Power supply system

Abstract

A power supply system comprises a main circuit, a sampling circuit, a driving circuit and a controller, wherein: the power conversion circuit in the main circuit comprises an LLC resonant conversion circuit; the sampling circuit is electrically connected with part of the circuit in the main circuit, and is used for sampling information of input signals, resonant capacitor signals and output signals of the main circuit; the controller is electrically connected with the sampling circuit and the driving circuit, and is used for controlling the driving circuit based on the information sampled by the sampling circuit, so that the driving circuit drives the LLC resonant conversion circuit to realize active power factor correction, electrical isolation and voltage conversion; wherein the control strategy of the controller makes the input voltage of the LLC resonant conversion circuit be pulse direct current voltage or stable direct current voltage, and makes the LLC resonant conversion circuit work in a wide frequency range near the resonant frequency and far away from the resonant frequency. The power supply system reduces the number of power devices used, reduces the cost, reduces the volume, works in a soft switching state in all working conditions, and is conducive to high frequency.

Description

Technical Field

[0001] This application relates to the field of charging technology, and more specifically to a power supply system. Background Technology

[0002] Smart fast charging is widely used in consumer power systems such as smartphones and tablets. With the continuous updates to the USB Power Delivery (PD) standard, fast charging power is increasing. Related fast charging products are developing towards higher frequency, smaller size, and higher power density. However, for products with power greater than 75W, relevant regulations have strict requirements on current harmonics. To meet these regulations, traditional solutions typically employ a two-stage power conversion architecture: a power factor correction (PFC) stage and a direct current to direct current converter (DC / DC) isolation stage.

[0003] The increase in PFC power levels not only increases costs and reduces efficiency, but also limits further increases in power density and hinders product miniaturization. Summary of the Invention

[0004] This application is made to address the aforementioned problems. According to one aspect of this application, a power supply system is provided, comprising a main circuit, a sampling circuit, a drive circuit, and a controller, wherein: the power conversion circuit in the main circuit includes an LLC resonant converter circuit; the sampling circuit is electrically connected to a portion of the main circuit and is used to sample the input signal, resonant capacitor signal, and output signal of the main circuit; the controller is electrically connected to the sampling circuit and the drive circuit and is used to control the drive circuit based on the information sampled by the sampling circuit, so that the drive circuit drives the LLC resonant converter circuit to achieve active power factor correction, electrical isolation, and voltage conversion; wherein the control strategy of the controller allows the input voltage of the LLC resonant converter circuit to be a pulsed DC voltage or a stable DC voltage, and allows the LLC resonant converter circuit to operate in a wide frequency range, both near and far from the resonant frequency (greater than or less than the resonant frequency).

[0005] In one embodiment of this application, the information sampled by the sampling circuit includes any one of the following: input voltage information of the main circuit, resonant capacitor voltage or current information, and output voltage information and output current information, wherein: the input voltage information includes at least one of the following: amplitude, peak value, phase, and zero-crossing point of the input voltage of the main circuit; the resonant capacitor voltage or current information includes at least one of the following: amplitude, peak value, phase, and zero-crossing point of the resonant capacitor voltage or current of the main circuit; the output voltage information includes at least one of the following: amplitude, peak value, phase, and zero-crossing point of the output voltage of the main circuit; and the output current information includes at least one of the following: amplitude, peak value, phase, and zero-crossing point of the output current of the main circuit.

[0006] In one embodiment of this application, the LLC resonant converter circuit includes a half-bridge LLC resonant converter circuit or a full-bridge LLC resonant converter circuit.

[0007] In one embodiment of this application, the resonant inductor in the LLC resonant converter circuit includes a discrete resonant inductor or a magnetically integrated resonant inductor, wherein the magnetically integrated resonant inductor refers to the resonant inductor being integrated with the main transformer.

[0008] In one embodiment of this application, the rectifier circuit in the LLC resonant converter circuit includes a bridge rectifier circuit or a full-wave rectifier circuit.

[0009] In one embodiment of this application, the rectifier circuit in the LLC resonant converter circuit includes a diode rectifier circuit or a synchronous rectifier circuit composed of power switching semiconductor devices (such as MOS, GaN, etc.).

[0010] In one embodiment of this application, the main circuit includes an input circuit, a filter circuit, the power conversion circuit, and an output circuit, wherein: the input circuit includes an AC input interface for receiving AC power; the filter circuit is electrically connected to the input circuit and is used to filter and rectify the AC signal to obtain pulsed DC power or stable DC power; the power conversion circuit is electrically connected to the filter circuit and is used to invert the pulsed DC power or stable DC power into high-frequency AC power, and then rectify and filter the high-frequency AC power after isolation and transformation to obtain low-voltage DC power; the output circuit is electrically connected to the power conversion circuit, and the output circuit includes a DC power output interface for output stage processing of the low-voltage DC power to obtain the output of the power supply system.

[0011] In one embodiment of this application, the filtering circuit includes an electromagnetic compatibility (EMC) filtering circuit and a rectifier filtering circuit, wherein: the EMC filtering circuit is electrically connected to the input circuit and is used to perform EMC filtering on the AC power from the AC power grid and the power supply system, thereby preventing interference from the AC power grid from entering the power supply system, and also preventing interference from the power supply system from entering the AC power grid; the rectifier filtering circuit is electrically connected to the EMC filtering circuit and is used to rectify the AC power after the EMC filtering circuit to obtain the pulsed DC power or stable DC power.

[0012] In one embodiment of this application, the sampling circuit includes an input voltage information sampling circuit, a resonant capacitor voltage or current information sampling circuit, and an output voltage or current information sampling circuit, wherein: the input voltage information sampling circuit is electrically connected to the input circuit and is used to sample input voltage information; the resonant capacitor voltage or current information sampling circuit is electrically connected to the power conversion circuit and is used to sample resonant capacitor voltage or current information; the output voltage or current information sampling circuit is electrically connected to the output circuit and is used to sample output voltage information or output current information.

[0013] In one embodiment of this application, the drive circuit may be independent, integrated with a power switch, or integrated with a controller.

[0014] In one embodiment of this application, the controller may be a digital signal processor, a microcontroller unit, or a field-programmable gate array.

[0015] In one embodiment of this application, when the power system is under no-load or light-load conditions, the controller controls the drive circuit to generate a pulse width modulation pulse beam when the input voltage of the power conversion circuit is within a preset phase range. The center value of the preset phase range is 90 degrees (assuming that each half AC cycle is 0 to 180 degrees, and a complete AC cycle is divided into two 0 to 180 degrees).

[0016] In one embodiment of this application, the preset phase range includes a first boundary value and a second boundary value, the first boundary value being smaller than the second boundary value, the pulse width modulation pulse beam starting from the first boundary value and ending at the second boundary value; the duty cycle of the pulse width modulation pulse beam gradually increases as the phase of the input voltage moves from the first boundary value to the center value, and gradually decreases as the phase of the input voltage moves from the center value to the second boundary value.

[0017] According to another aspect of this application, a power supply system is provided, the power supply system including a main circuit, a drive circuit and a controller, wherein: the power conversion circuit in the main circuit can perform a single-stage power factor correction function; the controller is electrically connected to the drive circuit and is used to control the drive circuit, so that the drive circuit drives the power conversion circuit to achieve active power factor correction, electrical isolation and voltage conversion; when the power supply system is under no-load or light-load conditions, the controller generates a pulse width modulation pulse beam when the input voltage of the power conversion circuit is within a preset phase range, the center value of the preset phase range is 90 degrees (assuming that each half AC cycle is 0 to 180 degrees, and a complete AC cycle is divided into two 0 to 180 degrees).

[0018] In one embodiment of this application, the preset phase range includes a first boundary value and a second boundary value, the first boundary value being smaller than the second boundary value, the pulse width modulation pulse beam starting from the first boundary value and ending at the second boundary value; the duty cycle of the pulse width modulation pulse beam gradually increases as the phase of the input voltage moves from the first boundary value to the center value, and gradually decreases as the phase of the input voltage moves from the center value to the second boundary value.

[0019] In one embodiment of this application, the preset phase range is 0 degrees to 180 degrees (assuming that each half AC cycle is 0 to 180 degrees, and a complete AC cycle is divided into two 0 to 180 degrees).

[0020] According to the embodiments of this application, the power system controls and drives the LLC resonant converter circuit based on the sampling results of the main circuit to realize active power factor correction, electrical isolation and voltage conversion functions. This reduces the number of power devices used, lowers the cost, reduces the number of power conversion stages, saves a lot of power devices and magnetic components, reduces the size and improves efficiency. It is also beneficial to reduce heat dissipation costs and size. The system operates in a soft-switching state under all operating conditions, which is conducive to high frequency operation. Attached Figure Description

[0021] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0022] Figure 1 A schematic structural block diagram of a power supply system according to an embodiment of this application is shown.

[0023] Figure 2 A comparison diagram is shown between the control strategy of the conventional LLC resonant converter circuit and the control strategy of the LLC resonant converter circuit in this application.

[0024] Figure 3 A schematic structural block diagram of a power supply system according to an embodiment of this application is shown.

[0025] Figure 4 An exemplary schematic diagram of a resonant inductor in a power conversion circuit of a power system according to an embodiment of this application is shown.

[0026] Figure 5 An exemplary schematic diagram of a rectifier circuit and an output circuit in a power conversion circuit of a power system according to an embodiment of this application is shown.

[0027] Figure 6 A schematic circuit diagram of the main circuit in a power supply system according to an embodiment of this application and block diagrams of other circuits are shown.

[0028] Figure 7 Another schematic circuit diagram of the main circuit in a power supply system according to an embodiment of this application is shown, along with block diagrams of other circuits.

[0029] Figure 8 A schematic circuit diagram showing another example of the main circuit in a power supply system according to an embodiment of this application is provided.

[0030] Figure 9 This diagram illustrates the burst mode control of a power conversion circuit in a conventional power supply system.

[0031] Figure 10 The diagram shows the unloaded bus voltage and the loaded bus voltage.

[0032] Figure 11 A schematic diagram of burst mode control of a power conversion circuit in a power supply system according to an embodiment of this application is shown.

[0033] Figure 12 This diagram illustrates a power conversion circuit controlling the generation of a pulse width modulation pulse beam in a power supply system according to an embodiment of the present application.

[0034] Figure 13 A schematic structural block diagram of a power supply system according to another embodiment of this application is shown. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this application more apparent, exemplary embodiments according to this application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of this application, and not all of the embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein. Based on the embodiments of this application described herein, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of this application.

[0036] Existing power supply systems generally include a main circuit, a drive circuit, and a controller. The power conversion circuit in the main circuit is either a flyback single-stage PFC power converter or a two-stage converter circuit consisting of a PFC power stage and a DC / DC transformer-isolated voltage regulating power stage. The former has advantages such as simple hardware circuitry, fewer power devices, significant cost advantages, high system gain, simple control, and suitability for wide voltage input / output applications. Its disadvantages include the need for energy storage in the transformer due to the flyback topology, low core utilization (the core only operates in the first quadrant), unsuitability for high power applications, low power density, difficulty in miniaturization, and high switching losses due to hard switching or quasi-resonant mode power switches, limiting further efficiency improvements and hindering high-frequency operation. The latter has advantages such as separate PFC power processing from DC / DC isolation power processing, relatively simple control logic, and suitability for high-power applications. Its disadvantages include multi-stage conversion, difficulty in improving efficiency, complex hardware circuitry, numerous power devices, low power density, difficulty in miniaturization, and high cost.

[0037] Based on this, this application provides a power supply system, which will be described below with reference to the accompanying drawings.

[0038] Figure 1 A schematic structural block diagram of a power supply system 100 according to one embodiment of this application is shown. Figure 1 As shown, the power supply system 100 includes a main circuit 110, a sampling circuit 120, a drive circuit 130, and a controller 140. Specifically: the power conversion circuit in the main circuit 110 includes an LLC resonant converter circuit; the sampling circuit 120 is electrically connected to a portion of the main circuit 110 and is used to sample the input signal, resonant capacitor signal, and output signal of the main circuit 110; the controller 140 is electrically connected to the sampling circuit 120 and the drive circuit 130, and is used to control the drive circuit 130 based on the information sampled by the sampling circuit 120, so that the drive circuit 130 drives the LLC resonant converter circuit to achieve active power factor correction.

[0039] In the embodiments of this application, the power conversion circuit in the main circuit 110 includes an LLC resonant converter circuit. The controller 140 controls the drive circuit 130 based on the information sampling results of the main circuit 110 by the sampling circuit 120, so that the drive circuit 130 drives the LLC resonant converter circuit to realize the functions of active power factor correction (APFC), electrical isolation, and voltage conversion. Compared with the flyback single-stage PFC power conversion circuit in the main circuit 110 of the existing power system 100 described above, the power conversion circuit in the main circuit 110 of the power system 100 of this application has the advantages of the LLC resonant transformer not storing energy, the magnetic core operating in the first and third quadrants, doubling the magnetic core utilization rate, making it suitable for magnetic integration, high-power applications, high power density, and easy miniaturization. In addition, the power switch operates in a soft-switching state, with low switching loss and high efficiency, making it suitable for high-frequency applications. Compared to the two-stage conversion circuit of the main circuit 110 of the existing power system 100 described above, which consists of a PFC power stage and a DC / DC transformer isolation voltage regulation power stage, the power conversion circuit in the main circuit 110 of the power system 100 of this application has a simple hardware circuit, eliminates the PFC power stage, has fewer power devices, has a cost advantage, and performs APFC, electrical isolation, voltage conversion and other functions in a single stage. Since the power conversion stage is reduced by half, the efficiency is high, the power density is high, and it is suitable for miniaturization.

[0040] Therefore, the power system 100 according to the embodiment of this application controls the LLC resonant converter circuit to realize active power factor correction, electrical isolation and voltage conversion functions based on the sampling results of the sampling circuit 120 on the main circuit 110. This reduces the number of power devices used, lowers the cost, reduces the number of power conversion stages, saves a lot of power devices and magnetic components, reduces the size, improves efficiency, helps reduce heat dissipation costs and size, and operates in a soft-switching state under all operating conditions, which is conducive to high frequency.

[0041] In the embodiments of this application, the control strategy of the controller 140 may also differ from that of the traditional LLC resonant converter circuit, in order to solve the problem that the narrow gain of the traditional LLC resonant converter circuit is not suitable for wide voltage input and output. The following will be combined with... Figure 2 To describe.

[0042] Figure 2 A comparison diagram is shown between the control strategy of a conventional LLC resonant converter circuit and the control strategy of the LLC resonant converter circuit in this application. (See diagram for reference.) Figure 2As shown in Figure 210, the input voltage of a traditional LLC resonant converter circuit is a relatively stable DC voltage. The control strategy of the resonant converter circuit in this application allows the input voltage to be a pulsating DC voltage (while also being a stable DC voltage, thus compatible with traditional LLC resonant converter circuits), as shown in Figure 220. The control strategy of traditional LLC resonant converter circuits is generally frequency conversion control, typically operating only near the resonant frequency. The voltage gain range of the converter is very narrow, making it unable to operate under wide voltage input / output conditions, thus failing to perform PFC functionality. The control strategy of the LLC resonant converter circuit in this application allows it to operate in a wide frequency range, both near and far from the resonant frequency (greater or less than the resonant frequency), allowing for large frequency variations and thus a large voltage gain range. This enables the LLC resonant converter circuit to maintain zero voltage switching (ZVS) characteristics under a wide range of input / output voltage conditions, operating with high efficiency while also fulfilling PFC functionality.

[0043] In the embodiments of this application, the main circuit 110 further includes an input circuit, a filter circuit, a power conversion circuit, and an output circuit, wherein: the input circuit includes an AC input interface for receiving AC power; the filter circuit is electrically connected to the input circuit for filtering and rectifying the AC signal to obtain pulsed DC power or stable DC power; the power conversion circuit is electrically connected to the filter circuit for inverting the pulsed DC power or stable DC power into high-frequency AC power, and then isolating, transforming, rectifying, and filtering the high-frequency AC power into low-voltage DC power; the output circuit is currently connected to the power conversion circuit, and the output circuit includes a DC power output interface for performing output stage processing on the low-voltage DC power to obtain the output of the power system 100.

[0044] The filtering circuit includes an electromagnetic compatibility (EMC) filter circuit and a rectifier filter circuit. The EMC filter circuit is electrically connected to the input circuit and is used to perform EMC filtering on the AC power grid and the power supply system, thereby preventing interference from the AC power grid from entering the power supply system and simultaneously preventing interference from the power supply system from entering the AC power grid. The rectifier filter circuit is electrically connected to the EMC filter circuit and is used to rectify the AC power after the EMC filter circuit to obtain pulsed DC power or stable DC power.

[0045] Accordingly, the sampling circuit 120 may further include an input voltage information sampling circuit, a resonant capacitor voltage or current information sampling circuit, and an output voltage and current information sampling circuit, wherein: the input voltage information sampling circuit is electrically connected to the input circuit and is used to sample input voltage information; the resonant capacitor voltage or current information sampling circuit is electrically connected to the power conversion circuit and is used to sample resonant capacitor voltage or current information; and the output voltage and current information sampling circuit is electrically connected to the output circuit and is used to sample output voltage information or output current information.

[0046] The following is combined Figures 3 to 8 To describe a more specific structure of the power supply system according to embodiments of this application.

[0047] Figure 3 A schematic structural block diagram of a power supply system 300 according to one embodiment of this application is shown. Figure 3 As shown, the power supply system 300 includes an input circuit and an EMC filter circuit 310, a rectifier filter circuit 320, a resonant (LLC topology) single-stage PFC power conversion circuit 330 (i.e., the power conversion circuit including the LLC resonant converter circuit mentioned above), and an output circuit 340, which constitute the main circuit described above. The power supply system 300 also includes an input voltage information sampling circuit 350, a resonant capacitor voltage or current information sampling circuit 360, and an output voltage and current information sampling circuit 370, which constitute the sampling circuit described above. The power supply system 300 also includes a drive circuit 380 and a controller 390.

[0048] In the embodiments of this application, the input circuit in the input circuit and EMC filter circuit 310 includes an AC input interface, such as a 110V / 220VAC AC input interface (full voltage range: 85VAC-265VAC); the EMC filter circuit is a filter added to meet electromagnetic compatibility regulations such as radiation and conduction, including but not limited to common-mode inductors, differential-mode inductors, X capacitors, Y capacitors, etc. The rectifier filter circuit 320 rectifies the AC power into unidirectional pulsating DC power or stable DC power, facilitating processing by subsequent circuits, and includes but not limited to diodes, rectifier bridges, capacitors, etc. The resonant (LLC topology) single-stage PFC power converter circuit 330 inverts pulsating or stable DC power into high-frequency AC power. Using a resonant circuit, it transmits the voltage to the secondary side after isolation and transformation by a high-frequency transformer, where it is rectified and filtered to become low-voltage DC power. It features APFC, electrical isolation, and voltage conversion functions. This circuit includes, but is not limited to, transformers, metal-oxide-semiconductor field-effect transistors (MOS), gallium nitride (GaN) transistors, diodes, and capacitors. The output circuit 340 includes a DC output interface for various protocol processing, protection processing, and output voltage regulation feedback processing. This circuit includes, but is not limited to, MOS, diodes, DC / DC converters, protocol chips, and interfaces.

[0049] In the embodiments of this application, the input voltage information sampling circuit 350 collects information about the input AC current, including, but not necessarily all, information such as amplitude, peak value, phase, and zero-crossing point. The resonant capacitor voltage or current information sampling circuit 360 collects the voltage or current information of the resonant capacitor in the LLC resonant topology, including, but not necessarily all, information such as amplitude, peak value, phase, and zero-crossing point of the resonant capacitor voltage or current. The output voltage and current information sampling circuit 370 collects output voltage information or output current information and performs isolation feedback. The output voltage information includes at least one of the following: the amplitude, peak value, phase, and zero-crossing point of the output voltage of the output circuit 340. The output current information includes at least one of the following: the amplitude, peak value, phase, and zero-crossing point of the output current of the output circuit 340. The drive circuit 380 can be independent, integrated with the power switch, or integrated with the controller. The controller 390 is the core logic control circuit, which can be implemented by a pure analog chip or hardware circuit, or by a software-programmable digital chip, and is responsible for the logic control of the entire system. For example, controller 390 may include a digital signal processor (DSP), a microprogrammed control unit (MCU), or a field programmable gate array (FPGA).

[0050] In the embodiments of this application, the resonant (LLC topology) single-stage PFC power conversion circuit 330 can be a half-bridge LLC resonant converter circuit or a full-bridge LLC resonant converter circuit. In the embodiments of this application, the resonant inductor in the resonant (LLC topology) single-stage PFC power conversion circuit 330 can be a discrete resonant inductor or a magnetically integrated resonant inductor (a magnetically integrated resonant inductor refers to a resonant inductor integrated with the main transformer) (e.g. Figure 4 (As shown). In the embodiments of this application, the rectifier circuit in the resonant (LLC topology) single-stage PFC power conversion circuit 330 can be a bridge rectifier circuit or a full-wave rectifier circuit; it can be a diode rectifier circuit or a synchronous rectifier circuit composed of power switching semiconductor devices (such as MOS, GaN, etc.). Figure 5 shown). Figure 6 and Figure 7 The power supply system 300 (or 100) according to the embodiments of this application is a circuit diagram example of the main circuit (other circuit parts are still represented by block diagrams). Figure 8This is an example of a circuit diagram of the main circuit portion of the power system 300 (or 100) according to an embodiment of this application. The component symbols and connections in the above block diagrams and circuit diagrams are typical representative devices and do not necessarily represent actual devices and electrical connections.

[0051] The following is combined Figures 9 to 12 This application describes a burst mode control scheme for the controller in the power system 300 (or 100) according to an embodiment of the present application when the power system 300 is under no-load or light-load conditions.

[0052] In traditional Burst Mode schemes, the Pulse Width Modulation (PWM) pulse beam is generated randomly. A PWM pulse beam is generated when the output voltage drops to a threshold to stabilize the output voltage, regardless of the phase of the input AC signal. Figure 9 As shown. This will cause the following problem: the bus voltage after rectification in a single-stage PFC scheme is a pulsating, wavy DC under full or heavy load (e.g., Figure 10 The DC voltage shown is 1010 (the waveform of the steamed bun), while under no-load or light-load conditions, it is a relatively stable DC voltage (such as...). Figure 10 The stable DC voltage shown is 1020, but this relatively stable DC voltage does not have the ability to carry a load. Once a load is carried (when a PWM pulse beam occurs), the voltage will be quickly pulled up to the instantaneous value of the input AC voltage at this time, that is, the ripple voltage corresponding to the current phase angle. If the current phase angle is far from 90 degrees, that is, near the peak voltage, the bus voltage will be quickly pulled down from the high voltage, causing large peak current stress and transformer noise. When the current phase angle is near 90 degrees, that is, near the peak voltage, the bus voltage is equal to the instantaneous value and will not be pulled down.

[0053] Based on this, in the embodiments of this application, the controller 390 controls the drive circuit 380 to generate a PWM pulse beam when the input voltage of the power conversion circuit 330 is within a preset phase range. The center value of the preset phase range is 90 degrees (assuming each half AC cycle is 0 to 180 degrees, and a complete AC cycle is divided into two 0 to 180 degree intervals). In this embodiment, the Burst Mode PWM pulse beam is generated only when the instantaneous value of the input voltage of the power conversion circuit 330 reaches near its peak value, such as... Figure 11 As shown, this can effectively reduce current peak and transformer noise problems, reduce current stress, and avoid extreme situations such as power device explosion due to excessive stress.

[0054] In a further embodiment of this application, the aforementioned preset phase range includes a first boundary value and a second boundary value, wherein the first boundary value is smaller than the second boundary value, the PWM pulse beam starts at the first boundary value and ends at the second boundary value; the duty cycle of the PWM pulse beam gradually increases as the phase of the input voltage moves from the first boundary value to the aforementioned center value, and gradually decreases as the phase of the input voltage moves from the aforementioned center value to the second boundary value. The following is in conjunction with... Figure 12 To illustrate, for example. Figure 12 As shown, the PWM pulse beam is generated when the phase angle of the input voltage of the power conversion circuit 330 is within the range of 80 to 100 degrees (assuming each half AC cycle is 0 to 180 degrees, and a complete AC cycle is divided into two 0 to 180 degree ranges; the 80 to 100 degree range here is just an example, and in reality, the controller 390 automatically controls the size of this range according to the control strategy based on the output load, which can cover 0 to 180 degrees). During the process of the phase angle of the input voltage of the power conversion circuit 330 increasing from 80 to 90 degrees, the duty cycle of the PWM pulse beam gradually increases; during the process of the phase angle of the input voltage of the power conversion circuit 330 increasing from 90 to 100 degrees, the duty cycle of the PWM pulse beam gradually decreases. That is, the duty cycle of each Burst Mode PWM pulse beam gradually increases from small to large and then gradually decreases to small, i.e., soft entry and soft exit, avoiding sudden changes in transformer current and effectively reducing noise generation.

[0055] The above exemplarily illustrates a power supply system according to an embodiment of this application. Based on the above description, the power supply system controls the LLC resonant converter circuit to achieve active power factor correction, electrical isolation, and voltage conversion functions based on the sampling results of the main circuit information from the sampling circuit. This reduces the number of power devices used, lowers costs, reduces the number of power conversion stages, saves a large number of power devices and magnetic components, reduces size, improves efficiency, and helps reduce heat dissipation costs and size. It operates in a soft-switching state under all operating conditions, which is beneficial for high-frequency operation.

[0056] The following is combined Figure 13 Here is a schematic structural block diagram describing a power supply system 1300 according to another embodiment of this application. For example... Figure 13As shown, the power supply system 1300 includes a main circuit 1310, a drive circuit 1320, and a controller 1330. The power conversion circuit in the main circuit 1310 includes a single-stage PFC circuit. The controller 1330 is electrically connected to the drive circuit 1320 and is used to control the drive circuit 1320 so that the drive circuit 1320 drives the power conversion circuit to achieve active power factor correction, electrical isolation, and voltage conversion. When the input voltage of the power conversion circuit is within a preset phase range, the controller 1330 generates a pulse width modulation pulse beam. The center value of the preset phase range is 90 degrees (assuming that each half AC cycle is 0 to 180 degrees, and a complete AC cycle is divided into two 0 to 180 degrees).

[0057] The power system 1300 according to the embodiments of this application is similar to the power systems 100 and 300 described above, except that the power conversion circuit in the main circuit 1310 of the power system 1300 is not necessarily a single-stage PFC power conversion circuit including an LLC resonant converter circuit, but any single-stage PFC power conversion circuit is sufficient. This is because the power system 1300 focuses on solving the problems of traditional Burst Mode solutions (as described above in conjunction with...). Figures 9 to 12 As described, it optimizes the control strategy of a single-stage PFC power conversion circuit under no-load or light-load conditions. The Burst Mode PWM pulse beam is generated only when the instantaneous input AC value reaches its peak value, effectively reducing current peaks and transformer noise, minimizing current stress, and preventing extreme situations such as power device failure due to excessive stress. Those skilled in the art can understand the structure and operation of the power system 1300 based on the foregoing description; for brevity, further details are omitted here.

[0058] Based on the above description, the power supply system according to the embodiments of this application controls the LLC resonant converter circuit to achieve active power factor correction, electrical isolation, and voltage conversion functions based on the sampling results of the main circuit information from the sampling circuit. This reduces the number of power devices used, lowers costs, reduces the number of power conversion stages, saves a large number of power devices and magnetic components, reduces size, and improves efficiency. It also helps reduce heat dissipation costs and size. The system operates in a soft-switching state under all operating conditions, which is beneficial for high-frequency operation. Furthermore, the power supply system according to the embodiments of this application optimizes the control strategy of the single-stage PFC power conversion circuit under no-load or light-load conditions. The BurstMode PWM pulse beam is generated only when the instantaneous value of the input AC reaches its peak value, which can effectively reduce current peaks and transformer noise, reduce current stress, and avoid extreme situations such as power device overload leading to device failure.

[0059] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.

[0060] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0061] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed.

[0062] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of this application may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0063] Similarly, it should be understood that, in order to streamline this application and aid in understanding one or more of the various inventive aspects, features of this application may sometimes be grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of this application. However, this approach should not be construed as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, its inventive point lies in solving the corresponding technical problem with features fewer than all features of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of this application.

[0064] Those skilled in the art will understand that, apart from the mutual exclusion of features, all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or apparatus so disclosed can be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0065] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0066] The various component embodiments of this application can be implemented in hardware, or in software running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions according to the embodiments of this application. This application can also be implemented as an apparatus program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such an implementation of this application can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0067] It should be noted that the above embodiments are illustrative of this application and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. This application can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0068] The above description is merely a specific embodiment or illustration of the embodiments of this application. The scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. The scope of protection of this application shall be determined by the scope of the claims.

Claims

1. A power supply system, characterized in that, The power supply system includes a main circuit, a sampling circuit, a drive circuit, and a controller, wherein: The main circuit includes an LLC resonant converter circuit; The sampling circuit is electrically connected to the main circuit and is used to sample the input signal, resonant capacitor signal and output signal of the main circuit. The controller is electrically connected to the sampling circuit and the driving circuit, and is used to control the driving circuit based on the information sampled by the sampling circuit, so that the driving circuit drives the LLC resonant converter circuit to achieve active power factor correction, electrical isolation and voltage conversion; The controller's control strategy enables the input voltage of the LLC resonant converter circuit to include a pulsed DC voltage, and enables the LLC resonant converter circuit to operate in a wide frequency range, both near and far from the resonant frequency.

2. The power supply system according to claim 1, characterized in that, The information sampled by the sampling circuit includes either the input voltage information of the main circuit, the resonant capacitor voltage or current information, or the output voltage information and output current information, wherein: The input voltage information includes at least one of the following: the amplitude, peak value, phase, and zero-crossing point of the input voltage of the main circuit; The resonant capacitor voltage or current information includes at least one of the following: the amplitude, peak value, phase, and zero-crossing point of the resonant capacitor voltage or current of the main circuit; The output voltage information includes at least one of the following: the amplitude, peak value, phase, and zero-crossing point of the output voltage of the main circuit; The output current information includes at least one of the following: the amplitude, peak value, phase, and zero-crossing point of the output current of the main circuit.

3. The power supply system according to claim 1 or 2, characterized in that, The LLC resonant converter circuit includes a half-bridge LLC resonant converter circuit or a full-bridge LLC resonant converter circuit; The resonant inductor in the LLC resonant converter circuit includes a discrete resonant inductor or a magnetically integrated resonant inductor, wherein the magnetically integrated resonant inductor refers to the resonant inductor being integrated with the main transformer. The rectifier circuit in the LLC resonant converter circuit includes a bridge rectifier circuit or a full-wave rectifier circuit. The rectifier circuit in the LLC resonant converter circuit includes a diode rectifier circuit or a synchronous rectifier circuit composed of power switching semiconductor devices.

4. The power supply system according to claim 1 or 2, characterized in that, The main circuit includes an input circuit, a filter circuit, a power conversion circuit, and an output circuit, wherein: The input circuit includes an AC input interface for receiving AC power; The filter circuit is electrically connected to the input circuit and is used to filter and rectify the AC power to obtain pulsed DC power or stable DC power. The power conversion circuit includes the LLC resonant converter circuit, which is electrically connected to the filter circuit. It is used to invert the pulsed DC or stable DC into high-frequency AC, and to isolate, transform, rectify and filter the high-frequency AC into low-voltage DC. The output circuit is electrically connected to the power conversion circuit. The output circuit includes a DC output interface for processing the low-voltage DC power at the output stage to obtain the output of the power supply system.

5. The power supply system according to claim 4, characterized in that, The filtering circuit includes an electromagnetic compatibility filtering circuit and a rectifier filtering circuit, wherein: The electromagnetic compatibility filtering circuit is electrically connected to the input circuit and is used to perform electromagnetic compatibility filtering on the AC power from the AC power grid and the power supply system, thereby preventing interference from the AC power grid from entering the power supply system, and at the same time preventing interference from the power supply system from entering the AC power grid. The rectifier filter circuit is electrically connected to the electromagnetic compatibility filter circuit and is used to rectify the AC power after the electromagnetic compatibility filter circuit to obtain the pulsed DC power or stable DC power.

6. The power supply system according to claim 4, characterized in that, The sampling circuit includes an input voltage information sampling circuit, a resonant capacitor voltage or current information sampling circuit, and an output voltage or current information sampling circuit, wherein: The input voltage information sampling circuit is electrically connected to the input circuit and is used to sample input voltage information; The resonant capacitor voltage or current information sampling circuit is electrically connected to the power conversion circuit and is used to sample the resonant capacitor voltage or current information. The output voltage or current information sampling circuit is electrically connected to the output circuit and is used to sample output voltage information or output current information.

7. The power supply system according to claim 4, characterized in that, When the power system is under no-load or light-load conditions, the controller controls the drive circuit to generate a pulse width modulation pulse beam when the input voltage of the power conversion circuit is within a preset phase range. The center value of the preset phase range is 90 degrees, where each half AC cycle is 0 to 180 degrees, and a complete AC cycle is divided into two 0 to 180 degree intervals.

8. The power supply system according to claim 7, characterized in that, The preset phase range includes a first boundary value and a second boundary value, the first boundary value is smaller than the second boundary value, and the pulse width modulation pulse beam starts from the first boundary value and ends at the second boundary value; The duty cycle of the pulse width modulation pulse beam gradually increases as the phase of the input voltage moves from the first boundary value to the center value, and gradually decreases as the phase of the input voltage moves from the center value to the second boundary value.

9. A power supply system, characterized in that, The power supply system includes a main circuit, a drive circuit, and a controller, wherein: The power conversion circuit in the main circuit can perform single-stage power factor correction. The controller is electrically connected to the drive circuit and is used to control the drive circuit so that the drive circuit drives the power conversion circuit to achieve active power factor correction, electrical isolation and voltage conversion; The control strategy of the controller enables the input voltage of the power conversion circuit to include pulsed DC voltage, and enables the power conversion circuit to operate in a wide frequency range, both near and far from the resonant frequency. When the power system is under no-load or light-load conditions, the controller generates a pulse width modulation pulse beam when the input voltage of the power conversion circuit is within a preset phase range. The center value of the preset phase range is 90 degrees, where each half AC cycle is 0 to 180 degrees, and a complete AC cycle is divided into two 0 to 180 degree intervals.

10. The power supply system according to claim 9, characterized in that, The preset phase range includes a first boundary value and a second boundary value, the first boundary value is smaller than the second boundary value, and the pulse width modulation pulse beam starts from the first boundary value and ends at the second boundary value; The duty cycle of the pulse width modulation pulse beam gradually increases as the phase of the input voltage moves from the first boundary value to the center value, and gradually decreases as the phase of the input voltage moves from the center value to the second boundary value.

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