Comparison of detection methods for power quality in micro-grid

The micro-grid brings benefits for the economic development, but the transient power quality disturbances and harmonics generated by distributed power and grid-connected are inhibited to the development of micro-grid system. Detection and identification of these transient power quality disturbances are important. To circumvent this problem, the paper discusses the methods of power quality detection in frequency domain, mainly the Fourier transform, wavelet transform, HHT, S-transform and atomic decomposition as the main methods. It compares the advantages and disadvantages of these methods and analysis the power quality disturbance problems in micro-grid. By theoretical analysis and MATLAB simulation, it can be concluded that S-transform has high accuracy and well noise immunity in power quality detection, which provides an important reference to solve the problem of the micro-grid power quality disturbances.