Power System Harmonics Estimation Using Frequency Adaptive Cascaded Delayed Signal Cancellation Strategy

摘要

Due to increase of distributed generation (DG) and non-linear loads, harmonics in power system is on the rise. The existence of harmonics causes distortions in grid voltage waveforms, degrades power quality, creates ripples, causes overheating and sometimes reduces lifetime of transformers. For this reason, it is necessary to eliminate harmonics from power systems. It is primarily essential to estimate harmonics in a power system for this elimination. Therefore, in this paper, a frequency adaptative stable technique is adopted to precisely estimate the fundamental and harmonics parameters in a single- phase grid voltage system. The technique is formed on 3 consecutive samples (3CSs) and cascaded delayed signal cancellation (CDSC) strategy. This method can track the frequency very accurately and estimate the fundamental and multiple harmonics parameters from the waveform of grid voltage, which is warped by various harmonics. Here under different cases simulations are carried out to analyze the efficiency of the suggested technique. The results of simulation give an idea of the stability and reliability of the whole process.