Wireless power supply innovation opened by high-frequency power electronics
The advent of smartphones has revolutionized our entire society. This revolution was triggered by “wireless” communication, which allowed us to connect to the Internet anytime and anywhere. The impact of wireless in our daily lives has been quite significant. Looking around, one can notice that many electronic devices, such as watches, speakers, or lights, around us are becoming wireless. The next to become wireless will be the power cords in the room. If we can easily obtain electric power "anytime and anywhere" without any difficulty, it may have the same social impact as the advent of smartphones.
We are conducting research and development on "wireless power transfer," in which electric power is transmitted wirelessly. As shown in Figure 1, there are several methods for wireless power transfer, and we are focusing on "electromagnetic coupling" and "magnetic resonance coupling" that use coils. For transmitting power wirelessly, it is necessary to create an alternating current (sinusoidal wave). Our primary research aim is to increase the frequency (number of waves per second) of this alternating current. By increasing the frequency, the power-transmission distance can be extended and more efficient power transfer can be achieved.
We have been working on this research from an information science viewpoint and have developed our original design software. We are also developing technology to enable a stable power supply even when the state of the charging side (position and charging status) varies. By using these proprietary technologies, we hope to establish a wireless-power-transfer technology that is easy and convenient for everyone to use. We plan to develop a wireless-power-transfer system using drones in our most recent development project, as shown in Figure 2.
The concept of wireless power transfer can be traced back more than 120 years, and its prototype can be found in the "Earth System" by Nicola Tesla, who is said to be Edison's rival. We are gradually moving towards materializing the technology that the past researchers have dreamed of for many years by making full use of the latest technology. The exciting aspect of this research is that we can advance our study and realize our long-held dream.