Harmonic Cancellation in Multi-Electrolyzer P2H Plants via Phasor-Modulated Production Scheduling

TL;DR

This paper introduces a novel coordinated scheduling method for multiple electrolyzers in P2H plants that reduces harmonic distortion, ensures grid compliance, and improves economic performance with minimal hydrogen output loss.

Contribution

It develops a harmonic model for TR-powered electrolyzers and proposes a phasor modulation-based operation scheme for harmonic mitigation in large P2H plants.

Findings

Harmonic currents reduced by up to 39.7%.

Grid-code compliance achieved with minimal hydrogen output loss.

Total revenue increased by over 21%.

Abstract

Thyristor rectifiers (TRs) are cost-effective power supplies for hydrogen electrolyzers (ELZs) but introduce harmonic distortion that may violate grid codes. This letter proposes a self-governing harmonic mitigation strategy through coordinated operation of multiple ELZs in large power-to-hydrogen (P2H) plants. First, the harmonic model of TR-powered ELZs is derived, revealing a natural harmonic cancellation mechanism among them. Based on this, a system-level operation scheme based on phasor modulation is developed and integrated into plant scheduling. Case studies demonstrate that the proposed method reduces harmonic currents by 21.2%-39.7% and ensures grid-code compliance, with only a 0.25% loss in hydrogen output, while increasing total revenue by over 21\% compared to production-oriented strategies.