Keywords
definite-time overcurrent protection, Hilbert-Huang transform, current instantaneous frequency characteristics, asynchronous motor starting, intermittent periodic duty
Abstract
The floating crane supply system usually incorporates large-capacity multiple asynchronous motors. During the starting process of these motors, simultaneous activation can result in substantial current surges. Consequently, the transformer bears a heavy current burden, potentially triggering the false overcurrent protection and leading to further industrial production losses. This paper investigates a protection scheme for transformers supplying multiple high-capacity motors. Firstly, the mechanism of the overcurrent during motor starting is analyzed by an equivalent model. Subsequently, a random scenario generating algorithm is proposed to generate a large number of scenarios for analysis. Furthermore, the Hilbert-Huang transform technique is employed to examine the time-frequency domain characteristics of both fault current and normal current, leading to improvements in the conventional overcurrent protection scheme. Finally, The effectiveness of the proposed protection scheme is validated through a realistic floating crane supply project in Hunan province.
DOI
10.19781/j.issn.1673-9140.2024.01.014
First Page
144
Last Page
154
Recommended Citation
CHEN, Bin; ZHU, Shengkai; TANG, Wei; XIAO, Jianping; and WANG, Weiyu
(2024)
"Definite‑time overcurrent protection scheme for floating crane supply system based on the instantaneous frequency characteristics of currents,"
Journal of Electric Power Science and Technology: Vol. 39:
Iss.
1, Article 14.
DOI: 10.19781/j.issn.1673-9140.2024.01.014
Available at:
https://jepst.researchcommons.org/journal/vol39/iss1/14