A multi-channel output converter and control method thereof

Abstract

The embodiment of the present application provides a multi-channel output converter and a control method thereof, wherein the multi-channel output converter includes: a power conversion circuit and an output circuit, wherein the power conversion circuit includes a transformer or an inductor, and 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 a diode, wherein the at least one switch tube and / or a diode is connected in series with the output capacitor, and each output capacitor is used to connect different loads, respectively, and the method includes: according to the load energy required by the output unit of the corresponding channel, the energy stored in the transformer or the inductor is distributed to the corresponding channel for rated voltage or variable voltage output. The technical solution connects the switch tube in series with the output capacitor at the output end of the converter to form a multi-channel output, and controls it by adopting a dynamic energy distribution method, so as to realize a fast response output of multiple different voltages or variable voltages, has a simple structure, and reduces system losses, etc.

Description

Technical Field

[0001] The present application relates to the technical field of power conversion, and in particular to a multi-channel output converter and a control method thereof. Background Art

[0002] In the prior art, when realizing multi-channel output, it is usually necessary to output different turn ratios through multiple windings on the transformer. Since the turn ratio of this circuit output is fixed, it cannot realize variable voltage output, and when the load between the multiple outputs is unbalanced, it will cause the voltage of some unloaded circuits to be artificially high. As for another method, the voltage is first increased and then decreased. The BUCK circuit is required in the process of voltage reduction, which will require an inductor to be set for each circuit to achieve voltage reduction, which not only takes up space, but also the two-stage conversion will increase the loss. Of course, there is another way, which is to use multiple transformers for multi-channel output. This method is efficient, but several transformers are required for several outputs, and one transformer can only provide one output. For example, a 65W transformer, when 5W is used for 5.1V output, the remaining 60W will be idle, resulting in a waste of resources. Summary of the invention

[0003] In view of this, in order to overcome the deficiencies in the prior art, the present application provides a multi-output converter and a control method thereof.

[0004] An embodiment of the present application provides a control method for a multi-channel output converter, wherein the multi-channel 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 and a transformer or an inductor connected to the main switch tube, and 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 a diode, wherein the at least one switch tube and / or a diode is connected in series to 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 different loads; the method includes:

[0005] According to the load energy required by the output unit of the corresponding path, the energy stored in the transformer or inductor is distributed to the corresponding path to output rated voltage or variable voltage.

[0006] 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 connected in series with the output capacitor, the unidirectional controllable output unit includes a diode and a switch connected in series with the output capacitor, and the bidirectional controllable output unit includes two switches connected in series with the output capacitor;

[0007] When energy distribution is performed, the switch tube in the unidirectional controllable output unit or the bidirectional controllable output unit is controlled to be in an on state until the voltage of the output capacitor in the corresponding path reaches the required voltage or the energy of the converter is released, and then the switch tube in the corresponding path is controlled to be turned off.

[0008] In some embodiments, the multi-channel output converter further includes: a rectifier tube, wherein, if the power conversion circuit adopts the transformer to store energy, the rectifier tube is connected in series with the secondary winding of the transformer and then connected in parallel to each output unit; if the power conversion circuit adopts the inductor to store energy, the output end of the power conversion circuit is connected in series with the rectifier tube and then connected in parallel to each output unit;

[0009] The method further includes: rectifying the voltage output by the transformer or the inductor through the rectifier tube and then outputting it to the output unit of the corresponding path.

[0010] In some embodiments, the multi-channel 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 energy storage, 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 inductor energy storage, the two ends of the rechargeable component located at the output end of the power conversion circuit are respectively connected to the two ends of the inductor through a switch tube;

[0011] The method also includes: when the input end 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 reversely supplies power to the input end of the power conversion circuit through the transformer or the inductor.

[0012] In some embodiments, allocating the energy stored in the transformer or inductor in the power conversion circuit to the corresponding path according to the load energy required by the output unit of the corresponding path includes:

[0013] The energy stored in the transformer or inductor in the power conversion circuit in one or more cycles is distributed in a single path according to the load energy required by the output unit of the corresponding path.

[0014] In some embodiments, allocating the energy stored in the transformer or inductor in the power conversion circuit to the corresponding path according to the load energy required by the output unit of the corresponding path includes:

[0015] The energy stored in the transformer or inductor in the power conversion circuit within one cycle is sequentially distributed to output units with load energy requirements.

[0016] In some embodiments, the multi-channel output converter is a primary feedback architecture, the primary feedback architecture includes a transformer, a main switch tube and a primary controller connected in sequence, the primary controller is used to control the main switch tube; the method includes:

[0017] The output voltage of each output unit is detected in a preset manner, and the highest output voltage among the detected multiple output voltages is fed back to the primary controller as a reference voltage, so that the primary controller controls the main switch tube according to the reference voltage, thereby adjusting the output voltage of the corresponding path.

[0018] In some embodiments, the multi-channel output converter is a primary feedback architecture, the primary feedback architecture includes a transformer, a main switch tube and a primary controller connected in sequence, the primary controller is used to control the main switch tube; the method includes:

[0019] A specified voltage is set as a reference voltage, the waveform voltage of the transformer in a specified period is detected, and the waveform voltage is fed back to the primary controller, so that the primary controller controls the main switch tube according to the feedback voltage and the reference voltage, thereby adjusting the output voltage of the corresponding path.

[0020] In some embodiments, the multi-channel output converter is a secondary-side feedback architecture, and the secondary-side feedback architecture includes a transformer, a main switch tube and a primary controller, and a secondary controller and a photoelectric coupler connected in sequence, wherein the signal input end of the photoelectric coupler is connected to the secondary controller, and the signal output end is connected to the primary controller; the method includes:

[0021] The secondary controller detects the output voltage of each output unit in real time, selects one of the outputs as a reference to feed back to the primary main control, and the reference selection adopts one of the following methods: selecting the highest voltage path among multiple paths; or selecting a fixed path; or dynamically selecting the reference voltage from the current path providing energy; then the required voltage or current signal is transmitted to the primary controller through the optocoupler according to the reference feedback signal, and the primary controller controls the main switch tube according to the obtained secondary voltage or current signal, thereby controlling the energy transmitted by the transformer.

[0022] In some embodiments, the power conversion circuit further includes a clamp switch tube and a clamp capacitor, wherein one end of the primary winding of the transformer is connected to one end of the clamp capacitor, 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 includes:

[0023] 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 tube is controlled to be turned on, and after reaching a first preset voltage, the main switch tube is controlled to be turned off so that the transformer outputs energy to the output circuit;

[0024] After demagnetization is completed, when the winding voltage of the transformer drops to the voltage of the clamping capacitor, the clamping switch tube is controlled to be turned on so that the clamping capacitor outputs energy to the converter;

[0025] After a preset time, the clamp switch tube is turned off or when it is detected that the voltage of the clamp capacitor drops to a second preset voltage, the clamp switch tube is controlled to be turned off, and when the flyback voltage of the winding reaches the bottom or is a zero voltage, the main switch tube is controlled to be turned on again.

[0026] In some embodiments, if the power conversion circuit includes a transformer and a main switch connected to the transformer, and an input capacitor is provided at the input end of the power conversion circuit, the method further includes:

[0027] Controlling two switch tubes in one or more bidirectional controllable output units in the output circuit to be turned on, so as to release the electricity in the output capacitor in the corresponding path to the transformer;

[0028] The primary switch tube 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 achieve bidirectional output.

[0029] The embodiment of the present application further provides 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 transformer or an inductor connected to the main switch tube, the output circuit comprising at least two output units;

[0030] Among them, each output unit includes an output capacitor and at least one switching tube and / or a diode, and the at least one switching tube and / or the diode is connected in series with the output capacitor, and each of the output capacitors is used to connect different loads, and 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 obtain the energy stored in the transformer or the inductor to provide it to the load.

[0031] 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;

[0032] Among them, 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, 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.

[0033] In some embodiments, the multi-output converter further includes: a rectifier tube;

[0034] If the power conversion circuit includes the transformer, the rectifier tube is connected in series with the secondary winding of the transformer and then output, and each output unit is connected in parallel to both ends of the output;

[0035] 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.

[0036] In some embodiments, the multi-output converter further includes: a reverse power supply module;

[0037] The reverse power supply module includes a rechargeable component, wherein if the power conversion circuit adopts the transformer to store energy, 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;

[0038] If the power conversion circuit adopts the inductor to store energy, the two ends of the rechargeable component located at the output end of the power conversion circuit are respectively connected to the two ends of the inductor through a switch tube.

[0039] The embodiments of the present application have the following beneficial effects:

[0040] The technical solution of the present application is to connect a switch tube or a diode in series with an output capacitor at the output end of a universal converter, and to form a multi-channel output by setting them in parallel according to actual needs. Through dynamic allocation control, the switch tube of the corresponding channel is turned on when energy is needed, so as to directly absorb energy from the inductor or transformer in the converter, thereby realizing a fast response output of multiple channels with different voltages or variable voltages. The structure is simple and the system loss is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1A first structural schematic diagram of a multi-channel output converter according to an embodiment of the present application is shown;

[0043] Figure 2 A schematic structural diagram of a non-isolated converter including a rectifier tube of a multi-channel output converter according to an embodiment of the present application is shown;

[0044] Figure 3 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 is shown;

[0045] Figure 4 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 is shown;

[0046] Figure 5 A schematic diagram showing the structure of a multi-channel output converter applied to a primary-side feedback architecture according to an embodiment of the present application is shown;

[0047] Figure 6 A schematic diagram showing the structure of a multi-channel output converter applied to a secondary-side feedback architecture according to an embodiment of the present application is shown;

[0048] Figure 7 A schematic diagram showing the structure of a multi-output converter including half-wave symmetrical transformation and single-stage PFC transformation in an embodiment of the present application is shown;

[0049] Figure 8 A flow chart showing a control method of a multi-output converter according to an embodiment of the present application is shown;

[0050] Fig. 9 A waveform diagram showing the distribution of a single output throughout a cycle of a control method for a multi-output converter according to an embodiment of the present application is shown;

[0051] Fig.10 A first waveform diagram of a single cycle distribution of multiple outputs in a control method of a multi-output converter according to an embodiment of the present application is shown;

[0052] Fig.11 A second waveform diagram of a single cycle distribution of multiple outputs in a control method of a multi-output converter according to an embodiment of the present application is shown;

[0053] Fig.12 A control flow chart of a control method for a multi-output converter according to an embodiment of the present application applied to a primary feedback architecture is shown;

[0054] Fig.13 A control flow chart of a control method for a multi-output converter according to an embodiment of the present application applied to a secondary-side feedback architecture is shown;

[0055] Fig.14A control flow chart of a control method for a multi-output converter according to an embodiment of the present application applied to an ACF circuit is shown. DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0057] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0058] Example 1

[0059] Please refer to Figure 1 , this 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 needs, etc.

[0060] Exemplarily, the multi-channel 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, and the output circuit includes at least two output units. It can be understood that the transformer or inductor is used to connect to the connected power supply or energy storage capacitor, and is combined with the on and off control of the main switch tube Q1 to store energy.

[0061] In this embodiment, the output circuit includes multiple output units, wherein each output unit includes an output capacitor and at least one switch tube and / or diode, and the at least one switch tube and / or diode is connected in series with the output capacitor. Each output capacitor is used to connect different loads.

[0062] Among them, 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 achieved as an example, the output unit can be divided into a unidirectional output unit and a bidirectional output unit, etc. Furthermore, the following types of output units can be obtained by combining different functions, such as a unidirectional fixed output unit, a bidirectional fixed output unit, a unidirectional controllable output unit, and a bidirectional controllable output unit, etc.

[0063] In one embodiment, Figure 1As shown, 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 tube; the unidirectional controllable output unit mainly includes a diode and a switch tube connected in series with the output capacitor, and the bidirectional controllable output unit mainly includes two switch tubes connected in series with the output capacitor.

[0064] It is understandable that users can select any combination of one or more outputs according to actual needs. For example, in situations where the highest voltage needs to be output for a long time and there is a long-term light load or loaded circuit, only one diode DOA or switch QOB is added to prevent backflow, such as Figure 1 Branches A and B are shown. For another example, for situations where the load is not long-term or a variable voltage output is required, a diode DOC can be added to the output capacitor and a switch tube QOC can be connected in series to achieve this, such as Figure 1 Branch C shown. For another example, when variable voltage output is required, or efficiency is high, or reverse reflux is required, two switch tubes QOD and QOD1 can be connected in series to achieve this. Figure 1 Branch D shown.

[0065] It is worth noting that for the above-mentioned types of output units, the structures of branches A and C can usually be used for small current circuits; while for large current circuits, such as fast charging, the structures of branches B and C can be preferred. It should be understood that for occasions where only one variable voltage output is required, only branch D consisting of two switch tubes in series can be selected to achieve it.

[0066] In this embodiment, the power conversion circuit is a general 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 inductor. Of course, the power conversion circuit can also be a forward converter or a flyback converter, or a converter of different architecture types such as primary feedback, secondary feedback, and bilateral feedback. It can be understood that the multi-channel output design can be applied to various converter architectures, and the structure of the power conversion circuit is not limited here.

[0067] Furthermore, the multi-channel output converter also includes a rectifier located at the output side of the power conversion circuit, for example, the rectifier can be a diode or a synchronous switch tube. The rectifier tube is used as a common rectifier tube to uniformly rectify the voltage output by the transformer or inductor before outputting it to each output unit, which can not only reduce costs, but also reduce the withstand voltage of the switch tube and diode in each output unit. This is because, when the rectifier tube does not exist, the diode or switch tube in each output needs to be greater than the sum of the winding voltage and its own output voltage, and after the rectifier tube is set, the withstand voltage of the diode or switch tube in the output unit only needs to be greater than the difference between the highest voltage of the multi-channel output of the same bus and its own voltage.

[0068] In one implementation, taking a non-isolated power conversion circuit as an example, Figure 2 As shown, the power conversion circuit includes an inductor LP and a main switch tube Q1, and the output end of the power conversion circuit is connected in series with a synchronous switch tube Q7 and then connected in parallel to each output unit. In another embodiment, taking an isolated power conversion circuit as an example, the power conversion circuit includes a transformer, and the synchronous switch tube Q7 is connected in series with the secondary winding of the transformer and then output, and each output unit is connected in parallel to both ends of the output after the series connection, as shown in FIG. Figure 3 shown.

[0069] Further optionally, the multi-output converter can also realize a reverse power supply function, so that when the input end of the power conversion circuit is not connected to a voltage, the reverse power supply module as a load can be used to supply power to the input end of the circuit through a transformer or an inductor.

[0070] Exemplarily, the multi-output converter further comprises a reverse power supply module, which comprises a rechargeable component, such as Figure 3 As shown, in the isolated power conversion circuit, the rechargeable component BAT in the reverse power supply module is located in an output unit, wherein the two ends of the rechargeable component BAT are connected to the two ends of the secondary winding of the transformer through switch tubes QF and QF1 respectively. When the rechargeable component BAT is used as a load, QOF and QOF1 can be controlled to be turned on 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.

[0071] In another embodiment, in a non-isolated power conversion circuit, such as Figure 4 As shown, the two ends of the rechargeable component BAT in the reverse power supply module are connected to the two ends of the inductor L through the switch tubes QF and QF1 respectively, and the rechargeable component BAT is connected in series with the switch tube QOF and then connected to the output end of the power conversion circuit. 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.

[0072] It can be understood that the rechargeable component BAT can be a device with charging and discharging functions such as a rechargeable battery, a power bank, etc. During use, for example, when the input end of the power conversion circuit is not connected to the input voltage, the switch tube connected to the two ends of the rechargeable component is turned on, so that the rechargeable component reversely supplies power to the input end of the power conversion circuit through a transformer or an inductor.

[0073] In this embodiment, the diode in the output unit can be replaced by a switch tube to reduce loss as needed; and the switch tube connected in series with the output capacitor can be one or a combination of MOS tube, triode, thyristor, gallium nitride, etc.

[0074] As for the above-mentioned power conversion circuit, in addition to the main components used to realize power conversion such as the main switch tube Q1 and the transformer or inductor, it can also include but not be limited to EMC components and safety components, as well as capacitors, photocouplers and other components set according to needs. Of course, VCC startup circuits, voltage divider detection circuits, current limiting detection circuits, etc. can also be additionally set, and these functions can also be integrated into the chip.

[0075] For example, in order to achieve fast dynamic response, it is necessary to monitor the load connection status of each output unit and the required load energy in real time. Furthermore, the multi-channel output converter also includes an isolation feedback circuit and a multi-channel output controller. Exemplarily, the isolation feedback circuit includes a feedback unit and a plurality of sampling units with the same number of output units, that is, the sampling units correspond to the output units one by one. In one embodiment, Figure 5 As shown, the sampling unit of the first output unit can be formed by voltage-dividing resistors R6A and R7A, and the same is true for other output branches.

[0076] In one embodiment, the input end of each sampling unit is respectively connected to the output capacitor in the corresponding output unit, and the output end is connected to the multi-channel output controller; further, the multi-channel output controller feeds back the reference voltage signal to the power conversion circuit through the feedback unit.

[0077] If the multi-channel output converter is a double-side 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 by using the mutual inductance principle of the transformer winding, such as Figure 5 Of course, the feedback unit can also be other devices, which is not limited here.

[0078] Alternatively, if the multi-channel output converter is a secondary-side feedback architecture, usually, the secondary-side feedback architecture uses a photocoupler to perform isolated feedback from the secondary to the primary. In this case, the feedback unit uses a photocoupler to perform voltage signal feedback. Figure 6As shown, the signal input end of the photoelectric coupler U7 is connected to the multi-channel output controller, and the signal output end is connected to the power conversion circuit.

[0079] Furthermore, the power conversion circuit includes a transformer, and the secondary winding of the transformer also includes an intermediate tap output terminal. If the high voltage and low voltage are divided according to the magnitude of the output voltage, the at least two output units are divided into high voltage output units and low voltage output units, then each low voltage output unit will be connected in parallel to the intermediate tap output terminal and one output terminal of the secondary winding, and each high voltage output unit will be connected in parallel to one output terminal and another output terminal of the secondary winding. It can be understood that the so-called high voltage and low voltage are relative. For example, 5V is low voltage, and 20V can be called high voltage. By putting high voltage and high voltage together, and low voltage and voltage close together, ripple current and switch tube loss can be reduced.

[0080] The following description is combined with some power conversion circuits. By applying multi-channel outputs to these power conversion circuits and then adopting corresponding dynamic allocation control methods, not only can the output of different voltages and variable voltage output be achieved, but the dynamic allocation technology can also be used to greatly improve the system efficiency, response speed, etc.

[0081] Taking an active clamp flyback (ACF) circuit as an example, for example, Figure 3 As shown, the power conversion circuit mainly includes a transformer T1, a main switch tube Q1, an energy storage capacitor Vin, a clamp switch tube QA and a clamp capacitor C1, etc., wherein the two ends of the energy storage capacitor Vin are used to connect to the power supply; the positive electrode 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 one end of the main switch tube Q1 and the clamp switch tube QA, and the other end of the main switch tube Q1 is connected to the negative electrode of the energy storage capacitor Vin; the other end of the clamp switch tube QA is connected to one end of the clamp capacitor C1, and the other end of the clamp capacitor C1 is connected to the positive electrode of the energy storage capacitor Vin. The secondary side of the transformer T1 can adopt the above-mentioned multi-channel output design.

[0082] 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. Figure 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 second conversion unit includes capacitors C1A and QA1A connected in series.

[0083] Furthermore, the multi-channel output converter further includes: a half-wave symmetrical conversion circuit, which exemplarily includes a first bridge arm and a second bridge arm, each bridge arm is composed of two switch tubes connected in series, wherein the node where the two switch tubes are connected in series is grounded. Figure 7 As shown, the first bridge arm is composed of switch tubes Q1 and QD1, and the second bridge arm is composed of switch tubes Q1A and QD1A. One end of the first bridge arm is connected to a connection node between the first primary winding and the first 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 a connection node between the second primary winding and the second conversion unit, and the other end is used to connect the other end of the AC power supply. It can be understood that the multi-channel output converter combines half-wave symmetrical conversion and multi-channel output, which can greatly improve conversion efficiency and reduce system losses.

[0084] Optionally, the multi-output converter further includes: a single-stage PFC conversion circuit, exemplarily, such as Figure 7 As shown, the single-stage PFC conversion circuit includes two input diodes DP and DPA, a main switch tube QP, two branch switch tubes QP2 and QP2A, two branch diodes DP1 and DP2, and an energy storage capacitor EC1P; wherein, the anodes of the two input diodes DP and DPA are respectively connected to one end of the first primary winding and the second primary winding, and the cathodes of the two input diodes DP and DPA are respectively connected to one end of the main switch tube QP and 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 switch tube QP is respectively connected to one end of the two branch switch tubes (QP2 and QP2A); and the other ends of the two branch switch tubes (QP2 and QP2A) are respectively connected in series to the anodes of the corresponding branch diodes (DP1 and DP2), and the cathodes of the two branch diodes (DP1 and DP2) are respectively used to connect the two ends of the AC power supply.

[0085] The multi-channel output converter of this embodiment forms multi-channel output by setting a switch tube or a diode in series with the output capacitor on the output side of the converter, and setting multiple series structures in parallel. When energy is needed in any channel, for the controllable output unit, the corresponding switch tube is controlled to open so that energy is directly absorbed from the inductor or transformer storing energy, thereby providing energy to the load. The multi-channel output converter can achieve voltage outputs of different sizes such as 5V, 9V, 12V or 20V. In addition, variable voltage output can also be achieved through dynamic control of the switch tube in the controllable output unit.

[0086] Example 2

[0087] Please refer to Figure 1 and 8This embodiment provides a control method for a multi-channel output converter, which can be used to control the multi-channel output of the multi-channel output converter of the above embodiment 1, thereby improving the system conversion efficiency and dynamic loudness rate. Exemplarily, the control method for the multi-channel output converter includes:

[0088] Step S100, according to the load energy required by the output unit of the corresponding path, the energy stored in the transformer or inductor in the power conversion circuit is distributed to the corresponding path to output a rated voltage or a variable voltage.

[0089] 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, when distributing energy, its switch tube can be controlled to be in a conduction state until the voltage of the output capacitor in the corresponding path reaches the required voltage or the converter energy is released, and then the switch tube in the corresponding path is controlled to be closed.

[0090] In one embodiment, for the above step S100, the stored energy is distributed to the output unit of the corresponding path, including: according to the load energy required by the output unit of the corresponding path, the energy stored in the transformer or inductor in the power conversion circuit in one or more cycles is distributed in a single path.

[0091] For example, the energy stored in the transformer or inductor by one or more main switch tubes can be output to one output according to demand. In addition, the multi-channel output controller can also redistribute the energy to other circuits in need one or more times according to demand, and for output units that do not need energy, their switch tubes do not need to be turned on. For ACF circuits with single-stage PFC, see Figure 5 , Fig. 9 (a) is the voltage waveform of the winding of a common single-channel output in the whole cycle; and (b) is the waveform of the energy distribution to one output unit in the whole cycle of this embodiment, including the control signals of several main switch tubes, where the high level is the on state and the low level is the off state. Fig.10 (a) is the voltage waveform of a winding of a common single-channel output within one cycle; and (b) is the waveform of energy distribution to multiple output units in a single cycle of this embodiment. If the ACF circuit with single-stage PFC also includes a half-wave symmetrical structure, such as Figure 7 As shown, there is Fig.11 In (b) of the waveform of Q1A, the waveforms of the switching tubes Q1 and Q1A are the same.

[0092] In another embodiment, for the above step S100, the stored energy is distributed to the output units of the corresponding paths, including: the energy stored in the transformer or inductor in the power conversion circuit in one cycle can be distributed in sequence to the output units with load energy requirements.

[0093] For example, when the main switch tube Q1 is turned on, the energy stored in the transformer or inductor is turned on in turn according to the output voltage requirement to provide energy. The waveform is as follows: Fig.10 As shown. For the ACF circuit with single-stage PFC, Fig.11 (a) is the voltage waveform of the winding of a common single-channel output; and (b) is the waveform of the energy distribution of a single cycle to the multi-channel output unit in this embodiment. In the energy distribution process, the discontinuous mode is used to control the switch tube. Similarly, if the ACF circuit with single-stage PFC also includes a half-wave symmetrical structure, such as Figure 7 As shown, there is Fig.11 The waveform of Q1A in (b).

[0094] It is worth noting that when distributing energy to multiple outputs, if the control time of the main switch is reused once for each output in a cycle, this method will have a long waiting time in a cycle when there are too many outputs, resulting in large output ripple voltage and current, poor dynamic response, or it is not suitable for fast charging occasions with variable voltage and current. In this regard, this embodiment adopts a dynamic distribution method, which includes two types: method 1, by distributing the energy of one or more switching cycles to an output circuit that needs it, the energy is not distributed to the circuit that is not loaded or does not need energy; method 2, the energy of a switching cycle is distributed to multiple channels separately, which is equivalent to increasing the frequency and reducing the amount of electricity distributed to each channel. At this time, the output ripple of each channel will be greatly reduced, which can reduce the volume and capacity of the output capacitor, and can use small-volume and long-life capacitors; further, the distribution to multiple channels here also includes that one output can obtain the energy stored in the converter by the main switch multiple times, that is, during a demagnetization period, this channel can open the main switch tube multiple times to obtain the energy of the converter.

[0095] Furthermore, in order to improve the dynamic response speed and ripple requirements, etc., fast rotation and response can be achieved by increasing the switching frequency.

[0096] The following describes the control method of the multi-channel output converter using dynamic allocation in conjunction with some specific power conversion circuits.

[0097] Taking the primary side feedback architecture (PSR) as an example, 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, thereby controlling the output voltage of the circuit. The specific structure of the primary side feedback architecture can be found in the published literature, and will not be described in detail here.

[0098] In one embodiment, Fig.12 As shown, the control method for dynamic allocation includes:

[0099] Step S110, the highest output voltage is used as a reference voltage set in the primary winding in advance.

[0100] Step S120 , detecting the output voltage during the demagnetization process according to a preset method, and feeding back the detected highest output voltage to the primary controller.

[0101] In step S130 , the primary controller controls the main switch tube according to the actually detected highest output voltage and the reference voltage, thereby adjusting the output voltage of the corresponding path.

[0102] For example, if the output voltages are 5V, 9V and 20V, the highest 20V is selected as the reference voltage, and then, the output voltages of these output units are sampled respectively by controlling each sampling unit in a preset manner, so as to feed back the actually detected highest output voltage to the primary side, and then, the primary controller compares it with the reference voltage 20V to control the main switch tube, and if the output voltage is low, the primary energy transfer is increased, and vice versa, if the output voltage is high, the primary energy transfer is reduced. The preset method 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 period of the transformer through mutual inductance detection, etc.

[0103] It can be understood that the first method is to use the highest voltage of all the multiple output voltages as the reference voltage. When the reference is not the highest voltage, for example, for the method of allocating primary energy in turn, in another embodiment, Fig.13 As shown, the control method for dynamic allocation includes:

[0104] Step S210, setting a designated voltage as a reference voltage.

[0105] Step S220 , by detecting the waveform voltage of the transformer in a specified period of time, the waveform voltage is fed back to the primary controller.

[0106] In step S230 , the primary controller controls the main switch tube according to the feedback voltage and the reference voltage, thereby adjusting the output voltage of the corresponding path.

[0107] For example, the winding waveform voltage can be detected at a fixed time point during the demagnetization period of the transformer, and the detected single-channel reference voltage can be compared with the set reference circuit to control the transfer of primary energy. For example, when the detected single-channel reference voltage is not equal to the reference circuit, the output voltage of the corresponding channel is adjusted according to the voltage drop or rise signal.

[0108] Taking the secondary side feedback architecture (SSR) as an example, the secondary side feedback architecture includes a transformer, a main switch tube and a primary controller, as well as a secondary controller and an optocoupler 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 specific structure of the secondary side feedback architecture can be found in the published literature, and will not be described in detail here.

[0109] Exemplarily, during the control process of dynamic energy distribution, the method includes:

[0110] The secondary controller detects the output voltage of each output unit in real time, selects one of the outputs as a reference to feed back to the primary main control, and the reference is selected in one of the following ways: select the one with the highest voltage among the multiple outputs; or select a fixed one and provide energy to this output at the end, that is, provide energy to this output after satisfying the other outputs; or dynamically select the reference voltage, that is, dynamically select the reference voltage from the current output that provides energy in real time. Then, according to the reference feedback signal, the required voltage or current signal is transmitted to the primary controller through the photocoupler; finally, the primary controller controls the main switch tube according to the obtained secondary voltage or current signal, thereby controlling the energy transmitted by the transformer.

[0111] As an optional embodiment, if the multi-channel output converter adopts Figure 3 In the structure shown, the control method of the existing ACF circuit is to continuously turn on the clamp switch tube after the demagnetization starts, and then turn it off after a period of time after the demagnetization is completed. In the control process of dynamic allocation in this embodiment, different control methods are adopted, such as Fig.14 As shown, it mainly includes the following steps:

[0112] 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 tube is controlled to be turned on, and after reaching a first preset voltage, the main switch tube is controlled to be turned off so that the transformer outputs energy to the output circuit.

[0113] Step S320: After demagnetization is completed, when the winding voltage of the transformer drops to the voltage of the clamping capacitor, the clamping switch tube is controlled to be turned on so that the clamping capacitor outputs energy to the converter.

[0114] Step S330, after a preset time, the clamp switch tube is turned off or when it is detected that the voltage of the clamp capacitor drops to a second preset voltage, the clamp switch tube is controlled to be turned off, and when the winding flyback voltage reaches the valley bottom or is a zero voltage, the main switch tube is controlled to be turned on again. Repeat the above steps.

[0115] Exemplarily, for the above-mentioned ACF circuit, this embodiment will adopt the intermittent mode for control, by controlling the clamp switch tube to conduct only when the demagnetization is completed and the voltage condition is met, and turning on the main switch tube when the flyback voltage of the winding reaches the valley or zero point, so that the leakage inductance energy is recovered and the valley or zero point conduction is achieved. It can be understood that the above control process is not only applicable to single-channel and multi-channel outputs, but also can achieve valley or zero point conduction, which can greatly reduce the loss of the main switch tube. The above control method can support SSR architecture, PSR architecture and DSR architecture, etc.

[0116] Furthermore, when the power conversion circuit includes a transformer and a main switch connected to the transformer, the input end of the power conversion circuit is also provided with an input capacitor. For a multi-channel output converter including a bidirectional controllable output unit, the method further includes:

[0117] The two switch tubes in one or more bidirectional controllable output units in the output circuit are controlled to be turned on to release the electricity in the output capacitor in the corresponding path to the transformer; further, the primary switch tube in the power conversion circuit is controlled to be turned on to store the energy in the transformer in the input capacitor, thereby realizing bidirectional output.

[0118] It can be understood that the options regarding the multi-channel output converter in the above-mentioned embodiment 1 are also applicable to this embodiment, so they will not be described repeatedly here.

[0119] The control method of the multi-channel output converter of the present embodiment controls the multi-channel output unit through a dynamic allocation method, and controls the switch tube of the corresponding channel to open when energy is needed, so as to directly absorb energy from the inductor or transformer. Especially when variable voltage output is required, the control method can realize fast response output of variable voltage, and for some branches that do not need energy, the switch tube on the branch is not opened, so as to realize the maximum utilization of energy resources.

[0120] 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 of the above-mentioned embodiment 2 to perform multi-channel output control on the multi-channel output converter.

[0121] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A control method for a multi-output converter, characterized in that: The multi-channel output converter comprises a power conversion circuit and an output circuit connected to the power conversion circuit, the power conversion circuit comprises a main switch tube and a transformer or an inductor connected to the main switch tube, the output circuit comprises at least two output units, wherein each output unit comprises an output capacitor and at least one switch tube and / or a 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 to connect a power supply or an energy storage capacitor, and each output capacitor is used to connect different loads respectively; the method comprises: Distribute the energy stored in the transformer or inductor in the power conversion circuit in one or more cycles in a single path according to the load energy required by the output unit of the corresponding path; Alternatively, the energy stored in the transformer or inductor in the power conversion circuit in one cycle is sequentially distributed to output units with load energy demand; Among them, when energy distribution is performed, if the output unit includes a switch tube, the switch tube in the output unit is controlled to be in an on state until the voltage of the output capacitor in the corresponding path reaches the required voltage or the energy of the converter is released, and then the switch tube is controlled to be turned off.

2. The control method according to claim 1, characterized in that: 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 connected in series with the output capacitor, 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.

3. The control method according to claim 1 or 2, characterized in that: The multi-channel output converter further includes: a rectifier tube, wherein, if the power conversion circuit adopts the transformer to store energy, the rectifier tube is connected in series with the secondary winding of the transformer and then connected in parallel to each output unit; if the power conversion circuit adopts the inductor to store energy, the output end of the power conversion circuit is connected in series with the rectifier tube and then connected in parallel to each output unit; The method further includes: rectifying the voltage output by the transformer or the inductor through the rectifier tube and then outputting it to the output unit of the corresponding path.

4. The control method according to claim 3, characterized in that: The multi-channel 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 energy storage, 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 inductor energy storage, the two ends of the rechargeable component located at the output end of the power conversion circuit are respectively connected to the two ends of the inductor through a switch tube; The method also includes: when the input end 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 reversely supplies power to the input end of the power conversion circuit through the transformer or the inductor.

5. The control method according to claim 1, characterized in that: The multi-channel output converter is a primary feedback architecture, which 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 comprises: Detecting the output voltage of each output unit according to a preset method, and feeding back the highest output voltage among the detected multiple output voltages as a reference voltage to the primary controller, so that the primary controller controls the main switch tube according to the reference voltage, thereby adjusting the output voltage of the corresponding path; Alternatively, a specified voltage is set as a reference voltage, the waveform voltage of the transformer in a specified period is detected, and the waveform voltage is fed back to the primary controller, so that the primary controller controls the main switch tube according to the feedback voltage and the reference voltage, thereby adjusting the output voltage of the corresponding path.

6. The control method according to claim 1, characterized in that: The multi-channel output converter is a secondary-side feedback architecture, which includes a transformer, a main switch tube and a primary controller, a secondary controller and a photoelectric coupler connected in sequence, wherein the signal input end of the photoelectric coupler is connected to the secondary controller, and the signal output end is connected to the primary controller; The method comprises: The secondary controller detects the output voltage of each output unit in real time, selects one of the outputs as a reference to feed back to the primary main control, and the reference selection adopts one of the following methods: selecting the highest voltage path among multiple paths; or selecting a fixed path; or dynamically selecting the reference voltage from the current path providing energy; then the required voltage or current signal is transmitted to the primary controller through the optocoupler according to the reference feedback signal, and the primary controller controls the main switch tube according to the obtained secondary voltage or current signal, thereby controlling the energy transmitted by the transformer.

7. The control method according to claim 5 or 6, characterized in that: The power conversion circuit further includes a clamp switch tube and a clamp capacitor, wherein one end of the primary winding of the transformer is connected to one end of the clamp capacitor, 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 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 tube is controlled to be turned on, and after reaching a first preset voltage, the main switch tube is controlled to be turned off so that the transformer outputs energy to the output circuit; After demagnetization is completed, when the winding voltage of the transformer drops to the voltage of the clamping capacitor, the clamping switch tube is controlled to be turned on so that the clamping capacitor outputs energy to the converter; After a preset time, the clamp switch tube is turned off or when it is detected that the voltage of the clamp capacitor drops to a second preset voltage, the clamp switch tube is controlled to be turned off, and when the flyback voltage of the winding reaches the bottom or is a zero voltage, the main switch tube is controlled to be turned on again.

8. The control method according to claim 2, characterized in that: If the power conversion circuit includes a transformer and a main switch 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 switch tubes in one or more bidirectional controllable output units in the output circuit to be turned on, so as to release the electricity in the output capacitor in the corresponding path to the transformer; The primary switch tube 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 achieve bidirectional output.

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