Voltage Compensation Using UPQC For DFIG Wind Turbine Low - Voltage Ride - Through Solution

This paper describes the problem of voltage sags and swells and its severe impact on sensitive loads and introduces a new solution for doubly fed induction generators to stay connected to the grid during voltage sags. The main idea is to increase the stator voltage to a level that creates the required flux to keep the rotor side converter current below its transient rating. To accomplish this goal, a series compensator (UPQC) is added to inject voltage in series to the stator side line. The series converter monitors the grid voltage and provides compensation accordingly to accomplish this aim. To keep the current at its minimum, a control strategy has been developed to keep the injected voltage and line voltage in phase during and after the fault. Comprehensive results are presented to assess the performance of each device as a potential custom power solution.