Validation & optimization of a method to design rectifier transformer for green hydrogen production

Abstract

The significant advancements in energy transition, particularly in the integration of renewable energy sources, have compelled energy engineers to devise sustainable stor-age solutions for the long term. Green hydrogen has emerged as the leading contender in this competition. Nevertheless, electrolyzers require substantial quantities of DC currents. The incorporation of a high-performance power-electronic embedded power system for the electrolyzers is an essential and unavoidable aspect of the design pro-cess. The design of a rectifier-transformer necessitates numerous unique considera-tions in contrast to a conventional grid transformer. The primary objective of this the-sis is to validate and optimize the methodology employed by Siemens Energy for the design of Rectifier-Transformers, with an exclusive emphasis on the electrical aspects. The validation process is conducted on an excel tool that has been designed within the organization. A custom MATLAB tool has been developed in parallel with advanced inputs and optimizations from the preliminary design method. The literature research encompasses an examination of the key electrical components that are integral to the power system, namely the Rectifier-Transformer, OLTC, PFC, and Grid Connections. Following this, the preliminary stages of the design encompass the assessment of the total and various individual electrical losses, which contributed to the overall dimen-sioning of the transformer. Subsequently, OLTC and the PFC are engineered to com-prehend the reactive powers and power factors inherent in the power system. The de-sign optimization involved the modification of specific characteristics, such as the di-mensions of the busbars or the limitations to the short circuit power. A transformer design tool has been developed, enabling the initiation of business activities with man-ufacturers. The transformer that has been designed within the tool is purported to possess a high level of accuracy in meeting real-time requirements.