New Control Strategy Extends AC/DC Rectifier Lifetime

Researchers have proposed a control strategy for AC/DC rectifiers designed to reduce aging mismatch between phase legs. The study introduces a preselected voltage vector strategy integrated with model predictive virtual-flux-based direct power control. The primary objective of this approach is to reduce the aging mismatch between the phase legs of the rectifier, specifically targeting the leg with the highest aging state to increase its operational lifetime. By focusing on the most stressed component rather than all three phases simultaneously, the method aims to achieve a more balanced degradation profile across the power electronics system.

The proposed technique is derived from the principles of discontinuous pulse-width modulation. It determines specific clamping regions within the phase leg that exhibits the highest aging state. By identifying these regions, the strategy selects corresponding voltage vectors that maintain the current status of the power switches. This selection process is designed to reduce switching losses, which directly leads to decreased thermal stress on the components. This reduction in thermal stress results in an increase in the lifetime of the AC/DC rectifier.

A key distinction of this per-phase technique is its targeted approach to thermal management. Unlike other conventional approaches that attempt to minimize switching loss and thermal stress across all three-phase legs simultaneously, this method focuses exclusively on relieving the thermal stress of the single leg with the highest aging state. The result is a reduction in the rate of aging for the critical leg, thereby prolonging the functional life of the entire rectifier assembly.

The study also addresses the performance of the rectifier under non-ideal power supply conditions. The proposed approach guarantees the performance of line current harmonic distortion even when the supply voltage is harmonically distorted. This performance is achieved through the use of a virtual flux vector.

The proposed technique is straightforward to implement in practical applications. It does not require any extra hardware.

To validate the effectiveness of the proposed method, the researchers conducted both simulations and experiments. In addition to the new technique, they implemented and tested conventional model predictive direct power control and conventional model predictive virtual-flux-based direct power control methods. The performance of these three control schemes was evaluated and compared to assess the accuracy and effectiveness of the proposed approach.

Subject of Research: Control strategy for AC/DC rectifier lifetime extension

Article Title: Preselected voltage vector strategy integrated with virtual flux-based predictive direct power control for AC/DC rectifier

Article References: Nguyen-Minh, H., Nguyen-Minh, T., Hoang, M. H., & Ta, D.-T. (2026). Preselected voltage vector strategy integrated with virtual flux-based predictive direct power control for AC/DC rectifier. Scientific Reports. https://doi.org/10.1038/s41598-026-76392-1

Image Credits: AI Generated

DOI: 10.1038/s41598-026-76392-1

Keywords: AC/DC rectifier, voltage vector strategy, virtual flux, predictive control, direct power control, phase leg aging, thermal stress reduction, switching loss, discontinuous pulse-width modulation, power electronics, lifetime extension, harmonic distortion, model predictive control, clamping regions, power quality, component degradation, industrial power conversion, electronic reliability, control algorithm, experimental validation