Nowadays, we use all kinds of wireless electronic devices including cell phones, wearable gadgets, laptops, tablets etc. With these devices we were moving away from needing to be continuously plugged into a power line.
At present, researchers and engineers are focusing on removing the last lingering wires altogether by building wireless power transfer technology.
Seven years ago the MIT (Massachusetts Institute of Technology) introduced of the Coupled Magnetic Resonance System (CMRS) using a magnetic field to transfer energy for a distance of 2.1 meters.
Now, Professor Chun T. Rim’s team at Nuclear & Quantum Engineering at KAIST, Korea, introduced distance-wireless transfer of electric power using their Dipole Coil Resonant System (DCRS).
The DCRS allows inductive power to be transferred at a 5 meter distance between transmitter and receiver coils.
The MIT system has several problems including low transfer efficiency and 2,000 Q factor that renders resonant coils sensitive to environmental changes such as temperature, humidity, and human proximity.
Instead, the DCRS has an optimally designed coil structure with two magnetic dipole coils. The primary coil induces a magnetic field and the secondary receives electric power.
Different than the CMRS with large and thick loop-shaped air coils, the KAIST system is build of solid ferrite core rods with windings at their centers generating a magnetic field. The linkage magnetic flux induces the voltage at the secondary winding.
The CMRS has a low Q factor of 100 and is 20 times less sensitive towards environment changes than the CMRS. In addition, the system works well at a low frequency of 100 kHz.
Recent research results show that the maximum output power of the DCRS is:
- 1,403 W at 3 meter distance with system power efficiency of 36.9% (100 W of electric power transfer)
- 471 W at 4 meter distance with system power efficiency of 18.7% and
- 209 W at 5 meter distance with system power efficiency of 9.2%
These data would translate into the DCRS being capable to power a large LED TV as well as three 40 W-fans can be powered from a 5 m distance.
The DCRS technology proves a novel remote, wireless, power delivery mechanism.
Even though this long-range wireless power transfer system is in early stage of commercialization and currently fairly expensive to implement, the Korean research team strongly believes that their system is laying the foundation for electric power supply of the future and that we all will soon charge our gadgets via wireless systems.
