Time-domain Model Research Articles

WECs microarray effect on the coupled dynamic response and power performance of a floating combined wind and wave energy system

With numerous floating wind-wave hybrid system concepts proposed and studied on a large scale, multiple wave energy converters (WECs) are usually integrated in a hybrid system to spread the cost and obtain more power. The internal interactions between WECs and a platform are complex and difficult to assess. The effect of WECs microarray on the performance and interaction of hybrid systems has not been adequately studied. To bridge this gap, the frequency-domain and time-domain modelling considering the effect of WECs microarray is first established using the coupled AQWA-FAST simulation system. On this basis, this work studies the internal connection between the layout of the WECs, and interaction factors for hydrodynamic coupling between WECs microarrays and the platform. The relationship between the WECs microarray and the aerodynamic response of the wind turbine is analysed, as well as the relationship between the microarray layout and the disturbed wave field of the devices. Results show that the WECs outer microarray performs better in terms of pitch motion suppression and power output, while the inner microarray exerts a more positive influence on the dynamic response of the tower.

Difference between Charge–Voltage Relations of Ordinary and Fractional Capacitors

In an ordinary time-varying capacitor, there is debate on whether a time-domain multiplication or a time-domain convolution of capacitance and voltage determines charge. The objective of this work is to resolve this question by experiments on a time-varying capacitor in parallel with a resistor. It was implemented by a motor-driven potentiometer and op-amps. The response matched a power-law function over about two decades of time, and not an exponential, for several sets of parameters. This confirms the time-domain multiplication model. This result is the opposite of that obtained for a constant phase element (CPE) in its common time- and frequency-varying capacitor interpretation. This demonstrates that a CPE is fundamentally different from an ordinary time- and frequency-varying capacitor.

Fast time-domain model for the preliminary design of a wave power farm

This study presents a novel, fast time-domain model developed for an array of interacting point-absorber wave energy converters. The model is validated using experimental wave tank data. The point-absorbers, based on Uppsala University’s design, are arranged in a symmetric grid and interact with scattered and radiated waves while constrained to the heave motion. The model employs linear potential flow theory to solve the hydrodynamic coefficients in the frequency domain and employs Cummins’ formulation to solve the equations of motion in the time domain. Modeling an array of wave energy converters in the time domain yields a system of integro-differential equations, featuring convolution terms in the excitation and radiation forces. This implies that past waves radiated by the body continue to impact future dynamics. Irregular long-crested waves, generated from the Bretschneider spectrum, serve as the incident waves for the study. The model’s accuracy in capturing the dynamics and power absorption of the farm is demonstrated through validation against experimental data from a 1:10 scaled prototype of a six-point-absorber array. Despite inherent differences between the experimental and numerical set-ups, the model accurately represents the farm’s behavior. Furthermore, an efficiency test reveals that the numerical scheme approximates the performance of wave power farms comprising 6, 12, 24, 48, and 96 interacting devices within a maximum computational time of 20 s. Overall, this research presents a novel and accurate time-domain model for analyzing an array of point-absorber wave energy converters. The model’s ability to capture the dynamics and power absorption, along with its efficiency in simulating larger wave power farms, make it a valuable tool for the preliminary design stage.

Identification of reaction wheel assembly disturbances based on variable modal frequencies

Micro-vibrations of the reaction wheel assembly (RWA) can have a negative impact on spacecrafts’ attitude control, surveillance, and measurement. Evaluating the micro-vibration magnitude during the design stage is possible by establishing an accurate dynamic model of the RWA disturbance characteristics and identifying the relevant parameters. Doing so can provide references for spacecraft design and development, ultimately leading to more efficient and effective spacecraft operations. However, the conventional methods of modeling and identifying the RWA and of predicting the distribution and magnitude of the disturbing force/torque are limited, as it relies on stable and constant modal frequencies. In the development mission of a satellite, a specific scenario is found that the modal frequency of the RWA changes with speed. This study proposes a novel modeling and parameter identification method for the RWA disturbances based on variable modal frequencies and is advantageous in this scenario. The RWA’s dynamic model is considered a covariant system related to the rotational speed. Additionally, frequency-domain and time-domain models have been established for the RWA’s translational and swinging motions. Simultaneously, the identification method of the model parameters is developed, which involves identifying the harmonic factors, the variable modal frequencies, and the amplitude coefficients. Finally, the method is validated by numerical simulations and experiments. The results indicate that the proposed method offers excellent identification performance, surpassing conventional methods in model accuracy and identification performance. This achievement holds significant reference value in the micro-vibration suppression and optimization design of spacecraft.

Including Blade Elasticity into Frequency-Domain Propeller Whirl Flutter Analysis

Whirl flutter as an aeroelastic instability can be a limiting factor in the design and certification of turboprop aircraft configurations, especially for the engine suspension. Whirl flutter prediction for these configurations is currently done in the frequency domain using rigid propeller aerodynamic derivatives. Blade flexibility is neglected in this process, although it is known to have an impact on whirl flutter predictions. This paper uses frequency-domain transfer matrices for the propeller hub loads identified from a time-domain multibody simulation model of an isolated turboprop propeller and included into a frequency-domain flutter analysis to study the impact of blade elasticity on propeller whirl flutter. Results demonstrate a significantly stabilizing effect of blade elasticity on propeller whirl flutter due to a reduction of the destabilizing pitch-yaw cross-coupling moment. The method demonstrated in this paper is applicable to arbitrary time-domain propeller models and compatible with standard frequency-domain flutter processes, allowing for increased fidelity in the flutter prediction process.

Effect of long-term lateral cyclic loading on the dynamic response and fatigue life of monopile-supported offshore wind turbines

Offshore wind turbines are often supported on monopiles and are always subjected to long-term cyclic loading during their service life. This cyclic loading induces changes in the damping, stiffness and permanent accumulated rotation of the monopile foundation. The main purpose of this paper is to investigate the effect of these three changes occurring simultaneously on the dynamic response and fatigue life of offshore wind turbines in sand. To this end, an integrated methodology is presented based on time-domain finite element model and small-scale model tests of rigid piles. Three states of the monopile foundation are selected and defined based on the operational time of the turbine. The results show that these three changes have a slight effect on the dynamic response of offshore wind turbines, but have a significant effect on the fatigue life. The fatigue life decreased from 23.3 years for the initial state to 20.99 years for the medium state and 19.45 years for the ultimate state, a decrease of 10% and 16.5%, respectively, indicating that these changes should be addressed in the design of the fatigue life calculation of offshore wind turbine structures. The systematic parametric analysis shows that soil damping has the greatest effect on the dynamic response and fatigue life, followed by soil stiffness, which is less affected by permanent accumulated rotation.

Mechanistic research on the complex motion response of a TLP in a tender-assisted drilling state

In this study, nonlinear motion characteristics have been studied in the coupled behavior of a Tension Leg Platform (TLP) combined with a Tender-assisted Drilling Unit (TADU). A time-domain numerical model has been established that accounts for the nonlinear behavior of mooring systems and hydrodynamic interference. Experiments are performed to verify the numerical model. Nonlinear motion characteristics of the steady-state response of the time-domain results are analyzed using Poincaré mapping and fast Fourier transform. The focus of this study is on investigating the motion response of the TLP platform in three degrees of freedom under coupled states. The surge motion is found to mainly consist of the wave frequency component and the half-wave frequency subharmonic component, while the wave-frequency, subharmonic, and super harmonic vibration components are observed in both heave and pitch motions. Three types of nonlinear regimes, namely chaos, transition, and multiple periodic, are identified in the heave and pitch motions under different wave conditions.

A general jitter analysis of DLL considering the jitter accumulation effect of loop capacitor

This paper presents a time-domain model for general jitter analysis of delay-locked loops (DLLs). According to this model, the noise contribution of each part of the circuit is specified at the output of DLL, and a closed-form relationship is extracted. By this closed-form relationship, we show that accumulated jitter, known as jitter peaking, always exists due to the loop filter capacitor in a widely used DLL configuration. The effect of jitter accumulation can cause an unstable lock state. A conventional DLL is simulated in 0.18 µm CMOS technology to verify the closed-form relationship.

Numerical modelling of a catamaran float-over deck installation for a spar platform with complex hydrodynamic interactions and mechanical couplings

Multi-body system is becoming common in engineering practice, such as the catamaran float-over installation for a Spar platform, one of the most complex marine systems. Gap resonance phenomenon occurs in the catamaran float-over system due to strong hydrodynamic interactions, inducing inaccuracy in evaluations of the hydrodynamic coefficients. To obtain reasonable hydrodynamic coefficients, the damping lid method in AQWA, which provide viscous correction for the potential flow theory, is first validated and then applied to the model in this study. It is found that the damping lid is capable of dealing with the gap resonance phenomenon. With the introduction of the damp lid method in the catamaran float-over system with α = 0.20, the relative error between frequency-domain and time-domain declined from 690% to 1.7%. Based on the corrected frequency-domain results, a time-domain model, considering various types of mechanical coupling components in the float-over system, including LMUs, DSUs, steel-to-steel impacts on LMUs, lateral constrains of LMUs and DSUs, sway fenders, hawsers and the mooring system. Simulations for first contact stage and last contact stage under different incident wave angle are performed. It is observed that the relative motions under quartering sea in first contact stage are the largest. Furthermore, in order to reveal the coupling mechanism, different configurations of the barges and Spar are investigated for the first contact stage under irregular waves. It is found that the relative heave motions on the LMUs are larger when the deck and barges are rigidly connected to form a catamaran-barge.

Nonlinear resonant ultrasound spectroscopy using white-noise excitation

Nonlinear resonant ultrasound spectroscopy (NRUS) is a technique for non-destructive sample evaluation by which a strain-dependent nonlinear parameter is quantified that exhibits heightened sensitivity to defects as compared to monitoring of linear resonance attributes. As NRUS measurements have traditionally used a controlled sweep of sinusoidal inputs, applications of the method have been largely limited to laboratory experiments. Here we present NRUS results which utilized a white noise signal as input, in order to better approximate ambient excitation and facilitate efficient validation using time-domain models. Studied samples were chosen to reflect a range of nonlinear responses and underlying mechanisms (acrylic, sandstone, fractured steel). We excited the studied samples using bonded piezoelectric transducers which delivered white-noise inputs at increasing amplitudes, with the nonlinear response measured with a laser doppler vibrometer. By comparing results against those obtained from traditional NRUS, we find comparable trends in the nonlinear parameter under white-noise excitation, including similar relative differences in magnitude across the samples and consistent values across similar mode shapes. While we note that white-noise strain estimation is complicated by simultaneous excitation of multiple resonant modes, NRUS results from white-noise excitation demonstrate promising viability of the technique for (1) in-situ inspection, and (2) a more-tractable approach to model the physics of various NRUS signals.

Analysis of the Precision of CSST Time-domain Photometric Observation

The Chinese Space Station Telescope (CSST) is the first space optical survey telescope of China. It will perform scientific observations and yield important scientific results, e.g. multi-color photometry to find and characterize exoplanets. The precision of time-domain photometry affected by various astrophysical and instrument noises is crucial for exoplanet detection and characterization. This paper constructs a time-domain model to simulate the stellar signal and various noises based on the main technical parameters of CSST published so far. The precision of photometry is analyzed by modeling the signal and noises for an example of the gazing mode in the i-band. We investigate and discuss the contribution of various noise sources in aperture photometry, especially the jitter noise caused by pointing jitter and pixel response inhomogeneity. The test results also provide the recommended aperture sizes for photometry. Jitter noise can be suppressed by reducing jitter amplitude, uniforming pixels, or using differential photometry with reference stars. Our simulation results have broad applications, including precision predictions for time-domain photometry, the refinement of CSST instrumental specifications, the evaluation of exoplanet detection capabilities, and improvements in data reduction progress for CSST.

Time–frequency domain based optimization of hedging strategy: Evidence from CSI 500 spot and futures

Considering the significance of the frequency domain information in price series, we propose a decomposition-integration hedging model from the perspective of time–frequency domain to improve the hedging effectiveness and robustness. First, the returns series of spot and futures are decomposed and reconstructed into high frequency, medium frequency, and low frequency sequences to incorporate the frequency information into the hedging model. Then, we construct a model pool to fit the various characteristics of the data in each frequency domain and further extract the corresponding information. Finally, by taking four moments of investors risk appetite into consideration, the multi-objective optimization is employed to integrate the final hedging ratio. The empirical results indicate that the decomposition-integration hedging model is superior to the single time domain models in comprehensive evaluation indices. In addition, within a certain range of market fluctuations, the structure of our model has some characteristics that are compatible with reality. To recapitulate briefly, the hedging ratio of our model is mainly determined by the high frequency and medium frequency information under drastic market fluctuations. While when the market volatility is small, the hedging ratio largely depends on low frequency information.

Multi-center atrial fibrillation electrocardiogram (ECG) classification using Fourier space convolutional neural networks (FD-CNN) and transfer learning

There has been a proliferation of machine learning (ML) electrocardiogram (ECG) classification algorithms reaching >85% accuracy for various cardiac pathologies. Despite the high accuracy at individual institutions, challenges remain when it comes to multi-center deployment. Transfer learning (TL) is a technique in which a model trained for a specific task is repurposed for another related task, in this case ECG ML model trained at one institution is fine-tuned to be utilized to classify ECGs at another institution. Models trained at one institution, however, might not be generalizable for accurate classification when deployed broadly due to differences in type, time, and sampling rate of traditional ECG acquisition. In this study, we evaluate the performance of time domain (TD) and frequency domain (FD) convolutional neural network (CNN) classification models in an inter-institutional scenario leveraging three different publicly available datasets. The larger PTB-XL ECG dataset was used to initially train TD and FD CNN models for atrial fibrillation (AFIB) classification. The models were then tested on two different data sets, Lobachevsky University Electrocardiography Database (LUDB) and Korea University Medical Center database (KURIAS). The FD model was able to retain most of its performance (>0.81 F1-score), whereas TD was highly affected (<0.53 F1-score) by the dataset variations, even with TL applied. The FD CNN showed superior robustness to cross-institutional variability and has potential for widespread application with no compromise to ECG classification performance.

Stable parameters identification for rational approximation of Single degree of freedom frequency response function of semi‐infinite medium

AbstractThe rational approximation is an important tool for establishing a dynamic analysis model in time domain for semi‐infinite water and soil. It accurately represents the interaction between the semi‐infinite medium and an engineering structure. Current research on rational approximation method focuses mainly on the establishment of time‐domain analysis models. However, the stability, accuracy, and calculation efficiency of the rational approximation model cannot be guaranteed simultaneously. Based on linear system control theory, this work decomposes the continuous‐time rational approximation (CRA) and the discrete‐time rational approximation (DRA) into a combination of first‐ and second‐order subsystems, and the stability boundaries for the identified parameters are established according to the stability conditions of each subsystem. A genetic algorithm and a sequential quadratic programming algorithm are used to construct a parameter identification method that can ensure stability in the time domain. Through parameter identification of complex frequency response functions, it is demonstrated that the method proposed in this work can guarantee the stability and accuracy simultaneously, and the calculation efficiency is also substantially improved over that of the existing methods.

Conceptual design and optimisation of a novel hybrid device for capturing offshore wind and wave energy

AbstractThe access to the offshore wind resource in the deep sea requires the development of innovative solutions which reduce the cost of energy. Novel technologies propose the hybrid combination of wind and wave energy to improve the synergy between these technologies sharing costs, such as mooring and electrical connexion. This work proposes a novel hybrid wind and wave energy system integrating a floating offshore wind turbine with three-point absorbers wave energy converters (WECs). The WECs are an integral part of the floating structure and contribute significantly to the hydrostatic and dynamic stability of the system. Their geometry is optimised considering a cylindrical, semi-cylindrical and spherical shape for the Pantelleria case study. The cylindrical shape with the largest radius and the lowest height is the optimal solution in terms of reducing structural costs and maximising the performance of the WECs. The in-house hydrostatic stability tool and the time domain model MOST are used to optimise the WECs, with a combined meta-heuristic genetic algorithm with the Kriging surrogate model and a local Nelder–Mead optimization in the final simulations. The power of the WECs is estimated with both linear and variable motor flow hydraulic PTOs to obtain a more realistic electrical power generation. Generally, the hybrid device proved to be more competitive than the floating wind turbine alone, with a LCOE reduction up to 11%. Performance of the hybrid device can be further improved when more energetic sites are considered, as the energy generated by the WECs is higher.

Spectral-Domain Modelling of Wave Energy Converters as an Efficient Tool for Adjustment of PTO Model Parameters

The power take-off (PTO) system is a core component in WECs as it plays a critical role in power production. In numerical models the PTO systems are commonly represented and simplified through a combination of linear stiffness and damping terms in the equations of motion. These parameters are influential to the dynamic response and thus affect the power performance of WECs. In the preliminary design and optimization of WECs, proper tuning of the PTO damping and stiffness could reflect better the potential of the concept. In practice, the PTO damping and stiffness are tuned to maximize the absorbed power by achieving the desired velocity amplitude or phase of the velocity with respect to the excitation force. However, recent literature has indicated that the selection of PTO parameters for maximum mechanical power absorption is not necessarily optimal for the maximum production of electrical power when the conversion efficiency of the electrical machine is included. To obtain these parameters which maximize the delivered electrical power, wave-to-wire models are widely used. Nevertheless, wave-to-wire models are predominately established by using time-domain models which can be associated with large computational efforts from the perspective of early-stage design and concept evaluation. To tackle this challenge, a spectral-domain-based wave-to-wire model is proposed to cover both hydrodynamic and electrical responses. In this paper, a spherical heaving point absorber integrated with a linear permanent-magnet generator is used as reference. The relevant nonlinear effects are incorporated by statistical linearization using spectral-domain modelling. In particular, the nonlinear effects considered in this work include the viscous drag force, the electrical current saturation and the partial overlap between the translator and stator components of the linear generator. The model results are then verified against a nonlinear time-domain-based wave-to-wire model. Subsequently, the proposed model is applied to identify the PTO parameters for maximizing the electrical power in various wave states. The computational efficiency and accuracy of the proposed spectral-domain model are compared with the time-domain model, with regard to the identification of the proper PTO damping and stiffness. Based on the results, the advantage of using the spectral-domain-based wave-to-wire modeling in PTO tuning is demonstrated.

Numerical investigations on energy conversion performances in twin standing-wave thermoacoustic engines with various geometric and operational conditions

The present work considers the heat-driven acoustic characteristics and dynamic thermal-fluid flow fields in a twin standing-wave thermoacoustic engine (TSWTAE). Emphasis is placed on enhancing its acoustic power output performances for efficiently driving thermoacoustic refrigerators by varying operating conditions and geometric shapes. For this, a time-domain 2D twin TAE model is developed to analyze the TSWTAE in the presence of different working gases and various operating pressures first. It is then applied to examine the geometry effect on the thermo-acoustics energy conversion performances of the twin SWTAE. The model is validated by comparing with those results obtained from DeltaEC (Design Environment for Low-amplitude ThermoAcoustic Energy Conversion) software and experimental data available in the literature. The results indicate that the acoustic oscillation pressure and sound pressure level are increased with the charge pressure and the molecular weight of the working gases, while the acoustic power and thermo-acoustics energy conversion efficiency of the different working gases remain roughly constant. Considering the comprehensive acoustic characteristics, the optimal engine performance is achieved with a 0.6 MPa charge pressure, as helium is applied. Furthermore, the implementation of the tapered conical resonator demonstrates a substantial enhancement in oscillation pressure and thermal efficiency, yielding improvements of 82.03% and 32.60% respectively compared to the utilization of a cylindrical narrow resonator in the experimental setup. The present study provides a design tool for predicting and optimizing twin SWTAE performances.

Development &amp; performance enhancement of an AUV wave-charging system

Adoption of autonomous underwater vehicle (AUV) technology has recently experienced rapid growth, fueled by possibilities enabled by technological advances. AUVs are particularly useful as unmanned survey platforms, and typically have an array of on-board sensors to collect data for a variety of commercial and military applications. AUVs are autonomous and untethered systems and require a power source, typically batteries, to be carried onboard. An increase in available energy by even a small amount can be game-changing for AUV applications with benefits including longer mission durations, higher sampling rate, more sensing capability, and improved communication capability. This can be accomplished through some self-recharging capability within the AUV, allowing the AUV to extract energy from its surrounding environment, and eliminating the need to recover the vehicle until the mission is complete. &#x0D; This work presents a Wave Power Capture System (WPCS) that can be integrated into an AUV, allowing it to operate for significantly longer periods of time without the need for recovery. This concept utilizes two rotary power take-off (PTO) units that are driven by two independent tendons, located axially along the length of the body. The two tendons are connected to a retractable reaction plate that can be stowed against the body of the AUV when not in use and deployed autonomously when the AUV needs to surface and recharge. This arrangement allows both pitch and heave motion to be primary contributors to relative (power generating) motion. Additional motion in surge, sway and yaw will also result in some secondary power generation.&#x0D; This work focuses on the hydrodynamics and design of the reaction plate so that power capture and quality are enhanced. The geometry of the reaction plate will be constrained to a baseline semicircular shape, allowing the AUV to operate normally when the plate is stowed. Based on previous work, which has indicated that increasing the reaction plate added mass improves WEC power capture, the current work will thus look at different modifications to the reaction plate that effectively enhance its size when deployed, for example, incorporating multiple ‘nested’ reaction plates that mate together when stowed. The light weight of the reaction plate relative to its size means that there may be a tendency for the tendons to go slack and subsequently experience snap loading in cases where the reaction plate does not fall as fast as the AUV body. This work will further investigate the incorporation of dynamically adaptable geometries that reduce the reaction plate’s hydrodynamic resistance in the downward direction, for example, a structure that contains multiple flaps that hinge open during downward travel.&#x0D; A series of experiments will be presented in which the different reaction plate concepts are sinusoidally forced in a quiescent basin to characterize the translational and rotational hydrodynamic coefficients over a range of representative frequencies and amplitudes. Finally, a time-domain model developed using ProteusDS software, informed by the hydrodynamic coefficients measured experimentally, will be used to calculate AUV power performance in different sea states and evaluate the effect of the different reaction plate modifications.

Numerical investigation of a new hybrid floating wind turbine concept

In today’s energy scenario dominated by the need to develop new methods of generating electricity, energy-intensive infrastructures are a promising solution towards energy self-sufficiency and environmental sustainability. Floating offshore wind turbine represents one of the major solution to exploit renewable energies. Currently, the increase of offshore wind market opens up the possibility of integrating different technologies to take advantage of marine energy potential, in particular wave energy.&#x0D; This work presents a new wave-wind hybrid floating platform with three Oscillating Water Columns (OWC) integrated in a floating offshore wind spar buoy. The design methodology is described showing the size of geometric characteristics of OWCs and the size of the energy conversion system. The hybrid system is investigated by a time-domain model that integrates the wind turbine model, the hydrodynamics of the floater, the thermodynamics of the OWC air chambers, and the damping effect induced by the OWC air turbine. The thermo-aero-hydro coupled numerical framework is described to highlight the implementation of the thermodynamic model in WEC-Sim/MATLAB environment. Specifically, the water column dynamics are solved as pistonrigid body representation, enabling the time-domain analysis of the OWC dynamic behaviour. Impulse turbines are considered as OWC Power Take-Offs (PTO). The resource scenario of Mediterranean Sea is considered as case study, in terms of both wind and wave conditions. The analysis focuses on the power extraction capabilities of the OWCs and on the impact of OWCs on the productivity of the wind turbine. Further developments on multi-objective design tools and on optimal PTO control design aiming power maximisation could be conducted for hybrid energy platforms based on this established numerical framework.

Upsampling wave temporal resolution: Investigating wave parameters and the influence on WEC power performance

Power production of wave energy converters (WEC) predicted in the time domain utilize wave resource parameters and time-domain hydrodynamic model simulations of the WEC. While the hydrodynamic model provides high temporal resolution of power production (10’s of Hz), the wave resource parameters are often based on frequency-domain calculations with temporal resolution of 30 minutes to an hour. However, real ocean wave conditions vary on much shorter time scales. Relying on frequency-domain calculations will not be sufficient to capture the short-term variability and accurately predict WEC power production for a standardized methodology that follows power system requirements. These requirements need forecasted data with high sampling frequency for accurate energy predictions. Looking specifically at resource characterization, high temporal resolution datasets are not publicly available or do not exist for many coastal locations. Due to data availability, low temporal resolution datasets are being used in a majority of studies to generate representative wave conditions as inputs to numerical simulations. Representative wave conditions are used to generate wave spectrums. The issue with this practice is spectrums are then used to predict the efficiency of systems that will not accurately capture the variability of waves in short timeframes. Creating a standardized methodology to increase the temporal resolution of metaocean conditions to inform model development can provide better forecasting of power production. Random amplitude, Fourier coefficient methods have been suggested for WEC simulations of finite durations to improve the observed variability in wave heights and power production. Variability using this method does increase for finite durations compared to the commonly used deterministic amplitude method. In this paper we will investigate the influence of wave parameters (significant wave height, maximum wave height, and energy period) on the prediction of WEC power production. A better understanding of the influence of these parameters will provide a path towards future standardization methodology for resource inputs for time-domain modeling.