Transformer-less based solid state transformer for intelligent power management

Future electricity grids will integrate large scale renewable sources such as photovoltaic (PV) and wind farms. The intermittent nature of energy generation from such sources creates challenges to the electricity grid. Advanced intelligent transformers will be needed to achieve proper operation of the future smart grids besides enhancing power quality and securing energy supply to critical loads. These transformers must be able to provide intelligent power management as well as subsidiary services. This paper proposes a transformer-less based solid state transformer (TL-SST). The TL-SST performs better than the traditional auto-transformer used in the industrial application. It has several advantages over the traditional one, as it enhances power quality compatibility between the grid and the loads or vice-versa. The TL-SST is able to provide ride through capabilities, which can isolate short term disturbances from the grid to loads and vice-versa. This paper describes the operating principle and control of the proposed TL-SST. The power quality enhancement features will be validated under various grid and load conditions using computer simulation.