Paula B. Garcia Rosa

Paula B. Garcia Rosa
SINTEF | Stiftelsen for industriell og teknisk forskning · Energy Systems

Electronic Engineering, MSc in Electrical Engineering, DSc in Ocean Engineering

About

38
Publications
6,093
Reads
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269
Citations
Additional affiliations
February 2020 - present
SINTEF
Position
  • Researcher
February 2018 - January 2020
Norwegian University of Science and Technology
Position
  • PostDoc Position
April 2016 - March 2017
Norwegian University of Technology and Science
Position
  • Fellow

Publications

Publications (38)
Conference Paper
Full-text available
Wave energy converters (WECs) are still at an earlier stage of development when compared to variable renewable energy systems based on wind or solar power. Indeed, only a few WECs have exported power to electric grids until recently. Thus, the development of mathematical models able to represent essential aspects of the system and its connection to...
Article
Full-text available
Concepts for control of wind farms can be clustered into two distinct concepts, namely wind power plant control and wind farm flow control. Wind power plant control is concerned with the connection to the power system, compliance with grid codes and provision of power system services. This comprises the traditional way of operating a wind farm with...
Article
Full-text available
Wave energy emulators provide an option to extend studies of wave energy converters (WECs) in an electric power laboratory facility and to evaluate the performance of controllers in an experimental set-up. In addition, the integration of control strategies in different steps of the energy conversion process is an important step to improve the WEC o...
Article
Full-text available
Wind farm control (WFC) allows coordinated operation of the wind turbines within a wind power plant (WPP). However, its development has traditionally been split into the distinct disciplines of power plant control and farm flow control. As variable renewable energies, in particular wind energy, increase their penetration into the power system, grid...
Conference Paper
This paper presents an approach for assessing the most suitable locations to provide virtual inertia by HVDC converters. A frequency deviation index quantifying the maximum distance in Hz from each bus in the power system to the Center of Inertia (COI) is utilized as the starting point of the assessment. From this index, the buses that are exhibiti...
Article
In this paper, the automatic control of a single unmanned surface vehicle (USV) pushing a floating load is developed and theoretically analyzed. This represents a challenging control problem, since the manipulated load is underactuated and its open-loop dynamics is inherently unstable. Thus, a stabilizing controller must be designed. To this end, a...
Presentation
Full-text available
This is the presentation of the paper: "Effect of non-ideal power take-off on the electric output power of a wave energy converter under suboptimal control", presented at the RENEW 2020 - 4th International Conference on Renewable Energies Offshore, 12-15 October 2020, Lisbon, Portugal.
Conference Paper
Full-text available
This work investigates how the physical limitations and losses of an electric power takeoff (PTO) system affect the production of power for a wave energy converter (WEC) under suboptimal control strategies. The damping of the PTO system is either continuously tuned to the time-varying wave excitation force frequency, which is referred to as passive...
Conference Paper
Full-text available
Aiming at improving the energy absorption from waves, a number of studies have considered declutching control-a phase-control method that consists of disengaging the power takeoff (PTO) system from the oscillating body at specific intervals of time. The on/off sequences with the instants to engage/disengage the PTO are usually determined by optimiz...
Data
Movie of an experimental result of "Stabilizing Control of an Unmanned Surface Vehicle Pushing a Floating Load".
Article
Aiming at improving the energy absorption from waves, a number of studies have considered declutching control – a phase-control method that consists of disengaging the power take-off (PTO) system from the oscillating body at specific intervals of time. The on/off sequences with the instants to engage/disengage the PTO are usually determined by opti...
Conference Paper
Full-text available
A great improvement in the absorption of energy of a wave energy converter (WEC) is obtained with a time-varying power takeoff (PTO) damping over a constant damping. In a passive control scheme based on the Hilbert-Huang transform (HHT), the PTO damping is time-varying and tuned to the instantaneous frequency of the wave excitation force. The HHT m...
Conference Paper
Full-text available
For dynamic positioning operations, high-frequency wave induced motions cause excessive control action, and consequently additional power consumption and wear of actuators in the propulsion system. Thus, such operations require the control of only low-frequency motions, which is achieved by proper filtering of high-frequency motions. This study inv...
Article
Full-text available
A number of wave energy controllers tune the power take-off (PTO) system to the frequency of incident waves. Since real ocean waves are non-stationary by nature and not defined by a single frequency component, the PTO can be either tuned at a constant frequency characterized by the local spectrum, or continuously tuned to a representative wave freq...
Preprint
Full-text available
A number of wave energy controllers tune the power take-off (PTO) system to the frequency of incident waves. Since real ocean waves are non-stationary by nature and not defined by a single frequency component, the PTO can be either tuned at a constant frequency characterized by the local spectrum, or continuously tuned to a representative wave freq...
Conference Paper
Full-text available
Passive loading is a suboptimal method of control for wave energy converters (WECs) that usually consists of tuning the power take-o� (PTO) damping of the WEC to either the energy or the peak frequency of the local wave spectrum. Such approach results in a good solution for waves characterized by one-peak narrowband spectra. Nonetheless, real ocean...
Article
Full-text available
Passive loading is a suboptimal method of control for wave energy converters (WECs) that usually consists of tuning the power take-off (PTO) damping of the WEC to either the energy or the peak frequency of the local wave spectrum. Such approach results in a good solution for waves characterized by one-peak narrowband spectra. Nonetheless, real ocea...
Article
Full-text available
The energy cost for producing electricity via wave energy converters (WECs) is still not competitive with other renewable energy sources, especially wind energy. It is well known that energy maximising control plays an important role to improve the performance of WECs, allowing the energy conversion to be performed as economically as possible. The...
Conference Paper
Full-text available
This work describes the overall aspects of the Competition on Hydrodynamic Modelling of a Rigid Body, a competition outlined to evaluate different ways to model and simulate the motions of a rigid body in waves. The main objective is to determine a hydrodynamic model for a submerged horizontal cylinder which best predicts a recorded motion to a spe...
Article
Full-text available
Somewhat similar to wind farms, commercial wave energy will be realized using farms of devices. However, for wave farms, both constructive and destructive interference may occur between individual devices; whereas, for wind farms, only destructive interference occurs. In order to maximize constructive interference, the layout of the wave farm must...
Article
Full-text available
Wave energy converters (WECs) are traditionally designed independently of control systems. This usually involves matching the device frequency response to the predominant sea spectrum of a specific site. Energy maximizing control systems are subsequently employed to improve the energy conversion of the device for sea states other than the design se...
Article
This paper addresses the dynamic modeling and the energy storage analysis of a wave energy hyperbaric converter, which consists of a set of oscillating bodies (named as pumping modules) linked to hydropneumatic accumulators and an electric generating unit. A mathematical model of the accumulator is presented and a model for the generating unit is p...
Conference Paper
A device for electricity generation from ocean waves has been developed for installation on the Brazilian northeast coast. It is based on pumping modules and a two-stage accumulator linked to a hyperbaric chamber in order to provide a prescribed high pressure water flow, which operates a turbine coupled with an electrical generator. In the period b...
Conference Paper
In this work, we consider the optimization problem of ocean wave energy absorption in oscillating-body systems. A solution based on discrete-time extremum seeking control is proposed to improve the mean extracted power by a power take-off (PTO) mechanism under different wave climates. Two different PTO mechanisms are considered: a linear and a non-...
Conference Paper
This paper presents a comparative analysis between the double-feed induction generator (DFIG) and directly connected squirrel cage induction generator (SCIG) when they are used in a wave energy conversion system. Simulation results are presented to illustrate the operating ranges of the asynchronous generators and the generated power by the system....
Article
Oscillating bodies represent an important class of wave energy converters (WECs). In these systems, the steps of converting wave energy into electricity usually employ a floating body that is either connected to a hydraulic system and a turbine (or motor) coupled to an electric generator or connected directly to a linear electric generator. The imp...
Conference Paper
Full-text available
This work describes the mathematical modeling of a system based on ocean wave conversion into electricity. An analysis of the hydrodynamic, mechanical and electrical characteristics of the subsystems that compose the converter is done and the mathematical models are presented. Simulation results are presented to assess the levels of the generated p...
Conference Paper
Full-text available
In this work, a hydraulic turbine speed governor is proposed in view of its application in an isolated electric generation system based on an ocean wave energy converter (WEC). The proposed strategy is based on cascade closed-loop control combined with feedforward of load disturbances. The main characteristics of a WEC are presented and a dynamic m...
Conference Paper
Full-text available
This paper considers the problem of optimizing the efficiency of the primary conversion on an ocean wave energy hyperbaric converter. This wave energy converter (WEC) is an oscillating-body linked to a hyperbaric chamber. By solving the equation of motion of the power take-off mechanism, it is shown that optimal conditions for improving the absorbe...
Conference Paper
Full-text available
In this work, a hydraulic turbine speed governor is proposed in view of its application in an isolated system based on wave energy electricity generation. The proposed strategy is based on cascade controllers combined with feedforward. The main characteristics of a wave energy converter prototype are presented and a generating unit model is conside...

Projects

Projects (2)
Project
There are three main types of ocean technology: wave, tidal and ocean thermal. The European Commission has issued a strategy to harness the potential of offshore renewable energy as one target in phasing out fossil fuels and to stimulate a cleaner industrial activity - scaling up the Carbon Neutrality Goal by 2050, and the sustainable development goal by 2030. The offshore energy systems industry remains to be an important research value chain investing in those developments. This group keeps track of the progress made and offers a systematic review of offshore renewable systems. Notes and contributions are useful for preprints, proceedings submissions, working journal papers, and materials for teaching.
Project
Non-stationary signal analysis in Modern Electric Power Systems (Smart Grid, Microgrids) by introducing the concept of Instantaneous Frequency (IF) as a descriptor or the measured physical phenomena.