Power-Quality Improvement Using Wiener Filters Based On a Modular Compensating Strategy

This paper introduces a new modeless modular compensating strategy to extract and mitigate power-quality (PQ) disturbances. The main advantage of this strategy is that it does not require any model or state-space formulation to extract the disturbances, such as the other commonly used state-space techniques. In addition, it is very simple for practical implementation compared to the time-domain and frequency-domain methods. The proposed strategy depends on recursive implementation of the Wiener filtering theory. The suggested strategy is validated by digital simulation results on the most common stationary and transient PQ problems.

I. Introduction

The deregulation era has stipulated a specific quality of power that is delivered to loads. Power-quality (PQ) problems have become the focus of interest of the operators in utilities due to the negative impact of their disturbances on industrial and domestic equipment. PQ problems can be classified into voltage-quality problems and current-quality problems [1]. Voltage and current harmonics are the most common stationary PQ problems in any distribution system; they always cause malfunction in sensitive equipment. Voltage and current fluctuations, (flicker), become common in industrial systems. If the flicker level is increased above a certain threshold, the other customers in the same system become irritated. Voltage sags and swells are the most severe PQ problems because they cause interruption of production lines in industrial plants. The previous drawbacks shed light on the importance of the mitigating processes for PQ problems.