A method and apparatus for multiplexing a diode phase-shifting rectifier output system

Abstract

This invention discloses a multiplexing configuration method and apparatus for a diode phase-shift rectifier power transmission system, relating to the field of power electronics technology. The method involves acquiring the topology diagram and rectification operating parameters of the diode rectifier unit in the diode phase-shift rectifier power transmission system. Based on the rectification operating parameters and a preset power frequency cycle coefficient, the DC-side output current of the diode rectifier unit is determined. Harmonic characteristic analysis is performed using the DC-side output current and the diode rectifier unit topology diagram to obtain the total harmonic distortion (THD) function corresponding to the diode phase-shift rectifier power transmission system. Based on preset harmonic distortion limits and the THD function, the target multiplexing number of the diode phase-shift rectifier power transmission system is determined. This invention solves the technical problem that existing technologies do not fully utilize the operating parameters of the diode phase-shift rectifier power transmission system to analyze the multiplexing number, thus reducing the reliability of offshore power transmission platforms.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a multiplexing configuration method and system for a diode phase-shifting rectifier output system. Background Technology

[0002] Currently, offshore wind power DC transmission mainly adopts deep-sea wind power diode rectification transmission technology. However, although deep-sea wind power diode rectification transmission has advantages such as mature technology and rich engineering experience, the AC harmonics caused by the nonlinear transformation of the diode rectifier unit result in problems such as large size and weight of the offshore transmission platform and high cost of power electronic devices, which restrict the large-scale application of offshore wind power. Therefore, it is crucial to simultaneously achieve lightweight and economical offshore transmission platforms.

[0003] Existing technologies mainly achieve weight reduction and cost reduction of offshore delivery platforms by adopting diode phase-shifting rectification technology. However, the setting of the multiplexing number of diode phase-shifting rectification often relies on manual experience or simple performance comparison, without fully utilizing the operating parameters of the diode phase-shifting rectification delivery system to analyze the multiplexing number, thus reducing the reliability of the offshore delivery platform. Summary of the Invention

[0004] This invention provides a multiplexing configuration method and system for a diode phase-shifting rectifier power transmission system. It solves the technical problem that existing technologies mainly achieve weight reduction and cost reduction of offshore power transmission platforms by adopting diode phase-shifting rectification-based technical solutions. However, the setting of the multiplexing number of diode phase-shifting rectifiers often relies on manual experience or simple performance comparisons, without fully utilizing the operating parameters of the diode phase-shifting rectifier power transmission system to analyze the multiplexing number, thus reducing the reliability of the offshore power transmission platform.

[0005] This invention provides a multiplexing configuration method for a diode phase-shifting rectifier output system, comprising:

[0006] Obtain the topology diagram and rectification operating parameters of the diode rectifier unit in the diode phase-shifting rectifier output system;

[0007] The DC-side output current of the diode rectifier unit is determined based on the rectification operating parameters and the preset power frequency cycle coefficient.

[0008] Harmonic characteristic analysis was performed using the DC-side output current of the diode rectifier unit and the topology diagram of the diode rectifier unit to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system;

[0009] The target multiplicity of the diode phase-shifting rectifier output system is determined based on the preset harmonic distortion limit and the total harmonic distortion rate function.

[0010] Optionally, the rectification operating parameters include the effective value of the AC side voltage and the DC side load impedance. The step of determining the DC side output current of the diode rectifier unit based on the rectification operating parameters and a preset power frequency cycle coefficient includes:

[0011] The effective value of the AC side voltage is multiplied by the preset power frequency cycle coefficient to obtain the average value of the DC voltage;

[0012] The DC-side output current of the diode rectifier unit is obtained by comparing the average DC voltage with the DC-side load impedance.

[0013] Optionally, the step of performing harmonic characteristic analysis using the DC-side output current of the diode rectifier unit and the topology of the diode rectifier unit to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system includes:

[0014] A diode rectifier unit model is constructed using the aforementioned diode rectifier unit topology diagram;

[0015] The DC-side output current of the diode rectifier unit is input into the diode rectifier unit model to obtain the target diode rectifier unit model;

[0016] A phase-shifting rectification experiment was conducted using the target diode rectifier unit model to obtain the three-phase line current waveforms on the AC side.

[0017] Harmonic characteristic analysis was performed on the three-phase line current waveforms on the AC side to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system.

[0018] Optionally, the step of performing harmonic characteristic analysis on the three-phase line current waveforms on the AC side to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system includes:

[0019] The harmonic extraction process of the three-phase line current waveform diagram on the AC side was performed using Fourier series analysis to obtain the primary current model of the phase-shifting transformer.

[0020] Positive and negative sequence harmonic phase-shifting analysis was performed on the primary current model of the phase-shifting transformer to obtain the effective value function of the fundamental current and the effective value function of the harmonic current.

[0021] The fundamental current RMS function, the wave current RMS function, and the preset initial harmonic distortion rate function are coupled to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectification output system.

[0022] Optionally, the step of performing positive and negative sequence harmonic phase-shifting analysis on the primary current model of the phase-shifting transformer to obtain the effective value function of the fundamental current and the effective value function of the harmonic current includes:

[0023] Based on the preset positive and negative sequence harmonic phase shift characteristics, the primary current model of the phase-shifting transformer is subjected to time-domain Fourier analysis to obtain the primary current model.

[0024] The preset harmonic components are input into the primary current model to obtain the target primary current model;

[0025] The target primary current model is subjected to harmonic component analysis to obtain the fundamental current coefficient and harmonic current coefficient.

[0026] The fundamental current effective value function and the harmonic current effective value function are constructed using the fundamental current coefficient and the harmonic current coefficient, respectively.

[0027] Optionally, the step of determining the target multiplexing multiplicity of the diode phase-shifting rectifier output system based on the preset harmonic distortion limit and the total harmonic distortion rate function includes:

[0028] The initial multiplicity of the preset multiplication factor is input into the total harmonic distortion rate function to obtain the initial total harmonic distortion rate;

[0029] Determine whether the initial total harmonic distortion rate is less than a preset harmonic distortion limit;

[0030] If the initial total harmonic distortion rate is greater than or equal to the harmonic distortion limit, the initial multiplicity is summed with the preset gradient threshold to obtain a first sum.

[0031] The first sum is used as a new initial multiplicity, and the process jumps to the step of inputting the preset initial multiplicity into the total harmonic distortion rate function to obtain the initial total harmonic distortion rate, until the initial total harmonic distortion rate is less than the harmonic distortion limit.

[0032] If the initial total harmonic distortion rate is less than the harmonic distortion limit, then the initial multiplexing number is taken as the target multiplexing number of the diode phase-shifting rectifier output system.

[0033] A second aspect of the present invention provides a multiplexing configuration device for a diode phase-shifting rectifier output system, comprising:

[0034] The acquisition module is used to obtain the diode rectifier unit topology and rectifier operating parameters of the diode phase-shifting rectifier output system;

[0035] The first analysis module is used to determine the DC-side output current of the diode rectifier unit based on the rectification operating parameters and the preset power frequency cycle coefficient.

[0036] The second analysis module is used to perform harmonic characteristic analysis using the DC-side output current of the diode rectifier unit and the topology diagram of the diode rectifier unit, and to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system.

[0037] The configuration module is used to determine the target multiplexing number of the diode phase-shifting rectifier output system based on the preset harmonic distortion limit and the total harmonic distortion rate function.

[0038] A third aspect of the present invention provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the multiplexing configuration method for the diode phase-shifting rectification output system as described in any of the preceding claims.

[0039] The fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, it implements the multiplexing configuration method of the diode phase-shifting rectifier output system as described in any of the preceding claims.

[0040] The fifth aspect of the present invention provides a computer program product, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, wherein, when the program instructions are executed by a computer, the computer performs the multiplexing configuration method of the diode phase-shifting rectifier output system as described in any of the preceding claims.

[0041] As can be seen from the above technical solutions, the present invention has the following advantages:

[0042] This invention obtains the topology diagram and rectification operating parameters of the diode rectifier unit in a diode phase-shift rectifier power transmission system. Based on the rectification operating parameters and a preset power frequency cycle coefficient, the DC-side output current of the diode rectifier unit is calculated. Then, harmonic characteristic analysis of the diode phase-shift rectifier power transmission system is performed using the diode rectifier unit topology diagram and the DC-side output current to obtain the corresponding total harmonic distortion (THD) function. The THD function is then optimized under a preset harmonic distortion limit to obtain the target multiplicity. Compared with traditional multiplicity configuration methods, this invention improves the reliability of offshore power transmission platforms by fully utilizing the rectification operating parameters of the diode phase-shift rectifier power transmission system for multiplicity analysis. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a flowchart illustrating the steps of a multiplexing configuration method for a diode phase-shifting rectifier output system provided in Embodiment 1 of the present invention.

[0045] Figure 2 This is a flowchart illustrating the steps of a multiplexing configuration method for a diode phase-shifting rectifier output system provided in Embodiment 2 of the present invention.

[0046] Figure 3 This is a schematic diagram of the diode phase-shifting rectification output system provided in Embodiment 2 of the present invention;

[0047] Figure 4 This is a schematic diagram of the AC three-phase line current waveform provided in Embodiment 2 of the present invention;

[0048] Figure 5 This is a schematic diagram of the total harmonic distortion rate variation provided in Embodiment 2 of the present invention;

[0049] Figure 6 This is a schematic diagram illustrating the variation of the primary current of the phase-shifting transformer with the multiplicity of the multiplexing, provided in Embodiment 2 of the present invention.

[0050] Figure 7 This is a schematic diagram comparing the calculated and theoretical values ​​of total harmonic distortion (THD) provided in Embodiment 2 of the present invention.

[0051] Figure 8 This is a schematic diagram showing the changes in DC side voltage, primary line voltage of the phase-shifting transformer, and primary line current of the phase-shifting transformer during the diode phase-shifting rectification process provided in Embodiment 2 of the present invention;

[0052] Figure 9 This is a topology diagram of the diode phase-shifting rectification output system provided in Embodiment 2 of the present invention;

[0053] Figure 10 This is a schematic diagram of the time-domain waveform of the diode phase-shifting rectification output system provided in Embodiment 2 of the present invention;

[0054] Figure 11 This is a simulation diagram of the theoretical model of the twelve-diode phase-shifting rectifier circuit provided in Embodiment 2 of the present invention;

[0055] Figure 12 This is a schematic diagram of the diode phase-shifting rectification physical platform experiment provided in Embodiment 2 of the present invention;

[0056] Figure 13 The AC side current FFT spectrum of the diode phase-shifting rectifier output system provided in Embodiment 2 of the present invention is shown.

[0057] Figure 14 This is a schematic diagram of the structure of the diode phase-shifting rectification hardware experimental platform provided in Embodiment 2 of the present invention;

[0058] Figure 15 This is a structural block diagram of a multiplexing configuration device for a diode phase-shifting rectifier output system provided in Embodiment 3 of the present invention;

[0059] Figure 16 This is a structural block diagram of an electronic device provided in Embodiment 4 of the present invention;

[0060] The meanings of the reference numerals in the attached figures are as follows:

[0061] 1. Phase-shifting transformer; 2. Diode rectifier unit; 3. Oscilloscope; 4. Load; 5. Three-phase voltage regulator. Detailed Implementation

[0062] This invention provides a multiplexing configuration method and system for a diode phase-shifting rectifier power transmission system. This addresses the technical problem that existing technologies primarily rely on diode phase-shifting rectification to reduce the weight and cost of offshore power transmission platforms. However, the multiplexing factor for diode phase-shifting rectification often depends on manual experience or simple performance comparisons, failing to fully utilize the operating parameters of the diode phase-shifting rectifier power transmission system to analyze the multiplexing factor, thus reducing the reliability of the offshore power transmission platform.

[0063] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0064] Please see Figure 1 , Figure 1 This is a flowchart illustrating the steps of a multiplexing configuration method for a diode phase-shifting rectifier output system provided in Embodiment 1 of the present invention.

[0065] This invention provides a multiplexing configuration method for a diode phase-shifting rectifier output system, comprising:

[0066] Step 101: Obtain the topology diagram and rectification operating parameters of the diode rectifier unit of the diode phase-shifting rectifier output system;

[0067] The rectifier operating parameters refer to the effective value of the AC side line voltage and the DC side load impedance of the diode phase-shift rectifier output system.

[0068] In this embodiment of the invention, a topology diagram of the diode rectifier unit of the diode phase-shift rectifier output system is obtained, and the rectifier operating parameters of the diode phase-shift rectifier output system are collected by a measurement component.

[0069] Step 102: Determine the DC-side output current of the diode rectifier unit based on the rectification operating parameters and the preset power frequency cycle coefficient;

[0070] In this embodiment of the invention, the rectification operating parameters and the preset power frequency cycle coefficient are input into the preset DC-side output current function to obtain the DC-side output current of the diode rectifier unit.

[0071] It should be noted that the DC-side output current function is as follows:

[0072]

[0073] in, This refers to the DC-side output current of the diode rectifier unit. This is the average value of the DC voltage. The DC-side load impedance is Angular frequency, For time, This is the effective value of the AC side line voltage.

[0074] Step 103: Perform harmonic characteristic analysis using the DC-side output current of the diode rectifier unit and the topology diagram of the diode rectifier unit to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system;

[0075] In this embodiment of the invention, a diode rectifier unit model is constructed using a diode rectifier unit topology diagram. The DC-side output current of the diode rectifier unit is input into the diode rectifier unit model to obtain the target diode rectifier unit model. A phase-shifting rectification experiment is performed using the target diode rectifier unit model to obtain the three-phase line current waveform diagram of the AC side of the diode rectifier unit. Harmonic characteristic analysis is performed on the three-phase line current waveform diagram of the AC side of the diode rectifier unit to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectification output system.

[0076] It should be noted that the total harmonic distortion rate function is specifically as follows:

[0077]

[0078] in, Total harmonic distortion (THD) This is the effective value of the harmonic current. This is the effective value of the fundamental current. For harmonic lag order, It is a multiplicative multiplicity.

[0079] Step 104: Determine the target multiplexing number of the diode phase-shifting rectifier output system based on the preset harmonic distortion limit and total harmonic distortion rate function.

[0080] In this embodiment of the invention, configuration constraints are constructed based on preset harmonic distortion limits, and the total harmonic distortion rate function is solved under the configuration constraints to obtain the target multiplicity of the diode phase-shifting rectifier output system.

[0081] In this embodiment of the invention, by acquiring the topology diagram and rectification operating parameters of the diode rectifier unit of the diode phase-shift rectifier power transmission system, the DC-side output current of the diode rectifier unit is calculated based on the rectification operating parameters and a preset power frequency period coefficient. Then, harmonic characteristic analysis is performed on the diode phase-shift rectifier power transmission system using the diode rectifier unit topology diagram and the DC-side output current of the diode rectifier unit to obtain the corresponding total harmonic distortion (THD) function. The THD function is then optimized under a preset harmonic distortion limit to obtain the target multiplicity. Compared with traditional multiplicity configuration methods, this invention improves the reliability of the offshore power transmission platform by fully utilizing the rectification operating parameters of the diode phase-shift rectifier power transmission system to analyze the multiplicity.

[0082] Please see Figure 2 , Figure 2 This is a flowchart illustrating the steps of a multiplexing configuration method for a diode phase-shifting rectifier output system provided in Embodiment 2 of the present invention.

[0083] This invention provides a multiplexing configuration method for a diode phase-shifting rectifier output system, comprising:

[0084] Step 201: Obtain the topology diagram and rectification operating parameters of the diode rectifier unit of the diode phase-shifting rectifier output system;

[0085] In this embodiment of the invention, the diode rectifier unit topology and rectifier operating parameters of the diode phase-shifting rectifier output system are obtained by the acquisition component.

[0086] It should be noted that, for reference Figure 3 As shown, the diode phase-shifting rectifier power transmission system integrates the boost / converter platform of the new energy aggregation system through series-connected diode rectifier units, ensuring low-harmonic operation on the offshore AC aggregation side. By obtaining the diode rectifier unit topology and rectification parameters of the diode phase-shifting rectifier power transmission system, the harmonics on the AC side of the system are analyzed.

[0087] Step 202: Determine the DC-side output current of the diode rectifier unit based on the rectification operating parameters and the preset power frequency cycle coefficient;

[0088] Furthermore, the rectification operating parameters include the effective value of the AC side voltage and the DC side load impedance. Step 202 includes the following sub-steps:

[0089] S11. Multiply the effective value of the AC side voltage by the preset power frequency cycle coefficient to obtain the average value of the DC voltage;

[0090] In this embodiment of the invention, the average value of the DC voltage is obtained by calculating the product between the effective value of the AC side voltage and the preset power frequency cycle coefficient.

[0091] S12. The average DC voltage is compared with the DC side load impedance to obtain the DC side output current of the diode rectifier unit.

[0092] In this embodiment of the invention, the ratio between the average DC voltage and the DC-side load impedance is calculated to obtain the DC-side output current of the diode rectifier unit.

[0093] Step 203: Construct a diode rectifier unit model using the diode rectifier unit topology diagram;

[0094] In this embodiment of the invention, the parameters of each device in the diode rectifier unit topology diagram are extracted, and a diode rectifier unit model is constructed based on the parameters of each device.

[0095] Step 204: Input the DC side output current of the diode rectifier unit into the diode rectifier unit model to obtain the target diode rectifier unit model;

[0096] In this embodiment of the invention, the model parameters of the diode rectifier unit model are adjusted according to the DC-side output current of the diode rectifier unit to obtain the target diode rectifier unit model.

[0097] Step 205: Perform a phase-shifting rectification test using the target diode rectifier unit model to obtain the three-phase line current waveforms on the AC side;

[0098] In this embodiment of the invention, a phase-shifting rectification test is conducted using a target diode rectifier unit model to obtain the three-phase line current waveforms on the AC side.

[0099] Step 206: Perform harmonic characteristic analysis on the three-phase line current waveform diagram on the AC side to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system.

[0100] Furthermore, step 206 includes the following sub-steps:

[0101] S21. The harmonic extraction process of the three-phase line current waveform diagram on the AC side is performed by Fourier series analysis to obtain the primary current model of the phase-shifting transformer.

[0102] In the embodiments of the present invention, see Figure 4 As shown, when the diode rectifier unit performs phase-shift rectification, the AC three-phase line current of the diode rectifier unit is equal to the DC output current of the diode rectifier unit, with a width of 2π / 3, and is a square wave with alternating positive and negative values. The zero-current segment between the positive and negative square waves has a width of π / 3. Since the primary current of the phase-shifting transformer is symmetrical about the y-axis in the AC three-phase line current waveform diagram, and the waveform is an even function, the harmonic characteristics of the AC three-phase line current waveform diagram are analyzed using the preset Dirichlet conditions to obtain the primary current model of the phase-shifting transformer.

[0103] It should be noted that for a non-sinusoidal variable F(ω1t) with period T, which generally satisfies the Dirichlet condition, Fourier series can be used to analyze its harmonic characteristics.

[0104] The expression for a non-sine variable is as follows:

[0105]

[0106] Where ω1 is the fundamental angular frequency of the AC side current, A0 is the DC component of the Fourier series, and A n For the DC component and cosine component of the Fourier series, B n denoted as the sinusoidal component of the Fourier series, and n represents the harmonic order generated.

[0107] because Figure 4 Medium current i a Symmetric about the y-axis, the waveform is an even function, therefore its Fourier series B n If A is 0, then A0 and A n for:

[0108]

[0109] in, The sum is 0, which can be obtained using the trigonometric function sum-to-product formula:

[0110]

[0111] Substituting the nonsine variable F(ω1t) into A0, A n B n Then we have:

[0112]

[0113] In A n In the case that A ≠ 2n and An ≠ 3n, nNot zero. That is, when A n When the term is non-zero, n = 6k ± 1. When n = 6k + 1, ,when hour, Then, by performing a Fourier expansion on the primary current of the phase-shifting transformer, we can obtain the primary current model of the phase-shifting transformer.

[0114] The specific model of the primary current of a phase-shifting transformer is as follows:

[0115]

[0116] in, This is the primary current of the phase-shifting transformer.

[0117] S22. Perform positive and negative sequence harmonic phase-shifting analysis on the primary current model of the phase-shifting transformer to obtain the effective value function of the fundamental current and the effective value function of the harmonic current.

[0118] Furthermore, S22 includes the following sub-steps:

[0119] S221. Based on the preset positive and negative sequence harmonic phase shift characteristics, perform time-domain Fourier analysis on the primary current model of the phase-shifting transformer to obtain the primary current model.

[0120] The positive and negative sequence harmonic phase shift characteristics refer to the relationship between the positive and negative sequence harmonic phase shift characteristics of the phase-shifting transformer in a diode phase-shifting rectifier power transmission system.

[0121] In this embodiment of the invention, a time-domain Fourier analysis is performed on the primary current model of the phase-shifting transformer based on a preset positive and negative sequence harmonic phase-shifting characteristic relationship to obtain the primary current model.

[0122] It should be noted that the primary current model is as follows:

[0123]

[0124] It should be noted that a single diode rectifier unit exhibits a positive sequence (6k+1) and a negative sequence (6k+1). The harmonic emission characteristics of the phase-shifting transformer. Assume the turns ratio of the primary and secondary windings of the phase-shifting transformer is w, and the primary current of the phase-shifting transformer is the superposition of multiple AC current components from each diode rectifier unit after phase shifting. The phase shifting process is as follows: After phase shifting by the phase-shifting transformer, the primary signal of the phase-shifting transformer is rectified into DC by the diode rectifier unit. Due to the harmonic emission characteristics of the diode rectifier unit, positive and negative sequence harmonics are generated on the secondary side of the phase-shifting transformer. Let the primary signal of the phase-shifting transformer be Acos(ω1t), after phase shifting by the phase-shifting transformer, the secondary signal of the phase-shifting transformer becomes... α is the phase shift angle. Due to the harmonic emission characteristics of the diode rectifier unit, the positive and negative sequence harmonics emitted by the secondary side of the phase-shifting transformer are:

[0125]

[0126] Where n represents the order of the generated harmonics. The positive and negative sequence harmonics emitted from the secondary side of the phase-shifting transformer are fed back to the primary side via the phase-shifting transformer, and the specific phase-shifting characteristic relationship of the positive and negative sequence harmonics can be obtained as follows:

[0127]

[0128] S222. Input the preset harmonic components into the primary current model to obtain the target primary current model;

[0129] In this embodiment of the invention, a preset harmonic component (6k±1th order component) is input into the primary current model to obtain the target primary current model.

[0130] It should be noted that if k ≠ mM (m = 1, 2, 3, ...), the sum of the harmonic components of the AC current of the i-th and i+N-th diode rectifier units is 0, and the primary current of the phase-shifting transformer does not contain a 6k±1 harmonic component. If k = mM, the harmonic components of the AC current of each diode rectifier unit cannot cancel each other out, and the primary current of the phase-shifting transformer contains a 6k±1 harmonic component. Therefore, for a diode phase-shifting rectifier topology with a multiplexing multiplicity of M, the primary current of the phase-shifting transformer contains only a 6Mk±1 harmonic component, so the preset harmonic component is determined to be the 6Mk±1 harmonic component.

[0131] It should be noted that the target primary current model is specifically as follows:

[0132]

[0133] S223. Perform harmonic component analysis on the target primary current model to obtain the fundamental current coefficient and harmonic current coefficient.

[0134] In this embodiment of the invention, the target primary current model is subjected to harmonic component analysis to obtain the fundamental current coefficient and harmonic current coefficient.

[0135] S224. Construct the effective value function of the fundamental current and the effective value function of the harmonic current using the fundamental current coefficient and the harmonic current coefficient respectively.

[0136] In this embodiment of the invention, the fundamental current effective value function is constructed using the basic current coefficient, and the harmonic current effective value function is constructed using the harmonic current coefficient.

[0137] It should be noted that the fundamental current RMS value function is specifically as follows:

[0138]

[0139] The specific function of the effective value of harmonic current is as follows:

[0140]

[0141] S23. Couple the fundamental current RMS function, the wave current RMS function, and the preset initial harmonic distortion rate function to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system.

[0142] In this embodiment of the invention, the fundamental current RMS function, the wave current RMS function, and the preset initial harmonic distortion rate function are combined to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system.

[0143] Step 207: Determine the target multiplexing number of the diode phase-shifting rectifier output system based on the preset harmonic distortion limit and total harmonic distortion rate function.

[0144] Furthermore, step 207 includes the following sub-steps:

[0145] S31. Input the preset initial multiplicity into the total harmonic distortion rate function to obtain the initial total harmonic distortion rate;

[0146] In this embodiment of the invention, a preset initial multiplicity (i.e., 2) is input into the total harmonic distortion rate function to obtain the initial total harmonic distortion rate.

[0147] S32. Determine whether the initial total harmonic distortion rate is less than the preset harmonic distortion limit.

[0148] The harmonic distortion limit refers to the total harmonic distortion rate of a diode phase-shifting rectifier power supply system to meet the basic operating requirements without a filter, and is set to 3%.

[0149] In this embodiment of the invention, it is determined whether the initial total harmonic distortion rate is less than 3%.

[0150] S33. If the initial total harmonic distortion rate is greater than or equal to the harmonic distortion limit, the initial multiplicity is summed with the preset gradient threshold to obtain the first sum.

[0151] In this embodiment of the invention, if the initial total harmonic distortion rate is greater than or equal to 3%, the initial multiplicity and the preset gradient threshold (i.e., 2) are calculated to obtain the first sum.

[0152] S34. Take the first sum as the new initial multiplicity, jump to execute the step of inputting the preset initial multiplicity into the total harmonic distortion rate function to obtain the initial total harmonic distortion rate, until the initial total harmonic distortion rate is less than the harmonic distortion limit.

[0153] In this embodiment of the invention, a first sum is selected as a new initial multiplicity, and the process jumps to the step of inputting the preset initial multiplicity into the total harmonic distortion rate function to obtain the initial total harmonic distortion rate until the initial total harmonic distortion rate is less than 3%.

[0154] S35. If the initial total harmonic distortion rate is less than the harmonic distortion limit, then the initial multiplexing multiplicity is taken as the target multiplexing multiplicity of the diode phase-shifting rectifier output system.

[0155] In this embodiment of the invention, if the initial total harmonic distortion rate is less than 3%, the initial multiplexing multiplicity is used as the target multiplexing multiplicity of the diode phase-shifting rectifier output system.

[0156] In another embodiment, the multiplicity numbers from 1 to 20 are sequentially input into the total harmonic distortion (THD) function to obtain the initial THD corresponding to the multiplicity numbers from 1 to 20, as shown in Table 1. The multiplicity number variation curves are plotted using the data in Table 1. Figure 5 As shown, THDi(M) increases with M.

[0157]

[0158] The target multiplexing number is 11, meaning the phase-shifting transformer corresponding to the diode phase-shifting rectification output system should have at least 11 phase-shifting windings on its secondary side. However, considering the symmetry of the windings and the transformer manufacturing process, the number of forward and reverse phase-shifting windings should be the same. The application of a 72-pulse (twelve-fold) diode phase-shifting rectification system using 12 secondary windings is already quite mature and has lower technical difficulty and cost compared to diode phase-shifting rectification with higher multiplexing numbers. Therefore, the target multiplexing number is set to 12, i.e., a twelve-fold diode phase-shifting rectification topology is adopted.

[0159] It is worth mentioning that a theoretical model of the diode phase-shifting rectifier output system was built and simulated on the MATLAB / Simulink platform, and harmonic calculations were performed. (See also...) Figure 6 As shown, the primary current iab of the phase-shifting transformer in a diode phase-shifting rectifier circuit with M=1~20 is given. FFT analysis was performed on iab for diode phase-shifting rectifier circuits with different weights to calculate the THD, and the results were compared with the theoretical THD values ​​in Table 1. Figure 7 As shown in the figure. Based on the aforementioned theoretical model simulation, a diode phase-shifting rectification hardware experimental platform was built as follows. Figure 14 As shown. The hardware experimental platform consists of a three-phase voltage regulator 5, a phase-shifting transformer 1, a diode rectifier unit 2, and a load 4. The voltage output from the secondary side of the three-phase voltage regulator 5 is used as the input voltage from the primary side of the phase-shifting transformer 1. For the constructed physical platform, the DC-side voltage U recorded by the oscilloscope 3 is... dc The primary line voltage u of phase-shifting transformer 1ab and the primary current i of the phase-shifting transformer ab like Figure 8 As shown. To further corroborate the above conclusions, a harmonic analysis of the AC collection side is performed using a simulation of a 1000MW deep-sea wind power diode phase-shifting rectifier power transmission system as an example. The offshore wind turbines adopt a droop grid control strategy based on active power-voltage / reactive power-frequency, and the deep-sea wind power diode phase-shifting rectifier power transmission system employs a 66kV 50Hz AC collection and a 1000kV diode phase-shifting rectifier DC power transmission scheme. The overall system topology is as follows. Figure 9 As shown in Table 2, a simulation model was built on the MATLAB / Simulink platform based on the simulation parameters.

[0160]

[0161] Under the above system simulation environment, the DC side voltage U dc Phase-shifting transformer primary line voltage u ab and the primary current i of the phase-shifting transformer ab The time-domain waveform is as follows Figure 10 As shown. See also Figures 11-13 As shown, the primary harmonic order of the phase-shifting transformer in the twelve-diode phase-shifting rectifier circuit should be 72k±1 (k=1,2,…). However, the harmonic order of the phase-shifting transformer in the theoretical model simulation, physical platform simulation, and deep-sea wind power diode phase-shifting rectifier power transmission system simulation is different. ab FFT analysis revealed high-frequency harmonic components at 3550Hz, 3650Hz, 7150Hz, and 7250Hz. Simulation of the theoretical model of the twelve-diode phase-shifting rectifier circuit. ab The THD is 2.51%, which is close to the theoretical THD calculated for M=12 in Table 1, satisfying the filter-free operation conditions and verifying the correctness of the theoretical calculation. The THD of the primary current of the phase-shifting transformer on the physical platform is 3.55%. Compared with the theoretical calculation, the main factors for the higher THD of the AC current on the physical platform can be attributed to: 1. The three-phase voltage source connected to the AC side of the primary side of the phase-shifting transformer is not ideal, and the output three-phase AC voltage itself contains harmonics. 2. The diode rectifier unit is not ideal, exhibiting a transient process of commutation overlap. Compared with a single diode rectifier unit, the diode phase-shifting rectifier circuit in actual operation has significantly reduced the harmonic content on the AC side, and the error in the physical platform experiment is within an acceptable range. Simulation of Deep-Sea Wind Power Diode Phase-Shifting Rectifier Transmission System abThe THD is 0.18%, meeting the filterless operation requirements. This result is significantly lower than the theoretical calculation value, mainly due to the high-frequency harmonic attenuation characteristics of the equivalent circuit impedance of the AC submarine cable, but it does not negate the conclusions regarding harmonic analysis and multiplexing configuration presented in this paper. Similarly, this harmonic attenuation characteristic is also applicable to the actual physical platform. Simulation and physical platform experimental results both verify the effectiveness of the multiplexing configuration method for this deep-sea wind power diode phase-shifting rectifier power transmission system.

[0162] In this embodiment of the invention, by acquiring the topology diagram and rectification operating parameters of the diode rectifier unit of the diode phase-shift rectifier power transmission system, the DC-side output current of the diode rectifier unit is calculated based on the rectification operating parameters and a preset power frequency period coefficient. Then, harmonic characteristic analysis is performed on the diode phase-shift rectifier power transmission system using the diode rectifier unit topology diagram and the DC-side output current of the diode rectifier unit to obtain the corresponding total harmonic distortion (THD) function. The THD function is then optimized under a preset harmonic distortion limit to obtain the target multiplicity. Compared with traditional multiplicity configuration methods, this invention improves the reliability of the offshore power transmission platform by fully utilizing the rectification operating parameters of the diode phase-shift rectifier power transmission system to analyze the multiplicity.

[0163] Please see Figure 15 , Figure 15 This is a structural block diagram of a multiplexing configuration device for a diode phase-shifting rectifier output system provided in Embodiment 3 of the present invention.

[0164] The present invention provides a multiplexing configuration device for a diode phase-shifting rectifier output system, comprising:

[0165] The acquisition module 301 is used to acquire the topology diagram of the diode rectifier unit and the rectification operating parameters of the diode phase-shifting rectifier output system;

[0166] The first analysis module 302 is used to determine the DC-side output current of the diode rectifier unit based on the rectifier operating parameters and the preset power frequency cycle coefficient.

[0167] The second analysis module 303 is used to perform harmonic characteristic analysis using the DC side output current of the diode rectifier unit and the topology diagram of the diode rectifier unit, and to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system.

[0168] Configuration module 304 is used to determine the target multiplexing number of the diode phase-shifting rectifier output system based on the preset harmonic distortion limit and total harmonic distortion rate function.

[0169] Furthermore, the rectifier operating parameters include the effective value of the AC side voltage and the DC side load impedance. The first analysis module 302 includes:

[0170] The DC voltage averaging submodule is used to multiply the effective value of the AC side voltage by a preset power frequency cycle coefficient to obtain the average DC voltage.

[0171] The DC-side output current submodule is used to process the ratio of the average DC voltage to the DC-side load impedance to obtain the DC-side output current of the diode rectifier unit.

[0172] Furthermore, the second analysis module 303 includes:

[0173] The first construction submodule is used to construct a diode rectifier unit model using a diode rectifier unit topology diagram;

[0174] The second construction submodule is used to input the DC side output current of the diode rectifier unit into the diode rectifier unit model to obtain the target diode rectifier unit model;

[0175] The phase-shifting rectifier submodule is used to conduct phase-shifting rectification experiments using a target diode rectifier unit model to obtain the three-phase line current waveforms on the AC side.

[0176] The harmonic characteristic analysis submodule is used to perform harmonic characteristic analysis on the three-phase line current waveform diagram of the AC side, and obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system.

[0177] Furthermore, the harmonic characteristic analysis submodule includes:

[0178] The Fourier series analysis unit is used to perform harmonic extraction processing on the three-phase line current waveform diagram of the AC side using the Fourier series analysis method to obtain the primary current model of the phase-shifting transformer.

[0179] The positive and negative sequence harmonic analysis unit is used to perform positive and negative sequence harmonic phase-shifting analysis on the primary current model of the phase-shifting transformer to obtain the effective value function of the fundamental current and the effective value function of the harmonic current.

[0180] The coupling unit is used to couple the fundamental current RMS function, the wave current RMS function, and the preset initial harmonic distortion rate function to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system.

[0181] Furthermore, the positive and negative sequence harmonic analysis unit includes:

[0182] The time-series Fourier analysis subunit is used to perform time-domain Fourier analysis on the primary current model of the phase-shifting transformer based on the preset positive and negative sequence harmonic phase-shifting characteristics, so as to obtain the primary current model.

[0183] The harmonic component analysis sub-unit is used to input the preset harmonic components into the primary current model to obtain the target primary current model.

[0184] The target primary current model is subjected to harmonic component analysis to obtain the fundamental current coefficient and harmonic current coefficient.

[0185] Construct sub-units to build the effective value function of the fundamental current and the effective value function of the harmonic current using the fundamental current coefficient and the harmonic current coefficient, respectively.

[0186] Furthermore, configuration module 304 includes:

[0187] The input submodule is used to input the preset initial multiplicity into the total harmonic distortion rate function to obtain the initial total harmonic distortion rate;

[0188] The analysis submodule is used to determine whether the initial total harmonic distortion rate is less than the preset harmonic distortion limit.

[0189] If the initial total harmonic distortion rate is greater than or equal to the harmonic distortion limit, the initial multiplicity is summed with the preset gradient threshold to obtain the first sum.

[0190] The jump-rotor module is used to take the first sum as a new initial multiplicity and jump to execute the step of inputting the preset initial multiplicity into the total harmonic distortion rate function to obtain the initial total harmonic distortion rate, until the initial total harmonic distortion rate is less than the harmonic distortion limit.

[0191] If the initial total harmonic distortion rate is less than the harmonic distortion limit, then the initial multiplexing multiplicity is taken as the target multiplexing multiplicity of the diode phase-shifting rectifier output system.

[0192] Please see Figure 16 , Figure 16 This is a structural block diagram of an electronic device provided in Embodiment 4 of the present invention.

[0193] An electronic device according to an embodiment of the present invention includes: a memory 401 and a processor 402. The memory 402 stores a computer program. When the computer program is executed by the processor 402, the processor 402 executes the multiplexing configuration method of the diode phase-shifting rectification output system as described in any of the above embodiments.

[0194] Memory 401 may be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Memory 401 has storage space 403 for program code 413 for performing any of the method steps described above. For example, storage space 403 for program code may include individual program codes 413 for implementing the various steps in the methods described above. This program code may be read from or written to one or more computer program products. These computer program products include program code carriers such as hard disks, compact discs (CDs), memory cards, or floppy disks. The program code may be compressed, for example, in a suitable form. When run by a computing processing device, this code causes the computing processing device to perform the various steps in the methods described above.

[0195] Embodiment 5 of the present invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the multiplexing configuration method of the diode phase-shifting rectifier output system as described in any of the above embodiments.

[0196] Embodiment 6 of the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer performs a multiplexing configuration method for a diode phase-shifting rectifier output system as described in any of the above embodiments.

[0197] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0198] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0199] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0200] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0201] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0202] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for multiplexing configuration of a diode phase-shifting rectifier output system, characterized in that, include: Obtain the topology diagram and rectification operating parameters of the diode rectifier unit in the diode phase-shifting rectifier output system; The DC-side output current of the diode rectifier unit is determined based on the rectification operating parameters and the preset power frequency cycle coefficient. Harmonic characteristic analysis was performed using the DC-side output current of the diode rectifier unit and the topology diagram of the diode rectifier unit to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system; The target multiplicity of the diode phase-shifting rectifier output system is determined based on the preset harmonic distortion limit and the total harmonic distortion rate function. The step of performing harmonic characteristic analysis using the DC-side output current of the diode rectifier unit and the topology of the diode rectifier unit to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system includes: A diode rectifier unit model is constructed using the aforementioned diode rectifier unit topology diagram; The DC-side output current of the diode rectifier unit is input into the diode rectifier unit model to obtain the target diode rectifier unit model; A phase-shifting rectification experiment was conducted using the target diode rectifier unit model to obtain the three-phase line current waveforms on the AC side. Harmonic characteristic analysis was performed on the three-phase line current waveforms on the AC side to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system. The step of determining the target multiplexing multiplicity of the diode phase-shifting rectifier output system based on the preset harmonic distortion limit and the total harmonic distortion rate function includes: The initial multiplicity of the preset multiplication factor is input into the total harmonic distortion rate function to obtain the initial total harmonic distortion rate; Determine whether the initial total harmonic distortion rate is less than a preset harmonic distortion limit; If the initial total harmonic distortion rate is greater than or equal to the harmonic distortion limit, the initial multiplicity is summed with the preset gradient threshold to obtain a first sum. The first sum is used as a new initial multiplicity, and the process jumps to the step of inputting the preset initial multiplicity into the total harmonic distortion rate function to obtain the initial total harmonic distortion rate, until the initial total harmonic distortion rate is less than the harmonic distortion limit. If the initial total harmonic distortion rate is less than the harmonic distortion limit, then the initial multiplexing number is taken as the target multiplexing number of the diode phase-shifting rectifier output system.

2. The multiplexing configuration method for the diode phase-shifting rectifier output system according to claim 1, characterized in that, The rectification operating parameters include the effective value of the AC side voltage and the DC side load impedance. The step of determining the DC side output current of the diode rectifier unit based on the rectification operating parameters and the preset power frequency cycle coefficient includes: The effective value of the AC side voltage is multiplied by the preset power frequency cycle coefficient to obtain the average value of the DC voltage; The DC-side output current of the diode rectifier unit is obtained by comparing the average DC voltage with the DC-side load impedance.

3. The multiplexing configuration method for the diode phase-shifting rectifier output system according to claim 1, characterized in that, The step of performing harmonic characteristic analysis on the three-phase line current waveform of the AC side to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system includes: The harmonic extraction process of the three-phase line current waveform diagram on the AC side was performed using Fourier series analysis to obtain the primary current model of the phase-shifting transformer. Positive and negative sequence harmonic phase-shifting analysis was performed on the primary current model of the phase-shifting transformer to obtain the effective value function of the fundamental current and the effective value function of the harmonic current. The fundamental current RMS function, the wave current RMS function, and the preset initial harmonic distortion rate function are coupled to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectification output system.

4. The multiplexing configuration method for the diode phase-shifting rectifier output system according to claim 3, characterized in that, The step of performing positive and negative sequence harmonic phase-shifting analysis on the primary current model of the phase-shifting transformer to obtain the effective value function of the fundamental current and the effective value function of the harmonic current includes: Based on the preset positive and negative sequence harmonic phase shift characteristics, the primary current model of the phase-shifting transformer is subjected to time-domain Fourier analysis to obtain the primary current model. The preset harmonic components are input into the primary current model to obtain the target primary current model; The target primary current model is subjected to harmonic component analysis to obtain the fundamental current coefficient and harmonic current coefficient. The fundamental current effective value function and the harmonic current effective value function are constructed using the fundamental current coefficient and the harmonic current coefficient, respectively.

5. A multiplexing configuration device for a diode phase-shifting rectifier output system, used to implement the multiplexing configuration method for the diode phase-shifting rectifier output system according to any one of claims 1-4, characterized in that, include: The acquisition module is used to obtain the diode rectifier unit topology and rectifier operating parameters of the diode phase-shifting rectifier output system; The first analysis module is used to determine the DC-side output current of the diode rectifier unit based on the rectification operating parameters and the preset power frequency cycle coefficient. The second analysis module is used to perform harmonic characteristic analysis using the DC-side output current of the diode rectifier unit and the topology diagram of the diode rectifier unit, and to obtain the total harmonic distortion rate function corresponding to the diode phase-shifting rectifier output system. The configuration module is used to determine the target multiplexing number of the diode phase-shifting rectifier output system based on the preset harmonic distortion limit and the total harmonic distortion rate function.

6. An electronic device, characterized in that, The system includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor causes the processor to perform the steps of the multiplexing configuration method for the diode phase-shifting rectifier output system as described in any one of claims 1-4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed, it implements the multiplexing configuration method of the diode phase-shifting rectifier output system as described in any one of claims 1-4.

8. A computer program product, characterized in that, The computer program product includes a computer program stored on a non-transitory computer-readable storage medium, the computer program including program instructions, wherein when the program instructions are executed by a computer, the computer performs the multiplexing configuration method of the diode phase-shifting rectifier output system as described in any one of claims 1-4.

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