STATCOM systems in distribution and transmission system applications: a review of power-stage topologies and control methods

Synchronous static compensators (STATCOMs) have been introduced as a member of flexible alternating current transmission systems devices family in both distribution and transmission levels, namely distribution STATCOM and transmission STATCOM, respectively. These compensators have an important role in increasing the power quality in power systems because of having features investigated in various studies and because of the proper implementation of power functions, especially in compensating the voltage flicker. Studies on STATCOM can be categorized in two different parts. The first part is about the various topologies of the electronic converters used in the compensator and different arrangements of the coupling transformers with the network, which can be named as the power part. The second part is about theorizing at the control level, which eventually ends in producing the proper gate signals to control the switching of the electronic power switches in the power part. Considering the fact that two comprehensive reviews on STATCOM have been published in 2002 and 2009, this paper based on the aforementioned categorization reviews the studies fulfilled in the field of synchronous static compensator, especially the relevant studies in recent years published in creditable journals. The paper makes connections among the control methods and compares the ideas about power stage from different perspectives, so that conducted studies will be organized in a systematic order.