Energy Storage Technologies for Smoothing Power Fluctuations in Marine Current Turbines

With regard to marine renewable energies, significant electrical power can be extracted from marine tidal current. However, the power harnessed by a marine current turbine varies due to the periodicity of the tidal phenomenon and could be highly fluctuant caused by swell effect. To improve the power quality and make the marine current generation system more reliable, energy storage systems will play a crucial role. In this paper, the power fluctuation phenomenon is described and the state of art of energy storage technologies is presented. Characteristics of various energy storage technologies are analyzed and compared for marine application. The omparison shows that high-energy batteries like sodiumsulphur battery and flow battery are favorable for smoothing the long-period power fluctuation due to the tide phenomenon while supercapacitors and flywheels are suitable for eliminating short-period power disturbances due to swell or turbulence phenomena. It means that hybrid storage technologies are needed for achieving optimal performance in marine current energy systems

Hybrid Generation Systems Planning Expansion Forecast: A Critical State of the Art Review

International audienceIn recent years the electric power generation has entered into a new development era, which can be described mainly by increasing concerns about climate change, through the energy transition from hydrocarbon to clean energy resources. In order to power system enhance reliability, efficiency and safety, renewable and nonrenewable resources are integrated together to configure so-called hybrid systems. Despite the experience accumulated in the power networks, designing hybrid system is a complex task. It has become more challenging as far as most renewable energy resources are random and weather/climatic conditions-dependant. In this challenging context, this paper proposes a critical state-of-the-art review of hybrid generation systems planning expansion and indexes multi-objective methods as strategies for hybrid energy systems optimal design to satisfy technical and economical constraints

LineMarkNet: Line Landmark Detection for Valet Parking

We aim for accurate and efficient line landmark detection for valet parking, which is a long-standing yet unsolved problem in autonomous driving. To this end, we present a deep line landmark detection system where we carefully design the modules to be lightweight. Specifically, we first empirically design four general line landmarks including three physical lines and one novel mental line. The four line landmarks are effective for valet parking. We then develop a deep network (LineMarkNet) to detect line landmarks from surround-view cameras where we, via the pre-calibrated homography, fuse context from four separate cameras into the unified bird-eye-view (BEV) space, specifically we fuse the surroundview features and BEV features, then employ the multi-task decoder to detect multiple line landmarks where we apply the center-based strategy for object detection task, and design our graph transformer to enhance the vision transformer with hierarchical level graph reasoning for semantic segmentation task. At last, we further parameterize the detected line landmarks (e.g., intercept-slope form) whereby a novel filtering backend incorporates temporal and multi-view consistency to achieve smooth and stable detection. Moreover, we annotate a large-scale dataset to validate our method. Experimental results show that our framework achieves the enhanced performance compared with several line detection methods and validate the multi-task network's efficiency about the real-time line landmark detection on the Qualcomm 820A platform while meantime keeps superior accuracy, with our deep line landmark detection system.Comment: 29 pages, 12 figure

Optimal Design of a Stand-Alone Hybrid PV/Fuel Cell Power System for the City of Brest in France

This paper deals with the optimal design of a stand-alone hybrid photovoltaic and fuel cell power system without battery storage to supply the electric load demand of the city of Brest, Western Brittany in France. The proposed optimal design study is focused on economical performances and is mainly based on the loss of the power supply probability concept. The hybrid power system optimal design is based on a simulation model developed using HOMER. In this context, a practical load demand profile of Brest city is used with real weather data

Preliminary Design of A Torus Type Axial Flux Generator for Direct-Driven Tidal Current Turbine

This paper focuses on the preliminary design of a TORUS type AFPM generators used in the MW graded tidal current application. Two different structures can be derived based on the orientation of the main flux. In this paper, an analytical design model for this kind of machine is developed. This model is associated to a basic cost model to estimate the rough cost of the active materials of the machine. This two models are used in a common set of specification corresponding to high power tidal current turbine generator. This method allows a first comparison of these two structures for this application.This work was supported by Shanghai international science and technology cooperation projects (1160707800) and Ph.D. programs foundation of Ministry of Education (20113121110002). The authors are grateful for the support

PPD: A New Valet Parking Pedestrian Fisheye Dataset for Autonomous Driving

Pedestrian detection under valet parking scenarios is fundamental for autonomous driving. However, the presence of pedestrians can be manifested in a variety of ways and postures under imperfect ambient conditions, which can adversely affect detection performance. Furthermore, models trained on publicdatasets that include pedestrians generally provide suboptimal outcomes for these valet parking scenarios. In this paper, wepresent the Parking Pedestrian Dataset (PPD), a large-scale fisheye dataset to support research dealing with real-world pedestrians, especially with occlusions and diverse postures. PPD consists of several distinctive types of pedestrians captured with fisheye cameras. Additionally, we present a pedestrian detection baseline on PPD dataset, and introduce two data augmentation techniques to improve the baseline by enhancing the diversity ofthe original dataset. Extensive experiments validate the effectiveness of our novel data augmentation approaches over baselinesand the dataset's exceptional generalizability.Comment: 9 pages, 6 figure

Application of Flow Battery in Marine Current Turbine System for Daily Power Management

Predictable tidal current resources make marine current turbine (MCT) generation system highly attractive as an electricity supply source for coastal areas and remote islands. However, the tidal speed varies greatly due to the flood and ebb tides during one day period. This results large mismatch between MCT produced power and grid-side (or load-side) demanded power. This paper focuses on a grid-connected MCT system and proposes using vanadium redox flow battery (VRB) energy storage system to manage the combined output power and to follow grid-side demand on a daily basis. The VRB model and parameter calculation process are detailed in this paper. The diesel generator (DG) system is considered as a backup power supply source in case of low battery state of charge (SoC) caused by losses during long-time battery operation. Simulations are carried-out on a grid-connected MCT system with VRB ESS to follow a given power demand profile during one day period. The results valid the proposed VRB sizing and control strategy. The DG system is demonstrated as a feasible solution to avoid VRB reaching its low SoC limitation and to guarantee the expected power injection to the local gri

Fuzzy logic based energy management strategy for a fuel cell/battery/ultra-capacitor hybrid ship

In this paper, energy management strategy based on fuzzy logic is proposed for a fuel cell hybrid ship, combining proton exchange membrane fuel cell (PEMFC), battery and ultra-capacitor (UC). This hybrid system aims to optimize power distribution among each energy unit. The simulation model of the fuel cell hybrid power system is established in the MATLAB/SIMULINK simulation environment. The fuzzy logic energy strategy is verified by simulation according to the typical drive cycle of ship. The simulation results show that the proposed energy management strategy is able to satisfy power required by the ship, reduce the dynamic load of fuel cell, maintain the state of charge (SOC) of battery and SOC of the UC, and optimize the performance, fuel economy and efficiency of the hybrid systemThe research is supported by the program of the National Natural Science Foundation (No.61304186 and No.51007056)