Mobile QR Code QR CODE : The Korean Institute of Power Electronics
Title High Precise Measurement of Grid-Connected Inverter using DFT
Authors Sang-Hyeok Lee ; Feel-Soon Kang ; Sang-Hun Lee ; So-Eog Cho ; Tae-Won Lee ; Sung-Jun Park
DOI 10.6113/TKPE/2012.17.2.93
Page pp.93-98
ISSN 1229-2214
Keywords Discrete Fourier Transform; Precise Measurement; Harmonics; Filter; IDFT
Abstract A precise measurement of the grid voltage is one of the essential techniques, which is required to connect a renewable energy to the grid. In general, when a filter is used to eliminate unnecessary harmonics and noises, a signal is distorted by phase delay, amplitude attenuation, and other distortions. And the response characteristic of a controller is directly affected by bandwidth of cut-off frequency of the filter. To alleviate this problems, we propose an effective algorithm based on DFT(Discrete Fourier Transform) instead of approaching the filter application. The proposed algorithm ensures high precise measurement of the grid voltage because it can extract the fundamental and harmonics from the raw signal without any distortions. The high performance of the proposed algorithm is verified by PSIM simulation and experiments of Grid-Connected VSI.