MMC low-voltage stability control method based on linear active disturbance rejection

Abstract

The invention relates to an MMC low-voltage stability control method based on linear active disturbance rejection. The method comprises the following steps: acquiring voltage outer loop parameters in a linear active disturbance rejection model; determining current inner loop component reference data of the MMC according to the voltage outer loop parameter; determining a stable state judgment result of the MMC according to the current inner ring component reference data; and under the condition that the stable state judgment result indicates that the MMC is in the unstable state, performing stability control on the MMC. By adopting the method, a stable state judgment result based on linear active disturbance rejection control can be accurately obtained, so that the stability of the MMC can be reliably controlled.

Description

Technical Field

[0001] This application relates to the field of power distribution network control technology, and in particular to a low voltage stability control method based on linear active disturbance rejection (AMC). Background Technology

[0002] Modular multilevel converters (MMCs) are core equipment for long-distance power transmission and grid interconnection of new energy sources. Their stability under low-voltage conditions (such as grid short circuits and voltage drops) has become a key bottleneck restricting the safe operation of the system.

[0003] Currently, most MMC DC voltage outer loops use PI controllers. Their integral circuits are prone to dynamic response lag under low voltage and large disturbances, which exacerbates voltage fluctuations and current surges, leading to an increased risk of system transient instability and making it difficult to adapt to wide range of voltage disturbance scenarios.

[0004] Therefore, how to effectively control the stability of MMC under low voltage conditions is a problem worthy of attention. Summary of the Invention

[0005] Therefore, it is necessary to provide a linear active disturbance rejection (AID)-based low-voltage stability control method for MMC that can effectively control the stability of MMC under low-voltage conditions, addressing the aforementioned technical problems.

[0006] In a first aspect, this application provides a low-voltage stability control method for MMC based on linear active disturbance rejection, applied to MMC controlled based on a pre-built linear active disturbance rejection model, including:

[0007] Obtain the voltage outer loop parameters in the linear active disturbance rejection model;

[0008] Based on the outer voltage loop parameters, determine the reference data for the inner current loop component of the MMC;

[0009] Based on the reference data of the inner current loop component, the steady state judgment result of MMC is determined;

[0010] When the stability assessment result indicates that the MMC is in an unstable state, stability control is performed on the MMC.

[0011] In one embodiment, determining the reference data of the current inner loop component of the MMC based on the voltage outer loop parameters includes: substituting the voltage outer loop parameters into the linear active disturbance rejection model to obtain the reference data of the current inner loop component of the MMC.

[0012] In one embodiment, the voltage outer loop parameters include the voltage outer loop control gain and the disturbance amount; correspondingly, obtaining the voltage outer loop parameters in the linear active disturbance rejection model includes: determining the correspondence between the DC side voltage and current components in the MMC; and determining the voltage outer loop parameters in the linear active disturbance rejection model based on the correspondence.

[0013] In one embodiment, determining the voltage outer loop parameters in the linear active disturbance rejection model based on the correspondence includes: determining the voltage outer loop control gain based on the coefficients of the current components contained in the correspondence; and determining the disturbance amount based on the intercept contained in the correspondence.

[0014] In one embodiment, the voltage outer loop parameters also include the linear state error feedback output; correspondingly, obtaining the voltage outer loop parameters in the linear active disturbance rejection model includes: obtaining the voltage outer loop reference value and DC-side bus voltage during the operation of the MMC; and determining the linear state error feedback output based on the voltage outer loop reference value, the DC-side bus voltage, and a preset error feedback proportional coefficient.

[0015] In one embodiment, determining the correspondence between the DC-side voltage and current components in the MMC includes: obtaining a first relationship between the current components and the AC-side power in the MMC, and a second relationship between the DC-side voltage and the DC-side power in the MMC; and determining the correspondence between the DC-side voltage and current components based on the first and second relationships.

[0016] Secondly, this application also provides a low-voltage stability control device for MMC based on linear active disturbance rejection, comprising:

[0017] The acquisition module is used to acquire the voltage outer loop parameters in the linear active disturbance rejection model;

[0018] The first determining module is used to determine the reference data of the current inner loop component of MMC based on the voltage outer loop parameters;

[0019] The second determining module is used to determine the steady state judgment result of MMC based on the reference data of the inner current loop component.

[0020] The control module is used to perform stability control on the MMC when the stability judgment result indicates that the MMC is in an unstable state.

[0021] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0022] Obtain the voltage outer loop parameters in the linear active disturbance rejection model;

[0023] Based on the outer voltage loop parameters, determine the reference data for the inner current loop component of the MMC;

[0024] Based on the reference data of the inner current loop component, the steady state judgment result of MMC is determined;

[0025] When the stability assessment result indicates that the MMC is in an unstable state, stability control is performed on the MMC.

[0026] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0027] Obtain the voltage outer loop parameters in the linear active disturbance rejection model;

[0028] Based on the outer voltage loop parameters, determine the reference data for the inner current loop component of the MMC;

[0029] Based on the reference data of the inner current loop component, the steady state judgment result of MMC is determined;

[0030] When the stability assessment result indicates that the MMC is in an unstable state, stability control is performed on the MMC.

[0031] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0032] Obtain the voltage outer loop parameters in the linear active disturbance rejection model;

[0033] Based on the outer voltage loop parameters, determine the reference data for the inner current loop component of the MMC;

[0034] Based on the reference data of the inner current loop component, the steady state judgment result of MMC is determined;

[0035] When the stability assessment result indicates that the MMC is in an unstable state, stability control is performed on the MMC.

[0036] The aforementioned low-voltage stability control method for MMC based on linear active disturbance rejection (ADR) includes: acquiring the voltage outer loop parameters in the linear ADR model; determining the reference data of the current inner loop component of the MMC based on the voltage outer loop parameters; determining the stability judgment result of the MMC based on the current inner loop component reference data; and performing stability control on the MMC when the stability judgment result indicates that the MMC is in an unstable state. By determining the reference data of the current inner loop component controlled based on the pre-constructed linear ADR model, the above method can accurately obtain the stability judgment result based on linear ADR control, thereby enabling reliable stability control of the MMC. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is an application environment diagram of an MMC low-voltage stability control method based on linear active disturbance rejection in one embodiment;

[0039] Figure 2 This is a flowchart illustrating a linear active disturbance rejection (ANR)-based MMC low-voltage stability control method in one embodiment.

[0040] Figure 3 This is a schematic diagram of the structure of MMC based on linear active disturbance rejection model control in one embodiment;

[0041] Figure 4 In one embodiment, 'a' is the ratio of the error feedback scaling factor 'k'. p A schematic diagram illustrating the changing pattern;

[0042] Figure 5 This is a flowchart illustrating the MMC low-voltage stability control method based on linear active disturbance rejection in another embodiment.

[0043] Figure 6 This is a block diagram of a linear active disturbance rejection (AMC) low voltage stability control device in one embodiment.

[0044] Figure 7 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0046] The MMC low-voltage stability control method based on linear active disturbance rejection provided in this application embodiment can be applied to, for example... Figure 1In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be integrated onto server 104, or it can be located in the cloud or on other network servers. Server 104 can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services.

[0047] In one exemplary embodiment, such as Figure 2 As shown, a low-voltage stability control method for MMC based on linear active disturbance rejection is provided, which is then applied to... Figure 1 The above-described MMC low-voltage stability control method based on linear active disturbance rejection (ADR) is applied to an MMC controlled by a pre-built linear ADR model, and includes the following steps:

[0048] S210, obtain the voltage outer loop parameters in the linear active disturbance rejection model.

[0049] Among them, the voltage outer loop parameters can be understood as the various parameters of the voltage outer loop based on linear active disturbance rejection.

[0050] Specifically, the voltage outer loop parameters may include the DC voltage outer loop input, the DC voltage outer loop output, the voltage outer loop control gain, and the disturbance.

[0051] Among them, the linear active disturbance rejection model can be understood as a mathematical model built on the linear active disturbance rejection theory.

[0052] The linear active disturbance rejection model can include the mathematical model corresponding to the linear tracking differentiator, the mathematical model corresponding to the linear extended state observer, and the mathematical model corresponding to the linear state error feedback.

[0053] Specifically, based on the linear active disturbance rejection theory, the mathematical model corresponding to the linear tracking differentiator can be expressed as:

[0054]

[0055] Where u represents the system input and y represents the system output; y represents the partial derivative of y; b0 represents the known outer loop control gain of the voltage; f represents the total disturbance of the system, which includes internal disturbances caused by factors such as component characteristics and parameter changes, as well as various uncertain disturbances from the external environment.

[0056] Specifically, the mathematical model corresponding to the linearly extended state observer can be expressed as:

[0057]

[0058] Where β1 and β2 both represent the observer gain coefficients, b0 represents the voltage outer loop control gain, z1 represents the real-time observed value of the system output y, and z2 represents the real-time estimate of internal and external disturbances of the system, quantifying difficult-to-measure and complex disturbances into observable variables.

[0059] The linear extended state observer enables real-time observation of the system output y and the total disturbance f of internal and external disturbances.

[0060] Specifically, the mathematical model corresponding to linear state error feedback can be expressed as:

[0061]

[0062] Where u0 represents the linear state error feedback output; k p It is represented by the error feedback proportional coefficient; r represents the given reference value.

[0063] Linear state error feedback control introduces an error feedback proportional coefficient k p This can improve the system's transient response capability.

[0064] In an optional embodiment, the voltage outer loop parameters in the linear active disturbance rejection model can be obtained by characterizing the voltage outer loop quantities based on the structure of the MMC under linear active disturbance rejection model control. See also Figure 3 A schematic diagram of the structure of MMC based on linear active disturbance rejection model control is shown.

[0065] In an optional embodiment, when the voltage outer loop parameters include the voltage outer loop control gain and the disturbance amount, obtaining the voltage outer loop parameters in the linear active disturbance rejection model can include: determining the correspondence between the DC side voltage and current components in the MMC; and determining the voltage outer loop parameters in the linear active disturbance rejection model based on the correspondence.

[0066] The current component can be understood as the reference value of the d-axis component of the current.

[0067] The correspondence between the DC-side voltage and current components in the MMC can be obtained based on the AC-side power and DC-side power of the MMC.

[0068] In one optional embodiment, based on the structure of the MMC, the AC-side power and DC-side power of the MMC are obtained:

[0069]

[0070] in, Indicates AC side power; Indicates DC-side power; Cdc Represented as the equivalent capacitance on the DC side of the MMC; I dc Represented as the DC-side bus current of the MMC, V dc Represented as DC-side bus voltage; v sd This represents the d-axis component of the AC output voltage after Park transformation; v sq This represents the q-axis component of the AC output voltage after Park transformation; i dc This is expressed as the DC-side current of the MMC; Represented as the d-axis component of the current; It is represented as the q-axis component of the current.

[0071] Based on the AC-side power and DC-side power of the MMC, the first relationship between the current component and the AC-side power in the MMC, and the second relationship between the DC-side voltage and the DC-side power in the MMC can be obtained.

[0072] Based on the first and second relationships, the correspondence between the DC side voltage and current components can be determined.

[0073] In practical implementation, the internal power loss of the MMC system, i.e., P, is ignored. dc ≈P ac When the MMC system is running stably, the voltage V is approximately assumed to be... dc ≈V dcref Current ≈i dref From this, the DC side voltage V can be obtained. dc With d-axis current i dref The relationship between them:

[0074]

[0075] In one alternative embodiment, the voltage outer loop control gain can be determined based on the coefficients of the current components contained in the correspondence; and the disturbance amount can be determined based on the intercept contained in the correspondence.

[0076] In practical implementation, the voltage outer loop control gain can be set to b0 = 3V. sd / (2C dc V dcref Let the disturbance be represented as f = –I. dc / C dc .

[0077] In an optional embodiment, if the voltage outer loop parameters also include the linear state error feedback output, then obtaining the voltage outer loop parameters in the linear active disturbance rejection model may include: obtaining the voltage outer loop reference value and DC-side bus voltage of the MMC during operation; and determining the linear state error feedback output based on the voltage outer loop reference value, the DC-side bus voltage, and a preset error feedback proportional coefficient.

[0078] In practice, the outer voltage loop reference value can be the DC bus voltage command V. dcref The DC bus voltage is V. dc The linear state error feedback output can be obtained as follows:

[0079]

[0080]

[0081] In one alternative embodiment, after determining the voltage outer loop control gain and disturbance amount, the voltage outer loop parameters in the linear active disturbance rejection model can also be obtained as follows:

[0082] Let the voltage outer loop control gain be b0 = 3V sd / (2C dc V dcref Let the disturbance be represented as f = –I. dc / C dc The error feedback and disturbance compensation mechanism is designed as follows:

[0083]

[0084] Furthermore, the parameters of the voltage outer loop of the linear active disturbance rejection system can be expressed as:

[0085]

[0086] Based on linear active disturbance rejection (AMC) control, the parameters of the voltage outer loop in the linear AMRC model are further expressed as follows:

[0087]

[0088] S220, based on the voltage outer loop parameters, determines the reference data for the current inner loop component of the MMC.

[0089] Among them, the current inner loop component reference data can be understood as the current inner loop component reference data based on the MMC under linear active disturbance rejection model control.

[0090] In one alternative embodiment, reference data for the inner current component of the MMC can be determined based on the outer voltage loop parameters and the linear active disturbance rejection model. That is, the outer voltage loop parameters are substituted into the linear active disturbance rejection model to obtain the reference data for the inner current component of the MMC.

[0091] In practical implementation, the outer voltage loop parameters can be substituted into the mathematical model corresponding to the linear state error feedback in the linear active disturbance rejection model to obtain the reference data of the inner current loop components.

[0092] In practical implementation, the reference data for the inner current loop component can be obtained according to the following formula:

[0093]

[0094] S230, based on the reference data of the inner current loop component, determines the steady state judgment result of MMC.

[0095] In practical implementation, the stability judgment result of MMC can be determined based on the reference data of the inner current component and the preset stability discrimination formula of MMC based on linear active disturbance rejection control.

[0096] The preset stability criterion for MMC based on linear active disturbance rejection control can be expressed as:

[0097]

[0098] make:

[0099]

[0100] Substituting the reference data of the inner current loop component into the above discriminant, if a is greater than 0, it indicates that the MMC is in a stable state; if a is less than or equal to 0, it indicates that the MMC is in an unstable state.

[0101] S240, when the stability judgment result indicates that the MMC is in an unstable state, performs stability control on the MMC.

[0102] It is important to note here that the magnitude of 'a' is related to the error feedback scaling factor 'k'. p Related to. k p The larger the value of 'a', the smaller 'a', and the worse the stability of the MMC system. Here, 'a' is related to the error feedback proportionality coefficient 'k'. p The pattern of change can be found in [reference]. Figure 4 .

[0103] If the steady-state judgment result indicates that the MMC is in an unstable state, the stability of the MMC can be controlled by adjusting the error feedback proportional coefficient.

[0104] The aforementioned low-voltage stability control method for MMC based on linear active disturbance rejection (ADR) includes: acquiring the voltage outer loop parameters in the linear ADR model; determining the reference data of the current inner loop component of the MMC based on the voltage outer loop parameters; determining the stability judgment result of the MMC based on the current inner loop component reference data; and performing stability control on the MMC when the stability judgment result indicates that the MMC is in an unstable state. By determining the reference data of the current inner loop component controlled based on the pre-constructed linear ADR model, the above method can accurately obtain the stability judgment result based on linear ADR control, thereby enabling reliable stability control of the MMC.

[0105] Based on the technical solutions of the above embodiments, this application also provides an optional embodiment, in which the MMC low voltage stability control method based on linear active disturbance rejection will be described in detail.

[0106] See Figure 5 The MMC low-voltage stability control method based on linear active disturbance rejection shown includes the following steps:

[0107] S501, based on the structure of the MMC, obtain the AC side power and DC side power of the MMC.

[0108] S502, based on the AC-side power and DC-side power of the MMC, obtain the first relationship between the current component and the AC-side power in the MMC, and the second relationship between the DC-side voltage and the DC-side power in the MMC.

[0109] S503, based on the first and second relationships, can determine the correspondence between the DC side voltage and current components.

[0110] S504 determines the voltage outer loop control gain based on the coefficients of the current components contained in the correspondence; and determines the disturbance amount based on the intercept contained in the correspondence.

[0111] S505 substitutes the linear state error feedback output, voltage outer loop control gain, and disturbance quantity into the mathematical model corresponding to the linear state error feedback in the linear active disturbance rejection model to obtain the reference data of the current inner loop component.

[0112] In one optional embodiment, the linear state error feedback output can be determined based on the outer loop voltage reference value of the MMC during operation, the DC bus voltage, and a preset error feedback proportional coefficient.

[0113] S506, based on the reference data of the inner current loop component and the preset stability discrimination formula of the MMC based on linear active disturbance rejection control, determine the stability state judgment result of the MMC.

[0114] S507, when the stability judgment result indicates that the MMC is in an unstable state, performs stability control on the MMC.

[0115] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0116] Based on the same inventive concept, this application also provides a linear active disturbance rejection (LAID) based MMC low-voltage stability control device for implementing the aforementioned linear active disturbance rejection (LAID) based MMC low-voltage stability control method. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more LID based MMC low-voltage stability control embodiments provided below can be found in the limitations of the linear active disturbance rejection (LAID) based MMC low-voltage stability control method described above, and will not be repeated here.

[0117] In one exemplary embodiment, such as Figure 6 As shown, a low-voltage stability control device for MMC based on linear active disturbance rejection is provided, comprising: an acquisition module 610, a first determination module 620, a second determination module 630, and a control module 640, wherein:

[0118] The acquisition module 610 is used to acquire the voltage outer loop parameters in the linear active disturbance rejection model;

[0119] The first determining module 620 is used to determine the reference data of the current inner loop component of MMC based on the voltage outer loop parameters;

[0120] The second determining module 630 is used to determine the steady state judgment result of MMC based on the reference data of the inner current loop component.

[0121] The control module 640 is used to perform stability control on the MMC when the stability judgment result indicates that the MMC is in an unstable state.

[0122] In one embodiment, the first determining module 620 is specifically used to: substitute the voltage outer loop parameters into the linear active disturbance rejection model to obtain reference data of the current inner loop component of the MMC controlled by the linear active disturbance rejection model.

[0123] In one embodiment, the voltage outer loop parameters include the voltage outer loop control gain and the disturbance amount; accordingly, the acquisition module 610 is specifically used to: determine the correspondence between the DC side voltage and current components in the MMC; and determine the voltage outer loop parameters in the linear active disturbance rejection model based on the correspondence.

[0124] In one embodiment, the acquisition module 610 is specifically used to: determine the voltage outer loop control gain based on the coefficients of the current components contained in the correspondence; and determine the disturbance amount based on the intercept contained in the correspondence.

[0125] In one embodiment, the voltage outer loop parameters also include the linear state error feedback output; correspondingly, the acquisition module 610 is specifically used to: acquire the voltage outer loop reference value and DC-side bus voltage of the MMC during operation; and determine the linear state error feedback output based on the voltage outer loop reference value, the DC-side bus voltage, and the preset error feedback ratio coefficient.

[0126] In one embodiment, the acquisition module 610 is specifically used to: acquire a first relationship between the current component and the AC side power in the MMC, and a second relationship between the DC side voltage and the DC side power in the MMC; and determine the correspondence between the DC side voltage and the current component based on the first relationship and the second relationship.

[0127] The modules in the aforementioned MMC low-voltage stability control device based on linear active disturbance rejection can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0128] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 7As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs stored in the non-volatile storage media. The database stores relevant data such as voltage outer loop parameters and current inner loop component reference data. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a low-voltage stability control method based on linear active disturbance rejection (AMC).

[0129] Those skilled in the art will understand that Figure 7 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0130] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0131] Obtain the voltage outer loop parameters in the linear active disturbance rejection model;

[0132] Based on the outer voltage loop parameters, determine the reference data for the inner current loop component of the MMC;

[0133] Based on the reference data of the inner current loop component, the steady state judgment result of MMC is determined;

[0134] When the stability assessment result indicates that the MMC is in an unstable state, stability control is performed on the MMC.

[0135] In one embodiment, the processor performs the following steps when executing a computer program:

[0136] Substituting the voltage outer loop parameters into the linear active disturbance rejection model, we obtain the reference data for the current inner loop component of the MMC.

[0137] In one embodiment, the voltage outer loop parameters include the voltage outer loop control gain and the disturbance amount; correspondingly, when the processor executes the computer program, it performs the following steps:

[0138] Determine the correspondence between DC-side voltage and current components in the MMC; based on the correspondence, determine the voltage outer loop parameters in the linear active disturbance rejection model.

[0139] In one embodiment, the processor performs the following steps when executing a computer program:

[0140] The voltage outer loop control gain is determined based on the coefficients of the current components contained in the correspondence; and the disturbance is determined based on the intercept contained in the correspondence.

[0141] In one embodiment, the voltage outer loop parameters further include a linear state error feedback output; correspondingly, the processor executes the following steps when running the computer program:

[0142] Obtain the outer voltage reference value and DC bus voltage of the MMC during operation; determine the linear state error feedback output based on the outer voltage reference value, DC bus voltage and preset error feedback proportional coefficient.

[0143] In one embodiment, the processor performs the following steps when executing a computer program:

[0144] Obtain the first relationship between the current component and the AC side power in the MMC, and the second relationship between the DC side voltage and the DC side power in the MMC; determine the correspondence between the DC side voltage and the current component based on the first and second relationships.

[0145] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0146] Obtain the voltage outer loop parameters in the linear active disturbance rejection model;

[0147] Based on the outer voltage loop parameters, determine the reference data for the inner current loop component of the MMC;

[0148] Based on the reference data of the inner current loop component, the steady state judgment result of MMC is determined;

[0149] When the stability assessment result indicates that the MMC is in an unstable state, stability control is performed on the MMC.

[0150] In one embodiment, when a computer program is executed by a processor, it performs the following steps:

[0151] Substituting the voltage outer loop parameters into the linear active disturbance rejection model, we obtain the reference data for the current inner loop component of the MMC.

[0152] In one embodiment, the voltage outer loop parameters include the voltage outer loop control gain and the disturbance amount; correspondingly, when the computer program is executed by the processor, it performs the following steps:

[0153] Determine the correspondence between DC-side voltage and current components in the MMC; based on the correspondence, determine the voltage outer loop parameters in the linear active disturbance rejection model.

[0154] In one embodiment, when a computer program is executed by a processor, it performs the following steps:

[0155] The voltage outer loop control gain is determined based on the coefficients of the current components contained in the correspondence; and the disturbance is determined based on the intercept contained in the correspondence.

[0156] In one embodiment, the voltage outer loop parameters further include a linear state error feedback output; correspondingly, when the computer program is executed by the processor, it performs the following steps:

[0157] Obtain the outer voltage reference value and DC bus voltage of the MMC during operation; determine the linear state error feedback output based on the outer voltage reference value, DC bus voltage and preset error feedback proportional coefficient.

[0158] In one embodiment, when a computer program is executed by a processor, it performs the following steps:

[0159] Obtain the first relationship between the current component and the AC side power in the MMC, and the second relationship between the DC side voltage and the DC side power in the MMC; determine the correspondence between the DC side voltage and the current component based on the first and second relationships.

[0160] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps:

[0161] Obtain the voltage outer loop parameters in the linear active disturbance rejection model;

[0162] Based on the outer voltage loop parameters, determine the reference data for the inner current loop component of the MMC;

[0163] Based on the reference data of the inner current loop component, the steady state judgment result of MMC is determined;

[0164] When the stability assessment result indicates that the MMC is in an unstable state, stability control is performed on the MMC.

[0165] In one embodiment, when a computer program is executed by a processor, it performs the following steps:

[0166] Substituting the voltage outer loop parameters into the linear active disturbance rejection model, we obtain the reference data for the current inner loop component of the MMC.

[0167] In one embodiment, the voltage outer loop parameters include the voltage outer loop control gain and the disturbance amount; correspondingly, when the computer program is executed by the processor, it performs the following steps:

[0168] Determine the correspondence between DC-side voltage and current components in the MMC; based on the correspondence, determine the voltage outer loop parameters in the linear active disturbance rejection model.

[0169] In one embodiment, when a computer program is executed by a processor, it performs the following steps:

[0170] The voltage outer loop control gain is determined based on the coefficients of the current components contained in the correspondence; and the disturbance is determined based on the intercept contained in the correspondence.

[0171] In one embodiment, the voltage outer loop parameters further include a linear state error feedback output; correspondingly, when the computer program is executed by the processor, it performs the following steps:

[0172] Obtain the outer voltage reference value and DC bus voltage of the MMC during operation; determine the linear state error feedback output based on the outer voltage reference value, DC bus voltage and preset error feedback proportional coefficient.

[0173] In one embodiment, when a computer program is executed by a processor, it performs the following steps:

[0174] Obtain the first relationship between the current component and the AC side power in the MMC, and the second relationship between the DC side voltage and the DC side power in the MMC; determine the correspondence between the DC side voltage and the current component based on the first and second relationships.

[0175] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0176] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0177] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A low-voltage stability control method for MMC based on linear active disturbance rejection, characterized in that, The method, applied to a modular multilevel converter (MMC) based on a pre-built linear active disturbance rejection model control, includes: Obtain the voltage outer loop parameters in the linear active disturbance rejection model; Based on the outer voltage loop parameters, determine the reference data for the inner current loop component of the MMC; Based on the reference data of the inner current loop component, the steady state judgment result of the MMC is determined; If the stability determination result indicates that the MMC is in an unstable state, stability control is performed on the MMC.

2. The method according to claim 1, characterized in that, The step of determining the reference data for the current inner loop component of the MMC based on the outer voltage loop parameters includes: Substituting the voltage outer loop parameters into the linear active disturbance rejection model, the reference data of the current inner loop component of the MMC is obtained.

3. The method according to claim 1, characterized in that, The voltage outer loop parameters include the voltage outer loop control gain and disturbance amount; Accordingly, obtaining the voltage outer loop parameters in the linear active disturbance rejection model includes: Determine the correspondence between the DC-side voltage and current components in the MMC; Based on the aforementioned correspondence, the voltage outer loop parameters in the linear active disturbance rejection model are determined.

4. The method according to claim 3, characterized in that, The step of determining the voltage outer loop parameters in the linear active disturbance rejection model based on the correspondence includes: The voltage outer loop control gain is determined based on the coefficients of the current component included in the aforementioned correspondence; and, The disturbance amount is determined based on the intercept contained in the correspondence.

5. The method according to claim 3 or 4, characterized in that, The voltage outer loop parameters also include the linear state error feedback output; Accordingly, obtaining the voltage outer loop parameters in the linear active disturbance rejection model includes: Obtain the outer loop voltage reference value and DC bus voltage of the MMC during operation; The linear state error feedback output is determined based on the outer voltage reference value, the DC bus voltage, and the preset error feedback ratio coefficient.

6. The method according to claim 3, characterized in that, Determining the correspondence between the DC-side voltage and current components in the MMC includes: Obtain a first relationship between the current component and the AC side power in the MMC, and a second relationship between the DC side voltage and the DC side power in the MMC; Based on the first relationship and the second relationship, the correspondence between the DC side voltage and current components is determined.

7. A low-voltage stability control device based on linear active disturbance rejection (AMC), characterized in that, The device, configured in an MMC controlled by a pre-built linear active disturbance rejection model, includes: The acquisition module is used to acquire the voltage outer loop parameters in the linear active disturbance rejection model; The first determining module is used to determine reference data for the current inner loop component based on the MMC according to the voltage outer loop parameters; The second determining module is used to determine the stability state judgment result of the MMC based on the reference data of the inner current loop component. The control module is used to perform stability control on the MMC when the stability judgment result indicates that the MMC is in an unstable state.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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