Energy-saving power adapter

Abstract

The present invention discloses an energy-saving power adapter, which belongs to the technical field of electrical appliances, and includes: a first-level architecture and a second-level architecture; the first-level architecture includes: an input filter unit, a power factor correction unit, i.e., a PFC unit, a first voltage and current detection unit, and a first controller unit; the second-level architecture includes: a chopper circuit unit, a transformer unit, an output filter unit, a second voltage and current detection unit, and a second controller unit. The present invention proposes a two-stage power adapter architecture, which has a very high power factor and a total harmonic distortion of the input current of less than 5%; and the PFC output DC voltage of the front stage has a small fluctuation, which is convenient for the optimization design of the DC / DC converter of the rear stage, and is conducive to the energy-saving design of a high-power power adapter. Therefore, the present invention solves the technical problem of how to improve the energy-saving effect of the power adapter.

Description

Technical Field

[0001] The invention relates to the technical field of electrical appliances, and in particular to an energy-saving power adapter. Background Art

[0002] With the advancement and continuous development of science and technology, environmentally friendly and efficient electricity has become one of the most important energy sources in the world. Various electrical equipment used in daily life and work in human society are inseparable from the power system's processing of AC mains.

[0003] At present, AC / DC power supply has made a huge leap from linear power supply to switching power supply, and is still developing. The research on power supply topology and power devices has never stopped. Semiconductor manufacturers continue to launch chips and power devices with better performance, and scholars and engineers have made great contributions to the improvement of power supply performance through research and optimization of power supply topology and circuits. Internal power converters are often used in products such as TVs, desktop computers, and LCD monitors. In addition, external power adapters are also widely used in mobile phones, laptops, printers, game consoles and other fields, which shows the huge application market of power adapters.

[0004] Based on this, Chinese patent CN116131418A discloses a power adapter, which includes: a voltage conversion module, a built-in control module and a power supply module; the voltage conversion module includes an AC / DC conversion unit, which is used to connect to the mains input and convert the mains into a variety of DC power with different voltages and output it to the power supply module; the built-in control module includes: a wireless communication unit, which is used to connect to a designated terminal or cloud; and a control unit, which is connected to the wireless communication unit, the voltage conversion module and the power supply module; the control unit is configured to: receive charging demand information through the wireless communication unit; wherein the charging demand information includes the model of the device to be charged; according to the charging demand information, a preset data mapping relationship set is searched to obtain a matching voltage control instruction and output it. The power adapter disclosed in this patent has the effect of meeting the charging needs of more types of electronic devices.

[0005] However, the power adapter disclosed above still has technical problems of high heat generation and poor energy consumption. Specifically, at present, portable, miniaturized, and lightweight mobile terminals are the mainstream power-consuming devices; for example, mobile terminals such as smart phones and laptops have been widely used. The lightweight and performance improvement of mobile terminals are inseparable from the optimized design of their power supplies, especially the rise of high-power fast-charging power adapters, which has exacerbated the demand for energy-saving power adapters. At present, the development of high-efficiency, low-EMI interference, low-power consumption, and small-volume power adapters is bound to be an important task in the development of portable mobile terminals. Summary of the invention

[0006] Based on this, it is necessary to provide an energy-saving power adapter to address the technical problem of how to improve the energy-saving effect of the power adapter.

[0007] An energy-saving power adapter includes: a first-level structure and a second-level structure, wherein the first-level structure is electrically connected to the second-level structure; the first-level structure includes an input filter unit, a power factor correction unit, a first voltage and current detection unit, and a first controller unit; the second-level structure includes a chopper circuit unit, a transformer unit, an output filter unit, a second voltage and current detection unit, and a second controller unit; The input filter unit is connected to the external AC power input terminal, and the power factor correction unit is connected to the input filter unit; the first voltage and current detection unit is connected to the first controller unit, and the first controller unit is connected to the power factor correction unit; the power factor correction unit is connected to the chopper circuit unit, the transformer unit is respectively connected to the chopper circuit unit and the output filter unit, and the output filter unit is connected to the external DC output terminal; the second voltage and current detection unit is connected to the second controller unit, and the second controller unit is connected to the chopper circuit.

[0008] Furthermore, the circuit of the first-level architecture includes: an EMI filter circuit, a rectifier bridge, an input filter capacitor C1, a switch tube Q1, an inductor L1, a diode D1 and an output filter capacitor C2; the input end of the EMI filter is connected to the current input end of the AC power supply, the output end of the EMI filter is connected to the input end of the rectifier bridge, and the output end of the rectifier bridge is connected to both ends of the input filter capacitor C1; one end of the switch tube Q1 is connected to one end of the input filter capacitor C1, the other end of the switch tube Q1 is connected to one end of the inductor L1, and the other end of the inductor L1 is respectively connected to one end of the input filter capacitor C1 and the output end of the rectifier bridge; the input end of the diode D1 is connected to one end of the inductor L1, the output end of the diode D1 is respectively connected to one end of the load and one end of the output filter capacitor C2, and the other end of the output filter capacitor C2 is respectively connected to one end of the switch tube Q1 and the other end of the load.

[0009] Furthermore, the circuit of the second-level architecture includes: a switch network unit, a resonant tank circuit unit, an ideal transformer unit, a rectifier circuit unit and a low-pass filter unit; the switch network unit is connected to the input voltage, the resonant tank circuit unit, the ideal transformer unit, the rectifier circuit unit and the low-pass filter unit are connected in sequence, and the low-pass filter unit is connected to the load.

[0010] Specifically, the DC input unit is provided by the output of the PFC of the first-stage architecture.

[0011] Specifically, the switch network unit is two MOSFETs that are alternately turned on with a duty cycle of 50%.

[0012] Specifically, the resonant tank circuit unit is composed of a primary excitation inductance Lm, a resonant inductance Lr, and a resonant capacitor Cr; wherein the resonant inductance Lr is played by the primary leakage inductance of the ideal transformer unit.

[0013] Furthermore, the circuit of the second-level architecture includes: a first primary switch tube Q11, a second primary switch tube Q21, a first body diode Doss1, a second body diode Doss2, a first parasitic capacitor Coss1, a second parasitic capacitor Coss2, a resonant inductor Lr, a resonant capacitor Cr, a primary excitation inductor Lm, a transformer T, a first secondary rectifier diode D11, a second secondary rectifier diode D21 and an output filter capacitor Co; one end of the first primary switch tube Q11 is connected to one end of the second primary switch tube Q21 and then connected in parallel to the two ends of the input power supply; the first body diode Doss1 is connected in parallel to the first primary switch tube Q11, and the second body diode Doss2 is connected in parallel to the second primary switch tube Q21; the first parasitic capacitor Coss1 is connected in parallel to the first body diode Doss1. The first secondary rectifier diode D11 and the second secondary rectifier diode D21 are connected in parallel, and the second parasitic capacitor Coss2 is connected in parallel with the second body diode Doss2; one end of the resonant inductor Lr is connected between the first primary switch tube Q11 and the second primary switch tube Q21, one end of the resonant capacitor Cr is connected to one end of the second primary switch tube Q21, and the other end of the resonant inductor Lr and the other end of the resonant capacitor Cr are respectively connected to the two ends of the primary excitation inductor Lm; the input end of the transformer T is connected to the two ends of the primary excitation inductor Lm, and the output end of the transformer T is respectively connected to the input ends of the first secondary rectifier diode D11 and the second secondary rectifier diode D21, and the output ends of the first secondary rectifier diode D11 and the second secondary rectifier diode D21 are respectively connected to one end of the output filter capacitor Co, and the other end of the output filter capacitor Co is connected to the output end of the transformer T.

[0014] In summary, the energy-saving power adapter of the present invention is respectively provided with a first-level architecture and a second-level architecture; the first-level architecture includes: an input filter unit, a power factor correction unit, i.e., a PFC unit, a first voltage and current detection unit, and a first controller unit; the second-level architecture includes: a chopper circuit unit, a transformer unit, an output filter unit, a second voltage and current detection unit, and a second controller unit; the input filter unit is connected to an external AC input terminal, and the power factor correction unit is connected to the input filter unit; the first voltage and current detection unit is connected to the first controller unit, and the first controller unit is connected to the power factor correction unit; the power factor correction unit is connected to the chopper circuit unit, and the transformer unit is respectively connected to the chopper circuit unit and the output filter unit, and the output filter unit is connected to an external DC output terminal; the second voltage and current detection unit is connected to the second controller unit, and the second controller unit is connected to the chopper circuit. The present invention proposes a two-stage power adapter architecture, which first connects the external AC input terminal to the input filter unit, and then passes the current through the input filter to the PFC unit of the previous stage. The front-stage PFC can shape the input current so that the input current is in phase with the input voltage, improve the power factor, and reduce the harmonic component; it can realize PFC in intermittent, critical, and continuous working modes. The rear-stage DC / DC circuit module adopts a half-bridge LLC converter. This implementation scheme has a very high power factor, and the total harmonic distortion of the input current is less than 5%; and the front-stage PFC output DC voltage fluctuation is small, which is convenient for the optimization design of the rear-stage DC / DC converter, and is conducive to the energy-saving design of high-power power adapters. Therefore, the energy-saving power adapter of the present invention solves the technical problem of how to improve the energy-saving effect of the power adapter. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a circuit structure block diagram of the energy-saving power adapter of the present invention; Figure 2 A circuit diagram of the first-level architecture of the energy-saving power adapter of the present invention; Figure 3 It is a circuit structure block diagram of the second-level architecture of the energy-saving power adapter of the present invention; Figure 4 It is a circuit schematic diagram of the second-level architecture of the energy-saving power adapter of the present invention. DETAILED DESCRIPTION

[0016] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0017] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0018] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0019] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0021] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0022] See also Figure 1 The energy-saving power adapter of the present invention includes: a first-level architecture and a second-level architecture; the first-level architecture includes: an input filter unit, a power factor correction unit, i.e., a PFC unit, a first voltage and current detection unit, and a first controller unit; the second-level architecture includes: a chopper circuit unit, a transformer unit, an output filter unit, a second voltage and current detection unit, and a second controller unit; the input filter unit is connected to an external AC input terminal, and the power factor correction unit is connected to the input filter unit; the first voltage and current detection unit is connected to the first controller unit, and the first controller unit is connected to the power factor correction unit; the power factor correction unit is connected to the chopper circuit unit, and the transformer unit is respectively connected to the chopper circuit unit and the output filter unit, and the output filter unit is connected to an external DC output terminal; the second voltage and current detection unit is connected to the second controller unit, and the second controller unit is connected to the chopper circuit.

[0023] Specifically, the energy-saving power adapter of the present invention proposes a two-stage power adapter architecture, which first connects the external AC input terminal to the input filter unit, and then passes the current through the input filter to the power factor correction unit, that is, the PFC unit of the front stage. The front-stage PFC can shape the input current so that the input current is in the same phase as the input voltage, improve the power factor, and reduce the harmonic component. Usually, a Boost converter can be used as the main power circuit of the PFC unit, mainly because of its simple structure, stable operation, mature technology, and PFC can be realized in intermittent, critical, and continuous working modes. The rear-stage DC / DC circuit module can adopt a variety of topologies such as flyback, forward, half-bridge, and full-bridge converters. This implementation scheme has a very high power factor, and the total harmonic distortion of the input current is less than 5%; and the output DC voltage of the front-stage PFC has a small fluctuation, which facilitates the optimization design of the rear-stage DC / DC converter and can be beneficial to the energy-saving design of high-power power adapters.

[0024] For further information, please refer to Figure 2, the input filter unit, the power factor correction unit, the first voltage and current detection unit and the first controller unit can be used as the first-level architecture; and the chopper circuit unit, the transformer unit, the output filter unit, the second voltage and current detection unit and the second controller unit can be used as the second-level architecture.

[0025] Therefore, the core module of the first-level architecture adopts a DCM Boost converter, which works in an inductor current discontinuous mode, and specifically includes: an EMI filter circuit, namely the aforementioned input filter unit, a rectifier bridge, an input filter capacitor C1, a switch tube Q1, an inductor L1, a diode D1 and an output filter capacitor C2; the input end of the EMI filter is connected to the current input end of the AC power supply, the output end of the EMI filter is connected to the input end of the rectifier bridge, and the output end of the rectifier bridge is connected to both ends of the input filter capacitor C1; one end of the switch tube Q1 is connected to one end of the input filter capacitor C1, the other end of the switch tube Q1 is connected to one end of the inductor L1, and the other end of the inductor L1 is respectively connected to one end of the input filter capacitor C1 and the output end of the rectifier bridge; the input end of the diode D1 is connected to one end of the inductor L1, the output end of the diode D1 is respectively connected to one end of the load and one end of the output filter capacitor C2, and the other end of the output filter capacitor C2 is respectively connected to one end of the switch tube Q1 and the other end of the load.

[0026] Specifically, after the AC mains passes through the rectifier bridge, its frequency becomes 100Hz. When the switch tube Q1 is turned on, the current of the inductor L1 rises linearly, and then the current detection signal is compared with the input voltage sampling signal. Since the switching frequency is much greater than 100Hz, it can be considered that the input voltage remains unchanged in each switching cycle; when the current detection signal reaches the input voltage sampling signal, the switch tube Q1 is turned off, and the current at the inductor L1 decreases linearly. In this way, the current of the inductor L1 can track the input voltage in real time, and the average value of the input current of the PFC unit is equal to the average value of the current of the inductor L1; therefore, the average value of the input current changes with the input voltage, realizing the shaping of the input current, making it in phase with the input voltage, that is, realizing the function of PFC.

[0027] Specifically, the PFC working modes can be three, namely: discontinuous mode, i.e. DCM, continuous mode, i.e. CCM and critical continuous mode, i.e. CRM. In the DCM mode, the PFC inductance is small, the current at the inductor L1 is discontinuous, and the diode D1 has no reverse recovery problem. The control circuit is simple, and PWM control is generally used. However, compared with the CCM and CRM modes, under the same output power, the inductor current peak is larger, and there is a larger current stress at the diode D1; therefore, the PFC in the DCM mode is generally used in small and medium power occasions. Furthermore, in the CCM mode, the PFC inductance is large, the inductor current is continuous, and the peak current of the inductor is small, which is suitable for high-power applications. However, there are problems with the CCM mode: the current is not zero when the MOSFET is turned on, which increases the turn-on loss; the current is not zero when the diode is turned off, which will generate a large reverse recovery current, increase the turn-off loss, and the large di / dt during reverse recovery will generate serious electromagnetic interference. The CRM mode is between the DCM mode and the CCM mode. The inductor current is exactly zero at the end of each switching cycle, the switch tube is turned on with zero current, and the diode has no reverse recovery problem. However, it is necessary to detect the output voltage and inductor current. The MOSFET is turned on only when the inductor current is detected to be zero. The PFM control method is used, and the circuit is more complicated than the DCM mode.

[0028] For details, please refer to Figure 3 and Figure 4 In the circuit scheme of the energy-saving power adapter of the present invention, the core of the second-level architecture adopts LLC resonant converter module to realize DC / DC conversion, so as to realize ZVS turn-on of primary MOSFET and ZCS turn-off of secondary diode, which greatly reduces switching loss and has high working efficiency. And the resonant voltage and resonant current of the circuit are both sinusoidal, with less high-frequency harmonic components, which is conducive to reducing EMI interference.

[0029] Specifically, the second-level architecture includes: a switch network unit, a resonant tank circuit unit, an ideal transformer unit, a rectifier circuit unit and a low-pass filter unit; the switch network unit is connected to the input voltage, the resonant tank circuit unit, the ideal transformer unit, the rectifier circuit unit and the low-pass filter unit are connected in sequence, and the low-pass filter unit is connected to the load.

[0030] Specifically, after the input voltage passes through the switch network, it becomes a square wave signal Vn(t) with a frequency of fs and a duty cycle of 50%. By Fourier transforming Vn(t), it can be decomposed into a fundamental component and a high-frequency odd harmonic component; the amplitude of the fundamental component is the largest, and the amplitude of the high-frequency component gradually decreases as the frequency increases. More specifically, the DC input unit can be provided by the PFC output of the previous stage; the switch network unit is two MOSFETs that are alternately turned on with a duty cycle of 50%; the resonant tank circuit unit: consists of the primary excitation inductance Lm, the resonant inductance Lr, and the resonant capacitor Cr. Among them, the resonant inductor Lr can be played by a reasonably designed primary leakage inductance of the transformer; the ideal transformer unit: that is, the design model of the transformer, which can play the role of isolation, energy transfer, and impedance transformation; the rectifier circuit unit: rectifies the AC power signal of the secondary winding; the low-pass filter unit: the output capacitor C. Plays the role of filtering and energy supply; the load: a resistor is used here in the attached figure, which is actually a power terminal such as a mobile phone or laptop connected to the power adapter.

[0031] Furthermore, the second-stage architecture includes: a first primary switch tube Q11, a second primary switch tube Q21, a first body diode Doss1, a second body diode Doss2, a first parasitic capacitor Coss1, a second parasitic capacitor Coss2, a resonant inductor Lr, a resonant capacitor Cr, a primary excitation inductor Lm, a transformer T, a first secondary rectifier diode D11, a second secondary rectifier diode D21 and an output filter capacitor Co; one end of the first primary switch tube Q11 is connected to one end of the second primary switch tube Q21 and then connected in parallel to the two ends of the input power supply; the first body diode Doss1 is connected in parallel to the first primary switch tube Q11, and the second body diode Doss2 is connected in parallel to the second primary switch tube Q21; the first parasitic capacitor Coss1 is connected in parallel to the first body diode Doss1, and the second parasitic capacitor C oss2 is connected in parallel with the second body diode Doss2; one end of the resonant inductor Lr is connected between the first primary switch tube Q11 and the second primary switch tube Q21, one end of the resonant capacitor Cr is connected to one end of the second primary switch tube Q21, the other end of the resonant inductor Lr and the other end of the resonant capacitor Cr are respectively connected to the two ends of the primary excitation inductor Lm; the input end of the transformer T is connected to the two ends of the primary excitation inductor Lm, the output end of the transformer T is respectively connected to the input ends of the first secondary rectifier diode D11 and the second secondary rectifier diode D21, the output ends of the first secondary rectifier diode D11 and the second secondary rectifier diode D21 are respectively connected to one end of the output filter capacitor Co, and the other end of the output filter capacitor Co is connected to the output end of the transformer T.

[0032] Specifically, in the control circuit of the second-level architecture described above, the control mode of the LLC resonant converter is PFM, the first primary switch tube Q11 and the second primary switch tube Q21 are alternately turned on with a duty cycle of 50%, and the circuit gain is adjusted by changing the switching frequency. In order to prevent the two switches from being turned on at the same time, a dead time can be added to each cycle. The LLC resonant converter has two resonant frequencies, one of which is the resonant frequency fr generated by Lr and Cr; the other is the resonant frequency fm generated by Lr and Lm in series with Cr.

[0033] Therefore, according to different input voltage and load conditions, fm and fr can divide the converter's operating frequency into three intervals, namely fm<fs<fr, fs=fr, fs>fr. In different operating frequency intervals, the converter's working process and voltage and current waveforms are different.

[0034] For example, when fs>fr, in the dead time before t0, the circuit completes the discharge of Coss1 and the charging of Coss2, and the resonant current ir flows through Doss1 for freewheeling. At t0, the drive signal of Q11 arrives, ir no longer flows through Ds1, and begins to flow through Q11 for freewheeling. Before the gate signal of Q11 arrives, the voltage between its drain and source has dropped to zero, achieving the zero voltage turn-on of Q11. In this stage, the excitation current im and the resonant current ir flow through the MOSFET in the opposite direction, and the current flowing into the primary winding is im-ir. D11 is turned on, and the voltage across the primary winding is clamped at nVo. Lm does not participate in the resonance, Lr resonates with Cr, and the circuit resonant frequency is fr. After that, ir gradually decreases and crosses zero at t1; at this time, ir flows forward through Q11, and the current flowing into the primary winding becomes im+ir, D11 remains on, the voltage across the primary winding is clamped at nVo, Lm does not participate in resonance, and the circuit resonant frequency is fr. Then, im gradually decreases and crosses zero at t2; at this time, the current flowing into the primary winding becomes ir-im, D11 remains on, the voltage across the primary winding is clamped at nVo, Lm does not participate in resonance, and the circuit resonant frequency is fr. Then, the drive signal of Q11 disappears, Q11 is turned off, and the dead time is entered. ir starts to charge Coss1 / discharge Coss2, and the falling slope of ir is -(Vc-nVo) / Lr. Then, ir decreases to be equal to im, and the charging and discharging process ends. At this time, the voltage between the drain and source of Q21 is zero, preparing for Doss2 to turn on and continue current. In this stage, D11 remains on, the voltage across the primary winding is clamped at nVo, Lm does not participate in the resonance, and the circuit resonant frequency is fr. Finally, since Coss2 is discharged, the voltage between the drain and source of Q21 drops to zero; at this time, Doss2 is turned on to continue the current, and the current flowing out of the primary winding is im-ir, D2 is turned on, the voltage across the primary winding is clamped at -nVo, Lm does not participate in the resonance, and the circuit resonant frequency is fr.

[0035] When fm<fs<fr and fs=fr, the working principle of the converter can be inferred from the above and will not be repeated here.

[0036] In summary, the energy-saving power adapter of the present invention is respectively provided with a first-level architecture and a second-level architecture; the first-level architecture includes: an input filter unit, a power factor correction unit, i.e., a PFC unit, a first voltage and current detection unit, and a first controller unit; the second-level architecture includes: a chopper circuit unit, a transformer unit, an output filter unit, a second voltage and current detection unit, and a second controller unit; the input filter unit is connected to an external AC input terminal, and the power factor correction unit is connected to the input filter unit; the first voltage and current detection unit is connected to the first controller unit, and the first controller unit is connected to the power factor correction unit; the power factor correction unit is connected to the chopper circuit unit, and the transformer unit is respectively connected to the chopper circuit unit and the output filter unit, and the output filter unit is connected to an external DC output terminal; the second voltage and current detection unit is connected to the second controller unit, and the second controller unit is connected to the chopper circuit. The present invention proposes a two-stage power adapter architecture, which first connects the external AC input terminal to the input filter unit, and then passes the current through the input filter to the PFC unit of the previous stage. The front-stage PFC can shape the input current so that the input current is in phase with the input voltage, improve the power factor, and reduce the harmonic component; it can realize PFC in intermittent, critical, and continuous working modes. The rear-stage DC / DC circuit module adopts a half-bridge LLC converter. This implementation scheme has a very high power factor, and the total harmonic distortion of the input current is less than 5%; and the front-stage PFC output DC voltage fluctuation is small, which is convenient for the optimization design of the rear-stage DC / DC converter, and is conducive to the energy-saving design of high-power power adapters. Therefore, the energy-saving power adapter of the present invention solves the technical problem of how to improve the energy-saving effect of the power adapter.

[0037] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0038] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An energy-saving power adapter, characterized in that: It includes: a first-level architecture and a second-level architecture, the first-level architecture is electrically connected to the second-level architecture; the first-level architecture includes an input filter unit, a power factor correction unit, a first voltage and current detection unit, and a first controller unit; the second-level architecture includes a chopper circuit unit, a transformer unit, an output filter unit, a second voltage and current detection unit, and a second controller unit; The input filter unit is connected to the external AC power input terminal, and the power factor correction unit is connected to the input filter unit; the first voltage and current detection unit is connected to the first controller unit, and the first controller unit is connected to the power factor correction unit; the power factor correction unit is connected to the chopper circuit unit, the transformer unit is respectively connected to the chopper circuit unit and the output filter unit, and the output filter unit is connected to the external DC output terminal; the second voltage and current detection unit is connected to the second controller unit, and the second controller unit is connected to the chopper circuit.

2. The energy-saving power adapter according to claim 1, characterized in that: The circuit of the first-level architecture includes: an EMI filter circuit, a rectifier bridge, an input filter capacitor C1, a switch tube Q1, an inductor L1, a diode D1 and an output filter capacitor C2; the input end of the EMI filter is connected to the current input end of the AC power supply, the output end of the EMI filter is connected to the input end of the rectifier bridge, and the output end of the rectifier bridge is connected to both ends of the input filter capacitor C1; one end of the switch tube Q1 is connected to one end of the input filter capacitor C1, the other end of the switch tube Q1 is connected to one end of the inductor L1, and the other end of the inductor L1 is respectively connected to one end of the input filter capacitor C1 and the output end of the rectifier bridge; the input end of the diode D1 is connected to one end of the inductor L1, the output end of the diode D1 is respectively connected to one end of the load and one end of the output filter capacitor C2, and the other end of the output filter capacitor C2 is respectively connected to one end of the switch tube Q1 and the other end of the load.

3. The energy-saving power adapter according to claim 2, characterized in that: The circuit of the second-level architecture includes: a switch network unit, a resonant tank circuit unit, an ideal transformer unit, a rectifier circuit unit and a low-pass filter unit; the switch network unit is connected to the input voltage, the resonant tank circuit unit, the ideal transformer unit, the rectifier circuit unit and the low-pass filter unit are connected in sequence, and the low-pass filter unit is connected to the load.

4. The energy-saving power adapter according to claim 3, characterized in that: The DC input unit is provided by the output of the PFC of the first stage architecture.

5. The energy-saving power adapter according to claim 4, characterized in that: The switch network unit is composed of two MOSFETs that are alternately turned on with a duty cycle of 50%.

6. The energy-saving power adapter according to claim 5, characterized in that: The resonant tank circuit unit is composed of a primary excitation inductance Lm, a resonant inductance Lr, and a resonant capacitor Cr; wherein the resonant inductance Lr is played by the primary leakage inductance of the ideal transformer unit.

7. The energy-saving power adapter according to claim 6, characterized in that: The circuit of the second-level architecture includes: a first primary switch tube Q11, a second primary switch tube Q21, a first body diode Doss1, a second body diode Doss2, a first parasitic capacitor Coss1, a second parasitic capacitor Coss2, a resonant inductor Lr, a resonant capacitor Cr, a primary excitation inductor Lm, a transformer T, a first secondary rectifier diode D11, a second secondary rectifier diode D21 and an output filter capacitor Co; one end of the first primary switch tube Q11 is connected to one end of the second primary switch tube Q21 and then connected in parallel to the two ends of the input power supply; the first body diode Doss1 is connected in parallel to the first primary switch tube Q11, and the second body diode Doss2 is connected in parallel to the second primary switch tube Q21; the first parasitic capacitor Coss1 is connected in parallel to the first body diode Doss1, The second parasitic capacitor Coss2 is connected in parallel with the second body diode Doss2; one end of the resonant inductor Lr is connected between the first primary switch tube Q11 and the second primary switch tube Q21, one end of the resonant capacitor Cr is connected to one end of the second primary switch tube Q21, and the other end of the resonant inductor Lr and the other end of the resonant capacitor Cr are respectively connected to the two ends of the primary excitation inductor Lm; the input end of the transformer T is connected to the two ends of the primary excitation inductor Lm, and the output end of the transformer T is respectively connected to the input ends of the first secondary rectifier diode D11 and the second secondary rectifier diode D21, and the output ends of the first secondary rectifier diode D11 and the second secondary rectifier diode D21 are respectively connected to one end of the output filter capacitor Co, and the other end of the output filter capacitor Co is connected to the output end of the transformer T.

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