Separation of the energy absorption and overvoltage protection in solid-state breakers by the use of parallel varistors
2014 (English)In: IEEE transactions on power electronics, ISSN 0885-8993, E-ISSN 1941-0107, Vol. 29, no 6, 2715-2722 p.Article in journal (Refereed) Published
Hybrid and solid-state breakers offer new possibilities in the power grid by enabling faster switching, and by simplifying dc breaking. However, they consists of expensive power electronic components that are sensitive to overvoltage transients and require energy absorbing elements mounted in parallel. At turn-off, the rapidly decreasing current in the power electronic switch and the presence of an inherent stray inductance leads to hazardous overvoltage transients across the breaker. This paper investigates the possibility to split the overvoltage protection and energy absorption into two separate components. By optimizing the voltage ratio between two varistors, one can dimension a small electronics varistor for overvoltage protection and a large power electronics varistor for energy absorption. With this setup the power electronics varistor is allowed to be in a circuit with a large stray inductance and can thus be placed further away without causing an uncontrolled overvoltage. It is shown both in circuit simulations as well as in a small-scale experiment that if the voltage ratio between the two varistors is large enough, the inner varistor only has to absorb 1-2% of the system energy.
Place, publisher, year, edition, pages
2014. Vol. 29, no 6, 2715-2722 p.
DC breaker, metal oxide varistor (MOV), overvoltage protection, snubber circuit, solid-state circuit breaker
Other Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-142295DOI: 10.1109/TPEL.2013.2272857ISI: 000331554000012ScopusID: 2-s2.0-84893916784OAI: oai:DiVA.org:kth-142295DiVA: diva2:703018
QC 201403052014-03-052014-02-282014-03-27Bibliographically approved