H-bridge cascaded energy storage power conversion system and parameter optimization method and device thereof

Abstract

Embodiments of the present application provide an H-bridge chain energy storage power conversion system, a parameter optimization method and device thereof, and a machine readable storage medium. The method comprises: determining a key parameter design optimization objective function; according to the key parameter design optimization objective function, taking the minimum total cost of materials and the optimal output current waveform quality of the H-bridge chain energy storage power conversion system as the target, the number N of power modules is valued; the determined N value is substituted into the key parameter design optimization objective function, and the rated parameter grade, manufacturing process and cost factors of the actual product of the component are combined to determine other parameters of the component. Through the above technical solution, the total cost of materials and the optimal output voltage quality of the energy storage power conversion system are obtained, and other parameters can meet the system operation requirements.

Description

Technical Field

[0001] This invention relates to the field of parameter design technology for energy storage battery power conversion systems, specifically to a method, apparatus, and machine-readable storage medium for optimizing the parameters of an H-bridge chain energy storage power conversion system. Background Technology

[0002] As conventional fossil fuels gradually deplete, renewable energy generation will become the main form of electricity supply in the future. However, renewable energy generation systems suffer from random fluctuations, making it difficult to guarantee the stability of the output power. Therefore, energy storage systems, through power conversion devices, are needed to perform grid stability control. Thus, the power conversion system of energy storage batteries is a key technology that urgently needs to be addressed now and for a considerable period to come.

[0003] For high-voltage distribution or transmission networks of 10kV and above, there are different topologies for energy storage systems, among which the most typical and applicable topology is the H-bridge chain energy storage power conversion system. Currently, there are many design methods for H-bridge chain energy storage power conversion systems, but there are few techniques for optimizing their parameters, especially parameter design methods that comprehensively consider multiple optimization objectives. Summary of the Invention

[0004] The purpose of this invention is to provide a method, apparatus, and machine-readable storage medium for an H-bridge chain energy storage power conversion system and its parameter optimization.

[0005] To achieve the above objectives, a first aspect of the present invention provides a parameter optimization method for an H-bridge chain energy storage power conversion system, the parameter optimization method comprising:

[0006] Determine the objective function for designing and optimizing the key parameters of the H-bridge chain energy storage power conversion system;

[0007] Based on the key parameters, an optimization objective function is designed. With the goal of minimizing the total material cost and optimizing the output current waveform quality of the H-bridge chain energy storage power conversion system, the number N of power modules in the single-phase H-bridge chain power conversion circuit of the H-bridge chain energy storage power conversion system is selected.

[0008] Substitute the determined N value into the key parameter design optimization objective function, and combine it with the actual rated parameter level, manufacturing process, and cost factors of the component to determine other parameters of the component. These other parameters include at least the DC side rated voltage U of the power module. dc The inductance value L of the AC side filter inductor, the capacitance value C of the electrolytic capacitor, and the capacity Q of a single energy storage battery module. nom The number of energy storage battery modules connected in series in each parallel branch of the energy storage battery module, n Hm The rated voltage U of a single IGBTIGBT .

[0009] In this embodiment of the invention, the H-bridge chain energy storage power conversion system includes multiple single-phase H-bridge chain power conversion circuits. Each single-phase H-bridge chain power conversion circuit includes N power modules, N DC-side electrolytic capacitors, N energy storage battery modules, and an AC-side filter inductor. Each energy storage battery module includes at least one parallel branch, and each parallel branch includes multiple energy storage battery modules connected in series. The N power modules are connected in series and connected to the power grid through the AC-side filter inductor. Each battery module in the N battery modules is electrically connected to the DC side of the corresponding power module in the N power modules. Each electrolytic capacitor in the N DC-side electrolytic capacitors is connected in parallel to the DC side of the corresponding power module in the N power modules. Each power module includes a bridge circuit composed of multiple IGBTs.

[0010] In this embodiment of the invention, the objective function for optimizing the key parameters is defined as:

[0011]

[0012] Among them, S SUM U is the total material cost of the H-bridge chain energy storage power conversion system, N is the number of power modules in the single-phase H-bridge chain power conversion circuit, and U is the total material cost of the H-bridge chain energy storage power conversion system. T_ac I is the AC bus voltage of the H-bridge chain energy storage power conversion system. ac ω is the single-phase output current of the energy storage power conversion system, ω is the rated angular frequency of the grid voltage, f1 is the AC bus voltage frequency, and f s U is the switching frequency of the IGBT. IGBT The rated voltage of a single IGBT is given by L, the inductance of the AC side filter inductor is given by C, and the capacitance of the electrolytic capacitor is given by Q. nom For the capacity of a single energy storage battery module (Ah), W T_nom The total capacity of the energy storage battery system is given by δ, the maximum depth of discharge of the energy storage battery module is given by σ, and the maximum voltage fluctuation rate of the grid is given by E. nom I is the rated voltage of the energy storage battery module in the energy storage battery module. nom n is the rated current value of the H-bridge chain energy storage power conversion system. Hz V represents the number of parallel branches in a single energy storage battery module. snom n is the effective value of the rated phase voltage of the power grid. Hm M represents the number of energy storage battery modules connected in series in each parallel branch of the energy storage battery module. k1, k2, k3, and k4 are coefficients. When the power module is an H-bridge converter structure, M = 4. When the power module is an H-half-bridge converter structure, M = 2.

[0013] In this embodiment of the invention, the method for determining the values ​​of the other parameters includes:

[0014] The objective function for designing and optimizing the key parameters must satisfy the equations or inequalities.

[0015] Meets the actual product's rated parameter level and processing technology;

[0016] The value is taken within 10% of the limit value of the inequality in the objective function for key parameter design optimization.

[0017] In this embodiment of the invention, the value of N satisfies the following principle:

[0018] The value of N makes U dc The minimum value satisfies the IGBT rated voltage safety factor and cost factor;

[0019] Within the range of costs, N takes the maximum value;

[0020] N takes an even number.

[0021] In this embodiment of the invention, the safety factor and cost factor of the IGBT rated voltage are 12 and 12.5, respectively.

[0022] In this embodiment of the invention, the objective function for determining the key parameters of the H-bridge chain energy storage power conversion system includes:

[0023] Determine the AC bus voltage U of the H-bridge chain energy storage power conversion system. T_ac Rated capacity P t The number of parallel branches in a single energy storage battery module, n Hz Power module structure type, number of IGBTs M in a single power module, AC bus voltage frequency f1, and IGBT switching frequency f s And the rated voltage U of the selected electrolytic capacitor. DC_N ;

[0024] The rated capacity P t AC bus voltage U T_ac and rated voltage U DC_N Substitute into the following formula to calculate the rated voltage U of a single IGBT. IGBT and current I IGBT The rated voltage U of an electrolytic capacitor c_N and the rated current I of the AC side filter inductor. L :

[0025]

[0026] Based on the calculated IGBT current I IGBTSelect the current rating of the chosen IGBT product and choose the appropriate current rating (I). IGBT The final value;

[0027] The relationship between the unit cost of IGBT and its rated voltage, the relationship between the unit cost of electrolytic capacitor and its rated capacitance, and the relationship between the AC side filter inductor and its rated inductance were determined. The unit cost function expression of each component was obtained through data fitting.

[0028] Based on the unit cost function expressions for each component, the first relationship between the unit cost of IGBTs, electrolytic capacitors, and AC-side filter inductors and the number of power modules N in a single-phase H-bridge power conversion circuit is determined:

[0029]

[0030] Among them, S IGBT S represents the unit cost of an IGBT. C S represents the unit cost of the DC-side electrolytic capacitor. L The unit cost of the AC-side filter inductor;

[0031] Based on the first relationship, the formula for calculating the total material cost of the H-bridge chain energy storage power conversion system is determined as follows:

[0032]

[0033] Based on the total material cost calculation formula and known design parameters, determine the key parameter design optimization objective function for the H-bridge chain energy storage power conversion system.

[0034] In this embodiment of the invention, the value of δ ranges from 0.5 to 0.8.

[0035] In this embodiment of the invention, the value of σ ranges from 0.05 to 0.1.

[0036] A second aspect of the present invention provides an H-bridge chain energy storage power conversion system manufactured using the above-described parameter optimization method for H-bridge chain energy storage power conversion systems.

[0037] A third aspect of the present invention provides a processor configured to execute the parameter optimization method described above for an H-bridge chain energy storage power conversion system.

[0038] A fourth aspect of the present invention provides a parameter optimization device for an H-bridge chain energy storage power conversion system, comprising:

[0039] The objective function determination module is configured to determine the key parameter design optimization objective function of the H-bridge chain energy storage power conversion system.

[0040] The value selection module is configured to design and optimize the objective function based on the key parameters, with the goal of minimizing the total material cost and optimizing the output current waveform quality of the H-bridge chain energy storage power conversion system, and to select the value of the number N of power modules in the single-phase H-bridge chain power conversion circuit of the H-bridge chain energy storage power conversion system.

[0041] The parameter determination module is configured to substitute the determined N value into the key parameter design optimization objective function, and, in conjunction with the actual product's rated parameter level, manufacturing process, and cost factors, determine other parameters of the component. These other parameters include at least the DC-side rated voltage U of the power module. dc The inductance value L of the AC side filter inductor, the capacitance value C of the electrolytic capacitor, and the capacity Q of a single energy storage battery module. nom The number of energy storage battery modules connected in series in each parallel branch of the energy storage battery module, n Hm The rated voltage U of a single IGBT IGBT .

[0042] The fifth aspect of the present invention provides a machine-readable storage medium storing instructions that, when executed by a processor, cause the processor to implement the above-described parameter optimization method for an H-bridge chain energy storage power conversion system.

[0043] The above technical solution optimizes the total material cost and output voltage quality of the energy storage power conversion system, while ensuring that other parameters meet the system operation requirements.

[0044] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0045] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0046] Figure 1 The schematic diagram illustrates the topology of a star-connected high-voltage direct-connected three-phase H-bridge chain energy storage power conversion system according to an embodiment of the present invention.

[0047] Figure 2 Schematic illustration Figure 1 The schematic diagram of the single-phase H-bridge chain energy storage power conversion circuit in the three-phase H-bridge chain energy storage power conversion system.

[0048] Figure 3 An example flowchart illustrating the key parameter optimization design method for an H-bridge chain energy storage power conversion system according to an embodiment of the present invention is shown. Detailed Implementation

[0049] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0050] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0051] If the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0052] Figure 1 The schematic diagram illustrates the topology of a star-connected high-voltage direct-connected three-phase H-bridge chain energy storage power conversion system according to an embodiment of the present invention. Figure 1 As shown, this embodiment of the invention uses a three-phase H-bridge chain-type energy storage power conversion system (hereinafter referred to as a power conversion system or PCS system (power conversion system, energy storage converter)) as an example to illustrate the concept of the invention. This energy storage power conversion system may include multiple (for a three-phase circuit, for example, three) single-phase H-bridge chain-type power conversion circuits. Figure 2 Schematic illustration Figure 1 The schematic diagram of a single-phase H-bridge chain energy storage power conversion circuit in a three-phase H-bridge chain energy storage power conversion system. (See diagram for example.) Figure 2As shown, each single-phase H-bridge chain power conversion circuit may include multiple (e.g., N) power modules, multiple (e.g., N) DC-side electrolytic capacitors C, multiple (e.g., N) energy storage battery modules, and (e.g., 1) AC-side filter inductor (AC filter inductor) L, where N is a natural number greater than 1. Each energy storage battery module may include at least one parallel branch, and each parallel branch may include multiple energy storage battery modules connected in series. The N power modules are connected in series and connected to the power grid through the AC-side filter inductor. Each battery module in the N battery modules is electrically connected to the DC side of the corresponding power module in the N power modules, and each electrolytic capacitor C in the N DC-side electrolytic capacitors C is connected in parallel to the DC side of the corresponding power module. Each power module includes a bridge circuit composed of multiple IGBTs (modules).

[0053] For MW-level H-bridge chain-type large-capacity energy storage power conversion systems required in 10kV and above high-voltage distribution or transmission networks, this invention proposes a multi-objective parameter optimization design method for H-bridge chain-type energy storage power conversion systems, comprehensively considering two key objectives: material cost and output voltage quality. This method can ensure optimal output voltage quality while minimizing material costs.

[0054] Since the reliability of an energy storage system depends entirely on the number of redundant devices or modules, both the reliability and cost of the system increase exponentially with the increase of redundant devices. Simultaneously, the switching frequency falls within the design scope of the control system; at a given switching frequency, both system efficiency and cost are directly proportional to the number of power devices. Therefore, for a power conversion system with a fixed topology and switching frequency, there is no optimal problem regarding its operational reliability and system efficiency. Furthermore, at a given switching frequency, the number of redundant devices has no impact on the power quality of the power conversion system. Therefore, this embodiment of the invention only comprehensively considers two optimization objectives: power quality and system cost.

[0055] The first step is to calculate the capacity of a single energy storage battery module corresponding to each power module and the number of energy storage battery modules connected in series in the energy storage battery module corresponding to a single power conversion module according to formula (1):

[0056]

[0057] In the formula, Q nom The capacity of a single energy storage battery module is given by δ, the maximum depth of discharge of the energy storage battery module is given by δ, typically 0.5–0.8; σ is the maximum grid voltage fluctuation rate is given by σ, typically 0.05–0.1; W T_nom V represents the total capacity of the entire energy storage battery system. snom ω is the effective value of the rated phase voltage of the power grid; I is the rated angular frequency of the power grid voltage; nomThe rated current of the energy storage power conversion system is given by n; L is the inductance of the AC side filter inductor of the energy storage power conversion system; n is the rated current of the energy storage power conversion system. Hz E represents the number of parallel branches in the energy storage battery module. nom The rated voltage of the energy storage battery module in the energy storage battery module; n Hm N represents the number of energy storage battery modules connected in series in each parallel branch of the energy storage battery module; N represents the number of power modules in the single-phase H-bridge chain energy storage power conversion circuit.

[0058] The second step involves understanding that the unit cost of the AC-side filter inductor in a high-voltage direct-connected H-bridge chain power conversion system is related to its rated voltage, current, and inductance value. However, the rated voltage and current of the AC-side filter inductor are only related to the AC bus voltage level U of the power conversion system. T_ac and the rated power P of the power conversion system t Since the value of AC-side filter inductance is independent of the value of N, only the relationship between the AC-side filter inductance and the number of power modules N in a single-phase H-bridge chain power conversion circuit needs to be considered. To reduce the total system cost, the AC-side filter inductance can be set to the minimum required value. Therefore, the formulas for calculating the AC-side filter inductance and its rated current, and the DC-side capacitance and rated voltage of a single power module in the H-bridge chain energy storage power conversion system are as follows:

[0059]

[0060] In the formula, I L U is the rated current value of the AC side filter inductor of the energy storage power conversion system; C is the capacitance value of the DC side electrolytic capacitor of the power module; U c_N f is the rated voltage of the DC-side electrolytic capacitor of the power module; f1 is the rated frequency of the mains voltage; f s I represents the switching frequency of the IGBT (Insulated Gate Bipolar Transistor) in the power module; ac This represents the output current value of the energy storage power conversion system.

[0061] The third step is to calculate the total material cost of the H-bridge chain energy storage power conversion system and the constraints on the number of power modules in the single-phase H-bridge chain energy storage power conversion system according to equation (3):

[0062]

[0063] In the formula, S IGBT S represents the unit cost of an IGBT. C S represents the unit cost of the DC-side electrolytic capacitor. L The unit cost of the AC-side filter inductor; U dcM represents the rated DC voltage of the power module; M represents the number of IGBTs contained in a single power module with different topologies. When the power module in the single-phase H-bridge chain power conversion circuit is an H-full-bridge converter structure, M = 4; when the power module in the single-phase H-bridge chain power conversion circuit is an H-half-bridge converter structure, M = 2.

[0064] Since the more power modules N in a single-phase H-bridge chain power conversion circuit, the more output voltage levels (2N+1) the energy storage power conversion system has, the output current quality of the energy storage power conversion system shows a positive correlation with the number of power modules N in the single-phase H-bridge chain power conversion circuit. According to equation (3), when the unit cost of the device is constant, the more power modules N per phase, the higher the total material cost. The unit cost of the device and the number of power modules N in a single phase show an inverse correlation. Furthermore, there is an intrinsic relationship between the unit cost of the device and the number of power modules N per phase. Therefore, there is an optimal design scheme for the total material cost between the number of power modules N per phase and the unit cost of the device.

[0065] The fourth step, in order to establish the objective function for optimizing key parameters, requires establishing a mathematical relationship between the unit cost of each component and the number of power modules N per phase. For quantitative calculation, in the total material cost calculation function of the H-bridge chain power conversion system, the rated voltage U of a single IGBT is used. IGBT With current value I IGBT Based on meeting the minimum design requirements (U) IGBT =2U dc I IGBT =2I N If the values ​​are taken, the formulas for calculating the rated voltage and current of a single IGBT are:

[0066]

[0067] In the formula, I N P is the rated current of the H-bridge chain power conversion system. t This refers to the rated power of the energy storage power conversion system.

[0068] In actual products, the rated voltage of electrolytic capacitors suitable for the DC side of high-capacity power modules is basically only three levels: 400V, 450V, and 500V. U is determined based on the calculation results of formula (2) and the actual product voltage level of the electrolytic capacitor. c_N The final value of U. c_N Once the value of C is determined, the brand of the electrolytic capacitor is selected based on project requirements. The cost of the electrolytic capacitor is then only related to its capacitance value C. After determining the brands of the IGBT, electrolytic capacitor, and AC-side filter inductor, the unit costs of the IGBT, electrolytic capacitor, and AC-side filter inductor are respectively related to U. IGBTThe functions of C and L can be used to obtain the unit cost of IGBTs, electrolytic capacitors, and AC-side filter inductors relative to U, based on the market prices of IGBTs, electrolytic capacitors, and AC-side filter inductors, using a data fitting method. IGBT Functional expressions for C and L:

[0069]

[0070] In the formula, k1, k2, k3, and k4 are the coefficients of the unit cost function expression of IGBT, electrolytic capacitor, and AC side filter inductor, respectively, and their values ​​can be obtained by surveying market prices and data fitting methods.

[0071] Considering the actual voltage level of the IGBT products that can be used in the high-capacity power conversion system, the rated parameter calculation formulas of IGBT and AC side filter inductor in the H-bridge chain energy storage power conversion system can be obtained from equations (1), (2), (3), and (5) as shown in equation (6), and the objective function for the design optimization of key parameters of the H-bridge chain energy storage power conversion system is shown in equation (7).

[0072]

[0073]

[0074] Figure 3 An example flowchart illustrating the key parameter optimization design method for an H-bridge chain energy storage power conversion system according to an embodiment of the present invention is shown. Figure 3 As shown, the parameter optimization method for an H-bridge chain energy storage power conversion system may include the following steps.

[0075] The AC bus voltage of the three-phase high-voltage direct-connected H-bridge chain energy storage power conversion system is U. T_ac Rated capacity is P t When the power module in a single-phase circuit is an H-bridge converter, M=4; when the power module in a single-phase circuit is an H-half-bridge converter, M=2. The parameter optimization design method for a three-phase high-voltage direct-connected H-bridge chain-type energy storage power conversion system is as follows:

[0076] First, determine the total capacity P of the three-phase H-bridge chain energy storage power conversion system. t AC bus voltage level U T_ac The number of parallel branches n of the energy storage battery modules in the energy storage battery module Hz Power module structure and number of IGBTs M, AC bus voltage frequency f1, switching frequency f s and P t U T_ac and the selected electrolytic capacitor's rated voltage U DC_N Substituting into equation (6), we can obtain

[0077]

[0078] Based on the calculation results of equation (8) and the current rating of the IGBT product, select I IGBT The final value.

[0079] Then, the relationship between the unit cost and rated voltage of IGBTs, the relationship between the unit cost and rated capacitance of electrolytic capacitors, and the relationship between the AC side filter inductor and rated inductance were investigated. A function expression for the unit cost of components was obtained through data fitting, and the coefficients of each unit cost function expression were set to k1, k2, k3, and k4 (these coefficients were determined based on the component model and market price during data fitting). Then, we have...

[0080]

[0081] Substituting equations (2) and (4) into equation (7), we can obtain the relationship between the unit cost of IGBTs, electrolytic capacitors, and AC-side filter inductors and the number of power modules per phase, N.

[0082]

[0083] Substituting equation (10) into equation (7), we can obtain the following formula for calculating the total material cost of the H-bridge PCS:

[0084]

[0085] Based on the above calculation results and known design parameters, the key parameter optimization objective function for the three-phase H-bridge chain energy storage power conversion system can be obtained as follows:

[0086]

[0087] Secondly, substituting the relevant parameters into the first row of equation (12) yields the total material cost function with the number of single-phase power modules N in the PCS (Power Conversion System) as the variable. Based on the total material cost function, the total material cost curve of the H-bridge chain PCS system with the number of power modules N in the single-phase circuit as the variable can be obtained. The goal is to achieve the lowest total material cost and the best output current waveform quality for the H-bridge chain power conversion system, i.e., to obtain the best output current waveform quality at the same cost. Therefore, the method for determining the value of the number of power modules N in the single-phase circuit is as follows:

[0088] 1) The value of N makes U dc The minimum value satisfies the IGBT rated voltage safety factor (e.g., 12) and cost factor (e.g., 12.5);

[0089] 2) Within a range where costs are essentially the same, N takes the maximum value;

[0090] 3) N takes an even number.

[0091] Finally, the determined optimal N value is substituted into equation (12), and the final parameter value is determined based on the actual product rating, manufacturing process, cost, and other factors of the components, according to the other parameter selection methods as follows:

[0092] 1) It satisfies the conditions of equality or inequality;

[0093] 2) Meets the actual product's rated parameter level and processing technology;

[0094] 3) Take values ​​within 10% of the limit of the inequality.

[0095] Based on the above calculation results, the N and U values ​​in the three-phase high-voltage direct-connected H-bridge chain power conversion system can finally be obtained. dc L, C, Q nom n Hm U IGBT Optimized design values ​​for key parameters such as...

[0096] This invention provides an H-bridge chain energy storage power conversion system manufactured using the parameter optimization method for H-bridge chain energy storage power conversion systems described in any of the above embodiments.

[0097] This invention provides a processor configured to execute the parameter optimization method for an H-bridge chain energy storage power conversion system described in any of the above embodiments.

[0098] This invention provides a parameter optimization device for an H-bridge chain energy storage power conversion system, comprising:

[0099] The objective function determination module is configured to determine the key parameter design optimization objective function of the H-bridge chain energy storage power conversion system.

[0100] The value selection module is configured to design and optimize the objective function based on the key parameters, with the goal of minimizing the total material cost and optimizing the output current waveform quality of the H-bridge chain energy storage power conversion system, and to select the value of the number N of power modules in the single-phase H-bridge chain power conversion circuit of the H-bridge chain energy storage power conversion system.

[0101] The parameter determination module is configured to substitute the determined N value into the key parameter design optimization objective function, and, in conjunction with the actual product's rated parameter level, manufacturing process, and cost factors, determine other parameters of the component. These other parameters include at least the DC-side rated voltage U of the power module. dc The inductance value L of the AC side filter inductor, the capacitance value C of the electrolytic capacitor, and the capacity Q of a single energy storage battery module.nom The number of energy storage battery modules connected in series in each parallel branch of the energy storage battery module, n Hm The rated voltage U of a single IGBT IGBT .

[0102] This invention provides a machine-readable storage medium storing instructions that, when executed by a processor, cause the processor to implement the parameter optimization method for an H-bridge chain energy storage power conversion system described in any of the above embodiments.

[0103] The multi-objective parameter optimization design scheme of the H-bridge chain energy storage power conversion system provided in this embodiment of the invention optimizes the total material cost and output voltage quality of the energy storage power conversion system, while ensuring that other parameters meet the system operation requirements.

[0104] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application 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.

[0105] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. 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, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0106] 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, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0107] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0108] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0109] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0110] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0111] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0112] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A parameter optimization method for an H-bridge chain-type energy storage power conversion system, characterized in that, The parameter optimization method includes: Determine the objective function for designing and optimizing the key parameters of the H-bridge chain energy storage power conversion system; Based on the aforementioned key parameters, an optimization objective function is designed. The goal is to minimize the total material cost and optimize the output current waveform quality of the H-bridge chain energy storage power conversion system. This involves adjusting the number of power modules in the single-phase H-bridge chain power conversion circuit of the H-bridge chain energy storage power conversion system. N To retrieve values; To be determined N Substituting the values ​​into the key parameters, the design optimization objective function is used. Combined with the actual rated parameter levels, manufacturing processes, and cost factors of the components, other parameters of the components are determined. These other parameters include at least the DC-side rated voltage of the power module. The inductance value of the AC side filter inductor The capacitance value of an electrolytic capacitor Capacity of a single energy storage battery module The number of energy storage battery modules connected in series in each parallel branch of the energy storage battery module Rated voltage of a single IGBT ; The objective function for optimizing the key parameters is defined as follows: in, S SUM The total material cost of the H-bridge chain energy storage power conversion system is... N This refers to the number of power modules in a single-phase H-bridge chained power conversion circuit. The AC bus voltage of the H-bridge chain energy storage power conversion system is [not specified]. I ac This refers to the single-phase output current of the energy storage power conversion system. The rated angular frequency of the grid voltage. f 1 represents the AC bus voltage frequency. f s The switching frequency of the IGBT. U IGBT The rated voltage for a single IGBT. The inductance value of the AC side filter inductor. C This refers to the capacitance value of the electrolytic capacitor. Q nom For the capacity of a single energy storage battery module, W T_nom The total capacity of the energy storage battery system. This represents the maximum depth of discharge value of the energy storage battery module. This represents the maximum voltage fluctuation rate of the power grid. This refers to the rated voltage of the energy storage battery module in the energy storage battery module. This refers to the rated current value of the H-bridge chain energy storage power conversion system. n Hz This refers to the number of parallel branches in a single energy storage battery module. This is the effective value of the rated phase voltage of the power grid. This refers to the number of energy storage battery modules connected in series in each parallel branch of the energy storage battery module. , These are the coefficients in the unit cost function expression of IGBT. , These are the coefficients of the unit cost function expressions for the electrolytic capacitor and the AC-side filter inductor, respectively, when the power module is an H-bridge converter structure. When the power module is an H-half-bridge converter structure, .

2. The parameter optimization method according to claim 1, characterized in that, The methods for determining the values ​​of the other parameters include: The objective function for designing and optimizing the key parameters must satisfy the equations or inequalities. Meets the actual product's rated parameter level and processing technology; The value is taken within 10% of the limit value of the inequality in the objective function for key parameter design optimization.

3. The parameter optimization method according to claim 1, characterized in that, The value of N satisfies the following principle: The value of N makes U dc The minimum value satisfies the IGBT rated voltage safety factor and cost factor; Within the range of costs, N takes the maximum value; N takes an even number.

4. The parameter optimization method according to claim 3, characterized in that, The IGBT rated voltage safety factor and cost factor are respectively and .

5. The parameter optimization method according to claim 1, characterized in that, The objective function for designing and optimizing the key parameters of the H-bridge chain energy storage power conversion system includes: Determine the AC bus voltage of the H-bridge chain energy storage power conversion system Rated capacity Number of parallel branches in a single energy storage battery module n Hz Power module structure type, number of IGBTs (M) in a single power module, AC bus voltage frequency. f 1. IGBT switching frequency f s and the rated voltage of the selected electrolytic capacitor. ; The rated capacity AC bus voltage and rated voltage Substitute into the following formula to calculate the rated voltage of a single IGBT. U IGBT and current I IGBT Rated voltage of electrolytic capacitors and the rated current of the AC side filter inductor. : Based on the calculated IGBT current I IGBT Select the current rating of the chosen IGBT product. I IGBT The final value; The relationship between the unit cost of IGBT and its rated voltage, the relationship between the unit cost of electrolytic capacitor and its rated capacitance, and the relationship between the AC side filter inductor and its rated inductance were determined. The unit cost function expression of each component was obtained through data fitting. Based on the unit cost function expressions for each component, the first relationship between the unit cost of IGBTs, electrolytic capacitors, and AC-side filter inductors and the number of power modules N in a single-phase H-bridge power conversion circuit is determined: in, S IGBT The unit cost of IGBTs S C The unit cost of DC-side electrolytic capacitors. S L The unit cost of the AC-side filter inductor; Based on the first relationship, the formula for calculating the total material cost of the H-bridge chain energy storage power conversion system is determined as follows: Based on the total material cost calculation formula and known design parameters, determine the key parameter design optimization objective function for the H-bridge chain energy storage power conversion system.

6. The parameter optimization method according to claim 1, characterized in that, The value range is from 0.5 to 0.

8. The value range is from 0.05 to 0.

1.

7. An H-bridge chain energy storage power conversion system manufactured using the parameter optimization method for an H-bridge chain energy storage power conversion system according to any one of claims 1 to 6.

8. A parameter optimization device for an H-bridge chain-type energy storage power conversion system, characterized in that, include: The objective function determination module is configured to determine the key parameter design optimization objective function of the H-bridge chain energy storage power conversion system. The value-selection module is configured to design and optimize an objective function based on the key parameters, aiming to minimize the total material cost and optimize the output current waveform quality of the H-bridge chain energy storage power conversion system, and to optimize the number of power modules in the single-phase H-bridge chain power conversion circuit of the H-bridge chain energy storage power conversion system. N To retrieve values; The parameter determination module is configured to determine the parameters. N Substituting the values ​​into the key parameters, the design optimization objective function is used. Combined with the actual rated parameter levels, manufacturing processes, and cost factors of the components, other parameters of the components are determined. These other parameters include at least the DC-side rated voltage of the power module. The inductance value of the AC side filter inductor The capacitance value of an electrolytic capacitor Capacity of a single energy storage battery module The number of energy storage battery modules connected in series in each parallel branch of the energy storage battery module Rated voltage of a single IGBT ; The objective function for optimizing the key parameters is defined as follows: in, S SUM The total material cost of the H-bridge chain energy storage power conversion system is... N This refers to the number of power modules in a single-phase H-bridge chained power conversion circuit. The AC bus voltage of the H-bridge chain energy storage power conversion system is [not specified]. I ac This refers to the single-phase output current of the energy storage power conversion system. The rated angular frequency of the grid voltage. f 1 represents the AC bus voltage frequency. f s The switching frequency of the IGBT. U IGBT The rated voltage for a single IGBT. The inductance value of the AC side filter inductor. C This refers to the capacitance value of the electrolytic capacitor. Q nom For the capacity of a single energy storage battery module, W T_nom The total capacity of the energy storage battery system. This represents the maximum depth of discharge value of the energy storage battery module. This represents the maximum voltage fluctuation rate of the power grid. This refers to the rated voltage of the energy storage battery module in the energy storage battery module. This refers to the rated current value of the H-bridge chain energy storage power conversion system. n Hz This refers to the number of parallel branches in a single energy storage battery module. This is the effective value of the rated phase voltage of the power grid. This refers to the number of energy storage battery modules connected in series in each parallel branch of the energy storage battery module. , These are the coefficients in the unit cost function expression of IGBT. , These are the coefficients of the unit cost function expressions for the electrolytic capacitor and the AC-side filter inductor, respectively, when the power module is an H-bridge converter structure. When the power module is an H-half-bridge converter structure, .

9. A machine-readable storage medium, characterized in that, The machine-readable storage medium stores instructions that, when executed by a processor, cause the processor to implement the parameter optimization method for an H-bridge chain energy storage power conversion system according to any one of claims 1 to 6.

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