Capacitance, dc Voltage Utilizaton, and Current Stress: Comparison of Double-Line Frequency Ripple Power Decoupling for Single-Phase Systems

Double-line frequency ripple power is inherent in single-phase rectifiers and inverters, and, if not managed properly, it can be adverse to system performance at both the ac and dc sides. Therefore, numerous active power-decoupling techniques have been introduced to decouple the double-line frequency ripple power. However, no comprehensive comparisons are available on the permitted minimum capacitance for power decoupling, dc voltage utilization, current stress, modulation complexity, and even application evaluations, except for power rating and component counts. All of these aspects are critical when choosing appropriate power-decoupling techniques for different applications. In this article, the minimum capacitance to decouple the ripple power and the current stress of power devices in the main circuit are derived in light of different voltages across energy storage capacitors. By considering the ripple power paths, we investigate the dc voltage utilization of both the main circuit and power-decoupling circuit. Combined with other features, including component counts and modulation complexity, the overall characteristics of different power-decoupling techniques are compared and summarized to effectively evaluate their performance in different applications.