The book presents a methodology for detection and quantification disturbances of power quality energy. Digital signal processing (DSP) is applied to simulated and measured disturbances. The use of DSP enables the construction of digital filters for the detection of events, and the estimation of the frequency of voltage and current signals. The proposed algorithm quantified the disturbances in according with standards. The program developed was tested using simulated disturbance for its validation. Field measurements were used to assess the robustness of the algorithm against signal noise and other disturbances. This research presents effective and practical software that can be used to develop a new device for measuring the disturbances of Power Quality Energy. The results obtained through the analysis of data (simulated and measurements) validated the proposed algorithm.