Active Filtering-Based Decoupling of Fluctuating Power in Single-Phase Converters

Shaikh Zubair A. R. — 2026-08-19

Single-phase AC/DC and DC/AC converters are widely used in renewable energy systems, electric vehicle chargers, uninterruptible power supplies, and distributed generation applications. Despite their widespread adoption, these converters inherently experience low-frequency power pulsations caused by the double-line-frequency ripple power arising from the instantaneous mismatch between the AC-side and DC-side power. Conventionally, this ripple is mitigated by incorporating bulky electrolytic capacitors in the DC-link. Although passive filtering effectively suppresses voltage fluctuations, it increases the converter size, reduces power density, and limits system reliability due to the relatively short lifetime and ageing characteristics of electrolytic capacitors. To address these limitations, active power decoupling (APD) techniques have gained significant attention as an effective alternative. APD diverts the low-frequency ripple power to auxiliary energy storage elements, thereby reducing the dependence on large DC-link capacitors and improving the overall performance, efficiency, and lifetime of the converter. However, most existing APD topologies require additional passive components, such as inductors or large film capacitors, together with auxiliary switching devices. These extra components increase circuit complexity, component count, installation space, and overall system cost, limiting their practical implementation in compact power electronic systems. The proposed approach employs a symmetrical half-bridge active power decoupling circuit that provides effective ripple power compensation with a reduced number of components. The topology utilizes only two low-value capacitors and two active switches to absorb and regulate the fluctuating power, eliminating the need for bulky energy storage elements. As a result, the proposed design offers a compact, cost-effective, and reliable solution with improved power density, enhanced efficiency, and extended converter lifetime, making it a promising choice for next-generation single-phase power conversion applications.

STATCOM-Based Reactive Power Compensation in Distribution Networks: A Review of Sizing, Control, and Renewable Integration Literature

Tejaskumar Ashokrao Rewatkar — 2026-09-19

Distribution feeders were not built to handle power flowing both ways. Rooftop solar has changed that. When solar panels send power back up the line, voltage can rise too high. Old capacitor banks cannot fix this fast enough because they only switch on and off in steps. This paper looks at a device called STATCOM, and its smaller version, D-STATCOM, which can push or pull reactive power almost instantly. It works much faster than old methods. This paper reviews research on four things. First, where to place STATCOM devices and how big they should be. Second, how their controllers are built. Third, how they work together with solar and wind power. Fourth, how they compare to an older device called SVC. Sizing methods have changed over time. Older studies used simple trial-and-error search. Newer studies use mathematical methods that guarantee a better answer. Controller design has also changed, moving from simple PI controllers to smarter fuzzy and AI-based controllers. But these three research areas barely talk to each other. Also, almost every study on sizing tests its method on a made-up IEEE test network, not a real power line. This paper also looks at real loss numbers from Indian power companies, both nationally and in Maharashtra state. This shows how big this research gap really is. At the end, the paper suggests ways to connect sizing, control, and real utility data better than before.

Journal of Electrical and Power System Engineering

Active Filtering-Based Decoupling of Fluctuating Power in Single-Phase Converters

STATCOM-Based Reactive Power Compensation in Distribution Networks: A Review of Sizing, Control, and Renewable Integration Literature