M3C bridge arm reactance optimization method, system, equipment and medium

Abstract

The invention discloses an M3C bridge arm reactance optimization method, system and device and a medium, and belongs to the technical field of power electronics, a mathematical model of a modular matrix converter M3C single bridge arm loop is established, a bridge arm voltage expression is deduced, and bridge arm voltage and bridge arm current are respectively split into a power frequency component and a low frequency component; setting a first proportion of the reactance voltage drop of the power frequency side bridge arm to the bridge arm voltage and a second proportion of the reactance voltage drop of the low frequency side bridge arm to the bridge arm voltage, wherein the first proportion is greater than the second proportion; determining a proportion relation between a power frequency component and a low frequency component in the bridge arm current; deducing the upper limit value of the reactance voltage drop of the bridge arm according to the first proportion, the second proportion and the ratio of the power frequency component to the low frequency component; and based on the upper limit value of the reactance voltage drop, combining the power frequency angular frequency, the low frequency angular frequency and the corresponding bridge arm current component, and calculating to obtain an optimized bridge arm reactance value.

Description

M3C bridge arm reactance optimization methods, systems, equipment, and media Technical Field

[0001] This invention belongs to the field of power electronics technology, specifically relating to the method, system, equipment and medium for optimizing the reactance of M3C bridge arms. Background Technology

[0002] As the core interface device between the power frequency and low frequency grids in low-frequency power transmission systems, the modular matrix converter (M3C) directly affects the system's transmission capacity, operational stability, and device lifespan through parameter design. The arm reactance, a key parameter in the M3C's main circuit, is primarily used to limit arm current, suppress circulating current, and buffer voltage fluctuations. The core of its rational design lies in precisely controlling the reactance voltage drop range—an excessively large voltage drop will result in insufficient arm voltage output, affecting the system's transmission capacity; an excessively small voltage drop will fail to effectively suppress fault current, increasing device stress.

[0003] Existing M3C arm reactor design methods largely follow the design approach of traditional modular multilevel converters (MMCs), failing to fully consider the differences in characteristics between M3C systems simultaneously connected to power frequency and low-frequency systems. On the power frequency side (e.g., 50Hz), the inductive reactance of the arm reactor is significant, and improper voltage drop control can easily limit voltage output capability. On the low-frequency side (e.g., 15~20Hz), the inductive reactance is weaker, and over-designing reactors can increase device costs and system losses. Furthermore, existing methods lack clearly defined differentiated voltage drop control strategies for the power frequency and low-frequency sides, resulting in ambiguous upper limits for reactor voltage drop. This makes it difficult to balance system stability and economy, hindering the application of M3C in high-voltage, high-capacity offshore wind power low-frequency transmission scenarios.

[0004] Therefore, there is an urgent need for a bridge arm reactance optimization design method for the dual-frequency operation characteristics of M3C (power frequency and low frequency). By accurately dividing the reactance voltage drop ratio between the power frequency side and the low frequency side, a reasonable upper limit of voltage drop can be determined, thereby optimizing the bridge arm reactance parameters and solving the defects of the existing design. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of existing M3C bridge arm reactor designs that do not distinguish between the frequency characteristics of the power frequency side and the low frequency side, resulting in unreasonable upper limit setting of reactor voltage drop, poor system operation stability, low transmission efficiency and excessive device stress. The invention proposes an optimization method, system, equipment and medium for M3C bridge arm reactors.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: Firstly, the present invention provides an M3C bridge arm reactance optimization method, comprising the following steps: establishing a mathematical model of a single bridge arm circuit of a modular matrix converter (M3C), deriving the bridge arm voltage expression, and decomposing the bridge arm voltage and bridge arm current into power frequency components and low-frequency components respectively; setting a first proportion of the power frequency side bridge arm reactance voltage drop to the bridge arm voltage, and a second proportion of the low-frequency side bridge arm reactance voltage drop to the bridge arm voltage, wherein the first proportion is greater than the second proportion; determining the proportional relationship between the power frequency component and the low-frequency component in the bridge arm current; deriving the upper limit value of the bridge arm reactance voltage drop based on the first proportion, the second proportion, and the proportion of the power frequency component and the low-frequency component; and calculating the optimized bridge arm reactance value based on the upper limit value of the reactance voltage drop, combined with the power frequency angular frequency, the low-frequency angular frequency, and the corresponding bridge arm current components.

[0007] Furthermore, the upper limit of the bridge arm reactance voltage drop is shown in the following formula:

[0008] Where L is the inductance of the bridge arm, ω1 and ω2 represent the power frequency and low-frequency angular frequency, respectively, and I arm1 I arm2 U represents the power frequency and low frequency components in the bridge arm current. v1 U v2 This represents the power frequency and low frequency components in the bridge arm voltage. This represents the peak value of the phase voltage on the power frequency side. This represents the peak value of the low-frequency side phase voltage.

[0009] Furthermore, the first proportion is 10%, and the second proportion is 5%.

[0010] Furthermore, the upper limit of the bridge arm reactance voltage drop is shown in the following formula:

[0011] Where L is the inductance of the bridge arm, ω1 and ω2 represent the power frequency and low-frequency angular frequency, respectively, and I arm1 I arm2 U represents the power frequency and low frequency components in the bridge arm current. v1 U v2 This represents the power frequency and low frequency components in the bridge arm voltage. This represents the peak value of the phase voltage on the power frequency side. This represents the peak value of the low-frequency side phase voltage.

[0012] Furthermore, the power frequency component and the low frequency component each account for 50% of the bridge arm current.

[0013] Furthermore, the upper limit of the bridge arm reactance voltage drop is shown in the following formula:

[0014] Where L is the inductance of the bridge arm, ω1 and ω2 represent the power frequency and low-frequency angular frequency, respectively, and I arm1 I arm2 U represents the power frequency and low frequency components in the bridge arm current. v1 U v2 This represents the power frequency and low frequency components in the bridge arm voltage. This represents the peak value of the phase voltage on the power frequency side. This represents the peak value of the low-frequency side phase voltage.

[0015] Furthermore, the power frequency side frequency is 50Hz, and the low frequency side frequency is 15~20Hz.

[0016] Secondly, the present invention provides an M3C bridge arm reactance optimization system, comprising: a power frequency and low frequency splitting module, used to establish a mathematical model of a single bridge arm circuit of a modular matrix converter (M3C), derive the bridge arm voltage expression, and split the bridge arm voltage and bridge arm current into power frequency components and low frequency components respectively; a voltage drop ratio setting module, used to set a first ratio of the power frequency side bridge arm reactance voltage drop to the bridge arm voltage, and a second ratio of the low frequency side bridge arm reactance voltage drop to the bridge arm voltage, wherein the first ratio is greater than the second ratio; a component ratio determination module, used to determine the ratio relationship between the power frequency component and the low frequency component in the bridge arm current; an upper limit value derivation module, used to derive the upper limit value of the bridge arm reactance voltage drop based on the first ratio, the second ratio, and the ratio of the power frequency component and the low frequency component; and an optimized reactance calculation module, used to calculate the optimized bridge arm reactance value based on the upper limit value of the reactance voltage drop, combined with the power frequency angular frequency, the low frequency angular frequency, and the corresponding bridge arm current component.

[0017] Thirdly, the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the M3C bridge arm reactance optimization method.

[0018] Fourthly, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the M3C bridge arm reactance optimization method.

[0019] Compared with existing technologies, this invention has the following beneficial technical effects: The M3C arm reactance optimization method proposed in this invention accurately determines the upper limit of arm reactance voltage drop, improving the operational stability and transmission efficiency of M3C in offshore wind power low-frequency transmission systems. This method establishes a mathematical model of a single M3C arm circuit, decomposes the power frequency and low-frequency components of the arm voltage and current, sets differentiated reactance voltage drop ratios based on the frequency characteristics differences between the power frequency and low-frequency sides, and derives the upper limit of reactance voltage drop by combining the arm current component ratio, ultimately optimizing the arm reactance parameters. This invention solves the problem of unreasonable voltage drop control caused by the failure of existing designs to distinguish between power frequency and low-frequency characteristics, effectively reducing device stress and increasing system transmission capacity, and is suitable for high-voltage, high-capacity offshore wind power low-frequency transmission scenarios. Attached Figure Description

[0020] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components of the invention.

[0021] In the accompanying drawings: Figure 1 is a flowchart of the M3C bridge arm reactance optimization method of the present invention.

[0022] Figure 2 is a simplified structural diagram of the M3C bridge arm reactance optimization system of the present invention.

[0023] Figure 3 is a schematic diagram of the electronic device for the M3C bridge arm reactance optimization method of the present invention.

[0024] Figure 4 is a schematic diagram of a typical M3C topology.

[0025] Figure 5 is a topology diagram of the M3C single-bridge arm loop in an embodiment of the present invention.

[0026] Figure 6 is a simplified three-phase circuit topology diagram of the M3C power frequency side in an embodiment of the present invention.

[0027] Figure 7 is a simplified three-phase circuit topology diagram of the low-frequency side of M3C in an embodiment of the present invention. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0029] Example 1, referring to Figure 1, describes the M3C bridge arm reactance optimization method, which includes the following steps: establishing a mathematical model of a single bridge arm circuit of the modular matrix converter M3C, deriving the bridge arm voltage expression, and decomposing the bridge arm voltage and bridge arm current into power frequency components and low frequency components, respectively; the upper limit of the bridge arm reactance voltage drop is shown in the following formula:

[0030] Where L is the inductance of the bridge arm, ω1 and ω2 represent the power frequency and low-frequency angular frequency, respectively, and I arm1 I arm2 U represents the power frequency and low frequency components in the bridge arm current. v1 U v2 This represents the power frequency and low frequency components in the bridge arm voltage. This represents the peak value of the phase voltage on the power frequency side. This represents the peak value of the low-frequency side phase voltage.

[0031] A first proportion is set for the voltage drop of the power frequency side arm reactance to the arm voltage, and a second proportion is set for the voltage drop of the low frequency side arm reactance to the arm voltage, wherein the first proportion is greater than the second proportion; the first proportion is 10%, and the second proportion is 5%.

[0032] The upper limit of the voltage drop of the bridge arm reactance is shown in the following formula:

[0033] Where L is the inductance of the bridge arm, ω1 and ω2 represent the power frequency and low-frequency angular frequency, respectively, and I arm1 I arm2 U represents the power frequency and low frequency components in the bridge arm current. v1 U v2 This represents the power frequency and low frequency components in the bridge arm voltage. This represents the peak value of the phase voltage on the power frequency side. This represents the peak value of the low-frequency side phase voltage.

[0034] The power frequency component and the low frequency component each account for 50% of the current in the bridge arm. The upper limit of the voltage drop of the bridge arm reactance is shown in the following formula:

[0035] Where L is the inductance of the bridge arm, ω1 and ω2 represent the power frequency and low-frequency angular frequency, respectively, and I arm1 I arm2 U represents the power frequency and low frequency components in the bridge arm current. v1 U v2 This represents the power frequency and low frequency components in the bridge arm voltage. This represents the peak value of the phase voltage on the power frequency side. This represents the peak value of the low-frequency side phase voltage.

[0036] The power frequency side frequency is 50Hz, and the low frequency side frequency is 15~20Hz.

[0037] Determine the ratio of power frequency component to low frequency component in the bridge arm current; derive the upper limit of bridge arm reactance voltage drop based on the first ratio, the second ratio, and the ratio of power frequency component to low frequency component; and calculate the optimized bridge arm reactance value based on the upper limit of reactance voltage drop, combined with the power frequency angular frequency, the low frequency angular frequency, and the corresponding bridge arm current component.

[0038] This invention achieves precise control of the upper limit of reactance voltage drop by separating the power frequency and low frequency components of the bridge arm voltage and current, and setting differentiated reactance voltage drop ratios for different frequency characteristics, thus avoiding system performance imbalance caused by a single ratio design. The optimized bridge arm reactance can suppress fault current and buffer voltage fluctuations while ensuring the voltage output capability of the M3C, improving the system's transmission capacity and operational stability. It reduces the current and voltage stress on the bridge arm components, extends the equipment's service life, and avoids cost waste caused by over-design, thereby improving the economic efficiency of offshore wind power low-frequency transmission systems. The method has clear logic and is easy to calculate, and can be directly applied to the engineering design of high-voltage, high-capacity M3Cs, especially suitable for offshore wind power low-frequency transmission scenarios in the 15~20Hz frequency band.

[0039] This embodiment of the M3C bridge arm reactance optimization method, by accurately separating the power frequency and low frequency components of the bridge arm voltage and current, establishes a targeted mathematical model and sets differentiated voltage drop ratios, possessing significant technical advantages and practical value. Its core benefit lies in achieving coordinated optimization control of the dual-frequency components. The voltage drop ratio setting of 10% on the power frequency side and 5% on the low frequency side not only meets the voltage stability requirements under the 50Hz power frequency condition but also adapts to the operating characteristics of the 15~20Hz low frequency band, avoiding performance redundancy or inadequacy caused by a single ratio design.

[0040] By clearly defining the proportion of current components and quantifying the upper limit of voltage drop, the derivation process is both rigorous and practical, significantly improving the accuracy of reactance parameter design and effectively reducing the trial-and-error costs associated with traditional experience-based design. The optimized bridge arm reactance value can accurately match the reactance voltage drop requirements under dual-frequency operating conditions, reducing power transmission losses, improving the energy conversion efficiency of the M3C converter, enhancing the system's operational stability over a wide frequency range, suppressing harmonic interference, and improving power quality.

[0041] Furthermore, this method requires no additional hardware modifications and achieves optimization solely through mathematical modeling and parameter derivation, balancing economic efficiency and operability. It is applicable to scenarios such as wind power and rail transit that rely on M3C converters, providing key technical support for the long-term reliable operation of equipment.

[0042] Example 2, referring to Figure 2, describes an M3C bridge arm reactance optimization system, comprising: a power frequency and low frequency splitting module for establishing a mathematical model of a single bridge arm circuit of the modular matrix converter M3C, deriving the bridge arm voltage expression, and splitting the bridge arm voltage and current into power frequency and low frequency components respectively; a voltage drop ratio setting module for setting a first ratio of the power frequency side bridge arm reactance voltage drop to the bridge arm voltage, and a second ratio of the low frequency side bridge arm reactance voltage drop to the bridge arm voltage, wherein the first ratio is greater than the second ratio; a component ratio determination module for determining the ratio relationship between the power frequency component and the low frequency component in the bridge arm current; an upper limit value derivation module for deriving the upper limit value of the bridge arm reactance voltage drop based on the first ratio, the second ratio, and the ratio of the power frequency component to the low frequency component; and an optimized reactance calculation module for calculating the optimized bridge arm reactance value based on the upper limit value of the reactance voltage drop, combined with the power frequency angular frequency, the low frequency angular frequency, and the corresponding bridge arm current component.

[0043] This embodiment of the M3C bridge arm reactance optimization system achieves scientific optimization of bridge arm reactance by precisely separating power frequency and low-frequency components and differentially setting voltage drop ratios. Its core advantage lies in breaking through the limitations of traditional "one-size-fits-all" designs. It allocates voltage drop ratios based on the frequency characteristics of voltage and current, ensuring both the accuracy of voltage drop control on the power frequency side and the operational flexibility on the low-frequency side, significantly reducing bridge arm energy consumption and heat loss. Simultaneously, by quantitatively deriving the upper limit of voltage drop and accurately calculating reactance values, it effectively improves the voltage-current matching degree of the M3C converter, reduces harmonic interference and operational fluctuations, and enhances system stability and operating efficiency. Furthermore, the optimization process is logically rigorous and highly operable, simplifying the engineering complexity of reactance design, reducing R&D and application costs, and providing key technical support for the efficient and reliable operation of modular matrix converters.

[0044] Example 3 (Referring to Figure 3) illustrates an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements an M3C bridge arm reactance optimization method: A mathematical model of a single-bridge arm circuit of the modular matrix converter (M3C) is established; the bridge arm voltage expression is derived; the bridge arm voltage and bridge arm current are decomposed into power frequency components and low-frequency components, respectively; a first proportion of the power frequency side bridge arm reactance voltage drop to the bridge arm voltage and a second proportion of the low-frequency side bridge arm reactance voltage drop to the bridge arm voltage are set, where the first proportion is greater than the second proportion; the proportional relationship between the power frequency component and the low-frequency component in the bridge arm current is determined; based on the first proportion, the second proportion, and the proportions of the power frequency component and the low-frequency component, an upper limit value of the bridge arm reactance voltage drop is derived; based on the upper limit value of the reactance voltage drop, combined with the power frequency angular frequency, the low-frequency angular frequency, and the corresponding bridge arm current components, the optimized bridge arm reactance value is calculated.

[0045] Example 4: A computer-readable storage medium storing a computer program, which, when executed by a processor, implements an M3C bridge arm reactance optimization method: A mathematical model of a single-bridge arm circuit of a modular matrix converter (M3C) is established; the bridge arm voltage expression is derived; the bridge arm voltage and current are decomposed into power frequency components and low-frequency components, respectively; a first proportion of the power frequency side bridge arm reactance voltage drop to the bridge arm voltage and a second proportion of the low-frequency side bridge arm reactance voltage drop to the bridge arm voltage are set, wherein the first proportion is greater than the second proportion; the proportional relationship between the power frequency component and the low-frequency component in the bridge arm current is determined; based on the first proportion, the second proportion, and the proportions of the power frequency component and the low-frequency component, an upper limit value of the bridge arm reactance voltage drop is derived; based on the upper limit value of the reactance voltage drop, combined with the power frequency angular frequency, the low-frequency angular frequency, and the corresponding bridge arm current components, the optimized bridge arm reactance value is calculated.

[0046] Example 5: M3C Arm Reactance Optimization Method. A typical modular multilevel matrix converter (M3C) is shown in Figure 4. The two sides of the converter can be used to connect two three-phase systems (i.e., the input side and the output side). It consists of nine arm branches, each containing several cascaded H-bridge submodules and branch inductors. The M3C has nine arms, and the submodules are full-bridge submodules. The minimum voltage of each arm is the difference between the peak AC phase voltages on both sides.

[0047] The topology of a single bridge arm of the M3C is shown in Figure 5. A single-arm loop model is established, and the voltage expression is derived. The M3C consists of nine identical bridge arm branches, each branch composed of several cascaded full-bridge submodules connected in series with the bridge arm inductor. A single bridge arm is selected as the analysis object, and a single-arm loop model is established. Based on Kirchhoff's Voltage Law (KVL), the voltage expression for the single-arm loop is derived as follows: (1) Among them, the bridge arm current consists of one-third of the power frequency side current, one-third of the low frequency side current, and circulating current. Ignoring the circulating current for now, the above formula can be rearranged into two different frequencies: (2) Separate the power frequency and low frequency in equation (2) and further extend it to a three-phase form, as shown in Figure 6. That is: (3) The current of a certain phase on the power frequency side will be shunted to the bridge arms of three different sub-converters. Each bridge arm only carries 1 / 3 of the phase current. Therefore, the actual voltage drop of the bridge arm inductance is equivalent to: × Rate of change of phase current.

[0048] The simplified three-phase circuit on the low-frequency side is shown in Figure 7. That is: (4) In the above formula (4), v u a_1 Indicates voltage v ua The power frequency component in the v u a_2 Indicates voltage v u a The low-frequency components in the data (the circulating components are omitted for ease of analysis).

[0049] According to equation (3), the voltage division of the bridge arm reactance at rated power on the power frequency side is... The voltage drop is slightly smaller than that of the reactance in a traditional MMC. Therefore, from a control perspective alone, the no-load modulation index on the power frequency side can be larger than the traditional MMC design of 0.85; we can initially take it as 0.9. Then, the power frequency voltage output capability of the bridge arm will be... , This represents the peak value of the phase voltage on the power frequency side.

[0050] According to equation (4), the voltage division of the bridge arm reactance at the rated power on the low-frequency side is... Considering that the low-frequency frequency is much lower than the power frequency, the voltage division of the bridge arm reactor is also smaller. When the frequency is one-third of the power frequency, the low-frequency voltage division amplitude of the bridge arm reactor is only one-third of that of the power frequency. Therefore, the no-load modulation index can be further increased, initially set to 0.95, meaning the low-frequency voltage output capability of the bridge arm is... , This represents the peak value of the low-frequency side phase voltage.

[0051] Therefore, the total bridge arm voltage output capability is obtained as follows: .

[0052] In the simplified circuit on the power frequency side, the design arm reactance voltage drop is 10% of the arm voltage; in the simplified circuit on the low frequency side, the design arm reactance voltage drop is 5% of the arm voltage. Therefore, the upper limit of the arm reactance voltage drop can be derived: (5) (6) Due to the I in the bridge arm current arm1 I arm2 The proportions are basically the same (assuming the transformer valve-side design voltage remains consistent), each accounting for 50%. Therefore, the above formula can be further simplified: (7) In the formula, L is the inductance of the bridge arm, ω1 and ω2 represent the power frequency and low frequency angular frequency, respectively, and I arm1 I arm2 U represents the power frequency and low frequency components in the bridge arm current. v1 U v2 This represents the power frequency and low frequency components in the bridge arm voltage. This represents the peak value of the phase voltage on the power frequency side. This represents the peak value of the low-frequency side phase voltage.

[0053] The M3C arm reactance optimization method in this embodiment offers several significant advantages. First, by designing the no-load regulation by frequency division (0.9 on the power frequency side and 0.95 on the low-frequency side), the total voltage output capacity of the arm is significantly improved, enhancing the converter's adaptability and operational flexibility to different frequency systems. Second, utilizing the characteristic that the power frequency and low-frequency components each account for 50% of the arm current, combined with the fact that the low-frequency voltage drop amplitude is only one-third of the power frequency voltage drop, the actual voltage drop requirement of the arm reactance is significantly reduced, minimizing reactive power loss. Furthermore, by setting reasonable upper limits of 10% for the power frequency side voltage drop and 5% for the low-frequency side, the inductance value can be accurately derived, avoiding over-design leading to increased size and weight, and reducing equipment costs and installation space requirements. Simultaneously, the optimized reactance parameters ensure stable operation at rated power, improving voltage output margin and ensuring system control accuracy through reasonable voltage division control, providing crucial support for the efficient and reliable operation of the M3C in three-phase systems connected at different frequencies.

[0054] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0055] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0056] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0057] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An M3C bridge arm reactance optimization method, characterized in that, The steps include: establishing a mathematical model of a single-arm circuit of a modular matrix converter M3C, deriving the expression for the arm voltage, and decomposing the arm voltage and arm current into power frequency components and low frequency components, respectively; setting a first proportion of the power frequency side arm reactance voltage drop to the arm voltage and a second proportion of the low frequency side arm reactance voltage drop to the arm voltage, wherein the first proportion is greater than the second proportion. Determine the ratio of power frequency component to low frequency component in the bridge arm current; Based on the first ratio, the second ratio, and the proportions of power frequency components and low frequency components, the upper limit of the bridge arm reactance voltage drop is derived. Based on the upper limit of the reactance voltage drop, combined with the power frequency angular frequency, low frequency angular frequency and the corresponding bridge arm current component, the optimized bridge arm reactance value is calculated.

2. The M3C bridge arm reactance optimization method according to claim 1, characterized in that, The upper limit of the voltage drop of the bridge arm reactance is shown in the following formula: Where L is the inductance of the bridge arm, ω1 and ω2 represent the power frequency and low-frequency angular frequency, respectively, and I arm1 I arm2 U represents the power frequency and low frequency components in the bridge arm current. v1 U v2 This represents the power frequency and low frequency components in the bridge arm voltage. This represents the peak value of the phase voltage on the power frequency side. This represents the peak value of the low-frequency side phase voltage.

3. The M3C bridge arm reactance optimization method according to claim 1, characterized in that, The first ratio is 10%, and the second ratio is 5%.

4. The M3C bridge arm reactance optimization method according to claim 3, characterized in that, The upper limit of the voltage drop of the bridge arm reactance is shown in the following formula: Where L is the inductance of the bridge arm, ω1 and ω2 represent the power frequency and low-frequency angular frequency, respectively, and I arm1 I arm2 U represents the power frequency and low frequency components in the bridge arm current. v1 U v2 This represents the power frequency and low frequency components in the bridge arm voltage. This represents the peak value of the phase voltage on the power frequency side. This represents the peak value of the low-frequency side phase voltage.

5. The M3C bridge arm reactance optimization method according to claim 1, characterized in that, The power frequency component and the low frequency component each account for 50% of the current in the bridge arm.

6. The M3C bridge arm reactance optimization method according to claim 5, characterized in that, The upper limit of the voltage drop of the bridge arm reactance is shown in the following formula: Where L is the inductance of the bridge arm, ω1 and ω2 represent the power frequency and low-frequency angular frequency, respectively, and I arm1 I arm2 U represents the power frequency and low frequency components in the bridge arm current. v1 U v2 This represents the power frequency and low frequency components in the bridge arm voltage. This represents the peak value of the phase voltage on the power frequency side. This represents the peak value of the low-frequency side phase voltage.

7. The M3C bridge arm reactance optimization method according to claim 1, characterized in that, The power frequency side frequency is 50Hz, and the low frequency side frequency is 15~20Hz.

8. The M3C bridge arm reactance optimization system, characterized in that, include: The power frequency and low frequency modules are separated to establish a mathematical model of the single-bridge arm circuit of the modular matrix converter M3C, derive the expression of the bridge arm voltage, and separate the bridge arm voltage and bridge arm current into power frequency components and low frequency components respectively. The voltage drop ratio setting module is used to set a first ratio of the voltage drop of the power frequency side bridge arm reactance to the bridge arm voltage, and a second ratio of the voltage drop of the low frequency side bridge arm reactance to the bridge arm voltage, wherein the first ratio is greater than the second ratio. The component proportion determination module is used to determine the proportion relationship between the power frequency component and the low frequency component in the bridge arm current; The upper limit value derivation module is used to derive the upper limit value of the bridge arm reactance voltage drop based on the first ratio, the second ratio, and the ratio of the power frequency component to the low frequency component. The optimized reactance module is used to calculate the optimized bridge arm reactance value based on the upper limit of the reactance voltage drop, combined with the power frequency angular frequency, low frequency angular frequency and the corresponding bridge arm current component.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the M3C bridge arm reactance optimization method according to any one of claims 1-7.

10. A computer-readable storage medium storing a computer program that, when executed by a processor, implements the M3C arm reactance optimization method according to any one of claims 1-7.

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