Fixed-Speed Wind Farm Operation Improvement by Using DVR Devices

As the total number of installed wind farms is far from being negligible, an upgrading of their technology is essential to fulfill new interconnection requirements. Power electronics are considered to be a key technology to accomplish this task. In this paper the use of a Dynamic Voltage Restorer (DVR) for the improvement of the ride-through capability of fixed-speed wind farms is analyzed. The contribution of the DVR is analyzed by means of Hybrid real-time tests (with a reduced- scale physical prototype) and offline (full scale) simulations in PSCAD/EMTDC. The study highlights the great contribution of DVRs to the transient behavior of fixed-speed wind farms. However, it is shown their need of an active power handling capacity in order to deal with the active power generated by the wind farm that can not be exported to the grid during the fault In addition to that the limited contribution of the device in normal operating conditions is highlighted due to the admissible voltage range at the wind farm.