Static Synchronous Series Compensator for active power flow control during unconventional operating conditions

The aim of this paper is to present reconfiguration schemes for a 3-Level Neutral Point-Clamped 48-pulse Static Synchronous Series Compensator under unconventional operating conditions, e.g. operation with an incomplete topology or a system unbalance. Combinations of converter modules that generate suitable injection voltages for both conditions are obtained. Calculation of the conduction times for each module minimizes voltage harmonics when one of them fails. Moreover, line-frequency and Pulse Width Modulated switched modules are combined when an unbalanced condition is detected. Simulations are carried out that confirm the validity of the proposal.