An Inductorless Direct-injection Power Control Circuit for the Distribution Grid

This paper presents an inductorless direct-injection power flow and quality control topology. The circuit removes any bulky low-frequency transformer and includes a shunt active front end and high-frequency links that powers a series floating module per phase. These floating modules are connected in series with each phase and omit any ground connection, thereby only dealing with a small portion of the voltage difference. Unlike other low-voltage power controllers with full converters, the direct-injection circuit presented here does not need to handle full power, which allows for the utilization of low-voltage high-current GaN transistors. As a result, high-frequency switching can be adopted, and the conventional filtering inductor in series can be replaced by parasitic inductance naturally occurring between cables. Overall, the circuit is exceptionally small and compact by employing low-power components and omitting line transformers and inductors.