本文關鍵詞：基于改進的重要抽樣算法的輸電系統(tǒng)可靠性評估　出處：《華北電力大學》2015年碩士論文　論文類型：學位論文

  更多相關文章： 輸電系統(tǒng) 可靠性評估 蒙特卡洛法 改進的重要抽樣法

【摘要】：隨著經濟社會的發(fā)展,各行各業(yè)電力用戶對供電可靠性的要求越來越高,發(fā)生停電故障給人類帶來的負面影響也就越來越大,保證安全可靠供電是電力系統(tǒng)的重中之重。面對結構日趨復雜的輸電網絡,客觀、準確、快速地對系統(tǒng)可靠供電能力進行評估,可以全面評價電網可靠性,找到系統(tǒng)的可靠性薄弱環(huán)節(jié),為電力系統(tǒng)規(guī)劃、運行和改進提供數據支持,有著重要的意義。在各種可靠性評估方法中,蒙特卡洛法的應用最為廣泛,尤其適用于大型電力系統(tǒng)的可靠性評估計算,因為其抽樣次數與系統(tǒng)的規(guī)模無關。然而該方法最大的問題在于,要想獲得較高精度的可靠性指標需要進行大量的抽樣計算,這種計算精度和計算速度之間的矛盾很大程度上限制了可靠性評估在實際運用時的收斂速度。針對蒙特卡洛法的這一問題,學者們提出了各種旨在通過降低方差加快收斂速度的抽樣算法,其中被認為最有效的是重要抽樣法。該方法通過把系統(tǒng)內元件的強迫停運率擴大k倍,實現對元件失效情況的放大,提高抽樣效率。然而該方法通常被用于元件故障率相對較高的發(fā)電系統(tǒng),在現實輸電系統(tǒng)中,元件故障率較低、網絡可靠性較好,通過迭代求取最優(yōu)乘子k的算法收斂效果并不明顯,限制了該方法在輸電網絡工程中的應用。本文在對以上問題進行分析的基礎上,提出了適用于實際輸電系統(tǒng)的改進重要抽樣法：在重要抽樣的基礎上對最優(yōu)乘子k的取值和修正方式進行改進,將抽樣分為預抽樣和正式抽樣兩步,通過對小樣本的預抽樣確定k的取值,然后正式抽樣計算系統(tǒng)的可靠性指標。分別應用常規(guī)蒙特卡洛法、重要抽樣法和改進的重要抽樣法,對可靠性測試系統(tǒng)RBTS和IEEE-RTS的輸電部分進行可靠性計算,分析比對計算結果和計算精度,驗證了改進算法的準確性和高效性。為了測試改進算法在工程應用中的適用性,以某地區(qū)實際電網M為研究對象,分別用上述三種方法計算該電網整體以及各節(jié)點的可靠性指標,對比計算結果和精度,證明改進算法在實際工程中應用良好。最后,以該算法計算結果為基礎,結合M電網拓撲結構和元件參數特點,找出該地區(qū)電網可靠性薄弱的環(huán)節(jié),提出改進可靠性的方案,并驗證了這些方案的有效性。
[Abstract]:With the development of economy and society, all walks of life power users on power supply reliability of the increasingly high demand, the negative impact of power outage brought to mankind is more and more big, to ensure safe and reliable power supply is the priority among priorities of the power system. In the face of the transmission network, the increasingly complex structure of objective, accurate, fast and reliable to evaluate power supply system, a comprehensive evaluation of reliability of power grid, find the weakness of system reliability for power system planning, operation and provide data support to improve, has important significance. In the evaluation of various methods of reliability, Monte Carlo method is the most widely used, especially suitable for reliability assessment of power system calculation, because the sampling the number and the scale of the system. However, this method is not the biggest problem, in order to obtain the reliability index of high precision required a lot of sampling This calculation, the contradiction between computational accuracy and computational speed greatly limits the reliability evaluation of the convergence speed in practical application. In order to solve the problem of Monte C Lofa, scholars have put forward various aims to reduce the variance of sampling algorithm to speed up the convergence rate, which is considered the most effective is the important sampling method. By this method the the system components of the forced outage rate of expansion of K times, to achieve amplification of component failure, improve the sampling efficiency. However, this method is usually used for power system component failure rate is relatively high, in the real transmission system, component failure rate is low, the network reliability, through the iterative convergence results from optimal multiplier K is not obvious, which restricts the application of this method in transmission network engineering. Based on above analysis, put forward for the actual transmission The improvement of the system of importance sampling method: Based on importance sampling on optimal value K and correction method was improved, the sample is divided into pre sampling and formal sampling two step, to determine the value of K by pre sampling of small samples, then the formal sampling calculation system reliability index using conventional Monte Carlo method respectively. And the importance sampling method and improved important sampling method, the transmission part of the reliability testing system of RBTS and IEEE-RTS for the calculation of reliability, analysis and comparison of calculation results and calculation accuracy, verify the accuracy and efficiency of the improved algorithm. In order to improve the applicability of the algorithm in the engineering application of the test in the practical power system M as the research object the whole power grid were calculated, and the reliability index of each node by the above three methods, comparing the results of calculation and accuracy in practical engineering shows that the improved algorithm should be used. Finally, based on the calculation results of the algorithm, combined with the characteristics of M power network topology and component parameters, we find out the weak links of the power grid in this area, and put forward the scheme of improving reliability, and verify the effectiveness of these schemes.

【學位授予單位】：華北電力大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TM732

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本文編號：1417526