Combine DVR in DFIG Wind Turbines in Network Oscillations

In the recent years using renewable energies including wind energy is increasing significantly. Different systems have been presented for converting wind energy to electrical energy, the most common of which is Double Fed Induction Generator (DFIG). These types of generators are equipped with two electronic convertors that are able to control the absorbed reactive power from the network and voltage drop in the line. Of course at the time of fault in the network it is possible that these convertors would be damaged because of passing high current. Thus, another equipment is used which is named Crowbar that conducts ,the current to resistances at the time of fault and prevents passing high currents from the convertors. Of course when crowbar is inserted in the circuit DFIG will be changed to an inductive machine and will absorb the intense reactive power from the network and voltage drop in the line. Thus, for solving this problem this paper suggests using a Dynamic Voltage Restore (DVR) for controlling the current and voltage in the line. By using DVR, electronic convertors will remain in the circuit at the time of fault, thus the machine will remain as DFIG and as a result the absorbed reactive power and voltage drop in the line will be decreased to zero. The results achieved from simulation on a 2 MW wind turbine using MATLAB software proves that the suggested method is significantly effective in comparison with Crowbar method

Keywords:

Power Quality , DVR , Crowbar , DFIG Wind Turbines