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 Waste from paper and pulp industry supplies raw material for development of new redox flow batteries
12.10.2017 | Johannes Gutenberg-Universität Mainz

nachricht Low-cost battery from waste graphite
11.10.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

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: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>