A new power quality deviation index based on principal curves

• The principal curves technique is used to construct a new PQ deviation index.
• The proposed PQ index is general, i.e., it can be used for any type of disturbance.
• The PQ index measures how much the actual voltage is deviated from the ideal voltage.
• The index can also be used for disturbance detection and classification purposes.
• In the operational stage, the PQ index is achieved by simply computing a distance.

In this paper, a new power quality deviation index based on principal curves is proposed. The index provides a quantitative measure, which gives an idea of how much the monitored electrical signal has deviated from the nominal one. Differently of existing indices, the proposed index is a general index, i.e., it can be used for any type of disturbance in the monitored signal. In addition, the proposed index is used to perform a direct approach for detecting disturbances in power signals. This approach is able to detect the beginning and localize the disturbance by analyzing non-overlapping signal windows of one cycle of the fundamental component, leading to a simple method in terms of computational complexity.