Accuracy Of Harmonic Detection Research Articles

Improved harmonic detection method based on ip-iq theory

Based on the traditional ip-iq harmonic detection theory, the accuracy of harmonic detection is easily affected by the phase-locked loop (PLL) output phase error, and the single low-pass filter (LPF) detection accuracy and filtering effect cannot be simultaneously. In this paper, an improved harmonic detection method based on the second-order generalized integrator-frequency locked loop (SOGI-FLL) technique is proposed to generate sine and cosine signals with the same frequency as the grid voltage; The traditional low-pass filter and average filter are used in series to improve the response speed and accuracy. Through theoretical analysis of the improved harmonic detection method and simulation in MATLAB environment, the theory and simulation results prove the effectiveness of the improved method.

Study on improved Ip-iq APF control algorithm and its application in micro grid

In order to enhance the tracking velocity and accuracy of harmonic detection by ip-iq algorithm, a novel ip-iq control algorithm based on the Instantaneous reactive power theory is presented, the improved algorithm adds the lead correction link to adjust the zero point of the detection system, the Fuzzy Self-Tuning Adaptive PI control is introduced to dynamically adjust the DC-link Voltage, which meets the requirement of the harmonic compensation of the micro grid. Simulation and experimental results verify the proposed method is feasible and effective in micro grid.

Method of Wavelet Denoising in Harmonic Detection

Harmonic detection is an important step in grid harmonic status evolution and suppression measures implementation. While it’s accuracy is interference to the noise in the power grid. The different characteristics of signal and noise in the wavelet transform are proposed firstly, and the method of soft threshold de-noising based on wavelet multiresolution is analyzed in the paper. Using the method, the noisy harmonic signals in the power grid are processed and the de-noisy signals are analyzed by Fourier Transformation (FT) to obtain the contents of each harmonics. The simulation results show that the harmonic containing rate is close to the original signals after de-noising by WT. That is the method reduces the interference of noise and the accuracy of harmonic detection is improved.