In this paper, a high voltage power supply based on an asymmetric multilevel cascaded bridge converter is presented. The required power supply shall be able to reach output voltages up to 30kV with rising and falling times shorter than 10 microseconds. Each module of the converter is supplied by an insulated dual bridge DC/DC converter allowing an independent DC-link voltage control with bidirectional capability. In order to validate the principle, a small scale prototype has been successfully built and tested.