Open AccessNumerical calculation of the lightning transient voltage distribution on converter transformer winding based a dual winding model
Author(s) -
Jia Hongrui,
Liu Xuezhong,
Tian Shijin,
Wang Lin,
Gao Fei
Publication year - 2019
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2018.8458
Subject(s) - autotransformer , forward converter , electrical engineering , flyback converter , distribution transformer , delta wye transformer , transformer , boost converter , transformer effect , engineering , voltage
The insulation co‐ordination of converter transformer winding has a great influence on power system security. An equivalent circuit of a 500 kV converter transformer winding structure, including a LC equivalent network circuit and an ideal transformer in parallel, was firstly established. A combined 12‐pulse rectifier equivalent circuit model, mainly consisting of six single‐phase converter transformer and 12 converter valves, was built in Power Systems Computer Aided Design (PSCAD) software. In certain operating states of the converter value, the transient voltage distribution was analysed when lightning strokes the DC bus of a typical converter station. The results show that the dual winding model can present the transient voltage characteristics of the converter transformer. The maximum lightning transient voltage is located at the end of the star‐connected winding near the neutral point and reaches 1270 kV, and also the maximum gradient voltage occurs at the winding near the terminal point. In different operating states for the converter valve, the transient voltages of a three‐phase winding behave as per the similar distributing rules. For the star‐connected phase winding, the lightning transient voltage of the winding disc reaches the maximum magnitude when lightning strike occurs at the peak of the phase voltage on the valve side.