CN116846186A

CN116846186A - Power supply circuit and extended power supply circuit and PFC/boost/buck realization method thereof

Info

Publication number: CN116846186A
Application number: CN202310658624.1A
Authority: CN
Inventors: 苏昕; 毕硕威
Original assignee: Shenzhen Yineng Times Technology Co ltd
Current assignee: Shenzhen Yineng Times Technology Co ltd
Priority date: 2023-06-05
Filing date: 2023-06-05
Publication date: 2023-10-03
Also published as: CN117477900A

Abstract

The application discloses a power supply circuit, a first extended power supply circuit, a second extended power supply circuit and a third extended power supply circuit based on the power supply circuit for realizing PFC and boosting/reducing, wherein the power supply circuit comprises an information acquisition module, an inductor, a switch, a controller for controlling the working state of the switch, a capacitor, a transformer and an output half-wave rectification module; the power supply circuit controls the duty ratio and the frequency of the switch so as to control the charge and discharge time of the inductor, so that the power factor tracking can be realized, and meanwhile, the dynamic adjustment of the voltage boosting and the voltage reducing can be realized according to the input voltage and the output voltage requirement of the power supply circuit, and the load requirement can be met; compared with the prior art, the power circuit unit and the first, second and third extended power circuits thereof can simultaneously realize the functions of boosting, reducing voltage, tracking power factor and the like, use fewer components, effectively save cost, have good stability, and have low energy loss and high electric energy conversion rate.

Description

Power supply circuit and extended power supply circuit and PFC/boost/buck realization method thereof

Technical Field

The application relates to the technical field of power supply circuits, in particular to a power supply circuit technology under a larger power scene.

Background

In the prior art, a power module applied to a larger power (not below 200 watts) or a large power scene generally comprises a front stage circuit and a rear stage circuit, wherein the front stage generally adopts a Boost rectifier or various topological circuits equivalent to the Boost circuit to realize power factor tracking (also called PFC), and the mainstream PFC topological scheme is a three-phase three-wire three-level VIENNA (for example, the main PFC topological scheme also comprises two-way staggered parallel three-phase three-wire three-level VIENNA, a single-phase staggered three-phase three-wire three-level VIENNA, a totem pole topological circuit and a Boost circuit); the scheme of the post-stage DC-DC generally realizes voltage reduction/voltage stabilization through a circuit topology mode based on a full bridge or a half bridge.

The topology circuit for implementing PFC at the front stage of the power supply module in the prior art shown in fig. 1 is specifically a connection schematic diagram of a three-phase three-wire system three-level VIENNA circuit, and the topology circuit for implementing voltage stabilization/isolation of the power supply module at the rear stage of the power supply module in the prior art shown in fig. 2 is specifically a connection schematic diagram of two groups of interleaved series two-level full bridge LLC, and only fig. 1 and 2 can see that the power supply circuit in the prior art has many components, very complex circuit structure, and inevitably causes the problems of poor stability of the power supply circuit, etc.

In the prior art, PFC (Power Factor Correction, translation: power factor tracking) is realized by using a two-stage circuit, and the energy consumption of a power module product for realizing voltage reduction/voltage stabilization through DC/DC is higher: as an example, power modules with full load efficiency maintained between 95% and 95.5% are currently common in the market: the disclosure data of the charging module product with the number of R100030G1 describes that the full load efficiency is 95.35%, the English flying source product with the number of REG1K0100A2 is 95.5%, and the disclosure data describes that if the charging module product with the full load efficiency of 95.5% and the power of 30kW is taken as an example, the energy consumption generated per hour is (1-95.5%) 30kW 1 h=1.35 kWh, namely, about 1.35kWh of energy is wasted per hour.

Therefore, the power module in the prior art generally needs a front-back circuit to realize the conversion and transmission of power, has many components and complicated circuit connection, and has the problems of low conversion rate, high conversion rate cost, large energy loss, poor stability and the like.

Disclosure of Invention

The application aims to provide a power circuit and a first, a second and a third expansion power circuits based on the power circuit, which can solve the problems of low power circuit conversion rate, high electric energy conversion rate cost, poor stability and the like in the prior art.

The application provides a power supply circuit which comprises an information acquisition module, a power supply circuit unit and a controller, wherein the power supply circuit unit comprises an inductor, a switch, a capacitor, a transformer and an output half-wave rectification module;

one end of an input power supply for providing electric energy for the power supply circuit is connected with one end of the inductor, and the other end of the inductor is connected with one end of the capacitor and one end of the switch; the other end of the capacitor is connected with one end of a primary winding of the transformer; the other end of the switch and the other end of the primary winding of the transformer are connected with the other end of the input power supply and grounded; one output end of the secondary winding of the transformer is connected with the output half-wave rectification module, and the output end of the half-wave rectification module and the other output end of the secondary winding of the transformer are output ends for providing electric energy for a load by the power circuit unit;

the information acquisition module is used for acquiring information of an electric energy input end and/or an electric energy output end of the power supply circuit unit;

the controller is connected with the information acquisition module and the switch, and is used for generating instruction information for controlling the duty ratio and the frequency of the switch according to the information acquired by the information acquisition module and the output requirement of the load on the power circuit, and controlling the switch to execute the instruction information.

Preferably, the power supply circuitMaximum value of input voltage V _{Into (I)} And the maximum value V of the output voltage _{Out of} Is in the ratio of V _{Into (I)} :V _{Out of} When the output power is larger than 200W, the parameter range of the capacitor is 30nF-3 mu F, and the inductance range of the primary winding of the transformer is 10 mu H-1000 mu H; the proportion range of primary side winding to secondary side winding of the transformer is R _{Original source} :R _{Auxiliary pair} ＝1:5-5:1。

Preferably, the ratio of the maximum value of the input voltage to the maximum value of the output voltage of the power supply circuit is V _{Into (I)} :V _{Out of} When the output power is 200W-1000W, the inductance of the primary winding of the transformer ranges from 10 mu H to 1000 mu H, the parameter of the capacitor ranges from 100nF to 3 mu F, and the ratio range of the primary winding to the secondary winding of the transformer is R _{Original source} :R _{Auxiliary pair} ＝1:5-1:1。

Preferably, the ratio of the maximum value of the input voltage to the maximum value of the output voltage of the power supply circuit is V _{Into (I)} :V _{Out of} When the output power is 1000W-2000W, the primary side inductance of the transformer ranges from 30 mu H to 1000 mu H, the capacitance parameter ranges from 50nF to 3 mu F, and the primary side/secondary side winding ratio of the transformer ranges from R _{Original source} :R _{Auxiliary pair} ＝1:2-2:1。

Preferably, the ratio of the maximum value of the input voltage to the maximum value of the output voltage of the power supply circuit is V _{Into (I)} :V _{Out of} When the output power is 1000W-2000W, the primary side inductance of the transformer ranges from 50 mu H to 250 mu H, the capacitance parameter ranges from 200nF to 800nF, and the primary side/secondary side winding ratio of the transformer ranges from R _{Original source} :R _{Auxiliary pair} ＝2:1-5:1。

Preferably, the ratio of the maximum value of the input voltage to the maximum value of the output voltage of the power supply circuit is V _{Into (I)} :V _{Out of} When the output power is 2000W-10000W, the primary side inductance of the transformer ranges from 50 mu H to 250 mu H, the capacitance parameter ranges from 200nF to 800nF, and the primary side/secondary side winding ratio of the transformer ranges from R _{Original source} :R _{Auxiliary pair} ＝1:1-2:1。

Preferably, when the input power of the power supply circuit is ac, the power supply circuit further comprises an input rectifying module providing a dc input to the inductor.

Preferably, the input rectifying module of the power supply circuit is a full-wave rectifying circuit or a half-wave rectifying circuit.

Preferably, the output half-wave rectification module of the power supply circuit realizes half-wave rectification through a diode.

Preferably, the output half-wave rectification module of the power supply circuit realizes half-wave rectification through a fifth switch and a fifth controller for controlling the fifth switch.

Preferably, the fifth controller controls the switching mode of the fifth switch according to a mode in which the controller of the power supply circuit controls the switch to induce power to the secondary winding of the transformer.

Preferably, the switching of the power supply circuit is realized by a bi-directional switch, a switching assembly or a controllable switching device.

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

Preferably, the transformer in the power circuit is copper foil or U-shaped metal sheet, and the winding mode is parallel winding.

Preferably, the inductance of the power supply circuit is matched with the control of the controller on the working state of the switch, so that the power supply circuit can simultaneously realize power factor tracking and dynamic adjustment of rising/falling according to output requirements.

The application also provides a first expansion power supply circuit, which comprises the two power supply circuit units when the input power supply is alternating current, wherein the first expansion power supply circuit comprises a first power supply circuit unit, a second power supply circuit unit, a first information acquisition module for acquiring voltage/current information of the input end and the output end of the first expansion power supply circuit, a first diode and a second diode which are respectively connected with the first power supply circuit unit and the second power supply circuit unit, and a first control center which is connected with the first information acquisition module and used for controlling the working state of a switch in the first power supply circuit unit and the second power supply circuit unit.

Preferably, when the input power supplies input current to the first power supply circuit unit through the first diode, the first control center controls the switch of the second power supply circuit unit to be in an off state, and the first power supply circuit unit works normally;

When the input power supply inputs current to the second power supply circuit unit through the second diode, the first control center controls the switch of the first power supply circuit unit to be in an off state, and the second power supply circuit unit works normally.

Preferably, the power supply output terminal of the first power supply circuit is connected in series or parallel with the power supply output terminal of the second power supply circuit.

The application also provides a second extended power supply circuit, when the input power supply is alternating current, the second extended power supply circuit comprises the two power supply circuit units, namely a third power supply circuit unit and a fourth power supply circuit unit, a second information acquisition module for acquiring voltage/current information of the input end and the output end of the second extended power supply circuit, and a second control center connected with the second information acquisition module and used for controlling the working state of a switch in the third/fourth power supply circuit unit.

Preferably, an output terminal of the third power supply circuit unit for supplying power is connected in series or in parallel with an output terminal of the fourth power supply circuit unit for supplying power.

Preferably, when the input power supplies current to the third power supply circuit unit, the second control center controls the switch of the fourth power supply circuit unit to be in a closed state, and the third power supply circuit unit works normally;

When the input power supply inputs current to the fourth power supply circuit unit, the second control center controls the switch of the third power supply circuit unit to be in a closed state, and the fourth power supply circuit unit works normally.

The application also provides a third extended power supply circuit which comprises the second extended power supply circuit without the inductance in the third or fourth power supply circuit unit when the input power supply is alternating current.

The application also provides a method for simultaneously realizing power factor tracking and voltage boosting/reducing of the power supply circuit, wherein the power supply circuit is the power supply circuit, or the first extended power supply circuit, or the second extended power supply circuit, or the third extended power supply circuit, and the method comprises the following steps:

step S1, dynamically acquiring the current actual input current, input voltage, output voltage and output current value;

s2, comparing the obtained current actual output power with the target output power required by the access load;

step S3, dynamically determining a target input current value according to a comparison result of the current actual output power and the target output power;

S4, comparing the current actual input current value with the target input current value, and dynamically determining the duty ratio of a switch and frequency adjustment instruction information according to the comparison result;

and S5, executing the instruction information by a switch of the power supply circuit, and dynamically controlling the charge and discharge time of an inductor in the power supply circuit, so that the current actual input current value of the power supply circuit approaches the target input current value as much as possible.

Compared with the prior art, the power supply circuit comprises a power supply circuit unit consisting of an inductor, a switch, a capacitor, a transformer and an output half-wave rectification module, an information acquisition module for acquiring current/voltage information of the input end and the output end of the power supply circuit, and a controller for generating instruction information for controlling the duty ratio and the frequency of the switch and controlling the switch to execute the instruction information according to the information acquired by the information acquisition module and the output requirement of a load on the power supply circuit; when the switch is in a closed state, the switch, an input power supply and an inductor form a loop and charge the inductor, and at the moment, the capacitor, the switch and the primary winding inductor of the transformer are equivalent to form an LC oscillating loop; when the switch is in an off state, the input power supply, the inductor, the capacitor and the primary winding of the transformer are equivalent to form an LLC oscillation loop, the input power supply and the charged inductor charge the capacitor, electric energy is induced into the secondary winding through current change of the primary winding of the transformer, and the output end of the secondary winding is used as the output end of the power supply circuit for supplying the electric energy, so that electric energy transmission is realized. The method for simultaneously realizing power factor tracking and boosting/reducing according to output needs can further adjust the frequency and the duty ratio of a switch by adjusting the peak value of input current at high frequency, control the charge and discharge time of an inductor, realize the power factor tracking, and realize the dynamic adjustment of boosting and reducing according to the input voltage and the output voltage of the power circuit, and high-frequency isolation so as to meet the load needs; compared with the prior art, the power supply circuit can simultaneously realize the functions of boosting and reducing voltage, tracking power factor, isolating high frequency and the like, uses fewer components, can effectively save cost, has good stability, and has low energy loss and high electric energy conversion rate.

Drawings

FIG. 1 is a schematic diagram of a three-phase three-wire system three-level VIENNA circuit connection of a pre-stage PFC topology circuit of a prior art power supply module circuit;

FIG. 2 is a schematic diagram of two sets of interleaved series two-level full-bridge circuits connected in a post-stage DC-DC topology of a prior art power module circuit;

FIG. 3 is a schematic diagram showing the connection of a power circuit unit according to an embodiment of the present application;

FIG. 4 is a schematic diagram showing the connection of power circuit units according to another embodiment of the present application;

FIG. 5 is a schematic diagram of the connection of a first extended power circuit according to one embodiment of the present application;

FIG. 6 is a schematic diagram of the connection of a second extended power circuit according to one embodiment of the present application;

FIG. 7 is a schematic diagram of the connection of a third extended power circuit according to an embodiment of the present application;

FIG. 8 is a schematic diagram showing the connection of power circuit units according to another embodiment of the present application;

FIG. 9 is a schematic diagram showing the connection of power circuit units according to another embodiment of the present application;

fig. 10 is a flowchart of a method for implementing PFC and boost/buck simultaneously in a power supply circuit according to an embodiment of the present application.

Detailed Description

In order to make the technical solution of the present application better understood by those skilled in the art, the technical solution of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, shall fall within the scope of the present application.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Referring to fig. 1 and 2, the power supply circuit in the prior art is provided with a front stage circuit and a rear stage circuit, the front stage circuit in fig. 1 is used for performing power factor tracking (PFC)/boosting/rectifying and the like, the rear stage circuit in fig. 2 is used for performing voltage reduction/voltage stabilization and isolation of input and output, the whole power supply circuit comprises the front stage circuit and the rear stage circuit, the number of components of the front stage circuit and the rear stage circuit is large, and the circuit connection is complex; in the field of high-power supplies with power higher than 200 watts, commonly used front-stage PFC is Vienna and totem pole, and commonly used rear-stage PFC is LLC and phase-shifting full bridge. In the traditional power circuit technology, the input alternating current is rectified and boosted into direct current with fixed voltage by using a front-stage PFC circuit, and power factor tracking is completed in the boosting process. The direct current of the fixed voltage generated by the front stage is dynamically boosted and reduced to the voltage appointed by the product user through the DC-DC circuit of the rear stage. Because the current in the power supply circuit needs to flow through the PFC/DC-DC two-stage circuit, a large amount of energy loss is generated on components, the power supply circuit disclosed by the application can realize the capacities of the original front-stage PFC and the back-stage DC-DC by a single circuit, realizes power factor tracking by using very few components, and dynamically boosts/reduces the voltage to the voltage required by a load, and simultaneously realizes input/output isolation.

The power supply circuit realizes the conversion of electric energy, namely the conversion of electric energy under different currents, voltages and powers, and can particularly comprise, but is not limited to, an inverter, a converter, a frequency converter, a power supply charging module and the like.

Referring to fig. 3, the application provides a power circuit, which comprises an information acquisition module, a power circuit unit and a controller, wherein the power circuit unit comprises an inductor, a switch, a capacitor, a transformer and an output half-wave rectification module.

One end of an input power supply for providing electric energy for the power supply circuit is connected with one end of the inductor, and the other end of the inductor is connected with one end of the capacitor and one end of the switch; the other end of the capacitor is connected with one end of a primary winding of the transformer; the other end of the switch and the other end of the primary winding of the transformer are connected with the other end of the input power supply and grounded; one output end of the secondary winding of the transformer is connected with the output half-wave rectification module, and the output end of the half-wave rectification module and the other output end of the secondary winding of the transformer are output ends of the power supply circuit unit for outputting electric energy.

The information acquisition module is used for acquiring voltage and current information of the input end and the output end of the power circuit unit;

the controller is connected with the information acquisition module and the switch and is used for generating instruction information for controlling the duty ratio and the frequency of the switch according to the information acquired by the information acquisition module and the output requirement of the load on the power supply circuit.

Specifically, the working process of the power supply circuit is as follows:

when the switch is in a closed state, the switch, an input power supply and an inductor form a loop and charge the inductor; the capacitor, the switch and the primary winding inductor of the transformer form an LC oscillating loop; when the switch is in an off state, the input power supply, the inductor, the capacitor and the primary winding of the transformer form an LLC oscillation loop, the input power supply and the charged inductor charge the capacitor, and simultaneously, energy is induced to the secondary side of the transformer through the primary winding of the transformer; the inductance of the power circuit unit is matched with the control of the controller on the working state of the switch, so that the power circuit can simultaneously realize power factor tracking and dynamic adjustment of rising/falling according to output requirements.

Referring to fig. 3, there is shown a schematic diagram of the connection of a power circuit unit of the present application, the power circuit unit comprising: the device comprises an inductor L, a switch K, a capacitor C, a transformer T and an output half-wave rectification module; one end of an input power supply is connected with one end of the inductor L, and the other end of the inductor L is connected with one end of the capacitor C and one end of the switch K; the other end of the capacitor C is connected with one end of a primary winding of the transformer T; the other end of the switch K is connected with the other end of the primary winding of the transformer and grounded; two output ends of the secondary winding of the transformer are output ends of the power supply circuit unit for supplying electric energy, and one end of the output ends is connected with the half-wave rectification module; the controller is used for controlling the time proportion of the switch K in a closed state in the period time according to the electric energy requirement output by the power circuit, further, the period time can be changed, namely the period time can be changed, the controller generates switch control information according to the voltage and current information of the input end and the output end acquired by the information acquisition module and the requirement of the load on the output of the power circuit unit, and the frequency and the duty ratio of the switch K for opening and closing are controlled.

The working principle of the power supply circuit is as follows:

specifically, according to the information acquired by the information acquisition module and the output requirement of the load on the power circuit, generating instruction information for controlling the duty ratio and the frequency of the switch; when the switch K 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, the switch K and the primary winding inductance of the transformer T form an LC oscillating loop; when the switch K is in an off state, the input power supply, the inductor L, the capacitor C and the primary winding inductor of the transformer T form an LLC oscillation loop, the input power supply and the charged inductor L charge the capacitor C, and electric energy is induced to the secondary side of the transformer through current change of the primary side of the transformer.

The power supply circuit disclosed in this embodiment discharges the capacitor C and the primary winding of the transformer T after charging the inductor L by controlling the working state of the switch K, so that the primary winding of the transformer T obtains energy and senses the energy to the secondary winding of the transformer T, and further outputs the electric energy. The frequency and the duty ratio of the switch K are controlled to control the charge/discharge time of the inductor L and the charge/discharge time of the primary winding inductor of the transformer and further control the electric energy output by the secondary winding of the transformer.

Specifically, a loop formed by the power supply circuit disclosed in the embodiment in the working process includes: loop (1) [ input power supply+inductance l+capacitance c+transformer T ], loop (2) [ input power supply+inductance l+switch K ], loop (3) [ capacitance c+transformer t+switch K ].

Further, the detailed working procedure of the power supply circuit disclosed in this embodiment is as follows: when the switch K is closed, the input power supply charges the inductor L, the inductor L stores energy, the switch K is disconnected, the current at the two ends of the inductor L cannot be suddenly changed, a high voltage is generated, the electric energy is transmitted through a new loop (1) formed after the switch K is disconnected, the inductor L and the power supply charge the capacitor C, and when the input power supply voltage regularly changes, the voltage of the charged capacitor C changes along with the current input voltage. In particular, when the ac input voltage is close to 0 v, the voltage across capacitor C is also close to 0 v. The energy stored in the inductor L and the primary side of the transformer T is induced to the secondary side of the transformer by the primary side of the transformer, and at this time, the voltage of the input power supply plus the voltage of the inductor L is equal to the voltage of the capacitor C plus the primary side winding of the transformer T, namely: v (V) _{Input power supply} +V _L ＝V _C +V _{T primary} The method comprises the steps of carrying out a first treatment on the surface of the The transformer T inducts the electric energy to a secondary winding thereof, and the secondary winding outputs the electric energy to an electric energy supply output end of the power circuit unit through the half-wave rectification module to supply the electric energy to a load; when the switch K is switched from an off state to an on state, a loop formed by the power circuit sequentially comprises the following specific working processes: the power supply circuit charges the inductor L through the loop (2), charges the primary winding of the transformer T through the capacitor C of the loop (3), the voltage of the capacitor C follows the current voltage of the input power supply and charges the primary winding of the transformer T, and at the moment, the capacitor C and the primary winding of the transformer T are equivalent to form an LC resonant loop, so that the electric energy of the loop is kept; meanwhile, after the switch K is in a closed state, the inductance L is charged through the input power of the (2) th loop, and the inductance L stores energy next time.

When the electric energy provided by the input power supply to the power supply circuit unit is a periodically fluctuating voltage, such as a periodic sine wave, a square wave, a triangular wave, a trapezoidal wave and the like, the power supply circuit can simultaneously realize power factor tracking and dynamic adjustment of boosting and/or reducing voltage which meets corresponding output requirements.

Specifically, when the electric energy provided by the input power supply to the power supply circuit unit is periodically fluctuating voltage, the inductance of the power supply circuit is matched with the working state of the switch, so that the power supply circuit realizes the working process of power factor tracking:

when the input power supply is periodically ac input, the voltage period T ' of the input inductor after the input power supply is rectified is set to a first time interval [ if the input power supply is dc, the voltage period T ' of the input power supply is directly set to the first time interval without rectification ], and the input voltage is continuously changed in the first time interval T '. The time period interval corresponding to the switching frequency of the controller control switch K is set as a second time interval T' according to the characteristic of the inductor that the parameter characteristic of the inductor does not allow current abrupt change; under the condition that the second time interval T 'is smaller than the voltage period T' of the input inductor by a plurality of magnitudes, the switching K is completed hundreds or thousands of times within the range of the voltage period T ', namely, in the process that the input power supply provides the change from the trough to the crest in the voltage period T', the switching frequency is higher, for the working process of the working state control power supply circuit unit through the switching K, the voltage of the input power supply is not changed greatly locally, basically the voltage is not changed, namely, the input power supply voltage corresponding to the switching K before and after one time is regarded as unchanged, simultaneously, under the condition that the first time interval T 'comprises a plurality of second time intervals T', namely, the input voltage is obviously changed, the inductor L performs a plurality of charging and discharging processes through the control of the switching K, namely, the inductor L has completed the circuit (1) in the working process, the input power supply +inductor L+the capacitor C+the transformer T, the circuit (2) [ input power supply +inductor L+the switch ] and the switching K ] can be transmitted to the power supply smoothly through the transformer C+the circuit, and the current can be transmitted to the power supply smoothly even though the input power supply voltage is not changed to the transformer C+the transformer, and the power supply is smoothly, the current is transmitted to the power supply is supplied to the circuit, and the power supply is smoothly, and the power is supplied to the power supply is smoothly and the power supply has a low-level, and the power supply voltage is smoothly has a certain cycle, and the power is smoothly input to the power supply voltage is smoothly even though the voltage is changed.

In the embodiment, the inductor can realize power factor tracking in the power supply circuit, which means that the inductor can fully utilize partial electric energy with very low voltage input by the input power supply, and the power factor of the power supply circuit can exceed 99% under the condition of outputting rated power or more than half-load by reasonably setting the values of T 'and T' through the method.

Specifically, the power supply circuit of the application can realize the dynamic adjustment of the voltage boosting and the voltage reducing according to the specific conditions of the input voltage and the output voltage required by the load of the power supply circuit and the working state of the switch K, and the specific dynamic adjustment of the voltage boosting/reducing process is as follows:

when the voltage provided by the power circuit is insufficient and cannot meet the load requirement and needs to be boosted, the controller generates control information for increasing the duty ratio of the switch K or reducing the working frequency of the switch K, namely increasing the charging time of the inductor L and the primary winding of the transformer, and when the inductor L and the primary winding of the transformer are disconnected, more electric energy is induced to the secondary winding of the transformer T so as to realize boosting. Further, if the voltage provided by the power circuit unit is higher, and voltage needs to be reduced, the controller generates control information for reducing the duty ratio of the switch K and/or increasing the working frequency of the switch K, and reduces the charging time of the inductor L and the primary winding of the transformer, so that the electric energy transmitted to the secondary winding of the transformer is reduced, and voltage reduction is realized.

Here, when the period interval t″ corresponding to the operating frequency of the switch K is higher than the period T 'of the input power supply voltage by several orders of magnitude, that is, t″ is greater than T', the frequency and the duty ratio of the switch K are adjusted, and the charge and discharge time of the inductor is further adjusted to achieve voltage boosting/reducing, specifically, the magnitude of the period T 'of the input power supply voltage can be set according to the specific condition of the input power supply, and further, if the input power supply is an alternating current with periodically changed voltage, for example, a power frequency sine wave alternating current, the frequency is 50HZ, the corresponding period is 20ms, and after passing through the rectifier bridge, the formed pulsating direct current is corresponding to T' =10 ms; if the input power supply is voltage variation and has no obvious periodicity, the value of T' can be set in a variation period similar to that of sine wave alternating current, and the specific setting mode only needs to meet the requirements described above, so that the scheme of the application can be realized.

In this embodiment, "step up" and "step down" refer to the supply circuit providing the desired voltage, current, and power to the load according to the load's requirements. Meanwhile, in order to ensure that the power required by the load is provided, the power supply circuit has the advantages that the load is required for the output voltage of the circuit, the battery load, the resistance load, the power grid load and the like, and part of the load has small output voltage change and large current change. The output voltage of the partial load changes greatly, the current changes linearly with the voltage, and the partial load has requirements on the output voltage waveform.

Depending on the load requirements, the voltage provided by the power supply circuit may be higher or lower than the input voltage maximum. Also, as the operating time changes, the output voltage of the power supply circuit may change. The application relates to dynamic boosting, which means that the output voltage is higher than the maximum value of the input voltage and is dynamically adjusted and changed according to the load requirement. "dynamic buck" refers to an output voltage below the input voltage maximum and dynamically adjusting changes according to load requirements.

In order to ensure the advantages of good stability, low cost and the like of the power circuit, the power conversion rate is higher, and the parameters of components in the power circuit are required to be selected and determined.

Determining principle of component parameters in a power supply circuit: the determination of specific component parameters is related to the input voltage, the output voltage and the output power of the power supply circuit. The input voltage maximum, the output voltage maximum, and the output power of the power supply circuit are first determined, where in the case of alternating current, the voltage maximum refers to its effective value and in the case of direct current, the voltage maximum refers to the maximum of the input/output voltage range. And determining capacitance parameters, inductance values of primary/secondary windings of the transformer, primary/secondary winding ratios, switching operating frequency ranges and the like in the power circuit according to the maximum value of the input voltage, the maximum value ratio of the output voltage and the output power of the power circuit unit.

Specifically, in practice, the inductance of the power circuit and the primary/secondary inductance parameters of the transformer need to be considered when determining:

when the parameters such as the working frequency/duty ratio of the switch, the primary side inductance of the transformer, the inductance of the inductor and the like are not changed, and the input voltage is increased, the primary side winding inductor of the transformer can store more energy during the switch on period, and the energy stored by the primary side winding inductor of the transformer is induced to the secondary side winding of the transformer during the switch off period, so that the output power of the power circuit unit can be increased; when the input voltage decreases, the output power of the power supply circuit unit can be reduced.

When the input voltage maximum value, the inductance of the inductor, the switching frequency/duty ratio and other parameters are not changed, and the primary side inductance of the transformer is reduced, more energy can be stored in the primary side inductance of the transformer during the switch on period, and the energy stored in the primary side inductance of the transformer is induced to the secondary side winding of the transformer during the switch off period, so that the output power of the power circuit unit can be increased; correspondingly, when the inductance of the primary winding of the transformer is increased, the output power of the power circuit unit can be reduced; in the process of determining the inductance of the primary winding of the transformer, consideration is also needed, and when the energy stored in the primary winding of the transformer is too much, the transformer may be saturated, so that the electric energy conversion efficiency is reduced.

In practice, the conversion efficiency of a circuit can be affected by changing the number of turns ratio of primary side/secondary side windings of the transformer; specifically, when the input voltage, the switching frequency/duty ratio, the load resistance value, the primary winding inductance of the transformer, the inductance of the inductor and the like are determined, the number of turns of the secondary winding is increased or the number of turns of the primary winding is reduced, namely the ratio of the primary winding to the secondary winding is reduced, so that the output voltage can be increased; correspondingly, the output voltage can be reduced by reducing the number of turns of the secondary winding or increasing the number of turns of the primary winding, namely increasing the primary/secondary winding proportion of the transformer; the parameters of the transformer are determined through the specific scene and the mode, so that the conversion efficiency of the power circuit unit can be effectively improved.

In practice, when the input voltage, the working frequency/duty ratio of the switch, the inductance of the primary winding of the transformer and the like are determined, the inductance of the inductor is reduced, more energy can be stored in the inductor during the on period of the switch, the primary winding of the transformer is charged by the energy stored in the inductor during the off period of the switch, and then the primary winding of the transformer induces the energy to the secondary winding of the transformer, so that the output power of the power circuit unit can be increased; when the inductance of the inductor increases, the output power of the power supply circuit unit can be reduced.

The frequency range of the switch is determined taking into account: when the switching frequency is reduced under the condition that parameters of other components in the power supply circuit are unchanged, the energy storage time t for switching on the switch in a single period is prolonged, and the frequency f is reduced; during the closing of the switch, the energy stored in the inductor, the primary side of the transformer, increases and the output power of the power supply circuit unit increases. Accordingly, when the switching frequency is increased, the output power of the power supply circuit is reduced. In addition, as the switching frequency increases, switching losses occur at the switching on and off moments of the switch, increasing the switching frequency and also increasing the switching losses. Here, the conversion efficiency of the transformer needs to be considered, and the corresponding inductance is different and the conversion efficiency is different under different frequencies of different magnetic cores. Too low a frequency, for example, below 30K, may lead to saturation of the transformer, causing a decrease in conversion efficiency; too high a frequency, for example, above 500K, may cause a large change in the inductance of the transformer, reducing the conversion efficiency.

The process of determining the parameters of the capacitor, as previously described, stores energy during the off-period of the switch, and during the on-period of the switch, the capacitor resonates with the primary winding of the transformer, transferring the stored energy to the primary winding of the transformer. The capacity value of the capacitor is too small, so that the energy stored on the capacitor is insufficient during the working period, the output power of the power circuit unit is reduced, and the conversion efficiency is further reduced; when the input voltage is alternating current, the voltage of the capacitor cannot follow the change of the input voltage of the alternating current, so that the calculation is difficult in the power factor tracking process, and the electric energy conversion efficiency is reduced.

From the above analysis, it is known that the components and their connection relationships included in the power supply circuit belong to a whole, the parameter settings of the components have relevance, and the parameter settings of all the components have integrity. In practice, the inductance of the inductor is designed according to the condition of the input voltage connected to the power supply circuit, the requirement of the connected load on the output voltage/output power, and the detailed parameter selection principle, and meanwhile, the material/cost of the transformer/inductor and the saturation condition of the transformer/inductor caused by the output power are considered, so that the balance of the parameters of each component in the whole power supply circuit can be achieved. The parameters such as inductance, primary winding inductance of the transformer, switching frequency, capacitance and the like in the power circuit are required to be selected in an independent setting range, and the coordination of the parameters of all components is required to be considered integrally according to the logical relation of parameter setting among the components, so that the power circuit has better electric energy conversion rate on the basis of ensuring good performance.

In one preferred embodiment, the power supply circuit inputs a voltage maximum value V _{Into (I)} And the maximum value V of the output voltage _{Out of} Is in the ratio of V _{Into (I)} :V _{Out of} When the output power is larger than 200W, the parameter range of the capacitor is 30nF-3 mu F, and the inductance range of the primary winding of the transformer is 10 mu H-1000 mu H; the proportion range of primary side winding to secondary side winding of the transformer is R _{Original source} :R _{Auxiliary pair} ＝1:5-5:1。

Specifically, when the output power of the power supply circuit is greater than 200W and the ratio of the maximum value of the input voltage to the maximum value of the output voltage is 0.2-8.0, according to the above parameter selection rule, when the parameter of the capacitor is smaller than 30nF, the voltage at both ends of the capacitor rises too fast in the turn-off period of the switch, so that the voltage at both ends of the switch rises too fast, the switch may be damaged, or a switch with higher withstand voltage must be used, and the cost of the switch is increased; meanwhile, under a high-power scene, when the capacitance parameter is smaller than 30nF, the energy stored in the capacitor of the power supply circuit is insufficient to support the energy released to the primary inductor of the transformer in the switch-on period in the switch-off period, so that the electric energy conversion efficiency is reduced. When the capacitance parameter is larger than 3 mu F, the current of the primary winding inductance of the transformer rises too fast during the switch conduction period, and at the moment of switch disconnection, the voltage peak caused by the leakage inductance of the transformer is too high, so that the voltage withstand requirement on the switch is higher, and the cost of the switch is increased; under the scene of alternating current input, when the capacitance parameter of the power supply circuit is larger than 3 mu F, excessive energy is stored in the capacitor, and when the input voltage is close to the zero point of a sine wave, the voltage at two ends of the capacitor is obviously higher than the input voltage. It may occur that when the voltage charged to the inductor of the power supply circuit is close to 0V, the voltage charged to the primary inductor of the transformer is greater than 0V, resulting in a decrease in power factor tracking efficiency. When the inductance of the primary winding of the transformer is smaller than 10 mu H, parameters of the transformer are difficult to balance, for example, the transformer is easy to saturate due to too few turns, and the effect of carrying enough power is poor; or the number of turns is enough, but the magnetic core air gap is too large, so that the magnetic leakage is serious, and the efficiency is reduced; when the primary side inductance of the transformer is larger than 1000 mu H, the energy storage period of the switch is conducted, the energy stored by the primary side inductance of the transformer is reduced, enough power can be carried by reducing the working frequency of the switch, but under the condition that the working frequency of the switch is too low, the electric energy conversion rate of the transformer is lower, and the transformer is easy to saturate. When the primary side/secondary side winding ratio of the transformer is smaller than 1:5, the leakage inductance of the secondary side winding of the transformer is easily caused to be too large due to the manufacturing process problem of the transformer, and when the switch is conducted, the leakage inductance of the secondary side winding causes larger oscillation of current of the switch, so that the efficiency is obviously reduced; when the primary side/secondary side winding ratio of the transformer is larger than 5:1, the leakage inductance of the primary side winding of the transformer is easily caused to be too large due to the manufacturing process problem of the transformer, and the leakage inductance of the primary side winding causes larger voltage oscillation at two ends of the switch at the moment of switching off the switch, so that the voltage-withstanding requirement on the switch is higher, and the cost of the switch is increased.

Specifically, in this embodiment, according to the above parameter selection principle, the parameters of the inductor in the power circuit are further determined, and since the electric energy is dynamically distributed between the inductor and the primary winding of the transformer according to the magnitude relation between the inductance value and the inductance value of the primary winding of the transformer during the operation of the power circuit, the inductance parameters need to have a relatively wide range, specifically 1 μh-10mH. When the inductance energy storage is more involved in more energy transfer, the parameter value can be set smaller, and the parameter range can be set to be 1 mu H-100 mu H; when the energy transmission is not participated or the energy transmission is less, the parameter value can be set larger, and the parameter range can be set to be 2mH-10mH.

Further, the following situations need to be considered when determining the specific value of the inductance parameter:

if the inductance of the inductor is selected to be near the inductance of the primary winding of the transformer, by way of example and not limitation: the inductance of the inductor and the inductance of the primary winding of the transformer are both set at 10 mu H-30 mu H, so that the energy stored by the primary winding of the transformer and the energy stored by the inductor are consistent in the energy storage period of switch conduction, and the advantage of the method is that the inductor shares the energy transmission task, and the inductor and the primary winding of the transformer balance heating points; meanwhile, requirements are put forward on the magnetic core materials of the inductor, the loss of the selected magnetic core in the energy storage and transmission processes needs to be carefully tested, the inductor saturation is avoided, and the inductor cost can be possibly increased.

If the inductance of the inductor is much greater than the inductance of the primary winding of the transformer, by way of example and not limitation: the inductance of the inductor is set at 800 mu H-1000 mu H, the inductance of the transformer is designed at 10 mu H, and the primary side of the transformer is mainly used for storing energy in an energy storage period.

The inductance of the inductor is set to be much lower than the inductance of the primary winding of the transformer, by way of example and not limitation: the inductance of the inductor is set at 10 muh and the inductance of the transformer is set at 1000 muh, which can result in the inductance storing energy far beyond the primary side of the transformer during energy storage. The inductance of the inductor and the inductance of the primary winding of the transformer are set to be larger, and the method is not limited: the inductance of the inductor is set at 100 mu-1000 mu H, and the inductance of the transformer is set at 100 mu-1000 mu H, which results in that the switching frequency must be set in a very low range to output power above 200W, and saturation of the transformer and the inductor is easy to cause, and very high requirements are set for parameters of the transformer and the inductor. In practice, the power supply circuit unit of the scheme has lower electric energy conversion efficiency.

Specifically, in this embodiment, the operating frequency of the switch is related to a variety of parameters. Under the condition that parameters such as the primary winding inductance of the transformer, the inductance of the inductor, the switching duty ratio, the input voltage, the load and the like are unchanged. The working frequency of the switch is reduced, and the output power of the power circuit unit is improved; increasing the operating frequency of the switch decreases the output frequency of the power circuit unit. It should be noted that too low a switching frequency, which is prone to saturation of the inductor and the transformer, will result in increased switching losses. Specifically, the switching frequency needs to be dynamically adjusted in real time according to the fluctuation condition of the input voltage and the dynamic requirement of the output voltage.

Further, in the process of dynamically boosting and reducing voltage according to output requirements of the power supply circuit, the values of the duty ratio and the frequency of the switch are required to be calculated and adjusted in real time, and in the process of realizing power factor tracking of the power supply circuit, the duty ratio and the frequency of the switch are adjusted so that the actual input current approaches the target input current which is synchronous with the input voltage and appears as regular change of the input voltage in real time, so that the working frequency range of the switch is required to be dynamically adjusted while the power factor tracking is required to be satisfied, and in particular, the range is about 30K-500K.

In summary, when the output power of the power supply circuit is greater than 200W, the ratio of the maximum value of the input voltage to the maximum value of the output voltage is 0.2-8, the parameter of the capacitor is set to be 30nF-3 mu F, the primary side inductance of the transformer is 10 mu H-1000 mu H, the inductance parameter range is 1 mu H-10mH, the primary side/secondary side winding ratio of the transformer is 1:5-5:1, the electric energy conversion rate of the power supply circuit can reach more than 96%, the electric energy conversion rate can reach more than 98% in certain specific scenes, compared with the prior art, the electric energy conversion rate is higher, meanwhile, the power supply circuit only uses few components, the ultrahigh electric energy conversion rate is realized under the condition of lower cost, and dynamic boosting and reducing can be realized according to the requirement of a load.

In one preferred embodiment, the ratio of the maximum value of the input voltage to the maximum value of the output voltage in the power supply circuit is V _{Into (I)} :V _{Out of} When the output power is 200W-1000W, the inductance of the primary winding of the transformer ranges from 10 mu H to 1000 mu H, theThe parameter range of the capacitor is 100nF-3 mu F, and the proportion range of the primary side winding and the secondary side winding of the transformer is R _{Original source} :R _{Auxiliary pair} ＝1:5-1:1。

Specifically, the embodiment provides a parameter range of the ratio of the corresponding capacitor, the primary winding of the transformer and the primary and secondary windings of the transformer in the components of the power circuit unit when the output power of the power circuit unit is 200W-1000W and the ratio of the calculated value of the input voltage to the calculated value of the output voltage is 0.2-1.0. According to the parameter determination principle and process, under the condition that the specific input voltage maximum value, the specific output voltage maximum value and the specific output power are determined, the specific parameters of the corresponding components are selected and determined within the parameter range of the corresponding components provided by the embodiment so as to meet the power factor tracking, and the dynamic adjustment of the voltage boosting and the voltage reducing required by the output end is realized, the electric energy conversion rate can reach more than 98%, the specific parameter experimental data and the test result are shown in the examples 1-4 in the table 1, and under the condition that the power circuit components have the same functions and the same electric energy conversion rate as those of the prior art, the power circuit components are obviously fewer than those of the circuit in the prior art, the energy loss is fewer, the cost is lower, and the circuit stability is stronger.

By way of example and not limitation, when the maximum input voltage of the power supply circuit is 50V, the maximum output voltage is about 250V, and the output power is 200W, the inductance sensing parameter is designed to be about 10 μ -1mH, the primary winding sensing parameter of the transformer is set to be about 10 μ -1mH, the capacitance parameter is set to be about 500nF-3000nF, and the primary/secondary winding ratio of the transformer is set to be about 1:2-1:5, at this time, the corresponding electric energy conversion rate is 97% or more, according to the above-described parameter design principle.

Specifically, in this embodiment, the inductance of the primary winding of the transformer is set to be 10 μh, or the inductance of the inductor is set to be about 10 μh, because the energy stored in the inductor and the energy stored in the primary winding of the transformer are low each time in the 50V input voltage, so that the primary winding of the transformer and the inductor store enough energy in the energy storage period, and the power supply circuit unit provides enough power for the output terminal or the connected load. However, if the inductance of the primary winding of the transformer is continuously reduced, or the inductance of the inductor is continuously reduced, the exciting current of the transformer is obviously increased, so that the conversion efficiency is obviously reduced.

In this embodiment, a transformer primary/secondary winding inductance ratio in the range of about 1:2-1:5 is employed. Since the maximum input voltage is only 50V, if a 1:1 transformer is adopted, the duty ratio of the switch operation needs to be increased to increase the output voltage. The required output voltage is 300V, and the duty ratio is increased to more than 70%, so that the output voltage of about 300V can be obtained, and the loss is reduced too much in the on-state of the switch, so that the conversion efficiency of the power supply circuit is low. The booster transformer with the primary side/secondary side winding inductance ratio range of 1:2-1:5 is adopted, so that the duty ratio of a switch can be effectively reduced, and the electric energy conversion efficiency is improved.

Because the input voltage is relatively low, the capacitance needs to be relatively large, so that enough energy can be stored in the primary winding of the transformer in the energy storage period. If the capacitance parameter is set below 500nF, when the output voltage changes dynamically, the situation that the energy stored in the capacitor is insufficient and the efficiency is reduced occurs at part of the power points. If the capacitance is set to 3000nF or more, it is observed that a large voltage spike is generated during the switching off of the switch, and a switch with better withstand voltage is required, which increases the cost.

In practice, the type of the switch element is selected, the switch element is also related to the setting of the working frequency of the switch, the common silicon-based MOS tube is limited to 150K in the highest frequency proposal; the highest frequency of the silicon carbide MOS tube is recommended to be limited to 500K; IGBT switching tube, highest frequency suggestion limit 40K; the highest frequency of gallium nitride MOS tube is limited to 800K. The switch of this embodiment is a general withstand voltage 150V high frequency switch on the market, for example, a high frequency switch with model number NCEP15T14, and the corresponding switching frequency range is: 50K-200K.

When the maximum value of the input voltage is 300V, the maximum value of the output voltage is about 300V, and the output power is 1000W, the inductance of the primary winding of the transformer is set to be about 60 mu H-1mH, the capacitance parameter is set to be about 100nF-500nF, the primary winding/secondary winding ratio of the transformer is set to be about 1:1, and the electric energy conversion rate of the corresponding power circuit is more than 98 percent.

Specifically, by way of example and not limitation, the embodiment may be applied in the solar photovoltaic field, where the input is 300V dc, the output is about 300V ac, the output power of the power circuit unit is 1000W, the maximum value of the input voltage and the maximum value of the output voltage are about 1:1, the inductance and the inductance of the primary winding of the transformer are selected to be relatively large, for example, the inductance of the primary winding of the transformer is set to be 60 μh, and the inductance is set to be 1mH. Since the ratio of the maximum value of the input voltage to the maximum value of the output voltage is 1, the primary side/secondary side inductance of the transformer used is about 1:1. Under the condition that the primary side/secondary side ratio of the transformer is close, the transformer processing technology can save cost, and leakage inductance is easy to control.

Under the application scene of the embodiment, a capacitor smaller than 100nF is selected, and the capacitor can possibly appear in an energy storage period when a switch is closed, and can not provide enough energy for a primary winding of a transformer, so that the conversion efficiency of a power circuit unit is reduced; the capacitor with the capacitance larger than 500nF is selected, when the primary winding inductance of the transformer is charged in the energy storage period of the switch closing, the charging current is easy to be large, and when the switch is opened, the primary leakage inductance of the transformer generates a voltage spike, so that a switch with higher withstand voltage is required to be selected, and the cost is increased.

In this embodiment, by way of example and not limitation, when the maximum input voltage is 300V, the maximum output voltage is about 300V, and the output power is 1000W, the primary winding of the transformer is set to about 60 μh-1mH, the capacitance parameter is set to about 100nF-500nF, and the primary/secondary winding ratio of the transformer is set to about 1:1, and the corresponding power conversion rate is at least 98% according to the above-described parameter design principle.

In this embodiment, for example, but not limited to, the embodiment can be applied in the solar photovoltaic field, the input is 300V dc, the output is about 300V ac, the output power of the power circuit unit is 1000W, the maximum value of the input voltage and the maximum value of the output voltage are about 1:1, and the inductance of the primary winding of the transformer are selected to be relatively larger. Less inductance will result in a decrease in power conversion efficiency. In practice, the inductance of the primary winding of the transformer is set to be 60 mu H, and the inductance is set to be 1mH, so that the electric energy conversion efficiency of the power supply circuit can reach 97.5% or more.

At the same time, the energy storage of the energy storage cycle may be selectively divided between the transformer and the inductor. The inductance is improved, the inductance of the transformer is reduced, the energy stored by the primary side of the transformer in the open-close energy storage period is more in duty ratio, and the inductance is less in duty ratio. The inductance is reduced, the inductance of the transformer is improved, the energy stored by the primary side of the transformer in the closed energy storage period of the open light pipe is smaller in proportion, and the inductance is larger in proportion.

Under the application scene of the embodiment, the capacitance parameter is about 100nF-500 nF; in practice, the capacitor less than 100nF has too little energy in the capacitor in the energy storage period of the switch closing, and cannot provide enough energy for the primary winding of the transformer, so that the electric energy conversion efficiency of the power supply circuit is reduced; the capacitor with the capacitance larger than 500nF stores too much energy in the energy storage period of the switch closing, charges the primary winding inductance of the transformer, easily causes large charging current, and at the moment of switch opening, the primary leakage inductance of the transformer generates a voltage spike, so that a switch with higher withstand voltage needs to be selected, and the cost is increased.

In this embodiment, since the ratio of the maximum value of the input voltage to the maximum value of the output voltage is 1, the primary/secondary inductance of the transformer used is about 1:1. Under the condition that the primary side/secondary side ratio of the transformer is close, the transformer processing technology can save cost, and leakage inductance is easy to control.

In one preferred embodiment, the ratio of the maximum value of the input voltage to the maximum value of the output voltage in the power supply circuit is V _{Into (I)} :V _{Out of} When the output power is 1000W-2000W, the primary side inductance of the transformer ranges from 30 mu H to 1000 mu H, the capacitance parameter ranges from 50nF to 3 mu F, and the primary side/secondary side winding ratio of the transformer ranges from R _{Original source} :R _{Auxiliary pair} ＝1:2-2:1。

Specifically, the embodiment provides a parameter range of the output power 1000W-2000W of the power circuit unit, and when the ratio of the calculated value of the input voltage to the calculated value of the output voltage is 0.5-1.5, the corresponding capacitor, primary winding of the transformer and primary and secondary winding ratio of the transformer in the components of the power circuit unit. According to the parameter determination principle and process, under the condition that the specific input voltage maximum value, the specific output voltage maximum value and the specific output power are determined, the specific parameters of the corresponding components are selected and determined within the parameter range of the corresponding components provided by the embodiment so as to meet the requirements of power factor tracking, and the dynamic adjustment of voltage boosting and voltage reducing according to the requirements of an output end, the electric energy conversion rate can reach more than 97%, even more than 98%, the specific parameter experimental data and test results are shown in the embodiments 5-7 in the table 1, and compared with the prior art, the power circuit component is obviously less than the components of the circuit in the prior art, less in energy loss, lower in cost and higher in circuit stability.

By way of example and not limitation, the input voltage is 220V sine wave, namely the maximum value of the input voltage is about 311V, the maximum value of the output voltage is about 200V, and the output power is 2000W, under the above parameter design principle, the primary winding inductance range of the transformer is set to about 30 muh-1 mH, the capacitance parameter range is set to about 500nF-3000nF, the primary/secondary winding ratio of the transformer is set to about 2:1, the electric energy conversion rate of the power circuit can be up to more than 97%, and the power circuit has few components, small energy loss, higher stability and more energy conservation as compared with the prior art.

By way of example and not limitation, the input voltage is a 380V sine wave, i.e., the maximum value of the input voltage is about 540V, the maximum value of the output voltage is about 1000V, the ratio of the maximum value of the input voltage to the maximum value of the output voltage is about 0.5, and the output power is 1000W, and according to the above-mentioned parameter design principle, the inductance of the primary winding of the transformer is set to about 150 μh-1mH, the capacitance parameter is set to about 50nF-500nF, the ratio of the primary winding to the secondary winding of the transformer is set to about 1:2, and the corresponding electric energy conversion rate is at least 98%.

Specifically, in this embodiment, when the output voltage is 1000V, the output voltage is too high, and if a 1:1 transformer is used, the output voltage is induced to the primary side of the transformer, and the capacitor voltage is superimposed, so that the switch withstand voltage is too high, and the switch is damaged. When the transformer with the ratio of 1:2 is used, during the switch turn-off period, the primary side voltage is only 500V after the primary side voltage is sensed by 1000V, and after the capacitor voltage is superposed, the withstand voltage during the switch turn-off period is greatly reduced, the selection space of the switch is increased, and the cost is greatly reduced. Therefore, the primary/secondary winding ratio of the transformer is required to be 1:2, so that the working duty ratio of the switch can be greatly reduced, and the electric energy conversion efficiency of the power circuit unit is improved. Meanwhile, the output voltage of 1000V is converted to the primary side through a primary-secondary side 1:2 transformer, so that the voltage resistance of the switch in the turn-off period can be greatly reduced, the selection space of a switching tube is increased, and the cost is greatly reduced.

In one preferred embodiment, the ratio of the maximum value of the input voltage to the maximum value of the output voltage in the power supply circuit is V _{Into (I)} :V _{Out of} When the output power is 1000W-2000W, the primary side inductance of the transformer ranges from 50 mu H to 250 mu H, the capacitance parameter ranges from 200nF to 800nF, and the primary side/secondary side winding ratio of the transformer ranges from R _{Original source} :R _{Auxiliary pair} ＝2:1-5:1。

In this embodiment, by way of example and not limitation, the input voltage is 220V sine wave, that is, the maximum value of the input voltage is about 311V, the maximum value of the output voltage is about 40V, and the output power is 1000W, according to the above parameter design principle, the inductance of the primary winding of the transformer is set to about 150 μh-250 μh, the capacitance parameter is set to about 200nF-500nF, the ratio of the primary winding to the secondary winding of the transformer is set to about 5:1, and the corresponding electric energy conversion rate is at least 96%, and the experimental data and the test results of specific parameters are shown in examples 8-9 in table 1. Compared with the prior art, the power circuit has fewer components and less energy loss under the conditions of the same functions and the same electric energy conversion rate, and has lower cost and stronger circuit stability.

Specifically, in this embodiment, the output voltage is only 40V, and the output half-wave rectification module may use a switching device instead of a diode. Under the condition of low voltage, the output current is large, and a switching element with relatively low internal resistance needs to be selected.

In this case, the output voltage is only 40V, and a switching device may be used to replace a diode for output half-wave rectification, such as the fifth switch K5 in fig. 9. When selecting a switching element to replace a diode, care should be taken:

the first power circuit switches on the energy storage period, the input voltage is converted to the secondary side of the transformer through a 5:1 transformer, the output voltage is 40V, the voltage resistance of a selected switching element for replacing a switching element for half-wave rectification by a diode is about 311V/5+40V, the voltage resistance of the selected switching element is about 102.2V, and the voltage resistance of the selected switching element exceeds the value.

In the second, low voltage condition, the output current is large, and a switching element with relatively low internal resistance needs to be selected.

The switching device with fixed internal resistance can be adopted, the total internal resistance is reduced in a mode of parallel operation of a plurality of switching devices, and the conversion efficiency of output half-wave rectification can be effectively improved. Thereby improving the conversion efficiency of the whole circuit unit.

In this embodiment, by way of example and not limitation, the input voltage is a 380V sine wave, i.e., the maximum value of the input voltage is about 540V, the maximum value of the output voltage is about 100V, the ratio of the maximum value of the input voltage to the maximum value of the output voltage is about 5:1, and the output power is 2000W, where the primary winding inductance of the transformer is set to about 50 μh-150 μh, the capacitance parameter is set to about 400nF-800nF, the primary/secondary winding ratio of the transformer is set to about 2:1, and the corresponding power conversion rate is at least 97% according to the above-mentioned parameter design principle. Under the conditions of the same functions and the same electric energy conversion rate as the prior art, the number of components of the power circuit is far smaller than that of products of the same type in the market, the cost is far lower than that of products in the market, and the circuit stability is higher.

The embodiment is a case where the input voltage of the power supply circuit is high, the output voltage is low, and the output current is high. In practice, if a 1:1 transformer is used, the switching duty ratio may be too small, the frequency is too low, resulting in low conversion efficiency of the transformer, and further, the overall power conversion efficiency of the power supply circuit is reduced. The transformer with the ratio of 2:1-3:1 can be used for well solving the problem and improving the circuit conversion efficiency. At this time, it should be noted that the primary leakage inductance of the transformer from 2:1 to 3:1 increases, and if the primary leakage inductance is too large, a voltage spike is generated at the moment of switching off the switch, which results in damage to the switch, or a switch with higher withstand voltage needs to be used, which increases the cost. It is suggested that copper foil is used as primary and secondary side coils, and primary and secondary sides are wound in parallel to manufacture the transformer, so that leakage inductance of the primary and secondary sides of the transformer is reduced.

In this embodiment, the output voltage is only 100V, and it is recommended to use a switching element instead of a diode to perform output half-wave rectification, such as the fifth switch K5 in fig. 9, and it is considered to use a switching assembly in which a plurality of switching elements are connected in parallel to switch the power supply circuit, so as to reduce the conduction loss.

In one preferred embodiment, the ratio of the maximum value of the input voltage to the maximum value of the output voltage of the power supply circuit is V _{Into (I)} :V _{Out of} When the output power is 2000W-10000W, the primary side inductance of the transformer ranges from 50 mu H to 250 mu H, the capacitance parameter ranges from 200nF to 800nF, and the primary side/secondary side winding ratio of the transformer ranges from R _{Original source} :R _{Auxiliary pair} ＝1:1-2:1。

In this embodiment, by way of example and not limitation, under the conditions that the input voltage is 600V-1000V, the output voltage is 220V-380V, and the output power is 2000W-10000W, the inductance of the primary winding of the transformer is set to about 50 μh-250 μh, the capacitance parameter is set to about 100nF-800nF, the ratio of the primary winding to the secondary winding of the transformer is set to about 1:1-2:1, and the corresponding electric energy conversion rate is above 96%, and the experimental data and test results of specific parameters are shown in embodiment 10 in table 1. The inductance of the primary winding of the transformer is lower than 50 mu H, which may cause the frequency of the switching tube to be too high, and switching tubes such as IGBT and the like cannot be used, thereby increasing the cost; above 250 muh, the whole circuit may not output enough power or the switch may need to be operated at an extremely low frequency, reducing the transformer conversion efficiency. Compared with the prior art, the power supply circuit has the advantages that under the condition of equal power and equal efficiency, the number of components of the power supply circuit is far smaller than that of circuit products in the prior art, and the cost is far lower than that of the circuit products in the prior art.

In one preferred embodiment, when the input power of the power circuit unit is ac, the power circuit further comprises an input rectifying module providing a dc input to the inductor.

Specifically, when the input power is ac, the ac of the input power needs to be rectified, and the rectified dc flows into the inductor of the power circuit unit. In practice, the alternating current voltage is 220V, and other values are also available, and the value of the provided alternating current voltage can be changed according to the difference of single-phase or three-phase connection methods, for example, the three-phase power is 380V, so that the alternating current using environment in practice is met, the power circuit needs to be rectified through the input rectifying module, and the implementation mode of the specific rectifying module is not limited; any scheme that can be used to implement rectification in the present or future prior art is within the scope of the present application, as long as the scheme can be directly applied to the power circuit unit in the present embodiment, or the scheme can be applied to the power circuit unit in the present embodiment without the need for creative effort of a person skilled in the art.

Preferably, the input rectifying module of the power supply circuit is a full-wave rectifying circuit.

Specifically, when the input rectifying module is full-wave rectification, the sine wave alternating current is rectified into a steamed bread wave, the frequency of the rectified steamed bread wave is doubled, a specific circuit for realizing full-wave rectification is not limited, and any scheme capable of realizing full-wave rectification in the prior art now or in the future is within the scope of protection of the present application as long as the scheme can be directly applied to the scheme that the rectifying module of the input power supply in the present embodiment performs full-wave rectification when the input power supply is alternating current, or the scheme is applied to the present embodiment without creative labor of a person in the field after the scheme is changed, so that the circuit schemes capable of realizing full-wave rectification are all within the scope of protection of the present application.

Preferably, referring to fig. 4, the full-wave rectifying circuit is a full-bridge rectifying circuit.

Specifically, in fig. 4, before the ac power provided by the input power source is input to the inductor L, the ac power is rectified by a full-bridge rectifying circuit, and the rectified sine wave is output as a steamed bread wave and enters the power circuit unit.

Preferably, the input rectifying module of the power supply circuit is a half-wave rectifying circuit.

Specifically, the input rectifying module may be a half-wave rectifying circuit, the sine wave alternating current is rectified into an intermittent steamed bread wave, the frequency of the rectified steamed bread wave is unchanged, the circuit for realizing half-wave rectification is not limited, any scheme of the circuit capable of realizing half-wave rectification in the prior art now or in the future can be directly applied to the scheme of the circuit capable of realizing half-wave rectification as long as the scheme can be directly applied to the scheme of the rectifying module of the input power supply in the embodiment when the input power supply is alternating current, or the scheme is applied to the embodiment without creative labor of a person in the field after the scheme is changed, so that the scheme capable of realizing half-wave rectification is within the protection scope of the application, such as a diode/MOS (metal oxide semiconductor) tube with a unidirectional conduction function, a switch tube controlled to be unidirectional conduction, and the like.

Preferably, the output half-wave rectification module of the power circuit unit realizes half-wave rectification through a diode.

Specifically, referring to fig. 8, the output half-wave rectification module provided in this embodiment is connected to one end of the secondary winding in the transformer, and its specific principle of action is as follows: after a switch of a power circuit is turned from on to off, an inductor and a primary winding of a transformer start to discharge, current change of the primary winding of the transformer is induced to a complex winding of the transformer, a secondary winding of the transformer is induced by current of the primary winding to obtain electric energy, and at the moment, the current of the secondary winding of the transformer is output to an electrolytic capacitor or a load through the output half-wave rectification module to supply or store the electric energy; when the switch of the power circuit is turned from open to closed, the capacitor, the primary winding of the transformer and the switch form an equivalent LC resonant circuit, and the capacitor and the primary winding of the transformer form resonance at the moment because the voltage is not allowed to be suddenly changed by the capacitor.

Therefore, the output half-wave rectification module can only realize unidirectional conduction of the secondary winding current of the transformer, and a circuit or a component for realizing the output half-wave rectification is not limited, and any scheme of the circuit capable of realizing the half-wave rectification in the prior art in the present or future can be directly applied to unidirectional conduction of the secondary winding current of the transformer in the embodiment, or the scheme is applicable to unidirectional conduction of the secondary winding current of the transformer in the embodiment after the scheme is changed by a person skilled in the art without creative labor, so that the circuit schemes capable of realizing the half-wave rectification are all within the protection scope of the application, such as a diode/MOS tube with unidirectional conduction function, a switch tube controlled to be unidirectional conduction, and the like.

Further, referring to fig. 8, in this embodiment, the unidirectional output of the secondary winding of the transformer T is achieved by connecting a third diode D3 to the corresponding output terminal of the secondary winding of the transformer T. The diode has the property of unidirectional conduction, half-wave rectification is realized through the diode, and the control circuit is simple and has stable performance.

Preferably, referring to fig. 9, the output half-wave rectification module of the power circuit unit implements output half-wave rectification through a fifth switch K5 and a fifth controller for controlling the fifth switch K5; the fifth controller controls the switching mode of the fifth switch according to the mode that the controller of the power circuit unit controls the switch to induce electric energy for the secondary winding of the transformer.

Specifically, this embodiment is to implement half-wave rectification of the secondary winding output of the transformer by the fifth switch K5, where the fifth switch K5 is controlled by the fifth controller. Further, since the working state of the fifth switch K5 determines whether the secondary winding of the transformer can form a loop, that is, the fifth switch K5 is opened, which cannot form a loop, and the fifth switch K5 is closed, which can form a loop; meanwhile, when the switch closing capacitor of the power circuit resonates for charging the primary winding of the transformer, the secondary winding of the transformer cannot form a loop, i.e. the fifth switch K5 needs to be opened at the moment. The fifth controller needs to control the working state of the fifth switch K5 according to the working state of the switch in the power circuit, and according to the analysis, when the switch of the power circuit is in the closed state, the fifth controller needs to control the fifth switch K5 to be in the open state.

According to the embodiment, the function of half-wave rectification of the secondary winding output of the transformer is achieved by arranging the fifth controller and the corresponding fifth switch, and in certain scenes, the energy consumption of the switch relative to the diode is lower, and the electric energy conversion rate is higher. For example, and without limitation: under the scene that the output voltage is lower than 100V, a diode is used for half-wave rectification, the voltage drop of the diode is too high, so that the conversion efficiency is reduced, and the output half-wave rectification function of the secondary side of the transformer can be realized by using a switching element. The switching element with fixed internal resistance can be adopted, and a mode of parallel connection of multiple switches can be adopted, so that the power loss of half-wave rectification is reduced, and the electric energy conversion rate is improved.

Specifically, the switch in the power circuit carries the on and off functions of the circuit according to the control information of the corresponding controller, where the specific control mode of the controller to control the switch is not limited, that is, the mode or the way of the controller to provide the control signal to the switch is not limited, and the switch signal transmission scheme can be implemented by the controller in any existing or future prior art, so long as the scheme can be directly applied to the control signal transmission of the controller to the switch controlled by the controller in this embodiment, or the scheme is applicable to the switch controlled by the controller in this embodiment without creative labor of a person skilled in the art, and then the scheme for implementing the control signal transmission of the controller to the switch controlled by the controller is all within the protection scope of the application.

Further, the specific form of the switch or the switch and the controller thereof for realizing the circuit opening and closing in the power supply circuit is not limited, and any scheme for realizing the switch or the switch and the controller thereof for realizing the circuit opening and closing in the prior art now or in the future is within the scope of the present application as long as the scheme can be directly applied to the function of the circuit opening and closing in the power supply circuit of the present embodiment, or the scheme is applied to the present embodiment without the need of creative labor of a person skilled in the art.

Specifically, when the switch is closed in the working process of the power circuit, the input power supply charges the inductor, the switch is opened instantly, the current change of the primary winding of the transformer is larger, at the moment, leakage inductance of the transformer can cause a large voltage peak value to be generated at two ends of the switch, the switch is possibly damaged by the high voltage breakdown, and the leakage inductance value range of the transformer is optimally smaller than 1.5% in order to ensure high electric energy conversion rate and better stability of the power circuit.

Further, the specific structure of the transformer according to the present application is not limited, and any transformer structure scheme capable of achieving a leakage inductance of less than 1.5% in the prior art, either in the present or future, is within the scope of the present application as long as the scheme can be directly applied to the function of the transformer in the power circuit of the present embodiment, or the scheme is applied to the present embodiment without the need for creative labor of a person skilled in the art.

Preferably, the transformer in the power circuit is copper foil or U-shaped metal sheet, and the winding mode is parallel winding. Therefore, voltage spike caused by leakage inductance of the transformer T in a switch turn-off device can be effectively reduced, and the switch is protected. Furthermore, the power supply circuit can work under the working condition of higher power.

Specifically, the embodiment discloses a structure and winding mode of a transformer in a power circuit, wherein the magnetic core structure of the transformer is selected to be a sheet metal, or a U-shaped sheet metal, and the winding modes of the primary side and the secondary side of the transformer are parallel winding modes, so that leakage inductance of the transformer can be reduced, and the operation requirement of the power circuit is met.

Referring to fig. 5, the present application further provides a first extended power circuit, where when the input power is ac, the first extended power circuit includes the two power circuit units, the first extended power circuit includes a first power circuit unit, a second power circuit unit, a first information acquisition module for acquiring voltage/current information of the input and output ends of the first extended power circuit, a first diode D1 and a second diode D2 connected to the first and second power circuit units, respectively, and a first control center connected to the first information acquisition module for controlling a switching operation state in the first/second power circuit units.

The first power circuit unit X1 includes a first inductor L1, a first switch K1, a first transformer T1, and a first output half-wave rectification module; the second power circuit unit X2 includes a second inductor L2, a second switch K2, a second transformer T2, and a second output half-wave rectification module.

Specifically, in this embodiment, the first information acquisition module acquires the voltage/current of the input power source of the first extended power source circuit and the current/voltage information of the output end of the first extended power source circuit, the first information acquisition module transmits the acquired input and output voltage/current information to the first control center, and the first control center generates control information for controlling the first switch and the second switch according to the received information and transmits the control information to the first switch and the second switch, and controls the first switch and the second switch to execute instruction information such as duty ratio, frequency, switch state and the like in the control information.

Referring to fig. 5, two ends of an input power supply are respectively connected to the anodes of the first diode D1 and the second diode D2 and grounded, the cathode of the first diode D1 is connected to one end of a first inductor L1 of the first power supply circuit unit X1, the other end of the first inductor L1 is connected to one end of the first switch K1 and one end of the first capacitor C1, the other end of the first capacitor C1 is connected to one end of a primary winding of the first transformer T1, and the other end of the primary winding of the transformer and the other end of the first switch K1 are grounded; the negative pole of second diode D2 is connected with the one end of second inductance L2 of second power circuit unit X2, and the other end of second inductance L2 is connected with one end of second electric capacity C2 and one end of second switch K2, and the other end of second electric capacity C2 is connected with one end of the primary winding of second transformer T2, and the other end of transformer T2 primary winding and the other end of second switch K2 all ground connection.

Specifically, in this embodiment, the power supply circuit realizes the input half-wave rectification of each power supply circuit unit by respectively connecting two diodes D1 and D2 to two power supply circuit units, and referring to fig. 5, the components and the connection modes included in the first power supply circuit unit and the second power supply circuit unit included in the power supply circuit in this embodiment are shown.

The loop formed in the working process of the power supply circuit of this embodiment is: loop (1) [ input power+first inductance l1+first capacitance c1+first transformer T1 ], loop (2) [ input power+first inductance l1+first switch K1 ], loop (3) [ first capacitance c1+first transformer t1+first switch K1 ].

The specific operation procedure of the power supply circuit of this embodiment is as follows:

when the input power source inputs current to the anode of the first diode D1, the first control center controls the switch K2 of the second power circuit unit X2 to be in an off state, and the first power circuit unit X1 works normally.

At this time, the first power supply circuit unit X1 operates as follows: when the first control center controls the first switch K1 to be closed, the input power supply charges the first inductor L1, the first inductor L1 stores energy, the first inductor L1 generates a high voltage for keeping the current at the two ends of the first inductor L1 not to be suddenly changed at the moment of opening the first switch K1, the electric energy is transmitted through a new loop (1) formed after the first switch K1 is opened, and the first inductor L1 charges the first capacitor C1The power is induced to the secondary side of the transformer through the first transformer T1, and the voltage of the input power supply plus the voltage of the first inductor L1 is equal to the voltage of the first capacitor C1 plus the voltage of the primary winding of the first transformer T1, namely: v (V) _{Input power supply} +V _L1 ＝V _C1 +V _{T1 antigen} The method comprises the steps of carrying out a first treatment on the surface of the The first transformer T1 inducts electric energy to a secondary winding thereof, and the secondary winding outputs the electric energy to an electric energy supply output end of the power circuit unit through the half-wave rectification module to supply the electric energy to a load; when the first switch K1 is switched from an off state to an on state, a loop and a specific working process formed by the power circuit unit sequentially are as follows: the power supply circuit charges the first inductor L1 through the loop (2), the first capacitor C1 charges the primary winding of the transformer T through the loop (3), and the half-wave rectification module is arranged in the loop of the secondary winding of the first transformer T1, so that the first transformer T1 cannot transmit electric energy to the secondary winding of the first transformer T1, and at the moment, the primary winding of the first transformer T1 and the first capacitor C1 form an LC resonant loop, so that the electric energy of the loop is kept; meanwhile, after the first switch K1 is in a closed state, the first inductor L1 is charged by the input power of the (2) th loop, and the first inductor L1 stores energy next time.

The first switch K1 is turned off by the first control center until the half sine wave time provided by the input power is used up, the input power inputs the reverse current of the sine wave to the second inductor L2, the second power circuit unit X2 starts to work normally, and the working principle and process of the second power circuit unit X2 are completely consistent with those of the first power circuit unit X1, and accordingly, the description is omitted herein.

According to the embodiment, the two diodes are respectively connected into the two power supply circuits at the same time, and under the control of the first control center, one (for example, the first) power supply circuit unit normally works when the input power supply is in forward direction, and the other (for example, the second) power supply circuit normally works when the input current is in reverse direction, namely, the two sets of power supply circuits can normally work at the same time.

Preferably, the output terminal of the first power supply circuit unit for supplying power is connected in series or in parallel with the output terminal of the second power supply circuit unit for supplying power.

Specifically, referring to fig. 5, the output end of the first power circuit unit X1 for providing electric energy is the output end of the secondary winding of the transformer T1 after passing through the half-wave rectification module, the output end of the second power circuit unit X2 for providing electric energy is the output end of the secondary winding of the transformer T2 after passing through the half-wave rectification module, in this embodiment, the first power circuit unit X1 and the second power circuit unit X2 intermittently operate according to the waveform condition of the sine wave alternating current of the input power supply, and the two power circuit units do not output electric energy at the same time, and the output ends of the two power circuit units can be independently used as the output end for providing electric energy, or the output ends of the two power circuit units can be connected in parallel or in series; the output ends of the two are connected in parallel, so that the output current and the output power of the power supply circuit can be improved, and the electric energy output can be provided in the whole process of providing sinusoidal alternating current by the input power supply; the output ends of the two are connected in series, so that the range of the output voltage and the output power of the power supply circuit can be widened, and the whole process of providing sinusoidal alternating current at the input power supply can be ensured to provide electric energy output.

The application also provides a second extended power supply circuit, when the input power supply is alternating current, the second extended power supply circuit comprises the two power supply circuit units, namely a third power supply circuit unit and a fourth power supply circuit unit, a second information acquisition module for acquiring voltage/current information of the input end and the output end of the second extended power supply circuit, and a second control center connected with the second information acquisition module and used for controlling the working state of a switch in the third/fourth power supply circuit unit. Referring to fig. 6, the third power circuit unit X3 includes a third inductor L3, a third capacitor C3, a third switch K3, and a third transformer T3; the fourth power circuit unit X4 includes a fourth inductor L4, a fourth switch K4, a fourth capacitor C4, and a fourth transformer T4.

With continued reference to fig. 6, two ends of the input power supply are respectively connected with one ends of a third inductor L3 and a fourth inductor L4, and the other end of the fourth inductor L4 is connected with one ends of a fourth capacitor C4 and a fourth switch K4; the other end of the third inductor L3 is connected with one end of a third capacitor C3 and one end of a third switch K3; the other end of the third capacitor C3 is connected with the input end of the primary winding of the third transformer T3; the output end of the primary winding of the third transformer T3 is connected with the other end of the third switch K3, the other end of the fourth switch K4 and the output end of the primary winding of the fourth transformer T4 and grounded; the input end of the primary winding of the fourth transformer T4 is connected with the other end of the fourth capacitor C4.

Specifically, in this embodiment, in the case where the input power of the second extended power circuit is ac, an implementation scheme without a rectifying module is shown in fig. 6, which is a component and a connection manner of the component included in the third power circuit unit X3 and the fourth power circuit unit X4 included in the power circuit in this embodiment.

The loop formed in the working process of the power supply circuit of this embodiment is: the specific operation process of the power circuit of this embodiment is as follows:

when the input power supplies current to the third power circuit unit X3, the second control center controls the fourth switch K4 of the fourth power circuit unit X4 to be in a closed state, and the third power circuit unit X3 works normally as the first stage of the power circuit working process.

At this time, the working process of the first stage of the power supply circuit is as follows: when the second control center controls the third switch K3 of the third power supply circuit unit X3 to be closed, the input power supply charges the third inductor L3 and the fourth inductor L4, the third inductor L3 and the fourth inductor L4 store energy, and the third switch K3 is turned off instantly to supply third power The third inductor L3 and the fourth inductor L4 are to be discharged, the third inductor L3 and the fourth inductor L4 are to keep the current at the two ends of the third inductor L3 and the fourth inductor L4 not to be suddenly changed, a high voltage is generated, the electric energy is transmitted through a new loop (1) formed after the third switch K3 is opened, the third inductor L3 and the fourth inductor L4 are both charged by the third capacitor C3, the electric energy is induced to the secondary side of the third transformer T3 through the current change of the primary side of the third transformer T3, and the voltage of the input power supply plus the voltage of the third inductor L3 plus the voltage of the fourth inductor L4 is equal to the voltage of the third capacitor C3 plus the primary side winding of the third transformer T3, namely:the third transformer T3 senses electric energy to its secondary winding, which outputs the electric energy to the electric energy supply output end of the second extended power circuit through the output half-wave rectification module, and supplies the electric energy to the load.

When the third switch K3 is switched from the off state to the on state, the loop and the specific working process formed by the second extended power supply circuit are as follows: the power supply circuit charges a third inductor L3 and a fourth inductor L4 through a loop (2), a third capacitor C3 charges a primary winding of a third transformer T3 through a loop (3), and a half-wave rectification module is arranged in a loop of a secondary winding of the third transformer T3, so that the third transformer T3 cannot transmit electric energy to the secondary winding of the third transformer T3, and at the moment, the primary winding of the third transformer T3 and the third capacitor C3 form resonance to keep the electric energy in the loop; meanwhile, after the third switch K3 is in a closed state, the third inductor L3 and the fourth inductor L4 are charged through the input power supply of the (2) th loop, and the third inductor L3 and the fourth inductor L4 store energy next time.

Until the half sine wave time provided by the input power supply is used up, the second control center controls the third switch K3 of the third power supply circuit unit X3 to be in a closed state, the input power supply inputs the reverse current of the sine wave to the fourth inductor L4 of the fourth power supply circuit unit X4, and the fourth power supply circuit unit X4 starts to work normally, and the second stage of the work as a power supply circuit.

The specific operation principle and process of the power supply circuit in the second stage [ the normal operation of the fourth power supply circuit unit X4 ] are completely identical to those of the third power supply circuit unit X3 in the first stage, and accordingly, the description thereof will not be repeated here.

When the input power source is alternating current, the power source circuit of the embodiment does not use the rectifier module, and the two sets of power source circuits connected in a mirror mode are arranged, so that the input power source can charge and discharge simultaneously no matter in a forward direction or in a reverse direction, namely, the two inductors L3 and L4 are equivalent to be connected in series.

The application also provides a third extended power supply circuit, when the input power supply is alternating current, the third extended power supply circuit comprises the second extended power supply circuit which omits the inductor in the third or fourth power supply circuit unit, and the third extended power supply circuit takes the inductor which omits the fourth power supply circuit unit as an example, and takes the inductor which omits the fourth power supply circuit unit as an example, at the moment, the third extended power supply circuit comprises the third power supply circuit unit, the fourth power supply circuit unit which omits the fourth inductor, a third information acquisition module which is used for acquiring the voltage/current information of the input end and the output end of the third extended power supply circuit, and a third control center which is connected with the third information acquisition module and used for controlling the working state of a switch in the third/fourth power supply circuit unit.

Specifically, the third power circuit unit X3 includes a third inductor L3, a third capacitor C3, a third switch K3, a third transformer T3, and an output half-wave rectification module; the fourth power circuit unit X4 without inductance comprises a fourth capacitor C4, a fourth switch K4, a fourth transformer T4 and an output half-wave rectification module.

The connection mode of the components of the third power supply circuit unit and the fourth power supply circuit unit which omits the inductor in the third extended power supply circuit in this embodiment is identical to the connection mode of the components of the third power supply circuit and the fourth power supply circuit in the above embodiment, and only the fourth power supply circuit omits the fourth inductor L4, where the fourth inductor L4 is directly removed, and two ends of the original fourth inductor L4 are connected through a wire.

In this embodiment, the implementation scheme of the rectifying module is not set when the input power of the third extended power circuit is ac, and the scheme of the third inductor L3 or the fourth inductor L4 is omitted on the basis of the scheme that the third extended power circuit includes the third power circuit unit and the fourth power circuit unit.

The loop formed in the working process of the power supply circuit of this embodiment is: the circuit (1) [ input power supply+third inductance L3+third capacitance C3+third transformer T3+fourth switch K4 ], the circuit (2) [ input power supply+third inductance L3+third switch K3+fourth switch K4 ], the circuit (3) [ third capacitance C3+third transformer T3+third switch K3 ], the circuit (4) [ input power supply+third inductance L3+fourth capacitance C4+fourth transformer T4+third switch K3 ], the circuit (5) [ input power supply+third inductance L3+third switch K3+fourth switch K4 ], the circuit (6) [ fourth capacitance C4+fourth transformer T4+fourth switch K4 ].

when the input power supplies current to the third power supply circuit unit X3, the third control center controls the fourth switch K4 of the fourth power supply circuit unit X4 to be in a closed state, and the third power supply circuit unit X3 operates normally, here as the first stage of the power supply circuit operation.

Here, the operation procedure of the first stage of the third extended power supply circuit is as follows: the specific working process of the power supply circuit at the stage is as follows: when the third control center controls the third switch K3 of the third power supply circuit unit X3 to be closed, the input power supply charges the third inductor L3, the third inductor L3 stores energy, the third inductor L3 discharges at the moment when the third switch K3 is opened, the current at the two ends of the third inductor L3 is kept not to be suddenly changed,a high voltage is generated, the electric energy is transmitted through a new loop (1) formed after the third switch K3 is opened, the third inductor L3 charges the third capacitor C3, and the electric energy is induced to the secondary winding of the third transformer T3 through the primary winding of the third transformer T3, at this time, the voltage of the input power supply plus the voltage of the third inductor L3 is equal to the voltage of the third capacitor C3 plus the voltage of the primary winding of the third transformer T3, namely: The third transformer T3 senses electric energy to its secondary winding, which outputs the electric energy to the electric energy supply output end of the power circuit unit through the half-wave rectification module, and supplies the electric energy to the load.

When the third switch K3 is turned from the open state to the closed state, the loop and the specific working process formed by the third extended power supply circuit are as follows: the power supply circuit charges the third inductor L3 through the loop (2), and charges the primary winding of the third transformer T3 through the third capacitor C3 of the loop (3), and the half-wave rectification module is arranged in the loop of the secondary winding of the third transformer T3, so that the third transformer T3 cannot transmit electric energy to the secondary winding of the third transformer T3, and at the moment, the third transformer T3 is equivalent to the primary winding of the third transformer T3 and the third capacitor C3 to form an LC resonant loop, so that the electric energy in the loop is kept; meanwhile, after the third switch K3 is in a closed state, the third inductor L3 is charged through the input power of the (2) th loop, and the third inductor L3 stores energy next time.

Until the half sine wave time provided by the input power supply is used up, the third control center controls the third switch K3 of the third power supply circuit unit X3 to be in a closed state, the input power supply inputs the reverse current of the sine wave to the fourth power supply circuit unit X4 without the inductor, and the fourth power supply circuit unit X4 without the inductor works normally, and is used as the second stage of the working process of the power supply circuit.

At this time, the second stage of the power supply circuit operates as follows: when the third control center controls the fourth switch K4 of the fourth power supply circuit unit without the inductor to be closed, the input power supply charges the third inductor L3, the third inductor L3 stores energy, the third inductor L3 discharges at the moment when the fourth switch K4 is opened, and the third inductor L3 maintains the current at two ends of the third inductor L3If the voltage is not suddenly changed, a high voltage is generated, the electric energy is transmitted through a new loop (4) formed after the fourth switch K4 is opened, the third inductor L3 charges the fourth capacitor C4 and the primary winding of the fourth transformer T4, and the voltage of the input power supply plus the voltage of the third inductor L3 is equal to the voltage of the fourth capacitor C4 plus the primary winding of the fourth transformer T4, namely:the fourth transformer T4 senses electric energy to its secondary winding, which outputs the electric energy to an output terminal for supplying electric energy through an output half-wave rectification module, and supplies the electric energy to a load.

When the fourth switch K4 is switched from the off state to the on state, the loop and the specific working process formed by the power circuit unit are as follows: the power supply circuit charges the third inductor L3 through a loop (5), and charges the primary winding of the fourth transformer T4 through a loop (6), and the fourth capacitor C4 is used for maintaining the electric energy in the loop because the half-wave rectification module is arranged in the loop of the secondary winding of the fourth transformer T4, and the fourth transformer T4 can not transmit the electric energy to the secondary winding thereof at the moment, and is equivalent to the LC resonant loop formed by the primary winding of the fourth transformer T4 and the fourth capacitor C4 at the moment; meanwhile, after the fourth switch K4 is in a closed state again, the third inductor L3 is charged through the input power of the (2) th loop, and the third inductor L3 stores energy next time.

Until the half sine wave provided by the input power supply is used up, the power supply circuit enters the working process of the next first stage.

The second extended power supply circuit of this embodiment is the foregoing further optimization/transformation including the third and fourth two power supply circuits, that is, the inductor in one of the third or fourth power supply circuit units is omitted, so that the input power supply can discharge the primary winding of the third capacitor c3+third transformer T3 or the primary winding of the fourth capacitor c4+fourth transformer T4 according to the difference of the output current directions of the alternating current after being charged, that is, the scheme omits the rectifier module circuit, and simultaneously can realize that one inductor provides electric energy for two loops, thereby reducing energy loss, reducing circuit cost, remarkably improving the conversion rate of electric energy, and the performance of the whole circuit is better.

Preferably, the power supply output terminal of the third power supply circuit unit is connected in series or in parallel with the power supply output terminal of the fourth power supply circuit unit.

Specifically, referring to fig. 6 and fig. 7, the output end of the third power circuit unit X3 for supplying electric energy is the output end of the transformer T3 secondary winding after passing through the half-wave rectification module, the output end of the fourth power circuit unit X4 [ including the fourth power circuit unit X4 with no inductance ] for supplying electric energy is the output end of the transformer T4 secondary winding after passing through the half-wave rectification module, in the above embodiment, the third power circuit unit X3 and the fourth power circuit unit X4 intermittently and alternately operate according to the waveform condition of the sine wave ac of the input power supply, and the output ends of the third power circuit unit X3 and the fourth power circuit unit X4 do not output electric energy at the same time, and can be used as the output ends for supplying electric energy alone, or the output ends of the two can be connected in parallel or in series; the output ends of the two are connected in parallel, so that the output current of the power supply circuit can be improved, and the electric energy output can be provided in the whole process of providing sinusoidal alternating current by the input power supply; the output ends of the two are connected in series, so that the output voltage of the power supply circuit can be improved, and the whole process of providing sine alternating current at the input power supply can be ensured to provide electric energy output.

Referring to fig. 10, the present application further provides a method for implementing power factor tracking and voltage boosting/reducing simultaneously by using a power supply circuit, where the power supply circuit is the above power supply circuit, and the first, second, and third extended power supply circuits, and the method includes:

step S1, current actual input current, input voltage, output voltage and output current values are dynamically obtained.

Specifically, in the step S1, the current actual input and actual output conditions of the power supply circuit unit need to be dynamically acquired, wherein the specific acquisition or acquisition mode is not limited, the acquired information can be acquired through the acquisition unit of the controller, the acquired information can also be acquired through other modes, the acquired information is transmitted to the controller, the frequency of the dynamic acquisition can be referred to the frequency of a switch in the power supply circuit unit, for example, the frequency can be equal to or smaller than the switching frequency, the frequency of the dynamic acquisition can be adjusted according to the actual conditions, and the specific limitation is not limited; the voltage/current/power value required for the load of the power supply circuit unit is also obtained here according to the actual use situation.

And S2, comparing the acquired current actual output power with the target output power required by the access load.

Specifically, in the step S2, the obtained current actual output power [ output current output voltage ] is compared with the target output power required by the access load, and when the access load or the scene used by 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 larger than the target output power, the actual output power is higher than the target output power, the actual output power needs to be reduced, and when the actual output power is smaller than the target output power, the actual output power does not meet the requirement of the target output power, and the actual output power needs to be improved.

And step S3, dynamically determining a target input current value according to a comparison result of the current actual output power and the target output power.

Preferably, the step S3 includes:

s31, dynamically adjusting the peak value of the input current according to the comparison result of the step S2;

s32, dynamically determining a target input current value according to the input current peak value adjusted in the S31 and the currently input phase information.

In the step S31, according to the comparison result between the actual output power and the target output power, an input current peak value (i_in_peak) is dynamically determined, and if the actual output power is smaller than the target output power, the input current peak value is increased to increase the current actual output voltage or current, so as to further increase the actual output power to meet the load requirement; if the actual output power is greater than the target output power, the peak value of the input current is reduced to reduce the current actual output voltage or current, and the output power is further reduced to meet the load requirement, wherein the increasing or decreasing amplitude of the peak value of the input current needs to consider the difference between the actual output power and the target output power, for example, if the difference exceeds a preset value, the increasing amplitude of the peak value of the input current is increased to quickly meet the load requirement, and the like.

Specifically, in the step S32, a target input current value [ I target input current value=i input current peak value ] is dynamically determined according to the input current peak value [ i_in_peak ] and the currently input phase information [ current input voltage/input voltage peak value ], where the currently input phase information is a ratio of a current actual input voltage provided by the current input power supply to the power supply circuit unit and a periodically fluctuating voltage peak value provided by the input power supply to the power supply circuit unit, and the target input current value is a product of the input current peak value and the phase information determined in the step S31, that is:

I _{Target input current value} ＝I_in_peak*V _{Current actual input voltage value} /V _{Peak value of input voltage}

preferably, the step S4 includes:

when the current actual input current value is smaller than the target input current value, increasing the duty ratio of the switch or reducing the frequency of the switch; and when the current actual input current value is larger than the target input current value, reducing the duty ratio of the switch or increasing the frequency of the switch.

Specifically, when the current actual input current value is smaller than the target input current value, the controller generates instruction information for reducing the switching frequency and improving the switching duty ratio, and further controls the charge/discharge time of the inductor, so that the input current is improved, the power factor tracking requirement is met, and meanwhile, the output control is realized through the approximation of the current actual input current to the target input current value; otherwise, when the current actual input current value is larger than the target input current adjustment value, generating instruction information for increasing the switching frequency and reducing the switching duty ratio in the controller, further controlling the charging/discharging time of the inductor by controlling the working state of the switch, thereby reducing the input current, meeting the requirement of power factor tracking, and simultaneously realizing the control of the output of the power circuit unit by approaching the current actual input current to the target input current value.

Specifically, the magnitude of the decreasing/increasing switch duty ratio and the magnitude of the increasing/decreasing switch frequency need to be determined according to the difference between the current actual input current value and the target input current value, and the specific implementation manner and process are not limited, so that one of ordinary skill in the art can make an attempt to set according to the actual scene.

And S5, executing the instruction information through a switch of the power circuit unit, controlling the charge and discharge time of the inductor to dynamically adjust, and controlling the current actual input current value of the power circuit unit to approach the target input current value, so that the power circuit unit simultaneously realizes power factor tracking and dynamic adjustment of voltage rise/drop according to the output requirement.

Preferably, the step S5 includes:

the switch executes instruction information for increasing the duty ratio or reducing the frequency to increase the time length of charging the inductor, increase the current output power of the power supply circuit, further cause the current input power of the power supply circuit to increase, increase the current actual input current value and approach the target input current value;

the switch executes instruction information for reducing the duty ratio or increasing the frequency, so that the time duration of charging the inductor is reduced, the current output power of the power supply circuit is reduced, the current input power of the power supply circuit is further reduced, the current actual input current is reduced, and the current actual input current is close to the target input current value.

In the step S5, the switch of the power circuit unit dynamically executes the instruction information to control the charge and discharge time of the inductor in the power circuit unit, so that the current actual input current value of the power circuit unit approaches the target input current value as much as possible; specifically, the switch of the power circuit unit dynamically executes the command sent by the controller for adjusting the current duty ratio or frequency, and controls the charge and discharge time and frequency of the inductor in the power circuit unit, so that the current actual input current value of the power circuit unit approaches the target input current value as much as possible, and meanwhile, the target input current value covers the phase information of the current input voltage, namely, the phase information of the current input power supply is considered when the current actual input current value is adjusted according to the target input current value, the current actual input current value is ensured to approach the target input current value all the time, and the current actual input current value fluctuates around the target input current value, so that the power circuit unit has PFC (power factor tracking) capability, and the control of the output power is realized while the power factor tracking is realized, namely, the dynamic adjustment of rising/falling according to the output requirement.

In this embodiment, under the condition that the period corresponding to the switching frequency is higher than the frequency of the periodically fluctuating input power supply by multiple orders, by the control mode, the power factor tracking is well realized by matching the inductance in the power circuit unit with the frequency dynamic adjustment of the switch, and the dynamic adjustment of the voltage boosting and the voltage reducing according to the requirement of the load on the output voltage/current is well realized, so that the power circuit can simultaneously realize the power factor tracking under the scene of alternating current and larger power (more than 200 watts)/larger power, and dynamically boost/buck according to the requirement of the load. As previously mentioned, taking as an example a charging module product with a full load efficiency of 95.5% and a power of 30kW, the energy consumption per hour produced by the prior art product is (1-95.5%). 30 kW. 1h=1.35 kWh; the power supply circuit of the application can effectively improve the electric energy conversion efficiency, and can improve the product conversion rate to more than 30kW to 97 percent or more, and the full-load efficiency of the power supply circuit of the application is 97 percent, the power consumption of the same power per hour is about 3 percent 30kW 1 h=0.9 kWh, compared with the prior art, compared with the power supply circuit unit of the application, the power supply circuit unit can save 0.45kWh per hour, and according to 3000 hours of working per year, each power supply circuit product can save 1350kWh per year, thereby obviously, compared with the prior art, the application can greatly save energy.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

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Claims

1. A power supply circuit, the power supply circuit comprising: the system comprises an information acquisition module, a power circuit unit and a controller, wherein the power circuit unit comprises an inductor, a switch, a capacitor, a transformer and an output half-wave rectification module;

one end of an input power supply for providing electric energy for the power supply circuit unit is connected with one end of the inductor, and the other end of the inductor is connected with one end of the capacitor and one end of the switch; the other end of the capacitor is connected with one end of a primary winding of the transformer; the other end of the switch and the other end of the primary winding of the transformer are connected with the other end of the input power supply and grounded; one output end of the secondary winding of the transformer is connected with the output half-wave rectification module, and the output end of the half-wave rectification module and the other output end of the secondary winding of the transformer are output ends of the power circuit unit for providing electric energy for a load;

The information acquisition module is used for acquiring information of the input end and/or the output end of the power circuit unit;

2. The power supply circuit according to claim 1, wherein the power supply circuit inputs a voltage maximum V _{Into (I)} And the maximum value V of the output voltage _{Out of} Is in the ratio of V _{Into (I)} :V _{Out of} When the output power is larger than 200W, the parameter range of the capacitor is 30nF-3 mu F, and the inductance range of the primary winding of the transformer is 10 mu H-1000 mu H; the proportion range of primary side winding to secondary side winding of the transformer is R _{Original source} :R _{Auxiliary pair} ＝1:5-5:1。

3. The power supply circuit of claim 2, wherein the ratio of the maximum input voltage to the maximum output voltage in the power supply circuit is V _{Into (I)} :V _{Out of} When the output power is 200W-1000W, the inductance of the primary winding of the transformer ranges from 10 mu H to 1000 mu H, the parameter of the capacitor ranges from 100nF to 3 mu F, and the ratio range of the primary winding to the secondary winding of the transformer is R _{Original source} :R _{Auxiliary pair} ＝1:5-1:1。

4. The power supply circuit of claim 2, wherein the ratio of the maximum input voltage to the maximum output voltage in the power supply circuit is V _{Into (I)} :V _{Out of} When the output power is 1000W-2000W, the primary inductance of the transformer ranges from 50 mu H to 250 mu HThe capacitance parameter range is 200nF-800nF, and the primary side/secondary side winding proportion range of the transformer is R _{Original source} :R _{Auxiliary pair} ＝2:1-5:1。

5. The power supply circuit of claim 2, wherein the ratio of the maximum input voltage to the maximum output voltage in the power supply circuit is V _{Into (I)} :V _{Out of} When the output power is 1000W-2000W, the primary side inductance of the transformer ranges from 30 mu H to 1000 mu H, the capacitance parameter ranges from 50nF to 3 mu F, and the primary side/secondary side winding ratio of the transformer ranges from R _{Original source} :R _{Auxiliary pair} ＝1:2-2:1。

6. The power supply circuit of claim 2, wherein the ratio of the maximum input voltage to the maximum output voltage of the power supply circuit is V _{Into (I)} :V _{Out of} When the output power is 2000W-10000W, the primary side inductance of the transformer ranges from 50 mu H to 250 mu H, the capacitance parameter value ranges from 200nF to 800nF, and the primary side/secondary side winding ratio range of the transformer is R _{Original source} :R _{Auxiliary pair} ＝1:1-2:1。

7. The power supply circuit according to any one of claims 1 to 6, characterized in that when the input power of the power supply circuit unit is alternating current, the power supply circuit further comprises an input rectifying module providing a direct current input to the inductor.

8. The power supply circuit according to any one of claims 1 to 6, characterized in that the output half-wave rectification module of the power supply circuit unit implements half-wave rectification by means of diodes.

9. The power supply circuit according to any one of claims 1 to 6, wherein the output half-wave rectification module of the power supply circuit unit implements half-wave rectification by a fifth switch and a fifth controller that controls the fifth switch.

10. The power circuit of claim 9, wherein the fifth controller controls a switching mode of the fifth switch in accordance with a mode in which the controller of the power circuit controls the switch to induce power to the secondary winding of the transformer.

11. A power supply circuit according to any of claims 1-6 and 10, characterized in that the switching of the power supply circuit unit is realized by a bi-directional switch, a switching assembly or a controllable switching device.

12. The power supply circuit according to any one of claims 1 to 6 and 10, wherein the transformer leakage inductance value range in the power supply circuit unit is less than 1.5%.

13. The power supply circuit according to any one of claims 1 to 6 and 10, wherein the transformer structure in the power supply circuit unit is copper foil or U-shaped metal sheet, and the winding manner is parallel winding.

14. The power supply circuit according to any one of claims 1 to 6 and 10, wherein the inductance of the power supply circuit cooperates with the control of the switching state by the controller to enable the power supply circuit to simultaneously achieve power factor tracking and dynamic regulation of the step-up/step-down according to output requirements.

15. A first extended power circuit, when the input power is ac, comprising two power circuit units according to any one of claims 1 to 14, the first extended power circuit comprises a first power circuit unit, a second power circuit unit, a first information acquisition module for acquiring voltage/current information of input and output ends of the first extended power circuit, a first diode and a second diode respectively connected with the first and second power circuit units, and a first control center connected with the first information acquisition module for controlling the working state of a switch in the first/second power circuit units.

16. The first extended power supply circuit according to claim 15, wherein when an input power supply inputs a current to the first power supply circuit unit through the first diode, the first control center controls the switch of the second power supply circuit unit to be in an off state, and the first power supply circuit unit operates normally;

17. The first extended power supply circuit according to claim 15 or 16, wherein an output terminal of the first power supply circuit that supplies power is connected in series or in parallel with an output terminal of the second power supply circuit that supplies power.

18. A second extended power circuit, wherein when the input power is ac, the second extended power circuit comprises two power circuit units as claimed in any one of claims 1 to 14, a third power circuit unit and a fourth power circuit unit, a second information acquisition module for acquiring voltage/current information of the input and output ends of the second extended power circuit, and a second control center connected with the second information acquisition module for controlling the on/off states of the third/fourth power circuit units.

19. The second extended power supply circuit according to claim 18, wherein an output terminal of the third power supply circuit unit that supplies power is connected in series or in parallel with an output terminal of the fourth power supply circuit unit that supplies power.

20. The second extended power supply circuit according to any one of claims 18 or 19, wherein when an input power supply inputs a current to the third power supply circuit unit, the second control center controls the switch of the fourth power supply circuit unit to be in a closed state, and the third power supply circuit unit operates normally;

21. A third extended power supply circuit, characterized in that when the input power is an alternating current, the third extended power supply circuit comprises the second extended power supply circuit of any one of claims 18 to 20, which omits an inductance in the third or fourth power supply circuit unit.

22. A method for a power supply circuit to simultaneously achieve power factor tracking and step-up/step-down, wherein the power supply circuit is the power supply circuit of any one of claims 1 to 14, or the first extended power supply circuit of any one of claims 15 to 17, or the second extended power supply circuit of any one of claims 18 to 20, or the third extended power supply circuit of claim 21, the method comprising: