A cost-effective placement of power quality monitors for harmonic resonance conditions and voltage sags under system uncertainties

This paper proposes a new method for placing power quality monitors (PQMs) to observe harmonic resonance conditions and voltage sags. It aims to achieve a minimum-cost considering system uncertainties while ensuring that the data collected from PQMs is less sensitive to harmonic noise. This work introduces the harmonic noise severity index to facilitate more effective placement of PQMs. The proposed approach identifies and eliminates divergence conditions, addressing a key drawback of earlier approaches to achieve similar goals. A key advantage of the method is that a bus is considered monitored if either the bus itself or any of its neighboring buses is equipped with a PQM, further minimizing installation costs. The validation of the proposed method is carried out on IEEE 30-bus, IEEE 33-bus, and 15-node distribution networks. The results show that harmonic resonance conditions and voltage sags can be monitored with fewer PQMs by applying the proposed method. It was observed that the harmonic noise and voltage threshold values can change PQMs’ locations. The method is applicable to both radial and meshed network configurations under system uncertainties, by using monitor reach areas to calculate the priority of PQM installation. Additionally, the proposed method has the potential to reduce the number of PQMs by 80% and improve system observability by 36%.