Researchers in Korea have overcome a 100-year old technological limitation by fabricating the world's first Mott device that reduces the size and enhances the performance of traditional electromagnetic switches and circuit breakers.
The research team, led by Dr. Hyun-Tak Kim of Korea’s Electronics and Telecommunications Research Institute, has developed an innovative power interruption technology based on a Mott metal-insulator transition (Mott MIT) device.
The Mott MIT signifies the phenomenon that a Mott insulator is abruptly converted into a metal or vice versa without the structural phase transition. The research team previously developed a Mott MIT critical temperature switch (CTS) (or MIT device) which generates a control current (or signal) at a critical temperature between 67oC and 85oC as the unique characteristic of vanadium dioxide. After that, the MIT devices were applied to some kinds of electromagnetic switches that interrupt an electric current in case of overcurrent.
An existing traditional electromagnetic switch that takes the role to interrupt electricity through the mechanical switching when it conducts an overcurrent is composed of both an electromagnet called the magnetic contactor, which connects or disconnects signals of main power, and the thermal overload relay with an on-off switching function controlled by temperature.
The overload relay is composed of both an expensive delicate mechanical switch with a large size and a bimetal that is made of two separate metals with different thermal expansion coefficients joined together. The bimetal has a characteristic of bending to any direction when heat is applied.
The bending force of the bimetal controls the mechanical switch inducing the on-off switching; this has been called ‘hundred years technology of power interruption’; Westinghouse applied the patent right of the power circuit breaker using a bimetal in 1924. However, the bimetal undergoes a change of the bending characteristic during a long-term usage. Therefore, the accuracy of the overload relay drops.
Finally, the performance of electromagnetic switch is also deteriorated; this is a fatal problem of the existing traditional electromagnetic switch.
In order to solve the problem, the research team uses the MIT-CTS instead of the bimetal as a sensor for the on-off switch. In this case, the mechanical switch is replaced by a simple electrical circuit controlling the electromagnet, which means that the mechanical switching is changed into the electronic one. Therefore, the MIT overload relay becomes small in size by removing the large mechanical switch and has the accuracy irrespective of environment temperature during long term. Accordingly, the MIT electromagnetic switch has a reliable and accurate electronic switching characteristic.
The research team confirmed that the developed MIT electromagnetic switch is satisfied with the operating conditions of the overload relay given in a Korean technology standard, Article 5.6, KSC 4504 compatible with the international standard 60947-4-1. The team also checked through experiments that the circuit breaker using the bimetal operated below AC 1 KV can be replaced by that made of the developed MIT electromagnetic switching technology.
A market report on “The World Market For Transmission & Distribution Equipment and Systems” (Gould Report, 2013) announced that the sales of the worldwide power switch and circuit breaker markets will reach to approximate $29.5 billion in 2016.
For more information, please contact
Dr. Hyun-Tak Kim
E-mail : email@example.com
Tel: +82 42 860 5731)
Established in 1976, ETRI is a non-profit Korean government-funded research organization that has been at the forefront of technological excellence for about 40 years. In the 1980s, ETRI developed TDX(Time Division Exchange) and 4M DRAM. In the 1990s, ETRI commercialized CDMA(Code Division Multiple Access) for the first time in the world. In the 2000s, ETRI developed Terrestrial DMB, WiBro, and 4G LTE Advanced, which became the foundation of mobile communications. Recently, as a global ICT leader, ETRI has been advancing communication and convergence by developing SAN(Ship Area Network) technology, Genie Talk(world class portable automatic interpretation; Korean-English/Japanese/Chinese), and automated valet parking technology. As of 2015, ETRI has about 2,000 employees where about 1,800 of them are researchers.
* Homepage : https://www.etri.re.kr/eng/main/main.etri
Noh Hoon PARK | Research SEA
The world's most powerful acoustic tractor beam could pave the way for levitating humans
22.01.2018 | University of Bristol
Siberian scientists learned how to reduce harmful emissions from HPPs
22.01.2018 | Siberian Federal University
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
22.01.2018 | Materials Sciences
22.01.2018 | Earth Sciences
22.01.2018 | Life Sciences