Common Mode Voltage Minimization for Generalized Dual Inverter-Fed Aircraft Starter/Generator: Realization and Sub-Load Asymmetry Influence Analysis

In multistages aircraft starter/generator system, the main machine (MM) and main exciter (ME) are fed by a generalized dual-inverter configuration, allowing for common-mode voltage (CMV) elimination. However, the distinction in load impedances and voltage requirements between the two subinverters has evidently contributed to the subload asymmetry, which may impair the suppression effect of system common mode (CM) noises. This article presents a CMV minimization method for the generalized dual-inverter application. The available freedom, such as the selection and action sequence of voltage vectors, is appropriately arranged in the suggested implementation to eliminate the total CMV, restrict the sub-CMVs and fulfill the voltage requirements of subinverters all at the same time. In the meanwhile, a theoretical study is performed to evaluate the CM noise features of zero CMV technique in the generalized dual inverter-fed system. In the situation of subload asymmetry, the premise and main influence element for CM noise reduction are assessed. Finally, these findings are verified by simulation and experiments.