電氣盤體盤內反應譜放大因子試驗研究

An experimental study on amplification factors for in-cabinet response spectrum of Motor Control Center

陳明毅(Ming-Yi Chen)

指導教授 ： 黃尹男

國立臺灣大學/工學院/土木工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.01268

摘要

根據龍門電廠期末安全分析報告(FSAR)之耐震風險評估分析結果發現，對爐心受損年平均頻率貢獻最高之主要因素，為AC獨立消防補水系統與餘熱移除系統C串共用之管路系統失效，而控制餘熱移除系統C串之設備物放置在MCC電氣盤體(Motor Control Center, MCC)中，該設備之耐震需求，取決於MCC盤體之盤內反應。MCC電氣盤體即為本研究之研究對象。
本研究藉由振動台試驗探討三種不同類型之MCC電氣盤體於質量、設備安裝位置、輸入波大小及類型等參數改變下對盤內反應譜以及盤內放大因子之影響，基於振動台試驗結果得知，盤內為抽屜型式之MCC電氣盤體之動力放大因子(AF)較無抽屜的高，並因碰撞而於高頻區段產生遠大於低頻區段之反應。此外，主要影響機櫃反應之因素為設備物所放置之高度、輸入波強度及輸入波類型。並依據振動台試驗之結果與現行規範比較，比較結果發現AF值3.0對於三種機櫃X方向低頻之反應為一保守值，對於Y方向低頻反應容易產生不保守之情形，而且高頻反應之峰值遠大於AF值3.0估算之峰值，若高頻反應會導致盤內設備物損壞，則AF值3.0有不保守之疑慮。
本研究利用有限元素分析軟體(SAP2000)建立機櫃簡化數值模型，並與振動台試驗結果進行比對，結果發現若能掌握機櫃隨地表運動強度增加所造成機櫃動力性質之變化，簡化模型能精準地模擬機櫃盤內低頻部分之受震反應，若配合機櫃內部面板模型，則可改進簡化模型對機櫃盤內高頻反應之預測誤差。此數值模型可供往後進行參數分析及估算盤內反應譜。

關鍵字

MCC電氣盤體 ； 盤內反應譜 ； 盤內設備物 ； 動力放大因子 ； 數值模型

並列摘要

In this study, shake table tests and numerical simulations were performed to evaluate seismic demands of in-cabinet instruments installed in sample cabinets of Motor Control Center (MCC) in the Lungmen Nuclear Power Plant.
The impact of the following factors on in-cabinet responses of the sample MCC were investigated using shake table tests, including cubicle types, input motions, existence of simulated mass for in-cabinet instruments, and the locations of measuring points. The tests results show that the values of amplification factor (AF) of cabinets with drawers were higher than the ones without drawers, especially in the high frequency range, due to the impact between drawers and cabinet components. Compared with the observed AF values in the low frequency range along the side-to-side (X) direction of the tested cabinets, the AF value of 3.0 recommended in EPRI NP-6041 is conservative. However, the prescribed value is unconservative compared with the observed values of AF in the high frequency range along the front-to-back (Y) direction.
A simplified procedure was proposed in this study to estimate the in-cabinet response spectrum (ICRS) of MCC cabinets without drawers. In the procedure, an MCC cabinet was simulated as a lumped-mass stick to capture its global responses and the vertical panel at which instruments were anchored in the cabinet were modeled separately and in detail using finite element program. The ICRS was then computed using the response of the detailed finite element model for the vertical panel subjected to the acceleration history of the node in the lumped–mass model at the location of the vertical panel. The effectiveness of this procedure was verified by the results of shaking table tests.

並列關鍵字

MCC ； in-cabinet response spectrum ； amplification factor ； stick model

參考文獻

Bandyopadhyay, K. K., et al. (1988). "Dynamic Amplification of Electrical Cabinets," NUREG/CR-5203, Brookhaven National laboratory (BNL), Upton, New York.

Cho, S. G., Kim, D., and Chaudhary, S. (2011). "A simplified model for nonlinear seismic response analysis of equipment cabinets in nuclear power plants." Nuclear Engineering and Design, 241(8), 2750-2757.

Gupta, A., Rustogi, S., and Gupta, A. K. (1999). "Ritz vector approach for evaluating incabinet response spectra." Nuclear engineering and design, 190(3), 255-272.

Gupta, A., and Yang, J. (2002). "Modified Ritz vector approach for dynamic properties of electrical cabinets and control panels." Nuclear engineering and design, 217(1), 49-62.

Kim, M. K., Choi, I.-K., and Seo, J.-M. (2012). "A shaking table test for an evaluation of seismic behavior of 480V MCC." Nuclear Engineering and Design, 243, 341-355.