【摘要】：隨著我國(guó)堅(jiān)強(qiáng)智能電網(wǎng)的建設(shè),大規(guī)模新能源發(fā)電場(chǎng)／站大量接入輸電網(wǎng)；高壓直流輸電(high voltage direct current, HVDC)逐漸增多；柔性交流輸電系統(tǒng)(Flexible Alternating Current Transmission System, FACTS)得到廣泛應(yīng)用。上述輸電網(wǎng)的發(fā)展變化對(duì)輸電線繼電保護(hù)的選擇性、靈敏性、可靠性、速動(dòng)性提出了更高要求。另一方面,快速切除超高壓及特高壓輸電線故障,可減小短路電流所產(chǎn)生的較大電動(dòng)力和熱應(yīng)力對(duì)系統(tǒng)設(shè)備造成的不利影響,也是增加輸電線傳輸容量和提高系統(tǒng)暫態(tài)穩(wěn)定的一種有效措施。因此,研究快速、可靠、靈敏動(dòng)作的保護(hù)原理對(duì)于保障電力系統(tǒng)的安全穩(wěn)定運(yùn)行具有重要意義�；诖�,本文對(duì)基于暫態(tài)行波的超高速保護(hù)和基于微分方程算法的快速距離保護(hù)進(jìn)行研究。首先,論文應(yīng)用S變換獲取單頻率行波的時(shí)域分布,提出考慮輸電線傳輸函數(shù)的超高速行波縱聯(lián)單元式保護(hù)。為了精確描述行波在輸電線路上的傳播過(guò)程及其衰減規(guī)律,依據(jù)有損均勻傳輸線的等效二端口網(wǎng)絡(luò)建立故障附加網(wǎng)絡(luò)的集總電路,推導(dǎo)出輸電線兩端初始反向行波的數(shù)學(xué)關(guān)系。利用線路兩端初始反向行波的比值構(gòu)造識(shí)別區(qū)內(nèi)外故障的判據(jù)。故障判據(jù)從原理上克服了線路模型誤差、線路參數(shù)不確定性、波速不一致性等因素產(chǎn)生的不利影響。利用PSCAD/EMTDC仿真數(shù)據(jù)對(duì)保護(hù)算法進(jìn)行了測(cè)試,仿真結(jié)果表明保護(hù)算法能可靠識(shí)別區(qū)內(nèi)外故障。其次,論文在定義視在波阻抗的基礎(chǔ)上,分析了視在波阻抗與母線網(wǎng)絡(luò)波阻抗和正方線路波阻抗之間的關(guān)系,提出了兩種行波方向繼電器。一種是基于視在波阻抗的方向繼電器。依據(jù)母線網(wǎng)絡(luò)波阻抗及正方線路波阻抗分別設(shè)置正、反方向歐姆圓,構(gòu)成雙歐姆圓的方向判據(jù)。系統(tǒng)發(fā)生故障,如果計(jì)算的視在波阻抗位于正方向歐姆圓內(nèi),判斷正方向發(fā)生故障,如果視在波阻抗位于反方向歐姆圓內(nèi),判斷反方向發(fā)生故障。另一種是基于視在波阻抗相角的方向繼電器。由于正方向發(fā)生故障,利用初始行波計(jì)算的視在波阻抗相角大于0.5π(rad);反方向發(fā)生故障,利用初始行波計(jì)算的視在波阻抗相角接近零。依據(jù)視在波阻抗相角的大小可構(gòu)成正、反方向故障判據(jù)。大量的PSCAD/EMTDC仿真實(shí)驗(yàn)結(jié)果表明：提出的兩種方向繼電器能可靠、靈敏、超高速識(shí)別正反方向故障,其性能受故障初始角、故障距離、故障電阻等因素的影響小。再次,論文提出采用希爾伯特-黃變換(hilbert-huang transform, HHT)分解微分方程算法計(jì)算結(jié)果中高頻成分的距離保護(hù)方案。該方案將微分方程算法的結(jié)果構(gòu)成時(shí)間序列,通過(guò)經(jīng)驗(yàn)?zāi)B(tài)分解(empirical mode decomposition, EMD)將序列中代表高次諧波的本質(zhì)模態(tài)函數(shù)(intrinsic mode function, IMF)分離出來(lái),得到具有單調(diào)變化趨勢(shì)的“殘差”,然后根據(jù)“殘差”計(jì)算出故障線路阻抗。仿真結(jié)果表明該方案能在線路故障后快速估算出具有較高精度的故障線路阻抗值。最后,提出了利用基波相量變化率的故障選相方法和雷擊干擾識(shí)別方法。線路發(fā)生短路故障后,故障相基波電流相量變化率受衰減直流分量及工頻故障分量影響,其值迅速增大,而非故障相基波電流相量變化率變化較��；如果發(fā)生接地故障,零序電流基波相量變化率受衰減直流分量及工頻故障分量影響,其值也會(huì)迅速增大,否則其值在零附近波動(dòng)。論文依據(jù)不同類型故障中基波電流相量變化率的特征,提出了利用基波電流相量變化率的故障選相方法。線路發(fā)生短路故障或遭受故障性雷擊,附加電流分量中包含衰減周期分量以及基波故障分量,導(dǎo)致基波電流相量變化率大幅度變化；線路遭受非故障性雷擊,附加電流分量?jī)H包含高頻雷電波,雷擊后一段時(shí)間內(nèi)基波電流相量變化率較小。論文依據(jù)短路故障、故障性雷擊及非故障性雷擊產(chǎn)生的附加電流分量對(duì)基波電流相量變化率的不同影響,提出了利用基波電流相量變化率識(shí)別雷擊干擾的方法。PSCAD/EMTDC仿真結(jié)果驗(yàn)證了所提方法的有效性和可靠性。為了進(jìn)一步利用動(dòng)模實(shí)驗(yàn)或現(xiàn)場(chǎng)在線測(cè)試等方式驗(yàn)證保護(hù)算法是否符合繼電保護(hù)的各種規(guī)范要求,論文采用浮點(diǎn)數(shù)字信號(hào)處理器TMS320C6748設(shè)計(jì)了保護(hù)實(shí)驗(yàn)裝置的硬件,給出了以實(shí)時(shí)操作系統(tǒng)內(nèi)核SYS/BIOS為核心的系統(tǒng)軟件架構(gòu)以及保護(hù)應(yīng)用程序的設(shè)計(jì)方案。對(duì)關(guān)鍵程序及算法進(jìn)行了測(cè)試。
[Abstract]:With the construction of China's strong intelligent power network, large-scale new energy transmission system/ station has a large number of access points; high voltage direct current (HVDC) is increasing gradually; flexible alternating current transmission system (FACTS) has been widely used. The development change of the above-mentioned power supply provides higher requirements for the selectivity, sensitivity, reliability and speed of relay protection of the transmission line. On the other hand, rapid removal of ultra-high voltage and ultra-high voltage transmission line faults can reduce the adverse effect of large electric power and thermal stress generated by short circuit current on the system equipment, and also an effective measure to increase transmission capacity of transmission line and improve transient stability of the system. Therefore, the research on the protection principle of fast, reliable and sensitive action is of great significance to ensure the safe and stable operation of the power system. Based on this, this paper studies fast distance protection based on transient traveling wave and fast distance protection based on differential equation algorithm. Firstly, the paper uses S-transform to acquire the time-domain distribution of single-frequency traveling wave, and puts forward the ultra-high-speed traveling wave longitudinal coupling protection for transmission function of transmission line. In order to accurately describe the propagation process of traveling wave on the transmission line and its attenuation law, the mathematical relation of initial reverse traveling wave at both ends of the transmission line is deduced according to the lumped circuit of the equivalent two-port network of lossy uniform transmission line. Based on the ratio of the initial reverse traveling wave at both ends of the line, the criterion for identifying the inside and outside faults of the identification area is constructed. The failure criterion overcomes the adverse effects of line model error, line parameter uncertainty, wave velocity inconsistency and other factors from the principle. The protection algorithm is tested with PSCAD/ EMTDC simulation data. The simulation results show that the protection algorithm can reliably identify the internal and external faults of the area. Secondly, based on wave impedance, the paper analyzes the relation between wave impedance and wave impedance of bus network, and puts forward two kinds of traveling wave directional relays. The invention relates to a directional relay based on apparent wave impedance. The positive and reverse ohmic circles are respectively set according to the wave impedance of the bus network and the wave impedance of the line, and the direction criterion of the double-ohm circle is formed. If the system fails, if the calculated apparent impedance is in the positive direction ohm circle, it is judged that the positive direction is in fault, and if the wave impedance is in the anti-direction ohmic circle, it is judged that the reverse direction is faulted. The other is based on the direction relay based on the wave impedance phase angle. Due to the fault in the positive direction, the apparent wave impedance phase angle calculated by the initial traveling wave is greater than 0.5dBc (rad); in the reverse direction, the apparent wave impedance phase angle calculated by the initial traveling wave is close to zero. According to the magnitude of the wave impedance phase angle, the positive and reverse direction fault criteria can be constructed. A large number of PSCAD/ EMTDC simulation results show that the two directional relays are reliable, sensitive, super high speed identification positive and negative faults, and their performance is affected by the factors such as initial angle, fault distance and fault resistance. Thirdly, Hilbert-Huang transform (HHT) is used to calculate the distance protection scheme of high-frequency components in the calculation results of differential equations. In this scheme, the result of the differential equation algorithm is divided into the time series, and the intrinsic mode function (IMF) representing the high sub-harmonic in the sequence is separated by empirical mode decomposition (EMD) to obtain the 鈥渞esidual鈥，

本文編號(hào)：2283386