Since the application of the similarity of module time-frequency matrixes by S-Transform to identify different duration power quality disturbance needs different dimensions of the standard templates, module time-frequency matrix scale-transformation based on bilinear interpolation is used to construct standard templates for different duration disturbances, which reduces the template number. Based on maximum similarity principle, the identification system only needs simple arithmetic operations to classify disturbances without any classifier. The proposed classifying process is concise and effective. Simulation results show that this recognition system has good noise robustness and can classify different duration disturbances well and truly.
