Unlike a static synchronous series compensator (SSSC) or a unified power flow controller (UPFC), which can control the power flow in a single transmission line, the interline power flow controller (IPFC) can address the problem of compensating multiple transmission lines simultaneously. The IPFC employs a number of dc-to-ac converters linked together at their dc terminals, each controlling the power flow of a different line, in conjunction with its series coupling transformer [22]. An IPFC with p series converters will have (2p − 1) degrees of freedom—2 degrees of freedom for each of the (p − 1) converters and 1 degree of freedom for the remaining one (because the real power exchange among the p series converters is balanced at all times). Usually, these 2 degrees of freedom correspond to the active and reactive power flow in a line.