A high-power LC resonant full-bridge DC-DC conversion circuit

Abstract

The utility model relates to DC-DC conversion provides a kind of high-power LC resonant full-bridge DC-DC conversion circuit, including LC resonant full-bridge DC-DC conversion circuit, output synchronous rectification circuit and output filter and discharge circuit, wherein:LC resonant full-bridge DC-DC conversion circuit is electrically connected with front-end three-phase PFC voltage-boosting energy storage circuit, for the 800V high-voltage direct current of three-phase PFC voltage-boosting energy storage circuit output direct current conversion;Output synchronous rectification circuit is electrically connected with LC resonant full-bridge DC-DC conversion circuit through transformer, for the high-frequency pulsating direct current of transformer output synchronous rectification;Output filter and discharge circuit are electrically connected with output synchronous rectification circuit, for the rectified direct current filtering processing and provide discharge function.The utility model has realized from 800V high-voltage direct current to 48V low-voltage direct current efficient conversion, provided safe discharge protection, improved power conversion efficiency.

Description

Technical Field

[0001] This utility model relates to the field of DC-DC conversion technology, and in particular to a high-power LC resonant full-bridge DC-DC conversion circuit. Background Technology

[0002] In modern information society, high-power DC-DC converters are widely used in key areas such as data centers, communication base stations, electric vehicles, and uninterruptible power supplies, becoming core equipment for ensuring power conversion efficiency and stability. DC-DC converters primarily achieve DC voltage step-up / step-down conversion through switching power supply technology, providing a stable power output to the load under normal operating conditions. However, in real-world applications, the environment is often extremely complex. Due to the inherent limitations of traditional DC-DC converters in terms of voltage conversion efficiency and power density, their conversion efficiency drops sharply when faced with high-voltage inputs and high-current outputs. This often leads to a decline in the converter's output voltage quality and conversion performance, preventing the DC-DC converter from fully realizing its potential.

[0003] Chinese Patent CN118100636A discloses a multiphase resonant converter and a DC-DC converter. It achieves basic DC-DC conversion functionality through a bridge circuit, resonant circuit, voltage regulation circuit, and rectifier circuit in two resonant conversion modules. The resonant circuit includes a reverse-coupled inductor forming a fully coupled inductor to distribute current evenly. However, this device lacks an effective LC resonant full-bridge control circuit. The single resonant conversion method cannot handle complex high-power conversion demands and exhibits weak resistance to voltage fluctuations. Because the device primarily focuses on multiphase resonance and uniform current distribution, it lacks a dedicated synchronous rectifier circuit design and output filter discharge protection. This results in an inability to provide high-efficiency rectified output and comprehensive safety protection during high-power conversion, leading to low conversion efficiency and insufficient safety protection. Consequently, it fails to meet the high-power communication power supply requirements for high conversion efficiency and safety. Utility Model Content

[0004] In view of this, this utility model proposes a high-power LC resonant full-bridge DC-DC converter circuit to solve the problem that the existing technology lacks a dedicated synchronous rectification circuit design and output filtering and discharge protection, which leads to the inability to provide high-efficiency rectification output and perfect safety protection during high-power conversion, resulting in low conversion efficiency and insufficient safety protection, and failing to meet the power supply requirements of high-power communication power supplies with high requirements for conversion efficiency and safety.

[0005] The technical solution of this utility model is implemented as follows: a high-power LC resonant full-bridge DC-DC converter circuit, the circuit including an LC resonant full-bridge DC-DC converter circuit, an output synchronous rectification circuit, and an output filtering and discharging circuit, wherein: The LC resonant full-bridge DC-DC converter circuit is electrically connected to the front-end three-phase PFC boost energy storage circuit and is used to convert the 800V high-voltage DC power output by the three-phase PFC boost energy storage circuit into DC power. The output synchronous rectification circuit and the LC resonant full-bridge DC-DC converter circuit are electrically connected through a transformer, and are used to synchronously rectify the high-frequency pulsating DC power output by the transformer. The output filtering and discharge circuit is electrically connected to the output synchronous rectification circuit, and is used to filter the rectified DC power and provide a discharge function.

[0006] Based on the above technical solutions, preferably, the LC resonant full-bridge DC-DC converter circuit includes a full-bridge switching module, which includes an upper left bridge arm, a lower left bridge arm, an upper right bridge arm, and a lower right bridge arm. Each bridge arm is composed of two MOSFETs connected in series. The upper left bridge arm and the lower left bridge arm, as well as the upper right bridge arm and the lower right bridge arm, are alternately turned on and off to form a full-bridge converter circuit. The two MOSFETs are connected in series to share the voltage of the 800V high-voltage DC power.

[0007] Based on the above technical solutions, preferably, the LC resonant full-bridge DC-DC converter circuit includes an LC resonant module, which is composed of a first resonant inductor, a second resonant inductor, multiple resonant capacitors and a varistor; The LC resonant module enables the MOSFET to operate stably in the zero-voltage operating region by forming a high-frequency LC resonance.

[0008] Based on the above technical solutions, preferably, the LC resonant full-bridge DC-DC converter circuit includes a transformer primary module, which includes a first primary winding and a second primary winding of the transformer. The transformer primary module is connected to the full-bridge switching module and is used to receive the high-frequency pulsating DC power output by the full-bridge switching module and transmit electrical energy to the transformer secondary through electromagnetic coupling.

[0009] Based on the above technical solutions, preferably, the full-bridge switching module further includes a spike absorption unit and an anti-reverse unit. The spike absorption unit includes multiple absorption capacitors for absorbing spike noise from the MOSFET. The anti-reverse unit consists of multiple diodes and is used to prevent the operating current of the upper and lower bridge arms from reversing.

[0010] Based on the above technical solutions, preferably, the output synchronous rectification circuit includes a synchronous rectification module, which is composed of twelve MOSFETs. The twelve MOSFETs are used to receive the high-frequency pulsating DC power output from the transformer and convert the high-frequency pulsating DC power into DC power through self-excited synchronous rectification. By replacing ordinary rectifier diodes with MOSFETs, conduction losses can be reduced.

[0011] Based on the above technical solutions, preferably, the output synchronous rectification circuit includes a transformer secondary module, which includes a third secondary winding, a fourth secondary winding, and a fifth secondary winding of the transformer. The transformer secondary module is used to receive the high-frequency pulsating DC power transmitted from the transformer primary module and provide positive and negative high-frequency pulsating DC power inputs to the synchronous rectification module.

[0012] Based on the above technical solutions, preferably, the synchronous rectification module includes a rectification control unit, which is used to receive the voltage signal of the transformer secondary module and output a control signal to control the switching timing of the twelve MOSFETs so that the MOSFETs and the transformer secondary winding voltage signal switch synchronously.

[0013] Based on the above technical solutions, preferably, the output filtering and discharge circuit includes an output filtering module, which includes an output inductor and an output capacitor, and the output inductor and the output capacitor form an LC filtering circuit. The output filter module receives synchronously rectified DC power, and the LC filter circuit filters out high-frequency ripple and EMI noise in the DC power, outputting a smooth and clean 48V low-voltage DC power.

[0014] Based on the above technical solutions, preferably, the output filtering and discharge circuit includes a discharge protection module, which consists of a discharge resistor and a control switch; the discharge protection module receives DC power from the output filtering module, and releases the remaining electrical energy stored in the output capacitor through the discharge resistor when the circuit is powered off, so as to prevent residual electrical energy from causing danger to equipment and personnel.

[0015] The high-power LC resonant full-bridge DC-DC converter circuit provided by this utility model has the following advantages compared with the prior art: By integrating and electrically connecting the LC resonant full-bridge DC-DC converter circuit, the output synchronous rectification circuit, and the output filtering and discharge circuit, a high-efficiency conversion from 800V high-voltage DC to 48V low-voltage DC is achieved. The LC resonant technology enables the MOSFET to operate in the zero-voltage region, reducing switching losses. The synchronous rectification circuit uses MOSFETs instead of ordinary diodes to improve rectification efficiency. The output filtering and discharge circuit effectively suppresses high-frequency noise and EMI interference and provides safe discharge protection, thereby improving power conversion efficiency and output DC power quality. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a system structure diagram of a high-power LC resonant full-bridge DC-DC converter circuit according to the present invention; Figure 2 This is a circuit diagram of a high-power LC resonant full-bridge DC-DC converter circuit according to the present invention. Detailed Implementation

[0018] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0019] Please see Figure 1 This utility model provides a high-power LC resonant full-bridge DC-DC converter circuit, which includes an LC resonant full-bridge DC-DC converter circuit, an output synchronous rectification circuit, and an output filtering and discharging circuit, wherein: The LC resonant full-bridge DC-DC converter circuit is electrically connected to the front-end three-phase PFC boost energy storage circuit and is used to convert the 800V high-voltage DC power output by the three-phase PFC boost energy storage circuit into DC power. The output synchronous rectification circuit and the LC resonant full-bridge DC-DC converter circuit are electrically connected through a transformer, and are used to synchronously rectify the high-frequency pulsating DC power output by the transformer. The output filtering and discharge circuit is electrically connected to the output synchronous rectification circuit, and is used to filter the rectified DC power and provide a discharge function.

[0020] Specifically, this embodiment integrates and electrically connects the LC resonant full-bridge DC-DC converter circuit, the output synchronous rectification circuit, and the output filtering and discharge circuit, achieving efficient conversion from 800V high-voltage DC to 48V low-voltage DC. The LC resonant technology enables the MOSFET to operate in the zero-voltage region, reducing switching losses. The synchronous rectification circuit uses MOSFETs instead of ordinary diodes to improve rectification efficiency. The output filtering and discharge circuit effectively suppresses high-frequency noise and EMI interference and provides safe discharge protection, thereby improving power conversion efficiency and output DC power quality.

[0021] The LC resonant full-bridge DC-DC converter circuit includes a full-bridge switching module, which includes an upper left bridge arm, a lower left bridge arm, an upper right bridge arm, and a lower right bridge arm. Each bridge arm is composed of two MOSFETs connected in series. The upper left bridge arm and the lower left bridge arm, as well as the upper right bridge arm and the lower right bridge arm, are alternately turned on and off to form a full-bridge converter circuit. The two MOSFETs are connected in series to share the voltage of the 800V high-voltage DC power.

[0022] The LC resonant full-bridge DC-DC converter circuit includes an LC resonant module, which consists of a first resonant inductor, a second resonant inductor, multiple resonant capacitors, and a varistor. The LC resonant module enables the MOSFET to operate stably in the zero-voltage operating region by forming a high-frequency LC resonance.

[0023] The LC resonant full-bridge DC-DC converter circuit includes a transformer primary module, which includes a first primary winding and a second primary winding of the transformer. The transformer primary module is connected to the full-bridge switching module and is used to receive the high-frequency pulsating DC power output by the full-bridge switching module and transmit electrical energy to the transformer secondary through electromagnetic coupling.

[0024] The full-bridge switching module also includes a spike absorption unit and an anti-reverse unit. The spike absorption unit includes multiple absorption capacitors for absorbing spike noise from the MOSFET. The anti-reverse unit consists of multiple diodes and is used to prevent the operating current of the upper and lower bridge arms from reversing.

[0025] In a specific embodiment, please refer to Figure 2The LC resonant full-bridge DC-DC converter circuit consists of MOSFETs Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, diodes D1, D2, D3, D4, inductors L1, L2, capacitors C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, varistors RV1, RV2, and the primary windings T1-1 and T1-2 of transformer T1.

[0026] MOSFETs Q1 and Q2 are connected in series to form the upper left arm of the full-bridge circuit, MOSFETs Q5 and Q6 are connected in series to form the lower left arm of the full-bridge circuit, MOSFETs Q3 and Q4 are connected in series to form the upper right arm of the full-bridge circuit, and MOSFETs Q7 and Q8 are connected in series to form the lower right arm of the full-bridge circuit. The two MOSFETs in series in the four arms can share the 800V high voltage DC power, so that the MOSFETs will not be damaged by the DC high voltage.

[0027] The MOSFETs Q1 and Q2 in the upper left bridge arm and Q5 and Q6 in the lower left bridge arm, as well as the MOSFETs Q3 and Q4 in the upper right bridge arm and Q7 and Q8 in the lower right bridge arm, are alternately turned on and off to form a full-bridge converter circuit. Capacitors C1, C2, C3, C4, C5, C6, C7, and C8 have the function of absorbing the spike noise of MOSFETs Q1, Q2, Q3, Q4, Q5, Q6, Q7, and Q8.

[0028] Diodes D1, D2, D3, and D4 prevent reverse current flow in the upper and lower bridge arms. Inductors L1 and L2, capacitors C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, and C20, and varistors RV1 and RV2 form an LC resonant circuit, creating a high-frequency LC resonance. Regardless of changes in the input voltage and output current of the full-bridge DC-DC converter circuit within its operating range, the MOSFETs always operate stably in the zero-voltage operating region, thereby reducing the power consumption of the module's DC-DC converter circuit and improving its efficiency. This LC resonant full-bridge DC-DC converter circuit connection method in this embodiment has the effect of increasing the input voltage and increasing the output current. The overall circuit topology design is simple, and the performance achieves a balance.

[0029] Specifically, this embodiment uses a full-bridge switching module consisting of two MOSFETs connected in series in each bridge arm to effectively distribute the 800V high-voltage DC voltage and prevent device breakdown damage. By combining an LC resonant module composed of an inductor, capacitor, and varistor to form a high-frequency resonance, the MOSFET is always stably operating in the zero-voltage operating region, significantly reducing switching losses and module power consumption. Simultaneously, the configuration of a spike absorption unit and an anti-reverse unit eliminates switching spike noise and prevents current reversal, thereby achieving high-efficiency DC-DC conversion with high-voltage input and high-current output. The overall circuit topology is simple and the performance is balanced, which greatly improves the working efficiency and reliability of high-power DC-DC conversion circuits.

[0030] The output synchronous rectification circuit includes a synchronous rectification module, which consists of twelve MOSFETs. The twelve MOSFETs are used to receive the high-frequency pulsating DC power output from the transformer and convert the high-frequency pulsating DC power into DC power through self-excited synchronous rectification. The conduction loss is reduced by replacing the ordinary rectifier diode with the MOSFET.

[0031] The output synchronous rectification circuit includes a transformer secondary module, which includes a third secondary winding, a fourth secondary winding, and a fifth secondary winding of the transformer. The transformer secondary module is used to receive the high-frequency pulsating DC power transmitted from the transformer primary module and provide positive and negative high-frequency pulsating DC power inputs to the synchronous rectification module.

[0032] The synchronous rectification module includes a rectification control unit, which receives the voltage signal from the transformer secondary module and outputs a control signal to control the switching timing of the twelve MOSFETs so that the MOSFETs switch synchronously with the voltage signal of the transformer secondary winding.

[0033] In a specific embodiment, please refer to Figure 2 The output synchronous rectification circuit consists of MOSFETs Q9, Q10, Q11, Q12, Q13, Q14, Q15, Q16, Q17, Q18, Q19, and Q20, diode D5, resistors R1, R2, R3, and R4, capacitors C35, C36, and C37, and the secondary windings T1-3, T1-4, and T1-5 of transformer T1. The synchronous rectification circuit employs a self-excited synchronous rectification method that follows the transformer's output waveform, resulting in a simpler and more efficient circuit. The circuit composed of resistors R1, R2, R3, R4, capacitors C35, C36, C37, and diode D5 has the function of absorbing the spike noise when the MOSFET is working, improving the smoothness of the output DC waveform, preventing sudden spikes and reducing the power consumption of the MOSFET.

[0034] Specifically, this embodiment uses twelve MOSFETs to replace ordinary rectifier diodes to form a synchronous rectification module, which significantly reduces conduction losses and power consumption; The transformer's three secondary windings provide two high-frequency pulsating DC inputs, one positive and one negative. Combined with the rectifier control unit, it enables precise synchronous switching of the MOSFET and the transformer's secondary winding voltage signal. The self-excited synchronous rectification method, which follows the transformer's output waveform, makes the circuit simpler and more efficient. Meanwhile, the spike absorption circuit effectively eliminates the spike noise during MOSFET operation, improves the smoothness of the output DC waveform, and prevents sudden spikes from damaging the device. This achieves high-efficiency, low-loss AC-to-DC conversion, significantly improving the working efficiency of the rectifier circuit and the quality of the output power.

[0035] The output filtering and discharge circuit includes an output filtering module, which includes an output inductor and an output capacitor, and the output inductor and the output capacitor form an LC filtering circuit. The output filter module receives synchronously rectified DC power, and the LC filter circuit filters out high-frequency ripple and EMI noise in the DC power, outputting a smooth and clean 48V low-voltage DC power.

[0036] The output filtering and discharge circuit includes a discharge protection module, which consists of a discharge resistor and a control switch. The discharge protection module receives DC power from the output filtering module and releases the remaining electrical energy stored in the output capacitor through the discharge resistor when the circuit is powered off, so as to prevent the residual electrical energy from causing danger to the equipment and personnel.

[0037] In a specific embodiment, please refer to Figure 2 The output filtering and discharge circuit consists of resistors R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, capacitors C21, C22, C23, C24, C25, C26, C27, C28, C29, C30, C31, C32, C33, C34, C38, C39, C40, C41, C42, C43, C44, C45, C46, ​​C47, C48, C49, transistors Q21, Q22, fuses FU1, FU2, FU3, FU4, and inductor L3. Capacitors C21, C22, C23, C24, C25, C26, C27, C28, C29, C30, C31, C32, C33, C34, C40, and C41, along with inductor L3, form the output LC filter circuit. This circuit effectively suppresses high-frequency noise generated within the main circuit, resulting in a more standard and clean waveform, and providing a 48V low-voltage DC output that meets the user's load requirements.

[0038] Resistors R7 and R8, and capacitors C38, C39, C42, C43, C44, C45, C46, ​​C47, and C48 form an EMI filter circuit, which effectively suppresses high-frequency EMI noise generated inside the main circuit.

[0039] Resistors R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, capacitor C49, and transistors Q21 and Q22 form a discharge circuit. When the rectifier module is working normally and has output, transistor Q21 is turned on and resistor R12 is connected, providing a dummy load function to balance the output waveform and prevent intermittent shutdown. When the rectifier module is powered off, transistor Q21 is cut off and not working, while Q22 is turned on and working. The remaining energy in the electrolytic capacitor of the output filter circuit is discharged through resistors R13, R14, R15, R16, R17, and R18. Fuses FU1, FU2, FU3, and FU4 act as the front-end circuit for output current overload protection. Resistors R5 and R6 form the output current detection circuit, which converts the analog current signal into a voltage signal for processing by the microcontroller.

[0040] Specifically, this embodiment uses an LC filter circuit composed of an output inductor and a capacitor to effectively filter out high-frequency ripples in the DC power supply. Combined with an EMI filter circuit, it suppresses high-frequency EMI noise generated inside the main circuit, making the output waveform more standard and clean, and outputting a stable 48V low-voltage DC power supply. By configuring a discharge protection module, the output waveform is balanced through the dummy load function during normal operation to prevent intermittent shutdown. When the machine is turned off, the residual energy in the output filter capacitor is automatically discharged safely, effectively preventing residual voltage from posing a danger to equipment and personnel. It integrates current detection circuit and overload protection function, converts current signal into voltage signal for easy processing by microcontroller and protects front-end circuit through fuse, thus realizing high-quality DC output and perfect safety protection.

[0041] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A high-power LC resonant full-bridge DC-DC converter circuit, characterized in that, The circuit includes an LC resonant full-bridge DC-DC converter circuit, an output synchronous rectification circuit, and an output filtering and discharging circuit, wherein: The LC resonant full-bridge DC-DC converter circuit is electrically connected to the front-end three-phase PFC boost energy storage circuit and is used to convert the 800V high-voltage DC power output by the three-phase PFC boost energy storage circuit into DC power. The output synchronous rectification circuit and the LC resonant full-bridge DC-DC converter circuit are electrically connected through a transformer, and are used to synchronously rectify the high-frequency pulsating DC power output by the transformer. The output filtering and discharge circuit is electrically connected to the output synchronous rectification circuit, and is used to filter the rectified DC power and provide a discharge function.

2. The high-power LC resonant full-bridge DC-DC converter circuit as described in claim 1, characterized in that, The LC resonant full-bridge DC-DC converter circuit includes a full-bridge switching module, which includes an upper left bridge arm, a lower left bridge arm, an upper right bridge arm, and a lower right bridge arm. Each bridge arm is composed of two MOSFETs connected in series. The upper left bridge arm and the lower left bridge arm, as well as the upper right bridge arm and the lower right bridge arm, are alternately turned on and off to form a full-bridge converter circuit. The two MOSFETs are connected in series to share the voltage of the 800V high-voltage DC power.

3. The high-power LC resonant full-bridge DC-DC converter circuit as described in claim 2, characterized in that, The LC resonant full-bridge DC-DC converter circuit includes an LC resonant module, which consists of a first resonant inductor, a second resonant inductor, multiple resonant capacitors, and a varistor. The LC resonant module enables the MOSFET to operate stably in the zero-voltage operating region by forming a high-frequency LC resonance.

4. The high-power LC resonant full-bridge DC-DC converter circuit as described in claim 3, characterized in that, The LC resonant full-bridge DC-DC converter circuit includes a transformer primary module, which includes a first primary winding and a second primary winding of the transformer. The transformer primary module is connected to the full-bridge switching module and is used to receive the high-frequency pulsating DC power output by the full-bridge switching module and transmit electrical energy to the transformer secondary through electromagnetic coupling.

5. A high-power LC resonant full-bridge DC-DC converter circuit as described in claim 4, characterized in that, The full-bridge switching module also includes a spike absorption unit and an anti-reverse unit. The spike absorption unit includes multiple absorption capacitors for absorbing spike noise from the MOSFET. The anti-reverse unit consists of multiple diodes and is used to prevent the operating current of the upper and lower bridge arms from reversing.

6. The high-power LC resonant full-bridge DC-DC converter circuit as described in claim 1, characterized in that, The output synchronous rectification circuit includes a synchronous rectification module, which consists of twelve MOSFETs. The twelve MOSFETs are used to receive the high-frequency pulsating DC power output from the transformer and convert the high-frequency pulsating DC power into DC power through self-excited synchronous rectification. By replacing ordinary rectifier diodes with MOSFETs, conduction losses can be reduced.

7. A high-power LC resonant full-bridge DC-DC converter circuit as described in claim 6, characterized in that, The output synchronous rectification circuit includes a transformer secondary module, which includes a third secondary winding, a fourth secondary winding, and a fifth secondary winding of the transformer. The transformer secondary module is used to receive the high-frequency pulsating DC power transmitted from the transformer primary module and provide positive and negative high-frequency pulsating DC power inputs to the synchronous rectification module.

8. A high-power LC resonant full-bridge DC-DC converter circuit as described in claim 7, characterized in that, The synchronous rectification module includes a rectification control unit, which receives the voltage signal from the transformer secondary module and outputs a control signal to control the switching timing of the twelve MOSFETs so that the MOSFETs switch synchronously with the voltage signal of the transformer secondary winding.

9. A high-power LC resonant full-bridge DC-DC converter circuit as described in claim 1, characterized in that, The output filtering and discharge circuit includes an output filtering module, which includes an output inductor and an output capacitor, and the output inductor and the output capacitor form an LC filtering circuit. The output filter module receives synchronously rectified DC power, and the LC filter circuit filters out high-frequency ripple and EMI noise in the DC power, outputting a smooth and clean 48V low-voltage DC power.

10. A high-power LC resonant full-bridge DC-DC converter circuit as described in claim 9, characterized in that, The output filtering and discharge circuit includes a discharge protection module, which consists of a discharge resistor and a control switch. The discharge protection module receives DC power from the output filtering module and releases the remaining electrical energy stored in the output capacitor through the discharge resistor when the circuit is powered off, so as to prevent the residual electrical energy from causing danger to the equipment and personnel.

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