Multiparallel Inverter Control Strategy for Grid-Supporting P2G Systems

This article introduces a novel control approach to obtain higher grid reliability using power-to-gas (P2G) conversion systems. The proposed control method named multiparallel vector current control is a variant of virtual synchronous machine (VSM) applied to the multiparallel inverter system (MPIS). It takes on the good qualities of VSM control, such as offering inertia, voltage support, the ability to operate in standalone mode, and strong performance in weaker grids. Moreover, this concept boasts swift current set-point tracking abilities and enhanced synchronization properties. Integration of the P2G system involves an MPIS that transforms ac power from renewable sources into usable dc power, along with an electrolysis device. The later utilizes dc power source to generate hydrogen and oxygen by decomposing water. This integration strategically prevents grid-induced overvoltage or undervoltage from affecting the electrolysis device. This protects it from malfunctions or damage while keeping the voltage and frequency within the normal range. The efficacy of the proposed control method is rigorously substantiated through analytical models, time-domain simulations, and experimental validation in real-world applications. This comprehensive validation process underscores its viability and robustness in ensuring grid stability while facilitating efficient P2G conversion operations.