Multi-configuration method and device of diode phase shift rectification sending-out system

Abstract

The invention discloses a multiple configuration method and device for a diode phase-shift rectification sending-out system, and relates to the technical field of power electronics, and the method comprises the steps: obtaining a diode rectification unit topological graph and rectification working condition parameters of the diode phase-shift rectification sending-out system, and obtaining a diode rectification unit topological graph of the diode phase-shift rectification sending-out system according to the rectification working condition parameters and a preset power frequency period coefficient; determining the direct-current side output current of the diode rectification unit, carrying out harmonic characteristic analysis by adopting the direct-current side output current of the diode rectification unit and the topological graph of the diode rectification unit to obtain a total harmonic distortion rate function corresponding to the diode phase-shift rectification sending-out system, and calculating the harmonic distortion value of the diode phase-shift rectification sending-out system according to a preset harmonic distortion limit value and the total harmonic distortion rate function. And determining a target multiplicative number of the diode phase-shift rectification sending-out system. The technical problem that in the prior art, working condition parameters of a diode phase-shifting rectification sending-out system are not fully utilized to analyze multiple multiplications, and the reliability of an offshore sending-out platform is reduced is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to a multiple configuration method and system for a diode phase-shift rectification and transmission system. Background Art

[0002] At present, 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 the advantages of mature technology and rich engineering experience, the AC harmonics caused by the nonlinear transformation of the diode rectifier unit make the offshore transmission platform have problems such as large size and weight, high cost of power electronic devices, which restricts the large-scale application of offshore wind power. Therefore, it is crucial to balance the lightweight and economic efficiency of the offshore transmission platform.

[0003] The existing technology mainly achieves weight reduction and cost reduction of offshore delivery platforms by adopting technical solutions based on diode phase-shift rectification. However, the setting of the multiplexing number of diode phase-shift rectification often relies on manual experience or simple performance comparison, and does not fully utilize the operating parameters of the diode phase-shift rectification delivery system to analyze the multiplexing number, thereby reducing the reliability of the offshore delivery platform. Summary of the invention

[0004] The present invention provides a multiple configuration method and system for a diode phase-shift rectifier transmission system, which solves the technical problem that the prior art mainly achieves weight reduction and cost reduction of an offshore transmission platform by adopting a technical solution based on diode phase-shift rectifier, but the setting of the multiplexing number of diode phase-shift rectifier often relies on manual experience or simple performance comparison, and does not fully utilize the operating parameters of the diode phase-shift rectifier transmission system to analyze the multiplexing number, thereby reducing the reliability of the offshore transmission platform.

[0005] The present invention provides a multiple configuration method of a diode phase-shift rectification and transmission system, comprising:

[0006] Obtain the diode rectifier unit topology diagram and rectification operating parameters of the diode phase-shift rectifier transmission system;

[0007] Determining the DC side output current of the diode rectifier unit according to the rectification working condition parameters and the preset power frequency period coefficient;

[0008] The DC side output current of the diode rectifier unit and the topology diagram of the diode rectifier unit are used to perform harmonic characteristic analysis to obtain a total harmonic distortion rate function corresponding to the diode phase-shift rectifier transmission system;

[0009] According to the preset harmonic distortion limit and the total harmonic distortion rate function, the target multiplexing number of the diode phase-shift rectification and transmission system is determined.

[0010] Optionally, the rectification operating condition parameters include an AC side voltage effective value and a DC side load impedance, and the step of determining a DC side output current of a diode rectification unit according to the rectification operating condition parameters and a preset power frequency period coefficient includes:

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

[0012] The DC voltage average value is ratio-processed with the DC side load impedance to obtain a DC side output current of the diode rectifier unit.

[0013] Optionally, the step of performing 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 a total harmonic distortion rate function corresponding to the diode phase-shift rectifier transmission system includes:

[0014] Constructing a diode rectifier unit model using the diode rectifier unit topology diagram;

[0015] Inputting the DC side output current of the diode rectifier unit into the diode rectifier unit model to obtain a target diode rectifier unit model;

[0016] A phase-shift rectification test is performed using the target diode rectification unit model to obtain a three-phase line current waveform diagram on the AC side;

[0017] The harmonic characteristic analysis is performed 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-shift rectification and transmission system.

[0018] Optionally, the step of performing harmonic characteristic analysis on the AC side three-phase line current waveform diagram to obtain a total harmonic distortion rate function corresponding to the diode phase-shift rectification and transmission system includes:

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

[0020] Perform positive and negative sequence harmonic phase shift analysis on the primary current model of the phase-shifting transformer to obtain a fundamental current effective value function and a harmonic current effective value function;

[0021] The fundamental current effective value function, the wave current effective value function and a preset initial harmonic distortion rate function are coupled to obtain a total harmonic distortion rate function corresponding to the diode phase-shift rectification and transmission system.

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

[0023] Performing a time-domain Fourier analysis on the primary current model of the phase-shifting transformer based on preset positive and negative sequence harmonic phase-shifting characteristics to obtain a primary current model;

[0024] Inputting the preset harmonic components into the primary current model to obtain the target primary current model;

[0025] Performing harmonic component analysis on the target primary current model to obtain a fundamental current coefficient and a harmonic current coefficient;

[0026] The fundamental current coefficient and the harmonic current coefficient are respectively used to construct a fundamental current effective value function and a harmonic current effective value function.

[0027] Optionally, the step of determining a target multiplexing number of the diode phase-shift rectification and transmission system according to a preset harmonic distortion limit and the total harmonic distortion rate function comprises:

[0028] Inputting a preset initial multiplexing number into the total harmonic distortion function to obtain an initial total harmonic distortion;

[0029] Determining 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 value, the initial multiplexing multiplicity is added to a preset gradient threshold value to obtain a first sum value;

[0031] Using the first sum as a new initial multiplexing multiplicity, jumping to the step of inputting the preset initial multiplexing multiplicity into the total harmonic distortion function to obtain an initial total harmonic distortion, until the initial total harmonic distortion is less than the harmonic distortion limit;

[0032] If the initial total harmonic distortion rate is less than the harmonic distortion limit, the initial multiplexing number is used as the target multiplexing number of the diode phase-shift rectification and transmission system.

[0033] A second aspect of the present invention provides a multiple configuration device for a diode phase shift rectification and transmission system, comprising:

[0034] An acquisition module is used to obtain the diode rectification unit topology diagram and rectification operating condition parameters of the diode phase-shift rectification transmission system;

[0035] A first analysis module, used to determine the DC side output current of the diode rectifier unit according to the rectification working condition parameters and a preset power frequency period coefficient;

[0036] A 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 to obtain a total harmonic distortion rate function corresponding to the diode phase-shift rectifier transmission system;

[0037] A configuration module is used to determine the target multiplexing number of the diode phase-shift rectification and transmission system according to a preset harmonic distortion limit and the total harmonic distortion rate function.

[0038] A third aspect of the present invention provides an electronic device comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the multiple configuration method of the diode phase-shift rectifier transmission system as described in any one of the above items.

[0039] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the multiple configuration method of the diode phase-shift rectification and transmission system as described in any one of the above items.

[0040] A fifth aspect of the present invention provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer executes the multiple configuration method of the diode phase-shift rectifier transmission system as described in any one of the above items.

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

[0042] The present invention obtains the diode rectifier unit topology diagram and rectification operating parameters of the diode phase-shift rectifier transmission system, calculates the DC side output current of the diode rectifier unit according to the rectification operating parameters and the preset power frequency period coefficient, and then performs harmonic characteristic analysis on the diode phase-shift rectifier transmission system through the diode rectifier unit topology diagram and the DC side output current of the diode rectifier unit to obtain the corresponding total harmonic distortion rate function, and optimizes and solves the total harmonic distortion rate function under the preset harmonic distortion limit to obtain the target multiplexing number. Compared with the traditional multiplexing number configuration method, the present invention improves the reliability of the offshore transmission platform by fully utilizing the rectification operating parameters of the diode phase-shift rectifier transmission system to analyze the multiplexing number. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0044] Figure 1 A flowchart of the steps of a multiple configuration method of a diode phase-shift rectification and transmission system provided in the first embodiment of the present invention;

[0045] Figure 2 A flowchart of the steps of a multiple configuration method of a diode phase-shift rectification and transmission system provided in the second embodiment of the present invention;

[0046] Figure 3 A schematic diagram of the structure of a diode phase-shift rectification and transmission system provided in the second embodiment of the present invention;

[0047] Figure 4 A schematic diagram of the three-phase line current waveform on the AC side provided in the second embodiment of the present invention;

[0048] Figure 5 A schematic diagram of the change of total harmonic distortion rate provided in the second embodiment of the present invention;

[0049] Figure 6 A schematic diagram showing the change of the primary line current of the phase-shifting transformer with the multiplexing number provided in the second embodiment of the present invention;

[0050] Figure 7 A schematic diagram showing the comparison between the calculated value and the theoretical value of the total harmonic distortion rate provided in the second embodiment of the present invention;

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

[0052] Fig. 9 A topological structure diagram of a diode phase-shift rectification and transmission system provided in the second embodiment of the present invention;

[0053] Fig.10 A schematic diagram of a time domain waveform of a diode phase-shift rectification and transmission system simulation provided in the second embodiment of the present invention;

[0054] Fig.11 A schematic diagram of a simulation of a theoretical model of a twelve-diode phase-shift rectifier circuit provided in the second embodiment of the present invention;

[0055] Fig.12 A schematic diagram of a diode phase-shift rectification physical platform experiment provided in the second embodiment of the present invention;

[0056] Fig.13 This is a FFT spectrum diagram of the AC side current simulated by the diode phase-shift rectification and transmission system provided in the second embodiment of the present invention;

[0057] Fig.14 A schematic diagram of the structure of a diode phase-shift rectification hardware experimental platform provided in the second embodiment of the present invention;

[0058] Fig.15 A structural block diagram of a multiple configuration device of a diode phase-shift rectification and transmission system provided in the third embodiment of the present invention;

[0059] Fig.16 A structural block diagram of an electronic device provided in Embodiment 4 of the present invention;

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

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

[0062] The embodiments of the present invention provide a multiple configuration method and system for a diode phase-shift rectifier transmission system, which is used to solve the technical problem that the prior art mainly achieves weight reduction and cost reduction of an offshore transmission platform by adopting a technical solution based on diode phase-shift rectifier, but the setting of the multiplexing number of the diode phase-shift rectifier often relies on manual experience or simple performance comparison, and does not fully utilize the operating parameters of the diode phase-shift rectifier transmission system to analyze the multiplexing number, thereby reducing the reliability of the offshore transmission platform.

[0063] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] See also Figure 1 , Figure 1 A flowchart of the steps of a multiple configuration method of a diode phase-shift rectification and transmission system provided in the first embodiment of the present invention.

[0065] The present invention provides a multiple configuration method of a diode phase-shift rectification and transmission system, comprising:

[0066] Step 101, obtaining a diode rectification unit topology diagram and rectification operating condition parameters of a diode phase-shift rectification transmission system;

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

[0068] In the embodiment of the present invention, a topological diagram of a diode rectifier unit of a diode phase-shift rectifier transmission system is obtained, and rectification operating parameters of the diode phase-shift rectifier transmission system are collected through a measuring component.

[0069] Step 102: Determine the DC side output current of the diode rectifier unit according to the rectification working condition parameters and the preset power frequency period coefficient;

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

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

[0072]

[0073] in, is the DC side output current of the diode rectifier unit, is the average DC voltage, is the DC side load impedance, is the angular frequency, For time, is the effective value of the AC side line voltage.

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

[0075] In an embodiment of the present 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 a target diode rectifier unit model, a phase-shift rectification test is performed using the target diode rectifier unit model to obtain a three-phase line current waveform on the AC side of the diode rectifier unit, a harmonic characteristic analysis is performed on the three-phase line current waveform on the AC side of the diode rectifier unit, and a total harmonic distortion rate function corresponding to the diode phase-shift rectification transmission system is obtained.

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

[0077]

[0078] in, is the total harmonic distortion, is the effective value of harmonic current, is the effective value of the fundamental current, is the harmonic lag order, is the multiplicity.

[0079] Step 104: Determine the target multiplexing number of the diode phase-shift rectification transmission system according to the preset harmonic distortion limit and the total harmonic distortion rate function.

[0080] In an embodiment of the present invention, a configuration constraint condition is constructed according to a preset harmonic distortion limit value, and a total harmonic distortion rate function is solved under the configuration constraint condition to obtain a target multiplexing number of a diode phase-shifted rectification transmission system.

[0081] In an embodiment of the present invention, by obtaining the diode rectifier unit topology diagram and rectification operating parameters of the diode phase-shift rectifier transmission system, the DC side output current of the diode rectifier unit is calculated according to the rectification operating parameters and the preset power frequency period coefficient, and then the diode phase-shift rectifier transmission system is subjected to harmonic characteristic analysis through the diode rectifier unit topology diagram and the DC side output current of the diode rectifier unit to obtain the corresponding total harmonic distortion rate function, and the total harmonic distortion rate function is optimized and solved under the preset harmonic distortion limit to obtain the target multiplexing number. Compared with the traditional multiplexing number configuration method, the present invention improves the reliability of the offshore transmission platform by making full use of the rectification operating parameters of the diode phase-shift rectifier transmission system to analyze the multiplexing number.

[0082] See also Figure 2 , Figure 2 A flowchart of the steps of a multiple configuration method of a diode phase-shift rectification and transmission system provided in the second embodiment of the present invention.

[0083] The present invention provides a multiple configuration method of a diode phase-shift rectification and transmission system, comprising:

[0084] Step 201, obtaining a diode rectification unit topology diagram and rectification operating condition parameters of a diode phase-shift rectification transmission system;

[0085] In the embodiment of the present invention, the diode rectification unit topology diagram and rectification operating condition parameters of the diode phase-shift rectification transmission system are obtained through the acquisition component.

[0086] It should be noted that, see Figure 3 As shown in the figure, the diode phase-shift rectifier transmission system integrates the boost / commutation platform of the new energy collection system by connecting diode rectifier units in series, which can ensure that the offshore AC collection side operates under low harmonic conditions. By obtaining the diode rectifier unit topology diagram and rectification condition parameters of the diode phase-shift rectifier transmission system, the AC side harmonics of the diode phase-shift rectifier transmission system are analyzed.

[0087] Step 202: Determine the DC side output current of the diode rectifier unit according to the rectification working condition parameters and the preset power frequency period coefficient;

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

[0089] S11, multiplying the effective value of the AC side voltage by a preset power frequency period coefficient to obtain an average DC voltage value;

[0090] In the embodiment of the present invention, the product of the effective value of the AC side voltage and the preset power frequency period coefficient is calculated to obtain the average DC voltage value.

[0091] S12, performing ratio processing on the average value of the DC voltage and the DC side load impedance to obtain the DC side output current of the diode rectifier unit.

[0092] In the embodiment of the present invention, the ratio between the average value of the 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, constructing a diode rectifier unit model using a diode rectifier unit topology diagram;

[0094] In the embodiment of the present invention, various device parameters in the diode rectifier unit topology diagram are extracted, and a diode rectifier unit model is constructed according to the various device parameters.

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

[0096] In the embodiment of the present 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-shift rectification test using the target diode rectification unit model to obtain a three-phase line current waveform at the AC side;

[0098] In the embodiment of the present invention, a phase-shift rectification test is performed using a target diode rectification unit model to obtain an AC side three-phase line current waveform.

[0099] Step 206: Perform harmonic characteristic analysis on the AC side three-phase line current waveform to obtain a total harmonic distortion rate function corresponding to the diode phase-shift rectification transmission system.

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

[0101] S21, using Fourier series analysis method to perform harmonic extraction processing on the AC side three-phase line current waveform to obtain the primary current model of the phase-shifting transformer;

[0102] In the embodiment of the present invention, refer to Figure 4 As shown in the figure, when the diode rectifier unit performs phase-shift rectification, the three-phase line current on the AC side of the diode rectifier unit is as high as the output current on the DC side of the diode rectifier unit, and is 2π / 3 wide, with positive and negative alternating square waves. The zero current segment width between the positive and negative square waves is π / 3. Since the primary current of the phase-shifting transformer in the three-phase line current waveform on the AC side is symmetrical about the y-axis and the waveform is an even function, the preset Dirichlet condition is used to perform harmonic characteristic analysis on the three-phase line current waveform on the AC side 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 a period of T, it generally satisfies the Dirichlet condition, and its harmonic characteristics can be analyzed using the Fourier series.

[0104] The expression for non-sinusoidal variables is:

[0105]

[0106] Among them, ω1 is the fundamental angular frequency of the AC side current, A0 is the DC component of the Fourier series, A n is the DC component and cosine component of the Fourier series, B n is the Fourier series sinusoidal component, and n is the number of harmonics generated.

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

[0108]

[0109] in, is 0, and through trigonometric functions and difference product formulas we can get:

[0110]

[0111] Substitute the non-sinusoidal variable F(ω1t) into A0, A n , B n , then:

[0112]

[0113] In A n ≠2n, An≠3n, A nis not 0. That is, when A n When is a non-zero term, n=6k±1. When n=6k+1, ,when hour, , then the primary current model of the phase-shifting transformer can be obtained by Fourier expansion of the primary current of the phase-shifting transformer.

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

[0115]

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

[0117] S22, performing positive and negative sequence harmonic phase shift analysis on the primary current model of the phase-shifting transformer, and obtaining a fundamental current effective value function and a harmonic current effective value function;

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

[0119] S221, performing time-domain Fourier analysis on the primary current model of the phase-shifting transformer based on preset positive and negative sequence harmonic phase-shifting characteristics to obtain a primary current model;

[0120] The positive and negative sequence harmonic phase shift characteristics refer to the positive and negative sequence harmonic phase shift characteristic relationship of the phase shift transformer in the diode phase shift rectification transmission system.

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

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

[0123]

[0124] It should be noted that a single diode rectifier unit presents a positive sequence of 6k+1 times and a negative sequence Harmonic emission characteristics of the order of 100. Assuming that the transformation ratio of the primary and secondary windings of the phase-shifting transformer is w, the primary current of the phase-shifting transformer is the multiple superposition of the current components on the AC side of each diode rectifier unit after phase shifting. The phase shifting process is as follows: After the primary signal of the phase-shifting transformer is phase-shifted by the phase-shifting transformer, it is rectified into DC through the diode rectifier unit. Due to the harmonic emission characteristics of the diode rectifier unit, positive-sequence 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 the phase-shifting transformer is phase-shifted, 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 is the number of harmonics generated. The positive and negative sequence harmonics emitted by the secondary side of the phase-shifting transformer are fed back to the primary side through the phase-shifting transformer, and the phase shift characteristic relationship of the positive and negative sequence harmonics can be obtained as follows:

[0127]

[0128] S222, inputting the preset harmonic component into the primary current model to obtain a target primary current model;

[0129] In the embodiment of the present invention, a preset harmonic component (6k±1th order component) is input into the primary current model to obtain a 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 side current of the i-th group and the i+N-th group of diode rectifier units is 0, and the primary current of the phase-shifting transformer does not contain the 6k±1 harmonic components; if k=mM, the AC side harmonic components of each diode rectifier unit cannot cancel each other, and the primary current of the phase-shifting transformer contains 6k±1 components. For the diode phase-shifting rectifier topology with a multiplexing number of M, the primary current of the phase-shifting transformer only contains 6Mk±1 components, and the preset harmonic components are determined to be 6Mk±1 components.

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

[0132]

[0133] S223, performing harmonic component analysis processing on the target primary current model to obtain fundamental current coefficients and harmonic current coefficients;

[0134] In the embodiment of the present invention, harmonic component analysis processing is performed on the target primary current model to obtain the fundamental current coefficient and the harmonic current coefficient.

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

[0136] In the embodiment of the present invention, the fundamental current coefficient is used to construct the fundamental current effective value function, and the harmonic current coefficient is used to construct the harmonic current effective value function.

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

[0138]

[0139] The harmonic current effective value function is specifically:

[0140]

[0141] S23, coupling the fundamental current effective value function, the wave current effective value function and the preset initial harmonic distortion rate function to obtain the total harmonic distortion rate function corresponding to the diode phase-shift rectification transmission system.

[0142] In the embodiment of the present invention, the fundamental current effective value function, the wave current effective value function and the preset initial harmonic distortion rate function are combined to obtain the total harmonic distortion rate function corresponding to the diode phase-shift rectification transmission system.

[0143] Step 207: Determine the target multiplexing number of the diode phase-shift rectification and transmission system according to the preset harmonic distortion limit and the total harmonic distortion rate function.

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

[0145] S31, inputting the preset initial multiplexing number into the total harmonic distortion function to obtain the initial total harmonic distortion;

[0146] In the embodiment of the present invention, a preset initial multiplexing number (ie, 2) is input into the total harmonic distortion function to obtain an initial total harmonic distortion.

[0147] S32, determining whether the initial total harmonic distortion rate is less than a preset harmonic distortion limit;

[0148] The harmonic distortion limit refers to the total harmonic distortion rate of the diode phase-shifted rectifier transmission system that meets the basic operating requirements without a filter, and the value is 3%.

[0149] In the embodiment of the present 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, then summing the initial multiplexing multiplicity and the preset gradient threshold to obtain a first sum value;

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

[0152] S34, using the first sum as a new initial multiplexing multiplicity, jumping to execute the step of inputting the preset initial multiplexing multiplicity into the total harmonic distortion function to obtain an initial total harmonic distortion rate, until the initial total harmonic distortion rate is less than the harmonic distortion limit;

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

[0154] S35. If the initial total harmonic distortion rate is less than the harmonic distortion limit, the initial multiplexing number is used as the target multiplexing number of the diode phase-shift rectifier transmission system.

[0155] In the embodiment of the present invention, if the initial total harmonic distortion rate is less than 3%, the initial multiplexing factor is used as the target multiplexing factor of the diode phase-shifted rectification and output system.

[0156] In another embodiment, multiplexing multiplicity of 1-20 is sequentially input into the total harmonic distortion function, and the initial total harmonic distortion corresponding to the multiplexing multiplicity of 1-20 is obtained as shown in Table 1. The multiplexing multiplicity variation curve is plotted using the data in Table 1 as shown in Figure 5 As shown, THDi(M) increases with M.

[0157]

[0158] At this time, the target multiplexing number is 11, which means that the secondary side of the phase-shifting transformer corresponding to the diode phase-shifting rectifier transmission system should have at least 11 sets of phase-shifting windings. However, considering the symmetry of the windings and the manufacturing process of the transformer, the number of the forward phase-shifting windings of the phase-shifting transformer should be the same as the number of the reverse phase-shifting windings. The application of the phase-shifting transformer using 12 sets of secondary windings to form a 72-pulse (twelve-fold) diode phase-shifting rectifier is now relatively mature, and has lower technical difficulty and cost than the higher-fold diode phase-shifting rectifier. Therefore, the target multiplexing number is 12. That is, a twelve-fold diode phase-shifting rectifier topology is adopted.

[0159] It is worth mentioning that the theoretical model simulation of the diode phase-shift rectifier transmission system is built on the MATLAB / Simulink platform, and harmonic calculation is performed. Figure 6 As shown in the figure, the primary line current iab of the phase-shifting transformer of the diode phase-shifting rectifier circuit with M=1~20. The iab of the diode phase-shifting rectifier circuit with different multiplicity is analyzed by FFT, and the THD is calculated and compared with the theoretical calculated value of THD in Table 1. The results are shown in Figure 7 According to the above theoretical model simulation, a diode phase-shift rectification hardware experimental platform is built as shown in Fig.14 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 of the primary side of the phase-shifting transformer 1. For the constructed physical platform, the DC side voltage U dc , primary line voltage u of phase-shifting transformer 1ab and the primary line current i of the phase-shifting transformer ab like Figure 8 As shown. To further support the above conclusions, the harmonic analysis of the AC collection side is carried out by taking the simulation of a 1000MW deep-sea wind power diode phase-shifted rectification transmission system as an example. The offshore wind turbine adopts the active-voltage / reactive-frequency drooping grid control strategy, and the deep-sea wind power diode phase-shifted rectification transmission system adopts a 66kV power frequency 50Hz AC collection and a 1000kV diode phase-shifted rectification DC transmission scheme. The overall system topology is shown in Fig. 9 As shown in Table 2, a simulation model is built on the MATLAB / Simulink platform according to the simulation parameters.

[0160]

[0161] In the above system simulation environment, the voltage U dc , Phase-shifting transformer primary line voltage u ab and the primary line current i of the phase-shifting transformer ab The time domain waveform is as follows Fig.10 See Figure 11-13 As shown in the figure, the primary harmonic order of the phase-shifting transformer of the twelve-diode phase-shifting rectifier circuit should be 72k±1 (k=1,2,…), while the theoretical model simulation, physical platform and deep-sea wind power diode phase-shifting rectifier transmission system simulation i ab FFT analysis shows high-frequency harmonic components at 3550Hz, 3650Hz, 7150Hz, and 7250Hz. Theoretical model simulation of twelve-diode phase-shift rectifier circuit ab The THD is 2.51%, which is close to the theoretical calculated THD value corresponding to M=12 in Table 1, meets the operating conditions without a filter, and verifies the correctness of the theoretical calculation. The THD of the primary current of the physical platform phase-shifting transformer is 3.55%. Compared with the theoretical calculation, the main factors for the high THD of the current on the AC side of the physical platform can be attributed to: 1. The three-phase voltage source connected to the primary AC 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 and has a transient process with overlapping phase changes. 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 i abThe THD is 0.18%, which meets the filter-free operation conditions. This result is much lower than the theoretical calculated value, which is mainly due to the high-frequency harmonic attenuation characteristics of the AC submarine cable equivalent circuit impedance, but does not negate the relevant conclusions about harmonic analysis and multiple configuration in the article. Similarly, this harmonic attenuation characteristic is also applicable to the actual physical platform. Both simulation and physical platform experimental results verify the effectiveness of the multiple configuration method of the deep-sea wind power diode phase-shifted rectification transmission system.

[0162] In an embodiment of the present invention, by obtaining the diode rectifier unit topology diagram and rectification operating parameters of the diode phase-shift rectifier transmission system, the DC side output current of the diode rectifier unit is calculated according to the rectification operating parameters and the preset power frequency period coefficient, and then the diode phase-shift rectifier transmission system is subjected to harmonic characteristic analysis through the diode rectifier unit topology diagram and the DC side output current of the diode rectifier unit to obtain the corresponding total harmonic distortion rate function, and the total harmonic distortion rate function is optimized and solved under the preset harmonic distortion limit to obtain the target multiplexing number. Compared with the traditional multiplexing number configuration method, the present invention improves the reliability of the offshore transmission platform by making full use of the rectification operating parameters of the diode phase-shift rectifier transmission system to analyze the multiplexing number.

[0163] See also Fig.15 , Fig.15 This is a structural block diagram of a multiple configuration device of a diode phase-shift rectification and transmission system provided in Embodiment 3 of the present invention.

[0164] The present invention provides a multiple configuration device for a diode phase-shift rectification and transmission system, comprising:

[0165] The acquisition module 301 is used to obtain the diode rectification unit topology diagram and rectification operating parameters of the diode phase-shift rectification transmission system;

[0166] The first analysis module 302 is used to determine the DC side output current of the diode rectifier unit according to the rectification condition parameters and the preset power frequency period 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 to obtain a total harmonic distortion rate function corresponding to the diode phase-shift rectifier transmission system;

[0168] The configuration module 304 is used to determine the target multiplexing number of the diode phase-shift rectification transmission system according to the preset harmonic distortion limit and the total harmonic distortion rate function.

[0169] Furthermore, the rectification operating condition 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 average value submodule is used to multiply the AC side voltage effective value by a preset power frequency period coefficient to obtain the DC voltage average value;

[0171] The DC side output current submodule is used to perform ratio processing on the average value of the DC voltage and 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] A first construction submodule is used to construct a diode rectifier unit model using a diode rectifier unit topology diagram;

[0174] A 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 a target diode rectifier unit model;

[0175] The phase-shift rectifier module is used to perform a phase-shift rectifier test using a target diode rectifier unit model to obtain a three-phase line current waveform diagram on the AC side;

[0176] The harmonic characteristic analysis submodule is used to perform harmonic characteristic analysis on the three-phase line current waveform on the AC side to obtain the total harmonic distortion rate function corresponding to the diode phase-shift rectification transmission system.

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

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

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

[0180] The coupling unit is used to couple the fundamental current effective value function, the wave current effective value function and the preset initial harmonic distortion rate function to obtain the total harmonic distortion rate function corresponding to the diode phase-shift rectification transmission system.

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

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

[0183] The harmonic component analysis subunit is used to input the preset harmonic components into the primary current model to obtain the target primary current model;

[0184] Perform harmonic component analysis on the target primary current model to obtain fundamental current coefficients and harmonic current coefficients;

[0185] The subunit is constructed to construct a fundamental current effective value function and a harmonic current effective value function by using the fundamental current coefficient and the harmonic current coefficient respectively.

[0186] Furthermore, the configuration module 304 includes:

[0187] An input submodule, used for inputting a preset initial multiplexing number into a total harmonic distortion function to obtain an initial total harmonic distortion;

[0188] An analysis submodule, used to determine whether the initial total harmonic distortion rate is less than a preset harmonic distortion limit;

[0189] If the initial total harmonic distortion rate is greater than or equal to the harmonic distortion limit, the initial multiplexing number is added to the preset gradient threshold to obtain a first sum value;

[0190] A jump submodule is used for taking the first sum as a new initial multiplexing multiplicity, jumping to execute the step of inputting the preset initial multiplexing multiplicity into the total harmonic distortion function to obtain the initial total harmonic distortion, until the initial total harmonic distortion is less than the harmonic distortion limit;

[0191] If the initial total harmonic distortion rate is less than the harmonic distortion limit, the initial multiplexing number is used as the target multiplexing number of the diode phase-shift rectifier output system.

[0192] See also Fig.16 , Fig.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, wherein the memory 402 stores a computer program; when the computer program is executed by the processor 402, the processor 402 executes the multiple configuration method of the diode phase-shifted rectification transmission system according to any of the above embodiments.

[0194] The memory 401 may be an electronic memory such as a flash memory, an EEPROM (electrically erasable programmable read-only memory), an EPROM, a hard disk or a ROM. The memory 401 has a storage space 403 for a program code 413 for executing any method step in the above method. For example, the storage space 403 for the program code may include individual program codes 413 for implementing the various steps in the above method, respectively. These program codes may be read from or written to one or more computer program products. These computer program products include program code carriers such as a hard disk, a compact disk (CD), a memory card or a floppy disk. The program code may be compressed, for example, in an appropriate form. When these codes are run by a computing and processing device, the computing and processing device is caused to execute the various steps in the above-described method.

[0195] Embodiment 5 of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the multiple configuration method of the diode phase-shift rectification and transmission system as in any of the above embodiments is implemented.

[0196] Embodiment 6 of the present invention further provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer executes a multiple configuration method for a diode phase-shifted rectifier transmission system as in any of the above embodiments.

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

[0198] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

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

[0200] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0201] If the integrated unit is implemented in the form of 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. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[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 the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. 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 embodiments of the present invention.

Claims

1. A multiple configuration method of a diode phase-shift rectification transmission system, characterized in that: include: Obtain the diode rectifier unit topology diagram and rectification operating parameters of the diode phase-shift rectifier transmission system; Determining the DC side output current of the diode rectifier unit according to the rectification working condition parameters and the preset power frequency period coefficient; The DC side output current of the diode rectifier unit and the topology diagram of the diode rectifier unit are used to perform harmonic characteristic analysis to obtain a total harmonic distortion rate function corresponding to the diode phase-shift rectifier transmission system; According to the preset harmonic distortion limit and the total harmonic distortion rate function, the target multiplexing number of the diode phase-shift rectification and transmission system is determined.

2. The multiple configuration method of the diode phase shift rectification and transmission system according to claim 1, characterized in that: The rectification working condition parameters include an effective value of an AC side voltage and a DC side load impedance. The step of determining a DC side output current of a diode rectification unit according to the rectification working condition parameters and a preset power frequency period coefficient includes: The AC side voltage effective value is multiplied by the preset power frequency period coefficient to obtain a DC voltage average value; The DC voltage average value is ratio-processed with the DC side load impedance to obtain a DC side output current of the diode rectifier unit.

3. The multiple configuration method of the diode phase shift rectification and transmission system according to claim 1, characterized in that: The step of using the DC side output current of the diode rectifier unit and the topology diagram of the diode rectifier unit to perform harmonic characteristic analysis to obtain a total harmonic distortion rate function corresponding to the diode phase-shift rectifier transmission system includes: Constructing a diode rectifier unit model using the diode rectifier unit topology diagram; Inputting the DC side output current of the diode rectifier unit into the diode rectifier unit model to obtain a target diode rectifier unit model; A phase-shift rectification test is performed using the target diode rectification unit model to obtain a three-phase line current waveform diagram on the AC side; The harmonic characteristic analysis is performed 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-shift rectification and transmission system.

4. The multiple configuration method of the diode phase shift rectification and transmission system according to claim 3, characterized in that: The step of performing harmonic characteristic analysis on the AC side three-phase line current waveform diagram to obtain a total harmonic distortion rate function corresponding to the diode phase-shift rectification and transmission system includes: The harmonic extraction process is performed on the three-phase line current waveform diagram of the AC side by using the Fourier series analysis method to obtain the primary current model of the phase-shifting transformer; Perform positive and negative sequence harmonic phase shift analysis on the primary current model of the phase-shifting transformer to obtain a fundamental current effective value function and a harmonic current effective value function; The fundamental current effective value function, the wave current effective value function and a preset initial harmonic distortion rate function are coupled to obtain a total harmonic distortion rate function corresponding to the diode phase-shift rectification and transmission system.

5. The multiple configuration method of the diode phase shift rectification and transmission system according to claim 4, characterized in that: The step of performing positive and negative sequence harmonic phase shift analysis on the primary current model of the phase-shifting transformer to obtain a fundamental current effective value function and a harmonic current effective value function comprises: Performing a time-domain Fourier analysis on the primary current model of the phase-shifting transformer based on preset positive and negative sequence harmonic phase-shifting characteristics to obtain a primary current model; Inputting the preset harmonic components into the primary current model to obtain the target primary current model; Performing harmonic component analysis on the target primary current model to obtain fundamental current coefficients and harmonic current coefficients; The fundamental current coefficient and the harmonic current coefficient are respectively used to construct a fundamental current effective value function and a harmonic current effective value function.

6. The multiple configuration method of the diode phase shift rectification and transmission system according to claim 1, characterized in that: The step of determining the target multiplexing number of the diode phase-shift rectification and transmission system according to the preset harmonic distortion limit and the total harmonic distortion rate function comprises: Inputting a preset initial multiplexing number into the total harmonic distortion function to obtain an initial total harmonic distortion; Determining 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 value, the initial multiplexing multiplicity is added to a preset gradient threshold value to obtain a first sum value; Using the first sum as a new initial multiplexing multiplicity, jumping to the step of inputting the preset initial multiplexing multiplicity into the total harmonic distortion function to obtain an initial total harmonic distortion, until the initial total harmonic distortion is less than the harmonic distortion limit; If the initial total harmonic distortion rate is less than the harmonic distortion limit, the initial multiplexing number is used as the target multiplexing number of the diode phase-shift rectification and transmission system.

7. A multiple configuration device for a diode phase shift rectification and transmission system, characterized in that: include: An acquisition module is used to obtain the diode rectification unit topology diagram and rectification operating condition parameters of the diode phase-shift rectification transmission system; A first analysis module, used to determine the DC side output current of the diode rectifier unit according to the rectification working condition parameters and a preset power frequency period coefficient; A 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 to obtain a total harmonic distortion rate function corresponding to the diode phase-shift rectifier transmission system; A configuration module is used to determine the target multiplexing number of the diode phase-shift rectification and transmission system according to a preset harmonic distortion limit and the total harmonic distortion rate function.

8. An electronic device, characterized in that: It comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the multiple configuration method of the diode phase-shift rectification transmission system as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed, the multiple configuration method of the diode phase-shift rectification and transmission system as described in any one of claims 1-6 is implemented.

10. A computer program product, characterized in that The computer program product includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer executes the multiple configuration method of the diode phase-shift rectification transmission system as described in any one of claims 1-6.

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