Robust Design of a Solid-State Pulsed Power Modulator Based on Modular Stacking Structure

This paper describes the design of a robust high-voltage solid-state pulsed power modulator (SSPPM), which requires reliable series stacking and driving of a number of semiconductor switches. For voltage balancing against overvoltage during both at transient and at steady-state, the power-cell-based modular stacking structure consists of an energy storage capacitor, bypass diode, and switching device (such as an insulated-gate bipolar transistor or a metal-oxide-semiconductor field-effect transistor (mosfet)). In addition to the reliable voltage balancing of each switching device, the modular power cell stacking structure provides a fault-tolerant design by allowing individual protection circuit for each switching device. In this paper, the inclusion of a compensating third winding is proposed. This compensating third winding solves the voltage unbalance issue, which results from difference of leakage inductance of separate located transformer core, using magnetic flux compensation. A protection method using this compensating winding is also suggested to detect abnormal occurrences in each power cell under operating conditions. Additionally, an arc current protection circuit to ensure continuous operation of the SSPPM is designed. Through simulation and experimental results of tests on the SSPPM with the structure outlined earlier, it is verified that the proposed design can be used effectively, as it exhibits both robustness and reliability.