Coordinated Active-Reactive Power Management of ReP2H Systems with Multiple Electrolyzers

TL;DR

This paper presents a coordinated power management strategy for ReP2H systems with multiple electrolyzers, optimizing active and reactive power to improve efficiency and reduce losses.

Contribution

It introduces a novel mixed-integer second-order cone programming approach for joint scheduling of active and reactive power in ReP2H systems, enhancing performance.

Findings

Reduced system losses by 3.06%

Increased hydrogen production by 5.27%

Effective coordination improves safety and economy

Abstract

Utility-scale renewable power-to-hydrogen (ReP2H) production typically uses thyristor rectifiers (TRs) to supply power to multiple electrolyzers (ELZs). They exhibit a nonlinear and non-decouplable relation between active and reactive power. The on-off scheduling and load allocation of multiple ELZs simultaneously impact energy conversion efficiency and AC-side active and reactive power flow. Improper scheduling may result in excessive reactive power demand, causing voltage violations and increased network losses, compromising safety and economy. To address these challenges, this paper first explores trade-offs between the efficiency and the reactive load of the electrolyzers. Subsequently, we propose a coordinated approach for scheduling the active and reactive power in the ReP2H system. A mixed-integer second-order cone programming (MISOCP) is established to jointly optimize active and reactive power by coordinating the ELZs, renewable energy sources, energy storage (ES), and var compensations. Case studies demonstrate that the proposed method reduces losses by 3.06% in an off-grid ReP2H system while increasing hydrogen production by 5.27% in average.