Hybrid Transformers for Power Quality Enhancements in Distribution Grids – Comparison to Alternative Concepts

Abstract:
The increasing integration of renewable energies deteriorates the power quality of the distribution grid. Actively controlling the grid voltage is an effective alternative to reinforcing cables and overhead lines. Combining a conventional transformer with a fractionally rated power electronic converter, the hybrid transformer allows a highly dynamic control of voltage, active and reactive power while utilizing the high efficiency and reliability of conventional transformers. This paper compares the functionality and performance of hybrid transformers to alternative solutions and states uninvestigated aspects which need to be addressed before a widespread application of power electronicsbased systems can be expected.