of transistors Q1 and Q2 to obtain DC input from the PFC module and generate the required stable DC output under the control of the control module.

[0090] Voltage and current feedback module ( Figure 7 (As shown) includes resistors R1, R2, R4, capacitor C6, indicator LED1, capacitor CY1, resistors R12, R16, R17, transistor U15, capacitors C9 and C10, diode D5, resistor R18, optocoupler OC1, diode D7, resistors R32 and R26, capacitors C12 and C11, diode D8, resistor R35, operational amplifier U3A, operational amplifier U3B, resistor R37, capacitor C19, resistor R34, capacitor C17, resistor R36, resistor R38, resistor R23, resistor R31, and potentiometer RP1.

[0091] One end of resistor R1 is connected to one end of resistor R2, one end of resistor R4, the positive terminal of capacitor C6, the VP terminal, one end of resistor R17, the collector terminal of transistor U15, and pins 4 and 5 of transformer T1. The other end of resistor R1 is connected to the other end of resistor R2, signal ground SGND, one end of resistor R12, one end of resistor R16, and pin 4 of amplifier U1. The other end of resistor R12 is connected to the other end of resistor R16, the negative terminal of indicator light LED1, one end of capacitor CY1, the VN terminal, and the negative terminal of capacitor C6. The positive terminal of indicator light LED1 is connected to the other end of resistor R4. The other end of capacitor CY1 is connected to PE.

[0092] The other end of resistor R17 is connected to the negative terminal of diode D5 and the base terminal of transistor U15. The positive terminal of diode D5 is connected to signal ground SGND, one end of capacitor C9 and one end of capacitor C10. The other end of capacitor C9 is connected to the other end of capacitor C10, the emitter terminal of transistor U15, and one end of resistor R18. The other end of resistor R18 is connected to pin 1 of optocoupler OC1. Pin 4 of optocoupler OC1 is connected to pin 16 of controller U4. Pin 3 of optocoupler OC1 is connected to the other end of resistor R53. Pin 2 of optocoupler OC1 is connected to the positive terminals of diodes D7 and D8. The negative terminal of diode D7 is connected to one end of resistor R32. The other end of resistor R32 is connected to one end of resistor R26 and pin 7 of operational amplifier U3A. The other end of resistor R26 is connected to one end of capacitor C12. The other end of capacitor C12 is connected to pin 6 of operational amplifier U3A, one end of resistor R23, and one end of resistor R31. Pin 8 of operational amplifier U3A is connected to... One end of capacitor C11 is connected, and the other end of capacitor C11 is connected to signal ground SGND. Pin 5 of operational amplifier U3A is connected to one end of resistor R34. The other end of resistor R34 is connected to one end of capacitor C17, one end of resistor R36, and pin 3 of operational amplifier U3B. Pin 2 of operational amplifier U3B is connected to one end of capacitor C19 and one end of resistor R38. The other end of capacitor C19 is connected to one end of resistor R37. The other end of resistor R37 is connected to pin 1 of operational amplifier U3B and one end of resistor R35. The other end of resistor R35 is connected to the negative terminal of diode D8. The other end of capacitor C17 is connected to signal ground SGND and the other end of resistor R36. The other end of resistor R23 is connected to the positive input terminal. The other end of resistor R31 is connected to pins 1 and 2 of potentiometer RP1. Pin 3 of potentiometer RP1 is connected to signal ground SGND. The output voltage and current are monitored in real time, and the detected information is fed back to the control module through the optocoupler to dynamically adjust the working state of the system.

[0093] exist Figure 7 In the schematic diagram of the voltage and current feedback module shown, the voltage and current feedback loop mainly consists of an integrated operational amplifier and its peripheral circuits, as well as an optocoupler. The optocoupler converts electrical signals into optical signals, thereby isolating the control circuit from the power circuit signals. The voltage output of the integrated operational amplifier controls the conduction and cutoff of the optocoupler's LED, thus controlling the optocoupler's output. This allows the control signal to be adjusted according to changes in the output voltage and current.

[0094] The current feedback loop, through sampling resistors R12 and R16, converts the difficult-to-handle current quantity into a voltage quantity and sends it to the inverting input of U3B. Based on the characteristics of the integrated operational amplifier, we can derive the expression for the output voltage of U3B as follows:

[0095]

[0096] Substituting the actual resistance values, we get:

[0097]

[0098] From the above expression, it can be seen that when the input voltage... Less than approximately That is, the circuit output current is less than When the input voltage is less than 0, D8 conducts, the optocoupler's LED conducts, and the optocoupler itself conducts. Greater than approximately That is, the circuit output current is greater than When the output voltage of U3B is greater than 0, D8 is cut off, the optocoupler's LED is cut off, and the optocoupler is cut off.

[0099] The output voltage of the voltage feedback loop is divided by R23, R31 and RP1 and sent to the inverting input terminal of U3A.

[0100] Similarly, based on the characteristics of integrated operational amplifiers, we can also derive the expression for the output voltage of U3A:

[0101]

[0102] when At this time

[0103]

[0104] Based on the above expression, it can be concluded that when the circuit output voltage... When the voltage is greater than 20.38V, the output voltage of U3A is less than 0. At this time, D7 conducts, the optocoupler's LED conducts, and the optocoupler itself conducts. Conversely, when the circuit output voltage is less than 20.38V, the output voltage of U3A is less than 0. When the voltage is less than 20.38V, the output voltage of U3A is greater than 0. At this time, D7 is cut off, the optocoupler LED is cut off, and the optocoupler is cut off.

[0105] when At this time

[0106]

[0107] Similarly, based on the above expression, it can be concluded that when the circuit output voltage... When the voltage is greater than 14V, the output voltage of U3A is less than 0. At this time, D7 conducts, the optocoupler's LED conducts, and the optocoupler itself conducts. Conversely, when the circuit output voltage is less than 14V, the output voltage of U3A is less than 0. When the voltage is less than 14V, the output voltage of U3A is greater than 0. At this time, D7 is cut off, the optocoupler LED is cut off, and the optocoupler is cut off.

[0108] The LLC resonant power supply with integrated overcurrent protection disclosed in the above embodiments uses an LLC resonant converter, which can achieve zero-voltage turn-on of the primary power transistor and zero-current turn-off of the secondary power transistor across the entire load range, greatly reducing switching losses caused by high-frequency switching and effectively reducing electromagnetic interference (EMI).

[0109] Furthermore, through reasonable circuit design, the LLC power supply achieves a full-load efficiency of 96.7%, significantly improving energy conversion efficiency. Moreover, this invention achieves a high power density power supply design by optimizing circuit layout and component selection, meeting the demands of modern electronic systems for efficient and compact power supplies.

[0110] It should be further noted that although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself, including but not limited to:

[0111] Alternative control strategies: Employing other advanced control strategies, such as direct digital control (DDC) or intelligent control algorithms (e.g., fuzzy control, neural network control), can also achieve precise control of the LLC resonant converter, thereby widening the gain range and improving system stability and efficiency.

[0112] Improvements to converter structure: In terms of converter structure, in addition to the improvements introduced in this embodiment, such as switching between full-bridge and half-bridge structures, multi-level control, and LCLC resonant converters, other novel circuit topologies can be explored, such as multi-cavity structures and hybrid resonant cavity structures, to further optimize converter performance.

[0113] Component Selection and Parameter Optimization: While this embodiment provides a specific selection scheme for components, in practical applications, other types of components can be selected based on specific needs, such as using different models of MOSFET devices or transformer cores. Furthermore, optimizing component parameters can further improve the converter's performance.

[0114] Adjustment of resonant frequency and switching frequency: In addition to the bandwidth tuning method mentioned in this embodiment, other frequency adjustment strategies can be considered for adjusting the resonant frequency and switching frequency, such as fixed frequency control and frequency sliding control. These strategies can also achieve effective control of the LLC resonant converter and achieve the intended purpose of the invention.

[0115] In other words, various changes in form and detail may be made to this utility model without departing from the spirit and scope of the appended claims.

Claims

1. An LLC resonant power supply with integrated overcurrent protection, characterized in that, include: The overcharge current suppression module protects the front end of the system through the varistor MOV1 and uses the variable resistor VR2 and the thermistor RT1 to regulate and monitor temperature or current changes. The power supply module is used to provide a stable operating voltage for each control and monitoring module; The PFC module, after the overcharge current suppression module, uses an LC filter composed of inductor L2 and capacitor C7 to adjust the input current waveform to synchronize it with the input voltage. The control module adjusts the operating parameters of the PFC module and LLC module through controller U4, and diodes D10 and D9 protect controller U4. The LLC module performs DC-DC conversion through a resonant circuit, obtaining DC input from the PFC module and generating the required stable DC output under the control of the control module. The LLC module includes diode D3, transistor Q4, resistors R15, R6, and R10, transistor Q2, diode D6, transistor Q8, resistors R21 and R28, transistor Q7, inductor L3, capacitor C16, transformer T1, transistor Q1, transistor Q11, resistor R25, capacitor C8, and amplifier U1. The positive terminal of diode D3 is connected to transistor Q4. Pin 1 of diode D3 is connected to one end of resistor R15. The other end of resistor R15 is connected to pin 9 of controller U4. The negative terminal of diode D3 is connected to pin 2 of transistor Q4 and one end of resistor R6. The other end of resistor R6 is connected to one end of resistor R10 and pin 1 of transistor Q2. The other end of resistor R10 is connected to pin 3 of transistor Q4, pin 2 of transistor Q2, one end of inductor L3, pin 3 of transistor Q7, and pin 11 of controller U4. Pin 1 of transistor Q7 is connected to one end of resistor R28 and one end of resistor R21. The other end is connected to pin 2 of transistor Q8 and the negative terminal of diode D6. The positive terminal of diode D6 is connected to pin 1 of transistor Q8 and one end of resistor R33. The other end of resistor R28 is connected to ground GND, pin 3 of transistor Q8, and one end of capacitor C16. The other end of resistor R33 is connected to pin 6 of controller Y4. The other end of capacitor C16 is connected to pin 2 of transformer T1. The other end of inductor L3 is connected to pin 1 of transformer T1. Pin 3 of transformer T1 is connected to pin 2 of transistor Q1 and pin 6 of amplifier U1. Transformer T1 pin 6 is connected to transistor Q11 pin 2 and amplifier U1 pin 3. Transformer Q11 pin 1 is connected to one end of resistor R25, and the other end of resistor R25 is connected to amplifier U1 pin 1. The other end of transistor Q11 is connected to transistor Q1 pin 3, amplifier U1 pin 4 and pin 5. Transformer Q1 pin 1 is connected to one end of resistor R7, and the other end of resistor R7 is connected to amplifier U1 pin 8. Amplifier U1 pin 7 is connected to one end of capacitor C8, and the other end of capacitor C8 is connected to signal ground SGND. The voltage and current feedback module monitors the output voltage and current in real time and feeds the detected information back to the control module through an optocoupler to dynamically adjust the system's operating state.

2. The LLC resonant power supply with integrated overcurrent protection according to claim 1, characterized in that, The overcharge current suppression module includes a fuse F1, a varistor MOV1, a capacitor CX2, a variable resistor VR2, a capacitor LF1, a capacitor CX1, a capacitor CY4, a capacitor CY5, a thermistor RT1, a rectifier B1, resistors R40, R41, R42, and R43. One end of the fuse F1 is connected to pin 5 of the terminal block. The other end of the fuse F1 is connected to one end of the varistor MOV1, one end of the capacitor CX2, and pin 1 of the capacitor LF1. The other end of the varistor MOV1 is connected to the other end of the capacitor CX2, pin 1 of the terminal block, and the capacitor LF1. Pin 3 is connected to one end of the variable resistor VR2. The other end of the variable resistor VR2 is connected to pin 4 of capacitor LF1, one end of capacitor CX1, one end of capacitor CY5, and one end of the thermistor RT1. The other end of capacitor CX1 is connected to pin 2 of capacitor LF1, one end of capacitor CY4, and pin 1 of rectifier B1. The other end of capacitor CY4 is connected to pin 3 of terminal block and one end of capacitor CY5. The other end of the thermistor RT1 is connected to one end of resistor R40 and pin 2 of rectifier B1. The other end of resistor R40 is connected in series with resistors R41, R42, and R43 in sequence.

3. The LLC resonant power supply with integrated overcurrent protection according to claim 1, characterized in that, The power supply module includes a power supply unit U9, a diode DP, capacitors E3, E4, C50, C51, C52, C53, C54, C55, C56, a resistor Rd3, and an indicator light LED3. Pin 4 of the power supply unit U9 is connected to the positive terminal of diode DP, the negative terminal of diode DP is connected to the positive terminal of capacitor E3, and the negative terminal of capacitor E3 is connected to pin 3 of the power supply unit U9. The two ends of capacitor E3 are connected in parallel with capacitors E4, C50, C51, C52, C53, C54, C55, and C56 in sequence. One end of resistor Rd3 is connected to the positive terminal of capacitor E3, and the other end of resistor Rd3 is connected to the positive terminal of indicator light LED3. The other end of indicator light LED3 is connected to the negative terminal of capacitor E3. Pin 2 of the power supply unit U9 is connected to the other end of the thermistor RT1, and pin 2 of the power supply unit U9 is connected to one end of capacitor CY4.

4. The LLC resonant power supply with integrated overcurrent protection according to claim 1, characterized in that, The PFC module includes capacitor C7, resistors R19, R22, R27, capacitor C13, inductor L2, diode D4, transistor Q6, resistor R11, transistor Q3, resistor R13, capacitor Cvdd, capacitor C15, resistor R24, transistor Q9, transistor Q10, resistor R39, capacitor C14, resistor R30, resistor 20, resistor R14, resistor R9, capacitor C5, capacitor C4, diode D2, and diode D1. One end of capacitor C7 is connected to one end of inductor L2. The positive terminal of diode D1 is connected to pin 3 of rectifier B1. The other end of capacitor C7 is connected to one end of resistor R19, one end of resistor R22, one end of resistor R27, and pin 4 of rectifier B1. The other end of resistor R19 is connected to the other end of resistor R22, one end of capacitor C13, pin 3 of transistor Q6, one end of resistor R13, pin 1 of transistor Q3, the negative terminals of capacitors C4 and C5. The other end of capacitor C13 is connected to the other end of resistor R27. Pin 1 of transistor Q6 is connected to the positive terminal of diode D4. The negative terminals of diode D4 and resistor R24 ​​are connected together. The negative terminals of diode D4 are connected to pin 2 of transistor Q6 and one end of resistor R11. The other end of resistor R11 is connected to the other end of resistor R13 and pin 2 of transistor Q3. Pin 3 of transistor Q3 is connected to the other end of inductor L2 and the positive terminal of diode D2. The negative terminals of diode D2 are connected to the positive terminals of capacitors C4 and C5, one end of resistor R9, and the negative terminal of diode D1. The other end of resistor R24 ​​is connected to pin 2 of transistor Q9 and transistor Q1. Pin 2 of transistor Q9 is connected to one end of capacitor C15 and one end of capacitor Cvdd. The other end of capacitor C15 is connected to ground GND, one end of resistor R30, and the other end of capacitor Cvdd. Pin 1 of transistor Q9 is connected to pin 1 of transistor Q10 and one end of resistor R39. Pin 3 of transistor Q10 is connected to ground GND. The other end of resistor R9 is connected in series with resistors R14, R20, and R30. Capacitor C14 is connected in parallel across resistor R30.

5. The LLC resonant power supply with integrated overcurrent protection according to claim 1, characterized in that, The control module includes a controller U4, a diode D10, a resistor R49, a thermistor RT2, capacitors C30, C29, and C101, resistors R53, C24, C27, C25, C26, C32, C31, C28, C23, C21, C18, C20, resistors R52, R46, R47, and R45, and a diode D9. The positive terminal of the diode D10 is connected to one end of capacitor C30, pin 1 of the controller U4, and one end of resistor R43. Connections: The other end of diode D10 is connected to one end of capacitor C29 and one end of resistor R49; the other end of resistor R49 is connected to one end of thermistor RT2, the other end of thermistor RT2 is connected to the other end of capacitor C29, the other end of capacitor C30, and ground GND; pin 16 of controller U4 is connected to one end of capacitor C101, the other end of capacitor C101 is connected to ground GND and one end of resistor R53; pin 15 of controller U4 is connected to one end of capacitor C24, the other end of capacitor C24 is connected to one end of capacitor C32 and resistor R53... One end of resistor R52, one end of capacitor C28, and one end of capacitor C31 are connected. The other end of capacitor C32 is connected to the other end of resistor R52 and ground GND. The other end of capacitor C28 is connected to the other end of capacitor C31, one end of resistor R47, and one end of capacitor C23. The other end of capacitor C23 is connected to one end of resistor R46, one end of resistor R45, and pin 14 of controller U4. The other end of resistor R46 is connected to the other end of resistor R47. The other end of resistor R45 is connected to ground GND. The two ends of resistor R45 are connected to capacitor C27, capacitor C28, and capacitor C31 in sequence. Capacitors C25 and C26 are connected in parallel; pin 13 of controller U4 is connected to one end of capacitor C21 and one end of capacitor C18, the other end of capacitor C18 is connected to ground GND and the other end of capacitor C21, pin 11 of controller U4 is connected to one end of capacitor C20, the other end of capacitor C20 is connected to pin 10 of controller U4 and the negative terminal of diode D9, the positive terminal of diode D9 is connected to pin 6 of controller U4, pin 2 of controller U4 is connected to one end of capacitor C14, and pin 5 of controller U4 is connected to the other end of resistor R39.

6. The LLC resonant power supply with integrated overcurrent protection according to claim 1, characterized in that, The voltage and current feedback module includes resistors R1, R2, and R4, capacitor C6, indicator LED1, capacitor CY1, resistors R12, R16, and R17, transistor U15, capacitors C9 and C10, diode D5, resistor R18, optocoupler OC1, diode D7, resistors R32 and R26, capacitors C12 and C11, diode D8, resistor R35, operational amplifiers U3A and U3B, resistor R37, capacitor C19, resistor R34, capacitor C17, resistor R36, resistor R38, resistor R23, resistor R31, and potentiometer RP1. One end of resistor R1 is connected to one end of resistor R2, one end of resistor R4, the positive terminal of capacitor C6, the VP terminal, one end of resistor R17, the collector terminal of transistor U15, and pins 4 and 5 of transformer T1. The other end of resistor R1 is connected to the other end of resistor R2, signal ground SGND, one end of resistor R12, one end of resistor R16, and pin 4 of amplifier U1. The other end of resistor R12 is connected to the other end of resistor R16, the negative terminal of indicator light LED1, one end of capacitor CY1, the VN terminal, and the negative terminal of capacitor C6. The positive terminal of indicator light LED1 is connected to the other end of resistor R4. The other end of capacitor CY1 is connected to PE.

7. The LLC resonant power supply with integrated overcurrent protection according to claim 6, characterized in that, The other end of resistor R17 is connected to the negative terminal of diode D5 and the base terminal of transistor U15. The positive terminal of diode D5 is connected to signal ground SGND, one end of capacitor C9, and one end of capacitor C10. The other end of capacitor C9 is connected to the other end of capacitor C10, the emitter terminal of transistor U15, and one end of resistor R18. The other end of resistor R18 is connected to pin 1 of optocoupler OC1. Pin 4 of optocoupler OC1 is connected to pin 16 of controller U4. Pin 3 of optocoupler OC1 is connected to the other end of resistor R53. Pin 2 of optocoupler OC1 is connected to the positive terminals of diodes D7 and D8. The negative terminal of diode D7 is connected to one end of resistor R32. The other end of resistor R32 is connected to one end of resistor R26 and pin 7 of operational amplifier U3A. The other end of resistor R26 is connected to one end of capacitor C12. The other end of capacitor C12 is connected to pin 6 of operational amplifier U3A and one end of resistor R23. One end of resistor R31 is connected to the operational amplifier U3A pin 8, which is connected to one end of capacitor C11. The other end of capacitor C11 is connected to signal ground SGND. One end of operational amplifier U3A pin 5 is connected to one end of resistor R34. The other end of resistor R34 is connected to one end of capacitor C17, one end of resistor R36, and one end of operational amplifier U3B pin 3. One end of operational amplifier U3B pin 2 is connected to one end of capacitor C19 and one end of resistor R38. The other end of capacitor C19 is connected to one end of resistor R37. The other end of resistor R37 is connected to one end of operational amplifier U3B pin 1 and one end of resistor R35. The other end of resistor R35 is connected to the negative terminal of diode D8. The other end of capacitor C17 is connected to signal ground SGND and the other end of resistor R36. The other end of resistor R23 is connected to the positive input terminal. The other end of resistor R31 is connected to potentiometer RP1 pins 1 and 2. The potentiometer RP1 pin 3 is connected to signal ground SGND.

8. The LLC resonant power supply with integrated overcurrent protection according to claim 4, characterized in that, The PFC module also includes an optocoupler OC2, a resistor R50, a resistor R0, a capacitor CY3, and a connector P2. Pin 4 of the optocoupler OC2 is connected to one end of the capacitor C14, pin 3 of the optocoupler OC2 is connected to the other end of the capacitor C14, pin 1 of the optocoupler OC2 is connected to pins 1 and 3 of the connector P2, pins 2 and 4 of the connector P2 are both connected to ground DGND and one end of the resistor R0, the other end of the resistor R0 is connected to the capacitor CY3 and the signal ground SGND, and the other end of the capacitor CY3 is connected to ground GND.

9. An LLC resonant power supply with integrated overcurrent protection according to claim 1, characterized in that, The LLC module also includes resistor Rd2, indicator LED2, resistor R200, capacitors C200, C201, C41, C42, C43, C44, C45, C46, ​​C47, and voltage regulator U20. One end of resistor Rd2 is connected to one end of resistor R200, one end of capacitor C41, and pin 7 of amplifier U1. The other end of resistor Rd2 is connected to the positive terminal of indicator LED2. The negative terminal of LED2 is connected to signal ground SGND and the other end of capacitor C41. The two ends of capacitor C1 are connected in parallel with capacitors C42, C43, C44, C45, C46, ​​and C47 in sequence. The other end of resistor R200 is connected to one end of capacitor C200 and one end of capacitor C201, as well as pins 1 and 3 of voltage regulator U20. The other end of capacitor C201 is connected to signal ground SGND, capacitor C200, and pin 2 of voltage regulator U20.

Images