Non-singular sliding mode control method and device of Buck converter

Abstract

The invention relates to the technical field of automatic control, and discloses a non-singular sliding mode control method and device for a Buck converter, and the method comprises the steps: building a disturbance-based average state equation according to the topological structure and external disturbance conditions of the Buck converter, and enabling the disturbance to comprise load resistance disturbance and input voltage disturbance; an error variable is determined according to the average state equation, a sliding mode controller is constructed according to the error variable, and the sliding mode controller is constructed based on the fractional order exponential reaching law; determining an extended state observer according to the average state equation; and estimating the state and disturbance of the Buck converter according to the extended state observer, and compensating the sliding mode controller according to the state and disturbance estimation condition of the Buck converter.

Description

Technical Field

[0001] This application relates to the field of automatic control technology, specifically to a non-singular sliding mode control method and apparatus for a Buck converter. Background Technology

[0002] In energy router systems, DC load ports typically employ Buck converters to convert voltage levels and supply power to DC loads. Because they are connected to the DC bus, the input voltage is the DC bus voltage, which fluctuates. Additionally, the load resistance is affected by external uncertainties, all of which negatively impact the output voltage stability of the Buck converter. Furthermore, the Buck converter has a slow convergence speed and poor dynamic performance. Summary of the Invention

[0003] This application aims to at least address the technical problems in the related art where, when the load port of an energy router system uses a Buck converter, the output voltage is unstable due to input voltage fluctuations and load changes, and the Buck converter's control has a slow convergence speed, which affects the dynamic performance of the Buck converter.

[0004] To address the aforementioned technical problems, embodiments of this application provide a non-singular sliding mode control method for a Buck converter, comprising:

[0005] Based on the topology of the Buck converter and external disturbances, an average state equation based on disturbances is established, wherein the disturbances include load resistance disturbances and input voltage disturbances;

[0006] The error variable is determined based on the average state equation, and a sliding mode controller is constructed based on the error variable, wherein the sliding mode controller is constructed based on the fractional exponential reaching law;

[0007] The extended state observer is determined based on the average state equation.

[0008] The state and disturbances of the Buck converter are estimated based on the extended state observer, and the sliding mode controller is compensated based on the estimated state and disturbances of the Buck converter.

[0009] In some embodiments, the average state equation is:

[0010] ;

[0011] in, ;

[0012] in, For inductor current, For output voltage, Input voltage, For inductance, For capacitors, For load resistance; Disturbance caused by changes in load resistance. Disturbance caused by input voltage fluctuations. This represents the per-unit value of the load resistance. This is the per-unit value of the input voltage.

[0013] In some embodiments, determining the error variable based on the average state equation includes:

[0014] The estimated values ​​of the input voltage and load resistance of the Buck converter after disturbance are determined based on the average state equation.

[0015] The error variable is determined based on the estimated values ​​of the input voltage and the load resistance.

[0016] The estimated values ​​of the input voltage and the load resistance are as follows:

[0017] ;

[0018] in, This is an estimated value for the input voltage. This is an estimated value for the load resistance;

[0019] The error variable is:

[0020] ;

[0021] ;

[0022] in, , The error variable of the output voltage and its derivative. for The estimated value.

[0023] In some embodiments, constructing a sliding mode controller based on the error variable includes:

[0024] The sliding mode function is determined based on the error variable, the estimated value of the input voltage, and the estimated value of the load resistance;

[0025] Construct a fractional exponential reaching law based on fractional differential operators;

[0026] A sliding mode control function is constructed based on the sliding mode function and the fractional exponential reaching law.

[0027] In some embodiments, determining the sliding mode function based on the error variable, the estimated value of the input voltage, and the estimated value of the load resistance includes:

[0028] Based on the aforementioned error variables and the sliding mode control principle, the sliding surface is determined as follows:

[0029] ;

[0030] Where β is a constant, and , , It is a positive odd number and satisfies ;

[0031] Differentiating the sliding surface based on the error variable, the estimated value of the input voltage, and the estimated value of the load resistance yields the sliding mode function:

[0032] .

[0033] In some embodiments, constructing a fractional exponential reaching law based on a fractional differential operator includes:

[0034] Constructing the first fractional-order reaching law:

[0035] ;

[0036] in, It is a positive real number that approaches zero. , ;

[0037] By introducing the sigmoid function based on the first fractional-order reaching law, we obtain the second fractional-order reaching law:

[0038] ;

[0039] The fractional differential operator is determined as follows:

[0040] ;

[0041] in, and These are the upper and lower limits of the operator. For order, for The real part;

[0042] Based on the second fractional-order convergence law and the fractional-order differential operator, the third fractional-order convergence law is obtained:

[0043] ;

[0044] Differentiating the third fractional-order reaching law yields the fractional-order exponential reaching law:

[0045] ;

[0046] In the formula, ;

[0047] The sliding mode control function constructed based on the sliding mode function and the fractional exponential reaching law is as follows:

[0048] .

[0049] In some embodiments, the first extended state observer constructed based on the load resistance perturbation is:

[0050] ;

[0051] in, This is the estimated output voltage when the load resistance changes. This is an estimate of the load disturbance. , >0 indicates the observer parameter;

[0052] The second extended state observer constructed based on the input voltage perturbation is:

[0053] ;

[0054] in, This is an estimated value of the inductor current under input voltage fluctuations. This is an estimated value of the load resistance under input voltage fluctuations. , >0 represents the observer parameter.

[0055] In some embodiments, the method further includes performing a stability analysis on the sliding mode controller;

[0056] The stability analysis of the sliding mode controller includes:

[0057] The first Lyapunov function is determined as follows:

[0058] ;

[0059] Taking the derivative of the first Lyapunov function and combining it with the sliding mode control function, the stability analysis function of the sliding mode controller is obtained as follows:

[0060] .

[0061] In some embodiments, the method further includes performing a convergence analysis on the extended state observer;

[0062] The convergence analysis of the extended state observer includes:

[0063] Based on the load resistance disturbance and the input voltage disturbance, the error system is determined as follows:

[0064] ;

[0065] ;

[0066] Differentiating the error system based on the extended state observer yields the following result:

[0067] ;

[0068] ;

[0069] The second Lyapunov function for the load resistance disturbance is determined as follows:

[0070] ;

[0071] The convergence analysis of the first extended state observer is performed based on the differential results of the second Lyapunov function and the load resistance perturbation.

[0072] The third Lyapunov function for the input voltage disturbance is determined as follows:

[0073] ;

[0074] The convergence analysis of the second extended state observer is performed based on the third Lyapunov function and the differential result of the input voltage perturbation.

[0075] This application also provides a non-singular sliding mode control device for a Buck converter, including:

[0076] The state equation establishment module is configured to establish an average state equation based on disturbances according to the topology of the Buck converter and external disturbances, wherein the disturbances include load resistance disturbances and input voltage disturbances;

[0077] A sliding mode controller construction module is configured to determine error variables based on the average state equation and construct a sliding mode controller based on the error variables, wherein the sliding mode controller is constructed based on a fractional exponential reaching law;

[0078] An extended state observer determination module is configured to determine an extended state observer based on the average state equation.

[0079] The correction module is configured to estimate the state and disturbance of the Buck converter based on the extended state observer, and to compensate the sliding mode controller based on the estimated state and disturbance of the Buck converter.

[0080] This application also provides an electronic device, including at least a memory and a processor. The memory stores a computer program, and the processor implements the above-described non-singular sliding mode control method for the Buck converter when executing the computer program in the memory.

[0081] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described non-singular sliding mode control method for the Buck converter.

[0082] The non-singular sliding mode control method and apparatus for Buck converters provided in this application establish an average state equation based on disturbances according to the topology and external disturbances of the Buck converter, wherein the disturbances include load resistance disturbances and input voltage disturbances; determine error variables according to the average state equations, and construct a sliding mode controller based on the error variables, wherein the sliding mode controller is constructed based on a fractional-order exponential reaching law; determine an extended state observer according to the average state equations; estimate the state and disturbances of the Buck converter according to the extended state observers, and compensate the sliding mode controller according to the estimated state and disturbances of the Buck converter. This enables fast and accurate tracking of the reference voltage, improves the dynamic performance of the Buck converter, and ensures the stable operation of the energy router system. Attached Figure Description

[0083] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0084] Figure 1 This is a flowchart of a non-singular sliding mode control method for a Buck converter according to an embodiment of this application;

[0085] Figure 2 This is the topology of the Buck converter in an embodiment of this application;

[0086] Figure 3 This is a control block diagram of the Buck converter according to an embodiment of this application;

[0087] Figure 4This is a schematic diagram of the non-singular sliding mode control device of the Buck converter according to an embodiment of this application. Detailed Implementation

[0088] Various embodiments and features of this application are described herein with reference to the accompanying drawings.

[0089] It should be understood that various modifications can be made to the embodiments described herein. Therefore, the above description should not be considered as limiting, but merely as an example of embodiments. Other modifications within the scope and spirit of this application will be apparent to those skilled in the art.

[0090] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0091] These and other features of this application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0092] It should also be understood that although this application has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this application, which have the features described in the claims and are therefore all within the scope of protection defined herein.

[0093] The above and other aspects, features and advantages of this application will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0094] Specific embodiments of this application are described thereafter with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of this application, which can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that could obscure the application. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as the basis and representative basis for the claims to teach those skilled in the art to use this application in a variety of substantially any suitable detailed structures.

[0095] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to this application.

[0096] Due to their high reliability, high efficiency, low cost, and simple structure, DC / DC converters have been widely used in industrial fields such as aerospace, uninterruptible power supplies, automotive manufacturing, and telecommunications equipment. As a typical nonlinear system, DC / DC converters place high demands on the performance and robustness of their voltage tracking controllers.

[0097] Sliding mode control, a commonly used nonlinear control strategy, aims to achieve stable and robust control of a system. It controls the motion of the system state by introducing a specific sliding surface. Its core idea is to enable the system state to slide quickly and accurately onto the sliding surface and remain in motion on that surface. Due to its advantages such as insensitivity to external disturbances, rapid response, strong robustness, and simple physical implementation, it is widely used in robotics, aerospace, and industrial production.

[0098] However, in related technologies, the Buck converter at the load port of the energy router system adopts traditional sliding mode control (such as using the traditional exponential reaching law). Although it can reduce system chattering to a certain extent, its convergence speed is slow, resulting in a slow response speed of the Buck converter and affecting the dynamic performance of the Buck converter. Moreover, sliding mode control is not sensitive to interference, which will have an adverse effect on the output voltage stability of the Buck converter.

[0099] In view of this, embodiments of this application provide a non-singular sliding mode control method, apparatus, electronic device, and storage medium for a Buck converter.

[0100] Example 1

[0101] Figure 1 A flowchart illustrating a non-singular sliding mode control method for a Buck converter according to an embodiment of this application is shown. Figure 1 As shown, this application provides a non-singular sliding mode control method for a Buck converter, including:

[0102] S101: Based on the topology of the Buck converter and external disturbances, establish an average state equation based on disturbances, wherein the disturbances include load resistance disturbances and input voltage disturbances.

[0103] First, according to such Figure 2 The Buck converter topology is shown below. The initial average state equations for the Buck converter are established as follows:

[0104] (1)

[0105] Then, considering that the input of the Buck converter is connected to the DC bus of the energy router system, that is, the input voltage of the Buck converter is the DC bus voltage, and the DC bus voltage fluctuates, and the load resistance will also change due to external uncertainties, the changes caused by the load resistance change and the input voltage fluctuation are substituted as disturbances into the average state equation of the Buck converter, resulting in the following average state equation containing the disturbance:

[0106] (2)

[0107] in, (3)

[0108] in, Disturbance caused by changes in load resistance. Disturbance caused by input voltage fluctuations. This represents the per-unit value of the load resistance. This is the per-unit value of the input voltage.

[0109] S102: Determine the error variable based on the average state equation, and construct a sliding mode controller based on the error variable, wherein the sliding mode controller is constructed based on the fractional exponential reaching law.

[0110] After constructing the average state equation containing the disturbance, a reasonable error variable is determined. Based on the traditional exponential reaching law, a new fractional reaching law is derived by combining fractional-order theory. This new fractional reaching law is the fractional-order exponential reaching law, which can accelerate the convergence speed of the sliding mode controller and improve the dynamic performance of the Buck converter.

[0111] Optionally, in step S102, determining the error variable based on the average state equation includes:

[0112] S201: Determine the estimated value of the input voltage and the estimated value of the load resistance of the Buck converter after being disturbed based on the average state equation;

[0113] S202: Determine the error variable based on the estimated value of the input voltage and the estimated value of the load resistance.

[0114] First, based on equations (1) and (2) above, the estimated values ​​of the input voltage and load resistance of the Buck converter after the actual disturbance are obtained, as shown below:

[0115] (4)

[0116] in, This is an estimated value for the input voltage. This is an estimated value for the load resistance.

[0117] Then, based on the above estimates and the average state equation of the Buck converter containing disturbances, the error between the estimated and actual output voltage values ​​is used as the error variable. The specific error variable is as follows:

[0118] (5)

[0119] (6)

[0120] in, , The error variable of the output voltage and its derivative. for The estimated value.

[0121] Optionally, in step S102, constructing a sliding mode controller based on the error variable includes:

[0122] S301: Determine the sliding mode function based on the error variable, the estimated value of the input voltage, and the estimated value of the load resistance;

[0123] S302: Constructing a fractional exponential reaching law based on fractional differential operators;

[0124] S303: Construct a sliding mode control function based on the sliding mode function and the fractional exponential reaching law.

[0125] When constructing a sliding mode controller, first determine the sliding surface based on the above error variables and the sliding mode control principle:

[0126] (7)

[0127] Where β is a constant, and , , It is a positive odd number and satisfies .

[0128] Then, the sliding surface is differentiated, and the estimated values ​​of the error variable, the input voltage, and the load resistance are substituted into the differential equation to obtain the following sliding function:

[0129] (8)

[0130] In step S302, the fractional exponential reaching law based on the fractional differential operator is constructed, including:

[0131] S3021: Construct the first fractional-order reaching law.

[0132] To accelerate the convergence speed of the sliding mode controller and improve the dynamic performance of the Buck converter, a novel fractional-order reaching law (the first fractional-order reaching law) is derived by combining fractional-order theory with the traditional exponential reaching law. Its expression is shown below:

[0133] (9)

[0134] in, It is a positive real number that approaches zero. , .

[0135] S3022: Based on the first fractional-order reaching law of equation (9), the sigmoid function is introduced to obtain the second fractional-order reaching law. The expression of the second fractional-order reaching law is:

[0136] (10)

[0137] S3023: Determine the fractional differential operator as follows:

[0138] (11)

[0139] in, and These are the upper and lower limits of the operator. For order, for The real part.

[0140] S3024: The third fractional-order reaching law is obtained based on the second fractional-order reaching law and the fractional-order differential operator. The third fractional-order reaching law is obtained according to equations (10) and (11), and its expression is as follows:

[0141] (12)

[0142] In the formula, .

[0143] S3025: Differentiate the third fractional-order reaching law to obtain the fractional-order exponential reaching law.

[0144] Differentiating equation (12) and combining it with equation (11), we can obtain the final fractional-order exponential reaching law, which allows for dynamic and precise adjustment of the sliding mode control reaching speed, thus achieving a fast dynamic response of the Buck converter. Its expression is shown below:

[0145] (13).

[0146] After determining the sliding mode function and constructing the fractional exponential reaching law, the sliding mode control function is constructed according to the sliding mode function in equation (8) and the fractional exponential reaching law in equation (13), and its expression is:

[0147] (14).

[0148] S103: Determine the extended state observer based on the average state equation.

[0149] Since it is difficult to obtain the unknown centralized time-varying perturbation shown in Equation (2), an Extended State Observer (ESO) is introduced in this step to achieve accurate estimation of the state of the Buck converter (e.g., the on / off state of the switch) and the perturbation.

[0150] Based on the extended state observer theory, for load resistance disturbances... and input voltage disturbance You can build an ESO separately.

[0151] The first extended state observer constructed based on load resistance perturbation is:

[0152] (15)

[0153] in, This is the estimated output voltage when the load resistance changes. This is an estimate of the load disturbance. , >0 represents the observer parameter.

[0154] The second extended state observer constructed based on the input voltage perturbation is:

[0155] (16)

[0156] in, This is an estimated value of the inductor current under input voltage fluctuations. This is an estimated value of the load resistance under input voltage fluctuations. , >0 represents the observer parameter.

[0157] S104: Estimate the state and disturbance of the Buck converter based on the extended state observer, and compensate the sliding mode controller based on the estimated state and disturbance of the Buck converter.

[0158] Once the ESO is determined, it can be combined with a sliding mode controller. The sliding mode controller then adjusts the output control quantity μ (e.g., ...) Figure 3 During the control process (as shown), the state and disturbance of the Buck converter are estimated based on the ESO, and the control quantity is dynamically compensated in a timely manner based on the expanded state quantity. This can effectively solve the problem of output voltage instability caused by input voltage fluctuations and load changes, and quickly and accurately track the reference voltage.

[0159] In this embodiment, the sliding mode control algorithm is improved by using a non-singular sliding surface combined with a novel fractional-order reaching law, which can achieve fast convergence with high tracking accuracy of Buck converter sliding mode control, effectively eliminate system chattering of the energy router system, reduce system tracking error, improve system tracking accuracy, and ensure stable operation of the energy router system.

[0160] The non-singular sliding mode control method for Buck converters provided in this application establishes an average state equation based on disturbances, including load resistance disturbances and input voltage disturbances, according to the topology and external disturbances of the Buck converter. An error variable is determined based on the average state equation, and a sliding mode controller is constructed based on the error variable, wherein the sliding mode controller is constructed based on a fractional-order exponential reaching law. An extended state observer is determined based on the average state equation. The state and disturbances of the Buck converter are estimated based on the extended state observer, and the sliding mode controller is compensated based on the estimated state and disturbances of the Buck converter. This method enables rapid and accurate tracking of the reference voltage, improves the dynamic performance of the Buck converter, and ensures the stable operation of the energy router system.

[0161] In some embodiments, the method further includes performing a stability analysis on the sliding mode controller, specifically including:

[0162] S401: Determine the first Lyapunov function as:

[0163] (17);

[0164] S402: Taking the derivative of the first Lyapunov function and combining it with the sliding mode control function, the stability analysis function of the sliding mode controller is obtained as follows:

[0165] (18).

[0166] because Therefore, it is easy to obtain Because of the first Lyapunov function Therefore, in Under the given conditions, the system satisfies the Lyapunov stability condition, such that the system voltage error state estimate is... and It can converge to the sliding surface in a finite time, and then converge to the equilibrium state in a finite time.

[0167] In some embodiments, the method further includes performing convergence analysis on the extended state observer, specifically including:

[0168] S501: Based on the load resistance disturbance and the input voltage disturbance, the error system is determined as follows:

[0169] (19)

[0170] (20)

[0171] S502: Differentiate the error system based on the extended state observer to obtain the differential result:

[0172] (twenty one)

[0173] (twenty two)

[0174] S503: Determine the second Lyapunov function of the load resistance disturbance as follows:

[0175] (twenty three)

[0176] The convergence analysis of the first extended state observer is performed based on the differential results of the second Lyapunov function and the load resistance perturbation.

[0177] right Taking the derivative, we get:

[0178] (twenty four)

[0179] Substituting equation (21) into equation (24), we get:

[0180] (25)

[0181] S504: Determine the third Lyapunov function of the input voltage disturbance as:

[0182] (26)

[0183] The convergence analysis of the second extended state observer is performed based on the third Lyapunov function and the differential result of the input voltage perturbation.

[0184] right Taking the derivative, we get:

[0185] (27)

[0186] Substituting equation (22) into equation (27), we get:

[0187] (28).

[0188] To facilitate the theoretical analysis of the convergence of the extended state observer, we assume a perturbation. and If it is bounded, then it exists. , And because in equations (25) and (28), , Therefore, error systems (19) and (20) are ISS stable. At this point, note that... , , , This indicates that the error system will converge to zero in a finite amount of time.

[0189] Based on the above feasibility analysis (including the stability analysis of the sliding mode controller and the convergence analysis of the extended state observer), it can be seen that the sliding mode controller and extended state observer provided in this application embodiment are effective and feasible, and can achieve fast and accurate tracking of the reference voltage of the Buck converter, ensuring the stable operation of the energy router system.

[0190] Example 2

[0191] Figure 4 A schematic diagram of the non-singular sliding mode control device of the Buck converter according to an embodiment of this application is shown. Figure 4 As shown in the embodiments of this application, a non-singular sliding mode control device for a Buck converter is also provided, comprising:

[0192] The state equation establishment module 10 is configured to establish an average state equation based on disturbances according to the topology of the Buck converter and external disturbances, wherein the disturbances include load resistance disturbances and input voltage disturbances;

[0193] The sliding mode controller construction module 20 is configured to determine the error variable according to the average state equation and construct the sliding mode controller according to the error variable, wherein the sliding mode controller is constructed based on the fractional exponential reaching law;

[0194] Extended state observer determination module 30 is configured to determine an extended state observer based on the average state equation;

[0195] The correction module 40 is configured to estimate the state and disturbance of the Buck converter based on the extended state observer, and to compensate the sliding mode controller based on the estimated state and disturbance of the Buck converter.

[0196] In some embodiments, the average state equation is:

[0197] ;

[0198] in, ;

[0199] in, For inductor current, For output voltage, Input voltage, For inductance, For capacitors, For load resistance; Disturbance caused by changes in load resistance. Disturbance caused by input voltage fluctuations. This represents the per-unit value of the load resistance. This is the per-unit value of the input voltage.

[0200] In some embodiments, the sliding mode controller construction module 20 is further configured to:

[0201] The estimated values ​​of the input voltage and load resistance of the Buck converter after disturbance are determined based on the average state equation.

[0202] The error variable is determined based on the estimated values ​​of the input voltage and the load resistance.

[0203] The estimated values ​​of the input voltage and the load resistance are as follows:

[0204] ;

[0205] in, This is an estimated value for the input voltage. This is an estimated value for the load resistance;

[0206] The error variable is:

[0207] ;

[0208] ;

[0209] in, , The error variable of the output voltage and its derivative. for The estimated value.

[0210] In some embodiments, the sliding mode controller construction module 20 is further configured to:

[0211] The sliding mode function is determined based on the error variable, the estimated value of the input voltage, and the estimated value of the load resistance;

[0212] Construct a fractional exponential reaching law based on fractional differential operators;

[0213] A sliding mode control function is constructed based on the sliding mode function and the fractional exponential reaching law.

[0214] In some embodiments, the sliding mode controller construction module 20 is further configured to:

[0215] Based on the aforementioned error variables and the sliding mode control principle, the sliding surface is determined as follows:

[0216] ;

[0217] Where β is a constant, and , , It is a positive odd number and satisfies ;

[0218] Differentiating the sliding surface based on the error variable, the estimated value of the input voltage, and the estimated value of the load resistance yields the sliding mode function:

[0219] .

[0220] In some embodiments, the sliding mode controller construction module 20 is further configured to:

[0221] Constructing the first fractional-order reaching law:

[0222] ;

[0223] in, It is a positive real number that approaches zero. , ;

[0224] By introducing the sigmoid function based on the first fractional-order reaching law, we obtain the second fractional-order reaching law:

[0225] ;

[0226] The fractional differential operator is determined as follows:

[0227] ;

[0228] in, and These are the upper and lower limits of the operator. For order, for The real part;

[0229] Based on the second fractional-order convergence law and the fractional-order differential operator, the third fractional-order convergence law is obtained:

[0230] ;

[0231] Differentiating the third fractional-order reaching law yields the fractional-order exponential reaching law:

[0232] ;

[0233] In the formula, ;

[0234] The sliding mode control function constructed based on the sliding mode function and the fractional exponential reaching law is as follows:

[0235] .

[0236] In some embodiments, the first extended state observer constructed based on the load resistance perturbation is:

[0237] ;

[0238] in, This is the estimated output voltage when the load resistance changes. This is an estimate of the load disturbance. , >0 indicates the observer parameter;

[0239] The second extended state observer constructed based on the input voltage perturbation is:

[0240] ;

[0241] in, This is an estimated value of the inductor current under input voltage fluctuations. This is an estimated value of the load resistance under input voltage fluctuations. , >0 represents the observer parameter.

[0242] In some embodiments, the non-singular sliding mode control device for the Buck converter further includes a feasibility analysis module configured to perform stability analysis on the sliding mode controller;

[0243] The stability analysis of the sliding mode controller includes:

[0244] The first Lyapunov function is determined as follows:

[0245] ;

[0246] Taking the derivative of the first Lyapunov function and combining it with the sliding mode control function, the stability analysis function of the sliding mode controller is obtained as follows:

[0247] .

[0248] In some embodiments, the feasibility analysis module is further configured to perform convergence analysis on the extended state observer;

[0249] The convergence analysis of the extended state observer includes:

[0250] Based on the load resistance disturbance and the input voltage disturbance, the error system is determined as follows:

[0251] ;

[0252] ;

[0253] Differentiating the error system based on the extended state observer yields the following result:

[0254] ;

[0255] ;

[0256] The second Lyapunov function for the load resistance disturbance is determined as follows:

[0257] ;

[0258] The convergence analysis of the first extended state observer is performed based on the differential results of the second Lyapunov function and the load resistance perturbation.

[0259] The third Lyapunov function for the input voltage disturbance is determined as follows:

[0260] ;

[0261] The convergence analysis of the second extended state observer is performed based on the third Lyapunov function and the differential result of the input voltage perturbation.

[0262] The non-singular sliding mode control device for the Buck converter provided in this application corresponds to the non-singular sliding mode control method for the Buck converter in the above embodiments. Any option in the embodiments of the non-singular sliding mode control method for the Buck converter is also applicable to the embodiments of the non-singular sliding mode control device for the Buck converter, and will not be repeated here.

[0263] Example 3

[0264] This application also provides an electronic device, including at least a memory and a processor. The memory stores a computer program, and the processor implements the above-described non-singular sliding mode control method for the Buck converter when executing the computer program in the memory.

[0265] In some embodiments, the processor executing a computer program may be a processing device that includes one or more general-purpose processing devices, such as a microprocessor, a central processing unit (CPU), a graphics processing unit (GPU), etc. More specifically, the processor may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor that runs other instruction sets, or a processor that runs a combination of instruction sets. The processor may also be one or more special-purpose processing devices, such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), system-on-a-chip (SoCs), etc.

[0266] The memory may be a read-only memory (ROM), random access memory (RAM), phase-change random access memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), electrically erasable programmable read-only memory (EEPROM), other types of random access memory (RAM), flash drives or other forms of flash memory, cache, registers, static memory, optical disc read-only memory (CD-ROM), digital versatile optical disc (DVD) or other optical storage, magnetic tape cassette or other magnetic storage devices, or any other possible non-transitory medium used to store information or instructions that can be accessed by computer equipment.

[0267] The electronic devices in this application embodiment may include, but are not limited to, fixed terminal devices such as servers, desktop computers, and digital TVs, as well as mobile terminal devices such as in-vehicle devices (e.g., head-up displays), handheld devices (e.g., mobile phones, tablets, etc.), and wearable devices (e.g., smartwatches, smart bracelets, etc.).

[0268] Example 4

[0269] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described non-singular sliding mode control method for the Buck converter.

[0270] The computer-readable storage medium in this application embodiment can be any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. In this application embodiment, the computer-readable storage medium can be any tangible medium containing or storing a computer program that can be used by or in conjunction with an instruction execution system, apparatus, or device; for example, it can be the aforementioned memory.

[0271] The computer programs of embodiments of this application can be organized into one or more computer-executable components or modules. Various aspects of this application can be implemented with any number and combination of such components or modules. For example, aspects of this application are not limited to the specific computer-executable instructions or specific components or modules shown in the drawings and described herein. Other embodiments may include different computer-executable instructions or components having more or fewer functions than those shown and described herein.

[0272] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A non-singular sliding mode control method for a Buck converter, characterized in that, include: Based on the topology of the Buck converter and external disturbances, an average state equation based on disturbances is established, wherein the disturbances include load resistance disturbances and input voltage disturbances; The error variable is determined based on the average state equation, and a sliding mode controller is constructed based on the error variable, wherein the sliding mode controller is constructed based on the fractional exponential reaching law; The extended state observer is determined based on the average state equation. The state and disturbances of the Buck converter are estimated based on the extended state observer, and the sliding mode controller is compensated based on the estimated state and disturbances of the Buck converter.

2. The method according to claim 1, characterized in that, The average state equation is: ； in, ; in, For inductor current, For output voltage, Input voltage, For inductance, For capacitors, For load resistance; Disturbance caused by changes in load resistance. Disturbance caused by input voltage fluctuations. This represents the per-unit value of the load resistance. This is the per-unit value of the input voltage.

3. The method according to claim 2, characterized in that, The error variables determined based on the average state equation include: The estimated values ​​of the input voltage and load resistance of the Buck converter after disturbance are determined based on the average state equation. The error variable is determined based on the estimated values ​​of the input voltage and the load resistance. The estimated values ​​of the input voltage and the load resistance are as follows: ； in, This is an estimated value for the input voltage. This is an estimated value for the load resistance; The error variable is: ； ； in, , The error variable of the output voltage and its derivative. for The estimated value.

4. The method according to claim 3, characterized in that, Constructing a sliding mode controller based on the error variables includes: The sliding mode function is determined based on the error variable, the estimated value of the input voltage, and the estimated value of the load resistance; Construct a fractional exponential reaching law based on fractional differential operators; A sliding mode control function is constructed based on the sliding mode function and the fractional exponential reaching law.

5. The method according to claim 4, characterized in that, The sliding mode function is determined based on the error variable, the estimated value of the input voltage, and the estimated value of the load resistance, including: Based on the aforementioned error variables and the sliding mode control principle, the sliding surface is determined as follows: ； Where β is a constant, and , , It is a positive odd number and satisfies ; Differentiating the sliding surface based on the error variable, the estimated value of the input voltage, and the estimated value of the load resistance yields the sliding mode function: 。 6. The method according to claim 5, characterized in that, Constructing fractional exponential reaching laws based on fractional differential operators, including: Constructing the first fractional-order reaching law: ； in, It is a positive real number that approaches zero. , ; By introducing the sigmoid function based on the first fractional-order reaching law, we obtain the second fractional-order reaching law: ； The fractional differential operator is determined as follows: ； in, and These are the upper and lower limits of the operator. For order, for The real part; Based on the second fractional-order convergence law and the fractional-order differential operator, the third fractional-order convergence law is obtained: ； Differentiating the third fractional-order reaching law yields the fractional-order exponential reaching law: ； In the formula, ; The sliding mode control function constructed based on the sliding mode function and the fractional exponential reaching law is as follows: 。 7. The method according to claim 2, characterized in that, The first extended state observer constructed based on load resistance perturbation is: ； in, This is the estimated output voltage when the load resistance changes. This is an estimate of the load disturbance. , >0 indicates the observer parameter; The second extended state observer constructed based on the input voltage perturbation is: ； in, This is an estimated value of the inductor current under input voltage fluctuations. This is an estimated value of the load resistance under input voltage fluctuations. , >0 represents the observer parameter.

8. The method according to claim 6, characterized in that, The method further includes performing stability analysis on the sliding mode controller; The stability analysis of the sliding mode controller includes: The first Lyapunov function is determined as follows: ； Taking the derivative of the first Lyapunov function and combining it with the sliding mode control function, the stability analysis function of the sliding mode controller is obtained as follows: 。 9. The method according to claim 7, characterized in that, The method further includes performing convergence analysis on the extended state observer; The convergence analysis of the extended state observer includes: Based on the load resistance disturbance and the input voltage disturbance, the error system is determined as follows: ； ； Differentiating the error system based on the extended state observer yields the following result: ； ； The second Lyapunov function for the load resistance disturbance is determined as follows: ； The convergence analysis of the first extended state observer is performed based on the differential results of the second Lyapunov function and the load resistance perturbation. The third Lyapunov function for the input voltage disturbance is determined as follows: ； The convergence analysis of the second extended state observer is performed based on the third Lyapunov function and the differential result of the input voltage perturbation.

10. A non-singular sliding mode control device for a Buck converter, characterized in that, include: The state equation establishment module is configured to establish an average state equation based on disturbances according to the topology of the Buck converter and external disturbances, wherein the disturbances include load resistance disturbances and input voltage disturbances; A sliding mode controller construction module is configured to determine error variables based on the average state equation and construct a sliding mode controller based on the error variables, wherein the sliding mode controller is constructed based on a fractional exponential reaching law; An extended state observer determination module is configured to determine an extended state observer based on the average state equation. The correction module is configured to estimate the state and disturbance of the Buck converter based on the extended state observer, and to compensate the sliding mode controller based on the estimated state and disturbance of the Buck converter.

Images