Performance of Coded Wireless Power Controllers for Wind Turbines Connected to a Smart Grid

Nowadays, with the advance of smart grid technologies, the participation of renewable energy in the power systems is changing for attend new requirements and increase efficiency of the systems. With a view of smart grid context, this work proposes the review of a modern wireless control system proposed based on for squirrel cage induction generators connected to the power grid. The wireless communication system applied transmits the reference power signals to the SCIG controller with the necessary reliability to ensure the power quality provided by the wind turbine employing the OFDM multi-carrier transmission technique associated with an LDPC coding scheme. The satisfactory results of this research endorse the operability and advantages of application of wireless control system for windy plants when some requirements and techniques, based on digital modulation and coding techniques, are employees

Analysis of a Control System for DFIG Wind Generators Based on the Transmission of Power References through a GSM Wireless Network: A Smart Grid Experimental Approach

This work proposes the use of the automatic Short Message Service (SMS) of a Global System for Mobile Communication (GSM) network to transmit the control information to a Doubly Fed Induction Generator (DFIG) of a wind turbine, according to the Smart Grid (SG) concept. In the proposed strategy, the Control Center (CC) can remotely transmit the required power references (active and reactive) to the DFIG controller, in order to manage the power generation of the wind turbine dynamically. The proposed wireless network was developed in a Software Defined Radio (SDR) transceiver connected to an OpenBTS platform. The control information can be directly inserted in the Open Base Transceiver Station (OpenBTS) server (located at the CC) or sent by a wireless device (e.g., mobile phone) connected to the GSM network, and then transmitted to the wireless receiver at the wind turbine. The receiver on the turbine side was developed in a microcontroller board with a GSM card, and the DFIG controller was implemented in a Digital Signal Processor (DSP) board. The results of the tests showed that the DFIG can be satisfactorily controlled according to the power references, considering that they vary at low rates

Integração de três conceitos: função executiva, memória de trabalho e aprendizado

O presente artigo discute o conceito de função executiva enquanto um processo de integração temporal, envolvendo funções como o ajuste preparatório, o controle inibitório e a memória de trabalho. Em seguida questiona o modelo multicomponente de Baddeley para a memória de trabalho e propõe uma nova classificação da função executiva que engloba os modelos de Fuster e de Baddeley. Finalmente revisita o conceito neurobiológico de aprendizado e sugere uma abordagem para se avaliar os déficits de aprendizagem que leve em conta a função executiva como a pedra angular do processo cognitivo