Determining the quality of the electricity supply is essential to know the proper functioning of the electrical system at all levels. Depending on the point of the electrical system analyzed, the information obtained and its relevance change. It is therefore intended to determine the adequacy of the voltage and current waves to their nominal prescriptions. Currently, the signal processing techniques most used today are being investigated. Later on, it is intended to propose techniques that, even though they exist in other fields, have not been used in the quality of electricity supply.