Abstract
This paper presents and discusses the concepts of a gapless power quality disturbance recorder (G-PQDR) and a novelty detector. In the G-PQDR, power signals are divided into continuous frames, and the energy difference between a current frame and a reference frame is used for comparison. If the current frame differs from the reference frame, it is recorded and becomes the new reference; otherwise, the frame is discarded and only the frequency of the fundamental component is stored. The G-PQDR is capable of detecting and recording both previously known PQ disturbance waveforms and those not yet observed in power systems, thanks to the novelty detection concept. This feature is particularly important in the context of smart grids, where hidden disturbances can be identified using this methodology. To ensure efficient data storage by minimizing the volume of stored data, the G-PQDR employs both lossy and lossless compression techniques. This paper describes the complete process of detection and compression and compares the performance of the proposed method with that of a commercial power quality data recorder. Additionally, details of the prototype implementation are presented.