Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Paradigm Shift to Mott device-based Power Interruption

02.11.2015

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.


Left figure shows the temperature dependence of resistance of the developed Mott MIT VO2 device and its photo. Right side exhibits the commercial overload relay and magnetic contact (electromagnet) and the developed electromagnetic switch.

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
ETRI
Dr. Hyun-Tak Kim
E-mail : htkim@etri.re.kr
Tel: +82 42 860 5731)


About ETRI
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


Associated links
Video and image on ETRI ewebzine
ETRI Homepage

Noh Hoon PARK | Research SEA

More articles from Power and Electrical Engineering:

nachricht Microhotplates for a smart gas sensor
22.02.2017 | Toyohashi University of Technology

nachricht Positrons as a new tool for lithium ion battery research: Holes in the electrode
22.02.2017 | Technische Universität München

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>