The solid state transformer (SST) is a high-frequency power electronic converter as a distribution power transformer. A common three-stage configuration of an SST consists of ac-dc rectifier, isolated dc-dc dual-active-bridge (DAB) converter, and dc-ac inverter. This work addresses the controller design issue for a dc-dc DAB converter when driving a regulated single-phase dc-ac inverter. Since the switching frequency of the inverter stage is much higher than that of the DAB stage, the single-phase inverter is modelled as a 120-Hz current sink. The effect of 120-Hz current by the single-phase inverter is studied. The limitation of PI-controller, low gain at 120 Hz, is investigated. Two methods are proposed to improve the regulation of the output voltage of DAB converters. The first one uses a bandstop filter and feedforward, while the second method uses an additional proportional-resonant controller in the feedback loop. Theoretical analysis, simulation and experiment results are provided.
- Closed-Loop Control,
- Dual Active Bridge Converter,
- Feed-Forward,
- Proportional-Resonant Controls,
- Single-Phase Inverters,
- Solid State Transformer (SST),
- Electric Rectifiers,
- Energy Conversion,
- Exhibitions,
- Power Transformers,
- DC-DC Converters,
- Feedforward,
- Proportional Resonant Control,
- Single Phase Inverter,
- Inverters,
- Feedforward Neural Networks,
- Gain,
- Capacitance,
- Harmonic Analysis,
- Voltage Control,
- Frequency Control,
- Rectifying Circuits,
- AC-DC Power Convertors,
- DC-AC Power Convertors,
- DC-DC Power Convertors,
- Invertors,
- Power Filters,
- Proportional Control
Available at: http://works.bepress.com/jonathan-kimball/26/