Series compensation to mitigate harmonics and voltage sags/swells in distributed generation based on symmetrical components estimation

Dynamic voltage restorer (DVR) is a custom power device used for voltage compensation of sensitive loads against voltage disturbances in power distribution lines. In order to ensure constant voltage without any harmonic distortions, the load voltage should follow a reference sinusoidal waveform of desired amplitude. One of the most common control algorithms that are used for the DVR is the symmetrical components method. A control strategy for the DVR based on the symmetrical components method has been proposed for the voltage and power flow control in the wind power supported distributed generation. The proposed method ensures the correction of the positive sequence amplitude during sag and swell, as well as eliminating harmonics distortion of the load voltage. In addition, it also controls the power exchange between the DVR and the distribution system by introducing a symmetrical phase shift into the extracted fundamental component of the load voltage. The results are verified using PSCAD/EMTDC simulation studies.