An interleaved converter consists of multiple phases operating out of phase with the well known benefits of reduced input output current and ripples, improved efficiency and better thermal performance. When the interleaved converter is connected to a constant power load, its negative incremental impedance characteristics leads to instability. This leads to an increased oscillation in the DC link voltage and the source current which is interfaced with the interleaved converter. In this manuscript, a robust control consisting of the sliding mode control is proposed to damp the oscillations due to CPL and maintain the DC link voltage and source current within the permissible desired limits. The proposed sliding manifold consists of the power error terms and a voltage error term. The proposed control performance is validated through simulation and experimental results on a 500W three phase interleaved boost feeding a buck converter fed resistive load setup.

The three-level submodule (3L SM) has emerged as a viable alternative to the conventional half-bridge submodule in modular multilevel converters (MMC), primarily due to its reduced footprint. Despite this, there has been no in-depth exploration of MMC topologies utilizing 3L SMs, particularly in the context of motor drive applications. The 3L SM features two capacitors, and the MMC relies on a cascade connection of multiple 3L SMs per phase, necessitating voltage-balancing control for these capacitors. This paper introduces a voltage-balancing control strategy for multiple capacitors, incorporating high-frequency voltage and circulating current injections to ensure optimal performance in low-speed motor drive operations. The voltage commands are normalized and compared with phase-shifted carrier (PSC) PWM triangular waveforms to generate gating signals. The proposed voltage-balancing control method has been validated through a 4160-V/1-MW simulation model using a hardware-in-the-loop (HIL) system.