Medium voltage electric springs and harmonic detection: pioneering stability in power electronics dominated grid

Abstract

Climate change has driven the widespread adoption of large-scale renewable energy sources (RES) to reduce greenhouse gas emissions. However, integrating RES into the power grid leads to a reduction in synchronous generator usage and overall system inertia, affecting power system stability. This study explores power electronics-based electric spring (ES) technology as a solution to address these challenges. Traditional research has studied the use of ES at the mains-voltage level. New research in this study focuses on integrating the ES technology with the medium-voltage distribution network and large smart loads, investigating bidirectional ac-dc power converter systems like the neutral-point-clamped converter and the cascaded H-bridge converter with integrated dual-active-bridge topologies. Large smart loads, including wireless charging infrastructure, heating devices, and second-life batteries, leverage the ES for fast demand-side management and grid stability enhancement, facilitating increased renewable energy penetration. Additionally, the study proposes robust fundamental and frequency detection methods, validated through comprehensive simulations and scale-down experiments, to enhance the ES's performance. The research outcomes demonstrate the potential of medium-voltage ES in stabilizing the power grid and effectively integrating RES. This approach has the application potential of playing a vital role in reducing carbon emissions from the power system, contributing to global climate change efforts and paving the way for a more sustainable energy future.