Design of gate trigger unit for voltage reinjection multilevel VSC converter with cascaded H bridges

A gate fire unit for voltage reinjection multilevel VSC converter with cascaded H bridges, which operates under the condition of high voltage and high capacity, is designed. During the design of fire unit, a lot of key problems to be paid attention to in practice, such as switching pattern selection, how to synchronize with power grid, edge state judgment and so on, are analyzed in detail, and the simulation that takes the application of the designed gate trigger unit in STATCOM as background is performed. Simulation results show that the designed gate fire unit based on reinjection multilevel converter possesses good steady-state response and dynamic response.