scholarly journals Modeling tidal current speed using a Wakeby distribution

2015 ◽  
Vol 127 ◽  
pp. 240-248 ◽  
Author(s):  
Mingjun Liu ◽  
Wenyuan Li ◽  
Roy Billinton ◽  
Caisheng Wang ◽  
Juan Yu
Keyword(s):  
Tidal Current ◽  
Current Speed ◽  
Wakeby Distribution

Investigations Into Tidal Current Turbine System Faults and Fault Tolerant Control Strategies

2020 ◽  
Author(s):  
Xuhua Yan ◽  
Rosemary Norman ◽  
Mohammed A. Elgendy
Keyword(s):  
Tidal Current ◽  
Fault Tolerant ◽  
Control Strategies ◽  
Synchronous Generator ◽  
Fault Tolerant Control ◽  
Current Speed ◽  
Tidal Current Energy ◽  
Speed Sensor ◽  
Tidal Current Turbine ◽  
Current Turbine

Abstract In recent years, there has been a growing interest in tidal current energy as it is a potential source for green electricity generation and the most predictable form of ocean renewable energy. Due to the harsh marine environment, the Tidal Current Turbine (TCT) system has to be designed to be robust and to work reliably with high availability to minimize the need for intervention. Thus, fault tolerant control strategies are needed to enable the system to continue operating under some fault conditions, this will reduce the power generation cost and also increase the system robustness. This paper introduces some of the different fault conditions that may occur in TCT systems such as sensor faults, especially tidal current sensors. Potential solutions for these faults are then introduced. The paper then presents a standalone TCT generation system model with perturb and observe (P&O) control; this control aims to solve the tidal current speed sensor fault problem, ensuring that the system operates near the maximum power point (MPP) without the tidal current speed sensor. The control system is simulated using MATLAB/Simulink, for a TCT, utilizing a permanent synchronous generator (PMSG) and a boost converter.

Rule-of-Thumb Formulas for Extending the Versatility of Tidal Current Tables

2000 ◽  
Vol 34 (2) ◽  
pp. 18-21
Author(s):  
Ben J. Korgen
Keyword(s):  
Tidal Current ◽  
Critical Value ◽  
Tidal Currents ◽  
Current Speed ◽  
Time Interval ◽  
Local Conditions ◽  
Near Surface ◽  
Rule Of Thumb ◽  
Safety Margins ◽  
Scientific Results

Four rule-of-thumb formulas have been derived for use in conjunction with existing tidal current tables. For near-surface tidal currents, these formulas yield 1) the percent of time current speed is above a critical value, 2) the percent of time current speed is below a critical value, 3) the time interval when current speed is above a critical value, and 4) the time interval when current speed is below a critical value. The formulas presented require as inputs the near-surface tidal current speed predictions found in standard tidal current tables. Intended for making rough approximations, these formulas may be useful in planning operations for which information on near-surface tidal currents is important. They are not scientific results or predictive models on which anyone’s life should depend. They should be used only with generous safety margins and if possible, with in situ current measurements, since local conditions may vary considerably.

scholarly journals MPPT of Permanent Magnet Synchronous Generator in Tidal Energy Systems Using Support Vector Regression

2021 ◽  
Vol 13 (4) ◽  
pp. 2223
Author(s):  
Ahmed G. Abo-Khalil ◽  
Ali S. Alghamdi
Keyword(s):  
Permanent Magnet ◽  
Support Vector Regression ◽  
Tidal Current ◽  
High Efficiency ◽  
Synchronous Generator ◽  
Current Speed ◽  
Maximum Power ◽  
Support Vector ◽  
Generation System ◽  
Permanent Magnet Synchronous Generator

In this paper, an improved Maximum Power Point Tracking (MPPT) algorithm for a tidal power generation system using a Support Vector Regression (SVR) is proposed. To perform this MPPT, a tidal current speed sensor is needed to track the maximum power. The use of these sensors has a lack of reliability, requires maintenance, and has a disadvantage in terms of price. Therefore, there is a need for a sensorless MPPT control algorithm that does not require information on tidal current speed and rotation speed that improves these shortcomings. Sensorless MPPT control methods, such as SVR, enables the maximum power to be output by comparing the relationship between the output power and the rotational speed of the generator. The performance of the SVR is influenced by the selection of its parameters which is optimized during the offline training stage. SVR has a strength and better response than the neural network since it ensures the global minimum and avoids being stuck at local minima. This paper proposes a high-efficiency grid-connected tidal current generation system with a permanent magnet synchronous generator back-to-back converter. The proposed algorithm is verified experimentally and the results confirm the excellent control characteristics of the proposed algorithm.

Electrical Power Generation by Tidal Flow Acceleration

2007 ◽  
Author(s):  
Dominique Roddier ◽  
Christian Cermelli ◽  
Alexia Aubault
Keyword(s):  
Power Generation ◽  
Tidal Current ◽  
Electrical Power ◽  
Tidal Flow ◽  
Flow Speed ◽  
Tidal Currents ◽  
Current Speed ◽  
Flow Acceleration ◽  
Renewable Power ◽  
Accelerating Structure

Hydropower is a significant contributor to the renewable power generation sector, but the energy in tidal currents is not commonly used to generate electricity. This is due to the relatively slow speed of tidal currents which does not allow for the economic development of underwater turbines in tidal regions. This paper investigates whether it is possible to increase locally the current speed in regions where the tidal current is normally not strong enough to generate significant power. The device proposed to increase current speed is composed of an arrangement of vertical walls made of poles supporting a thin membrane with suitable profile, referred to as Tidal Current Accelerating Structure or TCAS. Current turbines are to be placed in areas of accelerated flow to convert the current energy into electricity. In this paper, results of model tests that were performed to quantify the ability to increase current speed are discussed. It was found that the increase in flow velocity was not as significant as expected, probably due to interactions between the turbines and the current accelerating devices. Recall potential theory’s flow speed around a disk yields a velocity factor increase of 2 at 90 degrees from the stagnation point.

scholarly journals Optimal Dispatching of Offshore Microgrid Considering Probability Prediction of Tidal Current Speed

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3384
Author(s):  
Zhang ◽  
Sun ◽  
Yang ◽  
Huang ◽  
Feng
Keyword(s):  
Prediction Model ◽  
Quantile Regression ◽  
Regression Model ◽  
Tidal Current ◽  
Operational Reliability ◽  
Current Speed ◽  
Support Vector ◽  
Probabilistic Prediction ◽  
Support Vector Regression Model ◽  
Tidal Current Energy

Oceans contain rich tidal current energy, which can provide sufficient power for offshore microgrids. However, the uncertainty of tidal flow may endanger the operational reliability of an offshore microgrid. In this paper, a probabilistic prediction model of tidal current is established based on support vector quantile regression to reduce the influence of uncertainty. Firstly, the penalty factors and kernel parameters of the proposed prediction model was optimized by the dragonfly algorithm to predict the tidal speed of any time of a day in different quantiles. Secondly, combining the above result with the kernel density to predict the probability density function of the tidal current speed, which is to improve the accuracy of prediction in the absence of information. Thirdly, an optimal generation dispatching strategy with tidal current generators is proposed to minimize the fuel consumption of offshore microgrids. Finally, a case study based on the offshore oil and gas platform in Bohai shows that the mean absolute percent error of the proposed model is 2.8142%, which is better than support vector quantile regression model and support vector regression model optimized by the genetic algorithm.

scholarly journals KARAKTERISTIK MORFOLOGI DASAR LAUT DAN HUBUNGANNYA DENGAN KECEPATAN ARUS LAUT DI SELAT LAMPA, NATUNA, KEPULAUAN RIAU

2017 ◽  
Vol 15 (1) ◽  
Author(s):  
Purnomo Raharjo ◽  
Mario Dwi Saputra
Keyword(s):  
Potential Energy ◽  
Tidal Current ◽  
Alternative Energy ◽  
Current Speed ◽  
Ocean Currents ◽  
Ocean Current ◽  
Small Islands ◽  
Tidal Current Energy ◽  
Study Sites ◽  
Current Energy

Kondisi morfologi dasar laut dari suatu perairan khususnya di selat dapat mempengaruhi kecepatan arus laut. Indonesia sebagai negara kepulauan memiliki banyak pulau dan selat. Bertambahnya kecepatan arus laut dapat dimanfaatkan sebagai salah satu sumber energi yang ramah lingkungan. Selat Lampa yang berada di Pulau Natuna merupakan salah satu wilayah dari pulau-pulau kecil di Provinsi Kepulauan Riau yang masih mengalami krisis energi listrik. Hasil pengukuran kedalaman laut di lokasi penelitian secara keseluruhan berkisar antara 0 meter dan 59,59 meter. Dari hasil penelitian diketahui bentuk morfologi bawah laut pada lokasi ini pada umumnya relatif landai dengan kemiringan sekitar 5o– 10o. Namun pada bagian selat antara Pulau Setanau dan Pulau Setahi memiliki morfologi yang agak curam yang ditunjukkan oleh kontur yang lebih rapat dengan kedalaman berkisar 5 meter sampai dengan 30 meter. Hasil pengukuran dan pemodelan kecepatan arus laut menunjukkan bahwa pada lokasi selat antara Pulau Setanau dan Pulau Setahi memiliki kecepatan arus laut berkisar antara 0,3 meter/detik sampai dengan 1,28 meter/detik. Sehingga lokasi ini sesuai untuk penempatan turbin pembangkit listrik tenaga arus laut.Kata Kunci : Morfologi dasar laut, Kecepatan arus laut, Energi arus laut, Pulau-pulau kecil terluar, Selat Lampa, Pulau Natuna, Kepulauan Riau, Potensi energi listrik tenaga arus lautThe morphology condition of the seabed, especially in the strait, can affect the velocity of ocean currents in these waters. Indonesia as an archipelagic country has many islands and straits. Increasing the speed of ocean currents will be very potential to be utilized as one source of alternative energy that is environmentally friendly. Lampa Strait located on the island of Natuna is one of the small islands in Riau Islands Province which is still experiencing energy crisis. This location was chosen as the location of research for the potential energy of Tidal current. The results of sea depth measurements at the study sites overall ranged between 0 meters and 59.59 meters. From the results of the research is known the underwater morphology at this location is generally relatively sloping with a slope of about 5o to 10o But in the strait between the island of Setanau and Setahi Island has a rather steep morphology shown by a more dense contour with a depth ranging from 5 meters to with 30 meters. The result of ocean current measurement and modeling shows that at the location of the strait between Setanau Island and Setahi Island has a stronger ocean current speed ranging from 0,3 meters / second to 1,28 meters / second. So this location is suitable for the placement of turbines of Tidal current power plants.Keywords : Sub Bottom Profile, Ocean Current speed, Tidal Current Energy, Small outer islands, Lampa Strait, Natuna Island ,Riau Island, potential energy of Tidal current.

Efficiency and Performance Analysis of Tidal Current Energy Turbine Basing on the Unidirectional Fluid-Structure Interaction

2014 ◽  
Vol 672-674 ◽  
pp. 386-391
Author(s):  
Xue Feng Liu ◽  
Jin Bao Wang ◽  
Mei Ling Tian ◽  
Zhi Bo Tang
Keyword(s):  
Performance Analysis ◽  
Tidal Current ◽  
Current Speed ◽  
Structural Performance ◽  
Analysis Method ◽  
Tidal Current Energy ◽  
Structure Interaction ◽  
And Performance ◽  
Safety And Stability ◽  
Current Energy

As the Key Components of a Horizontal Axis Tidal Current Energy(HATCE) Turbine, the Blades will be Affected by the Force of the Fluid when the Turbine is Working, which also Results in a Possible Effect on the Safety and Stability of the Tidal Current Energy Turbine. Thus, both the Structural Performance and Energy-Catching Efficiency of HATCE Turbine should be Paid Equal Attention. in this Study, Basing on the Workbench, the Energy-Catching Efficiency and Structure Performance of the Designed HATCE Turbine with Stainless Steel and Structural Steel at the Different Current Speeds are Comparatively Studied Using Unidirectional FSI Analysis Method. it can be Concluded that the Output Power of the Turbine is Lower at a Low Current Speed but its Energy-Catching Efficiency is Higher and Vise Versa. as a Result of Structure Performance Analysis, the Designed Turbine has Adequate Safetyunder all Loaded Conditions. Thus, the Designed Turbine Models are Available.

Sign in / Sign up

Export Citation Format

Share Document