State Estimation and Real-Time Cyber Secure Power Factor Correction for Utility-Scale DERs

Reactive power (Q) is typically supplied by capacitor banks in conventional electric power distribution systems. However, the increasing use of distributed energy resources (DERs) complicates the ability to regulate voltages using conventional methods. This creates a need for secure network controls for coordinating reactive power compensation. Inverters presently used with wind and solar DERs have the ability to inject Q but do not have real-time information of the amount of Q consumed in the distribution system. In this paper, a combination of a tertiary droop control assisted by an ac-based state estimator for a ring/mesh distribution system is designed to control a 12.47kV DER to supply the required Q. Detailed simulation results show that such a combination can control DERs to keep the power factor greater than 98% at remote distribution substations in a quasi-real-time fashion. The results suggest that the future of distribution management systems (DMS) should follow the same trends in transmission-level energy management systems (EMS) in controlling DERs.