Intelligent protection for embedded generation using active impedance estimation

With the increased use of distributed generation (DG) such as wind generation with characteristics of intermittence and fluctuation, the ability to maintain a reliable and a secure supply with high power quality in power systems is becoming more challenging. The increased use of power electronic converters within loading systems causes further problems for power quality – harmonics 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 presents a method for real-time power system impedance estimation, which has the potential to enhance the performance of power quality devices such as STATCOM to provide additional capability for grid support and more intelligent protection. Experimental results verify the identification method.