Coherence‐based automatic power factor correction (APFC) algorithm for power grids

A power factor correction (PFC) plays a major role towards the improvement of power systems quality and stability, as well as protection and control systems performance. This paper presents a novel method for automatic power factor correction (APFC) based on the coherence approach. In this method, the original power factor and the required reactive power compensation can be determined using the cross-coherence coefficients evaluated between voltage and current signals. Beside auto-coherence coefficients are useful for detecting the fault/unbalance conditions in power systems. The proposed algorithm prevents the PFC process in the events of over-compensation and abnormal events. In addition, new proposed operating characteristics for PFC, based on the coherence coefficient limits, are developed. Extensive simulation results of the proposed method are included and its accuracy and feasibility can be verified. Compared with the conventional PFC, the coherence-based PFC is easy to control, and the power factor is nearer to unity can be obtained, where its performance accuracy is greater than 99.4%. The proposed method is characterized by being simple, fast and reliable, and it can be implemented practically. Its sensitivity and security is controllable via selecting coherence setting values.