Minimal energy control for a dynamic voltage restorer

Power quality measurement projects have reported that voltage sags are the most frequent disturbances. Dynamic voltage restorers (DVRs) emerged as an effective and economic solution for this problem. Control algorithms for a DVR can be categorized into an in-phase control method and a minimal energy control method. This paper exploited various operation modes and boundaries such as inductive operation, capacitive operation, and minimal power operation. The power flow of a DVR is analyzed both in minimal energy control method and in-phase control method. The operation of the minimal energy control method is compared with that of the in-phase control method.