【正文】 一般情況下，節(jié)點導納矩陣的對角元素往往大于非對角元素的負值； 3）節(jié)點導納矩陣一般是對稱矩陣，這是網絡的互易特性所決定的。由此可見 ,節(jié)點 j、 i 之間的互導納 jiY數(shù)值上就等于連接節(jié)點 j、 i支路導納的負值。網絡中沒有接地支路時 ,各節(jié)點電壓可指各該節(jié)點與某一個被選定作參考節(jié)點之間的對地電壓差。 兩端電壓相等 ?aI? 3I?? ?3I? 圖 兩端電壓相等 aI? ：流經阻抗 12Z 的電流 2I? ， 3I? ：節(jié)點 2,3 的注入電流 用簡化的回路電流法解該簡化等值電路 則NUSI *?? 通過近似方法，從功率中求取相應的電流，電壓近似認為是額定電壓 ,運算負荷2~S , 3~S 的符號與 注入功率及注入電流的符號相反，則： 0)()( 323122312 ?????? IIIZIIZIZ aaa ??????的功率，為流經阻抗 1231*23*12*331*231*23*3*2**312**23*12~~)(~0)()(ZZZZSZSZZSSSSZSSZSZaaaa???????????123z 1 2z 3 1 z 2 3河南城建學院本科畢業(yè)設計（論文） 簡單電力系統(tǒng)潮流計算 8 相似的 bS~ =31*23*12* 331*231*23* ~~)(ZZZSZSZZ???? 兩端電壓不相等 圖 兩端電壓不相等 回路電壓為 0 的單一環(huán)網等值于兩端電壓大小相等、相位相同的兩端供電網絡。 輻射型網絡的手工潮流計算方法 所謂輻射型網絡就是單電源供電的非環(huán)形網絡，系統(tǒng)中所有的負荷都由一個電源供電，輻射型網絡是由若干個簡單支路樹枝狀串級聯(lián)接而成的。因此任何復雜的潮流計算都是從一個簡單支路的潮流分布和電壓降落的計算開始的。在計算要求相同的情況下 , 使用 MATLAB 編程 , 工作量河南城建學院本科畢業(yè)設計（論文） 引言 3 將會大為減少。非線性代數(shù)方程組的解法離不開迭代，因此，潮流計算方法首先要求它是能可靠的收斂，并給出正確答案。 50 年代中期，美國學者 Ward 和 Hale 應用節(jié)點形式的數(shù)學模型取得了成功，基于節(jié)點導納矩陣的迭代算法，即 G— S(高斯 — 賽德爾 )迭代問世。同時，為了 實時監(jiān)控 電力系統(tǒng)的運行狀態(tài)，也需要進行大量而快速的潮流計算。 河南城建學院本科畢業(yè)設計（論文） Abstract II Abstract Power system load flow calculation is the most basic and monly used calculations. Given according to the system operating conditions, the work connection and device parameters can be determined by power flow calculation of the bus voltage (magnitude and phase angle), the power flowing through the ponents, overall system power consumption and so on. Flow calculation is to achieve economic development of power system supply the necessary means and important part of the work. Therefore flow calculation in power system planning and design, production and operation, scheduling management, and scientific research have a wide range of applications. The main purpose of this design is for the general electricity work, the formation of the node admittance matrix, determine the appropriate method, the preparation of generalpurpose puter program to get results. Introduces the design and the PQ deposition Newton Raphson two algorithms, PQ deposition although the structure is more streamlined than the Newton method, but for the general work of modern puter storage space and puting speed has been very strong, in view of the Newton Familiar with its intuitive algorithm, this design in programming using Newton Raphson polar form. The process of solving equations using matlab powerful puting capabilities, the preparation of M language, a reasonable set variables, to achieve generalpurpose puting functions. Keywords: power system, power flow calculation, Newton Raphson method, Matlab. 河南城建學院本科畢業(yè)設計（論文） 目錄 III 目錄 摘 要 .............................................................................................................................. I Abstract .............................................................................................................................. II 目錄 .................................................................................................................................. III 1 引言 ................................................................................................................................. 1 潮流計算目的 ......................................................................................................... 1 潮流計算意義 ......................................................................................................... 1 潮流計算發(fā)展史 ..................................................................................................... 1 基于 MATLAB 的電力系統(tǒng)潮流計算發(fā)展前景 ......................................................... 2 2簡單電力系統(tǒng)潮流計算 ...................................................................................................... 4 ........................................................................................ 4 ................................................................... 4 輻射型網絡的手工潮流計算方法 .................................................................. 6 簡單環(huán)網的潮流計算 ............................................................................................... 7 兩端電壓相等 ................................................................................................ 7 兩端電壓不相等 ............................................................................................. 8 3 復雜電力系統(tǒng)潮流計算的計 算機算法 .............................................................................. 10 ...................................................................................... 10 ...................................................................................... 11 ........................................................................................................... 14 PQ節(jié)點 ................................................................................................... 14 PV節(jié)點 ................................................................................................... 14 平衡節(jié)點 ............................................................................................... 14 .......................