Table 1 Classification of typical PQDs
From: A systematic review of real-time detection and classification of power quality disturbances
Type ofdisturbance | Deviation | Evaluation | Main cause | |
|---|---|---|---|---|
Variations (continuous deviations) | Frequency | – | Imbalance in generation and demand | |
Slow voltage changes | Voltage magnitude | Variation in demand and generation | ||
Waveform distortion | Frequency domain | DC Offset | Electrical machines (transformers, generators, motors), power electronic converters, narrowband PLC | |
Harmonics | ||||
Interharmonics | ||||
Supraharmonics | ||||
Notches | Time domain | Momentary amplitude deviation | ||
Fluctuation | Flicker | Welding machines, multi-cycle control | ||
Imbalance | Symmetrical components | Unbalanced (single-/two-phase) loads or generators | ||
Events (finite deviations) | Rapid voltage changes | Voltage magnitude | Connection of heavy loads, fault clearance, climatic hazards | |
Sags | ||||
Swells | ||||
Interruptions | ||||
Transients | Switching operations, lightning strikes | |||