Operating region and control for power converters connected to a variable frequency and amplitude voltage grid supply

Power converters have been widely used in industrial applications as parallel and series compensators, UPQCs, and STATCOMs. These electronic devices can also be utilized on weak-grid or micro-grid systems, where both the supply voltage amplitude and frequency, may vary considerably from the nominal values. Micro-grid and weak-grid systems are commonly associated to distribute non-conventional power generation sources, where the voltage and frequency deviation are as a result of unbalances between generation and consumed power. This work studies and develops a Series Compensator control for a non-constant power supply. The study is focused on the rectifier control in order to get a stable closed loop system for sags and swells as well as frequency variations. In addition, an operating region study is performed in order to evaluate the capabilities and to find the maximum range of frequency variation tolerated by this topology. Finally, simulated results show the feasibility of the proposed control for a wide frequency and voltage variation.