Photovoltaic power plant as FACTS devices in multi-feeder systems

This paper illustrates possible configurations for a large-scale photovoltaic power plant (PV), to operate as a FACTS (flexible AC transmission system) device in addition to operating as a source of renewable power generation. The inverters in PV plant are reconfigured in such a way that two or more distribution networks/feeders are interconnected. This newly developed system where inverter modules are connected in back to back is addressed as Interline-PV (I-PV) system. Based on the inverter reconfiguration, three distinct topologies can be realized, namely, (i) Shunt I-PV, (ii) Series I-PV and (iii) Shunt-Series I-PV. These configurations enable the PV power plant to operate through two adjacent power system networks/feeders. The proposed configurations of PV system can act as Inter Line Power Flow controller (IPFC), Static Synchronous Compensator (STATCOM), or Unified Power Flow Controller (UPFC). The new configurations expand the role of PV plant to regulate the network/feeder voltages, support active and reactive powers and enhance the overall dynamic performance of both the feeders. This paper discusses the advantages and limitations of each of the I-PV systems. A simulation study is done to illustrate some of the benefits offered by I-PV systems.