Then the novel SDPQD detection and classification method based on complex wavelet and S-transform respectively is proposed, and the S-transform-based expert system for voltage dips (sags) classification is presented.

• 在此基础上，分别提出了基于复小波变换的短时电能质量扰动检测方法，基于S变换的扰动分类识别方法和电压凹陷分类分析专家系统。