Investigations on Reactive Power and Dead Time Compensation for a Double Active Bridge with a Planar Transformer

Abstract

In the future, the power system will be a set of intelligent grids (smart grids) with the generation close to the demand (micro grids). The ultimate goal will be to accomplish most of the energy demand with clean and renewable sources. The problem of this energy sources is that they are volatile, and thus the generation may not match with the demand in some instants. In order to solve this, energy storage systems are required to absorb the extra power when there is more generation than demand, and releasing it in the other case. The objective of this thesis is to study the interconnection between these grids and the energy storage with an isolated power converter. A first overview around the different possible converters is covered in order to justify the selection: a dual active bridge (DAB). The behaviour of the DAB was then explained under different situations. Especial interest is paid in the effect of the dead time in the behaviour of the converter and the excessive reactive power. Finally, a control of the power flow in this converter is tested with a variable load. It is also tested an algorithm to compensate the effect of the dead time.