Power supply circuit based on three-phase power and method for realizing PFC (Power Factor Correction) / boost / buck

Abstract

The invention discloses a power supply circuit based on three-phase power and a method for simultaneously realizing power factor tracking / dynamic step-up / step-down, and the circuit comprises an information acquisition module and a power supply circuit unit, the power supply circuit unit comprises three circuit groups formed by connecting three phases of three-phase power and a control center used for controlling the working states of the three circuit groups; each circuit group comprises an input rectification module, an inductor, a capacitor, a switch, a controller of the switch and a transformer, and the output ends of the three circuit groups included in the power supply circuit unit are connected in parallel or in series, so that the ripple problem is solved, and meanwhile, the electric energy conversion rate is improved; the power supply circuit can adjust the peak value of input current through high frequency, further adjust the frequency and duty ratio of a switch and control the charging and discharging time of an inductor, power factor tracking is achieved, meanwhile, dynamic adjustment of boost and buck is achieved, the load requirement is met, cost can be effectively saved, energy loss is low, and the electric energy conversion rate reaches up to 96% or above.

Description

Technical Field

[0001] The present invention relates to the field of power supply technology, and in particular to a power supply circuit technology in a high-power scenario. Background Art

[0002] In the prior art, the power supply module used in relatively high power (generally greater than 200 watts is considered relatively high power) or high power scenarios includes two-stage circuits, the front stage generally adopts various topological circuits based on Boost rectifier or equivalent to Boost circuit to realize power factor tracking (also known as PFC). The mainstream PFC topology scheme is three-phase three-wire three-level VIENNA (for example, it also includes: two-way staggered parallel three-phase three-wire three-level VIENNA, single-phase staggered three-phase three-wire three-level VIENNA), totem pole topology circuit, Boost circuit (for example, it also includes: staggered Boost circuit suitable for single-phase electricity); the rear-stage DC-DC scheme generally realizes voltage reduction / voltage regulation through a circuit topology based on a full bridge (for example: two groups of staggered series two-level full-bridge LLC, two groups of staggered parallel two-level full-bridge LLC, three-level phase-shifted full-bridge, two groups of two-level LLC full-bridge series, two groups of two-level three-phase staggered LLC series, three-level LLC half / full bridge, etc.).

[0003] It can be seen that the power module of the prior art requires two-stage circuits to realize power conversion and transmission. It has many components and complex circuit connections. It has problems such as high cost, large energy loss, poor stability, low conversion rate, and poor scalability. At the same time, it is also necessary to solve the ripple problem by increasing the capacitance of the output capacitor. Summary of the invention

[0004] One purpose of the present application is to provide a power supply circuit based on three-phase electricity and a method for the power supply circuit to achieve power factor tracking and boost / step-down, so as to solve the problems of complex connection of power supply circuit components, low power conversion rate and weak scalability in the prior art, and at the same time solve the problem of relatively large industrial frequency ripple caused by a single-stage circuit.

[0005] The present application provides a power supply circuit based on three-phase electricity, the power supply circuit includes an information acquisition module, a power supply circuit unit, the power supply circuit unit includes three circuit groups formed by three phases of A / B / C phases connected to the three-phase electricity and a control center for controlling the working states of the three circuit groups;

[0006] The circuit group includes an input rectifier module, an inductor, a capacitor, a switch and a controller thereof, and a transformer; one end of the inductor is used to connect to the live wire end of one phase of three-phase electricity, 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 live wire end or the neutral wire end of another phase, and the two output ends of the secondary winding of the transformer are output ends for providing electric energy for the circuit group, wherein the end corresponding to one end of the capacitor connected to the primary winding needs to be connected to an output half-wave rectifier module for performing half-wave rectification on the output of the circuit group;

[0007] Wherein, the power supply circuit unit includes three circuit groups whose output ends corresponding to the three-phase electricity are connected in parallel;

[0008] The maximum input voltage V 入 With the maximum output voltage V 出 The ratio is V 入 :V 出 =0.3-7.6, when the output power is greater than 200W, the parameter range of the capacitor is 35nF-2.9μF, the inductance range of the primary winding of the transformer is 15μH-950μH; the ratio range of the primary winding / secondary winding of the transformer is R 原 : R 副 =1∶5-5∶1.

[0009] Preferably, the control center controls the duty cycle and frequency of the switches in the circuit group by transmitting control information to the switches;

[0010] When the switch in the corresponding circuit group is in a closed state, the switch in the corresponding circuit group forms a loop with the input power supply of the phase connected and the inductor, and charges the inductor; the capacitor forms an LC oscillation loop with the switch and the inductor of the primary winding of the transformer, and the energy stored in the capacitor is transferred between the primary winding of the transformer and the capacitor;

[0011] When the switch is in the off state, an LLC oscillation circuit is formed with the connected input power supply of this phase, the inductor, the capacitor and the primary winding of the transformer. The connected input power supply of this phase and the charged inductor charge the capacitor. At the same time, the charged inductor superimposes its own energy on the energy stored in the primary side of the transformer and induces electrical energy into the secondary winding through the current change of the primary side of the transformer.

[0012] Preferably, the A / B / C three-phase controller is connected to the information acquisition module, and is used to generate first control information according to the phase information of the corresponding phase of the input power supply collected by the information acquisition module, and provide the first control information to the control center; the control center adjusts the first control information according to the overall requirements of the load for the power circuit output, and generates second control information including the switch duty cycle and frequency; and provides the second control information to the switch of the corresponding phase.

[0013] Preferably, the circuit group realizes power factor tracking through inductance and switch cooperation, and also realizes dynamic adjustment of voltage boost and voltage reduction according to input / output voltage, current information and the requirements of the connected load for the output voltage.

[0014] Preferably, the power supply circuit unit includes three circuit groups corresponding to three-phase electricity connected in parallel, including: connecting the output ends of the three circuit groups corresponding to the three-phase electricity in parallel and then connecting the output capacitors, or connecting the output ends of the three circuit groups to the output capacitors respectively and then connecting the output capacitors in parallel.

[0015] Preferably, the half-wave rectification module realizes half-wave rectification through a diode.

[0016] Preferably, the half-wave rectifier module realizes half-wave rectification through a first switch and a first controller controlling the first switch.

[0017] Preferably, the first controller controls the switching mode of the first switch according to the mode in which the controller of the circuit group controls the switch to sense the electrical energy of the secondary winding of the transformer.

[0018] Preferably, the switching of the circuit group of the power supply circuit is realized by a bidirectional switch or a controllable switching device.

[0019] Preferably, the transformer leakage inductance value range of the circuit group in the power supply circuit is less than 1.5%.

[0020] Preferably, the transformer structure of the circuit group in the power supply circuit is copper foil or U-shaped metal sheet, and the winding method is parallel winding.

[0021] The present application also provides a method for dynamically adjusting power factor tracking and voltage boost / voltage reduction based on the above-mentioned three-phase power supply circuit, the method comprising:

[0022] Step S1, obtaining the current actual input current, input voltage, output voltage, and output current values ​​at high frequency;

[0023] Step S2, comparing the current actual output power obtained with the target output power required by the connected load;

[0024] Step S3, according to the comparison result between the current actual output power and the target output power, adjusting the input current peak value at high frequency:

[0025] Step S4, determining the target input current value at high frequency according to the input current peak value and the current input phase information;

[0026] Step S5, comparing the current actual input current value with the target input current value, and determining the duty cycle and frequency adjustment instruction information of the switch at high frequency according to the comparison result;

[0027] Step S6, the switch of the power circuit executes the instruction information at a high frequency to control the charging and discharging time of the inductor in the power circuit so that the current actual input current value of the power circuit is as close as possible to the target input current value.

[0028] Compared with the prior art, the power supply circuit based on three-phase electricity of the present 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 electricity and a control center for controlling the working status of the three circuit groups; the circuit group includes an input rectifier module, an inductor, a capacitor, a switch and its controller, and a transformer; the present application uses a single-stage circuit to achieve the capabilities of the traditional technology PFC+DC-DC, including rectification, power factor tracking, dynamic boost, buck, high-frequency isolation and other functions, which saves a lot of components and improves the power conversion efficiency; the maximum input voltage V of the circuit group is 入 With the maximum output voltage V 出 The ratio is V 入 :V 出 =0.3-7.6, when the output power is greater than 200W, the parameter range of the capacitor is 35nF-2.9μF, the inductance range of the primary winding of the transformer is 15μH-950μH; the ratio range of the primary winding / secondary winding of the transformer is R 原 : R 副 =1:5-5:1, which can make the power conversion rate of the power supply circuit more than 96%. Due to the working principle of the circuit group included in this application, the output end is supported to be synthesized in parallel between the circuit groups. This application uses a power supply circuit based on three-phase electricity, and after tracking the power factor of each phase of the three-phase electricity separately, the output end of the three-phase electricity is connected in parallel for synthesis, which solves the problem of large power frequency ripple caused by a single-stage circuit. Moreover, it will not cause the problem of inconsistent power between multiple circuit groups after parallel synthesis. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A connection diagram of a circuit group included in a power circuit unit in an embodiment of the present application;

[0030] Figure 2This is a connection diagram of a power supply circuit based on three-phase electricity in one embodiment of the present application;

[0031] Figure 3-1 The waveform diagram of the input inductance of the power circuit corresponding to the input power supply being a single-phase sine wave;

[0032] Figure 3-2 The ripple waveform of the output voltage corresponding to the input 3-1;

[0033] Figure 3-3 The waveform diagram of the input inductance of the power circuit corresponding to the input power supply being a three-phase electric sine wave;

[0034] Figure 3-4 The ripple waveform of the output voltage corresponding to the input 3-3 and Figure 3-2 Schematic diagram of comparison of output voltage ripple waveform;

[0035] Figure 4 This is a flow chart of a method for a power supply circuit to simultaneously implement PFC and voltage boost / voltage reduction in another embodiment of the present application. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0037] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] The present application provides a power supply circuit based on three-phase electricity to solve the problems of high cost, weak stability, large energy loss, low conversion rate, weak scalability and output ripple caused by the large number of components and complex connections in the power supply circuit of the prior art.

[0039] In the prior art, the power supply circuit is configured with a front / rear two-stage circuit, in which the front-stage circuit completes power factor tracking and the rear-stage circuit completes voltage reduction / stabilization. The power supply circuit based on three-phase electricity disclosed in this embodiment includes at least one power supply circuit unit, and the power supply circuit unit includes an inductor, a switch and its controller, a capacitor and a transformer. By configuring three circuit groups connected to three-phase electricity in each power supply circuit unit, the output ends of the three circuit groups are connected in parallel to effectively solve the ripple problem. The power supply circuit of the present application may also include multiple power supply circuit units. In this case, the output ends of the multiple power supply circuit units may be combined in series and parallel to achieve output of a wide range of voltage / power.

[0040] The present application provides a power supply circuit based on three-phase electricity to solve the problems of high cost, weak stability, large energy loss, low conversion rate and ripple caused by the large number of components and complex connections in the power supply circuit of the prior art.

[0041] Ginseng Figure 1 , Figure 2 As shown, the present application provides a power supply circuit based on three-phase electricity, the power supply circuit includes an information acquisition module, a power supply circuit unit, the power supply circuit unit includes three circuit groups formed by three phases of A / B / C phases connected to the three-phase electricity and a control center for controlling the working status of the three circuit groups;

[0042] The circuit group includes an input rectifier module, an inductor, a capacitor, a switch and a controller thereof, and a transformer; one end of the inductor is used to connect to the live wire end of one phase of three-phase electricity, 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 live wire end or the neutral wire end of another phase, and the two output ends of the secondary winding of the transformer are output ends for providing electric energy for the circuit group, wherein the end corresponding to one end of the capacitor connected to the primary winding needs to be connected to an output half-wave rectifier module for performing half-wave rectification on the output of the circuit group;

[0043] The power supply circuit unit includes three circuit groups whose output ends corresponding to the three-phase electricity are connected in parallel.

[0044] Specifically, in this embodiment, the power supply circuit includes a power supply circuit unit which is three circuit groups, wherein each circuit group is connected to each phase of the three-phase electricity. The power supply circuit may include multiple power supply circuit units, that is, each phase of the three-phase electricity can be connected to multiple circuit groups, and the working modes or working states of the multiple power supply circuit units are consistent, that is, the logic of the controller controlling and adjusting the duty cycle and frequency of the switch in the working group of each power supply circuit unit is the same.

[0045] Ginseng Figure 1 , Figure 2 As shown, the circuit group includes an input rectifier module, an inductor, a capacitor, a switch and its controller, and a transformer; one end of the inductor is used to connect to the positive output terminal of a power supply after rectification of one phase of three-phase electricity, 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 output terminal of the rectified three-phase electricity, the two output ends of the secondary winding of the transformer are the output ends that provide electric energy for the circuit group, wherein the end corresponding to one end of the capacitor connected to the primary winding is connected to an output half-wave rectifier module used for half-wave rectification of the secondary output of the transformer.

[0046] Specifically, each power circuit unit includes three circuit groups, each circuit group is connected to each phase of the three-phase power, and there are two specific ways to connect to each phase. Figure 2 As shown in the figure, one is that the three circuit groups of the power circuit unit are respectively connected to the AB phase, BC phase and AC phase of the ABC three-phase electricity. At this time, the effective value of the input voltage provided by the three-phase electricity to the power circuit is 380 volts; as shown in Figure 3, the other is that the three circuit groups of the power circuit unit are respectively connected to the A phase and the neutral line, i.e. AN, the B phase and the neutral line, i.e. BN, the C phase and the neutral line, i.e. CN, of the ABC three-phase electricity. At this time, the effective value of the input voltage provided by the three-phase electricity to the power circuit is 220 volts.

[0047] The power supply circuit unit includes three circuit groups whose output ends corresponding to the three-phase electricity are connected in parallel.

[0048] Preferably, the power supply circuit unit includes three circuit groups corresponding to three-phase electricity connected in parallel and then connected to capacitors.

[0049] Specifically, each circuit group of the power supply circuit unit is connected to a single-phase or one-phase of three-phase input, which is a sinusoidal AC. After rectification by a full-bridge rectifier module, it is converted into a steamed wave input to the inductance of the circuit group. Because the inductance of the circuit group has a power factor tracking function (see the following introduction to the power factor tracking process for details), the output voltage of the circuit group at this time is a 100HZ fluctuation superimposed on the DC corresponding to the input. The 100HZ fluctuation is caused by the input steamed wave, and the input power varies with the phase of the steamed wave. When the input voltage is zero, the output of the output secondary winding of the circuit group is also zero. At this time, the output of the circuit group is completely provided by the output capacitor (for example, a filter / electrolytic capacitor) connected to the output end of the circuit group. At this time, the output capacitor voltage connected to the output end of the circuit group will drop, thereby causing the voltage provided by the circuit group to the load, that is, the capacitor voltage, to drop, that is, an obvious ripple problem will occur.

[0050] The three circuit groups are connected to three-phase electricity at the same time. The three phases of the three-phase electricity have a phase difference of 120°. Figure 2 As shown, the output ends of the three circuit groups included in the power circuit unit are respectively connected to the three output capacitors C1, C2 and C3, the positive poles of the three capacitors are connected together as the output end of the power circuit unit, and the negative poles are connected together as the other output end of the power circuit unit, that is, the three circuit groups charge the three output capacitors connected in parallel at the same time, and the output capacitors C1, C2 and C3 are connected in parallel and then connected to the load to provide electrical energy for the load, which can effectively solve the ripple problem. It is also possible to directly connect the output ends of the three circuit groups of the power circuit unit in parallel, and connect one or a group of output capacitors at the same time, and the output capacitors are then connected to the load to provide electrical energy for the load, which also solves the ripple problem; wherein, the output capacitor can be any one of an electrolytic capacitor, a film capacitor, etc., and its specific form is not limited, as long as it can achieve energy storage and meet the circuit group to provide output to the load.

[0051] In this embodiment, the circuit group of the present application can directly connect and synthesize the output ends of multiple circuit groups because of its fewer components and strong circuit stability. The power factor tracking and dynamic voltage step-up and voltage step-down methods disclosed in the present application are used to control the switch of each circuit group, so that the current can be equalized between the circuit groups with multiple output ends connected in parallel, that is, there will be no huge power difference between the multiple circuit groups, which will damage the equipment.

[0052] In practice, the present application provides a method of directly tracking the power factor of the three-phase electricity separately, and connecting the output ends after dynamic voltage boost and voltage reduction in parallel, thereby ensuring the power conversion rate of the power supply circuit and significantly solving the ripple problem.

[0053] In one of the preferred embodiments, the control center controls the duty cycle and frequency of the switches in the circuit group by transmitting control information to the switches;

[0054] When the switch in the corresponding circuit group is in a closed state, the switch in the corresponding circuit group forms a loop with the input power supply of the phase connected and the inductor, and charges the inductor; the capacitor forms an LC oscillation loop with the switch and the inductor of the primary winding of the transformer, and the energy stored in the capacitor is transferred between the primary winding of the transformer and the capacitor;

[0055] When the switch is in the off state, an LLC oscillation circuit is formed with the connected input power supply of this phase, the inductor, the capacitor and the primary winding of the transformer. The connected input power supply of this phase and the charged inductor charge the capacitor. At the same time, the charged inductor superimposes its own energy on the energy stored in the primary side of the transformer and induces electrical energy into the secondary winding through the current change of the primary side of the transformer.

[0056] Specifically, refer to Figure 1 , 2As shown, the working principle and process of a circuit group in a power circuit unit connected to three-phase electricity are as follows:

[0057] The control center transmits control information including duty cycle and frequency to the switch, and controls the time ratio of the switch in the circuit group to be closed within the cycle time; when the switch in the corresponding circuit group is in a closed state, the switch in the corresponding circuit group forms a loop with the connected power supply and inductor of the phase, and charges the inductor; the capacitor forms an LC oscillation loop with the switch and the inductor of the primary winding of the transformer; when the switch is in an open state, an LLC oscillation loop is formed with the connected power supply, inductor, capacitor and primary winding of the transformer, and the connected input power supply of the phase and the charged inductor charge the capacitor, and at the same time, the charged inductor superimposes its own energy on the energy stored in the primary side of the transformer, and senses the electric energy into the secondary winding through the current change of the primary side of the transformer.

[0058] Specifically, refer to Figure 1 , 2 As shown, the control center controls the frequency and duty cycle of the opening and closing of the switches of each circuit group in the three circuit groups according to the power supply circuit unit's demand for the power output end. Figure 1 As shown, when the switch K of the circuit group is in a closed state, the switch K forms a loop with the input power supply and the inductor L, and the input power supply charges the inductor L through the loop; the capacitor C of the circuit group forms an LC oscillation loop with the switch K and the inductor of the primary winding of the transformer T; when the switch K is in an open state, the input power supply, the inductor L, the capacitor C and the inductor of the primary winding of the transformer T form an LLC oscillation loop, and the connected input power supply of the phase and the charged inductor L charge the capacitor C, and at the same time, the charged inductor superimposes its own energy on the energy stored in the primary side of the transformer T, and induces the electric energy into the secondary winding through the current change of the primary side of the transformer.

[0059] The circuit group disclosed in this embodiment controls the working state of the switch K so that the inductor L is charged and then discharged to the capacitor C and the primary winding of the transformer T, so that the primary winding of the transformer T obtains energy and senses it to the secondary winding of the transformer T, and further outputs the electric energy. By controlling the frequency and duty cycle of the switch K, the charge / discharge time of the inductor L and the charge / discharge time of the primary winding inductance of the transformer are controlled, and the amount of electric energy output by the secondary winding of the transformer is further controlled. Compared with the prior art, this embodiment can realize the transmission of electric energy through a power supply circuit including very few components, with low cost, strong stability, and high conversion rate.

[0060] Specifically, continue to Figure 1As shown, the detailed working process of the circuit group of the power circuit unit disclosed in this embodiment is as follows: when the switch K is closed, the input power charges the inductor L, and the inductor L stores energy. At the moment when the switch K is disconnected, the inductor L will generate a high voltage to keep the current at both ends from changing suddenly, and the electric energy is transmitted through the new loop ① [input power + inductor L + capacitor C + transformer T] formed after the switch K is disconnected. The input power is discharged, the inductor L and the primary winding of the transformer T are discharged, the capacitor C is charged, and the current change of the primary winding of the transformer T is sensed to the secondary winding of the transformer T. At this time, the voltage of the input power plus the voltage of the inductor L is equal to the voltage of the capacitor C plus the voltage of the primary winding of the transformer T, that is: V 输入电源 +V L =V C +V T原 ; Transformer T senses electric energy to its secondary winding, and the secondary winding is output to the power supply output end of the power circuit unit through a half-wave rectifier module to provide electric energy to the load; when switch K changes from an open state to a closed state, the circuits and specific working processes formed by the power circuit unit are as follows: the power circuit charges the inductor L through circuit ② [input power supply + inductor L + switch K], and charges the capacitor C and the primary winding of the transformer T through circuit ① [input power supply + inductor L + capacitor C + transformer T]. After the charging of capacitor C is completed, capacitor C charges the primary winding of transformer T through circuit ③ [capacitor C + transformer T + switch K] to keep the voltage at both ends of the capacitor C from changing suddenly. Because a half-wave rectifier module is set in the circuit of the secondary winding of transformer T, transformer T cannot transfer electric energy to the secondary winding of transformer T at this time. At this time, it is equivalent to that the primary winding of transformer T and capacitor C form an LC resonant circuit to maintain the electric energy of the circuit; at the same time, after switch K is in a closed state, the input power is charged to the inductor L through the second circuit, and the inductor L performs the next energy storage.

[0061] In one of the preferred embodiments, the A / B / C three-phase controller is connected to the information acquisition module, and is used to generate first control information based on the phase information of the corresponding phase of the input power supply collected by the information acquisition module, and provide the first control information to the control center; the control center adjusts the first control information according to the overall requirements of the load for the power circuit output, and generates second control information including the switch duty cycle and frequency; and provides the second control information to the switch of the corresponding phase.

[0062] Specifically, in this embodiment, the three-phase electricity includes three phases, A phase, B phase and C phase, each phase is connected to the power circuit, the connected power circuit includes a power circuit unit, and the power circuit unit includes 3 circuit groups. Among them, the power circuit also includes a controller corresponding to each one, which is connected to the information acquisition module and the control center, and is used to generate the first control information according to the corresponding phase information of each phase of the input power input collected by the information acquisition module and transmit it to the control center. The information acquisition module here can be a sensor, a monitor, etc., and the specific implementation form and components are not limited, as long as it can meet the requirements of this implementation to obtain the voltage / current information of each phase input of the power circuit and the overall output of the power circuit; the specific generation method of the first control information here is not limited. The control center receives the first control information carrying the phase information of the corresponding phase sent by the controller, generates the second control information according to the output voltage and current information of the current power supply circuit collected by the information acquisition module and the requirements of the load on the voltage and current of the overall output of the power supply circuit, and transmits the second control information to the switch of the circuit group connected to the corresponding phase, thereby controlling the working state of the switch; specifically, the second control information generated by the control center is the duty cycle and frequency information of the switch, and its specific generation method is not limited as long as it can achieve the implementation of the technical method of the present application.

[0063] In one of the preferred embodiments, the circuit group implements power factor tracking through inductance and switches, and also implements dynamic adjustment of voltage boost and voltage reduction according to input / output voltage, current information and the requirements of the connected load for the output voltage.

[0064] Specifically, continue to Figure 1 As shown, the inductor in the circuit group participates in realizing power factor tracking, and also realizes dynamic adjustment of voltage boost and voltage reduction according to the input voltage and the required output voltage of the power supply circuit. The principle of realizing power factor tracking by the inductor in the circuit group disclosed in this embodiment in conjunction with the switch is as follows:

[0065] When the input power is AC input, the voltage period T' after full-wave rectification of the input power is set to the first time interval [if the input power is DC, no rectification is required and the voltage period T' of the input power is directly set to the first time interval]. In this first time interval T', the input voltage changes continuously. Since the inductor has the characteristic of not allowing sudden changes in current according to its parameter characteristics, the time period interval corresponding to the switching frequency of switch K is the second time interval T"; when the second time interval T" is several orders of magnitude smaller than the voltage period T' of the input power, within the T' voltage period range, switch K has completed hundreds or thousands of times of closing and closing, that is, in the process of the input power supply providing the voltage period T' itself changing from trough to peak, because the on / off switching frequency of switch K is relatively high, for controlling the working process of the power supply circuit unit through the working state of switch K, the voltage of the input power supply does not change much locally, and can basically be considered unchanged, that is, the input power supply voltage corresponding to before and after switch K is switched once is considered unchanged. At the same time, the first time interval T' includes a lot of In the case of a second time interval T", that is, when the input voltage changes significantly, the inductor L has undergone multiple charging and discharging processes through the control of the switch K, that is, at this time, the inductor L has completed multiple cycles of loop ① [input power supply + inductor L + capacitor C + transformer T], loop ② [input power supply + inductor L + switch K] and loop ③ [capacitor C + transformer T + switch K] in the above working process. The inductor L can obtain electrical energy through the current input power supply corresponding to a lower voltage, and smoothly transmit the current to the transformer T through the above loop, and further provide it to the power output end, so that only the peak voltage of the input power supply sine wave is not used, but even a very low voltage of the input power supply can be effectively transmitted smoothly, thereby realizing power factor tracking.

[0066] In this embodiment, the inductor can realize power factor tracking in the power supply circuit, which means that the inductor can fully utilize the electric energy of the input power supply with a very low voltage, thereby ensuring that the power factor of the power supply circuit can exceed 99%.

[0067] Furthermore, the inductor of the power supply circuit of the present application can realize the above-mentioned power factor tracking while also realizing the dynamic working process of boosting and bucking according to the specific conditions of the input voltage and the output voltage required by the power supply circuit load and the working state of the switch K. The specific boosting / buckling process and principle are as follows:

[0068] When the voltage provided by the power supply circuit is insufficient to meet the load requirements and a voltage boost is required, the controller controls the switch K to increase the duty cycle of the switch K or reduce the operating frequency of the switch K, that is, to increase the charging time of the inductor L. When the switch is disconnected, the inductor L can transfer more electrical energy to the capacitor of the circuit component and the primary winding of the transformer, and further induce the secondary winding of the transformer to achieve a voltage boost. Furthermore, if the voltage provided by the power supply circuit unit is high and a voltage reduction is required, the controller controls the switch K to reduce the duty cycle of the switch K or increase the operating frequency of the switch, and reduce the charging time of the inductor L, thereby reducing the electrical energy transmitted to the capacitor and transformer in the circuit component to achieve a voltage reduction.

[0069] Here, when the period interval T” corresponding to the working frequency of switch K is higher than the voltage period T’ provided by the input power supply as a whole, that is, T”>>T’, the frequency and duty cycle of switch K are adjusted, and the charging and discharging time of the main inductor are further adjusted to achieve voltage boost / voltage reduction. Specifically, the size of the voltage period T’ provided by the input power supply can be set according to the specific situation of the input power supply. Furthermore, if the input power supply is an alternating current with periodic voltage changes, for example, a sinusoidal alternating current, its frequency is 100HZ, and the corresponding T’=10ms. If the input power supply is a voltage change that does not have obvious periodicity, the value of T’ can be set by analogy with the change period of the sinusoidal alternating current. The specific setting method only needs to meet the requirements of the above description and be able to implement the solution of the present application.

[0070] Specifically, refer to Figure 4 As shown, the inductor cooperates with the switch working state in the power circuit unit to realize power factor tracking and corresponding output required voltage boost and / or voltage reduction, and its specific working process is as follows:

[0071] Step S1, obtaining the current actual input current, input voltage, output voltage, and output current values ​​at high frequency;

[0072] Step S2, comparing the current actual output power obtained with the target output power required by the connected load;

[0073] Step S3, according to the comparison result between the current actual output power and the target output power, adjusting the input current peak value [I_in_peak] at high frequency;

[0074] Step S4, according to the input current peak value [I_in_peak] and the current input phase information [current input voltage / input voltage peak value], the target input current value [I target input current value = I input current peak value * phase information] is determined at high frequency;

[0075] Step S5, comparing the current actual input current value with the target input current value, and determining the duty cycle and frequency adjustment instruction information of the switch at high frequency according to the comparison result;

[0076] Step S6, the switch of the power circuit executes the instruction information at a high frequency to control the charging and discharging time of the inductor in the power circuit so that the current actual input current value of the power circuit is as close as possible to the target input current value.

[0077] Specifically, the circuit group of the power supply circuit of the present application can simultaneously realize functions such as boosting, bucking and power factor tracking under AC input conditions. It is necessary to determine the parameters of the components in the circuit group to ensure that the power supply circuit of the present application has an energy conversion rate of up to 98% or even above 98%. With the same energy conversion rate, the power supply circuit of the present application has lower cost and better circuit stability than the prior art.

[0078] Specifically, the power supply circuit of the present application can simultaneously realize the control of the output power and voltage rise and fall according to the load requirements and the power factor tracking under the condition of periodic fluctuating input. Compared with the prior art, the power supply circuit of the present application which realizes the same function has fewer components, simple connection relationship, low cost and good stability.

[0079] In this embodiment, three-phase electricity is used in the power supply circuit for parallel synthesis at the output end. For each phase, the power factor of the phase is tracked according to the above steps and the dynamic step-up and step-down of the output voltage after parallel synthesis are simultaneously achieved. In the circuit group disclosed in the present application, during the switch-off period, the inductor and the primary winding of the transformer sense the stored energy to the secondary winding of the transformer through the current change of the primary winding of the transformer, that is, the energy that can be sent to the secondary winding of the transformer depends on the amount of energy stored in the inductor and the primary winding of the transformer during the switch-on period. In this case, it can be ensured that when the three-phase electricity is working, the output end is directly parallel synthesized, and there will be no problem of power imbalance between the three circuit groups of the three-phase electricity in parallel.

[0080] In order to ensure that the power supply circuit of the present application has good stability, low cost and other advantages, and the power conversion rate is also relatively high, it is also necessary to determine the parameters of the components of the circuit group in the power supply circuit.

[0081] Principles for determining the parameters of components in the circuit group: The determination of specific component parameters is related to the input voltage, output voltage and output power of the circuit group. First, the maximum input voltage, the maximum output voltage, and the output power of the circuit group must be determined. Here, in the case of AC, the maximum voltage refers to its effective value, and in the case of DC, the maximum voltage refers to the maximum value of the input / output voltage range. According to the ratio of the maximum input voltage and the maximum output voltage and the output power of the power circuit unit, the capacitance parameters, inductance parameters, the inductance of the primary / secondary winding of the transformer and the ratio of the primary / secondary winding, the switch operating frequency range, etc. in the circuit group are determined.

[0082] Specifically, in practice, the inductance of the circuit group and the primary / secondary inductance parameters of the transformer need to be determined by considering:

[0083] When parameters such as the switch operating frequency / duty cycle, the primary inductance of the transformer and the inductance of the inductor do not change, when the input voltage increases, during the switch-on period, the transformer primary winding inductance can store more energy, and during the switch-off period, the energy stored in the transformer primary winding inductance is induced to the transformer secondary winding, which can increase the output power of the circuit group; when the input voltage decreases, the output power of the circuit group can be reduced.

[0084] When parameters such as the maximum input voltage, the inductance of the inductor, the switching operating frequency / duty cycle, etc. do not change, when the primary inductance of the transformer decreases, during the switch-on period, the primary inductance of the transformer can store more energy, and during the switch-off period, the energy stored in the primary inductance of the transformer is induced to the secondary winding of the transformer, which can increase the output power of the circuit group; accordingly, when the inductance of the primary winding of the transformer increases, the output power of the circuit group can be reduced; in the process of determining the inductance of the primary winding of the transformer, it is also necessary to consider that when the primary winding of the transformer stores too much energy, it may cause the transformer to saturate, thereby reducing the energy conversion efficiency.

[0085] In practice, changing the ratio of the number of turns of the primary / secondary winding of the transformer will affect the conversion efficiency of the circuit; specifically, when the input voltage, switching operating frequency / duty cycle, load resistance value, transformer primary winding inductance, inductance, etc. are determined, increasing the number of turns of the secondary winding or reducing the number of turns of the primary winding, that is, reducing the primary / secondary winding ratio, can increase the output voltage; correspondingly, reducing the number of turns of the secondary winding or increasing the number of turns of the primary winding, that is, increasing the primary / secondary winding ratio of the transformer, can reduce the output voltage; by determining the parameters of the transformer through specific scenarios and the aforementioned methods, the conversion efficiency of the power supply circuit can be effectively improved.

[0086] In practice, when the input voltage, switch operating frequency / duty cycle, transformer primary winding inductance, etc. are determined, when the inductance of the inductor decreases, the inductor can store more energy during the switch-on period, and during the switch-off period, the energy stored in the inductor charges the primary side of the transformer, and the transformer primary winding then senses the energy to the transformer secondary winding, which can increase the output power of the circuit group; when the inductance of the inductor increases, the output power of the circuit group can be reduced.

[0087] When determining the frequency range of the switch, it is necessary to consider: when the parameters of other components in the circuit group remain unchanged, when the switching frequency is lowered, the energy storage time t of the switch closure in a single cycle becomes longer and the frequency f decreases; during the switch closure period, the energy stored in the inductor and the primary side of the transformer increases, and the output power of the circuit group increases. Correspondingly, when the switching frequency is increased, the output power of the circuit group will decrease. In addition, as the switching frequency increases, the switch will generate switching losses at the moment of turn-on and turn-off. Increasing the frequency of the switch will increase the switching losses. Here, the conversion efficiency of the transformer also needs to be considered. Different magnetic cores have different corresponding inductances and conversion efficiencies at different frequencies. Too low a frequency, for example, below 30K, may cause the transformer to saturate, resulting in a decrease in conversion efficiency; too high a frequency, for example, above 500K, may cause a huge change in the inductance of the transformer, reducing the conversion efficiency.

[0088] The process of determining the parameters of the capacitor, as mentioned above, is that the capacitor stores energy during the switch-off period, and during the switch-on period, the capacitor resonates with the primary winding of the transformer and transfers the stored energy to the primary winding of the transformer. If the capacitance of the capacitor is too small, the energy stored on the capacitor will be insufficient during operation, reducing the output power of the power circuit unit and thus reducing the conversion efficiency; if the capacitance of the capacitor is too large, when the input voltage is AC, the voltage of the capacitor cannot keep up with the changes in the input voltage of AC, resulting in calculation difficulties during the power factor tracking process and reduced power conversion efficiency.

[0089] 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 0.3-7.6, according to the above parameter selection rules, when the parameter of the capacitor is less than 30nF, the voltage across the capacitor rises too fast during the off-cycle of the switch, causing the voltage across the switch to rise too fast, which may damage the switch, or a switch with a higher voltage resistance must be used, increasing the cost of the switch; when the capacitor parameter is greater than 3μF, the current in the primary winding inductance of the transformer rises too fast during the on-time of the switch, and at the moment the switch is disconnected, the voltage spike caused by the leakage inductance of the transformer is too high, which may damage the switch, or a switch with a higher voltage resistance must be used, increasing the cost of the switch. When the transformer primary winding inductance is less than 10μH, the transformer parameters are difficult to balance. For example, if the number of turns is too small, it is easy to saturate and cannot carry enough power; or if the number of turns is enough, but the air gap of the magnetic core is too large, the leakage flux is serious and the efficiency is reduced; when the transformer primary inductance is greater than 1000μH, the energy stored in the transformer primary inductance decreases during the energy storage period of the switch conduction, and the frequency must be reduced to carry enough power. When the frequency is too low, the transformer conversion efficiency is low and it is easy to saturate. When the transformer primary / secondary winding ratio is less than 1:5, the transformer manufacturing process is difficult, which may cause the transformer secondary winding leakage inductance to be too large. When the switch is turned on, the secondary winding leakage inductance causes a huge oscillation in the switch current, which significantly reduces the efficiency; when the transformer primary / secondary winding ratio is greater than 5:1, the transformer manufacturing process is difficult, which may cause the transformer primary winding leakage inductance to be too large. At the moment of switch disconnection, the primary winding leakage inductance causes a huge voltage oscillation at both ends of the switch, which may damage the switch, or a switch with a higher withstand voltage needs to be selected, which will increase the cost of the switch.

[0090] Specifically, in this embodiment, according to the above-mentioned parameter selection principle, the parameters of the inductance in the circuit group are further determined. Since the electric energy is dynamically distributed between the inductance and the primary winding of the transformer according to the magnitude relationship between the inductance value and the inductance value of the primary winding of the transformer during the operation of the circuit group, the inductance parameter needs to have a relatively wide range, specifically 1μH-10mH. When the inductance stores more energy and participates in more energy transmission, its parameter value can be set smaller, and the parameter range can be set to 1μH-100μH; when it does not participate in energy transmission or participates in less energy transmission, its parameter value can be set larger, and the parameter range can be set to 2mH-10mH.

[0091] Furthermore, the following conditions need to be considered when determining the specific value of the inductor parameter:

[0092] If the inductance of the inductor is selected to be close to the inductance of the primary winding of the transformer, for example but not limitation: the inductance of the inductor and the inductance of the primary winding of the transformer are both designed to be 10μH-30μH, then in the energy storage period when the switch is turned on, the energy stored in the primary winding of the transformer and the inductor are the same. The advantage of this is that the inductor shares the energy transmission task, and the inductor and the primary winding of the transformer balance the heating points. At the same time, requirements are put forward for the core material of the inductor. The loss of the selected core during the energy storage and transmission process needs to be carefully tested to avoid inductor saturation, which may lead to an increase in the inductor cost.

[0093] If the inductance of the inductor is much larger than the inductance of the primary winding of the transformer, for example but not limitation: the inductance of the inductor is designed to be 800μH-1000μH, and the inductance of the transformer is designed to be 10μH, then in the energy storage cycle, the primary inductance of the transformer will dominate the energy storage. The advantage of this is that it reduces the energy transfer of the inductor and saves the cost of the inductor core.

[0094] The inductance of the inductor is set much lower than the inductance of the primary winding of the transformer. For example, but not limitation, the inductance of the inductor is designed to be 10μH, and the inductance of the transformer is designed to be 1000μH. This will result in the energy storage of the inductor far exceeding the energy storage of the primary winding of the transformer during energy storage. The inductance of the inductor and the inductance of the primary winding of the transformer are both set to be relatively large. For example, but not limitation, the inductance of the inductor is designed to be 100μ-1000μH, and the inductance of the transformer is designed to be 100μ-1000μH. This will result in the switching frequency having to be set in a very low range to output power above 200W, and it is easy to cause saturation of the transformer and inductor, which puts very high requirements on the setting of the transformer and inductor parameters. In practice, the power conversion efficiency of the circuit group of this scheme is low.

[0095] Specifically, in this embodiment, the operating frequency of the switch is related to multiple parameters. When the parameters such as the inductance of the primary winding of the transformer, the inductance of the inductor, the switch duty cycle, the input voltage, and the load remain unchanged. Reducing the operating frequency of the switch will increase the output power of the circuit group; increasing the operating frequency of the switch will reduce the output frequency of the circuit group. It should be noted that too low a switching frequency can easily cause saturation of the inductor and the transformer, and too high a switching frequency can lead to increased switching losses. Specifically, the switching frequency needs to be adjusted dynamically in real time according to the fluctuation of the input voltage and the dynamic requirements of the output voltage.

[0096] Furthermore, in the process of dynamically boosting and reducing the voltage according to the output requirements of the power supply circuit, it is necessary to calculate and adjust the switch duty cycle and frequency in real time. The process of realizing power factor tracking in the power supply circuit is to adjust the switch duty cycle and frequency so that the actual input current approaches the target input current that is synchronized with the input voltage and shows a regular change of the input voltage in real time. Therefore, the operating frequency range of the switch needs to meet the power factor tracking while being dynamically adjusted. Specifically, its range is about 30K-500K.

[0097] In one preferred embodiment, the maximum input voltage V 入 With the maximum output voltage V 出 The ratio is V 入 :V 出 =0.3-7.6, when the output power is greater than 200W, the parameter range of the capacitor is 35nF-2.9μF, the inductance range of the primary winding of the transformer is 15μH-950μH; the ratio range of the primary winding / secondary winding of the transformer is R 原 : R 副 =1∶5-5∶1.

[0098] Specifically, when the output power of the circuit group is greater than 200W, the ratio of the maximum input voltage to the maximum output voltage is 0.3-7.6, the parameter of the capacitor is set to 35nF-2.9μF, the primary inductance of the transformer is 15μH-950μH, the inductance parameter range is 1μH-10mH, and the ratio of the primary / secondary winding of the transformer is 1:5-5:1, the power conversion rate of the circuit group can reach more than 96%, and the power conversion rate can be as high as more than 98% in some specific scenarios, see the specific experimental data of Examples 1 to 38 in Table 1. Compared with the prior art, the power supply circuit of this embodiment has a higher power conversion rate, and at the same time, the power supply circuit uses only a few components, and achieves an ultra-high power conversion rate at a low cost, and can realize dynamic boost and buck according to the needs of the load. Compared with the circuit with the same power conversion rate in the prior art, the power supply circuit of the present application has strong stability, low cost, low power loss and more energy saving.

[0099] The ratio of the maximum input voltage to the maximum output voltage of the circuit group is V 入 :V 出 =0.3-0.9, when the output power is 200W-1000W, the inductance range of the primary winding of the transformer is 15μH-950μH, the parameter range of the capacitor is 105nF-2.9μF, and the ratio range of the primary / secondary winding of the transformer is R 原 : R 副 =1∶5-1∶1.

[0100] Specifically, this embodiment provides a parameter range of the corresponding capacitor, transformer primary winding, and transformer primary secondary winding ratio in the circuit group components when the power supply circuit output power is 200W-1000W and the ratio of the maximum input voltage to the maximum output voltage is 0.3-0.9. According to the above parameter determination principle and process, after determining the specific maximum input voltage, maximum output voltage, and output power, the specific parameters of the corresponding components are selected and determined within the parameter range of the corresponding components provided in this embodiment to meet the power factor tracking and the dynamic adjustment of the boost and buck required by the output end, and the power conversion rate can be as high as 98% or more. The specific parameter experimental data and test results are shown in the specific experimental data embodiments 1 to 11 in Table 1. This embodiment can be applied to the micro-inverter power supply circuit scenario. Under the same function and the same power conversion rate as the prior art, the power supply circuit components of this application are obviously less than the components of the prior art circuit, and the energy loss is less. The cost of this application is lower and the circuit stability is stronger.

[0101] Specifically, as an example but not limiting, when the maximum input voltage is 300V, the maximum output voltage is about 300V, and the output power is 1000W, according to the above parameter design principles, the inductance of the primary winding of the transformer is set to about 60μH-950μH, the capacitance parameter is set to about 105nF-500nF, and the primary / secondary winding ratio of the transformer is set to 1:1. At this time, the energy conversion rate of the corresponding power supply circuit is close to 98%. For specific parameter experimental data and test results, please see the specific experimental data embodiment 24 in Table 1.

[0102] The above embodiment can be applied in the field of solar photovoltaic, with a DC input of 300V, an AC output of about 300V peak, an output power of 1000W, a maximum input voltage and a maximum output voltage of about 1:1, and the inductance of the inductor and the primary winding of the transformer should be relatively large. For example, the inductance of the primary winding of the transformer is set to 60μH, and the inductance is set to 1mH. Since the ratio of the maximum input voltage to the maximum output voltage is about 0.9, the primary / secondary inductance of the transformer used is about 1:1. When the ratio of the primary / secondary of the transformer is close, the transformer processing technology can save costs, and the leakage inductance is easy to control.

[0103] In the application scenario of this embodiment, the capacitance parameter is about 105nF-500nF; in practice, for capacitors less than 100nF, during the energy storage period when the switch is closed, the energy in the capacitor is too little and cannot provide enough energy to the primary winding of the transformer, resulting in a decrease in the energy conversion efficiency of the circuit group; for capacitors greater than 500nF, during the energy storage period when the switch is closed, the capacitor stores too much energy, which charges the primary winding inductance of the transformer, easily resulting in a large charging current. At the moment the switch is disconnected, a voltage spike is generated due to the primary leakage inductance of the transformer, resulting in the need to select a switch with a higher voltage resistance, increasing costs.

[0104] In this embodiment, since the ratio of the maximum input voltage to the maximum output voltage is 1, the primary / secondary inductance of the transformer used is about 1: 1. When the primary / secondary ratio of the transformer is close, the transformer processing technology can save costs and the leakage inductance is easy to control.

[0105] At the same time, you can choose to distribute the energy stored in the energy storage cycle between the transformer and the inductor. Increase the inductor inductance and reduce the transformer inductance. The energy stored in the primary side of the transformer during the energy storage cycle of opening and closing will account for a larger proportion, and the inductor will account for a smaller proportion. Reduce the inductor inductance and increase the transformer inductance. The energy stored in the primary side of the transformer during the energy storage cycle of opening and closing will account for a smaller proportion, and the inductor will account for a larger proportion.

[0106] In one preferred embodiment, the ratio of the maximum input voltage to the maximum output voltage of the circuit group is V 入 :V 出 =5.2-7.6, when the output power is 1000W-2000W, the primary inductance range of the transformer is 55μH-240μH, the capacitance parameter range is 210nF-790nF, and the primary / secondary winding ratio range of the transformer is R 原 : R 副 =2∶1-5∶1.

[0107] Specifically, this embodiment provides a parameter range of the corresponding capacitor, transformer primary winding, and transformer primary secondary winding ratio in the circuit group components when the circuit group output power is 1000W-2000W and the ratio of the maximum input voltage to the maximum output voltage is 5.2-7.6. According to the above parameter determination principle and process, after determining the specific maximum input voltage, the maximum output voltage, and the output power, the specific parameters of the corresponding components are selected and determined within the parameter range of the corresponding components provided in this embodiment to meet the power factor tracking and the dynamic adjustment of the boost and buck required by the output end, and the power conversion rate can be as high as 98% or more. The specific parameter experimental data and test results are shown in the specific experimental data embodiments 12 to 20 in Table 1. This embodiment can be applied to the power supply circuit scene in the communication field. Under the same function and the same power conversion rate as the prior art, the power supply circuit components of this application are obviously less than the components of the prior art circuit, and the energy loss is less. The cost of this application is lower and the circuit stability is stronger.

[0108] As an example and not a limitation, when the input voltage is a 220V sine wave, that is, the maximum input voltage is about 311V, the maximum output voltage is about 40V, and the output power is 1000W, according to the above parameter design principles, the inductance of the primary winding of the transformer is set at about 150μH-240μH, the capacitance parameter is set at about 210nF-500nF, and the primary / secondary winding ratio of the transformer is set at about 5:1. At this time, the corresponding power conversion rate is above 96%.

[0109] Specifically, in this embodiment, the output voltage is only 40V, and the output half-wave rectifier module can use a switch device instead of a diode. In the case of low voltage, the output current is very large, and a switch device with relatively low internal resistance needs to be selected.

[0110] As an example but not limitation, when the input voltage is a 380V sine wave, that is, the maximum input voltage is about 540V, the maximum output voltage is about 100V, the ratio of the maximum input voltage to the maximum output voltage is about 5:1, and the output power is 2000W, according to the above parameter design principles, the transformer primary winding inductance is set at about 55μH-150μH, the capacitance parameter is set at about 400nF-790nF, and the transformer primary / secondary winding ratio is set at about 2:1, and the corresponding power conversion rate is above 97%. With the same function and the same power conversion rate as the prior art, the number of power circuit components of the present application is much smaller than the same type of products on the market, the cost is much lower than the market products, and the circuit stability is higher.

[0111] This embodiment is a situation 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 1:1 transformer is used, the switch duty cycle may be too small and the frequency may be too low, resulting in low transformer conversion efficiency, which in turn reduces the overall power conversion efficiency of the power supply circuit. Using a transformer of about 2:1-3:1 can solve this problem well and improve the circuit conversion efficiency. At this time, it should be noted that the primary leakage inductance of the 2:1-3:1 transformer will increase. If the primary leakage inductance is too large, a voltage spike will be generated at the moment the switch is turned off, causing damage to the switch, or a switch with a higher withstand voltage will be required, increasing the cost. It is recommended here to use copper foil as the primary and secondary coils, and to make a transformer by winding the primary and secondary coils in parallel to reduce the primary and secondary leakage inductance of the transformer.

[0112] In this embodiment, the output voltage is only 100V. It is recommended to use switching components instead of diodes for output half-wave rectification, and it can be considered to set the switch of the circuit group to a switching component formed by multiple switching devices in parallel to reduce conduction loss.

[0113] In one preferred embodiment, the ratio of the maximum input voltage to the maximum output voltage of the circuit group is V 入 :V 出 =0.7-1.45, when the output power is 1000W-2000W, the primary inductance range of the transformer is 35μH-950μH, the capacitance parameter range is 55nF-2.9μF, and the primary / secondary winding ratio range of the transformer is R 原 : R 副 =1∶2-2∶1.

[0114] Specifically, this embodiment provides a parameter range of the ratio of the capacitor, the primary winding of the transformer, and the primary and secondary windings of the transformer in the circuit group components when the output power of the circuit group is 1000W-2000W and the ratio of the maximum input voltage to the maximum output voltage is 0.7-1.45. According to the above-mentioned parameter determination principle and process, after determining the specific maximum input voltage, the maximum output voltage and the output power, the specific parameters of the corresponding components are selected and determined within the parameter range of the corresponding components provided in this embodiment to meet the power factor tracking and the dynamic adjustment of the boost and buck required by the output end, and the electric energy conversion rate can be as high as 98%. The specific parameter experimental data and test results are shown in the specific experimental data embodiments 21 to 30 in Table 1. This embodiment can be applied to the power circuit scene in the automotive field. Under the same function and the same electric energy conversion rate as the prior art, the power circuit components of the present application are obviously less than the components of the prior art circuit, and the energy loss is less. The present application has lower cost and stronger circuit stability.

[0115] As an example but not limitation, when the input voltage is a 220V sine wave, that is, the maximum input voltage is about 311V, the maximum output voltage is about 200V, and the output power is 2000W, according to the above parameter design principles, the inductance range of the primary winding of the transformer is set to about 35μH-950μH, the capacitance parameter range is set to about 500nF-2900nF, and the primary / secondary winding ratio of the transformer is set to about 2:1, the power conversion rate of the power supply circuit can be as high as over 97%.

[0116] As an example and not a limitation, when the input voltage is a 380V sine wave, that is, the maximum input voltage is about 540V, the maximum output voltage is about 1000V, the ratio of the maximum input voltage to the maximum output voltage is about 0.7, and the output power is 1000W, according to the above parameter design principles, the inductance of the primary winding of the transformer is set at about 150μH-950μH, the capacitance parameter is set at about 55nF-500nF, and the primary / secondary winding ratio of the transformer is set at about 1:2. At this time, the corresponding power conversion rate is above 98%.

[0117] In this embodiment, when the output voltage is 1000V, the output voltage is too high. If a 1:1 transformer is used, the output voltage will be induced to the primary side of the transformer, superimposed with the capacitor voltage, resulting in too high withstand voltage of the switch, damaging the switch. When a 1:2 transformer is used, during the switch disconnection period, after the output voltage 1000V is induced to the primary side, the primary voltage is only 500V. After superimposing the capacitor voltage, the withstand voltage during the switch off period is greatly reduced, the selection space of the switch is increased, and the cost is greatly reduced. Therefore, it is necessary to set the ratio of the primary / secondary winding of the transformer to 1:2. This setting can greatly reduce the duty cycle of the switch and improve the power conversion efficiency of the circuit group. At the same time, the output voltage of 1000V is converted to the primary side through the primary-secondary 1:2 transformer, which can greatly reduce the withstand voltage of the switch during the off period, increase the selection space of the switch tube, and greatly reduce the cost.

[0118] In one preferred embodiment, the ratio of the maximum input voltage to the maximum output voltage of the circuit group is V 入 :V 出 =2.3-4.8, when the output power is 2000W-10000W, the primary inductance range of the transformer is 55μH-240μH, the capacitance parameter value range is 220nF-790nF, and the primary / secondary winding ratio range of the transformer is R 原 : R 副 =1∶1-2∶1.

[0119] Specifically, this embodiment provides a parameter range of the corresponding capacitor, transformer primary winding, and transformer primary secondary winding ratio in the circuit group components when the output power of the circuit group is 2000W-10000W and the ratio of the maximum input voltage to the maximum output voltage is 2.3-4.8. According to the above parameter determination principle and process, after determining the specific maximum input voltage, the maximum output voltage, and the output power, the specific parameters of the corresponding components are selected and determined within the parameter range of the corresponding components provided in this embodiment to meet the power factor tracking and the dynamic adjustment of the boost and buck required by the output end, and the electric energy conversion rate can be as high as 98%. The specific parameter experimental data and test results are detailed in the specific experimental data embodiments 31 to 35 in Table 1. This embodiment can be applied to scenes requiring high-power power supply. Under the same function and the same electric energy conversion rate as the prior art, the power supply circuit components of this application are obviously less than the components of the prior art circuit, and the energy loss is less. The cost of this application is lower and the circuit stability is stronger.

[0120] Ginseng Figure 2 Combined with Figure 3-1 , 3-2 As shown in 3-3 and 3-4, when the output ends of the three circuit groups corresponding to the three-phase electricity included in the power supply circuit unit are connected in parallel, the process of solving the ripple problem of the power supply circuit is as follows:

[0121] Ginseng Figure 2 As shown, three circuit groups are connected to the three-phase power, and when the switch of the corresponding circuit group is closed, the inductance of each circuit group is charged through the above loop ②, and the resonant circuit formed by loop ③ [capacitor C+transformer T+switch K] adjusts the magnetic field direction of the primary winding of the transformer. At this time, the circuit group does not transfer energy to the secondary winding of the transformer. When the switch is turned off, the transformer transfers energy to the secondary winding through the above loop ① [input power supply+inductor L+capacitor C+transformer T], and charges the connected output capacitor through the output end of the circuit group. The output capacitor is then connected to the load to provide electrical energy to the load.

[0122] As mentioned above, if only the output end of one circuit group is connected to the output capacitor, and the output capacitor is connected to the load to provide electrical energy to the load, when the voltage of the input steamed wave is zero or the voltage is low, the output capacitor needs to use its own stored electrical energy to provide electrical energy to the load, otherwise there will be a large ripple problem, and it is necessary to set an output capacitor with larger parameters to alleviate the ripple problem, which increases the cost.

[0123] The three phase differences of three-phase electricity are 120°. When the resistive load connected to each phase of the three-phase electricity is the same, the output power is constant. The three circuit groups are connected to the three-phase electricity at the same time, and the output ends of the three circuit groups are connected in parallel, that is, the output ends of the three circuit groups are connected to the positive electrode of the output capacitor at the same time, and the other ends are connected to the negative electrode of the output capacitor at the same time. In this way, when the input voltage of the first circuit group in the power supply circuit unit is low, the other two circuit groups, because of the phase difference of 120°, make the overall input power of the three-phase power input power supply circuit unchanged, and are not in a state of low input power, which can ensure the total input power, and will not fluctuate due to the 50Hz power frequency phase. Because the inductor has the function of power factor tracking, and the power of the three-phase electricity is constant, the output power of the power supply circuit unit is constant at this time, and the voltage ripple is basically eliminated, so that a stable voltage output can be provided for the load.

[0124] Take the input of 380V sine wave AC and the output requirement of 1000V / 40kW as an example. When the input is single-phase electricity, the reference Figure 3-1 As shown in the figure, the frequency of the single-phase power after full-wave rectification is 100HZ. Figure 3-2 As shown in the figure, when the output capacitance is 3mF, the corresponding output voltage has a ripple with a frequency of 100HZ and an amplitude of about 28V; when the input is three-phase electricity, there is an angle of 120° between the three 380V sine waves compared with single-phase electricity. Figure 3-3 and Figure 3-4 As shown, after the output ends of the circuit groups connected to each phase of the three-phase electricity are connected in parallel, the corresponding output voltage has a ripple with a frequency of 300 Hz and an amplitude of about 6 volts. It can be seen that the ripple is significantly reduced, thereby solving the problems of battery overcharge / output overcurrent, heating and reduced life caused by frequent charging and discharging of the output capacitor, and output capacitors with smaller parameter values ​​can be selected to reduce costs.

[0125] In one of the preferred embodiments, after the output ends of the three circuit groups in the power circuit units in the multiple power circuit units are connected in parallel, the outputs of the multiple power circuit units are connected in series or in parallel.

[0126] In one of the preferred embodiments, after the output ends of the three circuit groups corresponding to the three-phase electricity included in the multiple power supply circuit units are connected in parallel, the outputs of the power supply circuit units are connected in series or in parallel.

[0127] Specifically, it can be seen from the above that after the three circuit groups of each power supply circuit unit are respectively connected to the three-phase power, the output end of each circuit group is connected in parallel to solve the ripple problem. When the power supply circuit includes multiple power supply circuit units, the output ends of the multiple power supply circuit units can be combined in series / parallel to provide a wider output voltage / power range to meet the different voltage requirements of various loads.

[0128] In practice, when the power supply circuit includes multiple power supply circuit units, and each power supply circuit unit includes three circuit groups connected to three-phase electricity, the output ends of the three circuit groups in each power supply circuit unit are connected in series / parallel, and the multiple power supply circuit units provide power output ends, which can be connected in series or parallel, or in a combination of series and parallel, through various switch control devices / modules.

[0129] Here, there is no restriction on the control device / module that specifically implements the series / parallel combination of multiple power supply circuit unit output terminals. Any current or future existing technology that can implement the switch control device / module scheme of the series / parallel combination of multiple power supply circuit unit output terminals, as long as the scheme can be directly applied to the series / parallel combination of multiple power supply circuit unit output terminals in this embodiment, or does not require technical personnel in this field to expend creative labor to modify the scheme to be applicable to the series / parallel combination of multiple power supply circuit unit output terminals in this embodiment, then these schemes that can implement the switch control device / module are all within the protection scope of this application, such as relays, electromagnetic switches, etc.

[0130] In one preferred embodiment, the power supply circuit further includes an input rectifier module for providing a DC input to the inductor in the circuit group, wherein the multiple circuit groups connected to each phase in the multiple power supply circuit units share a full-wave rectifier module.

[0131] In one preferred embodiment, the half-wave rectification module realizes half-wave rectification through a diode.

[0132] Specifically, the half-wave rectifier module provided in this embodiment is connected to one end of the secondary winding of the transformer, and its specific working principle is as follows:

[0133] After the switch of the circuit group is changed from closed to open, the inductor and the primary winding of the transformer that have been charged during the switch closing period are discharged, the capacitor is charged, and the secondary winding of the transformer is induced by the current change of the primary winding to obtain electric energy. At this time, the current of the secondary winding of the transformer is output to the output capacitor or the load through the half-wave rectifier module to provide or store electric energy; when the switch of the circuit group is changed from open to closed, the capacitor in the circuit group forms a loop with the primary winding of the transformer and the switch. Because the capacitor does not allow sudden voltage changes, the capacitor resonates with the primary winding of the transformer, and the current direction in the primary winding of the transformer is opposite to the current direction during the switch-off period. Because the half-wave rectifier module is set on the secondary winding of the transformer, a loop cannot be formed. When the primary winding of the transformer forms a resonant loop with the capacitor and the closed switch, no induced current is generated in the secondary winding of the transformer.

[0134] It can be seen from this that as long as the half-wave rectifier module can realize the unidirectional conduction of the secondary winding current of the transformer, there is no restriction on the specific circuit or components for realizing half-wave rectification. Any circuit scheme that can realize half-wave rectification in any current or future existing technology, as long as the scheme can be directly applied to the unidirectional conduction of the secondary winding current of the transformer in this embodiment, or does not require the technical personnel in this field to make creative efforts to modify the scheme to be applicable to the unidirectional conduction of the secondary winding current of the transformer in this embodiment, then these circuit schemes that can realize half-wave rectification are all within the protection scope of this application, such as diodes / MOS tubes with unidirectional conduction function, and switching tubes controlled to be unidirectional conduction.

[0135] Furthermore, the diode is used as a half-wave rectifier module, and the unidirectional output of the secondary winding of the transformer is realized by connecting the above diode to the corresponding output end of the corresponding secondary winding of the transformer. The diode itself has the property of unidirectional conduction. The half-wave rectification is realized by the diode, and the control circuit is simple and the performance is stable.

[0136] In one of the preferred embodiments, the half-wave rectifier module realizes half-wave rectification through a first switch and a first controller that controls the first switch; in one of the preferred embodiments, the first controller controls the switching mode of the first switch according to the mode in which the controller of the power supply circuit unit controls the switch to induce electric energy of the secondary winding of the transformer.

[0137] Specifically, this embodiment implements half-wave rectification of the output of the secondary winding of the transformer through a switch tube, and at this time the switch tube is controlled by a switch tube controller.

[0138] Furthermore, the working state of the switch tube determines whether the secondary winding of the transformer can form a loop, that is, when the switch tube is disconnected, it cannot form a loop, and when the switch tube is closed, it can form a loop; at the same time, after the switch of the circuit group is closed, the capacitor in the circuit group charges the primary winding of the transformer and the two form resonance, and the secondary winding of the transformer cannot form a loop, that is, at this time the switch tube needs to be disconnected. The switch tube controller needs to control the working state of the switch tube according to the working state of the switch in the power circuit unit. According to the above analysis, when the switch of the circuit group is in a closed state, the switch tube controller needs to control the switch to be in an open state. This embodiment realizes the function of half-wave rectification of the secondary winding output of the transformer by setting a switch tube controller and a corresponding switch tube; in some scenarios, the switch has lower energy loss and higher power conversion rate than the diode, such as a scenario with a low output voltage, such as less than 160 volts.

[0139] In one of the preferred embodiments, the switch of the circuit group of the power circuit is realized by a bidirectional switch or a controllable switch device.

[0140] In practice, the selection of switch components is also related to the setting of the operating frequency of the switch. For ordinary silicon-based MOS tubes, the maximum frequency is recommended to be limited to 150K; for silicon carbide MOS tubes, the maximum frequency is recommended to be limited to 500K; for IGBT switch tubes, the maximum frequency is recommended to be limited to 40K; for gallium nitride MOS tubes, the maximum frequency is recommended to be limited to 800K. The switch in this embodiment is a general high-frequency switch with a withstand voltage of 150V on the market, such as a high-frequency switch with a model of NCEP15T14, and the corresponding switch operating frequency range is: 50K-200K.

[0141] In fact, the switch of the circuit group of the power circuit unit carries the function of connecting and disconnecting the circuit according to the control information of the corresponding controller. Here, the specific control method of the controller controlling the switch is not limited, that is, the method or path for the controller to provide the control signal to the switch is not limited, and it can be wireless or wired. Any scheme that can realize the signal transmission of the controller controlled switch in any existing technology now or in the future, as long as the scheme can be directly applied to the controller in this embodiment to transmit the control signal to the switch it controls, or does not require the technical personnel in this field to make creative labor to modify the scheme and apply it to this embodiment, then these schemes that can realize the control signal transmission from the controller to the switch it controls are within the protection scope of this application.

[0142] Furthermore, there is no restriction on the specific form of the switch or controller or the switch and its controller for realizing the disconnection and connection of the circuit in the circuit group. Any switch or controller or the scheme of the switch and its controller that can realize the disconnection and connection of the circuit in any existing technology now or in the future, as long as the scheme can be directly applied to the function of disconnecting and connecting the circuit in the scalable power supply circuit of this embodiment, or does not require the technical personnel in this field to make creative efforts to modify the scheme and apply it to this embodiment, then these switches or controllers or the schemes of the switch and its controller that can realize the disconnection and connection of the circuit are all within the protection scope of this application.

[0143] In one preferred embodiment, the transformer leakage inductance value in the power supply circuit is less than 1.5%.

[0144] Specifically, during the operation of the power circuit unit, when the switch of the circuit group is closed, the input power is used to charge the inductor. At the moment the switch is disconnected, the current of the entire circuit is large. At this time, the leakage inductance of the transformer will cause a large voltage peak to be generated at both ends of the switch. The switch may be damaged by the high voltage. To ensure that the power circuit can operate normally and stably, the leakage inductance value range of the transformer here needs to be less than 1.5%.

[0145] Furthermore, the specific structure of the transformer that complies with the power supply circuit of the present application is not limited here. Any structural scheme of the transformer that can achieve a leakage inductance of less than 1.5% in any current or future existing technology, as long as the scheme can be directly applied to the function of the transformer in the power supply circuit unit of this embodiment, or does not require technical personnel in this field to make creative efforts to adapt the scheme to this embodiment, then these schemes that can achieve a transformer structure with a leakage inductance less than 1.5% are all within the protection scope of the present application.

[0146] In one of the preferred embodiments, the transformer structure in the power supply circuit is copper foil or U-shaped metal sheet, and the winding method is parallel winding.

[0147] Specifically, this embodiment discloses the structure and winding method of the transformer in the circuit group. The magnetic core structure of the transformer is selected to be a thin metal sheet, or it can be a U-shaped copper sheet. The winding method of the primary and secondary sides of the transformer is a parallel winding method. This can reduce the leakage inductance of the transformer and meet the operating needs of the power supply circuit.

[0148] Ginseng Figure 4 As shown, the present application also provides a method for realizing power factor tracking and output voltage rise and fall control based on the above power supply circuit, the method comprising:

[0149] Step S1, obtaining the current actual input current, input voltage, output voltage, and output current values ​​at high frequency;

[0150] Step S2, comparing the current actual output power obtained with the target output power required by the connected load;

[0151] Step S3, according to the comparison result between the current actual output power and the target output power, adjusting the input current peak value [I_in_peak] at high frequency;

[0152] Step S4, according to the input current peak value [I_in_peak] and the current input phase information [current input voltage / input voltage peak value], the target input current value [I target input current value = I input current peak value * phase information] is determined at high frequency;

[0153] Step S5, comparing the current actual input current value with the target input current value, and determining the duty cycle and frequency adjustment instruction information of the switch at high frequency according to the comparison result;

[0154] Step S6, the switch of the power circuit executes the instruction information at a high frequency to control the charging and discharging time of the inductor in the power circuit so that the current actual input current value of the power circuit is as close as possible to the target input current value.

[0155] Specifically, in the above step S1, the current actual input current, input voltage, output voltage, and output current values ​​are obtained at high frequency. High-frequency acquisition is required to obtain the current actual input and actual output of the power supply circuit, wherein the specific acquisition or acquisition method is not limited, and it can be obtained through the acquisition unit of the controller or through other methods. The acquired information is transmitted to the controller for determining the switch duty cycle and frequency adjustment instruction information. The frequency of the high frequency can refer to the frequency of the switch in the power supply circuit. For example, it can be equal to the switching frequency or less than the switching frequency. The frequency of the high frequency here can also be changed according to actual conditions, and there is no specific limitation.

[0156] In the above step S2, the current actual output power obtained is compared with the target output power required for the connected load. When the scenario of the connected load or the use of the 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 compared with the target output power. When the current actual output power is greater than the target output power, it means that the actual output power is higher than the target output power, and the actual output power needs to be reduced. When the actual output power is less than the target output power, it means that the actual output does not meet the target output power requirements and the actual output power needs to be increased.

[0157] In the above step S3, the input current peak value [I_in_peak] is determined at high frequency according to 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 input current peak value is increased to increase the current actual output voltage or current, and further increase the actual output power to meet the needs of the load; if the actual output power is greater than the target output power, the input current peak value is reduced to reduce the current actual output voltage or current, and further reduce the output power to meet the needs of the load. The increase or decrease amplitude of the input current peak value needs to consider the difference between the actual output power and the target output power. For example, if the difference between the two exceeds a preset value, the increase amplitude of the input current peak value is increased to quickly meet the needs of the load, etc. The determination of the input current peak value is a high-frequency determination and high-frequency adjustment process, and the method for determining the increase / decrease amplitude is not limited, as long as it meets the requirements of the target output at the load end.

[0158] In the above step S4, according to the input current peak value [I_in_peak] and the current input phase information [current input voltage / input voltage peak value], the target input current value [I target input current value = I input current peak value * phase information] is determined at high frequency, wherein the current input phase information is the ratio of the current actual input voltage provided by the current input power supply to the power supply circuit to the peak value of the periodically fluctuating voltage provided by the input power supply to the power supply circuit, and the target input current value is the product of the input current peak value determined in the above step S3 and the phase information, that is:

[0159] I 目标输入电流值 =I_in_peak*V 当前实际输入电压 / V 输入电压峰值

[0160] In the above step S5, the current actual input current value is compared with the target input current value, and the duty cycle and frequency adjustment instruction information of the switch are determined at high frequency according to the comparison result. Specifically, when the current actual input current value is less than the target input current value, instruction information for controlling the switch to reduce the frequency and increase the switch duty cycle is generated in the controller, and the working state of the switch is controlled to further control the charging time of the inductor, thereby increasing the input current to meet the needs of power factor tracking. At the same time, the output is controlled by approaching the current actual input current to the target input current value; otherwise, when the current actual input current value is greater than the target input current adjustment value, instruction information for controlling the switch to increase the frequency and reduce the switch duty cycle is generated in the controller, and the working state of the switch is controlled to further control the charging time of the inductor, thereby reducing the input current to meet the needs of power factor tracking. At the same time, the output is controlled by approaching the current actual input current to the target input current value. Specifically, the magnitude of the switch duty cycle is controlled to be reduced or increased, and the magnitude of the switch frequency is increased or decreased according to the difference between the current actual input current value and the target input current value. The specific implementation method and process are not limited, and ordinary technicians in this field can try to set it according to the actual scenario. At the same time, the target input current value here includes the phase information of the current input voltage, that is, the phase information of the current input power supply is taken into account when adjusting the current actual input current value according to the target input current value, ensuring that the current actual input current value is always close to the target input current value and fluctuates around the target input current value, so that the power supply circuit has the ability of PFC (power factor tracking).

[0161] In the above step S6, the switch of the power supply circuit executes the instruction information at high frequency, controls 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 switch of the power supply circuit executes the instruction sent by the controller to adjust the current duty cycle or frequency at high frequency, controls the charging and discharging time and frequency 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 realizing the control of the output power while realizing power factor tracking, that is, dynamic adjustment of the boost and buck according to the output requirements.

[0162] The power supply circuit of the present application can simultaneously realize power factor tracking and a method for controlling the output voltage rise and fall. Compared with the prior art, it has fewer components, simpler connection relationships, better circuit stability, lower costs and energy saving.

[0163] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0164] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

[0165]

[0166]

Claims

1. A power supply circuit based on three-phase electricity, characterized in that: The power supply circuit includes an information acquisition module and a power supply circuit unit, wherein the power supply circuit unit includes three circuit groups formed by three phases of A / B / C phases connected to three-phase electricity and a control center for controlling the working states of the three circuit groups; The circuit group includes an input rectifier module, an inductor, a capacitor, a switch and a controller thereof, and a transformer; one end of the inductor is used to connect to the live wire end of one phase of three-phase electricity, 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 live wire end or the neutral wire end of another phase, and the two output ends of the secondary winding of the transformer are output ends for providing electric energy for the circuit group, wherein the end corresponding to one end of the capacitor connected to the primary winding needs to be connected to an output half-wave rectifier module for performing half-wave rectification on the output of the circuit group; Wherein, the power supply circuit unit includes three circuit groups whose output ends corresponding to the three-phase electricity are connected in parallel; The maximum input voltage of the circuit group is V 入 With the maximum output voltage V 出 The ratio is V 入 :V 出 =0.3-7.6, when the output power is greater than 200W, the parameter range of the capacitor is 35nF-2.9μF, the inductance range of the primary winding of the transformer is 15μH-950μH; the ratio range of the primary winding / secondary winding of the transformer is R 原 :R 副 =1:5-5:

1.

2. The three-phase power supply circuit according to claim 1, characterized in that: The control center controls the duty cycle and frequency of the switches in the circuit group by transmitting control information to the switches; When the switch in the corresponding circuit group is in a closed state, the switch in the corresponding circuit group forms a loop with the input power supply of the phase connected and the inductor, and charges the inductor; the capacitor forms an LC oscillation loop with the switch and the inductor of the primary winding of the transformer, and the energy stored in the capacitor is transferred between the primary winding of the transformer and the capacitor; When the switch is in the off state, an LLC oscillation circuit is formed with the connected input power supply of this phase, the inductor, the capacitor and the primary winding of the transformer. The connected input power supply of this phase and the charged inductor charge the capacitor. At the same time, the charged inductor superimposes its own energy on the energy stored in the primary side of the transformer and induces electrical energy into the secondary winding through the current change of the primary side of the transformer.

3. The three-phase power supply circuit according to claim 1, characterized in that: The A / B / C three-phase controller is connected to the information acquisition module, and is used to generate first control information based on the phase information of the corresponding phase of the input power source acquired by the information acquisition module, and provide the first control information to the control center; the control center adjusts the first control information according to the overall requirements of the load for the output of the power circuit, and generates second control information including the switch duty cycle and frequency; and provides the second control information to the switch of the corresponding phase.

4. The three-phase power supply circuit according to claim 1, characterized in that: The circuit group realizes power factor tracking through inductance and switch cooperation, and also realizes dynamic adjustment of voltage increase and voltage decrease according to input / output voltage, current information and the requirements of connected load for output voltage.

5. The three-phase power supply circuit according to claim 1, characterized in that: The output ends of the three circuit groups corresponding to the three-phase electricity included in the power supply circuit unit are connected in parallel, including: the output ends of the three circuit groups corresponding to the three-phase electricity are connected in parallel and then connected to the output capacitors, or the output ends of the three circuit groups are connected to the output capacitors respectively and then the output capacitors are connected in parallel. 6 . The power supply circuit based on three-phase electricity according to claim 1 , wherein the half-wave rectification module realizes half-wave rectification by means of a diode.

7. The three-phase power supply circuit according to any one of claims 1 to 5, characterized in that: The half-wave rectification module realizes half-wave rectification through a first switch and a first controller that controls the first switch.

8. The three-phase power supply circuit according to any one of claims 1 to 5, characterized in that: The transformer structure of the circuit group in the power supply circuit is copper foil or U-shaped metal sheet, and the winding method is parallel winding.

9. A method for realizing power factor tracking and voltage boost / voltage reduction dynamic adjustment based on a three-phase power supply circuit according to any one of claims 1 to 8, characterized in that: The method comprises: Step S1, obtaining the current actual input current, input voltage, output voltage, and output current values ​​at high frequency; Step S2, comparing the current actual output power obtained with the target output power required by the connected load; Step S3, adjusting the input current peak value at high frequency according to the comparison result between the current actual output power and the target output power; Step S4, determining the target input current value at high frequency according to the input current peak value and the current input phase information; Step S5, comparing the current actual input current value with the target input current value, and determining the duty cycle and frequency adjustment instruction information of the switch at high frequency according to the comparison result; Step S6, the switch of the power circuit executes the instruction information at a high frequency to control the charging and discharging time of the inductor in the power circuit so that the current actual input current value of the power circuit is as close as possible to the target input current value.

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