Online tracking of voltage flicker for inverter-based distributed generation using Teager energy operator

摘要

Nowadays, increasing nonlinear loads as well as distributed generation (DG) sources, which are some of these types, not only cause a wide range of voltage fluctuations, but also make it difficult to control the DG sources to produce proper output. Hence, it is necessary to use an approach that evaluates and tracks the voltage fluctuations, and also to have an output with optimal accuracy and smoothness that is suitable for control of DG sources. This paper presents a Teager energy operator (TEO)-based approach to track and detect the voltage fluctuations in distribution networks in the presence of the inverter-based DG and nonlinear load that eliminates as much as possible distortion and unwanted signals from the voltage flicker signal. This hybrid algorithm is able to track accurate the amplitude variations of voltage disturbances in industrial systems. To attain this aim, a suitable combination of the TEO and a relevant filter set is adopted. Simulations for a mathematical fluctuation waveform and the grid-connected inverter-based DG using the proposed method are conducted and results are compared with each other to evaluate their performance. Simulation results for different voltage fluctuations validate that the new approach is accurate and smooth in tracking the voltage fluctuations.