NICHICON, Osaka University and RIKEN collaborated on a NEDO project*2using next-generation semiconductor SiC. This technology is expected to enable energy conservation through equipment miniaturization and other advances.This collaboration resulted in the development of power conversion modules capable of stable, high-frequency driving power. This was successfully verified as an accelerator power supply for the large synchrotron radiation facility“SPring-8” X-ray Free Electron Laser (SACLA*4), this system requires high precision and stability.
NICHICON will promote the application of this technology going forward, from advanced medical accelerator power supplies and electric cars, to Vehicle to Home (V2H) systems supplying electric power to ordinary households and public/industrial power storage systems. In addition, Osaka University will lead efforts to encourage and promulgate the practical application of power conversion modules using next-generation semiconductor SiC by incorporating this into the establishment of reliability evaluation methods and other guidelines and standardization activities in Japan and overseas.
Power conversion module using next-generation semiconductor SiC
(size: 86×84×24.8 mm [left]),
power source product for installation (V2H system [center])
and a public/industrial power storage system [right]
In the past several years, there has been a growing demand for energy-saving electronic devices. Other than existing Si semiconductors, the practical application of next-generation semiconductor SiC is expected to enable low loss and high-speed switching with minimal power consumption. In addition, it can drive higher frequencies than existing semiconductor modules, making it possible to miniaturize components such as inductors, enabling smaller power source products. At the same time the various energy-saving effects are expected to include the elimination of components used as well as energy reduction during product transportation. However, the practical application of high frequency drivers also present challenges, such as increased noise and subsequent impact on stability.
NICHICON CORPORATION, Osaka University and RIKEN collaborated on this NEDO project using next-generation semiconductor SiC to develop a power conversion module capable of stable and high-frequency driving power. The miniaturization of power source equipment allows for up to two-thirds the size of conventional equipment. After the installation of a particle accelerator equipment power source for the large synchrotron radiation facility “SPring-8” X-ray free electron laser (XFEL*3) facility (SACLA), which requires high precision and stability, we were able to confirm that there was no impact from noise resulting from the high-frequency driving power of the power conversion module. In addtion we were able to successfully verify that it operated comparably to existing Si semiconductor modules. Going forward, NICHICON will promote the application of this technology in products ranging from advanced medical accelerator power supplies*5 and electric cars, to Vehicle to Home (V2H) systems supplying electric power to ordinary households and public/industrial power storage systems.
Furthermore, as SiC semiconductor modules that operate in high heat environments cannot be evaluated using the same methods and standards as existing Si semiconductor modules, the NEDO project is engaged in the establishment of reliability evaluation methods and other guidelines and standardization activities in Japan and overseas. These activities mainly include the establishment of the WBG Consortium*6with the participation of major device and machinery manufacturers led by Osaka University, and a cooperative system involving Japanese standardization institutions including the Japan Electronics Packaging and Circuits Association, the Japan Electronics and Information Technology Industries Association and the Japan Fine Ceramics Association.
Incorporating the results of this verification into guidelines and standardization activities will accelerate the practical application and spread of SiC semiconductor modules.
These results will be exhibited in the NICHICON CORPORATION booth during Smart Energy Week 2017 at the Eighth International Rechargeable Battery Expo held at Tokyo Big Sight from Wednesday, March 1, to Friday, March 3, 2017. (Official website: http://www.batteryjapan.jp/en/Home/)
In this project, the gate drive circuit*7 was stored in the module and the SiC power MOS-FET*8 was used to increase the number of drive frequencies to a higher frequency, resulting in the development of a power conversion module that can be applied in V2H systems with power conversion capacities ranging in class from several kW to several dozens of kW, public/industrial power storage systems and advanced medical accelerator equipment power supplies. In addition, miniaturizing capacitors, transformers and other components adjacent to the circuit enabled reduction to two-thirds the size of conventional equipment.
Osaka University and NICHICON collaborated to examine the inductance reduction and optimization*9 of overall circuit due to concerns about increased noise caused by the power transformer module’s high-frequency driving power. The power conversion module we developed were installed in the accelerator deflecting electromagnetic power source*10and the magnetic field stability*11of the deflecting electromagnet was measured. Furthermore, the power source was used to excite the deflecting electromagnet in the X-ray free electron laser (XFEL)beam transfer line to verify the effects on laser output*12. As a result, the collaboration with RIKEN successfully confirmed and verified that performance was comparable to existing Si semiconductor modules and that there was no impact from noise*13 caused by the high-frequency driving power from changes in the laser transmission and profile (laser beam shape: see figures below).
SACLA [up] and laser profile images [down]
Silicon carbide. A combination of silicon and carbon, compared to conventional silicon semiconductor devices, semiconductor devices made with this compound have internal power loss as little as 1/100 and can be used at high frequencies and high temperatures (up to about 300°C).
*2. NEDO project
Clean Device Social Implementation Promotion Project/Ultra-Small Power Conversion Module Multipurpose Social Implementation Using Next-Generation Semiconductors (fiscal 2015–2016)
XFEL is an acronym that stands for X-ray free electron laser. This X-ray region pulse laser was realized through advances in accelerator technologies in recent years. Unlike conventional lasers using semiconductors or gas as an oscillation medium, in principle, there is no fundamental wavelength limitation since an electron beam moving at high speed in a vacuum is used as the medium.
Japan’s first XFEL facility jointly constructed by RIKEN and the Japan Synchrotron Radiation Research Institute.One of the five core national technologies under the Science and Technology Basic Plan, the facility was constructed and developed in accordance with a five-year plan launched in fiscal 2006. The facility was completed in March 2011 and given the name SACLA, which stands for SPring-8 Angstrom Compact free electron Laser. The first X-ray laser oscillation was in June 2011, the use of which has been shared since March 2012. This X-ray laser has the ability to oscillate at the world’s shortest wavelength, below 0.1 nanometers.
For details, please visit: http://xfel.riken.jp/eng/index.html
*5. Advanced medical accelerator device power source
Power source used to accelerate protons and baryons for particle beam therapy to treat cancer cells with radiation. The acceleration of protons and baryons requires a power source with high precision and stability.
*6. WBG Consortium
Originally promoted and established in 2013 by Osaka University professor Katsuaki Suganuma with the intention of establishing an evaluation methodology, this next-generation semiconductor (SiC and GaN) mounting technology holds the key to an energy-saving technology known as wide band gap (WBG) semiconductors. 37 major affiliated companies including device and equipment manufacturers have participated in the promotion of initiatives toward SiC modulereliability and standardization.
*7. Gate drive circuit
A circuit that converts a control signal from a microcomputer or other device into a gate driving voltage/current signal for turning on/off a power MOS-FET.
*8. Power MOS-FET
High-power metal-oxide semiconductor (MOS) field effect transistor (FET).
*9. Inductance reduction and optimization
To avoid increased loss and lower responsiveness of the SiC power MOS-FET in the circuit, the inductance of the entire circuit is reduced as much as possible by devising wiring patterns in the circuit, etc.
*10. Accelerator deflecting electromagnetic power supply
A power supply for driving an electromagnet to change the trajectory of an electron beam.
*11.Deflecting electromagnet magnetic field stability
For the 24-hour magnetic field stability standard value of 200 ppm, the SiC module power supply was 50 ppm (note that this includes the magnetic field variation caused by electromagnet yoke temperature changes).
*12. Effects on laser output
XFEL pulse energy did not change at 85 µJ for both the Si semiconductor power source and the SiC power source. No difference was seen in the stability of the laser pulse and electron beam trajectory between the two power supplies.
*13. Impact of noise from the high-frequency driving power
There was no impact on the accelerator control, monitoring equipment and other components surrounding the power source (there is also no impact even when offline).
(Inquiries regarding details in this news release)
NICHICON CORPORATION: NECST Business Headquarters
Contact: Mr. Furuya; TEL: +81 75-241-2564
NEDO: IoT Promotion Department
Contacts: Mr. Hattori/Mr. Kurihara; TEL: +81 44-520-5211
Osaka University: Institute of Scientific and Industrial Research
Contact: Professor Suganuma; TEL: +81 6-6879-8521
Osaka University: School of Engineering
Contact: Professor Funaki; TEL: +81 6-6879-7709
RIKEN: Spring-8 Center
Contact: Mr. Hara; TEL: +8 791-58-2800
(General inquiries regarding other NEDO projects)
NEDO: Public Relations Department
Contact: Mr. Fujimoto/Mr. Takatsusa/Mr. Sakamoto; TEL: +81 44-520-5151