Innovating with core technologies for hydrogen production! Four talented people taking on emerging markets

Hydrogen can be combined with oxygen to generate electricity or combusted for use as energy. Since it does not emit CO2 in the process, it is attracting attention worldwide as a clean energy source.

Ms. Ogawa, who is in charge of overseas sales, expressed her expectations saying, “Hydrogen is a new market, and there are still some unknowns as it is not yet a mature business sector, but an increasing number of new manufacturers are entering the market to take advantage of the trend toward decarbonization.”

Mr. Tamai, who has been with the company for 20 years, has been involved in the research and development of substation equipment and industrial power supply equipment at the Chiba Factory. In the development of a rectifier for hydrogen production, Mr. Tamai has been in charge of the control system for supplying an appropriate amount of current and voltage to the electrolytic cell that performs electrolysis.

In conventional rectifiers, diodes and thyristors have been used as semiconductor devices for power conversion, but the newly developed hydrogen production system uses IGBTs (see Note 1).

Mr. Tamai commented, “IGBTs can be switched on and off to reduce current distortion and maintain a constant voltage in power grids, making them effective when using renewable energy sources with unstable output, such as solar and wind power. In order to increase the amount of ‘green hydrogen’ produced from renewable energy, we decided that IGBTs should also be used in rectifiers. However, it is necessary to reconfigure the circuitry when applying IGBTs. Of course, this raised the technical hurdles, such as the need to devise a control system from scratch.”

Because there were concerns that the size of equipment and costs would increase if new circuits were configured using existing IGBTs, Mr. Tamai worked with the Matsumoto Factory, which develops and manufactures semiconductor devices, to develop a dedicated IGBT. Fuji Electric used its comprehensive strengths to meet the challenge.

Mr. Yamanodera, who is in charge of design, will commercialize the product based on the control system developed by Mr. Tamai.

Because rectifiers for aluminum smelting are large products that are made-to-order and have different specifications depending on the customer, the delivery time from order to shipment is normally about one year. However, to facilitate applications in hydrogen production, we needed to create a design that would allow for mass production.

Mr. Yamanodera remarked, “In order to mass-produce the rectifier, we decided on the structure and parts from the initial design stage, while keeping in mind the assembly procedure and workability. In addition, when we built the prototype, we personally observed the assembly work by the manufacturing department and repeatedly made improvements by reflecting the requests and technical advice of workers into the design, as well as the insights we gained from first-hand observation of the assembly work.”

Furthermore, in contrast to aluminum smelting, which uses large amounts of electricity, hydrogen production requires more compact products while providing sufficient space for maintenance. Mr. Yamanodera continued by saying, “We were able to save space and secure the space required for maintenance by utilizing the water-cooling technology developed for rectifiers and designing a system that efficiently cools the heat generated during equipment operation.”

Finally, Mr. Yoshida is in charge of verifying the system in which the product is used. In hydrogen production plants, many components such as rectifiers and electrolyzers work together, and interference between these components can affect the power grid and cause problems such as voltage flicker (see Note 2).

Mr. Yoshida said, “Engineering firms and end users evaluate the entire system, not just Fuji Electric’s products. To ensure that the product works properly no matter what equipment is connected to it, we verify and check everything one by one to eliminate any defects. Fuji Electric also develops equipment to compensate for unstable power, and our strength is that we can offer a wide range of systems to our customers.”

Based on Mr. Yoshida’s verification data, Mr. Tamai recreates the control program, and Mr. Yamanodera carries out the design.―― Just like a in relay race, after making several laps around the track, the baton is finally handed off to the anchor, Ms. Ogawa, who delivers the product to the customer.

Ms. Ogawa commented, “The hydrogen market is just getting started. Since customers were proceeding on their own, they have had varying voltage and current requirements for rectifiers. This made it difficult to identify common ground in specifications.”

To address this challenge, we developed a standard product with a capacity of 6 MW and an output current of 8000 A, which can be connected in series or parallel to accommodate the scale required by customers.