本文關(guān)鍵詞： 交流電弧爐 電弧模型 背景諧波 諧波分析　出處：《東南大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著世界經(jīng)濟和科技的發(fā)展,非線性負荷的數(shù)量、種類和用電量與日俱增。這些非線性負荷不可避免地會產(chǎn)生諧波,導(dǎo)致電網(wǎng)電壓畸變率的上升,對輸電線路、電氣設(shè)備、通訊設(shè)備造成不利影響,甚至?xí)痣娏υO(shè)備損壞和電網(wǎng)安全事故。因此,對電力系統(tǒng)諧波進行研究是非常緊迫和有必要的。近年來,在煉鋼業(yè)和冶煉技術(shù)飛速發(fā)展的同時,越來越多的電弧爐設(shè)備被應(yīng)用于金屬冶煉行業(yè),其容量也越來越大,逐漸成為電網(wǎng)中一種重要的諧波源,所以,對電弧爐諧波進行分析和研究具有很大的實際意義。在分析電弧爐之前,應(yīng)該充分了解它的工作原理和特點,并建立起合適的理論模型。本文首先簡述了電弧爐的發(fā)展過程,結(jié)合其煉鋼原理分析了熔化期、氧化期和還原期的工作特點,闡述了它給電力系統(tǒng)帶來的諧波、電壓閃變、三相不平衡、功率因數(shù)低、影響電氣設(shè)備正常工作等問題,并針對電弧爐諧波問題簡單介紹了目前常用的幾種諧波分析方法。在上述工作的基礎(chǔ)上,詳細分析了電弧爐交流電弧的物理特性和其電氣系統(tǒng)各模塊的簡化等效電路,推導(dǎo)了交流電弧相應(yīng)的電阻性模型及其電氣系統(tǒng)的狀態(tài)方程,最后針對交流電弧電阻模型的各個參數(shù),給出了可行的估算方法。接著,論文從兩個方面開展研究了電弧爐建模及其對電網(wǎng)影響的研究。論文建立了一種交流電弧爐時域等效電壓源模型,先基于分段線性化的方法對電弧爐V-Ⅰ特性曲線進行線性化,考慮電弧爐實時有功,可以推導(dǎo)出電弧爐的靜態(tài)模型,適用于電弧爐諧波分析；在電弧爐電阻的靜態(tài)模型上,疊加正弦信號或白噪聲隨機信號,可以推導(dǎo)出適用于電壓波動和閃變研究的,反映電弧爐動態(tài)特性的動態(tài)模型�；赑SCAD完成了模型搭建,仿真結(jié)果符合實際測量的電弧電壓動態(tài)特性,從而證明了該模型的準確性。論文建立了考慮背景諧波的含電弧爐電力系統(tǒng)模型,進行諧波分析。采用PSCAD自帶電弧爐和基于諧波電流源的電弧爐兩種建模方法,基于某煉鋼廠實測數(shù)據(jù),仿真獲得背景諧波電源出口處電壓和電弧爐接入點電壓,對這兩點的電壓進行三相傅里葉分解,從而進行諧波分析。通過仿真結(jié)果可以得出：電弧爐諧波注入會導(dǎo)致電網(wǎng)電壓發(fā)生畸變,而且這種畸變通常是三相不對稱的。
[Abstract]:With the development of the world economy and science and technology, the number, variety and power consumption of nonlinear loads are increasing. These nonlinear loads will inevitably produce harmonics, which will lead to the rise of the voltage distortion rate of the power network, and to the transmission lines, electrical equipment, Communication equipment causes adverse effects, and even causes power equipment damage and power network safety accidents. Therefore, it is very urgent and necessary to study the harmonic of power system. In recent years, with the rapid development of steelmaking and smelting technology, More and more electric arc furnace equipments are used in the metal smelting industry, and their capacity is becoming more and more large, which gradually becomes an important harmonic source in the power grid, so, It is of great practical significance to analyze and study the harmonics of the EAF. Before analyzing the EAF, it is necessary to fully understand its working principle and characteristics, and to establish a suitable theoretical model. Firstly, the development process of EAF is briefly described in this paper. Based on its steelmaking principle, the working characteristics of melting, oxidation and reduction periods are analyzed, and the problems such as harmonics, voltage flicker, three-phase imbalance, low power factor and influence on the normal operation of electrical equipment are expounded. Based on the above work, the physical characteristics of AC arc of arc furnace and the simplified equivalent circuit of each module of electric system are analyzed in detail. The resistance model of AC arc and the state equation of electrical system are derived. At last, a feasible estimation method for each parameter of AC arc resistance model is given. In this paper, the modeling of arc furnace and its influence on power network are studied from two aspects. A time-domain equivalent voltage source model of AC arc furnace is established. Firstly, the V- 鈪，

本文編號：1498729