A flexible DG interface based on a new RLS algorithm for power quality improvement

Distributed generation (DG) exists in distribution systems and is installed by either the utility or the customers. This paper proposes a novel utilization of the existing DG interface to not only control the active power flow, but also to mitigate unbalance, harmonics and voltage flicker, and manage the reactive power of the system. The proposed flexible distributed generation (FDG) is similar in functionality to FACTS, but works at the distribution level. Moreover, a novel recursive least square (RLS) structure is presented. The new structure is applied to multi-output (MO) systems for parameter tracking/estimation, and is called MO-RLS. It is dedicated to symmetrical components estimation. An innovative processing unit-based RLS is investigated to deal with unbalance, harmonics, and reactive power compensation. In addition, this paper portrays a technique for flicker mitigation based on the RLS algorithm for instantaneous tracking of the measured voltage envelope. One advantage of the proposed control system is its insensitivity to parameter variation, a necessity for distribution system applications. Simulations of the suggested FDG based control algorithm are conducted to evaluate the performance of the proposed system.