Power supply circuit based on three-phase power supply and method for implementing PFC / boost / buck power supply therein

Abstract

This application discloses a power supply circuit based on a three-phase power supply, and a method for simultaneously achieving power factor tracking and dynamic boost / buck conversion. The power supply circuit includes an information acquisition module and a power supply circuit unit, the power supply circuit unit includes three circuit groups formed by three phases connected to a three-phase power supply, and a control center for controlling the operating state of the three circuit groups. Each circuit group includes an input rectifier module, inductor, capacitor, switch and its controller, transformer, and output half-wave rectifier module. The output terminals of the three circuit groups included in the power supply circuit unit are connected in parallel or in series to solve the ripple problem and improve power conversion efficiency. The aforementioned power supply circuit adjusts the peak value of the input current at a high frequency, further adjusting the switching frequency and duty cycle, and controlling the charging and discharging time of the inductor to achieve power factor tracking, while simultaneously enabling dynamic adjustment of boost and buck voltage to meet load demands, effectively reduce costs, have low energy loss, and have high power conversion efficiency.

Description

Technical Field

[0005] ,

[0004] , ,

[0001] This application relates to the technical field of power supplies, and particularly to power supply circuit technologies in high-power scenarios.

Background Art

[0002] In the prior art, a power supply module applied to a high-power scenario (generally, a case where it exceeds 200 W is referred to as high power) generally includes a two-stage circuit of a front stage and a rear stage. The front stage usually uses various topology circuits based on a Boost rectifier or equivalent to a Boost circuit to achieve power factor correction (also referred to as PFC). As the mainstream PFC topology methods, there are three-phase three-wire three-level VIENNA (for example, including two-system interleaved parallel three-phase three-wire three-level VIENNA, single-phase interleaved three-phase three-wire three-level VIENNA), totem pole topology circuit, Boost circuit (for example, including an interleaved Boost circuit applied to a single-phase power supply), etc.

[0003] On the other hand, the DC-DC method in the rear stage generally realizes step-down or stabilization by a circuit topology method based on a full bridge. For example, it includes two sets of interleaved series two-level full bridge LLC, two sets of interleaved parallel two-level full bridge LLC, three-level phase shift full bridge, two sets of two-level LLC full bridge series, two sets of two-level three-phase interleaved LLC series, three-level LLC half / full bridge, etc.

[0004] FIG. 1 shows the front-stage PFC topology circuit of a power supply module in the prior art. Specifically, it is a connection schematic diagram of a three-phase three-wire three-level VIENNA circuit. FIG. 2 shows the rear-stage DC / DC topology circuit of a power supply module in the prior art, which realizes voltage stabilization / insulation of the power supply module. Specifically, it is a connection schematic diagram of two sets of interleaved series two-level full bridge LLC.

[0005] Consequently, conventional power modules require a two-stage circuit, consisting of a pre- and post-stage, to achieve power conversion and transmission. This results in a large number of components and complex circuit connections, leading to problems such as high cost, significant energy loss, low stability, low power conversion efficiency, and limited expandability. Furthermore, increasing the capacitance of the output capacitor is necessary to solve the ripple problem. [Overview of the Initiative]

[0006] One objective of this application is to provide a power supply circuit based on a three-phase power supply, and a method for achieving power factor tracking and boost / buck voltage using said power supply circuit, thereby solving the problems of the complex component connections, low power conversion efficiency, and limited expandability of conventional power supply circuits, as well as the problem of large frequency ripple caused by single-stage circuits.

[0007] This application provides a power supply circuit based on a three-phase power supply, the power supply circuit including an information acquisition module and a power supply circuit unit, the power supply circuit unit including three circuit groups formed by three phases A / B / C connected to the three-phase power supply, and a control center for controlling the operating state of the three circuit groups.

[0008] The circuit group includes an input rectifier module, an inductor, a capacitor, a switch and its controller, a transformer, and an output half-wave rectifier module.

[0009] One end of the inductor is connected to the terminal of one phase of the three-phase power supply, and the other end of the inductor is connected to one end of the switch and one end of the capacitor.

[0010] The other end of the capacitor is connected to one end of the primary winding of the transformer, and the other end of the primary winding of the transformer and the other end of the switch are connected to the fire terminal or neutral terminal of the other phase.

[0011] The two output terminals of the secondary winding of the transformer are output terminals for supplying power to the circuit group, and the terminal corresponding to one end of the capacitor connected to the primary winding is connected to the output half-wave rectifier module.

[0012] The output terminals of the three circuit groups connected to the three-phase power supply, which are included in the aforementioned power supply circuit unit, are connected in parallel.

[0013] This application further provides a method for simultaneously achieving power factor tracking and dynamic boost / buck adjustment using the three-phase power supply circuit described above.

[0014] Step S1 involves obtaining the current actual input current, input voltage, output voltage, and output current values ​​at high frequency.

[0015] Step S2 involves comparing the acquired current actual output power with the target output power required for the connected load,

[0016] Step S3 involves adjusting the peak value of the input current at a high frequency based on the comparison result between the current actual output power and the target output power.

[0017] Step S4 involves determining the value of the target input current at a high frequency based on the peak value of the input current and the phase information of the current input.

[0018] Step S5 involves comparing the current actual input current value with the target input current value, and determining the duty cycle frequency adjustment command information for the switch at a high frequency based on the comparison result.

[0019] Step S6 includes controlling the charging and discharging time of an inductor in the power supply circuit by having a switch in the power supply circuit execute the command information at a high frequency so that the current actual input current value of the power supply circuit is as close as possible to the target input current value.

[0020] Compared to prior art, the power supply circuit based on the three-phase power supply of this application includes an information acquisition module and a power supply circuit unit, the power supply circuit unit includes three circuit groups formed by three phases connected to the three-phase power supply, and a control center for controlling the operating state of the three circuit groups, the circuit groups including an input rectifier module, inductors, capacitors, switches and their controllers, transformers, and an output half-wave rectifier module.

[0021] A method for simultaneously achieving power factor tracking and dynamic boost / buck adjustment in response to output requirements based on the power supply circuit of this application involves adjusting the peak value of the input current at a high frequency, further adjusting the frequency and duty cycle of the switch, and controlling the charging and discharging time of the inductor. This enables power factor tracking and dynamic boost and buck adjustment in response to the magnitude of the input voltage and the output voltage requirements of the power supply circuit, thereby meeting load demands.

[0022] This application describes how a single-stage circuit can achieve the functions of the prior art PFC+DC-DC converter, including rectification, power factor tracking, dynamic boosting, bucking, and high-frequency isolation, while significantly reducing the number of components used and improving power conversion efficiency. However, single-stage circuits suffer from the problem of relatively large frequency ripple.

[0023] Based on the operating principle of the circuit group included in the power supply circuit, parallel combination of output terminals is possible between the circuit groups.

[0024] This application solves the problem of high frequency ripple caused by single-stage circuits by using a power supply circuit based on a three-phase power supply, performing power factor tracking for each phase of the three-phase power supply, and then combining the output terminals of the three-phase power supply by connecting them in parallel.

[0025] Furthermore, it avoids the problem of output power imbalance between circuit groups that can occur when multiple circuit groups are combined in parallel. [Brief explanation of the drawing]

[0026] [Figure 1] It is a schematic connection diagram of a three-phase three-wire three-level VIENNA circuit, which is the front-stage PFC topology circuit of a power module circuit in the prior art.

[0027] [Figure 2] It is a schematic connection diagram of two sets of interleaved series two-level full-bridge circuits, which are the rear-stage DC / DC topology circuits of a power module in the prior art.

[0028] [Figure 3] It is a schematic connection diagram of a circuit group included in a power circuit unit in an embodiment of the present application.

[0029] [Figure 4] It is a schematic connection diagram of a power circuit based on a three-phase power supply in an embodiment of the present application.

[0030] [Figure 5-1] FIG. 5-1 is a waveform diagram of the input inductor of a power circuit corresponding to the case where the input power supply is a sine wave of a single-phase power supply.

[0031] [Figure 5-2] FIG. 5-2 is a ripple waveform diagram of the output voltage corresponding to FIG. 5-1.

[0032] [Figure 5-3] FIG. 5-3 is a waveform diagram of the input inductor of a power circuit corresponding to the case where the input power supply is a sine wave of a three-phase power supply.

[0033] [Figure 5-4] FIG. 5-4 is a schematic diagram showing a comparison of the ripple waveform of the output voltage corresponding to FIG. 5-3 and the output voltage ripple waveform of FIG. 5-2.

[0034] [Figure 6] It is a flowchart of a method for realizing both power factor tracking and dynamic adjustment of boost / buck in a power circuit in another embodiment of the present application. [Modes for carrying out the invention]

[0035] To enable those skilled in the art to better understand the technical means of this application, the technical means of this application will be clearly and completely described below with reference to the drawings of the embodiments of this application. The embodiments described are only a selection of embodiments of this application, not all embodiments. All other embodiments that can be obtained by those skilled in the art without any creative work based on the embodiments of this application are all within the scope of protection of this application.

[0036] Furthermore, terms such as "first," "second," etc., in the specification, claims, and drawings of this application are for distinguishing similar subjects and do not necessarily indicate a specific order or priority. It should be understood that the data used herein may be rearranged as appropriate so that the embodiments of this application described herein can be carried out in an order other than those illustrated or described herein. Also, the terms "includes," "has," and any variations thereof are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus including a series of steps or units may include other steps or units that are not explicitly shown or are specific to these processes, methods, products, or apparatus, but are not limited to those explicitly shown.

[0037] This application provides a power supply circuit based on a three-phase power supply to solve the problems of conventional power supply circuits, which have high costs due to a large number of components and complex connections, low stability, high energy loss, low conversion efficiency, low expandability, and the presence of output ripple.

[0038] Conventional power supply circuits employ a two-stage circuit (pre-stage and post-stage), with the pre-stage circuit achieving power factor tracking and the post-stage circuit achieving voltage reduction / stabilization.

[0039] The power supply circuit based on a three-phase power supply disclosed in this embodiment includes at least one power supply circuit unit, the power supply circuit unit includes an inductor, a switch and its controller, a capacitor, and a transformer.

[0040] Each power supply circuit unit is provided with three circuit groups connected to a three-phase power supply, and the output terminals of these three circuit groups are connected in parallel to effectively resolve the ripple problem.

[0041] Furthermore, the power supply circuit of this application may include multiple power supply circuit units, in which case a wide range of output voltages / output powers can be achieved by combining the output terminals of the multiple power supply circuit units in series or in parallel.

[0042] This application provides a power supply circuit based on a three-phase power supply to solve the problems of conventional power supply circuits, which are characterized by high cost due to the large number of components and complex connections, low stability, high energy loss, low conversion efficiency, and the presence of output ripple.

[0043] As shown in Figures 3, 4, and 5, this application provides a power supply circuit based on a three-phase power supply, the power supply circuit including an information acquisition module and a power supply circuit unit, the power supply circuit unit including three circuit groups formed by three phases A / B / C connected to the three-phase power supply, and a control center for controlling the operating state of the three circuit groups.

[0044] The circuit group includes an input rectifier module, an inductor, a capacitor, a switch and its controller, a transformer, and an output half-wave rectifier module.

[0045] One end of the inductor is connected to the terminal of one phase of the three-phase power supply, and the other end of the inductor is connected to one end of the switch and one end of the capacitor.

[0046] The other end of the capacitor is connected to one end of the primary winding of the transformer, and the other end of the primary winding of the transformer and the other end of the switch are connected to the fire terminal or neutral terminal of the other phase.

[0047] The two output terminals of the secondary winding of the transformer are output terminals for supplying power to the circuit group, and the terminal corresponding to one end of the capacitor connected to the primary winding is connected to the output half-wave rectifier module.

[0048] The output terminals of the three circuit groups connected to the three-phase power supply, which are included in the aforementioned power supply circuit unit, are connected in parallel.

[0049] Specifically, in this embodiment, the power supply circuit unit includes three circuit groups, each circuit group is connected to each phase of the three-phase power supply, and the power supply circuit can include multiple power supply circuit units, that is, multiple circuit groups can be connected to each phase of the three-phase power supply, and the multiple power supply circuit units operate in the same operating mode or operating state, and the control logic used by the controller to control and adjust the duty cycle and switching frequency of the switches is the same in each circuit group within each power supply circuit unit.

[0050] As shown in Figures 3, 4, and 5, the circuit group includes an input rectifier module, an inductor, a capacitor, a switch and its controller, a transformer, and an output half-wave rectifier module. One end of the inductor is connected to the positive terminal of the power output rectified to correspond to one phase of the three-phase power supply. The other end of the inductor is connected to one end of the switch and one end of the capacitor. The other end of the capacitor is connected to one end of the primary winding of the transformer. The other end of the primary winding of the transformer and the other end of the switch are connected to the negative terminal of the output after rectification in the three-phase power supply. The two output terminals of the secondary winding of the transformer are output terminals for supplying power to the circuit group. The terminal corresponding to one end of the capacitor connected to the primary winding is connected to the output half-wave rectifier module.

[0051] Specifically, each power supply circuit unit includes three circuit groups, and each circuit group is connected to each phase of the three-phase power supply, with two specific connection methods for each phase.

[0052] As shown in Figure 4, in one configuration, the three circuit groups included in the power supply circuit unit are connected to the AB phase, BC phase, and AC phase of the ABC three-phase power supply, respectively. In this case, the effective value of the input voltage supplied to the power supply circuit by the three-phase power supply is 380 volts.

[0053] As shown in Figure 5, in the other method, the three circuit groups included in the power supply circuit unit are connected to phase A and the neutral wire (i.e., AN), phase B and the neutral wire (i.e., BN), and phase C and the neutral wire (i.e., CN), respectively, and in this case, the effective value of the input voltage supplied to the power supply circuit by the three-phase power supply is 220 volts.

[0054] The output terminals of the three circuit groups corresponding to the three-phase power supply, included in the aforementioned power supply circuit unit, are connected in parallel.

[0055] Preferably, the output terminals of the three circuit groups are connected in parallel and then connected to a capacitor.

[0056] Specifically, one phase of the single-phase or three-phase power supply input to each circuit group within the power supply circuit unit is a sinusoidal AC current, which is rectified by a full-bridge rectifier module and then input as a half-wave sine wave to the inductor of the circuit group.

[0057] Since the inductor in the circuit group has a power factor tracking function (see the power factor tracking process described later for details), the output voltage of the circuit group at this time will have a 100Hz fluctuation superimposed on the corresponding DC component. This 100Hz fluctuation is caused by the half-wave sinusoidal input, and the input power changes according to the phase of the half-wave sinusoidal wave.

[0058] When the input voltage becomes zero, the output of the secondary winding of the circuit group also becomes zero, and at this time, the output of the circuit group is supplied only by the output capacitor (e.g., filter capacitor or electrolytic capacitor) connected to the output terminal of the circuit group.

[0059] As a result, the voltage across the output capacitor decreases, reducing the voltage supplied by the circuit group to the load, i.e., the capacitor voltage, and causing a significant ripple problem.

[0060] When three circuit groups are connected to a three-phase power supply simultaneously, the three phases of the three-phase power supply have a phase difference of 120°. As shown in Figure 4, the output terminals of the three circuit groups included in the power supply circuit unit are connected to three output capacitors C1, C2, and C3, respectively. The positive terminals of the three capacitors are connected to each other to form one output terminal of the power supply circuit unit, and the negative terminals are also connected to each other to form the other output terminal of the power supply circuit unit. In other words, the three circuit groups simultaneously charge the three output capacitors connected in parallel, and by connecting the output capacitors C1, C2, and C3 in parallel to the load, power can be supplied to the load, effectively solving the ripple problem.

[0061] Alternatively, the output terminals of the three circuit groups included in the power supply circuit unit may be directly connected in parallel, and then connected to one or a set of output capacitors, with the output capacitors supplying power to the load. This configuration also solves the ripple problem. Here, the output capacitors may be electrolytic capacitors, film capacitors, etc., and their specific form is not limited; it is sufficient that they enable energy storage and that the circuit groups can supply output to the load.

[0062] In this embodiment, the circuit group of this application has a small number of components and high circuit stability, making it possible to directly combine the output terminals of multiple circuit groups in parallel.

[0063] The power factor tracking and dynamic boost / buck methods disclosed in this application control the switches of each circuit group, thereby ensuring equal current flow among circuit groups with multiple output terminals connected in parallel. This prevents large differences in output power between circuit groups, which could damage the device.

[0064] In practice, this application ensures the power conversion efficiency of the power supply circuit while significantly solving the ripple problem by performing power factor tracking for each phase of the three-phase power supply and connecting the output terminals in parallel after dynamically boosting / bucking the voltage.

[0065] Preferably, the control center controls the duty cycle and switching frequency of the switches in the circuit group by transmitting control information to the switches.

[0066] When a switch in a corresponding circuit group is in the ON state, the switch in that circuit group forms a circuit with the connected input power supply of that phase and an inductor, charging the inductor, and the capacitor forms an LC oscillation circuit with the switch and the primary winding of the transformer, and the energy stored in the capacitor moves between the primary winding of the transformer and the capacitor.

[0067] When the switch is in the off state, the connected input power supply of the relevant phase, the inductor, the capacitor, and the primary winding of the transformer form an LLC oscillation circuit. The connected input power supply of the relevant phase and the charged inductor charge the capacitor, and the charged inductor superimposes its own energy on the energy stored on the primary side of the transformer, thereby inducing power to the secondary winding due to the change in the primary current of the transformer.

[0068] Specifically, as shown in Figures 3, 4, and 5, the operating principle and process of one circuit group within a power supply circuit unit connected to a three-phase power supply are as follows:

[0069] The control center transmits control information, including the duty cycle and switching frequency, to the switches, and controls the proportion of time that the switches in the circuit group are in the ON state within the periodic time.

[0070] When a switch in a corresponding circuit group is in the ON state, the switch in that circuit group forms a circuit with the connected input power supply of that phase and an inductor, charging the inductor, and the capacitor forms an LC oscillation circuit with the switch and the primary winding of the transformer.

[0071] When the switch is in the off state, the connected input power supply of the relevant phase, the inductor, the capacitor, and the primary winding of the transformer form an LLC oscillation circuit. The connected input power supply of the relevant phase and the charged inductor charge the capacitor, and the charged inductor superimposes its own energy on the energy stored on the primary side of the transformer, thereby inducing power to the secondary winding due to the change in the primary current of the transformer.

[0072] Specifically, as shown in Figures 3, 4, and 5, the control center controls the on / off frequency and duty cycle of the switches in each of the three circuit groups based on the power supply circuit unit's power requirements at its output terminals.

[0073] As shown in Figure 3, when the switch K of the circuit group is in the ON state, the switch K forms a circuit together with the input power supply and the inductor L, the input power supply charges the inductor L through this circuit, and the capacitor C of the circuit group forms an LC oscillator circuit together with the switch K and the primary winding of the transformer T.

[0074] When switch K is in the off state, the input power supply, inductor L, capacitor C, and the primary winding of transformer T form an LLC oscillator circuit. The connected input power supply and charged inductor L charge capacitor C, and the charged inductor L superimposes its own energy on the energy stored on the primary side of transformer T, thereby inducing power to the secondary winding due to the change in the primary current of the transformer.

[0075] The circuit group disclosed in this embodiment controls the operating state of switch K to charge inductor L, then discharge it to capacitor C and the primary winding of transformer T. As a result, the primary winding of transformer T acquires energy, which is then transmitted to the secondary winding of transformer T, and power is output.

[0076] By controlling the switching frequency and duty cycle of switch K, the charging and discharging time of inductor L and the charging and discharging time of the primary winding inductance of the transformer are controlled, and furthermore, the amount of power output from the secondary winding of the transformer is controlled.

[0077] This embodiment enables power transmission using a power supply circuit with an extremely small number of components compared to conventional technology, achieving low cost, high stability, and high power conversion efficiency.

[0078] Specifically, as shown in Figure 3, the detailed operation process of the circuit group within the power supply circuit unit disclosed in this embodiment is as follows.

[0079] When switch K is ON, the input power supply charges inductor L, and inductor L stores energy. At the moment switch K is turned OFF, inductor L generates a high voltage to prevent abrupt changes in current across its terminals, and transmits power through the new circuit (1) [input power supply + inductor L + capacitor C + transformer T] formed by the turning off of switch K. The input power supply discharges, the primary windings of inductor L and transformer T discharge, capacitor C is charged, and the change in current in the primary winding of transformer T induces power in the secondary winding of transformer T. At this time, the sum of the voltage of the input power supply and the voltage of inductor L is equal to the sum of the voltage of capacitor C and the voltage of the primary winding of transformer T, i.e., V input power supply + VL = VC + VT primary side. Transformer T induces power in its secondary winding, and the secondary winding is output to the output terminal of the power supply circuit unit by the output half-wave rectifier module, supplying power to the load.

[0080] When switch K switches from the off state to the on state, the power supply circuit unit sequentially forms the following circuits and operating processes.

[0081] The power supply circuit charges inductor L by circuit (2) [input power supply + inductor L + switch K], and simultaneously charges capacitor C and the primary winding of transformer T by circuit (1) [input power supply + inductor L + capacitor C + transformer T]. Once capacitor C is fully charged, capacitor C charges the primary winding of transformer T by circuit (3) [capacitor C + transformer T + switch K] to prevent abrupt current changes across its terminals. Since an output half-wave rectifier module is provided in the circuit of the secondary winding of transformer T, at this point transformer T cannot transmit power to the secondary winding. In other words, the primary winding of transformer T and capacitor C form an LC resonant circuit, retaining energy within the circuit. Simultaneously, with switch K in the ON state, the input power supply charges inductor L by circuit (2), and inductor L enters the next energy storage process.

[0082] Preferably, each of the A / B / C three-phase controllers is connected to an information acquisition module, which generates first control information based on the phase information of the input power supply for each phase acquired by the information acquisition module, and provides the first control information to the control center.

[0083] The control center adjusts the first control information based on the overall requirements that the load demands from the power supply circuit output, generates second control information including the switch duty cycle and switching frequency, and transmits the second control information to the corresponding phase switch.

[0084] Specifically, in this embodiment, the three-phase power supply includes three phases: A, B, and C, each of which is connected to a power supply circuit. The connected power supply circuit includes a power supply circuit unit, and each power supply circuit unit includes three circuit groups. The power supply circuit further includes a controller corresponding to each phase, which is connected to an information acquisition module and a control center. The controller is used to generate first control information based on the corresponding phase information of the inputs of each phase of the input power supply acquired by the information acquisition module and to transmit it to the control center. The information acquisition module here may be a sensor, monitor, etc., and is not limited to specific implementation forms and components. It is sufficient that it can acquire voltage / current information of the inputs of each phase of the power supply circuit and the output of the entire power supply circuit in this embodiment.

[0085] The specific method for generating the first control information described herein is not limited. The control center receives the first control information, which includes the phase information of the corresponding phase, transmitted by the controller. Based on the current output voltage and current information of the power supply circuit and the output voltage and current of the entire power supply circuit of the load, acquired by the information acquisition module, the control center generates second control information. The control center then transmits the second control information to the switches in all power supply circuit groups of the corresponding phase, thereby controlling the operating state of the switches. Specifically, the second control information generated by the control center is information on the duty cycle and frequency of the switches. The specific method for generating this information is not limited, and it is sufficient if the technical method of this application can be realized.

[0086] Preferably, the circuit group achieves power factor tracking through the coordinated operation of the inductor and switch, and also achieves dynamic boost and buck adjustment based on input / output voltage and current information, as well as the output voltage required by the connected load.

[0087] Specifically, as shown in Figure 3, the inductors within the circuit group are involved in achieving power factor tracking and dynamically adjusting the voltage boost and buck based on the magnitude of the input voltage and the output voltage requirements of the power supply circuit. The principle of power factor tracking by the coordinated operation of the inductor and switch disclosed in this embodiment is as follows.

[0088] When the input power supply is an AC power supply, the voltage period T' of the input power supply after full-wave rectification is defined as the first time interval [when the input power supply is a DC power supply, the voltage period T' of the input power supply is directly defined as the first time interval without rectification], and within this first time interval T', the input voltage continues to change.

[0089] Because the inductor has the characteristic of not allowing sudden current changes due to its parameter characteristics, the time period interval corresponding to the switching frequency of switch K is defined as the second time period T''.

[0090] When the second time interval T'' is several orders of magnitude smaller than the input power supply voltage period T'', within the range of the voltage period T'', switch K completes hundreds or thousands of on / off cycles, meaning that the input power supply voltage period T'' itself has a trough-to-peak transition process, and because the on / off switching frequency of switch K is high, in the process of controlling the operation of the power supply circuit unit by the operating state of switch K, the input power supply voltage does not change significantly locally and can be considered to have virtually no change, meaning that the corresponding input power supply voltage does not change before and after switching switch K once, and when the first time interval T'' contains a very large number of second time intervals T'', that is, when the input voltage clearly changes, inductor L The inductor L is controlled by switch K and performs multiple charge-discharge processes. In other words, at this time, the inductor L completes multiple cycles of the circuits (1) [input power supply + inductor L + capacitor C + transformer T], (2) [input power supply + inductor L + switch K], and (3) [capacitor C + transformer T + switch K] in the above operating process. The inductor L obtains electrical energy from the voltage (even if low) corresponding to the current input power supply, and smoothly transmits the current to the transformer T through the above circuit, and further supplies it to the electrical energy output terminal. As a result, not only the peak voltage of the sinusoidal voltage of the input power supply but also the very low voltage of the input power supply can be transmitted effectively and smoothly, achieving power factor tracking.

[0091] In this embodiment, the inductor can achieve power factor tracking in the power supply circuit, which means that the inductor can fully utilize the very low voltage electrical energy input by the input power supply, ensuring that the power factor of the power supply circuit can exceed 99%.

[0092] Furthermore, the inductor of the power supply circuit of this application can achieve the above-mentioned power factor tracking and, in combination with the operating state of switch K, realize a dynamic boost and buck operation process based on the specific conditions of the input voltage and the output voltage required for the load of the power supply circuit. The specific boost / buck process and principle are as follows.

[0093] If the voltage supplied by the power supply circuit is insufficient to meet the load requirements and needs to be boosted, the controller controls switch K to increase its duty cycle or decrease its operating frequency, i.e., extend the charging time of inductor L. When the switch is turned off, inductor L can transfer more electrical energy to the primary windings of the capacitors and transformers in the circuit assembly, and further induce it in the secondary windings of the transformers, thereby boosting the voltage. Furthermore, if the voltage supplied by the power supply circuit unit is high and needs to be stepped down, the controller controls switch K to decrease its duty cycle or increase its operating frequency, i.e., shorten the charging time of inductor L. This reduces the electrical energy that inductor L transmits to the capacitors and transformers in the circuit assembly, thereby stepping down the voltage.

[0094] Here, when the entire period interval T'' corresponding to the operating frequency of switch K is higher than the voltage period T' of the input power supply, i.e., T''>>T', the frequency and duty cycle of switch K are adjusted, and further, the charge / discharge time of the main inductor is adjusted to achieve voltage boost / buck. Specifically, the voltage period T' of the input power supply can be set based on the specific conditions of the input power supply. Furthermore, if the input power supply is an AC with periodically changing voltage, for example a sinusoidal AC, the frequency is 100 Hz and the corresponding T' = 10 ms. If the input power supply does not have obvious periodicity in voltage changes, the value of T' can be set by approximating the change period of a sinusoidal AC. The specific setting method should satisfy the requirements described above and realize the means of this application.

[0095] Specifically, as shown in Figure 6, the inductor, in combination with the operating state of the switch in the power supply circuit unit, achieves power factor tracking and voltage boosting and / or bucking in response to output requirements, and the specific operating process is as follows.

[0096] In step S1, the current actual input current, input voltage, output voltage, and output current values ​​are obtained at high frequency.

[0097] In step S2, the acquired current actual output power is compared with the target output power required for the connected load.

[0098] In step S3, based on the comparison result between the current actual output power and the target output power, the peak value of the input current [I_in_peak] is adjusted at a high frequency.

[0099] In step S4, the value of the target input current [I_in_peak] and the current input phase information [current input voltage / peak value of input voltage] are determined at high frequency, and the target input current value [I_target input current value = I_peak value of input current × phase information] is determined.

[0100] In step S5, the current actual input current value is compared with the target input current value, and based on the comparison result, the command information for adjusting the switch duty cycle frequency is determined at a high frequency.

[0101] In step S6, the switches in the power supply circuit execute command information at a high frequency to control the charging and discharging time of the inductor in the power supply circuit, so that the current actual input current value of the power supply circuit becomes as close as possible to the target input current value.

[0102] Specifically, the circuit group in the power supply circuit of this application can achieve both boost / buck conversion and power factor tracking in the case of AC input. In order to ensure that the electrical energy conversion rate of the power supply circuit of this application reaches 98% or more, it is necessary to determine the parameters of the components of the circuit group. When the electrical energy conversion rate is the same, the power supply circuit of this application is less expensive and has superior circuit stability compared to the prior art.

[0103] Specifically, the power supply circuit of this application can perform boost and buck control of output power and voltage based on load requirements, as well as power factor tracking when the input fluctuates periodically. Compared to prior art, when performing the same functions, the power supply circuit of this application has fewer components, simpler connections, lower costs, and superior stability.

[0104] In this embodiment, a three-phase power supply is used in the power supply circuit to perform parallel combining of the output terminals. For each phase, the power factor of that phase is tracked according to the procedure described above, and dynamic voltage boosting and bucking of the output terminals after parallel combining are achieved simultaneously. In the circuit group disclosed in this application, during the switch-off period, the energy stored in the primary windings of the inductor and transformer is induced to the secondary winding by the change in the primary winding current of the transformer. That is, the amount of energy sent to the secondary winding of the transformer depends on the amount of energy stored in the primary windings of the inductor and transformer during the switch-on period. With this configuration, even if the output terminals are directly combined in parallel when operating with a three-phase power supply, no power imbalance occurs among the three parallel-connected three-phase power supply circuit groups.

[0105] In order to ensure the advantages of the power supply circuit of this application, such as high stability and low cost, and to maintain high power conversion efficiency, it is necessary to appropriately determine the parameters of the components included in the circuit group within the power supply circuit.

[0106] The principles for determining component parameters in a circuit group are as follows: The determination of specific component parameters is related to the input voltage, output voltage, and output power of the circuit group. First, the maximum value of the input voltage, the maximum value of the output voltage, and the output power of the circuit group are determined. Here, in the case of AC power, the maximum value of the voltage refers to its RMS value, and in the case of DC power, the maximum value of the voltage refers to the maximum value of the input voltage or output voltage range. Based on the ratio of the maximum value of the input voltage to the maximum value of the output voltage, and the output power of the power supply circuit unit, the parameters of the capacitors, inductors, the inductance of the primary and secondary windings of the transformer, the primary / secondary winding ratio, the operating frequency range of the switches, etc., are determined in the circuit group.

[0107] Specifically, when determining the inductance of the primary and secondary windings of the inductors and transformers in a circuit group, the following points must be considered.

[0108] If parameters such as the operating frequency and duty cycle of the switch, the inductance of the primary winding of the transformer, and the inductance of the inductor remain constant, an increase in input voltage allows the primary winding of the transformer to store more energy during the on-period of the switch. During the off-period of the switch, the energy stored in the primary winding of the transformer is induced in the secondary winding, increasing the output power of the circuit group. Conversely, a decrease in input voltage can reduce the output power of the circuit group.

[0109] Assuming that parameters such as the maximum input voltage, inductor inductance, switch operating frequency, and duty cycle remain constant, reducing the inductance of the transformer's primary winding allows the primary winding to store more energy during the switch's on period. During the switch's off period, the energy stored in the primary winding is induced in the secondary winding, increasing the output power of the circuit group. Conversely, increasing the inductance of the transformer's primary winding can decrease the output power of the circuit group.

[0110] Furthermore, when determining the inductance of the primary winding of a transformer, it is necessary to consider that if the energy stored in the primary winding becomes excessive, the transformer may saturate, potentially reducing the power conversion efficiency.

[0111] In practice, changing the turns ratio of the primary and secondary windings of a transformer affects the conversion efficiency of the circuit. Specifically, given that the input voltage, switch operating frequency and duty cycle, load resistance, transformer primary winding inductance, and inductor inductance are determined, increasing the number of turns of the secondary winding or decreasing the number of turns of the primary winding, i.e., reducing the primary / secondary winding ratio, can increase the output voltage. Conversely, decreasing the number of turns of the secondary winding or increasing the number of turns of the primary winding, i.e., increasing the primary / secondary winding ratio, can decrease the output voltage. By determining the transformer parameters using specific application scenarios and the methods described above, the conversion efficiency of the power supply circuit can be effectively improved.

[0112] In practice, given that the input voltage, switch operating frequency and duty cycle, and transformer primary winding inductance are determined, reducing the inductance of an inductor allows the inductor to store more energy during the switch-on period. During the switch-off period, the energy stored in the inductor charges the transformer's primary winding, and further energy is induced from the primary winding to the secondary winding, increasing the output power of the circuit group. Conversely, increasing the inductance of an inductor can decrease the output power of the circuit group.

[0113] When determining the switching frequency range, under the condition that other component parameters in the circuit group remain constant, reducing the switching frequency increases the energy storage time t during the on-state of the switch within a single period, lowers the frequency f, increases the energy stored in the primary windings of the inductor and transformer during the on-state of the switch, and increases the output power of the circuit group.

[0114] In response to this, increasing the switching frequency reduces the output power of the circuit group. Furthermore, as the switching frequency increases, the switching losses that occur at the on and off moments of the switch increase, and higher frequencies result in greater switching losses.

[0115] Furthermore, the conversion efficiency of the transformer must also be considered, as different magnetic cores have different corresponding inductances and conversion efficiencies at different frequencies. If the frequency is too low, for example below 30 kHz, the transformer may saturate and the conversion efficiency may decrease. On the other hand, if the frequency is too high, for example above 500 kHz, the inductance of the transformer may change significantly and the conversion efficiency may decrease.

[0116] The process for determining the capacitor parameters is as described above. The capacitor stores energy during the switch-off period and resonates with the primary winding of the transformer during the switch-on period, transferring the stored energy to the primary winding of the transformer. If the capacitance value of the capacitor is too small, insufficient energy will be stored in the capacitor during operation, reducing the output power of the power supply circuit unit and decreasing the conversion efficiency. On the other hand, if the capacitance value of the capacitor is too large, when the input voltage is AC, the capacitor voltage will not be able to follow the changes in the input AC voltage, making calculations in the power factor tracking process difficult and reducing the power conversion efficiency.

[0117] Preferably, when the ratio of the maximum input voltage V input to the maximum output voltage V output of the circuit group is V input:V output = 0.2 to 8.0, and the output power is greater than 200W, the parameter range of the capacitor is 30nF to 3μF, the inductance range of the primary winding of the transformer is 10μH to 1000μH, and the ratio range of the primary winding / secondary winding of the transformer is R primary side:R secondary side = 1:5 to 5:1.

[0118] Specifically, when the output power of the circuit group is greater than 200W and the ratio of the maximum input voltage to the maximum output voltage is between 0.2 and 8.0, according to the parameter selection rules above, if the capacitor parameter is less than 30nF, the voltage across the capacitor will rise sharply during the switch's off period, potentially damaging the switch or requiring the use of a switch with a higher voltage rating, thus increasing the cost of the switch. If the capacitor parameter is greater than 3μF, the current in the primary winding inductor of the transformer will rise sharply during the switch's conduction period, and the voltage spike due to the transformer's leakage inductance will be too high at the moment the switch is turned off, potentially damaging the switch or requiring the use of a switch with a higher voltage rating, thereby increasing the cost of the switch. If the inductance of the primary winding of a transformer is less than 10 μH, it is difficult to balance the transformer parameters. For example, if there are too few turns, it is prone to saturation and cannot handle high power. Alternatively, if there are enough turns, but the air gap in the magnetic core is too large, it causes serious magnetic leakage and reduces efficiency. If the primary inductance of the transformer is greater than 1000 μH, the energy stored in the primary inductor of the transformer decreases during the period when the switch conducts and stores energy, requiring the frequency to be reduced in order to handle sufficient power. If the frequency is too low, the conversion efficiency of the transformer is low and it is prone to saturation. If the primary winding / secondary winding ratio of a transformer is less than 1:5, the transformer manufacturing process is difficult, and excessive leakage inductance is likely to occur in the secondary winding. When the switch is conducting, the leakage inductance of the secondary winding causes large fluctuations in the current flowing through the switch, resulting in a significant decrease in efficiency. If the primary winding / secondary winding ratio of a transformer is greater than 5:1, the transformer manufacturing process is difficult, and excessive leakage inductance is likely to occur in the primary winding. The moment the switch is turned off, the leakage inductance of the primary winding causes large voltage fluctuations across the switch, potentially damaging the switch, or requiring the selection of a switch with a higher voltage rating, thus increasing the cost of the switch.

[0119] Specifically, in this embodiment, based on the parameter selection principle described above, the parameters of the inductors in the circuit group are further determined, and since electrical energy is dynamically allocated between the inductor and the primary winding of the transformer based on the relationship between the inductance of the inductor and the inductance of the primary winding of the transformer during the operation of the circuit group, the parameters of the inductors need to be set over a wide range, specifically from 1 μH to 10 mH. If the inductor is involved in the transfer of a large amount of energy, the value of the inductor parameters can be made small, and the parameter range can be set from 1 μH to 100 μH. If the inductor is not involved in energy transfer or is involved in the transfer of a small amount of energy, the value of the inductor parameters can be made large, and the parameter range can be set from 2 mH to 10 mH.

[0120] Furthermore, the following situations must be considered when determining the specific values ​​of the inductor parameters.

[0121] When selecting the inductance of an inductor to a value close to the inductance of the primary winding of a transformer, for example, if both the inductance of the inductor and the inductance of the primary winding of the transformer are designed to be between 10μH and 30μH, during the period when the switch conducts and stores energy, the stored energy of the primary winding of the transformer and the inductor will match. In this way, the inductor shares the role of energy transfer, and there is an advantage in that the inductor and the primary winding of the transformer balance the heat-generating parts. Furthermore, there are requirements for the material of the magnetic core of the inductor, and it is necessary to carefully measure the losses in the energy storage and energy transfer processes of the selected magnetic core to avoid inductor saturation, which can lead to an increase in the cost of the inductor.

[0122] When the inductance of an inductor is much larger than the inductance of the primary winding of a transformer, for example, if the inductor is designed to have an inductance of 800 μH to 1000 μH and the transformer is designed to have an inductance of 10 μH, then during the energy storage period, energy storage by the primary inductor of the transformer becomes the primary energy storage. In this way, energy transfer by the inductor is reduced, which has the advantage of reducing the cost of the inductor's magnetic core.

[0123] If the inductance of the inductor is made much smaller than the inductance of the primary winding of the transformer, for example, if the inductor is designed to have an inductance of 10 μH and the transformer is designed to have an inductance of 1000 μH, then during the energy storage period, the energy stored in the inductor will be much greater than the energy stored on the primary side of the transformer. If both the inductance of the inductor and the inductance of the primary winding of the transformer are made large, for example, if the inductor is designed to have an inductance of 100 μH to 1000 μH and the transformer is designed to have an inductance of 100 μH to 1000 μH, then in order to output more than 200 W of power, the switching frequency must be set to a very low range, which is prone to causing saturation of the transformer and inductor, and the requirements for setting the parameters of the transformer and inductor are very high. In practice, the circuit group of this means has low electrical energy conversion efficiency.

[0124] Specifically, in this embodiment, the operating frequency of the switch is related to various parameters. When parameters such as the inductance of the transformer's primary winding, the inductance of the inductor, the duty cycle of the switch, the input voltage, and the load remain unchanged, lowering the operating frequency of the switch improves the output power of the circuit group, while increasing the operating frequency of the switch lowers the output frequency of the circuit group. Note that if the switching frequency is too low, it is likely to cause saturation of the inductor and transformer, and if the switching frequency is too high, the switch losses increase. Specifically, it is necessary to dynamically adjust the switching frequency in real time based on the fluctuations in the input voltage and the dynamic requirements for the output voltage.

[0125] Furthermore, in the process by which the power supply circuit dynamically adjusts the voltage boost or buck to meet the output requirements, the duty cycle and frequency values ​​of the switch must be calculated and adjusted in real time. The process by which the power supply circuit achieves power factor tracking involves adjusting the duty cycle and frequency of the switch so that the actual input current is synchronized with the input voltage and approaches in real time a target input current that is represented as a regularly changing input voltage. Therefore, the operating frequency of the switch must be dynamically adjusted while satisfying power factor tracking, and specifically, its range is approximately 30K to 500K.

[0126] Based on the above, when the output power of the circuit group is greater than 200W and the ratio of the maximum input voltage to the maximum output voltage is 0.2 to 8, setting the capacitor parameters to 30nF to 3μF, the primary inductance of the transformer to 10μH to 1000μH, the parameter range of the inductor to 1μH to 10mH, and the primary winding / secondary winding ratio of the transformer to 1:5 to 5:1 allows the electrical energy conversion rate of the circuit group to reach 96% or more, and in certain specific scenarios, the electrical energy conversion rate can reach 98%. Specifically, refer to Examples 1 to 64 of the experimental data in Table 1. Compared to the prior art, the electrical energy conversion rate is higher, and the circuit group uses fewer components, achieving an ultra-high electrical energy conversion rate at a low cost, and enabling dynamic boosting and bucking based on load requirements. Compared to the prior art, when the electrical energy conversion rate of the circuit is the same, the power supply circuit unit of this application is more stable, lower in cost, has less electrical energy loss, and is more energy-efficient.

[0127] Preferably, when the ratio of the maximum input voltage to the maximum output voltage of the circuit group is V input:V output = 0.2 to 1.0, and the output power is 200W to 1000W, the range of the inductance of the primary winding of the transformer is 10μH to 1000μH, the range of the capacitor parameters is 100nF to 3μF, and the range of the primary winding / secondary winding ratio of the transformer is R primary side:R secondary side = 1:5 to 1:1.

[0128] Specifically, in this embodiment, the parameter ranges for the corresponding capacitors, primary windings of transformers, and primary / secondary winding ratios of transformers for the components of a circuit group are provided when the output power of the circuit group is 200W to 1000W and the ratio of the calculated input voltage to the calculated output voltage is 0.2 to 1.0. When the specific maximum input voltage, maximum output voltage, and output power are determined according to the above parameter determination principles and processes, by selecting and determining the specific parameters of the corresponding components within the range of corresponding component parameters provided in this embodiment, power factor tracking and dynamic adjustment of boost / buck based on the requirements of the output terminals can be achieved, and the electrical energy conversion rate can reach 98%. For details of experimental data and measurement results of specific parameters, refer to Examples 1 to 18 in Table 1. Compared to the prior art, when the function is the same and the electrical energy conversion rate is the same, the power supply circuit of this application has significantly fewer components than the circuit in the prior art, resulting in less energy loss, lower costs, and higher circuit stability.

[0129] As an example, and not an exhaustive one, if the maximum input voltage of a circuit group is 50V, the maximum output voltage is approximately 250V, and the output power is 200W, then, based on the above parameter design principles, the inductance parameter of the inductor should be designed to approximately 10μH to 1mH, the inductance parameter of the primary winding of the transformer to approximately 10μH to 1mH, the capacitor parameter to approximately 500nF to 3000nF, and the primary winding / secondary winding ratio of the transformer to approximately 1:2 to 1:5. In this case, the corresponding electrical energy conversion rate is 97% or higher.

[0130] Specifically, in this embodiment, the inductance of the primary winding of the transformer is set to 10 μH, or the inductance of the inductor is set to approximately 10 μH, because when the input voltage is 50 V, the amount of energy stored in the inductor and the amount of energy stored on the primary side of the transformer are very low during each energy storage period.

[0131] In order for the primary winding and inductor of a transformer to store sufficient energy during the energy storage period, and for the power supply circuits of multiple circuit groups to supply sufficient power to the output terminals or connected loads, it is necessary to significantly reduce the inductance of the primary winding of the transformer or the inductor.

[0132] However, continuously decreasing the inductance of the primary winding of a transformer or the inductance of an inductor will significantly increase the excitation current of the transformer and drastically reduce its conversion efficiency.

[0133] In this embodiment, the range of the primary winding / secondary winding inductance ratio of the transformer used is approximately 1:5 to 1:2. Since the maximum input voltage is only 50V, if a 1:1 transformer is used, the duty cycle of the switch operation must be increased to improve the output voltage. If the required output voltage is 300V, the duty cycle must be increased to approximately 70% or more to obtain an output voltage of approximately 300V. At this point, the losses in the conduction state of the switch decrease too much, reducing the conversion efficiency of the circuit group. By using a step-up transformer with a primary winding / secondary winding inductance ratio in the range of 1:5 to 1:2, the duty cycle of the switch can be effectively reduced, and the electrical energy conversion efficiency can be improved.

[0134] Due to the low input voltage, the capacitor needs to have a large capacitance to ensure that sufficient energy is stored in the transformer's primary winding during the energy storage period. If the capacitor parameter is 500nF or less, when the output voltage changes dynamically, at some power points, the energy stored in the capacitor becomes insufficient, resulting in reduced efficiency. If the capacitor is 3000nF or more, a large voltage spike occurs when the switch is turned off, requiring a switch with higher voltage resistance, which increases costs.

[0135] When the maximum input voltage is 300V, the maximum output voltage is approximately 300V, and the output power is 1000W, based on the above parameter design principles, the inductance of the primary winding of the transformer is designed to be approximately 60μH to 1mH, the capacitor parameters are set to approximately 100nF to 500nF, and the ratio of the primary winding to the secondary winding of the transformer is approximately 1:1. In this case, the electrical energy conversion rate of the corresponding circuit group is 98% or higher.

[0136] Specifically, and not as an example but as an example, if the embodiment is applicable to the field of solar power generation, with an input of 300V DC voltage, an output of approximately 300V AC voltage at its maximum, a circuit group output power of 1000W, and a maximum input voltage to maximum output voltage ratio of approximately 1:1, then the inductance of the primary windings of the inductor and transformer should be made relatively large, for example, the inductance of the primary winding of the transformer should be 60μH and the inductance of the inductor should be 1mH. Since the ratio of the maximum input voltage to the maximum output voltage is 1, the primary inductance / secondary inductance of the transformer used is approximately 1:1. When the primary / secondary ratio of the transformer is close to 1:1, the transformer manufacturing process is cost-effective and makes it easier to control leakage inductance.

[0137] In the application scenario of this embodiment, if a capacitor of less than 100nF is selected, the capacitor may not be able to supply sufficient energy to the primary winding of the transformer during the period when the switch is on and energy is being stored, potentially reducing the conversion efficiency of the power supply circuit. If a capacitor larger than 500nF is selected, the charging current tends to be large when charging the inductor of the primary winding of the transformer during the period when the switch is on and energy is being stored. At the moment the switch is turned off, a voltage spike occurs due to the primary leakage inductance of the transformer, requiring the selection of a switch with a higher voltage rating, which increases costs.

[0138] In this embodiment, as an example rather than an limitation, if the embodiment is applicable to the field of solar power generation, and the input is a DC voltage of 300V, the output is an AC voltage with a peak value of approximately 300V, the output power of the circuit group is 1000W, and the maximum value of the input voltage and the maximum value of the output voltage are approximately 1:1, then the inductance of the primary windings of the inductor and the transformer is made relatively large. When the inductance is small, the electrical energy conversion efficiency decreases. In practice, by setting the inductance of the primary winding of the transformer to 60μH and the inductance of the inductor to 1mH, the electrical energy conversion efficiency of the power supply circuit can reach 98% or more.

[0139] Then, one can choose to allocate the energy stored during the energy storage period to the transformer and the inductor. By increasing the inductance of the inductor and decreasing the inductance of the transformer, a higher proportion of the energy is stored on the primary side of the transformer and a lower proportion on the inductor during the period when the switch is on and energy is stored. By decreasing the inductance of the inductor and increasing the inductance of the transformer, a lower proportion of the energy is stored on the primary side of the transformer and a higher proportion on the inductor during the period when the switch is on and energy is stored.

[0140] In the application scenario of this embodiment, the capacitor parameters are approximately 100nF to 500nF. In practice, if a capacitor of less than 100nF is selected, there will be insufficient energy in the capacitor during the period when the switch is on and energy is stored, and it will not be able to supply enough energy to the primary winding of the transformer, thus reducing the electrical energy conversion efficiency of the circuit group. If a capacitor of greater than 500nF is selected, there will be too much energy stored in the capacitor during the period when the switch is on and energy is stored, so the charging current tends to be large when charging the primary winding inductor of the transformer. At the moment the switch is turned off, a voltage spike will occur due to the primary leakage inductance of the transformer, requiring the selection of a switch with a higher voltage rating, which increases costs.

[0141] In this embodiment, since the ratio of the maximum input voltage to the maximum output voltage is 1, the primary inductance / secondary inductance of the transformer used is approximately 1:1. When the primary / secondary ratio of the transformer is close, the transformer manufacturing process can reduce costs and easily control leakage inductance.

[0142] Preferably, when the ratio of the maximum input voltage to the maximum output voltage of the circuit group is V input:V output = 0.5 to 1.5, and the output power is 1000W to 2000W, the range of the primary inductance of the transformer is 30μH to 1000μH, the range of the capacitor parameters is 50nF to 3μF, and the range of the primary winding / secondary winding ratio of the transformer is R primary side:R secondary side = 1:2 to 2:1.

[0143] Specifically, in this embodiment, the parameter ranges for the corresponding capacitors, primary windings of transformers, and primary / secondary winding ratios of transformers for the components of a circuit group are provided when the output power of the circuit group is 1000W to 2000W and the ratio of the calculated input voltage to the calculated output voltage is 0.5 to 1.5. When the specific maximum input voltage, maximum output voltage, and output power are determined according to the above parameter determination principles and processes, by selecting and determining the specific parameters of the corresponding components within the range of parameters of the corresponding components provided in this embodiment, power factor tracking and dynamic adjustment of boost / buck based on the requirements of the output terminals can be achieved, and the electrical energy conversion rate can reach 96% or higher, and even 98% or higher. For details of the specific parameter experimental data and measurement results, refer to Examples 32 to 48 in Table 1. Compared to the prior art, when the function is the same and the electrical energy conversion rate is the same, the power supply circuit unit of this application has significantly fewer components than the circuit components of the prior art, resulting in less energy loss, lower costs, and higher circuit stability.

[0144] As an example, and not an limitation, if the input voltage is a sinusoidal voltage of 220V, that is, the maximum input voltage is approximately 311V, the maximum output voltage is approximately 200V, and the output power is 2000W, then, based on the above parameter design principles, if the inductance range of the primary winding of the transformer is set to approximately 30μH to 1mH, the parameter range of the capacitor is approximately 500nF to 3000nF, and the ratio of the primary winding to the secondary winding of the transformer is approximately 2:1, then the electrical energy conversion rate of the power supply circuit unit can reach 97% or more. Compared to conventional technology, for the same electrical energy conversion rate, the power supply circuit unit of this application has fewer components, less energy loss, higher stability, and higher energy efficiency.

[0145] As an example, rather than an limitation, if the input voltage is a sinusoidal voltage of 380V, meaning the maximum input voltage is approximately 540V, the maximum output voltage is approximately 1000V, the ratio of the maximum input voltage to the maximum output voltage is approximately 0.5, and the output power is 1000W, then, based on the aforementioned parameter design principles, the inductance of the primary winding of the transformer should be set to approximately 150μH to 1mH, the capacitor parameters to approximately 50nF to 500nF, and the primary / secondary winding ratio of the transformer to 1:2. In this case, the corresponding electrical energy conversion rate is 98% or higher.

[0146] In this embodiment, if the output voltage is 1000V, the output voltage is too high, and if a 1:1 transformer is used, the output voltage is induced on the primary side of the transformer, and after superimposing with the capacitor voltage, the voltage that the switch must withstand becomes too high, damaging the switch. If a 1:2 transformer is used, during the switch's off period, the 1000V output voltage is induced on the primary side, resulting in a primary voltage of only 500V. After superimposing with the capacitor voltage, the voltage that the switch must withstand during the switch's off period is significantly reduced, widening the range of selectable switches and significantly reducing costs.

[0147] Therefore, the primary / secondary winding ratio of the transformer needs to be 1:2, which significantly reduces the duty cycle of the switch operation and improves the electrical energy conversion efficiency of the circuit group. Furthermore, by converting the 1000V output voltage to the primary side using a transformer with a 1:2 primary-to-secondary ratio, the voltage that the switch transistor must withstand during its off-period can be significantly reduced, broadening the range of selectable switch transistors and drastically reducing costs.

[0148] Preferably, when the ratio of the maximum input voltage to the maximum output voltage of the circuit group is V input:V output = 5.0 to 8.0, and the output power is 1000W to 2000W, the range of the primary inductance of the transformer is 50μH to 250μH, the range of the capacitor parameters is 200nF to 800nF, and the range of the primary winding / secondary winding ratio of the transformer is R primary side:R secondary side = 2:1 to 5:1.

[0149] Specifically, in this embodiment, the parameter ranges for the corresponding capacitors, primary windings of transformers, and primary / secondary winding ratios of transformers for the components of the circuit group are provided when the output power of the circuit group is 1000W to 2000W and the ratio of the calculated input voltage to the calculated output voltage is 5.0 to 8.0. When the specific maximum input voltage, maximum output voltage, and output power are determined according to the above parameter determination principles and processes, by selecting and determining the specific parameters of the corresponding components within the range of corresponding component parameters provided in this embodiment, power factor tracking and dynamic adjustment of boost / buck based on the requirements of the output terminals can be achieved, and the electrical energy conversion rate can reach 96% or higher, and even 98% or higher. For details of the specific parameter experimental data and measurement results, refer to Examples 19 to 31 in Table 1. Compared to the prior art, when the function is the same and the electrical energy conversion rate is the same, the circuit group of this application has significantly fewer components than circuits in the prior art, resulting in less energy loss, lower costs, and higher circuit stability.

[0150] As an example, rather than an limitation, if the input voltage is a sinusoidal voltage of 220V, that is, the maximum input voltage is approximately 311V, the maximum output voltage is approximately 40V, and the output power is 1000W, then, based on the above parameter design principles, the inductance of the primary winding of the transformer should be set to approximately 150μH to 250μH, the capacitor parameter to approximately 200nF to 500nF, and the primary winding / secondary winding ratio of the transformer to be approximately 5:1, in which case the corresponding electrical energy conversion rate should be 96% or higher.

[0151] Specifically, in this embodiment, the output voltage is only 40V, and a switch device may be used instead of a diode in the output half-wave rectifier module. At low voltages, the output current is large, so it is necessary to select a switch component with low internal resistance.

[0152] As an example, and not an limitation, if the input voltage is a sinusoidal voltage of 380V, meaning the maximum input voltage is approximately 540V, the maximum output voltage is approximately 100V, the ratio of the maximum input voltage to the maximum output voltage is approximately 5:1, and the output power is 2000W, then, based on the parameter design principles described above, the inductance of the primary winding of the transformer is set to approximately 50μH to 150μH, the capacitor parameters are set to approximately 400nF to 800nF, and the primary / secondary winding ratio of the transformer is set to approximately 2:1. In this case, the corresponding electrical energy conversion rate is 97% or higher. Compared to prior art, for the same function and electrical energy conversion rate, the circuit group of this application has far fewer components, far lower costs, and higher circuit stability compared to similar products on the market.

[0153] This embodiment describes a case where the input voltage of the circuit group is high, the output voltage is low, and the output current is large. In practice, if a transformer with a primary winding / secondary winding ratio of 1:1 is used, the duty cycle of the switch is too small and the frequency is too low, which can reduce the conversion efficiency of the transformer and further reduce the overall electrical energy conversion efficiency of the circuit group. If a transformer with a primary winding / secondary winding ratio of approximately 2:1 to 3:1 is used, this problem can be effectively solved and the conversion efficiency of the circuit can be improved. However, in this case, the primary leakage inductance of the transformer with a primary winding / secondary winding ratio of 2:1 to 3:1 increases, and if the primary leakage inductance is too large, a voltage spike may occur the moment the switch is turned off, potentially damaging the switch, or it may become necessary to use a switch with a higher voltage rating, which increases costs. Here, in order to reduce the primary and secondary leakage inductance of the transformer, it is recommended to manufacture the transformer using copper foil as the primary and secondary coils and by winding the primary and secondary coils in parallel.

[0154] In this embodiment, the output voltage is only 100V, and it is recommended to use a switch component instead of a diode to perform half-wave output rectification. Furthermore, to reduce conduction losses, it is also possible to configure the switches in the circuit group as switch assemblies formed by connecting multiple switch devices in parallel.

[0155] Preferably, when the ratio of the maximum input voltage to the maximum output voltage of the circuit group is V input:V output = 2.0 to 5.0, and the output power is 2000W to 10000W, the range of the primary inductance of the transformer is 50μH to 250μH, the range of the capacitor parameter values ​​is 200nF to 800nF, and the range of the primary winding / secondary winding ratio of the transformer is R primary side:R secondary side = 1:1 to 2:1.

[0156] Specifically, in this embodiment, the parameter ranges for the corresponding capacitors, primary windings of transformers, and primary / secondary winding ratios of transformers for the components of the circuit group are provided when the output power of the circuit group is 2000W to 10000W and the ratio of the calculated input voltage to the calculated output voltage is 2.0 to 5.0. When the specific maximum input voltage, maximum output voltage, and output power are determined according to the above parameter determination principles and processes, by selecting and determining the specific parameters of the corresponding components within the range of corresponding component parameters provided in this embodiment, power factor tracking and dynamic adjustment of boost / buck based on the requirements of the output terminals can be achieved, and the electrical energy conversion rate can reach 96% or higher, and even 98% or higher. For details of the specific parameter experimental data and measurement results, refer to Examples 49 to 59 in Table 1. Compared to the prior art, when the function is the same and the electrical energy conversion rate is the same, the circuit group of this application has significantly fewer components than circuits in the prior art, resulting in less energy loss, lower costs, and higher circuit stability.

[0157] As an example, rather than an exhaustive one, if the input voltage is 600V to 1000V, the output voltage is 220V to 380V, and the output power is 2000W to 10000W, then, based on the above parameter design principles, the inductance of the primary winding of the transformer should be set to approximately 50μH to 250μH, the capacitor parameter to approximately 100nF to 800nF, and the primary / secondary winding ratio of the transformer to approximately 1:1 to 2:1. In this case, the corresponding electrical energy conversion efficiency will be 96% or higher. If the inductance of the primary winding of the transformer is less than 50μH, the switching frequency of the switch transistor will be too high, making it impossible to use switch transistors such as IGBTs, and furthermore, costs will increase. If it exceeds 250μH, the entire circuit will not be able to output sufficient power, or the switch will need to operate at a very low frequency, reducing the conversion efficiency of the transformer. Compared to conventional technology, the circuit group of this application has far fewer components and costs far less than conventional circuit products, given the same power and efficiency.

[0158] Specifically, as shown in Figures 4 and 5-1, 5-2, 5-3, and 5-4, when the output terminals of three circuit groups connected to a three-phase power supply included in a power supply unit are connected in parallel, the process by which the power supply circuit resolves the ripple problem is as follows:

[0159] As shown in Figure 4, three circuit groups are connected to a three-phase power supply. When the switches of the corresponding circuit groups are ON, the inductors of each circuit group are charged by circuit (2) mentioned above, and the resonant circuit formed by circuit (3) [capacitor C + transformer T + switch K] adjusts the direction of the magnetic field of the primary winding of the transformer. At this time, the circuit groups do not transmit energy to the secondary winding of the transformer. When the switches are turned OFF, the transformer transmits energy to the secondary winding by circuit (1) [input power supply + inductor L + capacitor C + transformer T] mentioned above, charging the output capacitor connected through the output terminal of the circuit group. The output capacitor is then connected to the load, supplying power to the load.

[0160] As mentioned above, when only the output terminal of a single circuit group is connected to an output capacitor, and the output capacitor supplies power to the load, if the input half-wave sinusoidal voltage is zero or low, the output capacitor must supply power to the load using the energy it has stored; otherwise, a large ripple problem will occur. Therefore, to mitigate the ripple, a large-capacity output capacitor is required, which increases costs.

[0161] The three phases of a three-phase power supply have a 120° phase difference. When the resistive loads connected to each phase of the three-phase power supply are the same, the output power remains constant. Three circuit groups are connected to the three-phase power supply simultaneously, and the output terminals of the three circuit groups are connected in parallel. That is, the output terminals of the three circuit groups are simultaneously connected to the positive side of the output capacitor, and the other ends are simultaneously connected to the negative side of the output capacitor. As a result, even if the input voltage of one circuit group in the power supply circuit unit is low, the remaining two circuit groups maintain a constant overall input power supplied from the three-phase power supply to the power supply circuit due to the 120° phase difference, preventing a state of reduced input power. Since the inductor has a power factor tracking function and the output power of the three-phase power supply is constant, the output power of the power supply circuit unit also remains constant, voltage ripple is almost eliminated, and a stable voltage output can be provided to the load.

[0162] Let's take the example of a 380-volt sinusoidal AC power input with an output requirement of 1000 volts / approximately 40 kW. When the input is a single-phase power supply, as shown in Figure 5-1, the single-phase power supply is full-wave rectified to become a half-wave sine wave with a frequency of 100 Hz. As shown in Figure 5-2, when the output capacitor capacitance is 3 mF, the output voltage has a ripple of 100 Hz and an amplitude of approximately 28 volts. On the other hand, when the input is a three-phase power supply, compared to a single-phase power supply, there is a 120° phase difference between the three 380-volt sine waves. As shown in Figures 5-3 and 5-4, when the output terminals of the circuit groups connected to each phase of the three-phase power supply are connected in parallel, a ripple of 300 Hz and an amplitude of approximately 6 volts is generated in the output voltage.

[0163] This significantly reduces ripple, solving problems such as battery overcharging, output overcurrent, and heat generation and reduced lifespan due to frequent charging and discharging of output capacitors. Furthermore, it allows for the selection of output capacitors with smaller parameter values, resulting in cost reduction.

[0164] Preferably, in multiple power supply circuit units, the output terminals of three circuit groups within each power supply circuit unit are connected in parallel, and then the outputs between the multiple power supply circuit units are connected in series, parallel, or a combination of series and parallel.

[0165] Preferably, the output terminals of three circuit groups connected to a three-phase power supply, which are included in a plurality of power supply circuit units, are connected in parallel, and then the outputs between the power supply circuit units are connected in series, parallel, or a combination of series and parallel.

[0166] Specifically, as described above, the ripple problem is solved by connecting the output terminals of each circuit group in parallel after each of the three circuit groups of the power supply circuit unit is connected to the three-phase power supply. When the power supply circuit includes multiple power supply circuit units, the output terminals between the multiple power supply circuit units are connected in series or parallel to supply a wider range of output voltage / power and meet the different voltage requirements of various loads.

[0167] In practice, if a power supply circuit includes multiple power supply circuit units, and each power supply circuit unit includes three circuit groups connected to a three-phase power supply, the output terminals of the three circuit groups within each power supply circuit unit may be connected in series or parallel, and the electrical energy supply output terminals of the multiple power supply circuit units may be connected in series, parallel, or a combination of series and parallel using various switch control devices / modules.

[0168] This document does not limit the specific control devices / modules that connect the output terminals of multiple power supply circuit units in a series / parallel configuration. Any solution for a switch control device / module that connects the output terminals of multiple power supply circuit units in a series / parallel configuration in the prior art or future art is included within the scope of protection of this application, insofar as it is directly applicable to connecting the output terminals of multiple power supply circuit units in a series / parallel configuration as described in this embodiment, or unless it requires modification by a person skilled in the art to be applicable to connecting the output terminals of multiple power supply circuit units in a series / parallel configuration as described in this embodiment, such as relays and electromagnetic switches.

[0169] Preferably, the power supply circuit further includes an input rectifier module that provides a DC input to an inductor in the circuit group, and in multiple power supply circuit units, multiple circuit groups connected to each phase share one full-wave rectifier module.

[0170] Preferably, the output half-wave rectifier module performs half-wave rectification using diodes.

[0171] Specifically, the output half-wave rectifier module provided in this embodiment is connected to one end of the secondary winding of the transformer, and its specific operating principle is as follows.

[0172] After a switch in a circuit group is switched from on to off, the primary windings of the inductor and transformer, which were charged during the on period, discharge, and the capacitor is charged.

[0173] The secondary winding of a transformer obtains electrical energy induced by the current change in the primary winding, and at this time, the current in the secondary winding of the transformer passes through the output half-wave rectifier module to the output capacitor or load in order to supply or store electrical energy.

[0174] After the switch in the circuit group is switched from off to on, the capacitor in the circuit group forms a circuit with the primary winding of the transformer and the switch. Since the capacitor does not allow for sudden voltage changes, it resonates with the primary winding of the transformer. At this time, the direction of the current in the primary winding of the transformer is opposite to the direction of the current during the off period of the switch. Furthermore, since an output half-wave rectifier module is provided on the secondary winding of the transformer, a circuit cannot be formed. Therefore, when the primary winding of the transformer forms a resonant circuit with the capacitor and the switched on, no induced current is generated in the secondary winding of the transformer.

[0175] Thus, the half-wave rectifier module only needs to be able to achieve unidirectional conduction of current in the secondary winding of the transformer. The specific circuit or component that achieves half-wave rectification is not limited. Any circuit solution capable of achieving half-wave rectification in the prior art or future art is included within the scope of protection of this application, insofar as it can be directly applied to the unidirectional conduction of current in the secondary winding of the transformer of this embodiment, or unless it does not require modification by the creative efforts of a person skilled in the art to be applied to the unidirectional conduction of current in the secondary winding of the transformer of this embodiment, for example, a diode / MOS transistor having a unidirectional conduction function, a switch transistor controlled to conduct in one direction, etc.

[0176] Furthermore, by using a diode as an output half-wave rectifier module and connecting it to the corresponding output terminal of the secondary winding of the corresponding transformer, a unidirectional output of the transformer's secondary winding is achieved. Because the diode itself has unidirectional conduction characteristics, achieving half-wave rectification with the diode makes the circuit easier to control and stabilizes its performance.

[0177] Preferably, the output half-wave rectifier module performs half-wave rectification by a first controller that controls a first switch and a first switch transistor. Preferably, the first controller controls the switching mode of the first switch based on the fact that the controller of the power supply circuit unit controls the switch to a mode that induces power to the secondary winding of the transformer.

[0178] Specifically, in this embodiment, the output of the secondary winding of the transformer is half-wave rectified by a switch transistor, and the switch transistor is controlled by a switch transistor controller.

[0179] Furthermore, the operating state of the switch transistor determines whether the secondary winding of the transformer can form a circuit. That is, when the switch transistor is off, a circuit cannot be formed, and when the switch transistor is on, a circuit can be formed. If, after a switch in a circuit group is turned on, the capacitor in the circuit group charges the primary winding of the transformer and the two resonate, the secondary winding of the transformer must not form a circuit; that is, the switch transistor must be turned off at this time. The controller of the switch transistor needs to control the operating state of the switch transistor based on the operating state of the switch in the power supply circuit unit. Based on the above analysis, when a switch in a circuit group is in the ON state, the controller of the switch transistor needs to control the switch to the OFF state. In this embodiment, by providing a controller of the switch transistor and a corresponding switch transistor, the function of half-wave rectifying the output of the secondary winding of the transformer is realized. In certain scenarios, the switch has less energy loss and a higher electrical energy conversion rate than a diode, and is used mainly in low voltage scenarios, such as scenarios below 160 volts.

[0180] Preferably, the switches in the circuit group are implemented by bidirectional switches or controllable switch devices.

[0181] In practice, the selection of switch components is also related to the setting of the switch's operating frequency. For general silicon MOS transistors, it is recommended to limit the maximum frequency to 150K; for silicon carbide MOS transistors, it is recommended to limit the maximum frequency to 250K; for IGBT switch transistors, it is recommended to limit the maximum frequency to 40K; and for gallium nitride MOS transistors, it is recommended to limit the maximum frequency to 500K. The switch in this embodiment is a common 150V high-frequency switch on the market, for example, a high-frequency switch with part number NCEP15T14, and the operating frequency range of the corresponding switch is 50K to 200K.

[0182] Specifically, the switches in the circuit group are responsible for connecting and disconnecting circuits based on the controller's control information. Here, the specific control method by which the controller controls the switches is not limited; that is, the method or path by which the controller provides control signals to the switches is not limited, and it may be wireless or wired.

[0183] Any solution that enables the transmission of control signals from a controller to a switch in the prior art or future technology is included within the scope of this application, insofar as it is directly applicable to the transmission of control signals from the controller of this embodiment to the switch controlled by it, or insofar as it does not require modification by the creative efforts of a person skilled in the art to be applied to this embodiment.

[0184] Furthermore, the specific form of the switch or controller, or both the switch and its controller, that enables the disconnection and connection of circuits in a circuit group is not limited.

[0185] Any switch or controller, or both a switch and a controller, capable of performing circuit interruption and connection in the prior art or future technology, is included within the scope of protection of this application, insofar as it is directly applicable to the circuit interruption and connection functions of the power supply circuit unit of this embodiment, or unless it does not require modification by the creative efforts of a person skilled in the art to be applied to this embodiment.

[0186] Preferably, the leakage inductance range of the transformer in the power supply circuit is less than 1.5%.

[0187] Specifically, during the operation of the power supply circuit unit, when the circuit group is turned on, the input power supply charges the inductor, and at the moment the switch is turned off, the current of the entire circuit changes significantly. At this time, the leakage inductance in the transformer generates a large voltage peak value across the switch, which could potentially destroy the switch. To ensure a high electrical energy conversion rate and higher stability of the power supply circuit, it is optimal to set the range of the transformer's leakage inductance to less than 1.5%.

[0188] Furthermore, this does not limit the specific structure of the transformer that is suitable for the power supply circuit of this application. Any structural solution for a transformer capable of achieving a leakage inductance of less than 1.5% in the prior art or future art is included within the scope of protection of this application, insofar as it is directly applicable to the function of the transformer in the power supply circuit unit of this embodiment, or unless it does not require modification by the creative efforts of a person skilled in the art to be applied to this embodiment.

[0189] Preferably, the transformer in the power circuit has a structure of copper foil or a U-shaped metal plate, and the winding method is parallel winding.

[0190] Specifically, the embodiment discloses the structure and winding method of a transformer in a power supply circuit. A sheet-shaped metal plate or a U-shaped copper plate may be selected as the magnetic core structure of the transformer, and the primary and secondary winding methods of the transformer are parallel windings. In this way, the leakage inductance of the transformer can be reduced and the operating requirements of the power supply circuit can be met.

[0191] As shown in Figure 6, the present application further provides a method for achieving both power factor tracking and dynamic boost / buck adjustment based on output requirements, based on the above power supply circuit, the method being:

[0192] Step S1 involves obtaining the current actual input current, input voltage, output voltage, and output current values ​​at high frequency.

[0193] Step S2 involves comparing the acquired current actual output power with the target output power required for the connected load,

[0194] Step S3 involves adjusting the peak value of the input current [I_in_peak] at a high frequency based on the comparison result between the current actual output power and the target output power.

[0195] Step S4 involves determining the value of the target input current [I_in_peak = I_peak value × phase information] at high frequency based on the peak value of the input current [I_in_peak] and the current input phase information [current input voltage / peak value of input voltage],

[0196] Step S5 involves comparing the current actual input current value with the target input current value, and based on the comparison result, determining the duty cycle frequency adjustment command information for the switch at a high frequency.

[0197] Step S6 includes controlling the charging and discharging time of an inductor in the power supply circuit by having a switch in the power supply circuit execute command information at a high frequency so that the current actual input current value of the power supply circuit is as close as possible to the target input current value.

[0198] Specifically, in step S1 above, when acquiring the current actual input current, input voltage, output voltage, and output current values ​​at a high frequency, it is necessary to acquire the current actual input and actual output of the power supply circuit at a high frequency, and the specific acquisition method is not limited. The data may be acquired by an acquisition unit connected to the controller, or by other methods, and the acquired information is transmitted to the controller and used to determine the command information for adjusting the duty cycle frequency of the switch. For the high frequency, the switching frequency of the power supply circuit can be referenced, for example, it may be equal to the switching frequency or less than the switching frequency, and the high frequency here may be changed according to the actual situation, and is not specifically limited.

[0199] In step S2 above, the acquired current actual output power is compared with the target output power required for the connected load. Once the usage scenario for the connected load or power supply circuit is determined, the corresponding required target output power and target output voltage / current are relatively determined. The current actual output power is then compared with the target output power. If the current actual output power is greater than the target output power, it indicates that the actual output power is higher than the target output power and that the actual output power needs to be reduced. If the actual output power is less than the target output power, it indicates that the actual output does not meet the target output power requirement and that the actual output power needs to be increased.

[0200] In step S3 above, the peak value of the input current [I_in_peak] is determined at high frequency based on the comparison result between the actual output power and the target output power. If the actual output power is less than the target output power, the peak value of the input current is increased to improve the current actual output voltage or current, and further improve the actual output power to meet the load requirements. If the actual output power is greater than the target output power, the peak value of the input current is decreased to decrease the current actual output voltage or current, and further decrease the output power to meet the load requirements. The amount of increase or decrease in the peak value of the input current must take into account the difference between the actual output power and the target output power. For example, if the difference between the two exceeds a predetermined value, the amount of increase in the peak value of the input current is increased to quickly meet the load requirements. Determining the peak value of the input current is a process that is determined and adjusted at high frequency, and the method of determining the increase / decrease amount is not limited as long as it meets the load's requirements for the target output.

[0201] In step S4 above, the value of the target input current [I_in_peak] and the current input phase information [current input voltage / peak value of input voltage] are determined at high frequency. The current input phase information is the ratio of the current actual input voltage supplied from the current input power supply to the power supply circuit to the peak value of the periodically fluctuating voltage supplied from the input power supply to the power supply circuit. The value of the target input current is the product of the peak value of the input current determined in step S3 and the phase information, i.e., I_in_peak × V_current actual input voltage / V_peak value of input voltage.

[0202] In step S5 above, the current actual input current value is compared with the target input current value, and based on the comparison result, the command information for adjusting the switch duty cycle and frequency is determined at high frequency. Specifically, if the current actual input current value is smaller than the target input current value, the controller generates command information to control the switch to decrease the frequency and increase the duty cycle, thereby controlling the operating state of the switch and further controlling the charging time of the inductor, thereby increasing the input current to satisfy the power factor tracking requirement and achieving output control by bringing the current actual input current closer to the target input current value. Otherwise, if the current actual input current value is larger than the target input current value, the controller generates command information to control the switch to increase the frequency and decrease the duty cycle, thereby controlling the operating state of the switch and further controlling the charging time of the inductor, thereby reducing the input current to satisfy the power factor tracking requirement and achieving output control by bringing the current actual input current closer to the target input current value. Specifically, the degree of decrease or increase in the switch duty cycle and the magnitude of the increase or decrease in switching frequency must be determined based on the difference between the current actual input current value and the target input current value, without limiting the specific implementation method and process. Those skilled in the art can set these according to their actual scenarios. Furthermore, the target input current value here includes the phase information of the current input voltage; that is, when adjusting the current actual input current value based on the target input current value, the phase information of the current input power supply is taken into consideration. This ensures that the current actual input current value is always close to the target input current value and fluctuates around the target input current value, thereby providing the power supply circuit with PFC (power factor tracking) capability.

[0203] In step S6 above, the switches of the power supply circuit execute command information at a high frequency to control the charging and discharging time of the inductor in the power supply circuit so that the current actual input current value of the power supply circuit is as close as possible to the target input current value. Specifically, the switches of the power supply circuit execute commands transmitted by the controller to adjust the current duty cycle or frequency at a high frequency to control the charging and discharging time of the inductor in the power supply circuit so that the current actual input current value of the power supply circuit is as close as possible to the target input current value, thereby achieving power factor tracking and output power control, i.e., dynamic adjustment of boost and buck based on output demands.

[0204] The power supply circuit of this application can simultaneously achieve power factor tracking and boost / buck control of the output voltage, has a small number of components, simple connections, excellent circuit stability, low cost, and high energy efficiency.

[0205] The technical features of the embodiments described above can be combined in any way, and for the sake of brevity, not all possible combinations of the technical features in the embodiments described above will be explained. However, as long as there is no contradiction in these combinations of technical features, they should all fall within the scope described herein.

[0206] The embodiments described above illustrate only a few embodiments of this application, and while their descriptions are specific and detailed, this should not be understood as limiting the scope of the claims of the present invention. Furthermore, those skilled in the art can make several modifications and improvements without departing from the concept of this application, and all of these fall within the scope of protection of this application. Therefore, the scope of protection of this patent application should be based on the attached claims. TIFF2026521146000002.tif244161TIFF2026521146000003.tif244161

Claims

1. A power supply circuit based on a three-phase power supply, The power supply circuit includes an information acquisition module and a power supply circuit unit. The power supply circuit unit includes three circuit groups formed by three phases, A-phase, B-phase, and C-phase, connected to a three-phase power supply, and a control center for controlling the operating state of the three circuit groups. The circuit group includes an input rectifier module, an inductor, a capacitor, a switch and its controller, a transformer, and an output half-wave rectifier module. One end of the inductor is connected to the terminal of one phase of the three-phase power supply, and the other end of the inductor is connected to one end of the switch and one end of the capacitor. The other end of the capacitor is connected to one end of the primary winding of the transformer, and the other end of the primary winding of the transformer and the other end of the switch are connected to the fire terminal or neutral terminal of the other phase. The two output terminals of the secondary winding of the transformer are output terminals for supplying power to the circuit group, and the terminal corresponding to one end of the capacitor connected to the primary winding is connected to the output half-wave rectifier module. A power supply circuit characterized in that the output terminals of three circuit groups connected to a three-phase power supply, included in the power supply circuit unit, are connected in parallel.

2. The control center controls the duty cycle and switching frequency of the switches in the circuit group by transmitting control information to the switches. When a switch in a corresponding circuit group is in the ON state, the switch in that circuit group forms a circuit with the connected input power supply for that phase and an inductor, and charges the inductor. The capacitor, together with the switch and the primary winding of the transformer, forms an LC oscillation circuit, and the energy stored in the capacitor moves between the primary winding of the transformer and the capacitor. A power supply circuit based on a three-phase power supply according to claim 1, characterized in that when the switch is in the off state, the connected input power supply of the relevant phase, the inductor, the capacitor, and the primary winding of the transformer form an LLC oscillation circuit, the connected input power supply of the relevant phase and the charged inductor charge the capacitor, and the charged inductor superimposes its own energy on the energy stored on the primary side of the transformer, thereby inducing power to the secondary winding due to the change in the primary current of the transformer.

3. A power supply circuit based on a three-phase power supply according to claim 1, characterized in that each A-phase / B-phase / C-phase controller connected to the information acquisition module generates first control information based on the phase information of the corresponding phase of the input power supply collected by the information acquisition module, provides the first control information to the control center, the control center adjusts the first control information based on the overall power supply circuit output requirements of the load, generates second control information including the duty cycle and switching frequency of the switches, and provides the second control information to the switches of the corresponding phases.

4. The power supply circuit based on a three-phase power supply according to claim 1, characterized in that the circuit group achieves power factor tracking through the coordinated operation of an inductor and a switch, and achieves dynamic adjustment of boost and buck based on input voltage, output voltage, current information, and output voltage requirements from the connected load.

5. A power supply circuit based on a three-phase power supply according to claim 1, characterized in that the ratio of the maximum input voltage V-in to the maximum output voltage V-out of the circuit group is V-input:V-output = 0.2 to 8, the parameter range of the capacitor is 30nF to 3μF when the output power is greater than 200W, the inductance range of the primary winding of the transformer is 10μH to 1000μH, and the ratio range of the primary winding / secondary winding of the transformer is R-primary side:R-secondary side = 1:5 to 5:

1.

6. The power supply circuit based on a three-phase power supply according to claim 1, characterized in that the parallel connection of the output terminals of three circuit groups connected to a three-phase power supply, which are included in the power supply circuit unit, includes a configuration in which the output terminals of the three circuit groups connected to the three-phase power supply are connected in parallel and then connected to an output capacitor, or a configuration in which the output terminals of the three circuit groups are each connected to an output capacitor and then the output capacitors are connected in parallel.

7. The output half-wave rectifier module is characterized by performing half-wave rectification using a diode, and is a power supply circuit based on a three-phase power supply according to any one of claims 1 to 6.

8. The power supply circuit based on a three-phase power supply according to any one of claims 1 to 6, characterized in that the output half-wave rectifier module is half-wave rectified by a first switch and a first controller that controls the first switch.

9. The power supply circuit based on a three-phase power supply according to claim 8, characterized in that the first controller controls the switching mode of the first switch based on the operating mode of the circuit group controller for controlling the switch to induce power in the secondary winding of the transformer.

10. A power supply circuit based on a three-phase power supply according to any one of claims 1 to 6 and 9, characterized in that the switches of the circuit groups in the power supply circuit are implemented by bidirectional switches or controllable switch devices.

11. A power supply circuit based on a three-phase power supply according to any one of claims 1 to 6 and 9, characterized in that the range of leakage inductance of the transformers in the circuit group in the power supply circuit is less than 1.5%.

12. The power supply circuit based on a three-phase power supply according to any one of claims 1 to 6 and 9, characterized in that the transformer in the circuit group of the power supply circuit has a structure of copper foil or a U-shaped metal piece and the winding method is parallel winding.

13. A method for simultaneously achieving power factor tracking and dynamic boost / buck adjustment using a power supply circuit based on a three-phase power supply as described in any one of claims 1 to 12, Step S1 involves obtaining the current actual input current, input voltage, output voltage, and output current values ​​at a high frequency. Step S2 involves comparing the acquired current actual output power with the target output power required for the connected load, Step S3 involves adjusting the peak value of the input current at a high frequency based on the comparison result between the current actual output power and the target output power. Step S4 involves determining the value of the target input current at a high frequency based on the peak value of the input current and the phase information of the current input. Step S5 involves comparing the current actual input current value with the target input current value, and determining the duty cycle frequency adjustment command information for the switch at a high frequency based on the comparison result. A method characterized by including step S6, in which a switch in the power supply circuit executes the command information at a high frequency and controls the charging and discharging time of an inductor in the power supply circuit so that the current actual input current value of the power supply circuit becomes as close as possible to the target input current value.

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