I. Introduction
Carrier interleaving is used to obtain multilevel waveforms in cascaded converter architectures such as modular multilevel converters (MMCs), solid-state transformers (SSTs), and numerous other topologies which contain cascaded H-bridges [1]–[5]. This approach is advantageous since it yields high-quality waveforms and relaxed filtering requirements, as well as reduced common-mode noise [6]. As applications evolve to higher voltage levels and topologies become increasingly complex, the number of cascaded converters can become large. In such settings, it is desirable to obtain communication-free implementations where multi-converter systems can be assembled in a modular plug-and-play fashion with minimal wiring between units. Towards that end, we propose a control method that enables decentralized pulse width modulation (PWM) carrier interleaving in cascaded H-bridge systems. After deriving a small-signal model which shows how the cascaded converters interact, we show that the proposed controllers converge to the interleaved state irrespective of how many converters are in the system. The paper concludes with a hardware-in-the-loop (HIL) validation on a digital signal processor (DSP) hardware.