A New Method for Assessing Ancillary Service of FACTS in Congestion Management

Managing transmission congestion in an unbundled electric power system poses a challenge to ISO. Flexible AC transmission system (FACTS) can provide ancillary services to solve congestion problem. However, how to assess the ancillary service provided by FACTS devices and allocate the charge is a key issue need to be solved. This paper proposes a new method for assessing ancillary service of phase-shifter used in congestion management, which is based on a new electrical dissecting method. Considering of that the FACTS devices are used to relieve congestion and reduce energy price for consumers, it is reasonable to allocate the utilization charge among consumers or suppliers who caused the congestion. And the electrical dissecting method is used to obtain responsible factors of consumers or suppliers causing congestion. Example shows the method is effective and correct, which can not only provide accurate electrical information to assess ancillary services of phase-shifters, but also provide useful reference to the assessment of ancillary services with other FACTS devices.