Custom power active transformer for flexible operation of power systems

Resumo

This PhD dissertation proposes a new transformer, i.e., the Custom Power Active Transformer, characterized by a specific design of its magnetic circuit and auxiliary windings which allows shunt and series compensation to the power system in a single monolithic transformer. Such auxiliary windings are regulated using power converters based on power electronics. The power electronics converters are controlled based on the required added services to the power system which includes power flow control between different areas, power quality improvements, inertia emulation and several other services that are applicable through power electronics converters. The objective of the proposed transformer is to enable integration of power electronics to a transformer structure which empowers the transformer with added services aiding the transformer operation and power system flexibility. Single-phase and three-phase structures have been modelled, simulated and experimentally tested through a prototype setup and real-time simulation. The presented structures have been demonstrated to operate for power flow and power quality control applications to reveal the applicability of the proposed transformer for a wide range of compensation systems. Furthermore, benefits of the combined structure, operating limits and selection consideration are revealed. Finally, this PhD dissertation presents the expected prospects of the Custom Power Active Transformer and the possible research areas that would require development for its enhancement.