Power electronics solutions for grid connection of wind farms

In the last years grid integration is a concern of growing interest. In most countries, transmission system operators are redefining the grid codes that establish grid connection requirements of wind turbines. These grid codes are getting more and more demanding, especially regarding to fault ride through capability and reactive power control. This work studies the current solutions to overcome these new rules. It analyses differences between the three main wind turbine topologies and their difficulties to meet grid codes. Most solutions are based on additional equipment like crowbars for fault ride through voltage sags or STATCOM for injecting reactive power. But they do not manage to fulfil completely the new rules and result quite expensive. Moreover, for the moment, there is no solution for fixed speed wind turbines to overcome a grid fault. This work proposes a new alternative for these old wind farms that although expensive, allows their operation within the most demanding rules. Anyway, we consider that in the near future, the most suitable topologies will be the ones based on full power converters that as explained in the paper, have fewer difficulties to overcome the new grid codes.