Control method and device of modular multilevel matrix converter

Abstract

The invention provides a control method and device for a modular multi-level matrix converter, and the method comprises the steps: obtaining a power tracking error of the modular multi-level matrix converter; generating a sliding mode surface according to the power tracking error; determining a smoothing factor according to the harmonic rate and the steady-state error of the output current of the modular multilevel matrix converter; determining an approaching rate according to the sliding mode surface and the smoothing factor; and forming an outer ring active power controller of the modular multi-level matrix converter through the sliding mode surface and the approaching rate so as to reduce buffeting of the modular multi-level matrix converter. By means of the scheme, the technical problems that an existing modular multilevel matrix converter is weak in robustness and large in system buffeting are solved, and the technical effect that when the modular multilevel matrix converter controls parameter changes and external disturbance modes of the system, the anti-interference capacity of the system can be improved is achieved.

Description

Technical Field

[0001] This application belongs to the technical field of circuit control, and particularly relates to a control method and device for a modular multilevel matrix converter. Background Art

[0002] A modular multilevel converter (MMC) is formed by cascading multiple sub-modules (SMs) with the same structure. The structure of the sub-module can be divided into three types: half H-bridge type, full H-bridge type, and double-clamped type sub-module type. The modular multilevel converter has shown extremely important engineering application prospects.

[0003] However, the high-voltage, large-capacity, and ultra-large-scale MMC high-efficiency modeling is restricted by many factors such as modeling methods, mathematical theories, equivalent experimental methods, and computer hardware, severely restricting the rapid development of related fields. Therefore, establishing the mathematical and simulation models of MMC can reflect the general operating laws of the converter, which has important guiding significance for studying the operating characteristics of flexible DC transmission systems, the selection of main circuit parameters, and the design of control and protection systems. Conducting research on the electromagnetic transient modeling methods of MMC at different time scales, studying the theory and methods to greatly improve the simulation efficiency of MMC while ensuring the simulation accuracy, and proposing high-efficiency simulation models of MMC applicable to different application scenarios have important theoretical and engineering significance.

[0004] Currently, the outer-loop active power controller of a modular multilevel matrix converter usually adopts PI control, but PI control is very sensitive to system parameter changes and external disturbances, which will result in weak system robustness. Further, when the modular multilevel matrix converter is used for new energy power transmission, due to the intermittency and uncertainty of new energy, the system is often disturbed, and the existing PI control is very sensitive to system parameter changes and external disturbances, resulting in weak system robustness.

[0005] Aiming at the technical problems of weak robustness and large system chattering existing in the existing modular multilevel matrix converter, no effective solution has been proposed yet. Summary of the Invention

[0006] The purpose of this application is to provide a control method and device for a modular multilevel matrix converter, which can solve the technical problems of weak robustness and large system chattering existing in the existing modular multilevel matrix converter.

[0007] The control and device provided by this application are implemented as follows:

[0008] A control method for a modular multilevel matrix converter, the method includes:

[0009] Obtain the power tracking error of the modular multilevel matrix converter;

[0010] Generate a sliding mode surface according to the power tracking error;

[0011] Determine a smoothing factor according to the harmonic rate and steady-state error of the output current of the modular multilevel matrix converter;

[0012] Determine the reaching law according to the sliding mode surface and the smoothing factor;

[0013] Form an outer-loop active power controller of the modular multilevel matrix converter through the sliding mode surface and the reaching law to reduce the chattering of the modular multilevel matrix converter.

[0014] In one embodiment, generating a sliding mode surface according to the power tracking error includes:

[0015] Form a sliding mode surface according to the following formula:

[0016] s = e + β∫|e| γ sign(e)dt

[0017] where s is the sliding mode surface, e is the power tracking error, e = P ref - P, P ref is the reference power, P is the actually measured power, β represents the sliding mode coefficient, γ represents the non-linear weight, 0 < γ < 1, and t represents time.

[0018] In one embodiment, determining the reaching law according to the sliding mode surface and the smoothing factor includes:

[0019] Calculate the reaching law according to the following formula:

[0020]

[0021] where represents the reaching law, δ and ε represent the smoothing factors, k 1 and k 2 represent the adaptive gains, k 1 = β||e||, k 2 = β(1 - e -λ|s| )), tanh() represents the hyperbolic tangent function, s is the sliding mode surface, and β represents the sliding mode coefficient.

[0022] In one embodiment, determining the smoothing factor according to the harmonic rate and steady-state error of the output current of the modular multilevel matrix converter includes:

[0023] Input the relevant parameters of the particle swarm, where the relevant parameters include at least one of the following: the number of particle populations, the number of iterations, the particle transformation speed, the number of independent variables, and the number of iterations;

[0024] Randomly generate an initial particle swarm, where one particle corresponds to one solution, and one solution corresponds to a set of smoothing factors;

[0025] Iterate the particle swarm for the number of iterations according to the particle transformation speed to obtain multiple particle swarms;

[0026] Calculate the fitness of each particle in the multiple particle swarms through a preset fitness formula;

[0027] Select the particle with the highest fitness as the target particle;

[0028] Take the set of smoothing factors corresponding to the target particle as the determined smoothing factors.

[0029] In one embodiment, calculating the fitness of each particle in the multiple particle swarms through a preset fitness formula includes:

[0030] Calculate the fitness of the current particle according to the following formula:

[0031] P = τL + υE

[0032] where P represents the fitness of the current particle, τ and υ represent constants greater than zero, L represents the harmonic rate of the converter output current corresponding to the current particle, and E represents the steady-state error corresponding to the current particle.

[0033] A control device for a modular multilevel matrix converter, the device includes:

[0034] An acquisition module for acquiring the power tracking error of the modular multilevel matrix converter;

[0035] A generation module for generating a sliding mode surface according to the power tracking error;

[0036] A first determination module for determining a smoothing factor according to the harmonic rate and steady-state error of the output current of the modular multilevel matrix converter;

[0037] A second determination module for determining an approach rate according to the sliding mode surface and the smoothing factor;

[0038] A control module for forming an outer-loop active power controller of the modular multilevel matrix converter through the sliding mode surface and the approach rate to reduce the chattering of the modular multilevel matrix converter.

[0039] In one embodiment, the second determination module is used to calculate the approach rate according to the following formula:

[0040]

[0041] Among them, represents the approaching rate, δ and ε represent smoothing factors, and k 1 and k 2 represent adaptive gains, and k 1 =β||e||, k 2 =β(1 - e -λ|s| ), tanh() represents the hyperbolic tangent function, s is the sliding mode surface, and β represents the sliding mode coefficient.

[0042] An electronic device includes a processor and a memory for storing processor-executable instructions. When the processor executes the instructions, the steps of the above method are implemented.

[0043] A computer-readable storage medium stores computer programs / instructions, and when the computer programs / instructions are executed by a processor, the steps of the above method are implemented.

[0044] A computer program product includes computer programs / instructions, and when the computer programs / instructions are executed by a processor, the steps of the above method are implemented.

[0045] The control method and device of the modular multilevel matrix converter provided by this application generate a sliding mode surface through the power tracking error of the modular multilevel matrix converter; and determine the smoothing factor according to the harmonic rate and steady-state error of the output current of the modular multilevel matrix converter; further, determine the approaching rate according to the sliding mode surface and the smoothing factor; form an outer-loop active power controller of the modular multilevel matrix converter through the sliding mode surface and the approaching rate to reduce the chattering of the modular multilevel matrix converter. Through the above solution, the technical problems of weak robustness and large system chattering existing in the existing modular multilevel matrix converter are solved, and the technical effect of increasing the anti-interference ability of the system can be achieved when the parameters of the modular multilevel matrix converter control system change and the external disturbance mode changes. Description of the Drawings

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0047] Figure 1 It is a flowchart of a method of an embodiment of the control method of the modular multilevel matrix converter provided by this application;

[0048] Figure 2 is the flowchart of the method for determining the smoothing factor provided by this application;

[0049] Figure 3 is the schematic diagram of the active power adopting a sliding-mode active power controller provided by this application;

[0050] Figure 4 is the hardware structure block diagram of an electronic device for the control method of a modular multilevel matrix converter provided by this application;

[0051] Figure 5 is the schematic diagram of the module structure of an embodiment of the control device of the modular multilevel matrix converter provided by this application. Detailed implementation manners

[0052] In order to enable those skilled in the art to better understand the technical solutions in this application, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0053] Figure 1 is the flowchart of the method of an embodiment of the control method of the modular multilevel matrix converter provided by this application. Although this application provides method operation steps or device structures as shown in the following embodiments or drawings, more or fewer operation steps or module units may be included in the method or device based on routine or non-creative labor. In steps or structures where there is no necessary causal relationship logically, the execution order of these steps or the module structure of the device is not limited to the execution order or module structure described in the embodiments of this application and shown in the drawings. When the method or module structure is applied to an actual device or terminal product, it can be executed sequentially or in parallel according to the method or module structure connection shown in the embodiments or drawings (for example, in a parallel processor or multi-threaded processing environment, or even a distributed processing environment).

[0054] Specifically, as Figure 1 shown, the above control method of the modular multilevel matrix converter may include the following steps 101 to 105:

[0055] Step 101: Obtain the power tracking error of the modular multilevel matrix converter;

[0056] Step 102: Generate a sliding mode surface according to the power tracking error;

[0057] For example, when implementing, the sliding surface can be formed according to the following formula:

[0058] s = e + β∫|e| γ sign(e)dt

[0059] where s is the sliding surface, e is the power tracking error, e = P ref -P, P ref is the reference power, P is the actual measured power, β represents the sliding mode coefficient, γ represents the non - linear weight, 0 < γ < 1, and t represents time.

[0060] Specifically, in the above design, a fractional - order integral term is introduced into the sliding surface, so as to achieve fast convergence when far from the equilibrium point and suppress chattering when approaching the equilibrium point.

[0061] Furthermore, by introducing the non - linear weight, the switching frequency of the sliding - mode control can be reduced. For example, when the non - linear weight approaches 0, the sliding surface approaches the linear integral form, and high - frequency chattering can be significantly reduced; when the non - linear weight approaches 1, the convergence speed is faster, and it can cooperate with the adaptive gain strategy to suppress chattering.

[0062] Step 103: Determine the smoothing factor according to the harmonic rate and steady - state error of the output current of the modular multilevel matrix converter;

[0063] Step 104: Determine the reaching law according to the sliding surface and the smoothing factor;

[0064] Step 105: Form an outer - loop active - power controller of the modular multilevel matrix converter through the sliding surface and the reaching law to reduce the chattering of the modular multilevel matrix converter.

[0065] When implementing, the reaching law can be calculated according to the following formula:

[0066]

[0067] where represents the reaching law, δ and ε represent the smoothing factors, k 1 and k 2 represent the adaptive gains, k 1 = β||e||, k 2 = β(1 - e -λ|s| ), tanh() represents the hyperbolic tangent function, s is the sliding surface, and β represents the sliding - mode coefficient.

[0068] Because the smoothing factor is used when calculating the reaching law, choosing an appropriate smoothing factor can make the result of the reaching law better suppress chattering. For this reason, in this example, a method for determining the smoothing factor is provided, which can be asFigure 2 As shown, it includes steps 201 to 206:

[0069] Step 201: Input the relevant parameters of the particle swarm. Among them, the relevant parameters include at least one of the following: the number of particle populations, the number of iterations, the particle transformation speed, the number of independent variables, and the number of iterations;

[0070] Step 202: Randomly generate the initial particle swarm. Among them, one particle corresponds to one solution, and one solution corresponds to a set of smoothing factors;

[0071] Step 203: Iterate the particle swarm for the number of iterations according to the particle transformation speed to obtain multiple particle swarms;

[0072] Step 204: Calculate the fitness of each particle in the multiple particle swarms through a preset fitness formula;

[0073] Among them, the fitness formula is expressed as:

[0074] P = τL + υE

[0075] Among them, P represents the fitness of the current particle, τ and υ represent constants greater than zero, L represents the harmonic rate of the converter output current corresponding to the current particle, and E represents the steady-state error corresponding to the current particle.

[0076] Step 205: Select the particle with the highest fitness as the target particle;

[0077] Step 206: Use the set of smoothing factors corresponding to the target particle as the determined smoothing factors.

[0078] The above method will be described below in conjunction with a specific embodiment. However, it should be noted that this specific embodiment is only for better explaining the present application and does not constitute an improper limitation of the present application.

[0079] In this example, a sliding mode outer loop active power controller is provided, which improves the reliability of the modular multilevel matrix converter control system while reducing the sliding mode chattering. That is, a new sliding mode reaching law is proposed, and a sliding mode outer loop active power controller is designed based on the newly designed sliding mode reaching law, which can improve the reliability of the modular multilevel matrix converter control system without increasing the production cost.

[0080] Specifically, in this example, a new sliding mode surface and reaching law are provided to reduce chattering:

[0081] The sliding mode surface is expressed as:

[0082] s = e + β∫|e| γ sign(e)dt

[0083] Among them, s is the sliding surface, e is the power tracking error, and e = P ref - P, where P ref is the reference power, P is the actual measured power, β represents the sliding mode coefficient, γ represents the non - linear weight, 0 < γ < 1, and t represents time.

[0084] Specifically, a fractional - order integral term is introduced in the design of this sliding surface, so as to achieve fast convergence when far from the equilibrium point and suppress chattering when approaching the equilibrium point.

[0085] The reaching law is expressed as:

[0086]

[0087] Among them, represents the reaching law, δ and ε represent the smoothing factors, k 1 and k 2 represent the adaptive gains, k 1 = β||e||, k 2 = β(1 - e -λ|s| ), and tanh() represents the hyperbolic tangent function.

[0088] For the reaching law, by designing the adaptive gain to be dynamically adjusted with the error, it not only ensures fast convergence under large errors but also reduces the switching gain to suppress chattering under small errors.

[0089] Furthermore, in the process of determining the sliding surface and the reaching law, the magnitudes of the smoothing factors δ and ε can determine the chattering situation of the output current of the modular multilevel matrix converter. When the δ and ε parameters are large, the chattering phenomenon will intensify, resulting in a large harmonic rate of the converter output current; when the δ and ε parameters are small, the speed of the system state approaching the sliding mode surface will slow down and the steady - state error will increase.

[0090] In order to obtain appropriate δ and ε, a method for solving δ and ε is given in this example. First, regard δ and ε as a two - dimensional particle, and a fitness calculation formula is provided in this example:

[0091] P = τL+υE

[0092] Among them, P represents the fitness, τ and υ represent constants greater than zero, L represents the harmonic rate of the converter output current, and E represents the steady - state error.

[0093] Based on this, a method for determining δ and ε is provided, which can include the following steps:

[0094] S1: Input the relevant parameters of the particle swarm. Among them, the relevant parameters can include: the number of particle populations, the number of iterations, the speed range, the number of independent variables, and the number of iterations, etc.;

[0095] S2: Randomly create a population, where the population refers to a set of multiple initially given solutions. Each particle represents a solution, and each solution corresponds to a set of δ and ε, forming a two-dimensional column vector matrix;

[0096] S3: Calculate the fitness of each particle according to the above fitness calculation formula. Through the fitness of each particle above, find the individual extreme value and the global extreme value;

[0097] S4: Iteratively update the particles and particle velocities;

[0098] S5: Calculate the fitness of each updated particle according to the above fitness calculation formula, and update the individual extreme value and the global extreme value of the updated particles;

[0099] S6: Determine whether the iteration times are reached. If not, repeat the above steps S4 and S5;

[0100] S7: After the iteration ends, select the particle corresponding to the global extreme value as the best particle to obtain the best δ and ε.

[0101] As Figure 3 shown, it is a schematic diagram of the active power using a sliding mode active power controller provided in this example. After using the sliding mode active power controller provided in this example, when the parameters of the modular multilevel matrix converter control system change and the external disturbance mode changes, the anti-interference ability of the system can be increased.

[0102] The method embodiments provided in the above embodiments of the present application can be executed on a mobile terminal, a computer terminal, or a similar computing device. Taking running on an electronic device as an example, Figure 4 is a hardware structure block diagram of an electronic device for a control method of a modular multilevel matrix converter provided by the present application. As Figure 4 shown, the electronic device 10 may include one or more (only one is shown in the figure) processors 02 (the processor 02 may include, but is not limited to, a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory 04 for storing data, and a transmission module 06 for communication functions. Those of ordinary skill in the art can understand that, Figure 4 the structure shown is only schematic, and it does not limit the structure of the above electronic device. For example, the electronic device 10 may further include more or fewer components than Figure 4 shown, or have a different configuration from Figure 4 shown.

[0103] The memory 04 can be used to store software programs and modules of application software, such as the program instructions / modules corresponding to the control method of the modular multilevel matrix converter in the embodiments of the present application. The processor 02 executes various functional applications and data processing by running the software programs and modules stored in the memory 04, that is, realizes the control method of the modular multilevel matrix converter of the above application program. The memory 04 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memories. In some instances, the memory 04 may further include a memory remotely provided with respect to the processor 02, and these remote memories may be connected to the electronic device 10 through a network. Examples of the above networks include but are not limited to the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0104] The transmission module 06 is used to receive or send data via a network. Specific examples of the above network may include the wireless network provided by the communication provider of the electronic device 10. In one instance, the transmission module 06 includes a network adapter (Network Interface Controller, NIC), which can be connected to other network devices through a base station and thus can communicate with the Internet. In one instance, the transmission module 06 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0105] At the software level, the control device of the above modular multilevel matrix converter can be as Figure 5 shown, including:

[0106] An acquisition module 501, configured to acquire the power tracking error of the modular multilevel matrix converter;

[0107] A generation module 502, configured to generate a sliding mode surface according to the power tracking error;

[0108] A first determination module 503, configured to determine a smoothing factor according to the harmonic rate and steady-state error of the output current of the modular multilevel matrix converter;

[0109] A second determination module 504, configured to determine an approach rate according to the sliding mode surface and the smoothing factor;

[0110] A control module 505, configured to form an outer-loop active power controller of the modular multilevel matrix converter through the sliding mode surface and the approach rate to reduce the chattering of the modular multilevel matrix converter.

[0111] In one embodiment, the second determination module 504 is configured to calculate the approach rate according to the following formula:

[0112]

[0113] Among them, represents the approach rate, δ and ε represent smoothing factors, k 1 and k 2 represent the adaptive gain, k 1 =β||e||, k 2 =β(1 - e -λ|s| ), tanh() represents the hyperbolic tangent function, s is the sliding mode surface, and β represents the sliding mode coefficient.

[0114] In one embodiment, the first determination module 503 is configured to input particle swarm related parameters, where the related parameters include at least one of the following: the number of particle populations, the number of iterations, the particle transformation speed, the number of independent variables, and the number of iterations; randomly generate an initial particle swarm, where one particle corresponds to one solution, and one solution corresponds to a set of smoothing factors; iterate the particle swarm for the number of iterations according to the particle transformation speed to obtain multiple particle swarms; calculate the fitness of each particle in the multiple particle swarms through a preset fitness formula; select the particle with the highest fitness as the target particle; and use the set of smoothing factors corresponding to the target particle as the determined smoothing factors.

[0115] In one embodiment, the first determination module 503 is configured to calculate the fitness of the current particle according to the following formula:

[0116] P = τL + υE

[0117] where P represents the fitness of the current particle, τ and υ represent constants greater than zero, L represents the harmonic rate of the converter output current corresponding to the current particle, and E represents the steady-state error corresponding to the current particle.

[0118] In one embodiment, the generation module 502 is configured to form the sliding mode surface according to the following formula:

[0119] s = e + β∫|e| γ sign(e)dt

[0120] where s is the sliding mode surface, e is the power tracking error, e = P ref -P, P ref is the reference power, P is the actual measured power, β represents the sliding mode coefficient, γ represents the non-linear weight, 0 < γ < 1, and t represents time.

[0121] Embodiments of the present application also provide a specific implementation manner of an electronic device that can implement all steps in the control method of the modular multilevel matrix converter in the above embodiments. The electronic device specifically includes the following: a processor, a memory, a communication interface, and a bus; wherein, the processor, the memory, and the communication interface complete communication with each other through the bus; the processor is used to call the computer program in the memory, and when the processor executes the computer program, all steps in the control method of the modular multilevel matrix converter in the above embodiments are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0122] Step 1: Obtain the power tracking error of the modular multilevel matrix converter;

[0123] Step 2: Generate a sliding mode surface according to the power tracking error;

[0124] Step 3: Determine a smoothing factor according to the harmonic rate and steady-state error of the output current of the modular multilevel matrix converter;

[0125] Step 4: Determine the reaching law according to the sliding mode surface and the smoothing factor;

[0126] Step 5: Form an outer-loop active power controller of the modular multilevel matrix converter through the sliding mode surface and the reaching law to reduce the chattering of the modular multilevel matrix converter.

[0127] Embodiments of the present application also provide a computer-readable storage medium that can implement all steps in the control method of the modular multilevel matrix converter in the above embodiments. A computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, all steps in the control method of the modular multilevel matrix converter in the above embodiments are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0128] Step 1: Obtain the power tracking error of the modular multilevel matrix converter;

[0129] Step 2: Generate a sliding mode surface according to the power tracking error;

[0130] Step 3: Determine a smoothing factor according to the harmonic rate and steady-state error of the output current of the modular multilevel matrix converter;

[0131] Step 4: Determine the reaching law according to the sliding mode surface and the smoothing factor;

[0132] Step 5: Form an outer-loop active power controller of the modular multilevel matrix converter through the sliding mode surface and the reaching rate to reduce the chattering of the modular multilevel matrix converter.

[0133] As can be seen from the above description, in the embodiment of the present application, a sliding mode surface is generated through the power tracking error of the modular multilevel matrix converter; and the smoothing factor is determined according to the harmonic rate and the steady-state error of the output current of the modular multilevel matrix converter; further, the reaching rate is determined according to the sliding mode surface and the smoothing factor; an outer-loop active power controller of the modular multilevel matrix converter is formed through the sliding mode surface and the reaching rate to reduce the chattering of the modular multilevel matrix converter. Through the above solution, the technical problems of the existing modular multilevel matrix converter, such as weak robustness and large system chattering, are solved, and the technical effect of increasing the anti-interference ability of the system can be achieved when the parameters of the modular multilevel matrix converter control system change and the external disturbance mode changes.

[0134] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the hardware + program type embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0135] The specific embodiments of this specification are described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the embodiments and still achieve the desired results. Additionally, the processes depicted in the figures do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0136] Although the present application provides method operation steps as described in the embodiments or flowcharts, based on routine or non-creative labor, there may be more or fewer operation steps. The step order listed in the embodiments is only one way among many step execution orders and does not represent the only execution order. When the actual device or client product is executed, it can be executed in the order shown in the embodiments or the figures or in parallel (for example, in an environment of parallel processors or multi-threaded processing).

[0137] For the convenience of description, when describing the above device, it is divided into various modules according to functions for separate description. Of course, when implementing the embodiments of this specification, the functions of each module can be implemented in the same or multiple software and / or hardware, or the modules implementing the same function can be realized by a combination of multiple sub-modules or sub-units, etc. The device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces, and the indirect coupling or communication connection of the device or unit can be in electrical, mechanical or other forms.

[0138] Those skilled in the art also know that in addition to implementing the controller in the form of pure computer-readable program code, the method steps can be logically programmed to enable the controller to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, embedded microcontrollers, etc. to achieve the same function. Therefore, such a controller can be regarded as a hardware component, and the devices included therein for implementing various functions can also be regarded as the structures within the hardware component. Or even, the devices for implementing various functions can be regarded as either software modules for implementing the method or the structures within the hardware component.

[0139] The embodiments of this specification can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The embodiments of this specification can also be practiced in a distributed computing environment, where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0140] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other, and the key point of each embodiment is to illustrate the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for the relevant parts, reference can be made to the description of the method embodiment. In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of this specification. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0141] The above description is only for the embodiments of this specification and does not limit the embodiments of this specification. For those skilled in the art, various changes and modifications can be made to the embodiments of this specification. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of this specification shall be included within the scope of the claims of the embodiments of this specification.

Claims

1. A control method for a modular multi-level matrix converter, characterized in that: The method comprises: Obtaining the power tracking error of a modular multilevel matrix converter; generating a sliding film surface according to the power tracking error; Determine a smoothing factor according to the harmonic rate and steady-state error of the output current of the modular multi-level matrix converter; Determining a convergence rate according to the synovial surface and the smoothing factor; An outer loop active power controller of a modular multi-level matrix converter is formed by means of the sliding film surface and the approach rate, so as to reduce the chattering of the modular multi-level matrix converter.

2. The method according to claim 1, characterized in that Determining a convergence rate according to the synovial surface and the smoothing factor includes: The approach rate is calculated according to the following formula: in, represents the approach rate, δ and ε represent the smoothing factors, k1 and k2 represent the adaptive gain, k1 = β||e||, k2 = β(1-e -λ|s| ), tanh() represents the hyperbolic tangent function, s is the synovial surface, and β represents the synovial coefficient.

3. The method according to claim 1, characterized in that According to the harmonic rate and steady-state error of the output current of the modular multilevel matrix converter, a smoothing factor is determined, including: Inputting particle swarm related parameters, wherein the related parameters include at least one of the following: particle population size, number of iterations, particle transformation speed, number of independent variables, and number of iterations; Randomly generate an initial particle swarm, where one particle corresponds to one solution, and one solution corresponds to a set of smoothing factors; According to the particle transformation speed, the particle swarm is iterated for the number of iterations to obtain multiple particle swarms; Calculating the fitness of each particle in the plurality of particle groups by using a preset fitness formula; Select the particle with the highest fitness as the target particle; A set of smoothing factors corresponding to the target particles is used as the determined smoothing factors.

4. The method according to claim 3, characterized in that The fitness of each particle in the plurality of particle groups is calculated by a preset fitness formula, including: The fitness of the current particle is calculated according to the following formula: P=τL+υE Wherein, P represents the fitness of the current particle, τ and υ represent constants greater than zero, L represents the harmonic rate of the converter output current corresponding to the current particle, and E represents the steady-state error corresponding to the current particle.

5. The method according to claim 1, characterized in that Generating a sliding film surface according to the power tracking error includes: The synovial surface is formed according to the following formula: Where s is the sliding surface, e is the power tracking error, e = P ref -P,P ref is the reference power, P is the actual measured power, β is the synovial coefficient, γ is the nonlinear weight, 0<γ<1, and t is the time.

6. A control device for a modular multi-level matrix converter, characterized in that: include: An acquisition module, used for acquiring a power tracking error of a modular multi-level matrix converter; A generating module, used for generating a sliding membrane surface according to the power tracking error; A first determination module is used to determine a smoothing factor according to a harmonic rate and a steady-state error of an output current of the modular multi-level matrix converter; A second determination module, configured to determine a convergence rate according to the synovial surface and the smoothing factor; The control module is used to form an outer loop active power controller of the modular multi-level matrix converter through the sliding film surface and the approach rate, so as to reduce the chattering of the modular multi-level matrix converter.

7. The device according to claim 6, characterized in that The second determination module is used to calculate the approach rate according to the following formula: in, represents the approach rate, δ and ε represent the smoothing factors, k1 and k2 represent the adaptive gain, k1 = β||e||, k2 = β(1-e -λ|s| ), tanh() represents the hyperbolic tangent function, s is the synovial surface, and β represents the synovial coefficient.

8. An electronic device comprising a processor and a memory for storing instructions executable by the processor, characterized in that: When the processor executes the instructions, the steps of the method according to any one of claims 1 to 5 are implemented.

9. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

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