Static and dynamic collaborative optimization design method for tether slow wave type dynamic cable

Abstract

The invention relates to a tether slow wave type dynamic cable static and dynamic collaborative optimization design method which comprises the following steps: determining an initial parameter optimization range of a variable, and randomly generating an initial population in the parameter optimization range; taking balance position static analysis and maximum offset position static analysis as targets, selecting a dynamic cable static configuration scheme meeting requirements, determining a dynamic configuration analysis variable parameter range according to a static configuration analysis result, and performing dynamic configuration analysis under a normal working condition and a limit working condition in sequence based on a decomposed multi-objective evolutionary algorithm; according to the method, a collaborative optimization framework of static configuration analysis and dynamic configuration analysis is established, so that coupling optimization of static configuration and dynamic response is realized. A staged optimization strategy is adopted, global parameter screening is carried out through a genetic algorithm, multi-target fine optimization is carried out through an MOEA / D algorithm, compared with a traditional single-stage design method, efficiency is greatly improved, and blind search in a traditional trial and error method is effectively avoided.

Description

Technical Field

[0001] The present invention relates to the field of marine engineering technology, and in particular to a static and dynamic collaborative optimization design method for a tethered slow-wave dynamic cable. Background Art

[0002] Dynamic cables are key components connecting floating offshore wind turbines to fixed submarine cables. They must withstand dynamic loads in the marine environment (such as waves, currents, and tides) while ensuring stable power transmission. Compared to static submarine cables, dynamic cables present technical challenges in flexible design, fatigue resistance, and long-term reliability. They are a crucial support for deep-sea wind power development.

[0003] In the prior art, the dynamic umbilical cable tether slow-wave configuration is usually taken as the object, and the relevant parameters are used as variables. The genetic algorithm is introduced to iteratively calculate the dynamic umbilical cable tether slow-wave configuration;

[0004] For example, the "FPSO dynamic duct and cable line intelligent optimization method, system and application" announced in patent announcement number CN116029216B takes the deep-water dynamic duct and cable tether slow-wave configuration to be optimized as the object, takes the effective tension, curvature, counterweight and buoyancy parameters as the optimization objective function, introduces the improved chaotic adaptive genetic algorithm, and uses the programming and nonlinear time-domain finite element software program to jointly simulate the control of the overall shape and local deformation of the duct and cable, and iteratively calculates the deep-water dynamic duct and cable tether slow-wave configuration that meets different sea conditions.

[0005] However, FPSO dynamic cables and offshore wind power dynamic cables are two different objects and have different working environments. FPSO dynamic cables are in ultra-deep water (1000-3000 meters) and move at low frequency and large amplitude. Their main optimization goal is pressure stability, and the algorithm converges in the direction of minimizing the extreme value of static stress. Offshore wind power dynamic cables are in deep water (50-200 meters, and a few projects reach 500 meters) and vibrate at high frequency and small amplitude. Their main optimization goal is fatigue life, and the algorithm converges in the direction of minimizing the dynamic fatigue damage rate. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the present invention provides a static and dynamic collaborative optimization design method for a tethered slow-wave dynamic cable to solve the above problems.

[0007] The present invention provides the following technical solutions:

[0008] A static and dynamic collaborative optimization design method for a tethered slow-wave dynamic cable comprises the following steps:

[0009] Determine the number, spacing, and initial positions of counterweights and buoyancy blocks, as well as the initial parameter optimization ranges for tether length, tether anchor point location, and tether-dynamic cable connection point location;

[0010] Generate the initial population randomly within the parameter optimization range based on the genetic algorithm;

[0011] Perform static analysis of the equilibrium position and the maximum offset position based on the generated parameters, and eliminate solutions that do not meet the static equilibrium requirements;

[0012] Static configuration analysis is performed with the minimum tension and maximum bending radius of the dynamic cable as the target optimization function;

[0013] In the static configuration analysis, based on the results of the static analysis at the equilibrium position and the static analysis at the maximum offset position, the dynamic cable scheme that does not meet the constraint conditions will be directly eliminated. If the constraint conditions are met, the next cycle will be entered until the cycle ends.

[0014] The solution set that meets the requirements obtained in the static configuration analysis is used. Each variable takes the minimum and maximum value of the dynamic cable solution in the solution set as the constraint range of the variable in the next step of dynamic configuration optimization.

[0015] Based on the decomposition of multi-objective evolutionary algorithm, dynamic configuration analysis is carried out under normal working conditions and extreme working conditions in turn. If the conditions are met, the output is given; if not, the iteration is returned.

[0016] Preferably, the genetic algorithm uses the second generation non-dominated sorting genetic algorithm NSGA-II algorithm.

[0017] Preferably, the numerical calculation and analysis software is called to batch set the relevant parameters of the dynamic cables to perform static analysis of the equilibrium position and the maximum offset position; the dynamic configuration analysis is performed by coupling the numerical calculation and analysis software with the decomposed multi-objective evolutionary algorithm.

[0018] Preferably, the objective optimization function in the static configuration analysis is:

[0019] f={min(T_max),max(min_bend-radius)}

[0020] Among them, T -max is the maximum tension of the dynamic cable, and min_bend-radius is the minimum bending radius of the dynamic cable.

[0021] Preferably, the constraints in the static configuration analysis are:

[0022] T -max <T allowable

[0023] Among them, T -max is the maximum tension of the dynamic cable, T allowable is the allowable tension;

[0024]

[0025] Where R is the bending radius during static configuration analysis;

[0026] F is the safety factor of the designed minimum bending radius;

[0027] MBR is the designed minimum bending radius of the dynamic cable;

[0028] x g +(n g -1)·d g <x b +(n b -1)·d b

[0029] n b >0

[0030] n g >0

[0031] Among them, x g is the initial position coordinate of the gravity block;

[0032] n g is the number of gravity blocks;

[0033] d g is the distance between the gravity blocks;

[0034] x b is the initial position coordinate of the buoyancy block;

[0035] n b is the number of buoyancy blocks;

[0036] d b is the spacing between the buoyancy blocks;

[0037] Except for the bottoming section, the rest of the dynamic cable cannot touch the bottom.

[0038]

[0039] Where:

[0040] s is the arc length parameter of the dynamic cable;

[0041] s contact is the position of the bottom point;

[0042] Z(s) is the vertical coordinate of the dynamic cable at position s;

[0043] x connection <x contact

[0044] Where: x connection is the horizontal coordinate of the connection between the tether and the dynamic cable;

[0045] x contact is the horizontal coordinate of the point where the dynamic cable touches the bottom;

[0046] Z connection >0

[0047] Where: Z connection is the vertical coordinate of the connection point between the tether and the dynamic cable;

[0048] T(ω)>0

[0049] ω∈Ω

[0050] Where: T(ω) is the tether tension;

[0051] ω is the environmental parameter;

[0052] Ω is the set of all allowed environmental parameters.

[0053] Preferably, R is the minimum value of the results of the near- and far-direction deviation of the floating offshore wind turbine, T -max Take the maximum value of the results of the near- and far-direction working conditions of the floating offshore wind turbine.

[0054] Preferably, each buoyancy block and each counterweight block are arranged at equal intervals.

[0055] Preferably, the objective optimization function of dynamic configuration analysis is:

[0056] Normal working conditions:

[0057] Number of buoyancy blocks: f2 = min(n b )

[0058] The number of counterweights: f3 = min(n g )

[0059] Among them, F max is the maximum tension of the dynamic cable;

[0060] n b is the number of buoyancy blocks;

[0061] n g is the number of counterweights;

[0062] r is the bending radius during dynamic configuration analysis.

[0063] Preferably, the constraints in the dynamic configuration analysis are the same as those in the static configuration analysis except for the minimum bending radius.

[0064] Preferably, the minimum bending radius constraint in the dynamic configuration analysis is:

[0065]

[0066] Wherein, MBR is the designed minimum bending radius of the dynamic cable;

[0067] R ac The minimum bending radius of the dynamic cable under extreme working conditions;

[0068] R lc The minimum bending radius of the dynamic cable under normal working conditions;

[0069] F is the safety factor of the designed minimum bending radius.

[0070] The present invention has the following beneficial technical effects:

[0071] This invention improves design efficiency through multi-dimensional collaborative optimization. By establishing a collaborative optimization framework for static and dynamic configuration analysis, it achieves coupled optimization of static configuration and dynamic response. A phased optimization strategy is employed, first using a genetic algorithm for global parameter screening, followed by multi-objective refinement using the MOEA / D algorithm. This significantly improves efficiency compared to traditional single-stage design methods, effectively avoiding the blind search inherent in traditional trial-and-error methods.

[0072] Incorporating normal and extreme operating conditions into dynamic configuration analysis, and employing a multi-condition verification mechanism for both normal and extreme conditions, dynamic cables can adapt to various sea conditions. A static analysis elimination mechanism based on maximum offset positions can proactively identify potential failure modes, ensuring that the bending radius of the dynamic cable remains above the critical value throughout its design life, thus preventing microbending fatigue damage.

[0073] The established "static screening-dynamic verification" dual-loop mechanism can greatly improve the elimination rate of invalid solutions and the utilization rate of computing resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 It is a flow chart of the present invention.

[0075] Figure 2 This is the offshore wind power dynamic cable of the present invention. DETAILED DESCRIPTION

[0076] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0077] Example:

[0078] A static and dynamic collaborative optimization design method for a tethered slow-wave dynamic cable comprises the following steps:

[0079] Step S1, determining that the dynamic cable configuration of the deep-sea floating offshore wind turbine is a tethered slow-wave type based on information such as water depth, environmental parameters, floating foundation, mooring system design results, and cable cross-sectional parameters;

[0080] Step S2: Based on design and construction experience and relevant technical standards and guidelines, determine the initial parameter optimization ranges for nine variables: the spacing, number, and initial positions of the counterweight blocks; the spacing, number, and initial positions of the buoyancy blocks; the tether length, tether anchor point location, and the location of the tether and dynamic cable connection point.

[0081] Step S3, using the second generation non-dominated sorting genetic algorithm NSGA-II to randomly generate an initial population within the parameter optimization range;

[0082] Step S4, calling numerical calculation and analysis software, setting relevant parameters of the dynamic cables in batches according to the generated plan and performing static analysis at the equilibrium position and static analysis at the maximum offset position;

[0083] Step S5, extract the maximum tension T of the dynamic cable in the numerical calculation analysis software -mac The solution that does not meet the static equilibrium is directly eliminated by taking into account the relevant parameter indicators such as the bending radius R. The objective function of the NSGA-II algorithm is set to f = {min(T_max), max(min_bend-radius)} and the constraints are set as follows:

[0084] ① Maximum dynamic cable tension T -max Lower than the allowable tension T allowable :

[0085] T -max <T allowable

[0086] ② The bending radius R during static configuration analysis is greater than the minimum design bending radius MBR of the dynamic cable:

[0087]

[0088] Where: F is the safety factor of the designed minimum bending radius;

[0089] MBR is the design minimum bending radius of the dynamic cable (m);

[0090] Among them, the bending radius R during static configuration analysis takes the minimum value of the results of the near-direction and far-direction offset conditions of the floating offshore wind turbine buoy, and the maximum tension takes the maximum value of the results of the near-direction and far-direction conditions of the floating offshore wind turbine buoy.

[0091] ③ Taking the position where the dynamic cable is connected to the buoy as the coordinate starting point, the coordinate of the position after the initial position of the gravity block + the number of gravity blocks * the spacing must be smaller than the coordinate of the position after the initial position of the buoyancy block + the number of buoyancy blocks * the spacing.

[0092] x g +(n g -1)·d g <x b +(n b -1)·d b

[0093] In the formula: Considering the installation problem of accessories during construction, the spacing between each buoyancy block and each counterweight block is equal.

[0094] x g is the initial position coordinate of the gravity block;

[0095] n g is the number of gravity blocks;

[0096] d g is the distance between the gravity blocks;

[0097] x b is the initial position coordinate of the buoyancy block;

[0098] n b is the number of buoyancy blocks;

[0099] d b is the spacing between the buoyancy blocks;

[0100] ④Except for the bottoming section, the rest of the dynamic cable cannot touch the bottom:

[0101]

[0102] Where:

[0103] s is the arc length parameter of the dynamic cable (the length of the curve along the cable path starting from the connection point with the float);

[0104] s contact is the position of the bottom point (corresponding to the first point where Z = 0);

[0105] Z(s) is the vertical coordinate of the dynamic cable at position s (Z = 0 on the seabed);

[0106] ⑤The horizontal coordinate of the connection point between the tether and the dynamic cable should be smaller than the horizontal coordinate of the point where the dynamic cable touches the bottom:

[0107] x xonnection <x contact

[0108] Where: xconnection is the abscissa (horizontal position) of the connection between the tether and the dynamic cable;

[0109] x contact is the abscissa of the bottom contact point of the dynamic cable (i.e. the horizontal position where the dynamic cable first touches the seabed);

[0110] ⑥ The connection point between the tether and the dynamic cable needs to be above the seabed:

[0111] Z connection >0

[0112] Where: Z connection is the vertical coordinate of the connection point between the tether and the dynamic cable (with the seabed as the reference plane Z = 0, and upward as the positive direction);

[0113] ⑦Tether tension T(ω) is greater than 0:

[0114] T(ω)>0

[0115] ω∈Ω

[0116] Where:

[0117] ω is the environmental parameter (such as wind speed, flow speed, direction, etc.);

[0118] Ω is the set of all allowed environmental parameters;

[0119] ⑧The number of buoyancy blocks is greater than 0, and the number of counterweight blocks is greater than 0;

[0120] n b >0

[0121] n g >0

[0122] Step S6: In the static configuration analysis, according to the results of the static analysis at the equilibrium position and the static analysis at the maximum offset position, the dynamic cable scheme that does not meet the constraint conditions is directly eliminated. If it meets the constraint conditions, the next cycle is entered until the cycle ends.

[0123] Step S7: For the solution set that meets the requirements obtained in the static configuration analysis, each variable takes the minimum and maximum values ​​of the dynamic cable solution in the solution set as the constraint range of the variable in the next step of dynamic configuration optimization.

[0124] Step S8, coupling the decomposition-based multi-objective evolutionary algorithm (MOEA / D) with numerical calculation and analysis software to initialize the population based on the appropriate variable range determined in step S7;

[0125] The objective function is set as:

[0126] Normal working conditions:

[0127]

[0128] Number of buoyancy blocks:

[0129] f2=min(n b )

[0130] Number of counterweights:

[0131] f3=min(n g )

[0132] Where:

[0133] F max is the maximum tension of the dynamic cable;

[0134] n b is the number of buoyancy blocks;

[0135] n g is the number of counterweights;

[0136] r is the bending radius during dynamic configuration analysis;

[0137] The constraints in dynamic configuration analysis are the same as those in static configuration analysis, except for the minimum bending radius.

[0138]

[0139] Where:

[0140] MBR is the design minimum bending radius of the dynamic cable, (m);

[0141] R ac is the minimum bending radius of the dynamic cable under extreme working conditions, (m);

[0142] R lc The minimum bending radius of the dynamic cable under normal (occasional) working conditions, (m);

[0143] F is the safety factor of the designed minimum bending radius.

[0144] The above-described embodiments merely represent specific implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A static and dynamic collaborative optimization design method for a tethered slow-wave dynamic cable, characterized in that: The following steps are involved: Determine the number, spacing, and initial positions of counterweights and buoyancy blocks, as well as the initial parameter optimization ranges for tether length, tether anchor point location, and tether-dynamic cable connection point location; Generate the initial population randomly within the parameter optimization range based on the genetic algorithm; Perform static analysis of the equilibrium position and the maximum offset position based on the generated parameters, and eliminate solutions that do not meet the static equilibrium requirements; Static configuration analysis is performed with the minimum tension and maximum bending radius of the dynamic cable as the target optimization function; In the static configuration analysis, based on the results of the static analysis at the equilibrium position and the static analysis at the maximum offset position, the dynamic cable scheme that does not meet the constraint conditions will be directly eliminated. If the constraint conditions are met, the next cycle will be entered until the cycle ends. The solution set that meets the requirements obtained in the static configuration analysis is used. Each variable takes the minimum and maximum value of the dynamic cable solution in the solution set as the constraint range of the variable in the next step of dynamic configuration optimization. Based on the decomposition of multi-objective evolutionary algorithm, dynamic configuration analysis is carried out under normal working conditions and extreme working conditions in turn. If the conditions are met, the output is given; if not, the iteration is returned.

2. The static and dynamic coordinated optimization design method of the tethered slow-wave dynamic cable according to claim 1 is characterized in that: The genetic algorithm uses the second generation non-dominated sorting genetic algorithm NSGA-II algorithm.

3. The static and dynamic coordinated optimization design method of a tethered slow-wave dynamic cable according to claim 1 is characterized in that: Call the numerical calculation and analysis software to batch set the relevant parameters of the dynamic cables to perform static analysis at the equilibrium position and static analysis at the maximum offset position; and perform dynamic configuration analysis by coupling the decomposed multi-objective evolutionary algorithm with the numerical calculation and analysis software.

4. The static and dynamic coordinated optimization design method of a tethered slow-wave dynamic cable according to claim 1 is characterized in that: The objective optimization function in static configuration analysis is: f={min(T_max),max(min_bend-radius)} Among them, T -max is the maximum tension of the dynamic cable, and min_bend-radius is the minimum bending radius of the dynamic cable.

5. The static and dynamic coordinated optimization design method of a tethered slow-wave dynamic cable according to claim 4 is characterized in that: The constraints in static configuration analysis are: T -max <T allowable Among them, T -max is the maximum tension of the dynamic cable, T allowable is the allowable tension; Where R is the bending radius during static configuration analysis; F is the safety factor of the designed minimum bending radius; MBR is the designed minimum bending radius of the dynamic cable; x g +(n g -1)·d g <x b +(n b -1)·d b n b >0 n g >0 Among them, x g is the initial position coordinate of the gravity block; n g is the number of gravity blocks; d g is the distance between the gravity blocks; x b is the initial position coordinate of the buoyancy block; n b is the number of buoyancy blocks; d b is the spacing between the buoyancy blocks; Except for the bottoming section, the rest of the dynamic cable cannot touch the bottom. Where: s is the arc length parameter of the dynamic cable; s contact is the position of the bottom point; Z(s) is the vertical coordinate of the dynamic cable at position s; x connection <x contact Where: x connection is the horizontal coordinate of the connection between the tether and the dynamic cable; x contact is the horizontal coordinate of the point where the dynamic cable touches the bottom; Z connection >0 Where: Z connection is the vertical coordinate of the connection point between the tether and the dynamic cable; T(ω)>0 ω∈Ω Where: T(ω) is the tether tension; ω is the environmental parameter; Ω is the set of all allowed environmental parameters.

6. The static and dynamic coordinated optimization design method for tethered slow-wave dynamic cables according to claim 5 is characterized in that: R is the minimum value of the results of the near-direction and far-direction deviation of the floating offshore wind turbine, T -max Take the maximum value of the results of the near- and far-direction working conditions of the floating offshore wind turbine.

7. The static and dynamic coordinated optimization design method of a tethered slow-wave dynamic cable according to claim 5 is characterized in that: Each buoyancy block and each counterweight block are arranged at equal intervals.

8. The static and dynamic coordinated optimization design method for a tethered slow-wave dynamic cable according to claim 1 is characterized in that: The objective optimization function of dynamic configuration analysis is: Normal working conditions: Number of buoyancy blocks: f2 = min(n b ) The number of counterweights: f3 = min(n g ) Among them, F max is the maximum tension of the dynamic cable; n b is the number of buoyancy blocks; n g is the number of counterweights; r is the bending radius during dynamic configuration analysis.

9. The static and dynamic coordinated optimization design method for tethered slow-wave dynamic cables according to claim 8, characterized in that: The constraints in dynamic configuration analysis are the same as those in static configuration analysis, except for the minimum bending radius.

10. The static and dynamic coordinated optimization design method of a tethered slow-wave dynamic cable according to claim 9, characterized in that: The minimum bending radius constraint in dynamic configuration analysis is: Wherein, MBR is the designed minimum bending radius of the dynamic cable; R ac The minimum bending radius of the dynamic cable under extreme working conditions; F is the safety factor of the designed minimum bending radius.

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