Detection of power quality disturbances in microgrid based on generalized morphological filter and backward difference

The microgrid technologies provide an efficient way for various distributed generations connected to the grid. However, the inherent characteristics of distributed generation (DG), the special network topology and the operation characteristics of the microgrid bring unfavorable factors influencing power quality of the microgrid, especially power quality disturbances. In this paper, a new detection method on basis of generalized morphological filter and backward difference is proposed. Firstly, the signal was processed by the first generalized morphological filter which was used for prepositive filter unit, then transformed by dq transformation. And then the second generalized morphological filter with the structuring elements of straight line was used to eliminate the noise. Lastly, the disturbance signal was located by using backward difference. MATLAB/SIMULINK is employed for the simulation studies of the method. The simulation results show that the method possesses the merits of simplicity, speediness and accuracy, and meets the requirement of the real-time cases.