Validation of the Plug-and-Play AC/AC Power Electronics Building Block (AC-PEBB) for Medium-Voltage Grid Control Applications

As ac-to-ac power conversion becomes increasingly important in applications such as grid power control and motor control, demand for a plug-and-play converter has increased. Traditional voltage-source-inverter-based ac-to-ac power converters such as the back-to-back converter require dc-link capacitors that limit their reliability or significantly increase their size and cost. This paper examines a plug-and-play concept for achieving ac-to-ac power conversion via the direct-ac/ac power electronic building block (AC-PEBB). The AC-PEBB is a compact self-contained cell requiring no intermediate energy storage. It can be used in a variety of ac/ac power electronic applications such as matrix converters and controllable network transformers. This paper details the design of an 800-V 100-A AC-PEBB prototype to be used in a 13-kV 1-MVA application. Successful test results using several AC-PEBBs in a variety of configurations are demonstrated at up to 11 kV and 600 kVA.