【摘要】：隨著電力電子技術的飛速發(fā)展和社會對節(jié)能的關注,電力系統(tǒng)中以橋式整流電路為電源的非線性負荷應用日益增多。這些負荷在低壓電網(wǎng)中廣泛而隨機地分布,導致諧波問題日益嚴重,影響電網(wǎng)的安全運行并引起電能質量下降。為了減少諧波污染,改善電氣環(huán)境,對于數(shù)量龐大的非線性負荷,研究其諧波源污染責任的衡量指標并建立適當?shù)哪Ｐ蛠硌芯恐C波源參數(shù),是完善獎懲機制、制定諧波抑制策略、估計諧波發(fā)射水平的重要條件。首先,在現(xiàn)有諧波污染責任指標尚難以滿足諧波管理獎懲機制執(zhí)行的分析基礎上,提出了用被關注供電支路在PCC點處等效特定次諧波源的視在功率相對于該供電支路傳輸?shù)幕ㄒ曉诠β实谋戎礢si,h* = Ssi,h / Ssi,l=Zsi,h*Isi,h2/Ssi,l 作為衡量污染強度的指標。這一指標表明諧波源對配網(wǎng)的危害主要取決于諧波電流發(fā)射強度和諧波阻抗,同時也真實地、定量地反映了諧波源對PCC點的諧波污染能力,有益于獎懲的量化實施、執(zhí)行,有利于指導諧波的補償,既適用于復雜網(wǎng)絡的等值諧波源,也適用于單個非線性用電設備諧波源。其次,本文基于諾頓等效電路研究諧波源的參數(shù),提出了一種新的元件模型,即“非線性負荷等效成一個受控電流源和等效阻抗的并聯(lián)”,采用“波動量法”探尋了元件模型參數(shù)的影響因素。多種條件下的仿真實驗結果表明,系統(tǒng)在特定情況(觸發(fā)角恒定)下可用諾頓電路等效,非線性元件等效諧波源是一個受控源,同時還會受到阻抗角的影響。推而廣之,在特定狀態(tài)下,不管是非線性元件還是含多個非線性元件的負荷群,或說是一個等效單端口網(wǎng)絡,均可以用“諾頓等效電路”或者“戴維南等效電路”來描述。最后,本文從數(shù)學理論的角度指出“非干預式”測量方法不適用于估計諧波源參數(shù),并舉例進行說明。
[Abstract]:With the rapid development of power electronics technology and the attention of the society to energy saving, the nonlinear load application of bridge rectifier circuit in power system is increasing day by day. These loads are widely and randomly distributed in the low-voltage power network, which leads to the problem of harmonics becoming more and more serious, which affects the safe operation of the power network and causes the decline of the power quality. In order to reduce harmonic pollution and improve electrical environment, for a large number of nonlinear loads, it is necessary to study the measurement index of harmonic source pollution responsibility and establish appropriate model to study harmonic source parameters, which is to perfect the reward and punishment mechanism. Make harmonic suppression strategy and estimate the important condition of harmonic emission level. First of all, on the basis of the analysis that the existing harmonic pollution liability index is still difficult to meet the harmonic management reward and punishment mechanism, The ratio Ssi,h* = Ssi,h / Ssi,l=Zsi,h*Isi,h2/Ssi,l of the apparent power relative to the fundamental wave apparent power transmitted by the concerned power supply branch at the PCC point equivalent to that of the specific sub-harmonic source is proposed as an index to measure the pollution intensity. This index indicates that the harm of harmonic source to distribution network mainly depends on the harmonic current emission intensity and harmonic impedance. At the same time, it reflects the harmonic pollution ability of harmonic source to PCC points, and is beneficial to the quantitative implementation and execution of rewards and punishments. It is beneficial to direct harmonic compensation, which is suitable for both the equivalent harmonic source of complex network and the harmonic source of single nonlinear electrical equipment. Secondly, based on the Norton equivalent circuit to study the parameters of harmonic source, a new component model is proposed, that is, "nonlinear load is equivalent to a controlled current source and equivalent impedance in parallel". The influence factors of the component model parameters are explored by the fluctuation method. The simulation results under various conditions show that the system can be equivalent to Norton circuit under certain conditions (constant trigger angle), and the equivalent harmonic source of nonlinear elements is a controlled source, which is also affected by impedance angle. By extension, in a given state, whether a nonlinear element or a load group containing multiple nonlinear elements, or an equivalent single-port network, can be described as a "Norton equivalent circuit" or "Davinan equivalent circuit". Finally, from the point of view of mathematical theory, this paper points out that the "non-intervention" measurement method is not suitable for estimating harmonic source parameters, and an example is given to illustrate this method.
【學位授予單位】：中國礦業(yè)大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TM711

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本文編號：2218086