Power System Impedance Estimation for Improved Active Filter Control, using Continuous Wavelet Transforms.

As the composition of power systems change, with the increased use of distributed generation, the ability to maintain a secure supply with high power quality is becoming more challenging. The increased use of power electronic converters as part of loading systems provides further problems for power quality by introducing harmonics, voltage dips, etc. It has been shown that knowledge of power system parameters (particularly the net power system impedance to source) at any instant in time is central to addressing these problems. This paper develops a method for ultra-fast real-time on-line power system impedance estimation, which has the potential to enhance the performance of power quality devices, distributed generation and power system protection. Experimental results verify the identification method and demonstrate its use in an active power filter