Performance of an Ocean Energy Conversion System with DFIG Sensorless Control

Abstract

The 2009/28/EC Directive requires Member States of the European Union to adopt a National Action Plan for Renewable Energy. In this context, the Basque Energy Board, EVE, is committed to research activities such as the Mutriku Oscillating Water Column plant, OWC. This is an experimental facility whose concept consists of a turbine located in a pneumatic energy collection chamber and a doubly fed induction generator that converts energy extracted by the turbine into a form that can be returned to the network. The turbo-generator control requires a precise knowledge of system parameters and of the rotor angular velocity in particular. Thus, to remove the rotor speed sensor implies a simplification of the hardware that is always convenient in rough working conditions. In this particular case, a Luenberger based observer is considered and the effectiveness of the proposed control is shown by numerical simulations. Comparing these results with those obtained using a traditional speed sensor, it is shown that the proposed solution provides better performance since it increases power extraction in the sense that it allows a more reliable and robust performance of the plant, which is even more relevant in a hostile environment as the ocean.

State-space Coil Modelling in Plasma Magnetic Confinement Devices

“…In turn, current is controlled indirectly through voltage, as these signals are dependent each other. There exist different control approaches for this purpose, being the most used traditional PID-based schemes, robust (sliding-mode) schemes and MPC schemes [11][12][13][14][15][16][17][18][19][20][21][22][23]. In particular, when dealing with fusion devices where the available energy is limited, MPC is especially interesting due to its ability to ensure that both the control action and the solution error are minimal [9].…”

“…The MPC scheme used is shown in Figure 5. The model used for the design of the MPC implementation is based on the previously obtained state-space (15)(16) [27,28]. In order to develop an optimal controller, and given that the state variables are not coupled, the state-space model may be expressed as follows:…”

Modeling and SIL simulation of an oscillating water column for ocean energy conversion

“…This is commonly known as the stalling behaviour of the Wells turbine. The peak value may change depending on the characteristics of each turbine [20]. , the torque and, therefore, the turbine efficiency drop drastically during the stalling behaviour depending on the rotational speed.…”

“…As a result, the performance of the Wells turbine is limited by the stalling phenomenon on the turbine blades. This is the reason why control is particularly relevant in Wells turbines [6], [7], [20].…”

Power Consumption Analysis of Microprocessor Unit Based on Software Realization

“…Hardware techniques in most cases use power optimization at the level of registers, gates or transistors [2], [10], [11]. Such optimization can be supported for example by performing numerical simulations [12], [13]. This paper refers to software level power consumption analysis of MCU (microcontroller), focusing mainly on instruction and data realization, hence techniques of hardware optimization are not taken under further consideration.…”