Control method and device of buck-boost converter, computer equipment and storage medium

Abstract

The invention relates to the technical field of buck-boost converters, and discloses a buck-boost converter control method and device, computer equipment and a storage medium, and the method comprises the steps: determining a corresponding instruction parameter according to the difference between an expected value and an actual value of a buck-boost converter; determining a first duty ratio of an input switch tube and a second duty ratio of an output switch tube in the buck-boost converter according to the instruction parameters; along with the change of the instruction parameter, at least one of the first duty ratio and the second duty ratio is adjusted, and in the value range of the instruction parameter, the ratio of the first duty ratio to the second duty ratio continuously changes; the input switch tube is controlled according to the first duty ratio, and the output switch tube is controlled according to the second duty ratio. The duty ratio is calculated under the constraint that the ratio of the first duty ratio of the input switch tube to the second duty ratio of the output switch tube needs to be continuously changed, and smooth mode switching can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of buck-boost converters, and in particular to a control method, device, computer equipment and storage medium for buck-boost converters. Background Art

[0002] At present, there is a demand for energy transfer between batteries in the fields of electric vehicles and the like, which can be achieved based on a buck-boost converter. A buck-boost converter is a bidirectional reversible DC converter, which generally includes three control strategies: boost control, buck control, and buck-boost control.

[0003] However, when switching between the three control strategies, there are jumps in the regulation process due to reasons such as dead zones, making it difficult to achieve smooth switching between the three control strategies. Summary of the invention

[0004] In view of this, the present invention provides a control method, device, computer equipment and storage medium for a buck-boost converter to solve the problem that strategies are difficult to switch smoothly.

[0005] In a first aspect, the present invention provides a control method for a buck-boost converter, comprising:

[0006] Determine a corresponding instruction parameter according to the difference between the expected value and the actual value of the buck-boost converter;

[0007] According to the instruction parameter, a first duty cycle of an input switch tube and a second duty cycle of an output switch tube in the buck-boost converter are determined; as the instruction parameter changes, at least one of the first duty cycle and the second duty cycle is adjusted, and within the value range of the instruction parameter, the ratio between the first duty cycle and the second duty cycle changes continuously;

[0008] The input switch tube is controlled according to the first duty cycle, and the output switch tube is controlled according to the second duty cycle.

[0009] In a second aspect, the present invention provides a control device for a buck-boost converter, comprising:

[0010] A parameter determination module, used for determining corresponding instruction parameters according to the difference between the expected value and the actual value of the buck-boost converter;

[0011] a processing module, configured to determine, according to the instruction parameter, a first duty cycle of an input switch tube and a second duty cycle of an output switch tube in the buck-boost converter; as the instruction parameter changes, at least one of the first duty cycle and the second duty cycle is adjusted, and within a value range of the instruction parameter, a ratio between the first duty cycle and the second duty cycle changes continuously;

[0012] A control module is used to control the input switch tube according to the first duty cycle, and to control the output switch tube according to the second duty cycle.

[0013] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the control method of the buck-boost converter of the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0014] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the control method for a buck-boost converter of the first aspect or any corresponding embodiment thereof.

[0015] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions for causing a computer to execute the control method for a buck-boost converter according to the first aspect or any corresponding embodiment thereof.

[0016] The present invention determines the corresponding instruction parameters according to the difference between the expected value and the actual value of the buck-boost converter, and determines the first duty cycle and the second duty cycle corresponding to the instruction parameters under the constraint that the ratio between the first duty cycle of the input switch tube and the second duty cycle of the output switch tube needs to change continuously; the corresponding switch tubes are controlled based on the first duty cycle and the second duty cycle, so that the ratio of the input voltage to the output voltage can also change continuously, thereby achieving smooth mode switching; and, there is no need to compare the actually collected input voltage and output voltage, which can reduce the problem of control errors caused by sampling errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 is a structural schematic diagram of a buck-boost converter according to an embodiment of the present invention;

[0019] Figure 2 is a flow chart of a control method of a buck-boost converter according to an embodiment of the present invention;

[0020] Figure 3is a logic schematic diagram of calculating a duty cycle based on instruction parameters according to an embodiment of the present invention;

[0021] Figure 4 is another logic schematic diagram for calculating a duty cycle based on instruction parameters according to an embodiment of the present invention;

[0022] Figure 5 is a flow chart of another method for controlling a buck-boost converter according to an embodiment of the present invention;

[0023] Figure 6 is a schematic diagram of a piecewise function relationship according to an embodiment of the present invention;

[0024] Figure 7 is a schematic diagram of a first functional relationship and a second functional relationship according to an embodiment of the present invention;

[0025] Figure 8 is a schematic diagram of a process for determining a duty cycle according to an embodiment of the present invention;

[0026] Fig. 9 is another schematic diagram of a first functional relationship and a second functional relationship according to an embodiment of the present invention;

[0027] Fig.10 is another schematic diagram of a process for determining a duty cycle according to an embodiment of the present invention;

[0028] Fig.11 is another schematic diagram of the first functional relationship and the second functional relationship according to an embodiment of the present invention;

[0029] Fig.12 is another schematic diagram of a process for determining a duty cycle according to an embodiment of the present invention;

[0030] Fig.13 is a structural block diagram of a control device for a buck-boost converter according to an embodiment of the present invention;

[0031] Fig.14 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0033] One structure of a buck-boost converter can be found in Figure 1 As shown in the figure. To achieve closed-loop control under any input voltage Vi and output voltage Vo, existing solutions generally use three control strategies. That is, when Vo > Vi, Boost control (step-up control) is used with Q1 closed, Q2 open, and Q3 and Q4 conducting alternately. When Vo < Vi, Buck control (step-down control) is used with Q3 closed, Q4 open, and Q1 and Q2 conducting alternately. And when Vo ≈ Vi, Buck-Boost control (step-up / step-down control) is used with Q1 and Q2 conducting alternately and Q3 and Q4 conducting alternately.

[0034] For Figure 1 the step-up / step-down converter shown in the figure, currently, the mode switching is generally performed by comparing the magnitude relationship between the input voltage Vi and the output voltage Vo. However, there are sampling errors in the input voltage Vi and the output voltage Vo, which easily lead to the selection of the wrong control strategy.

[0035] Some solutions will perform mode switching based on the deviation between the actual value and the reference value of the voltage, which can reduce the influence of sampling errors to a certain extent. However, in order to perform smooth mode switching, some solutions need to use additional transition modes, etc. for mode switching, but the overall control strategy of this method is too complex, and it will also increase the number of modes of the step-up / step-down converter, which is more unfavorable for smooth switching.

[0036] The control method of the step-up / step-down converter provided by the embodiments of the present invention takes the duty cycle ratio between the input switching tube on the input side and the output switching tube on the output side as a constraint, and determines the duty cycles of the input switching tube and the output switching tube according to the current actual situation of the step-up / step-down converter while constraining the continuous change of the duty cycle ratio. In this way, voltage mutation can be effectively avoided while switching modes, so as to achieve smooth switching.

[0037] According to the embodiments of the present invention, an embodiment of a control method for a step-up / step-down converter is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0038] In this embodiment, a control method for a step-up / step-down converter is provided, which can be applied to a control device of a step-up / step-down converter, such as a control chip, etc. Figure 2 is a flowchart of the control method for a step-up / step-down converter according to the embodiments of the present invention. As Figure 2 shown, the process includes the following steps.

[0039] Step S201, determine the corresponding instruction parameters according to the difference between the expected value and the actual value of the step-up / step-down converter.

[0040] In this embodiment, when controlling the buck-boost converter, it is necessary to set an expected value of a physical parameter of the buck-boost converter; and, the actual value of the physical parameter can be collected in real time based on sensors, etc., and the difference between the expected value and the actual value can be determined by comparing the expected value and the actual value, thereby generating a parameter for indicating how to control the buck-boost converter, i.e., an instruction parameter.

[0041] The physical parameter may be, for example, an inductor current, an output voltage, etc. of a buck-boost converter, which may be determined based on actual needs.

[0042] The command parameter corresponding to the difference between the expected value and the actual value may be determined based on a feedback controller, etc. For example, the feedback controller may be a PI (Proportional Integral) controller, or other controllers may be used, which are not limited in this embodiment.

[0043] Step S202, determining a first duty cycle of an input switch tube and a second duty cycle of an output switch tube in a buck-boost converter according to instruction parameters; as the instruction parameters change, at least one of the first duty cycle and the second duty cycle will be adjusted, and within the value range of the instruction parameters, the ratio between the first duty cycle and the second duty cycle changes continuously.

[0044] like Figure 1 The buck-boost converter shown in the figure provides an input voltage Vi on the input side, and can convert the input voltage Vi into a desired output voltage Vo by controlling the on and off of the switch tube therein. The input side of the buck-boost converter is provided with two switch tubes, namely Q1 and Q2. In this embodiment, the two switch tubes are both referred to as input switch tubes, that is, the input switch tube can be Q1 or Q2; similarly, the output side of the buck-boost converter is also provided with two switch tubes, namely Q3 and Q4. In this embodiment, the two switch tubes are both referred to as output switch tubes, that is, the output switch tube can be Q3 or Q4.

[0045] And, if Figure 1 As shown, the switch tube Q2 and the switch tube Q4 have a common pole, for example, a common source, and the common pole can be grounded. For the convenience of distinguishing descriptions, the input switch tube (i.e., Q1) that is not in common with the switch tube (Q3 or Q4) on the output side is called the first input switch tube, and the input switch tube (i.e., Q2) that is in common with a certain switch tube (Q4) on the output side is called the second input switch tube. Similarly, the output switch tube (i.e., Q3) that is not in common with the switch tube (Q1 or Q2) on the input side is called the first output switch tube, and the output switch tube (i.e., Q4) that is in common with a certain switch tube (Q2) on the input side is called the second output switch tube.

[0046] For the first input switch tube Q1 and the second input switch tube Q2, the duty ratios of the two are complementary, that is, when the first input switch tube Q1 is turned on, the second input switch tube Q2 is turned off, and when the first input switch tube Q1 is turned off, the second input switch tube Q2 is turned on, and the sum of the two duty ratios is 1; therefore, when controlling the two switch tubes on the input side, it is only necessary to determine the duty ratio of one of the switch tubes. Similarly, for the first output switch tube Q3 and the second output switch tube Q4, the duty ratios of the two are also complementary, so it is also possible to determine the duty ratio of only one of the switch tubes.

[0047] In this embodiment, the duty cycle of the input switch tube that needs to be determined is referred to as the first duty cycle, and the duty cycle of the output switch tube that needs to be determined is referred to as the second duty cycle. It can be understood that the first duty cycle can be the duty cycle of the first input switch tube Q1, or the duty cycle of the second input switch tube Q2; similarly, the second duty cycle can be the duty cycle of the first output switch tube Q3, or the duty cycle of the second output switch tube Q4. For the sake of simplicity of description, the duty cycle of the first input switch tube Q1 is mainly referred to as the first duty cycle, and the duty cycle of the first output switch tube Q3 is referred to as the second duty cycle.

[0048] In order to ensure smooth mode switching of the buck-boost converter, it is necessary to make the input voltage Vi or the output voltage Vo of the buck-boost converter change smoothly. Regardless of whether the buck-boost converter is in the boost control mode, the buck control mode or the buck-boost control mode, the ratio of its output voltage Vo to the input voltage Vi can be expressed by the ratio between the first duty cycle of the input switch tube and the second duty cycle of the output switch tube.

[0049] For example, with Di cmd Indicates the first duty cycle of the input switch tube, with Do cmd Represents the second duty cycle of the output switch tube. If the input switch tube is the first input switch tube Q1, and the output switch tube is the first output switch tube Q3, then Vo / Vi=Di cmd / Do cmd .

[0050] Specifically, the determined instruction parameter has a certain value range, within which the first duty cycle Di is constrained. cmd With the second duty cycle Do cmd The ratio between them changes continuously. Under this constraint, the first duty cycle Di cmd With the second duty cycle Do cmd , which can ensure that the input voltage Vi and / or the output voltage Vo of the buck-boost converter changes continuously.

[0051] Moreover, as the difference between the expected value and the actual value of the buck-boost converter changes, the determined instruction parameter will also change; in order to adapt to the actual situation of the buck-boost converter, at least the first duty cycle Di cmd With the second duty cycle Do cmd Of course, the first duty cycle Di can also be adjusted at the same time cmd and the second duty cycle Do cmd , which is based on the actual control strategy.

[0052] Step S203, controlling the input switch tube according to the first duty cycle, and controlling the output switch tube according to the second duty cycle.

[0053] In this embodiment, when determining the first duty cycle Di of the input switch tube cmd And the second duty cycle Do of the output switch tube cmd Afterwards, the corresponding switch tubes can be controlled based on the two duty ratios. cmd Generate a first PWM control signal for controlling the input switch tube, and control the on-off control of the input switch tube by controlling the level of the gate of the input switch tube. cmd Generate a second PWM control signal for controlling the output switch tube, so that the output switch tube can be controlled according to the second duty cycle Do cmd Control the corresponding output switch tube.

[0054] For example, Figure 3 As shown, the corresponding command parameter Cmd can be determined based on the inductor current of the buck-boost converter, and the first duty cycle Di can be calculated. cmd and the second duty cycle Do cmd Among them, IL is the actual value of the inductor current, IL cmd is the expected value of the inductor current; PI represents the PI controller.

[0055] Or, if Figure 4 As shown, the corresponding command parameter Cmd can also be determined based on the output voltage of the buck-boost converter, and the first duty cycle Di can be calculated. cmd and the second duty cycle Do cmd Among them, Vo is the actual value of the output voltage, Vo cmd is the expected value of the output voltage.

[0056] Furthermore, the method provided in this embodiment may be applied to single-loop control; or, may also be applied to dual-loop control, for example, to the current inner loop in the voltage dual-loop control, which is not limited here.

[0057] It can be understood that based on the above method, the duty cycle Di of a switch tube (such as Q1) on the input side is determined. cmd And the duty cycle Do of a switch tube (such as Q3) on the output side cmd After that, it can be further determined that the duty cycle of another switch tube (such as Q2) on the input side is 1-Di cmd , the duty cycle of the other switch tube (such as Q4) on the output side is 1-Do cmd .

[0058] The control method of the buck-boost converter provided in the present embodiment determines the corresponding instruction parameters according to the difference between the expected value and the actual value of the buck-boost converter, and determines the first duty cycle and the second duty cycle corresponding to the instruction parameters under the constraint that the ratio between the first duty cycle of the input switch tube and the second duty cycle of the output switch tube needs to change continuously; the corresponding switch tubes are controlled based on the first duty cycle and the second duty cycle, so that the ratio of the input voltage to the output voltage can also change continuously, thereby achieving smooth mode switching; and, there is no need to compare the actually collected input voltage and output voltage, which can reduce the problem of control errors caused by sampling errors.

[0059] In this embodiment, a control method for a buck-boost converter is provided, which can be applied to a control device of the buck-boost converter, such as a control chip. Figure 5 is a flow chart of a control method of a buck-boost converter according to an embodiment of the present invention. Figure 5 As shown, the process includes the following steps.

[0060] Step S501, determining a corresponding instruction parameter according to a difference between an expected value and an actual value of the buck-boost converter.

[0061] For details, please see Figure 2 Step S201 of the illustrated embodiment will not be described in detail here.

[0062] Step S502, determining a first duty cycle of an input switch tube and a second duty cycle of an output switch tube in a buck-boost converter according to instruction parameters; as the instruction parameters change, at least one of the first duty cycle and the second duty cycle will be adjusted, and within the value range of the instruction parameters, the ratio between the first duty cycle and the second duty cycle changes continuously.

[0063] Specifically, the above step S502 "determines the first duty cycle of the input switch tube and the second duty cycle of the output switch tube in the buck-boost converter according to the instruction parameters" includes the following steps S5021 to S5022.

[0064] Step S5021, determining a first duty cycle corresponding to the instruction parameter according to a preset first functional relationship; the first functional relationship is a functional relationship between the instruction parameter and the duty cycle of the input switch tube.

[0065] Step S5022, determining a second duty cycle corresponding to the instruction parameter according to a preset second functional relationship; the second functional relationship is a functional relationship between the instruction parameter and the duty cycle of the output switch tube.

[0066] In this embodiment, in order to facilitate the determination of the first duty cycle and the second duty cycle, a functional relationship related to the instruction parameter is set in advance for the duty cycle of the input switch tube, that is, the first functional relationship f; wherein, if the currently determined instruction parameter is Cmd, then based on the first functional relationship f, it can be determined that the first duty cycle Dicmd of the input switch tube is: Di cmd =f(Cmd).

[0067] Similarly, a functional relationship related to the instruction parameter can be set in advance for the duty cycle of the output switch tube, that is, the second functional relationship g; wherein, if the currently determined instruction parameter is Cmd, then based on the second functional relationship g, it can be determined that the second duty cycle Docmd of the output switch tube is: Do cmd =g(Cmd).

[0068] In some optional implementations, the value range of the instruction parameter is divided into a voltage reduction range, a voltage increase / decrease range, and a voltage increase range by a first threshold value th1 and a second threshold value th2.

[0069] Specifically, Figure 6 As shown, the value range of the instruction parameter Cmd corresponds to the first limit a and the second limit b; the range between the first limit a and the first threshold th1 is the voltage reduction range, the range between the first threshold th1 and the second threshold th2 is the voltage increase / decrease range, and the range between the second threshold th2 and the second limit b is the voltage increase range.

[0070] It should be noted that the magnitude relationship between the first limit value a and the second limit value b is specifically determined based on the generation method of the instruction parameter Cmd; for example, if the instruction parameter corresponding to the buck mode is smaller than the instruction parameter corresponding to the boost mode, then Figure 6 As shown, a is smaller than b; on the contrary, a is larger than b. Similarly, the magnitude relationship between the first threshold th1 and the second threshold th2 is also related to this, which will not be described in detail.

[0071] In this embodiment, for different value ranges of the command parameter Cmd, suitable functions may be set for the first duty cycle and the second duty cycle, that is, the first functional relationship and the second functional relationship may both include multiple-segment functional relationships.

[0072] Specifically, Figure 6As shown, the first functional relationship includes a first voltage reduction function f corresponding to the voltage reduction range. Buck , the first step-up / step-down function f corresponding to the step-up / step-down range Buck-Boost The first boost function f corresponding to the boost range Boost Similarly, the second functional relationship includes a second pressure reduction function g corresponding to the pressure reduction range Buck , the second step-up / step-down function g corresponding to the step-up / step-down range Buck-Boost The second boost function g corresponding to the boost range Boost .

[0073] Among them, in order to ensure the first duty cycle Di cmd With the second duty cycle Do cmd The ratio G (i.e. G = Di cmd / Do cmd ) is continuously changing. In each value range (including the step-down range, the step-up / step-down range, and the step-up range), each function can be a continuously changing function, that is, the function is a continuous non-constant function. For example, the first step-down function f Buck , the second step-down function g Buck etc. are all continuously changing functions.

[0074] Furthermore, in order to ensure that the ratio G is still continuous when the instruction parameter Cmd changes at the first threshold value th1 and the second threshold value th2, in this embodiment, the above function is set to satisfy the following relationship:

[0075]

[0076] Where th1 represents the first threshold value, and th2 represents the second threshold value. It can be understood that f Buck (th1) indicates that when Cmd is the first threshold th1, based on the first voltage reduction function f Buck The determined first duty cycle Di cmd Similarly, g Buck (th1) indicates that when Cmd is the first threshold th1, based on the second step-down function g B The second duty cycle Docmd determined by uck. Buck-Boost (th1), g Buck-Boost (th1) is when Cmd is the first threshold th1, based on the first step-up and step-down function f Buck-Boost , the second step-up / step-down function g Buck-Boost The determined first duty cycle Di cmd , the second duty cycle Do cmd The meanings of the remaining parameters are similar and will not be described here.

[0077] In this embodiment, by dividing the value range of the command parameter Cmd into a step-down range, a step-up / step-down range, and a step-up range, suitable functions can be set for different ranges to respectively determine the first duty cycle and the second duty cycle, thereby meeting various control requirements. Moreover, based on the range that the command parameter Cmd falls into, the first duty cycle and the second duty cycle can be directly calculated based on the corresponding function, and the calculation method is simple.

[0078] Optionally, since the switch tube is generally provided with a dead zone (the switch tubes of the upper and lower half bridges are both turned off), and the dead zone causes a jump in the regulation process, which makes the overall control strategy of the buck-boost converter too complicated. In this embodiment, a dead zone coefficient is set for the buck-boost range separated by the instruction parameter to simplify the control strategy.

[0079] Specifically, the method further includes: presetting a dead zone coefficient Ddt. The dead zone coefficient Ddt is used to limit the maximum value of the duty cycle, and the dead zone coefficient Ddt is a value between 0 and 1; generally, the dead zone coefficient Ddt is greater than 0.5; for example, the dead zone coefficient Ddt is 0.7, 0.8, etc., which is specifically set based on actual needs.

[0080] Among them, when the instruction parameter is within the step-up / step-down range, the first duty cycle Di cmd and the second duty cycle Do cmd The dead zone coefficient Ddt does not exceed the dead zone coefficient Ddt. That is, based on the first boost / lower pressure function f Buck-Boost , the second step-up / step-down function g Buck-Boost The determined duty cycle does not exceed the dead zone coefficient Ddt.

[0081] In this embodiment, by setting the dead zone coefficient, the first duty cycle Di is limited when the command parameter Cmd is within the step-up / step-down range. cmd and the second duty cycle Do cmd The size of the dead zone control can be realized, and based on the first step-up and step-down function f Buck-Boost , the second step-up / step-down function g Buck-Boost The appropriate duty cycle can be directly calculated and the control method is simple.

[0082] Optionally, the first boost function f Boost is a constant function; if the input switch tube is the first input switch tube Q1 which is not in common with the output side, that is, the first duty cycle is the duty cycle of the first input switch tube Q1, then according to the first boost function f Boost The determined first duty cycle is the preset maximum duty cycle; if the input switch tube is the second input switch tube Q2 with a common electrode with the output side, that is, the first duty cycle is the duty cycle of the second input switch tube Q2, then according to the first boost function f Boost The determined first duty cycle is a preset minimum duty cycle.

[0083] Similarly, the second step-down function g Buck is a constant function; if the output switch tube is the first output switch tube Q3 which is not in common with the input side, that is, the second duty cycle is the duty cycle of the first output switch tube Q3, then according to the second step-down function g Buck The determined second duty cycle is the preset maximum duty cycle; if the output switch tube is the second output switch tube Q4 with the input side in common, that is, the second duty cycle is the duty cycle of the second output switch tube Q4, then according to the second step-down function g Buck The determined second duty cycle is a preset minimum duty cycle.

[0084] For example, the maximum duty cycle is 1 and the minimum duty cycle is 0, which can reduce the switching loss in the boost range or the buck range. Taking the first duty cycle as the duty cycle of the first input switch tube Q1 as an example, when the command parameter Cmd is in the boost range, f Boost (Cmd) = 1. Taking the second duty cycle as the duty cycle of the second input switch tube Q3 as an example, when the instruction parameter Cmd is within the step-up / step-down range, g Buck (Cmd)=1.

[0085] In this embodiment, the first boost function f Boost and the second step-down function g Buck If it is set as a constant function, when the instruction parameter Cmd falls within the corresponding range, as the instruction parameter Cmd changes, one of the first duty cycle or the second duty cycle will not change, thereby simplifying the control of the corresponding switch tube and avoiding frequent adjustment of the duty cycle of the switch tube.

[0086] Optionally, as described above, the value range of the command parameter Cmd corresponds to the first limit a and the second limit b. The range between the first limit a and the first threshold th1 is the voltage reduction range, the range between the first threshold th1 and the second threshold th2 is the voltage increase / decrease range, and the range between the second threshold th2 and the second limit b is the voltage increase range.

[0087] In the second step-down function g Buck When it is a constant function, the first step-down function f Buck is a continuously changing function; and, within the range from the first limit value th1 to the first threshold value a, that is, when the instruction parameter Cmd changes from the first limit value th1 to the first threshold value a, if the input switch tube is the first input switch tube Q1 that is not in common with the output side, then the first step-down function f Buck is a monotonically increasing function; if the input switch tube is the second input switch tube Q2 with the same pole as the output side, then the first step-down function f Buck is a monotonically decreasing function.

[0088] For example, the first step-down function f BuckIt can be a linear function. For example, it can be preset that when Cmd=th1, the first duty cycle Di cmd It needs to be set to D1, then the first step-down function f Buck It can be expressed as:

[0089] Among them, when Cmd = a, f Buck (Cmd)=0,Cmd=th1,f Buck (Cmd) = D1.

[0090] Similarly, in the first boost function f Boost When the second boost function g is a constant function, Boost is a continuously changing function; and, within the range corresponding to the second threshold value th2 to the second limit value b, that is, when the instruction parameter Cmd changes from the second threshold value th2 to the second limit value b, if the output switch tube is the first output switch tube Q3 which is not in common with the input side, then the second boost function g Boost is a monotonically decreasing function; if the output switch tube is the second output switch tube Q4 with the same electrode as the input side, then the second boost function g Boost is a monotonically increasing function.

[0091] For example, the second boost function g Boost It can be a linear function. For example, it can be preset that when Cmd=th2, the first duty cycle Di cmd Need to be set to D2, then the second boost function g Boost It can be expressed as:

[0092] Among them, when Cmd = b, g Boost (Cmd) = 0, Cmd = th2, g Boost (Cmd) = D2, wherein D1 and D2 may be the same.

[0093] For example, the first limit value a of the instruction parameter Cmd is 0, the second limit value b is 2, the first threshold value th1 is Dsw, and the second threshold value th2 is 2-Dsw. For example, the first duty cycle is the duty cycle of the first input switch tube Q1, and the second duty cycle is the duty cycle of the first output switch tube Q3. Figure 7 A schematic diagram showing the first functional relationship and the second functional relationship is shown, wherein the solid line represents the function for determining the first duty cycle Di cmd The dotted line represents the first functional relationship for determining the second duty cycle Do cmd Furthermore, when the instruction parameter Cmd is within the step-up / step-down range, the first step-up / step-down function f Buck-Boost and the second buck-boost function g Buck-Boost can all be continuously changing functions, Figure 7This is illustrated by taking two functions as linear functions.

[0094] Taking Figure 7 the functions shown as an example, the first function relationship and the second function relationship can be expressed as:

[0095] The first buck function f Buck (Cmd) = cmd;

[0096] The first buck-boost function f Buck-Boost (Cmd) = (Dsw + Cmd) * Ddt2;

[0097] The first boost function f Boost (Cmd) = 1.

[0098] The second buck function g Buck (Cmd) = 1;

[0099] The second buck-boost function g Buck-Boost (Cmd) = (Dsw - Cmd) * Ddt2 + Ddt;

[0100] The second boost function g Boost (Cmd) = 2 - Cmd.

[0101] Figure 8 A flow schematic diagram for determining the duty cycle is shown. As Figure 8 shown, if the instruction parameter Cmd is within the buck range, i.e., Cmd < Dsw, then based on the above first buck function f Buck and the second buck function g Buck it can be determined that: Di cmd = Cmd, Do cmd = 1.

[0102] If the instruction parameter Cmd is within the buck-boost range, i.e., Dsw < Cmd < (2 - Dsw), then based on the above first buck-boost function f Buck-Boost and the second buck-boost function g Buck-Boost it can be determined that: Di cmd = (Dsw + Cmd) * Ddt / 2, Do cmd = (Dsw - Cmd) * Ddt / 2 + Ddt.

[0103] If the instruction parameter Cmd is within the boost range, i.e., Cmd > (2 - Dsw), then based on the above first boost function f Boost and the second boost function g Boost it can be determined that: Di cmd = 1, Do cmd = 2 - Cmd.

[0104] In this case, when the command parameter Cmd is between 0 and Dsw, the ratio of the two duty cycles G = Cmd. When the command parameter Cmd is between Dsw and (2-Dsw), G = (Dsw + Cmd) / (Dsw-Cmd + 2). When the command parameter Cmd is between (2-Dsw) and 2, G = 1 / (2-Cmd). It can be determined that the ratio G changes continuously.

[0105] In some optional implementations, in order to avoid adjusting the duty cycle of the switch tube too frequently, the buck-boost range is further divided. Specifically, the buck-boost range is divided by the third threshold th3 into a first sub-range between the first threshold th1 and the third threshold th3, and a second sub-range between the third threshold th3 and the second threshold th2.

[0106] In the first sub-range, the first buck-boost function f Buck-Boost is a continuously changing function, and the second step-up and step-down function g Buck-Boost is a constant function that does not exceed the dead zone coefficient; in the second sub-range, the first step-up and step-down function f Buck-Boost is a constant function that does not exceed the dead zone coefficient, and the second step-up and step-down function g Buck-Boost is a continuously changing function.

[0107] Alternatively, in the first sub-range, the first buck-boost function f Buck-Boost is a constant function that does not exceed the dead zone coefficient, and the second step-up and step-down function g Buck-Boost is a continuously changing function; in the second sub-range, the first step-up and step-down function f Buck-Boost is a continuously changing function, and the second step-up and step-down function g Buck-Boost is a constant function that does not exceed the dead zone coefficient.

[0108] As described above, within the first sub-range or the second sub-range, one of the first functional relationship and the second functional relationship is a constant function, that is, the duty cycle of a certain switching tube is fixed, thereby reducing the adjustment of the duty cycle; and, one of the first functional relationship and the second functional relationship is a continuously changing function, so that the ratio G between the first duty cycle and the second duty cycle changes with the command parameter Cmd, thereby realizing on-demand adjustment of the buck-boost converter.

[0109] Further optionally, if the first step-up / step-down function f Buck-Boost is a continuously changing function. For example, in the first sub-range, the first step-up / step-down function f Buck-Boost is a continuously changing function, or, in the second sub-range, the first step-up / step-down function f Buck-Boostis a continuously changing function; in this case, within the range corresponding to the first threshold value th1 to the third threshold value th3 (i.e., the command parameter Cmd changes from the first threshold value th1 to the third threshold value th3), or within the range corresponding to the third threshold value th3 to the second threshold value th2 (i.e., the command parameter Cmd changes from the third threshold value th3 to the second threshold value th2), if the input switch tube is the first input switch tube Q1 that is not in common with the output side, the first buck-boost function f Buck-Boost is a monotonically increasing function; if the input switch tube is the second input switch tube Q2 with the same electrode as the output side, the first step-up and step-down function f Buck-Boost is a monotonically decreasing function.

[0110] Similarly, in the second step-up / step-down function g Buck-Boost In the case of a continuously changing function, for example, in the first sub-range, the second step-up / step-down function g Buck-Boost is a continuously changing function, or, in the second sub-range, the second step-up / step-down function g Buck-Boost is a continuously changing function; in this case, within the range corresponding to the first threshold value th1 to the third threshold value th3 (i.e., the command parameter Cmd changes from the first threshold value th1 to the third threshold value th3), or within the range corresponding to the third threshold value th3 to the second threshold value th2 (i.e., the command parameter Cmd changes from the third threshold value th3 to the second threshold value th2), if the output switch tube is the first output switch tube Q3 that is not in common with the input side, the second buck-boost function g Buck-Boost is a monotonically decreasing function; if the output switch tube is the second output switch tube Q4 with the same electrode as the input side, the second buck-boost function g Buck-Boost is a monotonically increasing function.

[0111] In this embodiment, within the first sub-range or the second sub-range, if the first step-up / step-down function f Buck-Boost and the second buck-boost function g Buck-Boost If one of them is a constant function, the other is a continuously changing function and a monotonic function. Taking the input switch tube as the first input switch tube Q1 as an example, Figure 6 As shown in FIG. 1 , when the instruction parameter Cmd changes from the step-down range to the step-up range, the first functional relationship shows an increasing trend as a whole; and taking the output switch tube as the second input switch tube Q3 as an example, as shown in FIG. Figure 6 As shown, when the command parameter Cmd changes from the voltage reduction range to the voltage increase range, the second functional relationship shows a decreasing trend as a whole. Based on this, it can be determined that within the first sub-range or the second sub-range, the first voltage reduction and voltage increase function f Buck-Boost and the second buck-boost function g Buck-Boost is a monotonically increasing function or a monotonically decreasing function.

[0112] For example, the first limit value a of the instruction parameter Cmd is 0, the second limit value b is 2, the first threshold th1 is Dsw, the second threshold th2 is 2 - Dsw; the third threshold th3 is 1. Taking the first duty cycle as the duty cycle of the first input switching transistor Q1 and the second duty cycle as the duty cycle of the first output switching transistor Q3 as an example, Fig. 9 Another schematic diagram showing the first functional relationship and the second functional relationship is presented. The solid line represents the first functional relationship used to determine the first duty cycle Di cmd and the dashed line represents the second functional relationship used to determine the second duty cycle Do cmd . Among them, the first functional relationship and the second functional relationship within the buck range or the boost range are the same as those Figure 7 shown, and will not be elaborated here.

[0113] As Fig. 9 shown, within the first sub - range, that is, when Dsw < Cmd < 1, the first buck - boost function f Buck-Boost is a monotonically increasing function, and the second buck - boost function g Buck-Boost is a constant function, and:

[0114] f Buck-Boost (Cmd) = Cmd * Ddt; g Buck-Boost (Cmd) = Ddt.

[0115] Within the second sub - range, that is, when 1 < Cmd < 2 - Dsw, the first buck - boost function f Buck-Boost is a constant function, and the second buck - boost function g Buck-Boost is a monotonically decreasing function, and:

[0116] f Buck-Boost (Cmd) = Ddt; g Buck-Boost (Cmd) = (2 - Cmd) * Ddt.

[0117] Fig.10 A schematic diagram of a process for determining the duty cycle is presented. As Fig.10 shown, if the instruction parameter Cmd is within the buck range, that is, Cmd < Dsw, then based on the above - mentioned first buck function f Buck and the second buck function g Buck it can be determined that: Di cmd = Cmd, Do cmd = 1.

[0118] If the instruction parameter Cmd is within the buck - boost range, that is, Dsw < Cmd < (2 - Dsw), when the instruction parameter Cmd is within the first sub - range (i.e., Cmd < 1), then based on the above - mentioned first buck - boost function f Buck-Boost and the second buck - boost function g Buck-Boost it can be determined that: Dicmd = Cmd * Ddt, Do cmd = Ddt. When the instruction parameter Cmd is within the second sub - range (i.e., Cmd > 1), Di cmd = Ddt, Do cmd = (2 - Cmd) * Ddt.

[0119] If the instruction parameter Cmd is within the boost range, i.e., Cmd > (2 - Dsw), then based on the above - mentioned first boost function f Boost and the second boost function g Boost it can be determined that: Di cmd = 1, Do cmd = 2 - Cmd.

[0120] In this case, when the instruction parameter Cmd is between 0 and Dsw, the ratio G of the two duty cycles = Cmd. When the instruction parameter Cmd is between Dsw and 1, G = Cmd; when the instruction parameter Cmd is between 1 and (2 - Dsw), G = 1 / (2 - Cmd). When the instruction parameter Cmd is between (2 - Dsw) and 2, G = 1 / (2 - Cmd). It can be determined that this ratio G also changes continuously.

[0121] Similarly, still taking the first duty cycle as the duty cycle of the first input switch Q1 and the second duty cycle as the duty cycle of the first output switch Q3 as an example, Fig.11 shows another schematic diagram of the first functional relationship and the second functional relationship. Its solid line represents the first functional relationship for determining the first duty cycle Di cmd and the dashed line represents the second functional relationship for determining the second duty cycle Do cmd Among them, the first functional relationship and the second functional relationship within the buck range or the boost range are the same as those Figure 7 shown, and will not be elaborated here.

[0122] As Fig.11 shown, within the first sub - range, i.e., when Dsw < Cmd < 1, the first buck - boost function f Buck-Boost is a constant function, and the second buck - boost function g Buck-Boost is a monotonically decreasing function, and:

[0123] f Buck-Boost (Cmd) = Dsw * Ddt; g Buck-Boost (Cmd) = (Dsw + 1 - Cmd) * Ddt.

[0124] Within the second sub - range, i.e., when 1 < Cmd < 2 - Dsw, the first buck - boost function f Buck-Boost is a monotonically increasing function, and the second buck - boost function g Buck-Boost is a constant function, and:

[0125] f Buck-Boost (Cmd) = (Dsw - 1 + Cmd) * Ddt; g Buck-Boost (Cmd) = Dsw * Ddt.

[0126] Fig.12 Shows a schematic flow chart for determining the duty cycle. As Fig.12 shown, if the command parameter Cmd is within the buck range, i.e., Cmd < Dsw, then based on the above first buck function f Buck and the second buck function g Buck it is possible to determine: Di cmd = Cmd, Do cmd = 1.

[0127] If the command parameter Cmd is within the buck-boost range, i.e., Dsw < Cmd < (2 - Dsw), when the command parameter Cmd is within the first sub-range (i.e., Cmd < 1), then based on the above first buck-boost function f Buck-Boost and the second buck-boost function g Buck-Boost it is possible to determine: Di cmd = Dsw * Ddt, Do cmd = (Dsw + 1 - Cmd) * Ddt. When the command parameter Cmd is within the second sub-range (i.e., Cmd > 1), Di cmd = (Dsw - 1 + Cmd) * Ddt, Do cmd = Dsw * Ddt.

[0128] If the command parameter Cmd is within the boost range, i.e., Cmd > (2 - Dsw), then based on the above first boost function f Boost and the second boost function g Boost it is possible to determine: Di cmd = 1, Do cmd = 2 - Cmd.

[0129] In this case, when the command parameter Cmd is between 0 and Dsw, the ratio G of the two duty cycles = Cmd. When the command parameter Cmd is between Dsw and 1, G = Dsw / (Dsw + 1 - Cmd); when the command parameter Cmd is between 1 and (2 - Dsw), G = (Dsw - 1 + Cmd) / Dsw. When the command parameter Cmd is between (2 - Dsw) and 2, G = 1 / (2 - Cmd). It can be determined that this ratio G also changes continuously.

[0130] Step S503, control the input switch tube according to the first duty cycle and control the output switch tube according to the second duty cycle.

[0131] For details, please refer to Figure 2Step S203 of the illustrated embodiment will not be described in detail here.

[0132] The control method of the buck-boost converter provided in this embodiment determines the first duty cycle and the second duty cycle corresponding to the instruction parameter under the constraint that the ratio between the first duty cycle of the input switch tube and the second duty cycle of the output switch tube needs to change continuously, so as to achieve smooth mode switching; and, there is no need to compare the input voltage and output voltage actually collected, so as to reduce the problem of control error caused by sampling error. The value range of the instruction parameter is divided into a buck range, a buck-boost range and a boost range, and appropriate functional relationships can be set in different ranges to meet various control requirements; the functional relationship in a part of the range is set as a constant function, so as to reduce the adjustment of the duty cycle of the switch tube; in addition, the dead zone coefficient is set for the buck-boost range separated by the instruction parameter, so as to simplify the control strategy while achieving dead zone control.

[0133] In this embodiment, a control device for a buck-boost converter is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made will not be repeated. As used below, the term "module" may be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0134] This embodiment provides a control device for a buck-boost converter, such as Fig.13 As shown, including:

[0135] A parameter determination module 1301, for determining corresponding instruction parameters according to a difference between an expected value and an actual value of the buck-boost converter;

[0136] The processing module 1302 is used to determine a first duty cycle of an input switch tube and a second duty cycle of an output switch tube in the buck-boost converter according to the instruction parameter; as the instruction parameter changes, at least one of the first duty cycle and the second duty cycle is adjusted, and within the value range of the instruction parameter, the ratio between the first duty cycle and the second duty cycle changes continuously;

[0137] The control module 1303 is used to control the input switch tube according to the first duty cycle, and control the output switch tube according to the second duty cycle.

[0138] In some optional implementations, the processing module 1302 determines the first duty cycle of the input switch tube and the second duty cycle of the output switch tube in the buck-boost converter according to the instruction parameter, including:

[0139] Determine a first duty cycle corresponding to the instruction parameter according to a preset first functional relationship; the first functional relationship is a functional relationship between the instruction parameter and the duty cycle of the input switch tube;

[0140] Determine a second duty cycle corresponding to the instruction parameter according to a preset second functional relationship; the second functional relationship is a functional relationship between the instruction parameter and the duty cycle of the output switch tube;

[0141] In some optional embodiments, the value range of the instruction parameter is divided into a step-down range, a step-up / step-down range, and a step-up range by the first threshold and the second threshold;

[0142] The first functional relationship includes a first voltage reduction function f corresponding to the voltage reduction range. Buck , the first step-up / step-down function f corresponding to the step-up / step-down range Buck-Boost The first boost function f corresponding to the boost range Boost ;

[0143] The second functional relationship includes a second pressure reduction function g corresponding to the pressure reduction range. Buck , the second step-up / step-down function g corresponding to the step-up / step-down range Buck-Boost The second boost function g corresponding to the boost range Boost ;

[0144] and,

[0145] Herein, th1 represents the first threshold, and th2 represents the second threshold.

[0146] In some optional implementations, the processing module 1302 further includes: presetting a dead zone coefficient; the dead zone coefficient is a value between 0 and 1;

[0147] When the instruction parameter is within the buck-boost range, the determined first duty cycle and the determined second duty cycle do not exceed the dead zone coefficient.

[0148] In some optional embodiments, the buck-boost range is divided by a third threshold into a first sub-range between the first threshold and the third threshold, and a second sub-range between the third threshold and the second threshold;

[0149] In the first sub-range, the first step-up / step-down function f Buck-Boost is a continuously changing function, the second step-up / step-down function g Buck-Boost is a constant function that does not exceed the dead zone coefficient; within the second sub-range, the first step-up and step-down function f Buck-Boost is a constant function that does not exceed the dead zone coefficient, and the second step-up and step-down function gBuck-Boost is a continuously changing function;

[0150] or,

[0151] In the first sub-range, the first step-up / step-down function f Buck-Boost is a constant function that does not exceed the dead zone coefficient, and the second step-up and step-down function g Buck-Boost is a continuously changing function; within the second sub-range, the first step-up / step-down function f Buck-Boost is a continuously changing function, the second step-up / step-down function g Buck-Boost is a constant function that does not exceed the dead zone coefficient.

[0152] In some optional implementations, in the first step-up / down pressure function f Buck-Boost In the case of a continuously changing function, within the range from the first threshold to the third threshold, or within the range from the third threshold to the second threshold, if the input switch tube is a first input switch tube that is not in common with the output side, the first step-up / down function f Buck-Boost is a monotonically increasing function; if the input switch tube is a second input switch tube with a common electrode with the output side, the first step-up and step-down function f Buck-Boost is a monotonically decreasing function;

[0153] In the second buck-boost function g Buck-Boost In the case of a continuously changing function, in the range from the first threshold to the third threshold, or in the range from the third threshold to the second threshold, if the output switch tube is a first output switch tube that is not in common with the input side, the second step-up / step-down function g Buck-Boost is a monotonically decreasing function; if the output switch tube is a second output switch tube with a common electrode with the input side, the second step-up / step-down function g Buck-Boost is a monotonically increasing function.

[0154] In some optional implementations, the first boost function f Boost is a constant function; if the input switch tube is a first input switch tube that is not in common with the output side, according to the first boost function f Boost The determined first duty cycle is a preset maximum duty cycle; if the input switch tube is a second input switch tube with a common electrode with the output side, according to the first boost function f Boost The determined first duty cycle is a preset minimum duty cycle;

[0155] and / or,

[0156] The second step-down function g Buckis a constant function; if the output switch tube is a first output switch tube that is not in common with the input side, according to the second step-down function g Buck The determined second duty cycle is a preset maximum duty cycle; if the output switch tube is a second output switch tube with a common electrode with the input side, according to the second step-down function g Buck The determined second duty cycle is a preset minimum duty cycle.

[0157] In some optional implementations, the value range of the instruction parameter corresponds to a first limit value and a second limit value; the range between the first limit value and the first threshold value is the voltage reduction range, and the range between the second threshold value and the second limit value is the voltage increase range;

[0158] In the first boost function f Boost When the second boost function g is a constant function, Boost is a continuously changing function; and, within the range from the second threshold to the second limit, if the output switch tube is a first output switch tube that is not in common with the input side, the second boost function g Boost is a monotonically decreasing function; if the output switch tube is a second output switch tube with a common electrode with the input side, the second boost function g Boost is a monotonically increasing function;

[0159] In the second step-down function g Buck When the first step-down function f is a constant function, Buck is a continuously changing function; and within the range from the first limit value to the first threshold value, if the input switch tube is a first input switch tube that is not in common with the output side, the first step-down function f Buck is a monotonically increasing function; if the input switch tube is a second input switch tube with a common pole with the output side, the first step-down function f Buck is a monotonically decreasing function.

[0160] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0161] The control device of the buck-boost converter in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, including a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0162] The embodiment of the present invention also provides a computer device having the above Fig.13The control device of the buck-boost converter is shown.

[0163] See also Fig.14 , Fig.14 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Fig.14 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Fig.14 A processor 10 is taken as an example.

[0164] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0165] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0166] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0167] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0168] The computer device further comprises a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0169] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0170] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0171] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A control method for a buck-boost converter, characterized in that: The method comprises: Determine a corresponding instruction parameter according to the difference between the expected value and the actual value of the buck-boost converter; According to the instruction parameter, a first duty cycle of an input switch tube and a second duty cycle of an output switch tube in the buck-boost converter are determined; as the instruction parameter changes, at least one of the first duty cycle and the second duty cycle is adjusted, and within the value range of the instruction parameter, the ratio between the first duty cycle and the second duty cycle changes continuously; The input switch tube is controlled according to the first duty cycle, and the output switch tube is controlled according to the second duty cycle.

2. The method according to claim 1, characterized in that: Determining a first duty cycle of an input switch tube and a second duty cycle of an output switch tube in the buck-boost converter according to the instruction parameter includes: Determine a first duty cycle corresponding to the instruction parameter according to a preset first functional relationship; the first functional relationship is a functional relationship between the instruction parameter and the duty cycle of the input switch tube; According to a preset second functional relationship, a second duty cycle corresponding to the instruction parameter is determined; the second functional relationship is a functional relationship between the instruction parameter and the duty cycle of the output switch tube.

3. The method according to claim 2, characterized in that The value range of the instruction parameter is divided into a step-down range, a step-up / step-down range and a step-up range by a first threshold and a second threshold; The first functional relationship includes a first voltage reduction function f corresponding to the voltage reduction range. Buck , the first step-up / step-down function f corresponding to the step-up / step-down range Buck-Boost The first boost function f corresponding to the boost range Boost ; The second functional relationship includes a second pressure reduction function g corresponding to the pressure reduction range. Buck , the second step-up / step-down function g corresponding to the step-up / step-down range Buck-Boost The second boost function g corresponding to the boost range Boost ; and ， Herein, th1 represents the first threshold, and th2 represents the second threshold.

4. The method according to claim 3, characterized in that Also includes: Pre-set dead zone coefficient; The dead zone coefficient is a value between 0 and 1; When the instruction parameter is within the buck-boost range, the determined first duty cycle and the determined second duty cycle do not exceed the dead zone coefficient.

5. The method according to claim 4, characterized in that The buck-boost range is divided by a third threshold into a first sub-range between the first threshold and the third threshold, and a second sub-range between the third threshold and the second threshold; In the first sub-range, the first step-up / step-down function f Buck-Boost is a continuously changing function, the second step-up / step-down function g Buck-Boost is a constant function that does not exceed the dead zone coefficient; within the second sub-range, the first step-up and step-down function f Buck-Boost is a constant function that does not exceed the dead zone coefficient, and the second step-up and step-down function g Buck-Boost is a continuously changing function; or, In the first sub-range, the first step-up / step-down function f Buck-Boost is a constant function that does not exceed the dead zone coefficient, and the second step-up and step-down function g Buck-Boost is a continuously changing function; within the second sub-range, the first step-up / step-down function f Buck-Boost is a continuously changing function, the second step-up / step-down function g Buck-Boost is a constant function that does not exceed the dead zone coefficient.

6. The method according to claim 5, characterized in that In the first buck-boost function f Buck-Boost In the case of a continuously changing function, within the range from the first threshold to the third threshold, or within the range from the third threshold to the second threshold, if the input switch tube is a first input switch tube (Q1) that is not in common with the output side, the first step-up / down function f Buck-Boost is a monotonically increasing function; if the input switch tube is a second input switch tube (Q2) with a common electrode with the output side, the first step-up / down function f Buck-Boost is a monotonically decreasing function; In the second buck-boost function g Buck-Boost In the case of a continuously changing function, within the range from the first threshold to the third threshold, or within the range from the third threshold to the second threshold, if the output switch tube is a first output switch tube (Q3) that is not in common with the input side, the second step-up / step-down function g Buck-Boost is a monotonically decreasing function; if the output switch tube is a second output switch tube (Q4) with a common electrode with the input side, the second step-up / down function g Buck-Boost is a monotonically increasing function.

7. The method according to any one of claims 3 to 6, characterized in that The first boost function f Boost is a constant function; if the input switch tube is a first input switch tube (Q1) that is not in common with the output side, according to the first boost function f Boost The determined first duty cycle is a preset maximum duty cycle; if the input switch tube is a second input switch tube (Q2) with a common electrode with the output side, according to the first boost function f Boost The determined first duty cycle is a preset minimum duty cycle; and / or, The second step-down function g Buck is a constant function; if the output switch tube is a first output switch tube (Q3) that is not in common with the input side, according to the second step-down function g Buck The determined second duty cycle is a preset maximum duty cycle; if the output switch tube is a second output switch tube (Q4) with a common electrode with the input side, according to the second step-down function g Buck The determined second duty cycle is a preset minimum duty cycle.

8. The method according to claim 7, characterized in that The value range of the instruction parameter corresponds to a first limit value and a second limit value; the range between the first limit value and the first threshold value is the voltage reduction range, and the range between the second threshold value and the second limit value is the voltage increase range; In the first boost function f Boost When the second boost function g is a constant function, Boost is a continuously changing function; and within the range from the second threshold to the second limit, if the output switch tube is a first output switch tube (Q3) that is not in common with the input side, the second boost function g Boost is a monotonically decreasing function; if the output switch tube is a second output switch tube (Q4) with a common electrode with the input side, the second boost function g Boost is a monotonically increasing function; In the second step-down function g Buck When the first step-down function f is a constant function, Buck is a continuously changing function; and within the range from the first limit value to the first threshold value, if the input switch tube is a first input switch tube (Q1) that is not in common with the output side, the first step-down function f Buck is a monotonically increasing function; if the input switch tube is a second input switch tube (Q2) with a common pole with the output side, the first step-down function f Buck is a monotonically decreasing function.

9. A control device for a buck-boost converter, characterized in that: The device comprises: A parameter determination module, used for determining corresponding instruction parameters according to the difference between the expected value and the actual value of the buck-boost converter; a processing module, configured to determine, according to the instruction parameter, a first duty cycle of an input switch tube and a second duty cycle of an output switch tube in the buck-boost converter; as the instruction parameter changes, at least one of the first duty cycle and the second duty cycle is adjusted, and within a value range of the instruction parameter, a ratio between the first duty cycle and the second duty cycle changes continuously; A control module is used to control the input switch tube according to the first duty cycle, and to control the output switch tube according to the second duty cycle.

10. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the control method of the buck-boost converter according to any one of claims 1 to 8 by executing the computer instructions.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the control method of the buck-boost converter according to any one of claims 1 to 8.

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