Power quality improvement of radial feeders using an efficient method

In this paper, a voltage sag compensation of Point of Common Coupling (PCC) is provided using a suitable hybrid scheme composed of a Fault Current Limiter (FCL) and a Dynamic Voltage Restorer (DVR). Current limiting task is devolved to the FCL, which has a very simple structure, along with a fast and reliable performance, low on-state losses, and low cost. The FCL not only can preserve the short-circuit level of the Distributed Generation grid (DG-grid) in a safe level, but also compensates the voltage sag for the sensitive loads connected to the PCC. The PCC feeders are classified into high-sensitive, low-sensitive, and non-sensitive feeders. In this paper, by profiting from the collaboration of the FCL and DVR in non-sensitive and high-sensitive feeders, respectively, a suitable compensation with minimum cost is suggested. The proposed compensation scheme mitigates the voltage sag and phase angle jump at the PCC. Using this strategy, a cost-effective desirable power quality for the whole loads is assured. Analytical study supported by simulation and experimental results are presented to confirm the effectiveness of the proposed hybrid technique.