WO2022188873A1

WO2022188873A1 - Multi-path output converter and control method therefor

Info

Publication number: WO2022188873A1
Application number: PCT/CN2022/080435
Authority: WO
Inventors: 严宗周
Original assignee: 深圳原能电器有限公司
Priority date: 2021-03-12
Filing date: 2022-03-11
Publication date: 2022-09-15
Also published as: CN112865547A; CN112865547B

Abstract

Provided in the embodiments of the present application are a multi-path output converter and a control method therefor. The multi-path output converter comprises: a power conversion circuit and an output circuit, the power conversion circuit comprising a transformer or an inductor, and the output circuit comprising at least two paths of output units, wherein each path of output unit comprises an output capacitor and at least one switch tube and/or diode, the at least one switch tube and/or diode being connected in series to the output capacitor, and each of the output capacitors being respectively used for connecting a different load. The method comprises: according to load energy required by an output unit of a corresponding path, allocating energy stored in a transformer or an inductor to the corresponding path, such that a rated voltage or a variable voltage is output. In the technical solution, at an output end of a converter, a switch tube and an output capacitor are connected in series and form a multi-path output, and control is performed in a dynamic energy distribution mode, such that quick response outputs of multiple paths of different voltages or variable voltages can be realized, the structure is simple, and system loss, etc. is also reduced.

Description

A multi-output converter and its control method

technical field

The present application relates to the technical field of power conversion, and in particular, to a multi-output converter and a control method thereof.

Background technique

In the prior art, when realizing multiple outputs, it is usually necessary to output different turns ratios through multiple windings on the transformer. Since the turns ratio of this circuit output is fixed, variable voltage output cannot be realized, and multiple outputs are required. When the output load is unbalanced among several channels, the voltage of the no-load circuit part will be artificially high. As for the other method, it is to boost the voltage first and then step down. In the step-down process, a BUCK circuit is required, which will make each circuit need to set an inductor to achieve the step-down, which not only takes up space, but also has two stages. Conversion will also add large losses. Of course, there is another way to use multiple transformers for multiple outputs, which is highly efficient, but several transformers are needed for several outputs, and one transformer can only provide one output, such as a 65W transformer, which is used for 5.1V output. When it reaches 5W, the remaining 60W will be idle and cause waste of resources.

SUMMARY OF THE INVENTION

In view of this, in order to overcome the deficiencies in the prior art, the present application provides a multi-channel output converter and a control method thereof.

Embodiments of the present application provide a control method for a multi-output converter, the multi-output converter includes a power conversion circuit and an output circuit connected to the power conversion circuit, the power conversion circuit includes a main switch tube and The transformer or inductor connected to the main switch tube, the output circuit includes at least two output units, wherein each output unit includes an output capacitor, and at least one switch tube and/or diode, the at least one output unit A switch tube and/or a diode are connected in series with the output capacitor, the transformer or the inductor is used to connect a power supply or an energy storage capacitor, and each of the output capacitors is used to connect a different load; the method includes:

According to the load energy required by the output unit of the corresponding circuit, the energy stored in the transformer or the inductor is distributed to the corresponding circuit for rated voltage or variable voltage output.

In some embodiments, the output unit is a fixed output unit, a unidirectional controllable output unit or a bidirectional controllable output unit, wherein the fixed output unit includes a diode or a switch tube, the unidirectional controllable output unit includes a diode and a switch tube connected in series with the output capacitor, and the bidirectional controllable output unit includes two switch tubes connected in series with the output capacitor;

Wherein, during energy distribution, the switch tube in the unidirectional controllable output unit or the bidirectional controllable output unit is controlled to be in a conducting state until the voltage of the output capacitor in the corresponding circuit reaches the required voltage Or when the energy of the converter is released, the switch tube in the corresponding circuit is controlled to be turned off.

In some embodiments, the multi-output converter further includes: a rectifier tube, wherein if the power conversion circuit adopts the transformer to store energy, the rectifier tube and the secondary winding of the transformer are connected in series and then in parallel is connected to the output unit of each channel; if the power conversion circuit adopts the inductive energy storage, the output end of the power conversion circuit is connected in series with the rectifier tube and then connected in parallel to the output unit of each channel;

The method further includes: rectifying the voltage output by the transformer or the inductor through the rectifier tube, and then outputting the voltage to the output unit of the corresponding channel.

In some embodiments, the multi-output converter further includes: a reverse power supply module, the reverse power supply module includes a rechargeable component, wherein, if the power conversion circuit uses the transformer to store energy, the reverse power supply module is located in the Two ends of the rechargeable component in the output unit are respectively connected to two ends of the secondary winding through a switch; if the power conversion circuit adopts the inductive energy storage, the Two ends of the rechargeable component are respectively connected to two ends of the inductor through a switch;

The method further includes: when the input terminal of the power conversion circuit is not connected to the input voltage, turning on the switch tube connected to the two ends of the rechargeable component, so that the rechargeable component passes through the transformer or the switch. The inductance back-powers the input of the power conversion circuit.

In some embodiments, distributing the energy stored in the transformer or the inductor in the power conversion circuit to the corresponding circuit according to the load energy required by the output unit of the corresponding circuit includes:

According to the load energy required by the output unit of the corresponding channel, the energy stored by the transformer or the inductor in the power conversion circuit in one or more cycles is allocated to a single channel.

The energy stored by the transformer or the inductor in the power conversion circuit in one cycle is sequentially distributed to the output units with load energy demand.

In some embodiments, the multi-output converter is a primary-side feedback architecture, and the primary-side feedback architecture includes a transformer, a main switch tube and a primary controller connected in sequence, and the primary controller is used to control the main switch tube; the method includes:

The output voltage of each output unit is detected in a preset manner, and the highest output voltage among the detected output voltages is fed back to the primary controller as a reference voltage, so that the primary controller can The reference voltage controls the main switch tube, thereby adjusting the output voltage of the corresponding circuit.

Set a specified voltage as the reference voltage, detect the waveform voltage of the transformer in a specified period of time, and feed back the waveform voltage to the primary controller, so that the primary controller can make the feedback based on the feedback voltage and the reference voltage. The main switch tube is controlled to adjust the output voltage of the corresponding circuit.

In some embodiments, the multiple-output converter is a secondary-side feedback architecture, and the secondary-side feedback architecture includes a transformer, a main switch, a primary controller, a secondary controller and an optocoupler, which are connected in sequence, wherein , the signal input end of the optocoupler is connected to the secondary controller, and the signal output end is connected to the primary controller; the method includes:

The secondary controller detects the output voltage of each output unit in real time, and selects one of the outputs as a reference to feed back to the primary master. The reference selection adopts one of the following methods: selecting the highest voltage among the multiple channels; Or choose one of them to fix; or dynamically select the reference voltage from the current circuit that provides energy; and then transmit the required voltage or current signal to the primary controller through the optocoupler according to the signal fed back by the reference, and the primary control The transformer controls the main switch tube according to the obtained secondary voltage or current signal, and then controls the energy transmitted by the transformer.

In some embodiments, the power conversion circuit further includes a clamping switch and a clamping capacitor, wherein one end of the primary winding of the transformer is connected to one end of the clamping capacitor, and the other end of the primary winding is connected to one end of the clamping capacitor. One end of the main switch tube and the clamp switch tube are respectively connected, and the other end of the clamp switch tube is connected to the other end of the clamp capacitor; the method further includes:

In the initial stage of demagnetization, when the winding voltage of the transformer is higher than the voltage of the clamping capacitor, the main switch is controlled to be turned on, and after reaching the first preset voltage, the main switch is controlled to be turned off so that the transformer outputs energy to the output circuit;

After the demagnetization is completed, when the winding voltage of the transformer drops to the voltage of the clamping capacitor, the clamping switch is controlled to be turned on, so that the clamping capacitor outputs energy to the converter;

After a preset time period, the clamp switch is turned off or when it is detected that the voltage of the clamp capacitor drops to a second preset voltage, the clamp switch is controlled to be turned off, and the flyback voltage of the winding reaches the valley bottom Or when the voltage is zero, the main switch tube is controlled to be turned on again.

In some embodiments, if the power conversion circuit includes a transformer and a main switch tube connected to the transformer, and an input capacitor is provided at the input end of the power conversion circuit, the method further includes:

Controlling two switches in one or more bidirectional controllable output units in the output circuit to conduct, so as to release the electricity in the output capacitor in the corresponding circuit to the transformer;

The primary switch in the power conversion circuit is controlled to be turned on, so as to store the energy in the transformer in the input capacitor to realize bidirectional output.

Embodiments of the present application further provide a multi-output converter, comprising: a power conversion circuit and an output circuit connected to the power conversion circuit, the power conversion circuit comprising a main switch tube and a main switch tube connected to the main switch tube a transformer or an inductor, the output circuit includes at least two output units;

Wherein, each output unit includes an output capacitor, and at least one switch tube and/or diode, the at least one switch tube and/or diode are connected in series with the output capacitor, and each of the output capacitors is used to connect different The transformer or the inductor is used to connect the power supply or the energy storage capacitor, and each of the output capacitors is respectively used to obtain the energy stored in the transformer or the inductor to provide the load to the load.

In some embodiments, the output unit is a unidirectional fixed output unit, a bidirectional fixed output unit, a unidirectional controllable output unit or a bidirectional controllable output unit;

The unidirectional fixed output unit includes a diode connected in series with the output capacitor, the bidirectional fixed output unit includes a switch tube connected in series with the output capacitor, and the unidirectional controllable output unit includes A diode and a switch tube are connected in series with the output capacitor, and the bidirectional controllable output unit includes two switch tubes connected in series with the output capacitor.

In some embodiments, the multiple-output converter further includes: a rectifier;

If the power conversion circuit includes the transformer, the rectifier tube and the secondary winding of the transformer are connected in series and output, and each output unit is connected in parallel to both ends of the output;

If the power conversion circuit includes the inductor, the output end of the power conversion circuit is connected in series with the rectifier tube and then connected to each output unit.

In some embodiments, the multi-output converter further includes: a reverse power supply module;

The reverse power supply module includes a rechargeable component, wherein, if the power conversion circuit adopts the transformer to store energy, both ends of the rechargeable component located in the output unit are respectively connected to the secondary side through a switch tube. both ends of the winding;

If the power conversion circuit adopts the inductive energy storage, both ends of the rechargeable component located at the output end of the power conversion circuit are respectively connected to the two ends of the inductance through a switch tube.

The embodiments of the present application have the following beneficial effects:

The technical solution of the present application is at the output end of the universal converter, by connecting a switch tube or diode in series with an output capacitor, and setting it in parallel according to actual needs to form multiple outputs, and through dynamic distribution control, realize which way needs energy. When the switch tube of the corresponding circuit is turned on, the energy can be directly absorbed from the inductance or transformer in the converter, so as to realize the fast response output of multiple different voltages or variable voltages, the structure is simple, and the system loss is greatly reduced.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present application more clearly, the following drawings will briefly introduce the drawings that need to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore do not It should be regarded as a limitation of the scope, and for those of ordinary skill in the art, other related drawings can also be obtained according to these drawings without any creative effort.

FIG. 1 shows a first structural schematic diagram of a multi-output converter according to an embodiment of the present application;

FIG. 2 shows a schematic structural diagram of a non-isolated converter including a rectifier tube of a multi-output converter according to an embodiment of the present application;

3 shows a schematic structural diagram of an isolated converter including a rectifier tube and a reverse power supply module of a multi-output converter according to an embodiment of the present application;

4 shows a schematic structural diagram of a non-isolated converter including a rectifier tube and a reverse power supply module of a multi-output converter according to an embodiment of the present application;

FIG. 5 shows a schematic structural diagram of a multiple-output converter according to an embodiment of the present application applied to a primary-side feedback architecture;

FIG. 6 shows a schematic structural diagram of a multiple-output converter according to an embodiment of the present application applied to a secondary-side feedback architecture;

7 shows a schematic structural diagram of a multi-output converter in an embodiment of the present application including half-wave symmetric transformation and single-stage PFC transformation;

FIG. 8 shows a flowchart of a control method of a multiple-output converter according to an embodiment of the present application;

Fig. 9 shows the waveform schematic diagram of the whole cycle distribution of the single-channel output of the control method of the multi-channel output converter according to the embodiment of the present application;

FIG. 10 shows a schematic diagram of the first waveform of the single cycle distribution multiplexing of the control method for the multiplex output converter according to the embodiment of the present application;

FIG. 11 shows a schematic diagram of the second waveform of the single cycle distribution multiplexing of the control method of the multiplex output converter according to the embodiment of the present application;

FIG. 12 shows a control flow diagram of the control method of the multiple-output converter according to the embodiment of the present application applied to the primary-side feedback architecture;

FIG. 13 shows a control flow diagram of the control method of the multiple-output converter according to the embodiment of the present application applied to the secondary-side feedback architecture;

FIG. 14 shows a control flow chart of the control method of the multiple-output converter according to the embodiment of the present application applied to the ACF circuit.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

The components of the embodiments of the present application generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations. Thus, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the application as claimed, but is merely representative of selected embodiments of the application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

Example 1

Referring to FIG. 1 , the present embodiment proposes a multi-output converter, which can be used for fast response output of different voltages and/or variable voltages to meet different user requirements and the like.

Exemplarily, the multi-output converter includes: a power conversion circuit and an output circuit connected to the power conversion circuit, wherein the power conversion circuit includes a main switch tube Q1 and a transformer or an inductor connected to the main switch tube Q1, The output circuit includes at least two output units. It can be understood that the transformer or the inductor is used to connect the connected power supply or the energy storage capacitor, and is combined with the on and off control of the main switch tube Q1 for energy storage.

In this embodiment, the output circuit includes multiple output units, wherein each output unit includes an output capacitor and at least one switch and/or diode, and the at least one switch and/or diode is connected to the output capacitor in series. Each output capacitor is used to connect a different load.

Wherein, for the structure of each output unit, this embodiment can be divided into types according to different functional characteristics, for example, taking whether the output voltage is variable as an example, the output unit can be divided into a fixed output unit and a controllable output unit; Taking whether bidirectional control can be realized as an example, the output unit can be divided into a unidirectional output unit and a bidirectional output unit. Furthermore, the following types of output units can be obtained by combining different functions, such as unidirectional fixed output units, bidirectional fixed output units, unidirectional controllable output units and bidirectional controllable output units.

In one embodiment, as shown in FIG. 1 , the unidirectional fixed output unit is mainly composed of an output capacitor and a diode connected in series; the bidirectional fixed output unit is mainly composed of an output capacitor and a switch; the unidirectional controllable The type output unit mainly includes a diode and a switch tube connected in series with the output capacitor, while the bidirectional controllable output unit mainly includes two switch tubes connected in series with the output capacitor.

It can be understood that the user can select one or any combination of outputs according to actual needs. For example, for situations where long-term fixed output at the highest voltage is required and there is a light load or a load circuit for a long time, only one diode DOA or switch QOB is added to prevent backflow, as shown in branches A and B in Figure 1. For another example, for situations that are not loaded for a long time or require variable voltage output, a diode DOC and a switch QOC can be added in series on the basis of the output capacitor, as shown in branch C in Figure 1. For another example, for situations that require variable voltage output, or require high efficiency, or require reverse flow, it can be implemented by using two switches QOD and QOD1 in series, as shown in branch D in Figure 1.

It is worth noting that, for the above-mentioned types of output units, the structures of branches A and C can generally be used for low-current circuits; while for high-current circuits, such as fast charging, the structures of branches B and C are preferred. It should be understood that, for the occasion where only one channel of variable voltage output is required, only the branch D composed of two switch tubes connected in series can also be selected for implementation.

In this embodiment, the power conversion circuit is a general-purpose converter, for example, it can be an isolated converter, such as a transformer, or a non-isolated converter, such as a buck, boost, etc. circuit composed of an inductance. Of course, the power conversion circuit may also be a forward converter, a flyback converter, or the like, or a converter with different architecture types such as primary-side feedback, secondary-side feedback, and bilateral feedback. It can be understood that the design of the multiple outputs can be applied to various converter structures, and the structure of the power conversion circuit is not limited here.

Further, the multi-output converter further includes a rectifier tube located at the output side of the power conversion circuit, for example, the rectifier tube may be a diode or a synchronous switch tube. As a shared rectifier, the rectifier is used to uniformly rectify the voltage output by the transformer or inductor and then output it to each output unit, which can not only reduce the cost, but also reduce the switching tube and diode in each output unit. Pressure resistance, etc. This is because, when the rectifier does not exist, the diode or switch in each output needs to be greater than the sum of the winding voltage and its own output voltage, and after the rectifier is set, the diode or switch in the output unit needs to be , its withstand voltage only needs to be greater than the difference between the highest voltage of the same bus multi-output and its own voltage.

In one embodiment, taking a non-isolated power conversion circuit as an example, as shown in FIG. 2 , the power conversion circuit includes an inductor LP and a main switch Q1, and the output end of the power conversion circuit is connected in series with a synchronous switch Q7 Then connect each output unit in parallel. In another embodiment, taking an isolated power conversion circuit as an example, the power conversion circuit includes a transformer, the synchronous switch Q7 is connected in series with the secondary winding of the transformer and then output, and each output unit is connected in parallel to the transformer. The output terminals are connected in series, as shown in Figure 3.

Further optionally, the multi-channel output converter can also realize the reverse power supply function, so that when the input end of the power conversion circuit is not connected to the voltage, the reverse power supply module as the load can be used to supply the circuit through the transformer or the inductor. input power supply.

Exemplarily, the multi-output converter further includes a reverse power supply module, and the reverse power supply module includes a rechargeable component, as shown in FIG. 3 , in the isolated power conversion circuit, the rechargeable component in the reverse power supply module BAT is located in an output unit, wherein two ends of the rechargeable component BAT are respectively connected to two ends of the secondary winding of the transformer through switching transistors QF and QF1. When the rechargeable component BAT is used as a load, QOF and QOF1 can be controlled to be turned on, so as to realize the charging of the rechargeable component BAT; and when the rechargeable component BAT is discharged, QF and QF1 can be controlled to be turned on.

In another embodiment, in the non-isolated power conversion circuit, as shown in FIG. 4 , the two ends of the rechargeable component BAT in the reverse power supply module are respectively connected to the two ends of the inductor L through the switches QF and QF1. terminal, the rechargeable component BAT is connected to the output terminal of the power conversion circuit in series with the switch tube QOF. When the rechargeable component BAT is used as a load, QOF can be controlled to be turned on, and when the rechargeable component BAT is discharged, QF and QF1 can be controlled to be turned on.

It can be understood that the rechargeable component BAT may be a rechargeable battery, a power bank and other devices with charging and discharging functions. During use, for example, when the input terminal of the power conversion circuit is not connected to the input voltage, the switch tubes connected to both ends of the rechargeable component are turned on, so that the rechargeable component can be input to the power conversion circuit through the transformer or the inductor. reverse power supply.

In this embodiment, the diode in the output unit can be changed to a switch tube as required to reduce losses; and the switch tube connected in series with the output capacitor can be one of MOS tube, triode, thyristor, gallium nitride, etc. or several combinations.

For the above-mentioned power conversion circuit, in addition to the main switching tube Q1 and the main components such as transformers or inductors used to realize power conversion, it can also include but not limited to EMC components and safety components, etc., as well as set capacitors, For components such as optocouplers, of course, additional VCC startup circuits, voltage divider detection circuits, current limit detection circuits, etc. can be provided, and these functions can also be integrated into the chip.

For example, in order to achieve fast dynamic response, it is necessary to monitor the load connection of each output unit and the required load energy in real time. Further, the multi-output converter also includes an isolation feedback circuit and a multi-output controller. Demonstration Typically, the isolated feedback circuit includes a feedback unit and a plurality of sampling units with the same number of channels as the output units, that is, the sampling units correspond to the output units one-to-one. In one embodiment, as shown in FIG. 5 , the sampling unit of the first output unit may be formed by voltage dividing resistors R6A and R7A, and the same is true for other output branches.

In one embodiment, the input terminals of each sampling unit are respectively connected to the output capacitors in the corresponding output units, and the output terminals are all connected to a multi-channel output controller; further, the multi-channel output controller conducts a reference to the power conversion circuit through the feedback unit Voltage signal feedback.

If the multi-output converter is a bilateral feedback structure or a primary-side feedback structure, the feedback unit is the auxiliary winding of the transformer T1, that is, the voltage signal feedback is performed using the principle of transformer winding mutual inductance, such as the FB signal shown in Figure 5. Of course, the feedback unit may also be other devices, which are not limited here.

Or, if the multi-output converter is a secondary-side feedback architecture, usually, the secondary-side feedback architecture performs secondary-to-primary isolation feedback through an optocoupler. At this time, the feedback unit adopts an optocoupler for voltage signal feedback. . Exemplarily, as shown in FIG. 6 , the signal input end of the optocoupler U7 is connected to the multiplex output controller, and the signal output end is connected to the power conversion circuit.

Further, the power conversion circuit includes a transformer, and the secondary winding of the transformer also includes a center tap output terminal. If the high voltage and low voltage are divided according to the size of the output voltage, the above-mentioned at least two output units are divided into a high-voltage output unit and a low-voltage output unit. unit, each low-voltage output unit will be connected in parallel with the middle tap output end and an output end of the secondary winding, and each high-voltage output unit will be connected in parallel with one output end and the other output end of the secondary winding. It can be understood that the so-called high voltage and low voltage are relative terms, for example, 5V is a low voltage, and 20V can be called a high voltage. By putting high voltage and high voltage together, low voltage and voltage close together can reduce ripple current and switch loss.

The following description will be combined with some power conversion circuits. By applying multiple outputs to these power conversion circuits, and then using the corresponding dynamic distribution control method, not only the output of different voltages and variable voltage output can be realized, but also dynamic distribution technology can be used to achieve Greatly improve system efficiency and response speed.

Taking an active clamp flyback (ACF) circuit as an example, exemplarily, as shown in FIG. 3, the power conversion circuit mainly includes a transformer T1, a main switch Q1, an energy storage capacitor Vin, a clamp switch QA and Clamping capacitor C1, etc., in which both ends of the energy storage capacitor Vin are used to connect the power supply; the positive pole of the energy storage capacitor Vin is connected to one end of the primary winding of the transformer T1, and the other end of the primary winding T1 is connected to the main switch transistors Q1 and One end of the clamp switch QA, the other end of the main switch Q1 is connected to the negative electrode of the energy storage capacitor Vin; the other end of the clamp switch QA is connected to one end of the clamp capacitor C1, and the other end of the clamp capacitor C1 is connected to the energy storage capacitor Positive pole of Vin. The secondary side of the transformer T1 can adopt the above-mentioned multi-output design.

In another isolated power conversion circuit, the transformer includes a first primary winding and a second primary winding, and the power conversion circuit includes a first conversion unit and a second conversion unit, exemplarily, as shown in FIG. 7 As shown, the first conversion unit is located at both ends of the first primary winding, and the second conversion unit is located at both ends of the second primary winding; wherein, the first conversion unit includes a capacitor C1 and a switch tube QA1 connected in series; The conversion unit includes capacitors C1A and QA1A connected in series.

Further, the multi-output converter further includes: a half-wave symmetrical conversion circuit. Exemplarily, the half-wave symmetrical conversion circuit includes a first bridge arm and a second bridge arm, and each bridge arm is composed of two switches connected in series A tube is formed, wherein the node where the two switching tubes are connected in series is grounded. Exemplarily, as shown in FIG. 7 , the first bridge arm is composed of switch transistors Q1 and QD1, the second bridge arm is composed of switch transistors Q1A and QD1A, and one end of the first bridge arm is connected to the first primary winding and the first bridge arm. A connection node of the conversion unit, and the other end is used to connect one end of the AC power supply; at the same time, one end of the second bridge arm is connected to the second primary winding and a connection node of the second conversion unit, and the other end is used to connect the AC power supply. another side. It can be understood that the multi-channel output converter combines half-wave symmetrical transformation and multi-channel output, which can greatly improve the conversion efficiency and reduce the system loss.

Optionally, the multi-output converter further includes: a single-stage PFC conversion circuit. Exemplarily, as shown in FIG. 7 , the single-stage PFC conversion circuit includes two input diodes DP and DPA, a mains switch QP, Two branch switch tubes QP2 and QP2A, two branch diodes DP1 and DP2, and energy storage capacitor EC1P; wherein, the respective anodes of the two input diodes DP and DPA are respectively connected to the first primary winding and the second One end of the primary winding, the respective cathodes are connected to one end of the main circuit switch tube QP, and also to one end of the energy storage capacitor EC1P, and the other end of the energy storage capacitor EC1P is grounded; the other end of the main circuit switch tube QP is connected to the two One end of the branch switch tubes (QP2 and QP2A); and the other ends of the two branch switch tubes (QP2 and QP2A) are respectively connected in series with the anodes of the corresponding branch diodes (DP1 and DP2). The cathodes of the diodes (DP1 and DP2) are used to connect the two ends of the AC power supply, respectively.

In the multi-output converter of this embodiment, the output side of the converter is connected with the output capacitor by setting switches or diodes in series, and multiple series structures are arranged in parallel to form multi-output, and which channel needs energy When , for the controllable output unit, the corresponding switch tube is controlled to be turned on to directly absorb energy from the inductor or transformer that stores energy, and then provide energy for the load. The multi-channel output converter can realize such as 5V, 9V, Voltage output of different sizes such as 12V or 20V, in addition, through the dynamic control of the switch tube in the controllable output unit, variable voltage output can also be realized.

Example 2

Referring to FIGS. 1 and 8 , this embodiment provides a control method for a multi-output converter, which can be used to control the multi-output converter of the above-mentioned embodiment 1, thereby improving system conversion efficiency and dynamic loudness rate. Wait. Exemplarily, the control method of the multiple-output converter includes:

Step S100, according to the load energy required by the output unit of the corresponding circuit, distribute the energy stored by the transformer or the inductor in the power conversion circuit to the corresponding circuit for rated voltage or variable voltage output.

For a fixed output unit with only one diode in series, it is in a long-term conduction state, and the energy on the transformer or inductor will be automatically stored in its output capacitor. For a unidirectional controllable output unit or a bidirectional controllable output unit, during energy distribution, the switch tube can be controlled to be in an on state until the voltage of the output capacitor in the corresponding circuit reaches the required voltage or the energy of the converter When the release is completed, the switch tube in the corresponding circuit is controlled to be closed.

In an embodiment, for the above step S100, allocating the stored energy to the output unit of the corresponding channel includes: according to the load energy required by the output unit of the corresponding channel, changing the transformer or inductor in the power conversion circuit to one or more The energy stored over multiple cycles is distributed in a single way.

For example, for the energy stored in the transformer or the inductor after the main open tube is turned on for one or more consecutive times, it can be output to one channel according to the demand. In addition, the multi-channel output controller can redistribute one or more times according to the demand to transmit energy to other circuits in need, and for the output unit that does not need energy, it is not necessary to turn on its switch. For the ACF circuit with single-stage PFC, please refer to Fig. 5, (a) in Fig. 9 is the voltage waveform in the whole cycle of the common single output winding; and (b) the energy distribution of the whole cycle in this embodiment The waveform given to one output unit includes the control signals of the main switches, of which the high level is the on state and the low level is the off state. While (a) in FIG. 10 is the voltage waveform in one cycle of the common single-output winding; and (b) the waveform of the single-cycle energy allocated to the multi-output unit in this embodiment. Among them, if the ACF circuit with single-stage PFC also includes a half-wave symmetrical structure, as shown in FIG. 7 , there is the waveform of Q1A in (b) of FIG. 11 , and the waveforms of the switches Q1 and Q1A are the same.

In another embodiment, for the above step S100, allocating the stored energy to the output unit of the corresponding channel includes: sequentially allocating the energy stored by the transformer or the inductor in the power conversion circuit in one cycle to the loaded energy The desired output unit.

For example, when the main switch Q1 is turned on and stored in the transformer or inductor, according to the output voltage demand, the switches in different output units are turned on in turn to provide energy, and the waveform is shown in Figure 10. For the ACF circuit with single-stage PFC, (a) in Fig. 11 is the voltage waveform of the winding of a common single-output; and (b) the waveform of the single-cycle energy distribution to the multi-output unit in this embodiment, in In the energy distribution process, the intermittent mode is used to control the switch tube. Likewise, if the ACF circuit with a single-stage PFC also includes a half-wave symmetrical structure, as shown in FIG. 7 , there will be a waveform of Q1A in (b) of FIG. 11 .

It is worth noting that when the energy distribution of multiple outputs is performed, if one cycle is used to assign the control time of the main switch to each channel, in this way, when there are too many outputs, one cycle waits for a long time, resulting in It is not suitable for fast charging occasions with large output ripple voltage and current, poor dynamic response, or variable voltage and current. In this regard, this embodiment adopts a dynamic allocation method, which includes two types: method 1. By allocating the energy of one or more switching cycles to one output circuit that needs it, the one that has no load or does not need energy is not Distribute the energy; method 2, the energy of one switching cycle is divided into multiple channels, which is equivalent to that each channel can be divided into an increased frequency and a small amount of electricity. At this time, the output ripple of each channel will be greatly reduced, which can reduce the output capacitance. Volume and capacity, you can use capacitors with small volume and longevity; further, this refers to multiplexing, including one output, and you can obtain the energy stored in the converter by the main switch multiple times, that is, during a demagnetization period of this channel The energy of the converter can be obtained by opening the main switch tube many times.

Further, in order to improve the dynamic response speed and ripple requirements, etc., fast rotation and response can be achieved by increasing the switching frequency.

The following describes the control method of the multi-output converter using dynamic allocation in combination with some specific power conversion circuits.

Taking the primary side feedback architecture (PSR) as an example, exemplarily, the primary side feedback architecture includes a transformer, a main switch tube and a primary controller connected in sequence, wherein the primary controller is mainly used to control the main switch tube, and then control the circuit the output voltage. For the specific structure of the primary-side feedback architecture, reference may be made to published documents, which will not be described here.

In one embodiment, as shown in FIG. 12 , the control method for dynamic allocation includes:

In step S110, the highest output voltage is used as the reference voltage set in the primary winding in advance.

In step S120, the output voltage of the demagnetization process is detected according to a preset method, and the detected highest output voltage is fed back to the primary controller.

Step S130, the primary controller controls the main switch tube according to the actually detected highest output voltage and the reference voltage, and then adjusts the output voltage of the corresponding channel.

For example, if some output voltages are 5V, 9V and 20V, select the highest 20V as the reference voltage, and then control each sampling unit to sample the output voltages of these output units in a preset manner, so that the actual detected highest The output voltage is fed back to the primary side. Then, the primary controller compares it with the reference voltage of 20V to control the main switch. If the output voltage is low, the primary energy transfer will be increased. On the contrary, if the output voltage is high, the primary energy transfer will be reduced. Wherein, the preset mode may include, but is not limited to, continuous monitoring by the main loop, or high-frequency detection, or selecting a fixed time point during the demagnetization of the transformer to perform mutual inductance detection, and the like.

It can be understood that the first method is to use the highest voltage of all multiple output voltages as the reference voltage. When the reference does not take the highest voltage, for example, for the way of distributing primary energy in turn, in another embodiment, as shown in Fig. 13, the control method for dynamic allocation includes:

Step S210, setting a specified voltage as the reference voltage.

In step S220, the waveform voltage is fed back to the primary controller by detecting the waveform voltage of the transformer in a specified time period.

Step S230, the primary controller controls the main switch tube according to the feedback voltage and the reference voltage, and then adjusts the output voltage of the corresponding circuit.

For example, the detection of the winding waveform voltage can be performed at a fixed time point during the demagnetization of the transformer, and the detected single-channel reference voltage is compared with the set reference circuit to control the transfer of primary energy, for example, when the detected single-channel reference voltage is compared. When the reference voltage of the channel is not equal to the reference circuit, the output voltage of the corresponding channel is adjusted according to the voltage drop or rise signal.

Taking the secondary side feedback architecture (SSR) as an example, exemplarily, the secondary side feedback architecture includes a transformer, a main switch, a primary controller, a secondary controller and an optocoupler, which are connected in sequence, wherein the optocoupler has a The signal input terminal is connected to the secondary controller, and the signal output terminal is connected to the primary controller. For the specific structure of the secondary-side feedback architecture, reference may be made to published documents, which will not be described in detail here.

Exemplarily, during the control process of dynamic energy distribution, the method includes:

The secondary controller detects the output voltage of each output unit in real time, selects one of the outputs as the reference to feed back to the primary master, and selects one of the following methods for the reference: select the one with the highest voltage among the multiple outputs; or One way is fixed and the output of this way is provided with energy at the end, that is, energy is provided to this way after satisfying the other outputs; or the reference voltage is dynamically selected, that is, the reference voltage is dynamically selected from the current way that provides energy in real time. Further, according to the signal fed back by the reference, the required voltage or current signal is transmitted to the primary controller through the optocoupler; finally, the primary controller transmits the required voltage or current signal to the main switch tube according to the obtained secondary voltage or current signal. Control is performed to control the energy delivered by the transformer.

As an optional embodiment, if the multi-output converter adopts the structure shown in FIG. 3 , the control method of the existing ACF circuit is to continuously turn on the clamp switch after the demagnetization starts until the demagnetization is completed. Close after a while. In the control process of dynamic allocation in this embodiment, different control methods are used, as shown in FIG. 14 , which mainly includes the following steps:

Step S310, in the initial stage of demagnetization, when the winding voltage of the transformer is higher than the voltage of the clamping capacitor, the main switch is controlled to be turned on, and after the first preset voltage is reached, the main switch is controlled to be turned off to make the transformer output The circuit outputs energy.

Step S320, after the demagnetization is completed, when the winding voltage of the transformer drops to the voltage of the clamping capacitor, the clamping switch is controlled to be turned on so that the clamping capacitor outputs energy to the converter.

Step S330, after a preset time period, the clamp switch is turned off or when the voltage of the clamp capacitor is detected to drop to the second preset voltage, the clamp switch is controlled to be turned off, and when the flyback voltage of the winding reaches the valley bottom or the zero-point voltage When the control main switch is turned on again. Repeat the above steps.

Exemplarily, for the above-mentioned ACF circuit, this embodiment will use the discontinuous mode for control, by controlling the clamping switch to be turned on after the demagnetization is completed and the voltage condition is satisfied, and when the flyback voltage of the winding reaches the valley bottom or The main switch tube is turned on at the zero point, which not only recovers the leakage inductance energy, but also realizes the valley bottom or zero point conduction. It can be understood that the above control process is not only applicable to single-channel and multi-channel outputs, but also can realize valley bottom or zero-point conduction, which can greatly reduce the loss of the main switch tube. The above control methods can support SSR architecture, PSR architecture, DSR architecture, and the like.

Further, when the power conversion circuit includes a transformer and a main switch tube connected to the transformer, the input end of the power conversion circuit is also provided with an input capacitor, and for a multi-output converter including a bidirectionally controllable output unit, the method also include:

Controlling one or more of the two switches in the bidirectional controllable output unit in the output circuit is turned on, so as to release the electricity in the output capacitor in the corresponding circuit to the transformer; further, controlling the primary switch in the power conversion circuit The tube is turned on to store the energy in the transformer in the input capacitor to achieve bidirectional output.

It can be understood that the options for the multi-channel output converter in the above-mentioned Embodiment 1 are also applicable to this embodiment, so the description is not repeated here.

The control method of the multi-channel output converter in this embodiment controls the multi-channel output unit through dynamic distribution, and controls the switch tube of the corresponding channel to open when the channel needs energy, so as to directly absorb energy from the inductor or the transformer, Especially when a variable voltage output is required, the control method can realize the fast response output of the variable voltage, and for some that do not need energy, the switch on its branch is not turned on, which can maximize the utilization of energy resources.

The present application also provides a power supply device. Exemplarily, the power supply device includes the multi-channel output converter of the above-mentioned embodiment 1. Further, the power supply device can adopt the control method in the above-mentioned embodiment 2 to the multi-channel output converter. The converter performs multiple output control.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this. should be covered within the scope of protection of this application.

Claims

A control method for a multi-output converter, characterized in that the multi-output converter includes a power conversion circuit and an output circuit connected to the power conversion circuit, and the power conversion circuit includes a main switch tube and an output circuit connected to the power conversion circuit. The transformer or inductor connected to the main switch tube, the output circuit includes at least two output units, wherein each output unit includes an output capacitor, and at least one switch tube and/or diode, the at least one switch tube and/or a diode is connected in series with the output capacitor, the transformer or the inductor is used for connecting a power supply or an energy storage capacitor, and each of the output capacitors is respectively used for connecting a different load; the method includes:

According to the load energy required by the output unit of the corresponding circuit, the energy stored in the transformer or the inductor is distributed to the corresponding circuit for rated voltage or variable voltage output.
The control method according to claim 1, wherein the output unit is a fixed output unit, a unidirectional controllable output unit or a bidirectional controllable output unit, wherein the fixed output unit includes a The output capacitor is connected in series with a diode or a switch tube, the unidirectional controllable output unit includes a diode and a switch tube connected in series with the output capacitor, and the bidirectional controllable output unit includes a switch tube connected in series with the output capacitor. two switch tubes;

Wherein, during energy distribution, the switch tube in the unidirectional controllable output unit or the bidirectional controllable output unit is controlled to be in a conducting state until the voltage of the output capacitor in the corresponding circuit reaches the required voltage Or when the energy of the converter is released, the switch tube in the corresponding circuit is controlled to be turned off.
The control method according to claim 1 or 2, wherein the multi-output converter further comprises: a rectifier tube, wherein if the power conversion circuit adopts the transformer to store energy, the rectifier tube and the The secondary winding of the transformer is connected in series and then connected in parallel to each output unit; if the power conversion circuit adopts the inductance energy storage, the output end of the power conversion circuit is connected in parallel with the rectifier tube in parallel. the output unit;

The method further includes: rectifying the voltage output by the transformer or the inductor through the rectifier tube, and then outputting the voltage to the output unit of the corresponding channel.
The control method according to claim 3, wherein the multi-output converter further comprises: a reverse power supply module, wherein the reverse power supply module comprises a rechargeable component, wherein if the power conversion circuit adopts the The transformer stores energy, and the two ends of the rechargeable component located in the output unit are respectively connected to the two ends of the secondary winding through a switch tube; if the power conversion circuit adopts the inductance energy storage, it is located in the Two ends of the rechargeable component at the output end of the power conversion circuit are respectively connected to two ends of the inductor through a switch;

The method further includes: when the input terminal of the power conversion circuit is not connected to the input voltage, turning on the switch tube connected to the two ends of the rechargeable component, so that the rechargeable component passes through the transformer or the switch. The inductance back-powers the input of the power conversion circuit.
The control method according to claim 2, wherein, according to the load energy required by the output unit of the corresponding circuit, the energy stored in the transformer or the inductor in the power conversion circuit is distributed to the Describe the corresponding routes, including:

According to the load energy required by the output unit of the corresponding channel, the energy stored by the transformer or the inductor in the power conversion circuit in one or more cycles is allocated to a single channel;

Alternatively, the energy stored by the transformer or the inductor in the power conversion circuit in one cycle is sequentially distributed to the output units with load energy demand.
The control method according to claim 1, wherein the multi-output converter is a primary-side feedback architecture, and the primary-side feedback architecture includes a transformer, a main switch and a primary controller connected in sequence, and the primary The controller is used to control the main switch tube;

The method includes:

The output voltage of each output unit is detected in a preset manner, and the highest output voltage among the detected output voltages is fed back to the primary controller as a reference voltage, so that the primary controller can The reference voltage controls the main switch tube, and then adjusts the output voltage of the corresponding circuit;

Or, set a specified voltage as the reference voltage, detect the waveform voltage of the transformer in a specified period, and feed back the waveform voltage to the primary controller, so that the primary controller can make the feedback based on the feedback voltage and the primary controller. The reference voltage controls the main switch tube, thereby adjusting the output voltage of the corresponding circuit.
The control method according to claim 1, wherein the multi-output converter is a secondary-side feedback architecture, and the secondary-side feedback architecture comprises a transformer, a main switch, a primary controller, and a secondary connected sequentially. A controller and an optocoupler, wherein a signal input end of the optocoupler is connected to the secondary controller, and a signal output end is connected to the primary controller;

The secondary controller detects the output voltage of each output unit in real time, and selects one of the outputs as a reference to feed back to the primary master. The reference selection adopts one of the following methods: selecting the highest voltage among the multiple channels; Or choose one of them to fix; or dynamically select the reference voltage from the current circuit that provides energy; and then transmit the required voltage or current signal to the primary controller through the optocoupler according to the signal fed back by the reference, and the primary control The transformer controls the main switch tube according to the obtained secondary voltage or current signal, thereby controlling the energy transmitted by the transformer.
The control method according to claim 6 or 7, wherein the power conversion circuit further comprises a clamp switch tube and a clamp capacitor, wherein one end of the primary winding of the transformer is connected to the clamp capacitor. one end, the other end of the primary winding is respectively connected to one end of the main switch tube and the clamp switch tube, and the other end of the clamp switch tube is connected to the other end of the clamp capacitor; the method further include:

In the initial stage of demagnetization, when the winding voltage of the transformer is higher than the voltage of the clamping capacitor, the main switch is controlled to be turned on, and after reaching the first preset voltage, the main switch is controlled to be turned off so that the transformer outputs energy to the output circuit;

After the demagnetization is completed, when the winding voltage of the transformer drops to the voltage of the clamping capacitor, the clamping switch is controlled to be turned on, so that the clamping capacitor outputs energy to the converter;

After a preset time period, the clamp switch is turned off or when it is detected that the voltage of the clamp capacitor drops to a second preset voltage, the clamp switch is controlled to be turned off, and the flyback voltage of the winding reaches the valley bottom Or when the voltage is zero, the main switch tube is controlled to be turned on again.
The control method according to claim 2, wherein, if the power conversion circuit includes a transformer and a main switch tube connected to the transformer, and an input capacitor is provided at an input end of the power conversion circuit, the method further comprises: include:

Controlling two switches in one or more bidirectional controllable output units in the output circuit to conduct, so as to release the electricity in the output capacitor in the corresponding circuit to the transformer;

The primary switch in the power conversion circuit is controlled to be turned on, so as to store the energy in the transformer in the input capacitor to realize bidirectional output.
A multi-channel output converter, characterized in that it comprises: a power conversion circuit and an output circuit connected to the power conversion circuit, the power conversion circuit comprising a main switch tube and a transformer or an inductor connected to the main switch tube , the output circuit includes at least two output units;

Wherein, each output unit includes an output capacitor, and at least one switch tube and/or diode, the at least one switch tube and/or diode are connected in series with the output capacitor, and each of the output capacitors is used to connect different The transformer or the inductor is used to connect the power supply or the energy storage capacitor, and each of the output capacitors is respectively used to obtain the energy stored in the transformer or the inductor to provide the load to the load.