DYNA JOURNAL ENGINEERING

Key words:

modular multilevel converter (MMC), non-linear vector current source, ultracapacitor, wave turbines, convertidor modular multinivel (MMC), fuente de corriente vectorial no lineal, ultracondensador, turbinas de onda.

Article type:

ARTICULO DE INVESTIGACION / RESEARCH ARTICLE

Section:

RESEARCH ARTICLES

This article focuses on smoothing the large power peaks that wave energy converters (WECs) inject into the electrical grid. The study is carried out for a single WEC where the generated power is delivered to the grid by means of a power converter. Two different measures have been considered to improve the power quality of the grid connection. Firstly, the electronic converter has been chosen a modular multilevel converter (MMC) to allow replacing the standard high voltage capacitors of the DC link by low voltage ultracapacitors distributed across the modules of the MMC. Secondly, the MMC is controlled using a non-linear vector current control. The results show that the power delivered to the grid becomes approximately constant when using ultracapacitors. Furthermore, the non-linear vector current source provides the grid connection converter with the necessary fast dynamic response to avoid large variations in the DC voltage.
Keywords: modular multilevel converter (MMC); non-linear vector current source; ultracapacitor; wave energy converter (WEC).