The first domestic set! The experimental equipment for connecting a 20 kV medium voltage DC microgrid to an electrolytic aluminum DC system has been successfully tested

On August 15th, the performance testing and debugging of the first domestic 20 kV medium voltage boost and buck 7.8 MW DC technology developed by Huanghe Xinye Company was successfully integrated into the electrolytic aluminum DC system experimental equipment, marking a solid step for Huanghe Company in the deep integration of new energy photovoltaic DC systems and electrolytic aluminum DC systems.

As the first high-power water-cooled medium voltage DC photovoltaic system connected to electrolytic aluminum DC system in China, its research and development, integration, testing and experimentation process has explored a new route for large-scale new energy generation and on-site consumption, laying an important technical foundation for the State Power Investment Corporation and similar projects in the industry. It is of great significance for promoting the deep integration of green energy and green manufacturing in the electrolytic aluminum industry in the future.

Compared to electrolytic aluminum enterprises in the industry that use photovoltaic power generation, they need to go through three levels of conversion: DC/AC, step-up and step-down isolation transformers, and AC/DC, which involves multiple links and significant energy loss. Huanghe Xinye Company has carried out research and application of 2.4 MW single machine and 7.8 MW single machine DC/DC technology based on practical work. For the first time, it innovatively proposed the implementation of a 20 kV medium voltage DC/DC microgrid connection scheme. On the basis of the first phase of 2.4 MW photovoltaic DC power connection to the electrolytic aluminum DC system, the company has completed the design, development, system integration, and performance testing of the first set of experimental equipment for connecting a 20 kV medium voltage DC microgrid to the electrolytic aluminum DC system in China.

After the project was approved, a joint project team was established by the Production Technology Department, Science and Technology Committee, Power Plant, and Aluminum Product Innovation Center of Huanghe Xinye Company. Multiple design seminars were held to discuss the introduction of medium voltage boosting and lowering microgrids, and the acceptance ability of electrolytic aluminum DC systems for high-power and long-distance photovoltaic DC systems. In depth discussions were conducted on various technical requirements, technical routes, safety requirements, performance indicators, etc., and a modular water-cooled DC high-voltage isolation scheme was determined to be adopted. Detailed deployment was made for the research and development process.

The experimental equipment will begin trial production in December 2023 and gradually carry out bench tests. During the development process, two full load tests were conducted. The first experiment solved the industry technical problems of high-power high-frequency drive technology and compact distributed water-cooled high-voltage isolation technology, and the second experiment solved the technical problems of comprehensive control of high-voltage DC microgrids. Finally, on August 15th, all performance indicators of the experimental equipment were achieved.