Research on Overvoltage of Parallel Capacitors in 500kv Substation and its Protection Parameters

Abstract:

In order to make it clear for explosion accidents of parallel capacitors occurred in 500kV substations in Sichuan power network one after another, the authors calculate and analyze the distribution of overvoltage caused by breakdown of elements within the capacitor bank. Dissecting the insulation of faulty capacitors, severe ageing of insulation is discovered; this phenomenon proves that the overvoltage on partial element should be the main factor influencing the insulating performance of capacitors. To ensure the reliable operation of parallel capacitors the setting value of unbalanced current protection at the neutral point of double star connection is modified by the calculated value of unbalanced current of 35kV capacitor bank in which there are six parallel groups of capacitors and in each group seven capacitors are connected in series.

• Periodical: Applied Mechanics and Materials (Volumes 303-306)
• Pages: 1920-1924
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.303-306.1920
• Online since: February 2013
• Authors: Xing Hai Zhang, Bo Wen Zhang, Wei Feng Han, Ji Xing Sun, Guang Ning Wu, Guo Qiang Gao
• Keywords: Insulation Breakdown, Over-Voltage Protection, Parallel Capacitor, Power System, Unbalance Current

References

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