Large-scale new energy diode phase-shift rectifier sending topology and method

Abstract

The application discloses a large-scale new energy diode phase-shift rectifier sending-out topology and method, wherein multiple diode phase-shift rectifier sending-out topologies are determined according to AC side harmonic and DC side ripple requirements; the distribution quantity of phase-shift parallel transformer groups is determined according to the number of diode phase-shift rectifier sending-out topologies, and the equivalent reconstruction of multi-winding phase-shift characteristics is realized through an arithmetic progression phase-shift angle sequence; the phase-shift angle of each phase-shift parallel transformer group is controlled by adopting a winding extension edge connection mode, and the DC sides of all diode rectifier units are connected in series to form a high-voltage output loop; the capacity and voltage parameters of the phase-shift parallel transformer group are determined in combination with the diode phase-shift rectifier topology structure, new energy generation capacity and AC / DC system voltage grade. The application is favorable for realizing the engineering application of the diode phase-shift rectifier, which is a low-cost, light-weight and high-reliability topology, in a large-scale new energy sending-out scene.

Description

Technical Field

[0001] This invention belongs to the field of DC transmission technology for new energy power generation, specifically relating to a large-scale new energy diode phase-shifting rectification transmission topology and method. Background Technology

[0002] High Voltage Direct Current (HVDC) technology has become the preferred solution for large-scale transmission of new energy power generation due to its outstanding advantages in large-capacity and long-distance transmission.

[0003] Currently, HVDC converters commonly use modular multilevel converters (MMCs) as their core topology. However, with the increasing installed capacity and transmission distance of new energy power generation, the size, weight, and cost of MMCs have risen sharply, severely hindering the achievement of grid parity for new energy. Diode-rectified (DR) HVDC (DR-HVDC) transmission schemes offer significant advantages in terms of lightweight design and economy, attracting widespread attention from academic and industrial communities both domestically and internationally. However, due to the strong nonlinear conduction characteristics of DRs, conventional DR-HVDC systems suffer from severe mid- and low-frequency harmonic distortion on the AC side, requiring the addition of numerous passive filters and reactive power compensation devices to reduce system harmonic content and reactive power components, thus diminishing the lightweight and economical technical advantages of the DR-HVDC scheme. Based on this, the industry has proposed an HVDC (PSDR-HVDC) transmission scheme based on diode phase-shifted rectifier (PSDR). This scheme introduces a multi-winding phase-shifted transformer (PST) to replace the conventional converter transformer and construct a series multiplexing topology, which greatly reduces the harmonic content on the AC side of the system. It is expected to reduce or even completely eliminate passive filter devices, thereby further reducing the size, weight and investment cost of HVDC converter valves. This is of great significance for realizing the large-scale development, efficient transmission and grid parity of new energy power generation.

[0004] However, existing research on PSDR-HVDC transmission systems is based on an idealized multi-winding centralized PST topology. While this topology possesses the universality and applicability of theoretical analysis, in practical engineering applications of large-scale renewable energy power generation, the multi-winding centralized PST struggles to overcome limitations in platform space and transportation constraints, and the electromagnetic coupling design and insulation manufacturing processes between windings are extremely challenging. These engineering difficulties prevent existing PSDR transmission topologies from meeting the requirements of large-scale, long-distance renewable energy power generation engineering applications.

[0005] Therefore, it is urgent to overcome the engineering limitations of multi-winding PSTs, study PSDR topology construction methods that meet the needs of large-scale new energy base construction, and fully ensure the feasibility of the technical advantages of PSDR-HVDC transmission schemes. Summary of the Invention

[0006] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a large-scale new energy diode phase-shifting rectification power transmission topology and method. This invention solves the technical problems of difficult manufacturing and transportation and installation of PSDR topology equipment based on multi-winding centralized PST in the prior art, and is conducive to realizing the engineering application of PSDR, a low-cost, lightweight and highly reliable topology, in new energy power transmission scenarios.

[0007] The present invention adopts the following technical solution:

[0008] A method for large-scale new energy diode phase-shifting rectification and power transmission includes the following steps:

[0009] The multiplicity of the diode phase-shifting rectifier output topology is determined based on the AC side harmonics and DC side ripple requirements.

[0010] The number of phase-shifting parallel transformer groups is determined based on the topological multiplicity of the diode phase-shifting rectifier output, and the equivalent reconstruction of the phase-shifting characteristics of the multi-winding is achieved through the equal arithmetic phase-shifting angle sequence.

[0011] The phase shift angle of each phase-shifting parallel transformer group is controlled by the winding extension connection method, and the DC side of all diode rectifier units are connected in series to form a high-voltage output circuit;

[0012] The capacity and voltage parameters of the phase-shifting parallel transformer group are determined by combining the diode phase-shifting rectifier topology, the new energy power generation capacity, and the AC / DC system voltage level.

[0013] Preferably, the multiplicity of the diode phase-shift rectifier output topology is as follows:

[0014]

[0015] in, It is a multiple. It is a set of positive integers. The total harmonic distortion (THD) of the alternating current. The maximum allowable AC harmonics for actual system operation. This refers to the DC-side voltage ripple factor. This represents the maximum DC ripple.

[0016] Preferably, the number of phase-shifting parallel transformer groups is determined based on the topological multiplicity of the diode phase-shifting rectifier output, and the equivalent reconstruction of the multi-winding phase-shifting characteristics is achieved through an equal arithmetic phase-shifting angle sequence, specifically as follows:

[0017] Let the number of secondary windings of each phase-shifting parallel transformer group be... n , to obtain the distribution quantity ;

[0018] The phase shift angle corresponding to the diode rectifier unit θ i Construct an arithmetic sequence and determine the common difference Δ of the arithmetic sequence. θ The phase shift angle difference between the secondary windings of the phase-shifted parallel transformer group is 60°. n ,when n When Δ = 2, the phase shift angle sequence is equivalently reconstructed to obtain Δ. θ .

[0019] Preferably, the number of distributions for:

[0020]

[0021] in, It is a multiple.

[0022] Preferably, the tolerance Δ θ for:

[0023]

[0024] in, , For the 2nd i The phase shift angle corresponding to the diode rectifier unit For the 2nd i -1 Phase shift angle corresponding to the diode rectifier unit For the 2nd i +1 phase shift angle corresponding to the diode rectifier unit.

[0025] Preferably, the phase shift angle of each phase-shifting parallel transformer group is controlled by a winding-extended connection method, and the DC sides of all diode rectifier units are connected in series to form a high-voltage output circuit, specifically:

[0026] Phase shifting can be performed using either the secondary winding phase shifting method or the primary winding phase shifting method.

[0027] The phase-shifting winding of the phase-shifting parallel transformer group adopts two symmetrical extension forms, namely reverse extension and forward extension, to achieve the control of the phase-shifting angle.

[0028] Preferably, when the secondary winding extends along the phase shift method, there is N Build a PSPT M Each secondary winding undergoes phase shifting along its side, and the phases of the secondary windings satisfy the phase shift angle sequence;

[0029] When using the primary winding phase-shifting method, there is N Build a PSPT N One primary winding undergoes phase shifting along its side, and all secondary windings are connected in a Y / d configuration to induce primary electromotive force. At this time, the phases of the secondary windings satisfy the phase shift angle sequence.

[0030] Preferably, the phase-shifting parallel transformer group adopts a symmetrical arrangement to reduce the design cost of the equipment. In this case, the first term of the phase-shifting angle sequence is... θ 1 represents the inverse phase shift angle, as detailed below:

[0031]

[0032] in, It is a multiple.

[0033] Preferably, when the PSPT secondary winding is in phase-shifting mode, the output composite voltage is... U o = U s When the PSPT uses the primary winding phase-shifting method, the output composite voltage is... U o = U p The output synthesized voltage is based on the voltage ratings of the initial and extended windings, i.e.:

[0034]

[0035] in, This is the initial winding voltage after phase shift. For phase shift angle, This is the voltage of the phase-shifted extension winding.

[0036] Secondly, embodiments of the present invention provide a diode phase-shifting rectifier output topology for a new energy power generation base, including a phase-shifting parallel transformer group and a diode rectifier unit. The primary winding of the phase-shifting parallel transformer group is connected in parallel to the AC busbar, and the secondary winding is connected to the diode rectifier unit. The DC side of the diode rectifier unit is connected in series in sequence according to the phase shift angle sequence.

[0037] For the secondary winding phase-shifting method, the primary winding adopts a Y-type connection, and the secondary windings adopt d-type phase-shifting connections, totaling... N Group of phase-shifting parallel transformers M Each secondary winding undergoes phase shifting along its side, and the phases of the secondary windings satisfy the phase shift angle sequence;

[0038] For the primary winding phase-shifting method, the primary winding adopts a d-type phase-shifting connection, and the secondary winding adopts a Y / d-type connection to induce the primary electromotive force. There are a total of...N Group of phase-shifting parallel transformers N The primary winding undergoes phase shifting along its side, and the phase of the secondary winding satisfies the phase shift angle sequence.

[0039] Thirdly, a computer device includes 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 steps of the above-described large-scale new energy diode phase-shifting rectification and power-out method.

[0040] Fourthly, embodiments of the present invention provide a computer-readable storage medium including a computer program, which, when executed by a processor, implements the steps of the above-described large-scale new energy diode phase-shifting rectification and power-out method.

[0041] Fifthly, a chip includes 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 steps of the above-described large-scale new energy diode phase-shifting rectification and power-out method.

[0042] In a sixth aspect, embodiments of the present invention provide an electronic device, including a computer program, which, when executed by the electronic device, implements the steps of the above-described large-scale new energy diode phase-shifting rectification and power-out method.

[0043] Compared with the prior art, the present invention has at least the following beneficial effects:

[0044] A large-scale new energy diode phase-shifted rectification and transmission method is proposed, which constructs a PSDR transmission topology for new energy power generation bases based on phase-shifted parallel transformers (PSPTs). On the one hand, compared with multi-winding centralized PSTs, the structure of PSPTs can reduce the rated capacity and voltage level of individual transformers, while ensuring safe insulation gaps between windings, thereby reducing the difficulty of equipment design, manufacturing, transportation and installation. On the other hand, each PSPT has a specific phase shift angle, which enables the PSDR transmission topology to have multiple external characteristics while effectively reducing the harmonic distortion inside the transformer itself, thereby ensuring the overall stable and reliable operation of the new energy power generation and transmission system.

[0045] Furthermore, by increasing the multiplexing number of the rectifier topology and utilizing the phase superposition effect of phase-shifting technology, AC-side harmonics and DC-side ripple can be reduced. Multiplexed phase-shifting rectification can cancel harmonics of a specific order by superimposing different phase angles, reducing harmonic pollution to the power grid. The output superposition of multiple rectifier units on the DC side can smooth DC voltage pulsations and reduce the impact on energy storage devices or inverters. It meets the grid's mandatory standards for harmonic distortion rate and DC ripple coefficient, avoiding grid connection restrictions caused by excessive harmonics.

[0046] Furthermore, based on the multiplicity of the rectifier topology, a corresponding number of phase-shifting transformer groups are configured, and equivalent phase-shifting characteristics are achieved through an equal-aberration phase-shifting angle sequence. The equal-aberration phase-shifting angle sequence ensures that the output phase of each rectifier unit is evenly distributed, maximizing the harmonic cancellation effect. By replacing the complex physical phase-shifting structure with mathematical equivalence, the complexity of transformer design is reduced. By increasing or decreasing the number of parallel transformer groups, different capacity and voltage level requirements can be flexibly adapted.

[0047] Furthermore, by adopting a transformer winding extension connection method, the phase shift angle is precisely controlled, and the DC output of each rectifier unit is connected in series to form a high-voltage circuit. The extension connection achieves precise phase shift angle adjustment by adjusting the winding turns ratio, avoiding the accumulation of phase error. The voltages of each unit are superimposed in series on the DC side, achieving high DC voltage output without additional boosting equipment, thus reducing equipment costs. In the series structure, the failure of a single rectifier unit only affects part of the voltage, and the system can still operate at a reduced rating, improving fault tolerance.

[0048] Furthermore, by combining the diode rectifier topology, the capacity of new energy power generation, and the AC / DC voltage levels, the capacity and voltage parameters of the phase-shifting transformer group are optimized; the transformer capacity is ensured to match the output of new energy power generation, avoiding capacity waste or overload risks; the manufacturing cost of the transformer is reduced through the reasonable allocation of voltage levels and capacity; and the AC / DC side voltage parameters are standardized to simplify the design of subsequent converters and grid-connected equipment.

[0049] It is understood that the beneficial effects of the second to sixth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.

[0050] In summary, this invention significantly suppresses harmonics and DC ripple and reduces filtering costs through multi-phase-shift rectification and transformer differential phase-shift reconstruction; DC series connection enables high-voltage direct transmission, eliminating the need for step-up equipment; the modular design balances flexible expansion and high fault tolerance, making it suitable for long-distance power transmission from wind, solar and energy storage bases, and combining high efficiency, economy and reliability.

[0051] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0052] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a flowchart of the method of the present invention;

[0054] Figure 2 This is a basic structure diagram of Photoshop;

[0055] Figure 3 Send the topology diagram for PSDR, where (a) is the phase shift along the secondary winding and (b) is the phase shift along the primary winding.

[0056] Figure 4 This is a diagram of the PSPT phase-shifting winding structure.

[0057] Figure 5 A schematic diagram of the process of transmitting topological harmonics to a PSDR;

[0058] Figure 6 A schematic diagram of the commutation process of the topology DR unit for PSDR output;

[0059] Figure 7 Send the harmonic characteristic curves of the PSDR topology;

[0060] Figure 8 Send the reactive power characteristic curve of the PSDR topology;

[0061] Figure 9 Send the AC voltage / current waveform diagram of the PSDR topology;

[0062] Figure 10 The AC current harmonic spectrum diagram of the PSDR topology is provided.

[0063] Figure 11 Send the active / reactive power waveform diagram of the PSDR topology;

[0064] Figure 12 The diagram shows the internal current waveform and harmonic spectrum of the PSPT, where (a) is before phase shift sequence reconstruction and (b) is after phase shift sequence reconstruction.

[0065] Figure 13 Diagram of the overall structure and control scheme of the PSDR power transmission system for deep-sea wind power;

[0066] Figure 14 Active / reactive power waveforms for the PSDR power delivery system for deep-sea wind power;

[0067] Figure 15 The AC voltage / current waveforms of the deep-sea wind power PSDR transmission system are shown, where (a) is the PSDR side and (b) is the wind turbine side.

[0068] Figure 16 The AC current harmonic spectrum diagram of the deep-sea wind power PSDR transmission system is shown, where (a) is the PSDR side and (b) is the wind turbine side.

[0069] Figure 17 A schematic diagram of a computer device provided in an embodiment of the present invention;

[0070] Figure 18 This is a block diagram of an electronic device according to an embodiment of the present invention.

[0071] Among them, 60. Computer equipment; 61. Processor; 62. Memory; 63. Computer program; 600. Electronic device; 610. Processing unit; 620. Storage unit; 6201. Random access memory unit; 6202. Cache memory unit; 6203. Read-only memory unit; 6204. Program / utility; 6205. Program module; 630. Bus; 640. Display unit; 650. Input / output interface; 660. Network adapter; 700. External device. Detailed Implementation

[0072] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0073] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0074] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0075] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0076] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0077] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0078] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0079] This invention provides a large-scale new energy diode phase-shifting rectifier (PSDR) power transmission topology and method. The method determines the multiplexing factor of the PSDR power transmission topology based on AC-side harmonics and DC-side ripple requirements; determines the number of PSPTs based on the PSDR power transmission topology multiplexing factor; and achieves equivalent reconstruction of the multi-winding phase-shifting characteristics through an arithmetic phase-shifting angle sequence. It controls the phase-shifting angle of each PSPT using a winding-extended connection method and connects the DC sides of all DR units in series to form a high-voltage output circuit. The method combines the PSDR topology, the new energy power generation capacity, and the rated capacity and voltage parameters of the PSPTs for AC / DC system voltage levels. Compared to PSDR power transmission topologies using multi-winding centralized PSTs, the advantage of this invention lies in reconstructing the PSDR power transmission topology through PSPTs, giving it completely consistent multiplexing external characteristics. It also reduces the design and manufacturing difficulty of transformer equipment, facilitates transportation and installation, and is beneficial for the engineering application of PSDR-HVDC power transmission schemes in new energy power generation bases.

[0080] Example 1

[0081] Please see Figure 1 This invention discloses a large-scale new energy diode phase-shifting rectification power transmission topology and method, comprising the following steps:

[0082] S1. Determine the multiplication factor of the PSDR output topology based on the AC side harmonics and DC side ripple requirements.

[0083] Let the multiplicity be M The total harmonic distortion (THD) of the AC side current is THD i DC side voltage ripple factor is Then the following relationship exists between the above physical quantities:

[0084]

[0085]

[0086] Considering the maximum allowable AC harmonics in actual system operation THD max and maximum DC ripple λ max Value, the multiplicity of the PSDR-output topology without a filter. M The following constraints must be met:

[0087]

[0088] The multiplicity of the PSDR output topology is determined by the above formula.

[0089] S2. Determine the number of PSPTs based on the topological multiplicity sent by PSDR, and realize the equivalent reconstruction of the phase shift characteristics of multi-winding through the equal arithmetic phase shift angle sequence;

[0090] S201. Let the number of secondary windings of each PSPT be... n Then its distribution quantity is:

[0091]

[0092] Preferably, considering that the current equipment manufacturing process for double secondary winding PSPTs is relatively mature, the present invention adopts... n =2 for analysis. It should be emphasized that the structure of PSPT may vary. n The values ​​of may vary, but the PSDR output topology construction method based on PSPT is within the scope of protection of this invention. The basic structure of PSPT is as follows: Figure 2 As shown;

[0093] S202, will Figure 2 Phase shift angle corresponding to the DR unit θ i If the sequence is constructed as an arithmetic progression, then the common difference Δ of this arithmetic progression is... θ for:

[0094]

[0095] To eliminate low-order harmonic distortion within the transformer, the phase shift angle difference between the secondary windings of the PSPT is required to be 60°. n ,when n When the phase shift angle is 2, the equivalent reconstruction of the phase shift angle sequence yields:

[0096]

[0097] S3. The phase shift angle of each PSPT is controlled by a winding-extended connection method, and the DC sides of all DR units are connected in series to form a high-voltage output circuit, such as... Figure 3 As shown.

[0098] S301. This invention provides two methods for constructing PSDR output topologies, both of which have the same phase-shifting effect.

[0099] Please see as follows Figure 3 A diode phase-shifting rectifier power output topology for a new energy power generation base includes:

[0100] The primary windings of each PSPT are connected in parallel to the AC busbar, and the secondary windings are connected to the DR units respectively. The DC sides of the DR units are then connected in series according to the phase shift angle sequence. Specifically, for... Figure 3(a) shows a secondary winding phase-shifting configuration where the primary winding uniformly adopts a Y-type connection, and the secondary windings respectively adopt a d-type phase-shifting connection. For example... Figure 3 (b) shows the primary winding phase shifting method, in which the primary winding adopts the d-type phase shifting connection type, and the secondary winding adopts the Y / d type connection type.

[0101] When adopting such Figure 3 When the secondary winding is shifted along the side as shown in (a), there are a total of N Build a PSPT M Each secondary winding undergoes phase shifting along its side, and the phases of the secondary windings satisfy the phase shift angle sequence;

[0102] When adopting such Figure 3 When the primary winding extends along the phase shifting method shown in (b), there are a total of N Build a PSPT N The primary windings undergo phase shifting along their sides, and all secondary windings adopt a uniform Y / d connection to induce primary electromotive force. At this time, the phases of the secondary windings also satisfy the phase shift angle sequence.

[0103] Preferably, adopting a primary winding extended phase-shifting structure can reduce the number of phase-shifting windings, reduce the design and manufacturing difficulty of PSPT, and the secondary side adopts a Y / d type connection, which can more accurately control the phase shift angle difference to 30°, and reduce the phase shift angle error caused by manufacturing precision.

[0104] S302 and PSPT phase-shifting windings can adopt two symmetrical extension forms: reverse extension and forward extension, thereby achieving control of the phase-shifting angle. The PSPT phase-shifting winding structure is as follows: Figure 4 As shown in the figure, A0-B0-C0 represents the initial three-phase winding, and A1-B1-C1 and A2-B2-C2 represent the three-phase composite windings after reverse and forward phase shifting, respectively. U 0、 U 1. U 2 represents the initial voltage, the reverse-delay combined voltage, and the forward-delay combined voltage, respectively. θ - and θ + These are the reverse and forward phase shift angles, defined in this invention. θ - <0, θ + >0.

[0105] Preferably, the PSPT adopts a symmetrical arrangement to reduce the design cost of the equipment. In this case, the first term of the phase shifting angle sequence... θ 1 represents the inverse phase shift angle, which is:

[0106]

[0107] S4. Combine the PSDR topology, new energy power generation capacity, and AC / DC system voltage level rating PSPT capacity and voltage parameters.

[0108] Assume the total power generation capacity of the new energy power generation base is S t The rated voltage of the AC collection system is U c The rated voltage of the DC transmission system is U d The rated capacity of a single PSPT is... S PSPT for:

[0109]

[0110] PSPT primary winding voltage U p The voltage rating of the AC collection system, the secondary winding voltage U s The voltage rating of the DC power supply system is as follows:

[0111]

[0112] When the secondary winding of the PSPT is in phase-shift mode, the output composite voltage is... U o = U s ;

[0113] When the PSPT adopts the primary winding phase-shifting method, the output composite voltage is... U o = U p .

[0114] The output synthesized voltage is based on the voltage ratings of the initial and extended windings, i.e.:

[0115]

[0116] Those skilled in the art will understand that various aspects of the present invention can be implemented as systems, methods, or program products. Therefore, various aspects of the present invention can be specifically implemented in the following forms: a completely hardware implementation, a completely software implementation (including firmware, microcode, etc.), or a combination of hardware and software aspects, collectively referred to herein as a "circuit," "module," or "platform."

[0117] Example 2

[0118] This invention provides a terminal device comprising a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, graphics processing units (GPUs), tensor processing units (TPUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions to achieve a corresponding method flow or function. The processor described in this embodiment can be used in the operation of a large-scale new energy diode phase-shifting rectification and power-out method, including:

[0119] The multiplicity of the diode phase-shifting rectifier output topology is determined based on the AC side harmonics and DC side ripple requirements. The number of phase-shifting parallel transformer groups is determined based on the multiplicity of the diode phase-shifting rectifier output topology, and the equivalent reconstruction of the multi-winding phase-shifting characteristics is achieved through an arithmetic phase-shifting angle sequence. The phase-shifting angle of each phase-shifting parallel transformer group is controlled by the winding extension connection method, and the DC side of all diode rectifier units is connected in series to form a high-voltage output circuit. The capacity and voltage parameters of the phase-shifting parallel transformer group are determined by combining the diode phase-shifting rectifier topology, the new energy power generation capacity, and the AC / DC system voltage level.

[0120] Please see Figure 17 The terminal device is a computer device. In this embodiment, the computer device 60 includes a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When the processor 61 executes the computer program 63, it implements the large-scale new energy diode phase-shifting rectification and power transmission method described in this embodiment. To avoid repetition, these details are not elaborated here. Alternatively, when the processor 61 executes the computer program 63, it implements the functions of each model / unit in the new energy power generation base diode phase-shifting rectification and power transmission topology construction system described in this embodiment. To avoid repetition, these details are not elaborated here.

[0121] Computer device 60 can be a desktop computer, laptop, handheld computer, cloud server, or other computing device. Computer device 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art will understand that... Figure 17 This is merely an example of computer device 60 and does not constitute a limitation on computer device 60. It may include more or fewer components than shown, or combine certain components, or different components. For example, computer device may also include input / output devices, network access devices, buses, etc.

[0122] The processor 61 may be a Central Processing Unit (CPU), or other general-purpose processors, graphics processing units (GPUs), tensor processing units (TPUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0123] The memory 62 can be an internal storage unit of the computer device 60, such as a hard disk or RAM of the computer device 60. The memory 62 can also be an external storage device of the computer device 60, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., provided on the computer device 60.

[0124] Furthermore, the memory 62 may include both internal storage units of the computer device 60 and external storage devices. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 can also be used to temporarily store data that has been output or will be output.

[0125] Please see Figure 18 The terminal device is an electronic device 600, which is manifested in the form of a general-purpose computing device. The components of the electronic device may include, but are not limited to: at least one processing unit 610, at least one storage unit 620, a bus 630 connecting different platform components (including storage unit 620 and processing unit 610), a display unit 640, etc.

[0126] The storage unit stores program code, which can be executed by the processing unit 610 to perform the steps described in the method section of this specification according to various exemplary embodiments of the present invention. For example, the processing unit 610 can perform actions such as... Figure 1 The steps are shown in the figure.

[0127] Storage unit 620 may include a readable medium in the form of a volatile storage unit, such as random access memory (RAM) 6201 and / or cache memory 6202, and may further include a read-only memory (ROM) 6203.

[0128] Storage unit 620 may also include a program / utility 6204 having a set (at least one) program module 6205, such program module 6205 including but not limited to: operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0129] Bus 630 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the multiple bus structures.

[0130] Electronic device 600 can also communicate with one or more external devices 700 (e.g., keyboard, pointing device, Bluetooth device, etc.), and with one or more devices that enable a user to interact with electronic device 600, and / or with any device that enables electronic device 600 to communicate with one or more other computing devices (e.g., router, modem). This communication can be performed via input / output interface 650. Furthermore, electronic device 600 can also communicate with one or more networks (e.g., local area network, wide area network, and / or public network, such as the Internet) via network adapter 660. Network adapter 660 can communicate with other modules of electronic device 600 via bus 630. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms.

[0131] Example 3

[0132] This invention also provides a storage medium, specifically a computer-readable storage medium, which is a memory device in a terminal device for storing programs and data. It is understood that the computer-readable storage medium here can include both built-in storage media in the terminal device and extended storage media supported by the terminal device; it can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by a processor, which can be one or more computer programs (including program code). More specific examples of the computer-readable storage medium include: an electrical connection with one or more wires, a portable disk, a hard disk, random access memory, read-only memory, erasable programmable read-only memory, optical fiber, portable compact disk read-only memory, optical storage device, magnetic storage device, or any suitable combination thereof.

[0133] Computer-readable storage media also include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable storage medium can also be any readable medium other than a readable storage medium that can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium can be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, radio frequency, etc., or any suitable combination thereof.

[0134] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0135] One or more instructions stored in a computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the large-scale new energy diode phase-shifting rectification and output method in the above embodiments; one or more instructions in the computer-readable storage medium are loaded and executed by the processor in the following steps:

[0136] The multiplicity of the diode phase-shifting rectifier output topology is determined based on the AC side harmonics and DC side ripple requirements. The number of phase-shifting parallel transformer groups is determined based on the multiplicity of the diode phase-shifting rectifier output topology, and the equivalent reconstruction of the multi-winding phase-shifting characteristics is achieved through an arithmetic phase-shifting angle sequence. The phase-shifting angle of each phase-shifting parallel transformer group is controlled by the winding extension connection method, and the DC side of all diode rectifier units is connected in series to form a high-voltage output circuit. The capacity and voltage parameters of the phase-shifting parallel transformer group are determined by combining the diode phase-shifting rectifier topology, the new energy power generation capacity, and the AC / DC system voltage level.

[0137] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0138] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0139] The PSDR transmission topology of the new energy power generation base constructed based on this invention is the same as the PSDR transmission topology based on multi-winding centralized PST in terms of operating principle and external characteristics. The AC system without a filter device has the advantages of low harmonic distortion and high power factor operation.

[0140] Regarding harmonic characteristics, the harmonic emission process of the PSDR transmission topology of the new energy power generation base constructed in this invention is as follows: Figure 5 As shown. Based on this harmonic emission process, the PSDR outputs the total harmonic current of the topology. ih It can be generally expressed by the following formula:

[0141]

[0142] in, Z L This is the equivalent load factor, which is affected by both the HVDC line and the receiving-end converter station. During steady-state operation of the renewable energy transmission system, the DC transmission system maintains constant voltage and current. Z L It can be regarded as a constant coefficient.

[0143] Substituting the arithmetic phase shift sequence constructed in step S2 of this invention into the above equation, the non-characteristic coupled subharmonic current component is eliminated, and the above equation is simplified to:

[0144]

[0145] As can be seen from the above equation, as the multiplicity of the PSDR output topology increases, the total harmonic current... i h The smaller the value, the lower the harmonic distortion of the AC system, and the higher the distribution frequency band of the characteristic coupled harmonics, which can completely eliminate the need for passive filtering devices.

[0146] Regarding reactive power characteristics, the reactive power generation of the PSDR topology of the new energy power generation base constructed in this invention is mainly dominated by the commutation process of the DR unit. Taking the voltage and current waveforms of phase A as an example for analysis, this process is as follows: Figure 6 As shown in the figure, u A , i A This represents the voltage and current of phase A in an AC system. u BC , u BA , u CA These represent the line voltages between phases BC, BA, and CA, respectively. u d , I d Represents DC voltage and current. γ The commutation overlap angle can be calculated using the following formula:

[0147]

[0148] in, X γ This indicates the leakage impedance of the PSPT.

[0149] also, i + , i- express i A The rising and falling currents are represented in segments as follows:

[0150]

[0151] By performing reactive power expansion on the fundamental component, the total reactive power generated by the PSDR output topology can be obtained as follows:

[0152]

[0153] Substituting the rated voltage from step S4 of this invention into the above formula, it can be seen that during steady-state operation of the new energy transmission system, the reactive power generated by the PSDR transmission topology is mainly affected by the number of PSPTs and their own leakage reactance. Since the conventional DR transmission topology used in new energy power generation bases also requires the installation of multiple converter transformers, the reactive power generated by the commutation process of the DR unit is similar to that of the PSDR transmission topology. However, the PSDR transmission topology can eliminate a large number of passive filter devices, thus significantly reducing the overall reactive power of the system and giving it the advantage of high power factor operation.

[0154] The PSDR topology for new energy power generation bases constructed in this invention achieves the effect of multiplexed rectification through PSPT. The above theoretical analysis shows that this topology has significant advantages such as low harmonic distortion and high power factor.

[0155] according to i h The calculation formula can be further used to obtain the THD of the AC system current in the PSDR output topology, and its curve as a function of the PSDR topology multiplicity can be plotted as follows. Figure 7 As shown, it can be seen that as the topological multiplicity of PSDR increases, THD i Significantly reduced, when M When large enough THD i Meeting the relevant power quality standards can completely eliminate the need for passive filtering devices.

[0156] according to Q The calculation formula can be used to obtain the system reactive power, the number of PSPT distributions, and its own leakage reactance. X γ The relationship between them is as follows Figure 8 As shown, it can be seen that the reactive component of the AC system is positively correlated with the PSPT leakage reactance. X γ When it is 0.1 pu Q The value is 0.276 pu. Since there is no passive filter device, the power factor of the AC system is 0.964. At this time, the reactive power component of the system can be balanced simply by using the reactive power distribution of the fan.

[0157] Furthermore, the PSDR transmission topology construction method for new energy power generation bases provided by this invention is characterized by eliminating low-order characteristic harmonics within each PSPT and reducing THD through equivalent reconstruction of the phase shift angle sequence, thereby reducing the impact of harmonic current surges on transformer equipment aging.

[0158] A PSPT-based PSDR topology simulation model was built in the MATLAB / Simulink environment according to the parameters in Table 1 to verify the above advantages.

[0159] Table 1. Topology parameters sent by PSDR

[0160]

[0161] Depend on Figure 9 It can be seen that the voltage and current waveforms of the PSDR output topology AC system have high sinusoidal characteristics and a small phase difference between voltage and current, which intuitively demonstrates the low harmonic distortion and high power factor characteristics of the PSDR output topology. Specifically, Figure 10 The table shows the spectral distribution of alternating current after Fast Fourier Transform (FFT) and the THD calculation results. It can be seen that harmonics are mainly distributed in the high-frequency band and have low content. THD i =0.14%), no additional filtering device is required; Figure 11 This reflects that when the system outputs 1.0 pu of active power, it generates 0.258 pu of reactive power. The calculated power factor PF=0.968 is close to the theoretically analyzed PF=0.964.

[0162] Depend on Figure 12 It can be seen that phase shift sequence reconstruction can eliminate low-frequency characteristic harmonics inside the PSPT and reduce the harmonic content (THD=21.68% before reconstruction, THD=6.77% after reconstruction), which is beneficial to improving the operating performance of the PSPT.

[0163] Megawatt-class deep-sea wind power transmission systems are one of the typical application scenarios for large-scale, long-distance new energy power generation bases. This invention implements the topology construction method using a 1000MW deep-sea wind power PSDR transmission system as an example. Figure 13 The overall structure and control scheme of the deep-sea wind power system are as follows: the turbine-side converter of the wind turbine adopts constant voltage control, the grid-side converter adopts grid-type control strategy, and the offshore AC grid exhibits voltage source characteristics; the receiving-end converter station adopts grid-following control strategy with constant DC bus voltage.

[0164] Specifically, the deep-sea wind power PSDR transmission topology is constructed using the PSPT provided in this invention, and is selected according to the harmonic requirements of the offshore AC power grid.M =12 and n =2, forming a PSDR output topology with 6 PSPT distributions; the phase shift angle sequence is equivalently reconstructed according to step S202, and Δ is calculated. θ =5°; PSPT is constructed using the primary winding phase-shifting method, calculated according to step S302. θ 1 = -27.5°; Finally, based on the rated PSPT capacity and voltage in step S4, take... S t =1200 MVA, U c =66 kV, U d =500 kV, calculated S PSPT =200 MVA, U p =66 kV, U s =30.85 kV, and take U o = U p =66 kV rating with different phase shift angles corresponding to U i and U e .

[0165] According to the PSDR transmission topology construction method provided by the present invention, a simulation model of a 1000MW deep-sea wind power PSDR transmission system was built in the MATLAB / Simulink environment. The main parameters of the system are shown in Table 2.

[0166] Table 2 Parameters of Deep-Sea Offshore Wind Power PSDR Transmission System

[0167]

[0168] Assuming the deep-sea wind farm has an independent starting power supply and is fully operational, from 0 to 1 second, the receiving-end converter station establishes the HVDC DC bus voltage, and the grid-side converter of the wind turbine is locked. At 1 second, the grid-side converter of the wind turbine starts, and the wind power is transmitted through the PSDR converter station. The waveform of the wind turbine's output power at this time is as follows: Figure 14 As shown, when the output active power is 1000 MW, the reactive power generated by the PSDR output topology is 350 MVar, and the power factor of the system is 0.944.

[0169] Voltage / current waveforms of deep-sea wind power AC systems are as follows: Figure 15As shown in the figure, it can be seen that without the installation of a filter device, the deep-sea wind power PSDR transmission system has stable operating capability, and the voltage and current waveforms of the AC system have extremely high sinusoidal characteristics. FFT analysis of the harmonic currents yields the following results: Figure 16 The harmonic spectrum shown indicates that the THD of the deep-sea wind power AC system using PSDR transmission topology remains at a very low level on both the PSDR AC side and the wind turbine port side.

[0170] In summary, the present invention provides a large-scale new energy diode phase-shifting rectification power transmission topology and method, which has application potential in actual new energy power generation and transmission scenarios. The PSPT-based topology construction method can meet the actual engineering needs, and achieves low harmonic distortion and high power factor effects that match the flexible direct transmission system without filtering devices while realizing large-scale, low-cost, and lightweight new energy transmission.

[0171] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for large-scale new energy diode phase-shifting rectification and power transmission, characterized in that, Includes the following steps: The multiplicity of the diode phase-shifting rectifier output topology is determined based on the AC side harmonics and DC side ripple requirements. The number of phase-shifting parallel transformer groups is determined based on the topological multiplicity of the diode phase-shifting rectifier output, and the equivalent reconstruction of the phase-shifting characteristics of the multi-winding is achieved through the equal arithmetic phase-shifting angle sequence. The phase shift angle of each phase-shifting parallel transformer group is controlled by a winding-extended connection method, and the DC sides of all diode rectifier units are connected in series to form a high-voltage output circuit, specifically: Phase shifting can be performed using either the secondary winding phase shifting method or the primary winding phase shifting method. The phase-shifting windings of the phase-shifting parallel transformer group adopt two symmetrical extension forms, namely reverse extension and forward extension, to achieve the control of the phase-shifting angle; When using the secondary winding phase-shifting method, there is N Build a PSPT M Each secondary winding undergoes phase shifting along its side, and the phases of the secondary windings satisfy the phase shift angle sequence; When using the primary winding phase-shifting method, there is N Build a PSPT N The primary windings undergo phase shifting along their sides, and all secondary windings are connected in a Y / d configuration to induce primary electromotive force. At this point, the phases of the secondary windings satisfy the phase shift angle sequence. The parallel phase-shifting transformer group adopts a symmetrical arrangement to reduce equipment design costs. The first term of this phase shift angle sequence... θ 1 represents the inverse phase shift angle, as detailed below: in, It is a multiplicity; The capacity and voltage parameters of the phase-shifting parallel transformer group are determined by combining the diode phase-shifting rectifier topology, the new energy power generation capacity, and the AC / DC system voltage level.

2. The method for large-scale new energy diode phase-shifting rectification and power transmission according to claim 1, characterized in that, The multiplicity of the diode phase-shift rectifier output topology is as follows: in, It is a multiple. It is a set of positive integers. The total harmonic distortion (THD) of the alternating current. The maximum allowable AC harmonics for actual system operation. This refers to the DC-side voltage ripple factor. This represents the maximum DC ripple.

3. The method for large-scale new energy diode phase-shifting rectification and power transmission according to claim 1, characterized in that, The number of phase-shifted parallel transformer groups is determined based on the topological multiplicity of the diode phase-shifted rectifier output, and the equivalent reconstruction of the multi-winding phase-shifting characteristics is achieved through an equal arithmetic phase-shifting angle sequence, specifically: Let the number of secondary windings of each phase-shifting parallel transformer group be... n , to obtain the distribution quantity ; The phase shift angle corresponding to the diode rectifier unit θ i Construct an arithmetic sequence and determine the common difference Δ of the arithmetic sequence. θ ; The phase shift angle difference between the secondary windings of the phase-shifted parallel transformer group is 60°. n ,when n When Δ = 2, the phase shift angle sequence is equivalently reconstructed to obtain Δ. θ .

4. The method for large-scale new energy diode phase-shifting rectification and power transmission according to claim 3, characterized in that, Distribution quantity for: in, It is a multiple.

5. The method for large-scale new energy diode phase-shifting rectification and power transmission according to claim 3, characterized in that, Tolerance Δ θ for: in, , For the 2nd i The phase shift angle corresponding to the diode rectifier unit For the 2nd i -1 Phase shift angle corresponding to the diode rectifier unit For the 2nd i +1 phase shift angle corresponding to the diode rectifier unit.

6. The method for large-scale new energy diode phase-shifting rectification and power transmission according to claim 1, characterized in that, When the secondary winding of the PSPT is in phase-shift mode, the output composite voltage is... U o = U s When the PSPT uses the primary winding phase-shifting method, the output composite voltage is... U o = U p The output synthesized voltage is based on the voltage ratings of the initial and extended windings, i.e.: in, This is the initial winding voltage after phase shift. For phase shift angle, This is the voltage of the phase-shifted extension winding.

7. A diode phase-shifting rectifier power output topology for a new energy power generation base, characterized in that, The large-scale new energy diode phase-shifting rectification power transmission method based on any one of claims 1 to 6 includes a phase-shifting parallel transformer group and a diode rectifier unit. The primary winding of the phase-shifting parallel transformer group is connected in parallel to the AC busbar, and the secondary winding is connected to the diode rectifier unit respectively. The DC side of the diode rectifier unit is connected in series in the order of phase shift angle sequence. For the secondary winding phase-shifting method, the primary winding adopts a Y-type connection, and the secondary windings adopt d-type phase-shifting connections, totaling... N Group of phase-shifting parallel transformers M Each secondary winding undergoes phase shifting along its side, and the phases of the secondary windings satisfy the phase shift angle sequence; For the primary winding phase-shifting method, the primary winding adopts a d-type phase-shifting connection, and the secondary winding adopts a Y / d-type connection to induce the primary electromotive force. There are a total of... N Group of phase-shifting parallel transformers N The primary winding undergoes phase shifting along its side, and the phase of the secondary winding satisfies the phase shift angle sequence.

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