IEEE Xplore has recently published our new research dedicated to the development of an advanced active damping strategy for grid-tied inverters equipped with LC/LCL filters. The work addresses one of the most relevant challenges in modern power conversion systems: ensuring stability and power quality while minimizing hardware complexity and filter losses.
Why this topic is crucial
In grid-connected inverters, LC and LCL filters are used to limit the injection of switching harmonics. To reduce filter losses, damping resistors are often minimized, but this can lead to poorly damped or even unstable operating conditions near the resonance frequency.
The scientific literature has proposed several active damping solutions; however, many require additional current sensors or complex algorithms and provide limited guidance on tuning criteria.
Our contribution
The paper presents a sensorless active damping methodology, based on a resonant current estimator and characterized by:
no additional sensors,
a streamlined and robust control algorithm,
direct and immediate parameter tuning,
strong experimental validation.
The solution was tested on a 30-kVA, three-phase, two-level inverter, confirming its robustness and repeatability in realistic operating scenarios.
This result highlights the importance of our collaboration with the Politecnico, which continues to offer opportunities to develop innovative, internationally oriented projects capable of producing contributions recognized by the scientific and technical community.
Industrial applications enabled by the technology
The proposed active damping strategy is not just an academic advancement but a solution with direct impact on several high-tech industrial applications:
Energy Storage Systems (ESS) and microgirds
Improved stability even under grid variations; reduced sensing requirements; shorter integration times.
Utility-scale photovoltaic inverters
Superior performance on weak grids; increased efficiency; lower control hardware complexity.
Fast-charging systems and bidirectional architectures (V2G)
More compact filters, better power quality, higher efficiency in highly dynamic applications.
High-power industrial converters
Enhanced dynamic robustness, reduced resonance oscillations, improved overall system reliability.
The work represents a step forward in the development of advanced control techniques for grid-tied inverters, with immediate benefits both technologically and in terms of practical applications. The integration of sensorless methodologies, combined with simplified tuning criteria, paves the way for more efficient, scalable, and industrially sustainable solutions.
The full paper is available here.
