第 51 卷 第 17 期 電力系統(tǒng)保護(hù)與控制 Vol.51 No.17
2023 年9 月 1 日 Power System Protection and Control Sept. 1, 2023
DOI: 10.19783/j.cnki.pspc.230064
中壓不接地配電網(wǎng)三相潮流新方法
張 逸 1
,林金榕 1
,李傳棟 2
,邵振國(guó) 1
,藍(lán) 天 1
,陳書(shū)暢 1
(1.福州大學(xué)電氣工程與自動(dòng)化學(xué)院,福建 福州 350108;2.國(guó)網(wǎng)福建省電力有限公司
電力科學(xué)研究院,福建 福州 350007)
摘要:在大量分布式電源接入中低壓配電網(wǎng)的新形勢(shì)下,三相潮流計(jì)算是分析其影響的基本手段。針對(duì)現(xiàn)有中壓
不接地配電網(wǎng)三相潮流研究主要采用人為設(shè)置參考中性點(diǎn)/零序電壓的方式,導(dǎo)致無(wú)法仿真分析中性點(diǎn)/零序電壓
偏移、不接地網(wǎng)絡(luò)零序潮流和相-地電壓不平衡等情況,提出一種中壓不接地配電網(wǎng)三相潮流新算法。首先,提出
不接地配電網(wǎng)三相潮流在節(jié)點(diǎn)變量和導(dǎo)納矩陣方面的特殊性。然后,設(shè)計(jì)基于功率平衡方程和牛拉法,采用導(dǎo)納
矩陣可逆化處理和矩陣替換技術(shù)實(shí)現(xiàn)約束零序電流為零的不接地配電網(wǎng)三相潮流算法。最后,基于 6 節(jié)點(diǎn)系統(tǒng)和
修改的 IEEE123 算例仿真不接地配網(wǎng)的潮流,結(jié)合 PSCAD 驗(yàn)證所提方法在不同場(chǎng)景下的準(zhǔn)確性以及在大電網(wǎng)中的
適用性和收斂性,并在地市電網(wǎng)中進(jìn)行實(shí)際應(yīng)用。算例分析表明,所提算法計(jì)算結(jié)果準(zhǔn)確,具有良好的工程實(shí)用性。
關(guān)鍵詞:三相潮流;配電網(wǎng);不接地網(wǎng)絡(luò);牛頓-拉夫遜法
A method for three-phase power flow in a medium-voltage ungrounded distribution network
ZHANG Yi1
, LIN Jinrong1
, LI Chuandong2
, SHAO Zhenguo1
, LAN Tian1
, CHEN Shuchang1
(1. College of Electrical Engineering and Automation, Fuzhou University, Fuzhou 350108, China; 2. Electric Power
Research Institute of State Grid Fujian Electric Power Co., Ltd., Fuzhou 350007, China)
Abstract: With a large amount of distributed generation connected to the medium and low voltage distribution network,
three-phase power flow calculation is the basic means to analyze their influence. The existing research on three-phase
power flow for a medium-voltage ungrounded distribution network mainly adopts the method of manually setting the
reference neutral point or zero-sequence voltage. This makes it difficult to simulate and analyze the neutral point or
zero-sequence voltage offset, and the zero-sequence power flow and the imbalance of phase to ground voltage. Thus this
paper proposes a new three-phase power flow algorithm for a medium-voltage ungrounded distribution network. First, the
particularity of three-phase power flow for this network in terms of node variables and admittance matrix is analyzed.
Second, based on a power balance equation and the Newton-Raphson method, a three-phase power flow algorithm for an
ungrounded distribution network with constrained zero-sequence current is designed by using admittance matrix
reversible processing and matrix replacement technology. Finally, the power flow for the ungrounded distribution network
is simulated based on the 6-bus system and the modified IEEE123 test case. The accuracy of the proposed method in
different scenarios and its applicability and convergence in large power grids are verified by PSCAD, and a practical
application is carried out in local power grids. The example analysis shows that the proposed algorithm gives accurate
calculation results and good engineering practicability.
This work is supported by the National Natural Science Foundation of China (No. 51777035).
Key words: three-phase power flow; distribution network; ungrounded network; Newton-Raphson method
0 引言
目前,大量分布式新能源接入中低壓配電網(wǎng),其
運(yùn)行和控制均面臨重大挑戰(zhàn)[1-5]。例如:受到環(huán)境、
基金項(xiàng)目:國(guó)家自然科學(xué)基金項(xiàng)目資助(51777035);福建省
自然科學(xué)基金項(xiàng)目資助(2020J01123)
人為等因素的影響,新能源接入呈現(xiàn)較大的波動(dòng)性
和隨機(jī)性,且大量剩余功率形成逆向潮流,通過(guò)低壓
配網(wǎng)饋入中壓配網(wǎng),易引起中壓配網(wǎng)的電壓越限[6-7]、
三相不平衡[8-9]、失穩(wěn)[10-11]和其他電能質(zhì)量問(wèn)題[12-13]
等。因此,作為分析以上問(wèn)題的基本手段,研究如
何準(zhǔn)確地計(jì)算中壓配電網(wǎng)的三相潮流具有重要意義。
我國(guó) 110 kV 及以上電網(wǎng)一般采用中性點(diǎn)有效