Step-Up Asymmetrical Nine Phase Delta-Connected Transformer for HVDC Transmission

Arafet Ben Ammar; Faouzi Ben Ammar

Step-Up Asymmetrical Nine Phase Delta-Connected Transformer for HVDC Transmission

Arafet Ben Ammar

Faouzi Ben Ammar

Vol. 18, No. 6, pp. 1920-1929, Nov. 2018

10.6113/JPE.2018.18.6.1920

18-pulse ac-dc converters

Asymmetrical autotransformer

LCC-HVDC

Thyristor

THD current

PDF Full-Text

Abstract

In order to provide a source for nine phases suitable for 18-pulse ac to dc power, this paper proposes a new structure for a step-up asymmetrical delta-connected transformer for converting three-phase ac power to nine-phase ac power. The design allows for symmetry between the nine output voltages to improve the power quality of the supply current and to minimize the THD. The results show that this new structure proves the equality between the output voltages with 40°- α and 40°+ α phase shifting and produces symmetrical output currents. This result in the elimination of harmonics in the network current and provides a simulated THD that is equal to 5.12 %. An experimental prototype of the step-up asymmetrical delta-autotransformer is developed in the laboratory and the obtained results give a network current with a THD that is equal to 5.35%. Furthermore, a finite element analysis with a 3D magnetic field model is made based on the dimensions of the 4kVA, 400 V laboratory prototype three-phase with three-limb delta-autotransformer with a six-stacked-core in each limb. The magnetic distribution flux, field intensity and magnetic energy are carried out under open-circuit operation or load-loss.

Statistics

Show / Hide Statistics

Cumulative Counts from September 30th, 2019
Multiple requests among the same browser session are counted as one view. If you mouse over a chart, the values of data points will be shown.

Cite this article

[IEEE Style]

A. B. Ammar and F. B. Ammar, "Step-Up Asymmetrical Nine Phase Delta-Connected Transformer for HVDC Transmission," Journal of Power Electronics, vol. 18, no. 6, pp. 1920-1929, 2018. DOI: 10.6113/JPE.2018.18.6.1920.

[ACM Style]

Arafet Ben Ammar and Faouzi Ben Ammar. 2018. Step-Up Asymmetrical Nine Phase Delta-Connected Transformer for HVDC Transmission. Journal of Power Electronics, 18, 6, (2018), 1920-1929. DOI: 10.6113/JPE.2018.18.6.1920.