Grid Impedance Monitoring System for Distributed Power Generation Electronic Interfaces

This paper proposes a grid impedance monitoring system for distributed power generation electronic interfaces. The system estimates the grid equivalent impedance and voltage source from the voltage measurements performed at the point of common coupling. The estimation algorithm is based on a recursive least-squares algorithm implemented in the complex field. Simultaneously, the system evaluates the quality of the estimation, minimizing its influence on the grid and detecting islanding situations. The proposed system performance has been evaluated under experimental testing.

I. Introduction

The Global increase in energy consumption and the fast development of highly populated countries are unmasking problems in the current power system paradigm. Recent blackout problems in both the U.S. and Europe are focusing the point of view of researchers and governments toward a distributed power system model. In this new model, distributed power generation systems (DPGSs) such as wind turbines, photovoltaic (PV) systems, and microgas turbines will play a more important role (Fig. 1). Fig. 1.

General situation diagram.