Multi-output switching power supply and control method thereof

Abstract

The invention provides a multi-output switching power supply and a control method thereof, the multi-output switching power supply comprises a primary power loop, an isolation transformer, a secondary power loop, N output branches and a control device, the primary power loop is connected with a primary winding of the isolation transformer; the primary power loop is connected with a primary winding of the isolation transformer, the secondary power loop is connected with a secondary winding of the isolation transformer, the secondary power loop is further connected with the N output branches, and the control device is connected with the primary power loop, the secondary power loop and the N output branches and used for controlling the primary power loop according to feedback signals of the N output branches. And the total energy transmitted from the primary winding to the secondary winding of the isolation transformer is adjusted, and the N output branches are controlled to be conducted in a time-sharing manner in a follow current period of the secondary power loop, so that the output of multiple voltages is realized with relatively low cost and complexity and relatively high efficiency.

Description

Technical Field

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

[0002] In the field of power electronics, isolated switching power supplies are core components for power conversion and supply, and their performance and efficiency are crucial to the operation of the entire electronic system.

[0003] The traditional switching power supply architecture mainly includes a primary power circuit, an isolation transformer and a secondary power circuit, wherein the secondary power circuit is directly connected to the load to achieve stable output of electrical energy.

[0004] However, with the diversification of electronic equipment functions, the demand for multi-channel output of switching power supplies is increasing. As a multi-channel output switching power supply, multi-channel output is achieved by selecting an isolation transformer with multi-level secondary windings and combining it with the control of the switch tube. However, the switching circuit has the problem of poor cross-regulation rate, and the structure is complex and the cost is high. As another multi-channel output switching power supply, which includes multiple DC-DC modules, the overall conversion efficiency of the system will be reduced due to the addition of a voltage conversion circuit. Summary of the invention

[0005] The embodiment of the present application provides a multi-channel output switching power supply and a control method thereof, so as to enable the multi-channel output switching circuit to achieve the effect of low cost, low complexity and high efficiency multi-channel voltage output.

[0006] Some embodiments of the present application provide a multi-output switching power supply, including: a primary power circuit, an isolation transformer, a secondary power circuit, N output branches, and a control device;

[0007] The primary power circuit is connected to the primary winding of the isolation transformer; the secondary power circuit is connected to the secondary winding of the isolation transformer, and the secondary power circuit is also connected to N output branches, where N is a natural number greater than 1;

[0008] The control device is connected to the primary power circuit, the secondary power circuit and the N output branches;

[0009] The control device is used to adjust the total energy transmitted from the primary winding of the isolation transformer to the secondary winding according to the feedback signals of the N output branches, and control the N output branches to be turned on in time-sharing manner within the freewheeling period of the secondary power circuit.

[0010] In some embodiments, the isolation transformer includes a secondary winding, and the input ends of the N output branches are all connected to the first end of the secondary winding;

[0011] The secondary power circuit includes a second transistor or a diode;

[0012] Wherein, the first end of the second transistor is connected to the second end of the secondary winding, the second end of the second transistor is grounded, and the control end of the second transistor is connected to the control device;

[0013] The cathode of the diode is connected to the second end of the secondary winding, and the anode of the diode is grounded.

[0014] In some embodiments, the isolation transformer includes N secondary windings, and the N secondary windings correspond to the output branches one by one; the input end of the output branch is connected to the first end of the corresponding secondary winding;

[0015] The secondary power circuit includes N second transistors or N diodes; the N secondary windings correspond to the N second transistors one by one, and the N secondary windings correspond to the N diodes one by one;

[0016] A first end of each second transistor is connected to a second end of a corresponding secondary winding, a second end of the second transistor is grounded, and a control end of each second transistor is connected to a control device;

[0017] The cathode of each diode is connected to the second end of the corresponding secondary winding, and the anode of the diode is grounded.

[0018] In some embodiments, the output branch includes an output switch and a capacitor;

[0019] The first end of the output switch serves as the input end of the output branch, the second end of the output switch is used to connect the load, the control end of the output switch is connected to the control device, the first plate of the capacitor is connected to the second end of the output switch, and the second plate of the capacitor is grounded.

[0020] In some embodiments, the primary power loop includes a first transistor;

[0021] The first end of the first transistor is connected to the second end of the primary winding, the second end of the first transistor is grounded, and the control end of the first transistor is connected to the control device.

[0022] In some embodiments, the control device includes: a primary controller, an isolation module, and a secondary controller;

[0023] The secondary controller is used to generate total energy feedback information according to the N feedback signals, and to generate N second control signals according to any N-1 feedback signals among the N feedback signals and the collected signal of the secondary power loop;

[0024] The N second control signals correspond to the N output branches one by one, and each second control signal is used to control the corresponding output branch to be turned on or off;

[0025] The isolation module is connected with the secondary controller and the primary controller, and is used for transmitting the total energy feedback information to the primary controller; the primary controller is used for generating a first control signal according to the total energy feedback information.

[0026] In some embodiments, the secondary controller includes N operational amplifiers, a channel selection module, and an output switch control module;

[0027] The first input end of each operational amplifier is connected to the output end of the corresponding output branch, the second input end of each operational amplifier is used to receive the reference output voltage of the output branch, and the output end of each operational amplifier is connected to the channel selection module;

[0028] The channel selection module is used to select N-1 feedback signals from N feedback signals for output, and the output switch control module generates a second control signal based on the N-1 feedback signals and the collected signal of the secondary power loop.

[0029] In some embodiments, the secondary controller includes a total energy control module;

[0030] The output end of each operational amplifier is connected to the total energy control module;

[0031] The total energy control module is used to receive feedback signals output by N operational amplifiers, and to generate and output total energy feedback information according to the N feedback signals.

[0032] In some embodiments, the isolation transformer includes a secondary winding, the switching power supply includes two output branches, and the secondary power circuit is connected to the two output branches through an output bus;

[0033] Accordingly, the collected signal includes the output bus voltage and the drain-source voltage of the second transistor;

[0034] The output switch control module includes: a signal recognition module, a signal processing module and a logic processing module;

[0035] The signal recognition module is used to obtain a conduction indication signal of the first transistor according to the output bus voltage and the drain-source voltage of the second transistor;

[0036] The signal processing module is used to generate a volt-second modulation signal according to the output bus voltage, the drain-source voltage of the second transistor and a preset modulation rule;

[0037] The logic processing module is connected to the signal identification module, the signal processing module and the channel selection module, and is used to generate two second control signals according to the conduction indication signal, the volt-second modulation signal and the feedback signal output by the channel selection module.

[0038] In some embodiments, the logic processing module includes: a comparator, an inverter, an AND gate circuit, a first SR trigger, and a second SR trigger;

[0039] The first input terminal of the comparator is connected to the output terminal of the channel selection module, and the second input terminal is connected to the signal processing module;

[0040] The input end of the inverter is connected to the signal identification module, the output end of the inverter is connected to the first input end of the AND gate circuit, the second input end of the AND gate circuit is connected to the output end of the comparator, the output of the AND gate circuit is connected to the second end of the first SR trigger and the first end of the second SR trigger, the output of the signal identification module is connected to the first end of the first SR trigger and the second end of the second SR trigger, and the output end of the first SR trigger and the output end of the second SR trigger both output a second control signal.

[0041] Some embodiments of the present application also provide a control method for a multi-output switching power supply, the method comprising:

[0042] According to the feedback signals of the N output branches, the total energy transmitted from the primary winding of the isolation transformer to the secondary winding is adjusted, and the N output branches are controlled to be turned on in time-sharing manner within the freewheeling period of the secondary power circuit.

[0043] In some embodiments, according to the feedback signals of the N output branches, the total energy transmitted from the primary winding of the isolation transformer to the secondary winding is adjusted, and the N output branches are controlled to be turned on in time-sharing manner during the freewheeling period of the secondary power circuit, specifically including:

[0044] Generating total energy feedback information according to the N feedback signals, and generating a first control signal according to the total energy feedback information;

[0045] N second control signals are generated according to any N-1 feedback signals among the N feedback signals and the collected signal of the secondary power loop.

[0046] In some embodiments, generating total energy feedback information according to N feedback signals specifically includes:

[0047] The signal amplitudes of the N feedback signals are summed up as total energy feedback information.

[0048] The multi-output switching power supply and control method thereof provided in the embodiments of the present application, by setting multiple output branches to be connected to the secondary power circuit, controls the total energy transmitted from the primary winding of the isolation transformer to the secondary winding according to the feedback signals of the N output branches, and controls the N output branches to be turned on in time during the freewheeling period of the secondary power circuit by the control device, so as to adjust the amount of energy received by each output branch from the isolation transformer and realize the power distribution among the N output branches, thereby realizing the output of multiple voltages with lower cost and complexity and higher efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0050] Figure 1 A schematic diagram of the architecture of a switching power supply;

[0051] Figure 2 is a schematic diagram of another switching power supply architecture;

[0052] Figure 3 A schematic diagram of the structure of a switching power supply provided in some embodiments of the present application;

[0053] Figure 4 A schematic diagram of the structure of a switching power supply provided in some embodiments of the present application;

[0054] Figure 5 A schematic diagram of the structure of an output switch control module provided in some embodiments of the present application;

[0055] Figure 6 A timing diagram of a logic processing module provided in some embodiments of the present application;

[0056] Figure 7 A schematic diagram of the structure of a logic processing module provided in some embodiments of the present application;

[0057] Figure 8 A timing diagram of a logic processing module provided for some other embodiments of the present application.

[0058] Reference numerals:

[0059] 100-primary power circuit; T-isolation transformer; 200-secondary power circuit; 310-output branch;

[0060] 410-primary controller; 420-isolation module; 430-secondary controller; 431-operational amplifier; 432-total energy control module; 433-channel selection module; 434-output switch control module;

[0061] Vds-drain-source voltage; Vbus-bus voltage; Vcs-volt-second modulation signal; Vcs1-first volt-second modulation sub-signal; Vcs2-second volt-second modulation sub-signal; Drv-conduction indication signal;

[0062] 510-signal identification module; 520-signal processing module; 530-logic processing module;

[0063] Q1-first transistor; Q2-second transistor; M1-first switch tube; FBt-total energy feedback information;

[0064] 531 - comparator; 532 - inverter; 533 - AND gate circuit; 534 - first SR trigger; 535 - second SR trigger.

[0065] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0066] Here, exemplary embodiments will be described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application.

[0067] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the feature. In the description of the present application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0068] Figure 1 It is a structural diagram of a switching power supply, such as Figure 1 As shown, the switching power supply includes a primary power circuit, an isolation transformer, a secondary power circuit and two capacitors.

[0069] Among them, the primary power circuit includes a first switch tube M1, which is connected to the primary winding of the isolation transformer, and the primary winding also receives an external power supply Vin. By controlling the on and off of the first switch tube M1, the external power supply Vin charges and stores energy in the primary winding. The secondary power circuit includes two second switch tubes. The secondary winding of the isolation transformer is provided with three terminals, the first terminal is connected to the first end of the first second switch tube M21, the second end of the first second switch tube M21 is connected to the first output end Vo1 of the switching power supply, the second terminal is connected to the second second switch tube M22, the second end of the second second switch tube M22 is connected to the second output end Vo2 of the switching power supply, and the third terminal is grounded. The first output end Vo1 is connected to the first capacitor C11, and the second output end Vo2 is connected to the second capacitor C12.

[0070] When the switching power supply is working, the first switch tube M1 is turned on, the two second switch tubes are turned off, and the external power supply charges the primary winding to store energy. Then the first switch tube M1 is turned off, the two second switch tubes M2 are turned on at the same time, and the secondary winding charges the first capacitor C11 and the second capacitor C12.

[0071] However, the voltage of one of the two output ends can only be adjusted in proportion to the voltage of the other output end, and the proportion depends on the turns ratio of the winding, which makes the two output ends have a problem of poor cross-regulation rate. In addition, this solution increases the complexity of the transformer structure, which will significantly increase the volume and cost of the entire system.

[0072] Figure 2 It is a structural diagram of a switching power supply. Figure 2 Switching power supply structure and Figure 1 The difference in the structure of the switching power supply is that the secondary power circuit includes a second switch tube M2 and an output bus capacitor C0, and the switching power supply also includes two DC-DC circuits, each of which is connected to the output end of a switching power supply, and multiple outputs are generated through the voltage conversion of the DC-DC circuit. Since the voltage of each output end can be adjusted separately, there is no problem of cross-regulation rate. And the isolation transformer has fewer secondary windings, which can reduce the size of the switching power supply. However, each independently controlled DC-DC circuit increases the complexity of the overall circuit, and due to the addition of a primary voltage conversion circuit, the overall conversion efficiency of the system will be reduced.

[0073] Figure 3 A schematic diagram of the structure of a switching power supply provided in some embodiments of the present application, Figure 4 This is a schematic diagram of the structure of a switching power supply provided in some embodiments of the present application. Figure 3 and Figure 4 An embodiment of the present application provides a switching power supply, which includes a primary power circuit 100, an isolation transformer T, a secondary power circuit 200, N output branches 310 and a control device.

[0074] The primary power circuit 100 is connected to the primary winding of the isolation transformer T, the secondary power circuit 200 is connected to the output of the isolation transformer T, and the secondary power circuit 200 is also connected to N output branches 310, where N is a natural number greater than 1.

[0075] The control device is connected to the primary power circuit 100 , the secondary power circuit 200 and the N output branches 310 .

[0076] The control device is used to adjust the total energy transmitted from the primary winding of the isolation transformer to the secondary winding according to the feedback signals of the N output branches 310, and control the N output branches 310 to be turned on in time during the freewheeling period of the secondary power circuit.

[0077] Specifically, the primary power circuit 100 is also used to connect to an external power source Vin, and the external power source is used to store energy in the primary winding of the isolation transformer through the primary power circuit.

[0078] In other embodiments, a first transistor Q1 is provided in the primary power circuit 100, and the turning on and off of the first transistor Q1 controls the closing and opening of the charging path between the external power supply Vin and the primary winding of the isolation transformer T, thereby realizing the control of the energy storage of the primary winding of the isolation transformer T.

[0079] The feedback signal of each output branch 310 is used to feedback the energy required by each output branch 310. If the sum of the feedback signals of all output branches 310 indicates that the total energy required by all output branches 310 increases, the total energy transmitted from the primary winding of the isolation transformer to the secondary winding is increased. If the sum of the feedback signals of all output branches 310 indicates that the total energy required by all output branches 310 decreases, the total energy transmitted from the primary winding of the isolation transformer to the secondary winding is reduced.

[0080] Among them, time-sharing conduction means that only one output branch 310 is turned on at the same time, which can adjust the amount of energy received by each output branch 310 from the isolation transformer and realize the energy distribution among N output branches 310, thereby stabilizing the output voltage of the output branch 310.

[0081] More specifically, when distributing energy to the N output branches, if the feedback signal of a certain output branch indicates that the energy of the output branch 310 needs to be increased, the conduction time of the output branch 310 is increased. If the feedback signal of a certain output branch indicates that the energy of the output branch 310 needs to be reduced, the conduction time of the output branch 310 is reduced.

[0082] In the above technical solution, multiple output branches 310 are connected to the secondary power circuit 200, and the total energy transmitted from the primary winding of the isolation transformer to the secondary winding is controlled according to N feedback signals to meet the total energy required by each output port. The control device controls the N output branches 310 to be turned on in time-sharing during the freewheeling period of the secondary power circuit to achieve energy distribution between the N output branches 310, thereby achieving a stable output voltage of the output branch 310.

[0083] In some embodiments, Figure 3 As shown, the isolation transformer T includes a secondary winding, and the secondary power circuit 200 includes a second transistor Q2.

[0084] The first end of the second transistor Q2 is connected to the second end of the secondary winding of the isolation transformer T, the second end of the second transistor Q2 is grounded, the first end of the secondary winding of the isolation transformer T is connected to the input end of the N output branches 310, and the control end of the second transistor Q2 is connected to the control device.

[0085] When any output branch is turned on, the secondary winding, the output branch and the second transistor Q2 form a freewheeling loop, and the secondary winding transfers energy to the turned-on output branch.

[0086] In other embodiments, the isolation transformer T includes a secondary winding, and the secondary power circuit 200 includes a diode. The cathode of the diode is connected to the second end of the secondary winding of the isolation transformer T, the anode of the diode is grounded, and the first end of the secondary winding of the isolation transformer T is connected to the input end of the N output branches 310. When any output branch is turned on, the secondary winding, the turned-on output branch and the diode form a freewheeling circuit, and the secondary winding transmits energy to the turned-on output branch.

[0087] In some embodiments, Figure 4 As shown, the isolation transformer T includes N secondary windings, the secondary power circuit 200 includes N second transistors, the N secondary windings correspond to the N second transistors one-to-one, and the N secondary windings correspond to the N output branches 310 one-to-one.

[0088] The first end of the secondary winding of each isolation transformer T is connected to the input end of the corresponding output branch 310, the first end of each second transistor is connected to the second end of the corresponding secondary winding, the second end of the second transistor is grounded, and the control end of each second transistor is connected to the control device.

[0089] More specifically, the N secondary windings are labeled as the 1st secondary winding, the 2nd secondary winding, ..., the Nth secondary winding, the N output branches are labeled as the 1st output branch, the 2nd output branch, ..., the Nth output branch, and the N second transistors Q2 are labeled as the 1st second transistor Q21, the 2nd second transistor Q22, ..., the Nth second transistor Q2N.

[0090] The first end of the first secondary winding is connected to the input end of the first output branch, the first end of the first second transistor Q21 is connected to the second end of the first secondary winding, the second end of the first second transistor Q21 is grounded, and the control end of the first second transistor Q21 is connected to the control device.

[0091] The first end of the second secondary winding is connected to the input end of the second output branch, the first end of the second second transistor Q22 is connected to the second end of the second secondary winding, the second end of the second second transistor Q22 is grounded, and the control end of the second second transistor Q22 is connected to the control device.

[0092] And so on.

[0093] The first end of the Nth secondary winding is connected to the input end of the Nth output branch, the first end of the Nth second transistor Q2N is connected to the second end of the Nth secondary winding, the second end of the Nth second transistor Q2N is grounded, and the control end of the Nth second transistor Q2N is connected to the control device.

[0094] When the i-th output branch is turned on, the i-th secondary winding, the i-th output branch and the i-th second transistor Q2i form a freewheeling loop.

[0095] In other embodiments, the isolation transformer T includes N secondary windings, the secondary power circuit 200 includes N diodes, the N secondary windings correspond to the N diodes one-to-one, and the N secondary windings correspond to the N output branches 310 one-to-one.

[0096] The first end of each secondary winding is connected to the input end of the corresponding output branch 310, the cathode of each diode is connected to the second end of the corresponding secondary winding, and the anode of each diode is grounded. When any output branch is turned on, the turned-on output branch, the corresponding secondary winding and the corresponding diode form a freewheeling loop, and the secondary winding transfers energy to the turned-on output branch.

[0097] In some embodiments, continue to refer to Figure 3 and Figure 4 Each output branch 310 includes an output switch and a capacitor, one plate of the capacitor is grounded, and the other plate is connected to the second end of the output switch. The first end of the output switch serves as the input end of the output branch 310, the second end of the output switch is used to connect the load, and the control end of the output switch is connected to the control device.

[0098] The output switch is turned on or off under the control of the second control signal output by the control device, so as to realize the turning on or off of the output branch 310. When the output switch is turned on, the secondary winding charges the capacitor, and when the output switch is turned off, the secondary winding stops charging the capacitor. When a load is connected to the output branch 310, the capacitor continues to supply power to the load.

[0099] refer to Figure 3 and Figure 4 The first output branch 310 includes a first output switch S1 and a first capacitor C1, one plate of the first capacitor C1 is grounded, and the other plate is connected to the second end of the first output switch S1, the first end of the first output switch S1 serves as the input end of the first output branch 310, the second end of the first output switch S1 is used to connect to a load, and the control end of the first output switch S1 is connected to the control device.

[0100] By analogy, the Nth output branch 310 includes the Nth output switch SN and the Nth capacitor CN, one plate of the Nth capacitor CN is grounded, and the other plate is connected to the second end of the Nth output switch SN, the first end of the Nth output switch SN serves as the input end of the Nth output branch 310, the second end of the Nth output switch SN is used to connect to the load, and the control end of the Nth output switch SN is connected to the control device.

[0101] In some embodiments, the second control signal can control the on-time of the output switch, and the longer the on-time is, the more energy is allocated to the output branch, and the shorter the on-time is, the smaller the energy is allocated to the output branch.

[0102] In some embodiments, continue to refer to Figure 3 and Figure 4 The primary power circuit includes a first transistor Q1, a first end of the first transistor Q1 is connected to the second end of the primary winding of the isolation transformer T, a second end of the first transistor Q1 is grounded, and a control end of the first transistor Q1 is connected to the control device.

[0103] The control device is used to generate a first control signal according to the feedback signals of the N output branches 310, and the first control signal is used to control the conduction time and conduction frequency of the first transistor Q1. The conduction time determines the charging time of the primary winding in the isolation transformer T, thereby determining the energy storage size of the primary winding in the isolation transformer T, so that the energy transmission size of the primary power circuit 100 to the secondary power circuit 200 can be adjusted.

[0104] In some embodiments, continue to refer to Figure 3 and Figure 4 The control device includes a primary controller 410, an isolation module 420 and a secondary controller 430. The secondary controller 430 is connected to each output branch 310 to obtain a feedback signal of each output branch 310. The secondary controller 430 is also connected to the secondary power circuit 200 to obtain a collection signal of the secondary power circuit 200.

[0105] The secondary controller 430 is used to generate N second control signals based on any (N-1) feedback signals among the N feedback signals and the collected signal of the secondary power circuit 200. The N second control signals correspond one-to-one to the N output branches 310, and each second control signal is used to control the output branch 310 to be turned on or off.

[0106] The secondary controller 430 is also connected to the isolation module 420, and the isolation module 420 is connected to the primary controller 410. The secondary controller 430 is used to generate total energy feedback information FBt according to the feedback signals of the N output branches 310, and send the total energy feedback information FBt to the isolation module 420, and the isolation module 420 is used to transmit the total energy feedback information FBt to the primary controller 410, and the primary controller 410 is used to generate a first control signal according to the total energy feedback information FBt.

[0107] In some embodiments, the isolation module 420 may be one of the following: a magnetic isolation module 420 , a capacitive isolation module 420 , and an optical coupling isolation module 420 .

[0108] In the above technical solution, since the control device needs to output the second control signal to the output branch 310 close to the secondary power circuit 200, and also needs to output the first control signal to the primary power circuit 100, the voltage levels between the primary power circuit 100 and the secondary power circuit 200 are different. By setting the architecture of the primary controller 410, the isolation module 420 and the secondary controller 430, the isolation module 420 electrically isolates the signal of the primary controller 410 and the signal of the secondary controller 430 to ensure the safe operation of the switching power supply.

[0109] In some embodiments, continue to refer to Figure 3 The secondary controller 430 includes N operational amplifiers 431 , a total energy control module 432 , a channel selection module 433 and an output switch control module 434 .

[0110] The first input terminal of each operational amplifier 431 is connected to the output terminal of the corresponding output branch 310, the second input terminal of each operational amplifier 431 is used to receive the reference output voltage of the output branch 310, and the output terminal of each operational amplifier 431 is connected to the total energy control module 432 and the channel selection module 433.

[0111] The total energy control module 432 is used to receive feedback signals output by the N operational amplifiers 431, and generate and output total energy feedback information FBt according to the N feedback signals.

[0112] The channel selection module 433 selects (N−1) feedback signals to output from the N feedback signals, and the output switch control module 434 generates N second control signals based on the (N−1) feedback signals and the collected signal of the secondary power loop 200 .

[0113] Among them, the first input terminal of the operational amplifier 431 is used to receive the voltage of the output terminal of the corresponding output branch 310, and the second input terminal of the operational amplifier 431 is used to receive the reference output voltage of the corresponding output branch 310. The operational amplifier 431 performs a difference operation on the voltage of the output terminal of the output branch 310 and the reference output voltage and then amplifies it to obtain a feedback signal of the output branch 310.

[0114] In some embodiments, the total energy control module 432 uses the sum of the N feedback signals as the total energy feedback information FBt. In other embodiments, the feedback signal with the maximum value among the N feedback signals is used as the total energy feedback information FBt.

[0115] More specifically, the output switch control module 434 may generate a volt-second modulation signal Vcs according to a preset modulation rule, and generate N second control signals according to the (N-1) feedback signals and the volt-second modulation signal Vcs.

[0116] The working process of the output switch control module 434 is described below by taking a switching power supply with two outputs as an example.

[0117] like Figure 5 As shown, the collected signals of the secondary power circuit 200 include the output bus voltage Vbus and the drain-source voltage Vds of the second transistor Q2 . The output switch control module includes a signal identification module 510 , a signal processing module 520 and a logic processing module 530 .

[0118] The signal recognition module 510 is used to receive the output bus voltage Vbus and the drain-source voltage Vds of the second transistor Q2, and generate a conduction indication signal Drv of the first transistor Q1 according to the output bus voltage Vbus and the drain-source voltage Vds of the second transistor Q2.

[0119] The signal processing module 520 is used to receive the output bus voltage Vbus and the drain-source voltage Vds of the second transistor Q2, and generate a volt-second modulation signal Vcs according to the output bus voltage Vbus, the drain-source voltage Vds of the second transistor Q2 and a preset modulation rule.

[0120] The logic processing module 530 is connected to the signal identification module 510 , the signal processing module 520 and the channel selection module 433 , and is used to generate two second control signals according to the conduction indication signal Drv, the volt-second modulation signal Vcs and the feedback signal output by the channel selection module 433 .

[0121] refer to Figure 3 and Figure 4When the second transistor Q2 is turned off, the drain-source voltage Vds of the second transistor Q2 is the sum of the output bus voltage Vbus and the voltage on the secondary winding. When the second transistor Q2 is turned on, the drain-source voltage Vds of the second transistor Q2 is the on-state voltage drop of the second transistor Q2.

[0122] In some embodiments, the logic identification module 510 is specifically used to compare the drain-source voltage Vds of the second transistor Q2 with the output bus voltage Vbus, and generate the first transistor Q1 conduction indication signal Drv in combination with the voltage change rate of the drain-source voltage Vds.

[0123] If the drain-source voltage Vds of the second transistor Q2 is greater than the output bus voltage Vbus, and the absolute value of the voltage change rate of the drain-source voltage Vds of the second transistor Q2 is greater than the preset threshold, it means that the second transistor Q2 is turned off, the first transistor Q1 is turned on, and the conduction indication signal Drv is a high level. If the drain-source voltage Vds of the second transistor Q2 is less than the output bus voltage Vbus, it means that the first transistor Q1 is turned off, and the conduction indication signal Drv is a low level.

[0124] The signal processing module 520 can modulate the volt-second modulation signal Vcs into various forms according to preset modulation rules. The channel selection module 433 can also output any feedback signal, so the control concept of the present invention has various specific implementation methods, including but not limited to the following design schemes.

[0125] As an implementation of the output switch control module 434, the signal processing module, the channel selection module and the logic processing module may be designed as follows:

[0126] (1) The signal processing module 520 obtains the volt-second modulation signal Vcs according to the following modulation rule. When the first transistor Q1 is turned on and the second transistor Q2 is turned off, the volt-second modulation signal Vcs starts to rise from 0 volts. When the first transistor Q1 is turned off and the second transistor Q2 is turned on, that is, during the freewheeling period of the secondary power circuit, the volt-second modulation signal Vcs starts to decrease from the maximum value to 0 volts, wherein the rising and falling slopes of the volt-second modulation signal Vcs are proportional to the absolute value of the difference between the drain-source voltage Vds of the second transistor and the bus voltage Vbus.

[0127] (2) The channel selection module 433 selects the feedback signal output of the second output branch 310, and allows the first output branch 310 to be turned on first and the second output branch 310 to be turned on later.

[0128] (3) The logic processing module 530 can output two second control signals D1 and D2 according to the first truth table shown in Table 1, where D1 is the control signal of the first output branch and D2 is the control signal of the second output branch.

[0129] Table 1 First truth table

[0130] Drv FB2>Vcs D1 D2 0 0 Keep original state Keep original state 0 1 0 1 1 0 1 0 1 1 1 0

[0131] Figure 6 A timing diagram of a logic processing module provided in some embodiments of the present application, such as Figure 6 As shown:

[0132] In the stage from time t0 to time t1, the first control signal Qc1 is at a high level, the first transistor Q1 is turned on, the third control signal Qc3 is at a low level, and the second transistor Q2 is turned off. Since the second transistor Q2 is turned off, the drain-source voltage Vds of the second transistor Q2 is greater than the output bus voltage Vbus, and the voltage change slope of the drain-source voltage Vds of the second transistor Q2 at time t0 meets the judgment threshold, so the conduction indication signal Drv is at a high level. This stage is the charging process of the primary winding, and the volt-second modulation signal Vcs starts to rise from 0 volts. Referring to the above first truth table, since the conduction indication signal Drv is at a high level, the first second control signal D1 is at a high level, and the second second control signal D2 is at a low level. In this way, during the conduction period of the first transistor Q1, the first output branch 310 is turned on first, and the second output branch 310 is turned on later.

[0133] In the period from time t1 to time t3, the first control signal Qc1 is at a low level, the first transistor Q1 is turned off, the third control signal Qc3 is at a high level, and the second transistor Q2 is turned on. Since the second transistor Q2 is turned on, the drain-source voltage Vds of the second transistor Q2 is less than the output bus voltage Vbus, and the conduction indication signal Drv is at a low level.

[0134] The stage from time t1 to time t3 can be divided into the stage from time t1 to time t2 and the stage from time t2 to time t3.

[0135] From time t1 to time t2, the feedback signal FB2 of the second output branch 310 is less than the volt-second modulation signal Vcs. Referring to the first truth table, the two second control signals output by the logic processing module 530 maintain their original states, the first second control signal D1 is high level, and the second second control signal D2 is low level. The first output branch 310 is turned on, the second output branch 310 is turned off, and energy is transmitted to the load connected to the first output branch 310.

[0136] In the period from time t2 to time t3, the feedback signal FB2 of the second output branch 310 is greater than the volt-second modulation signal Vcs. Referring to the first truth table, the first second control signal D1 is at a low level, and the second second control signal D2 is at a high level. The first output branch 310 is disconnected, the second output branch 310 is turned on, and energy is transmitted to the load connected to the second output branch 310.

[0137] In the stage from time t3 to time t4, the first control signal Qc1 is at a low level, the first transistor Q1 is turned off, the third control signal Qc3 is at a low level, and the second transistor Q2 is turned off. Compared with the stage from time t0 to time t1, the voltage change slope of the drain-source voltage Vds of the second transistor Q2 does not meet the judgment threshold, and the conduction indication signal Drv is at a low level. After time t3, the freewheeling cycle of the secondary power circuit ends, the volt-second modulation signal Vcs continues to be 0 volts, and the feedback signal FB2 of the second output branch 310 is greater than the volt-second modulation signal Vcs. Referring to the above first truth table, the first second control signal D1 is at a low level, and the second second control signal D2 is at a high level. The first output branch 310 is disconnected, and the second output branch 310 is turned on.

[0138] At time t4, the first control signal Qc1 changes to a high level, the third control signal Qc3 changes to a low level, the first transistor Q1 is turned on, and the next cycle begins.

[0139] In the above embodiment, when the load connected to the second output branch 310 increases and the second output branch 310 needs to output more energy, the feedback signal FB2 of the second output branch 310 increases, the duration of the second second control signal being at a high level becomes longer, the conduction time of the second output branch 310 becomes longer, and the second output branch 310 can obtain more energy, thereby stabilizing the output voltage of the second output branch 310.

[0140] When the load connected to the second output branch 310 is reduced and the second output branch 310 needs to output less energy, the feedback signal FB2 of the second output branch 310 decreases, the duration of the second second control signal being at a high level becomes shorter, the conduction time of the second output branch 310 becomes shorter, and the second output branch 310 obtains less energy, thereby stabilizing the output voltage of the second output branch 310.

[0141] When the first output branch 310 needs more energy, the feedback signal FB1 corresponding to the first output branch 310 increases, and the total energy feedback information FBt indicates that more energy needs to be transferred. The energy transmitted from the primary winding of the isolation transformer to the secondary winding becomes larger, and the first output branch 310 obtains more energy, so that the output voltage of the first output branch 310 can be stabilized.

[0142] On the contrary, when the first output branch 310 needs less energy, the feedback signal FB1 corresponding to the first output branch 310 decreases, and the total energy feedback information FBt indicates that less energy needs to be transferred, the energy transmitted from the primary winding of the isolation transformer to the secondary winding becomes smaller, and the first output branch 310 obtains less energy, so that the output voltage of the first output branch 310 can be stabilized.

[0143] The logic processing module 530 is designed based on the above truth table, such as Figure 7 As shown, the logic processing module 530 includes: a comparator 531 , an inverter 532 , an AND gate circuit 533 , a first SR trigger 534 and a second SR trigger 535 .

[0144] The first input end of the comparator 531 is connected to the output end of the channel selection module 433, the second input end is connected to the output of the signal processing module 520, the input end of the inverter 532 is connected to the signal identification module 510, the output end of the inverter 532 is connected to the first input end of the AND gate circuit 533, the second input end of the AND gate circuit 533 is connected to the output end of the comparator 531, the output of the AND gate circuit 533 is connected to the second end of the first SR trigger 534 and the first end of the second SR trigger 535, the output of the signal identification module 510 is connected to the first end of the first SR trigger 534 and the second end of the second SR trigger 535, and the output end of the first SR trigger 534 and the output end of the second SR trigger 535 both output a second control signal.

[0145] As another implementation of the output switch control module 434, the signal processing module, the channel selection module and the logic processing module may be designed as follows:

[0146] (1) The signal processing module 520 obtains the volt-second modulation signal Vcs according to the following modulation rule. During the conduction period of the first transistor Q1, the first volt-second modulation sub-signal starts to rise from 0 volts, and the second volt-second modulation sub-signal is 0 volts. After the primary winding of the isolation transformer T is charged, the second transistor Q2 is turned on, and the secondary winding of the isolation transformer T is discharged through the secondary power circuit 200. The first volt-second modulation sub-signal remains unchanged, and the second volt-second modulation sub-signal starts to rise from 0 volts to the same as the first volt-second modulation sub-signal, and then the second volt-second modulation sub-signal decreases. When the discharge of the secondary winding is completed, the first volt-second modulation sub-signal and the second volt-second modulation sub-signal are both 0 volts. Among them, the change slope of the first volt-second modulation sub-signal is proportional to the absolute value of the difference between the drain-source voltage Vds of the second transistor and the bus voltage Vbus, and the change slope of the second volt-second modulation sub-signal is proportional to the absolute value of the difference between the drain-source voltage Vds of the second transistor and the bus voltage Vbus.

[0147] (2) The channel selection module 433 selects the feedback signal output of the second output branch 310 and turns on the second output branch 310 first and then the first output branch 310 .

[0148] (3) The logic processing module 530 can output two second control signals D1 and D2 according to the second truth table shown in Table 2, where D1 is the control signal of the first output branch and D2 is the control signal of the second output branch.

[0149] Table 2 Second truth table

[0150] Drv FB2>Vcs2 D1 D2 0 0 1 0 0 1 Keep original state Keep original state 1 0 0 1 1 1 0 1

[0151] Figure 8 A timing diagram of a logic processing module provided in some embodiments of the present application, such as Figure 8 As shown:

[0152] In the period from time t0 to time t1, the first control signal Qc1 is at a high level, the first transistor Q1 is turned on, the third control signal Qc3 is at a low level, and the second transistor Q2 is turned off. The second transistor Q2 is turned off, the drain-source voltage Vds of the second transistor Q2 is greater than the output bus voltage Vbus, the voltage change slope of the drain-source voltage Vds of the second transistor Q2 meets the judgment threshold, and the conduction indication signal Drv is at a high level. This stage is the charging process of the primary winding. At this time, the first volt-second modulation sub-signal Vcs1 starts to rise from 0 volts, and the second volt-second modulation sub-signal Vcs2 remains unchanged. Since the conduction indication signal Drv is at a high level, the first second control signal D1 is at a low level, and the second second control signal D2 is at a high level, so that the second output branch 310 is turned on and the first output branch 310 is turned off.

[0153] In the stage from time t1 to time t3, the first control signal Qc1 is at a low level, the first transistor Q1 is turned off, the third control signal Qc3 is at a high level, and the second transistor Q2 is turned on. Since the second transistor Q2 is turned on, the drain-source voltage Vds of the second transistor Q2 is less than the output bus voltage Vbus, the conduction indication signal Drv is at a low level, and the freewheeling period of the secondary power circuit is entered.

[0154] In the period from time t1 to time t2, the feedback signal FB2 of the second output branch 310 is greater than the second volt-second modulation sub-signal Vcs2, the first second control signal D1 and the second second control signal D2 maintain their original states, and the first output branch 310 and the second output branch 310 maintain the states at time t0 and time t1, that is, the second output branch 310 is turned on, the first output branch 310 is turned off, and energy is transmitted to the load connected to the second output branch 310.

[0155] In the period from time t2 to time t3, the feedback signal FB2 of the second output branch 310 is less than the second volt-second modulation sub-signal Vcs2, the first second control signal D1 is at a high level, and the second second control signal D2 is at a low level, controlling the first output branch 310 to be turned on and the second output branch 310 to be turned off, and energy is transmitted to the load connected to the first output branch 310.

[0156] In the stage from time t3 to time t4, the first control signal Qc1 is at a low level, the first transistor Q1 is turned off, the third control signal Qc3 is at a low level, and the second transistor Q2 is turned off. Compared with the stage from time t0 to time t1, after time t3, the voltage change slope of the drain-source voltage Vds of the second transistor Q2 does not meet the judgment threshold, and the conduction indication signal Drv is at a low level.

[0157] In the period from time t3 to time t4, the conduction indication signal Drv is at a low level, the feedback signal FB2 of the second output branch 310 is greater than the second volt-second modulation sub-signal Vcs2, and the first second control signal D1 and the second second control signal D2 maintain their original states. The first output branch 310 continues to conduct the secondary power circuit 200, and the second output branch 310 is disconnected from the secondary power circuit 200.

[0158] At time t4, the first control signal becomes high level, the third control signal is low level, the first transistor Q1 is turned on, and the next cycle begins.

[0159] In the above embodiment, when the load connected to the second output branch 310 increases and the second output branch 310 needs to output more energy, the feedback signal FB2 of the second output branch 310 increases, the time t2 is delayed, the duration of the second second control signal being at a high level becomes longer, the conduction time of the second output branch 310 becomes longer, and the second output branch 310 can obtain more energy.

[0160] When the load connected to the second output branch 310 is reduced and the second output branch 310 needs to output less energy, the feedback signal FB2 of the second output branch 310 is reduced, the time t2 is advanced, the duration of the second second control signal being at a high level becomes shorter, the conduction time of the second output branch 310 becomes shorter, and the second output branch 310 can obtain less energy.

[0161] When the first output branch 310 needs more energy, the feedback signal FB1 corresponding to the first output branch 310 increases, and the total energy feedback information FBt indicates that more energy needs to be transferred, the energy transferred from the primary winding of the isolation transformer to the secondary winding increases, and the first output branch 310 obtains more energy.

[0162] On the contrary, when the first output branch 310 needs less energy, the feedback signal FB1 corresponding to the first output branch 310 decreases, and the total energy feedback information FBt indicates that less energy needs to be transferred, the primary winding of the isolation transformer transfers less energy to the secondary winding, and the first output branch 310 obtains less energy.

[0163] The structure of the logic processing module 530 can be designed based on the second truth table in Table 2 above, which will not be further illustrated here.

[0164] It should be noted here that the volt-second modulation signal Vcs can be any periodic signal with the same switching frequency as the switching power supply. The volt-second modulation signal Vcs can be a triangle wave or a sawtooth wave, and there is no limitation here. The absolute value of the slope of the volt-second modulation signal Vcs is proportional to the absolute value of the difference between the drain-source voltage Vds of the second transistor and the bus voltage Vbus.

[0165] The channel selection module 433 can output the feedback signal output of any output branch 310 , and can achieve stabilization of the output voltages of multiple output branches 310 .

[0166] In different control implementations, the output selection of the channel selection module 433 is shown in Table 3:

[0167] Table 3

[0168]

[0169] Some embodiments of the present application also provide a control method for a multi-output switching power supply, a primary power circuit, an isolation transformer, a secondary power circuit, N output branches and a control device, the method comprising:

[0170] According to the feedback signals of the N output branches, the total energy transmitted from the primary winding of the isolation transformer to the secondary winding is adjusted, and the N output branches are controlled to be turned on in time-sharing manner within the freewheeling period of the secondary power circuit.

[0171] In some embodiments, according to the feedback signals of the N output branches, the total energy transmitted from the primary winding of the isolation transformer to the secondary winding is adjusted, and the N output branches are controlled to be turned on in time-sharing manner during the freewheeling period of the secondary power circuit, specifically including:

[0172] Generating total energy feedback information according to the N feedback signals, and generating a first control signal according to the total energy feedback information;

[0173] N second control signals are generated according to any (N-1) feedback signals among the N feedback signals and the collected signal of the secondary power loop.

[0174] In some embodiments, generating total energy feedback information according to N feedback signals specifically includes:

[0175] The signal amplitudes of the N feedback signals are summed up as total energy feedback information.

[0176] For the explanation of the control method of the multi-channel output switching power supply, please refer to the explanation of the multi-channel output switching power supply, which will not be repeated here.

[0177] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0178] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0179] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A multi-output switching power supply, characterized in that: include: Primary power circuit, isolation transformer, secondary power circuit, N output branches and control device; Wherein, the primary power circuit is connected to the primary winding of the isolation transformer; the secondary power circuit is connected to the secondary winding of the isolation transformer, and the secondary power circuit is also connected to N output branches, where N is a natural number greater than 1; The control device is connected to the primary power circuit, the secondary power circuit and the N output branches; The control device is used to adjust the total energy transmitted from the primary winding of the isolation transformer to the secondary winding according to the feedback signals of the N output branches, and control the N output branches to be turned on in time during the freewheeling period of the secondary power circuit.

2. The switching power supply according to claim 1, characterized in that: The isolation transformer comprises a secondary winding, and the input ends of the N output branches are all connected to the first end of the secondary winding; The secondary power circuit includes a second transistor or a diode; Wherein, the first end of the second transistor is connected to the second end of the secondary winding, the second end of the second transistor is grounded, and the control end of the second transistor is connected to the control device; The cathode of the diode is connected to the second end of the secondary winding, and the anode of the diode is grounded.

3. The switching power supply according to claim 1, characterized in that: The isolation transformer comprises N secondary windings, and the N secondary windings correspond to the output branches one by one; the input end of the output branch is connected to the first end of the corresponding secondary winding; The secondary power circuit includes N second transistors or N diodes; the N secondary windings correspond to the N second transistors one by one, and the N secondary windings correspond to the N diodes one by one; A first end of each second transistor is connected to a second end of a corresponding secondary winding, a second end of the second transistor is grounded, and a control end of each second transistor is connected to the control device; The cathode of each diode is connected to the second end of the corresponding secondary winding, and the anode of the diode is grounded.

4. The switching power supply according to any one of claims 1 to 3, characterized in that: The output branch includes an output switch and a capacitor; The first end of the output switch serves as the input end of the output branch, the second end of the output switch is used to connect to the load, the control end of the output switch is connected to the control device, the first plate of the capacitor is connected to the second end of the output switch, and the second plate of the capacitor is grounded.

5. The switching power supply according to any one of claims 1 to 3, characterized in that: The primary power circuit includes a first transistor; The first end of the first transistor is connected to the second end of the primary winding, the second end of the first transistor is grounded, and the control end of the first transistor is connected to the control device.

6. The switching power supply according to any one of claims 1 to 3, characterized in that: The control device includes: a primary controller, an isolation module and a secondary controller; The secondary controller is used to generate total energy feedback information according to N feedback signals, and also to generate N second control signals according to any N-1 feedback signals among the N feedback signals and the collected signal of the secondary power loop; The N second control signals correspond to the N output branches one by one, and each second control signal is used to control the corresponding output branch to be turned on or off; The isolation module is connected to the secondary controller and the primary controller, and is used to transmit the total energy feedback information to the primary controller; the primary controller is used to generate a first control signal according to the total energy feedback information.

7. The switching power supply according to claim 6, characterized in that: The secondary controller includes N operational amplifiers, a channel selection module, and an output switch control module; The first input end of each operational amplifier is connected to the output end of the corresponding output branch, the second input end of each operational amplifier is used to receive the reference output voltage of the output branch, and the output end of each operational amplifier is connected to the channel selection module; The channel selection module is used to select N-1 feedback signals from the N feedback signals for output, and the output switch control module generates a second control signal based on the N-1 feedback signals and the collected signal of the secondary power loop.

8. The switching power supply according to claim 7, characterized in that: The secondary controller includes a total energy control module; The output end of each operational amplifier is connected to the total energy control module; The total energy control module is used to receive the feedback signals output by the N operational amplifiers, and to generate and output the total energy feedback information according to the N feedback signals.

9. The switching power supply according to claim 7, characterized in that: The isolation transformer includes a secondary winding, the switching power supply includes two output branches, and the secondary power circuit is connected to the two output branches via an output bus; Accordingly, the acquisition signal includes the output bus voltage and the drain-source voltage of the second transistor; The output switch control module includes: a signal recognition module, a signal processing module and a logic processing module; The signal recognition module is used to obtain a conduction indication signal of the first transistor according to the output bus voltage and the drain-source voltage of the second transistor; The signal processing module is used to generate a volt-second modulation signal according to the output bus voltage, the drain-source voltage of the second transistor and a preset modulation rule; The logic processing module is connected to the signal identification module, the signal processing module and the channel selection module, and is used to generate two second control signals according to the conduction indication signal, the volt-second modulation signal and the feedback signal output by the channel selection module.

10. The switching power supply according to claim 9, characterized in that: The logic processing module includes: a comparator, an inverter, an AND gate circuit, a first SR trigger and a second SR trigger; The first input end of the comparator is connected to the output end of the channel selection module, and the second input end is connected to the signal processing module; The input end of the inverter is connected to the signal identification module, the output end of the inverter is connected to the first input end of the AND gate circuit, the second input end of the AND gate circuit is connected to the output end of the comparator, the output of the AND gate circuit is connected to the second end of the first SR trigger and the first end of the second SR trigger, the output of the signal identification module is connected to the first end of the first SR trigger and the second end of the second SR trigger, and the output end of the first SR trigger and the output end of the second SR trigger both output a second control signal.

11. A control method for a multi-output switching power supply, characterized in that: The method comprises: According to the feedback signals of the N output branches, the total energy transmitted from the primary winding of the isolation transformer to the secondary winding is adjusted, and the N output branches are controlled to be turned on in time-sharing manner within the freewheeling period of the secondary power circuit.

12. The control method according to claim 11, characterized in that: According to the feedback signals of the N output branches, the total energy transmitted from the primary winding of the isolation transformer to the secondary winding is adjusted, and the N output branches are controlled to be turned on in time-sharing manner during the freewheeling period of the secondary power circuit, specifically including: Generating total energy feedback information according to the N feedback signals, and generating a first control signal according to the total energy feedback information; N second control signals are generated according to any N-1 feedback signals among the N feedback signals and the collected signal of the secondary power loop.

13. The control method according to claim 12, characterized in that: Generating total energy feedback information according to the N feedback signals specifically includes: The signal amplitudes of the N feedback signals are summed up to obtain total energy feedback information.

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