Fuji Electric Review
Vol.71-No.1,2025
Energy Systems That Contribute to the Stable Supply, Optimization, and Stabilization of Energy
Energy Systems That Contribute to the Stable Supply, Optimization, and Stabilization of Energy
In the field of energy systems, various efforts are being made toward the realization of a carbon-free society, such as expanding the use of renewable energy, stabilizing the energy supply and saving energy.
This special issue introduces plants, systems and component products (equipment) offered by Fuji Electric to contribute to the stable supply, optimization and stabilization of energy, as well as the technologies that support them.
ISHIGAME, Atsushi
KAWANO, Masashi; TOYAMA, Kentaro; HIROSE, Jun
Fuji Electric offers products and solutions that can achieve stable, optimal, and reliable supply of energy in the fields of power generation, energy management, power supply and facility systems, and substation equipment.
In the power generation field, we are promoting the advancement of GTCC, the introduction of geothermal, hydro and biomass power, fuel conversion, the increase of ORC/flash efficiency, and the demonstration of fuel cells, as well as the improvement of safety and the response to the market expansion for nuclear power. In the energy management field, asynchronous power sources have been expanding as the ratio of renewable energy has been increasing. We are thus promoting the development of a storage battery transaction operation system, equipment monitoring, OpenADR support, GFM inverters, and an emulated inertia control function-equipped PCS for battery energy storage systems, contributing the power grid stabilization. In the power supply and facility systems field, we are promoting the shortening of construction periods and standardization of electrical equipment for internet data centers through the adoption of skid systems. We are also engaged in extending the life of uninterruptible power supplies and strengthening IoT monitoring systems. In the substation equipment field, we are working to stabilize the power grid by introducing static var compensators for electric furnaces, relax fire prevention requirements by increasing the use of vegetable-oil transformers, and improve product reliability by establishing our own short-circuit test equipment.
HATTORI, Yasuyuki; YAMASAKI, Takenobu
While the 7th Strategic Energy Plan calls for an increase in the ratio of renewable energy sources such as geothermal power generation, thermal power generation is still expected to make up roughly 30% to 40% of the energy supply. Fuji Electric is working to reduce greenhouse gas emissions in both the geothermal and thermal power generation sectors. In the field of geothermal power generation, we have developed a technology to apply diamond-like carbon coating to turbine blades, preventing silica scale adhesion. This reduces cleaning frequency and allows the turbine blades to maintain high power generation output. In addition, in the thermal power sector, we have developed a technology that improves the co-firing rate of carbon-free fuels such as hydrogen, ammonia, and biomass, and enables exclusive firing of these fuels through turbine modifications.
OKAMOTO, Ryoichi
As part of efforts to realize a carbon-free society, hydrogen fuel cells that use hydrogen as fuel to generate electricity and heat without emitting CO2 are expected to serve as a key technology for the effective use of hydrogen. Fuji Electric has developed a stationary hydrogen fuel cell system with a rated output of 180 kW, which can easily be expanded to 360 kW. For the fuel cell module, we adopted an in-vehicle polymer electrolyte fuel cell with a short startup time, along with our proprietary operation control technology, achieving extended continuous operation and high durability. The system is equipped with an isolated operation function that can respond to rapid load changes and serve as a private power generator for emergency use.
OKA, Naoya; UEMURA, Hirofumi; YAMADA, Makoto
In recent years, the adoption of renewable energy has been expanding as part of efforts to realize a carbon-free society. As the number of synchronous generators capable of maintaining grid frequency declines, frequency fluctuations may increase in the event of grid failures or sudden imbalances between supply and demand. To address this problem, Fuji Electric is developing an emulated inertia control function-equipped PCS for battery energy storage systems, which emulates two frequency maintenance capabilities: inertial response, which serves as a frequency maintenance mechanism as same as synchronous generators, and frequency response as primary reserve (governor control), which respond within a few seconds to support frequency. We used a miniature model to verify that developed function allows a PCS for battery energy storage systems to instantaneously supply power as inertial response to load fluctuations to suppress frequency fluctuations, thereby maintaining the stability of the grid.
OMIYA, Kazuki; SHINOHARA, Hiroshi; OKAZAKI, Yohei
In recent years, in line with the global trend toward a decarbonized society, the blast furnace steel industry has been shifting toward electric furnaces that can reduce CO2 emissions. In electric furnaces, short circuits and other faults can cause sudden changes in arc resistance, resulting in voltage drops on the grid, as well as periodic voltage fluctuations (flicker failure). Therefore, equipment that compensates for reactive power fluctuations is indispensable. Fuji Electric has been manufacturing and selling static var compensators since the early 1970s. At present, we offer the following three types: a separately-excited type that uses thyristors as devices to handle large currents, making it suitable for increasing capacity; a self-excited type that uses devices such as IGBTs to achieve high compensation performance; and a hybrid type that combines the separately-excited and self-excited types.
NISHIDATE, Jun; KANEKO, Akinobu; TOKUDA, Tsuyoshi
To meet the demand for further energy saving, high reliability, and labor-saving in factories and broadcasting and communication equipment, Fuji Electric is marketing and supplying the “FX Series” of medium-capacity uninterruptible power supply systems (UPSs), which incorporate the specifications of previous models while delivering enhanced functionality. To shorten customer system design time, we offer the “F.U PAQ” standard package, which combines the UPS main unit and peripheral panels. And to reduce equipment downtime due to maintenance, major replacement parts are modularized. In addition to supporting a rated load power factor of 0.9 and expanding the voltage range of the connected battery, we are developing products that apply lithium-ion batteries, which enable smaller and lighter systems with longer life, as well as options with enhanced earthquake resistance.
NOGUCHI, Masakazu; MATSUNAGA, Kei; TAKAHASHI, Jun
The markets for cast resin transformers are growing in line with capital investment in data centers, which is booming not only in Japan but also in ASEAN countries. Since transformers used overseas have primary voltages as high as 22kV or 33kV, they need to be installed within protective enclosures to ensure safety. Fuji Electric has therefore developed the MOLTRA that features an innovative insulating structure to reduce the installation area by 17% and weight by 13% compared to an existing model. In addition, we are working to develop solutions to challenges in data center applications, such as handling load currents with significant harmonic content and applying skid systems that can shorten installation periods.
CHIBA, Koichiro
Mineral oil, which has been used as insulating oil for oil immersed transformers, poses problems such as CO2 emissions during disposal and environmental pollution due to unexpected oil leaks. To address these problems, ester-based insulating oil has been developed and is increasingly being applied to oil immersed transformers. This oil is derived from plants and features excellent biodegradability. In FY2008, Fuji Electric launched a transformer that uses palm fatty acid ester produced by esterifying palm oil. In addition, we added a transformer that uses esterbased insulating oil made from soybean oil to the product lineup in FY2022. Going forward, we will continue to provide environmentally friendly products that satisfy our customers.
FUJISHIRO, Satoshi; MIZUMOTO, Takayuki; ABE, Naoki
Improving testing efficiency has been a challenge in efforts to meet the steadily growing demand for high-voltage substation equipment products with minimal environmental impact that satisfy Japanese and overseas standards. To address this, we constructed short-circuit test equipment using a short-circuit generator at Fuji Electric’s Chiba Factory and established a system to verify the performance of substation equipment in-house. The newly installed shortcircuit generator enables testing at 50 and 60Hz using the latest shaft system design technology. Using an inverter to drive the motor for the power source allows the equipment to use regenerative braking by the inverter for shortening the shutdown time and effectively utilizing regenerative power. This equipment will shorten development periods compared to past approaches, contributing to the timely launch of new products.
