On switching transient modeling and analysis of electronic on-load tap-changers based Sen transformer. (September 2021)

• Record Type: Journal Article
• Authors: Pan, Yuhang; Han, Song; Zhou, Chao; Guo, Xi
• Is Part Of: International journal of electrical power & energy systems. Volume 130(2021)
• Publication Date: 2021-09
• Subjects: Electronic on-load tap-changer (EOLTC) -- Electronic on-load tap-changer based Sen transformer (EST) -- Switching transient modeling -- Commutation process -- Voltage spike; Electrical engineering -- Periodicals; Electric power systems -- Periodicals; Électrotechnique -- Périodiques; Réseaux électriques (Énergie) -- Périodiques; Electric power systems; Electrical engineering; Periodicals; 621.3
• DOI: 10.1016/j.ijepes.2021.107024
• Languages: English
• ISSNs: 0142-0615

Abstract

Highlights: A topology of electronic on-load tap-changer based Sen transformer (EST) is proposed, especially for distribution system. There is an analytical study on switching transient model of the EST. Some numerical analyses have been done for studying the commutation process and voltage regulation in the EST. Abstract: This paper presents the switching transient model and analysis for an electronic on-load tap-changers (EOLTC) applied to a Sen transformer (ST), including the steady-state voltage and current of the electronic switches, the evaluation of current and voltage transients during the commutation process, and the dimensioning of the EOLTC and voltage spike protection. Firstly, according to the topology of the EOLTC, the steady-state voltage and current models of the EOLTC are established. Secondly, the switching transient model of the EOLTC in overlapping time is derived based on the T-equivalent circuit and Kirchhoff's voltage law. Finally, the overlap time and voltage spike of the EOLTC are evaluated through the switching transient model, and the voltage spike protection is designed. With the help of MATLAB and PSCAD/EMTDC, two case studies have been carried out on a small-capacity and large-capacity electronic on-load tap-changers based Sen transformer (EST). The influence of different power factors on the overlap time is analyzed. The results show that the load power factor may affect determining the overlap time of the commutation process of the EOLTC. The more the inductive load, the faster the overlap current on the tap-changer rises during the overlap period. Furthermore, it is also verified through the time-domain simulation that the application of high-power EOLTC in the ST can increase the speed of operation of the conventional ST.