A novel algorithm for voltage transient detection and isolation for power quality monitoring

• A simple algorithm to detect and isolate notches and impulsive transients is presented.
• Its mean operation is a subtraction and it works in the time domain directly.
• This algorithm does not require any tuning process to assure accurate results.
• It is possible to diagnose voltage transients from steady state disturbances.
• Laboratory and industry results validate the algorithm.

Usually the measurement instruments dedicated to power quality assessment contain a transient detection stage that is activated only when it is necessary. However, it is common that such stage does not have the same sampling time than the stage devoted to measurements in steady state such as power factor, harmonic content or RMS values.In this paper, the authors describe a simple algorithm that can detect and isolate notches and impulsive transients from other voltage disturbances with the same sampling time used for measurements in steady state. The merit of this approach is that, if the proposed algorithm is set up in a power quality analyzer (PQA), this device will be able to record all kind of disturbances, the steady state ones using the classical algorithms programmed in the PQA and the transient ones by the approach addressed in this paper, the same sampling time considered for all of them, without substantial increase of the computational effort.The method was implemented in a prototype, and laboratory and industry results are shown. Additionally, operative limitations of the method are discussed.