【正文】 效地改善系統(tǒng)電壓穩(wěn)定，以及負(fù)荷大小所需的無功容[2]。在新設(shè)計(jì)的變電所中，由于具有經(jīng)濟(jì)、維護(hù)和安裝的優(yōu)點(diǎn)，本站也采用電容補(bǔ)償裝置。電容器的電壓不能突變，流過的電流可以突變，而電感器的電流不能突變。，參數(shù)如下表：型號(hào)額定電壓額定容量相數(shù)15001補(bǔ)償接線圖如圖52 圖52無功補(bǔ)償接線圖 本章小結(jié)無功補(bǔ)償是保證電壓質(zhì)量的重要因素，在地區(qū)性變電站中又顯得十分重要，它有利于改變?cè)撾妳^(qū)的電壓質(zhì)量。2）設(shè)計(jì)出站用電接線形式和備用電源方案。本設(shè)計(jì)只是理論上的設(shè)計(jì)，離實(shí)際工程設(shè)計(jì)還很遠(yuǎn)，而且本設(shè)計(jì)只涉及到一次部分，沒有提到二次部分，所以設(shè)計(jì)還不完善，有一定的漏洞。這兩種方法存在兩個(gè)本質(zhì)區(qū)別。*可以輕松考慮到網(wǎng)絡(luò)組件的多故障模型，例如在變電所結(jié)構(gòu)中組件的積極，消極故障1，2.*可預(yù)料的操作行動(dòng)。變電站的可靠性可以使用蒙特卡洛仿真法或者分析法進(jìn)行評(píng)估17。第二，割集枚舉只包含故障部分，而網(wǎng)絡(luò)狀態(tài)枚舉包括故障部分和正常部分。前三個(gè)特點(diǎn)是由于網(wǎng)絡(luò)狀態(tài)枚舉法重點(diǎn)關(guān)注可以輕松涉及包含操作轉(zhuǎn)換和串聯(lián)故障在內(nèi)的任何變電所結(jié)構(gòu)狀態(tài)的整個(gè)網(wǎng)絡(luò)。總線負(fù)載的損失負(fù)載作為變電所網(wǎng)絡(luò)故障標(biāo)準(zhǔn)。使用割集枚舉，確定四個(gè)最小割集數(shù)：S1 = (T1, T2}。第二個(gè)等式的左右兩邊表明與最小割集數(shù)取交集。通常，盡管網(wǎng)絡(luò)狀態(tài)枚舉數(shù)要比最小割集數(shù)多，但使用標(biāo)記總線程序它可以更方便快捷的確定它們。例如，設(shè)U=，. 同時(shí)考慮開路和短路故障對(duì)于割集枚舉法來說，與短路故障結(jié)合的合并從屬故障，多重故障模式和轉(zhuǎn)換行為非常困難，需要變電站構(gòu)造可靠性評(píng)估的模式化。這就導(dǎo)致了轉(zhuǎn)換狀態(tài)。這第二種狀態(tài)相當(dāng)于修復(fù)故障變壓器狀態(tài)。對(duì)母線連接情況的說明是為了提出并解釋第三部分中使用的變電站配置。關(guān)鍵是要確定一個(gè)網(wǎng)絡(luò)狀態(tài)的列舉是否是一個(gè)失敗的或不存在的例子。該網(wǎng)絡(luò)的一個(gè)變電站的例子表明，在只考慮開路故障時(shí)，使用該方法和最小割集的方法得到相同的結(jié)果。S4 = {B2, B3, T1). The probability of substation network failure is calculated by Fig. 4. A simple substation network.Pf = P(S1 ∪ S2 ∪ S3 ∪ S4) = 2U2 + 2U3 ? 5U4 + 2U5 (4)As usual, the four minimum cut sets are not mutually exclusive. The calculations from the left side of the second equality sign to its right side are associated with intersections among the minimum cut sets. For this simple case, it can be expressed asfollows:Pf = P(S1 ∪ S2 ∪ S3 ∪ S4)= P(S1) + P(S2) + P(S3) + P(S4) ? P(S1 ∩ S2)?P(S1 ∩ S3) ? P(S1 ∩ S4) ? P(S2 ∩ S3) ? P(S2 ∩ S4)?P(S3 ∩ S4) + P(S1 ∩ S2 ∩ S3) + P(S1 ∩ S2 ∩ S4)+P(S1 ∩ S3 ∩ S4) + P(S2 ∩ S3 ∩ S4)?P(S1 ∩ S2 ∩ S3 ∩ S4) (5)For a relatively large network, identifying all minimum cut sets and performing calculations of the union of nonmutually exclusive cut sets require considerable putational efforts. Using the presented network state enumeration with the labeling bus set approach, 16 network states are identified as failure states that lead to loss of load. Generally, although the number of network failure states is more than the number of minimum cut sets, it is much easier and faster to identify them using the labeling bus set approach in programming. Particularly, once the network failure states are identified, the total network failure probability is just the sum of probabilities of all network failure states without any calculation associated with the union and intersections. In this example, we can have the following analytical expression of substation network failure probability:Pf = 2U2(1 ? U)3 + 8U3(1 ? U)2 + 5U4(1 ? U) + U5 (6)It is interesting to note that Eqs. (4) and (6) look so different but they lead to the same result. This can be proven by assign Ua value. For instance, by letting U= , the substation network failure probability from both the equations is identical, which is.. Considering both open circuit failures and shortcircuit faultsIt is relatively difficult for the cut set method to incorporate dependent failure events, multiple failure modes and switching actions, which are associated with short circuit faults and need to be modeled in reliability evaluation of a substation configuration.It has been assumed in this example that the breakers can clear their own short circuit faults and only the short circuit faults on the two transformers are considered. When a short circuit fault happens on either transformer, the breakers B1 and B2 will be opened by a protection action. This results in a switching state. In this state, B1 and B2 are still healthy ponents. Their outages are not due to a failure and cannot be treated as ponents in a cut set. Then, the switches (not shown in the figure) at both sides of the failed transformer are manually opened to isolate it, and B1 and B2 are reclosed so that the load may be supplied through another transformer if the second transformer is not simultaneously down. This second state corresponds to a repairing state of the faulted transformer.3. ConclusionsThe network state enumeration technique bined with the labeling bus set approach proposed in the paper is suitable for reliability evaluation of a substation configuration or a looped distribution network that needs to model dependent failures, multiple failure modes and multiple states of ponents.Another advantage of the presented network state enumeration technique is that enumerated network states are mutually exclusive resulting in great simplification in calculating the total network failure probability pared to the minimum cut set method. The key in the presented technique is identification of whether a state is a failure one or not. The labeling bus set approach has been proposed for this purpose. A substation configuration is used to explain the procedure including a switching action associated with dependent outages and multiple states of network ponents. The presented method is easy to program and can be applied to any substation or looped distribution networks.The example of a substation network demonstrates that in the case of considering only open circuit failures, the same result is obtained using the proposed method and the minimum cut set method. The example also shows that the presented technique can handle the case of considering both open failures and short circuit faults which are associated with switching actions and protection logic.燕山大學(xué)本科生畢業(yè)設(shè)計(jì)（論文） 燕山大學(xué)畢業(yè)設(shè)計(jì)（論文）評(píng)審意見表指導(dǎo)教師評(píng)語：成績(jī)： 指導(dǎo)教師簽字： 年 月 日評(píng)閱人評(píng)語： 成績(jī)： 評(píng)閱人簽字： 年 月 日燕山大學(xué)畢業(yè)設(shè)計(jì)（論文）答辯委員會(huì)評(píng)語表答辯委員會(huì)評(píng)語：總成績(jī)： 答辯委員會(huì)成員簽字： 答辯委員會(huì)主席簽字： 年 月 日