PMU-based Dynamic Coordinated Voltage Control of a Distribution System with FACTS and Storageless PV Participation

Abstract

With the emergence of smart and/or micro grids as well as increased photovoltaic generators in distribution networks, several power quality concerns have been raised. Among the solutions proposed, recent research interests have be directed to coordinated control with focus in optimal deployment of available FACTS devices with on-load tap changing transformers (OLTCs) for voltage stability. Much of these works have been based on steady state analysis which unfortunately does not depict runtime vulnerabilities in the system. Secondly, while most publications on Phasor Measurement Units (PMUs) have been centered on placement, load modelling, and condition monitoring, relatively little has been done in the area of applying data from PMU for system wide control.
In this study, we use the FPGA-based OP-4500 to perform a real time simulation (software –in-loop) of a PV with PMU and FACTS integrated distribution system. For clear problem definition, we show how the voltage and frequency profiles are affected by the spuriousness of the PV over a 24 hour period based on actual data from sites in Arizona and California. We also show how the varying PV output leads to frequent and lossy switchings of the OLTC. On these grounds, we propose a margin within which the output power of the PV can be optimally tracked so as to contribute to voltage and frequency control even under sag conditions. In addition, an immune learning-based coordinated control is proposed and validated in real-time.