A novel adaptive flicker measurement technique

An adaptive measurement method is presented for the estimation of interharmonic components causing light flicker. The method provides an alternative technique for the estimation of sinusoidal components of unknown frequency, where well-known methods of processing of stationary signals such as the DFT-based techniques may fail. The proposed technique is based on a recently developed sinusoid-tracking algorithm that is capable of tracking time-variations of the parameters of a nonstationary signal such as its frequency and amplitude. The preliminary stages of demodulation and bandpass filtering combined with dynamic adjustment of the parameters of the sinusoid-tracking algorithm allow for effective estimation of the components that may cause light flicker. The structure of the proposed flicker measurement technique is composed of two parallel branches, each finding the amplitude and frequency of an interharmonic component. Presented computer simulations demonstrate its performance while laboratory experiments verify its in situ functionality. Given the low complexity of the proposed technique, it is well-suited for real-time applications.

► Flicker is a power quality issue that can be difficult to measure. ► There is increasing presence of distributed generation on the distribution system. ► A new method of measuring flicker uses the sinusoidal tracking algorithm (STA). ► The STA algorithm tracks non-stationary signals, where other methods may fail. ► The low complexity of the method makes it suitable for real-time applications.