含DG配电网的不确定性谐波潮流计算

发布时间：2018-06-04 08:40

本文选题：谐波潮流 + 谐波水平　；参考：《天津大学》2014年硕士论文

【摘要】：谐波潮流计算是电力系统谐波分析的重要手段。通过计算可获得系统的谐波分布情况,为电网的谐波治理提供依据。但目前用于谐波分析的谐波潮流算法多为确定性算法,无法对系统中的不确定因素进行分析。配电网负荷种类繁多、变化频繁,并且日益增多的分布式电源(DG)受天气等因素的影响,出力具有更大的间歇性和随机性,这直接导致了非线性负荷节点注入谐波电流具有不确定性,进而导致配电网的谐波分布具有不确定性。本文建立了谐波源的恒流源复仿射模型,以区间代替点值表示谐波源的不确定信息。考虑到前推回代算法能高效计算辐射型配电网潮流,以及复仿射数学能克服区间数学固有的保守性,提出了配电网三相不确定谐波潮流的前推回代复仿射算法。采用典型配电系统算例对算法进行了验证,将蒙特卡罗谐波潮流分析方法与所提算法的计算结果进行了对比,从完备性、保守性、收敛性和计算速度四个方面对所提算法进行了评估。提出了含DG配电网的谐波潮流算法。由于DG多通过并网逆变器接入配电网,将与配电网产生相互作用,对电网谐波分布造成影响,故以并网逆变器的输出阻抗模型对DG建模,并用于谐波潮流计算,可计及电网结构、电网背景谐波、DG接入位置等多方面因素。针对典型配电系统算例分别计算了DG采用输出阻抗模型和恒流源模型时的谐波潮流,对含DG配电网的谐波分布以及DG注入谐波电流进行了计算分析,研究了DG接入位置、电网谐波水平等对DG注入谐波电流以及谐波分布的影响。针对DG出力的不确定性,建立了DG并网逆变器输出阻抗复仿射模型,与谐波源恒流源的复仿射模型同时应用于谐波潮流计算中,提出了含DG配电网的不确定谐波潮流的前推回代复仿射算法。通过典型配电系统算例将算法与蒙特卡罗谐波潮流分析方法的计算结果进行对比,评估了含DG配电网的不确定谐波潮流算法的各项性能。
[Abstract]:Harmonic power flow calculation is an important means of harmonic analysis in power system. The harmonic distribution of the system can be obtained by calculation, which provides the basis for the harmonic treatment of the power network. However, most of the harmonic power flow algorithms used in harmonic analysis are deterministic algorithms, which can not be used to analyze the uncertain factors in the system. There are many kinds of load in distribution network, which change frequently, and more distributed power sources (DGs) are influenced by weather and other factors, so the output power has more intermittence and randomness. This directly leads to the uncertainty of the harmonic current injected by the nonlinear load node and the uncertainty of the harmonic distribution of the distribution network. In this paper, the complex affine model of constant current source of harmonic source is established, and the uncertain information of harmonic source is represented by interval instead of point value. Considering that the forward pushback algorithm can efficiently calculate the radiation distribution network power flow and the complex affine mathematics can overcome the inherent conservatism of interval mathematics, a forward push-back iterative reaffine algorithm for three-phase uncertain harmonic power flow in distribution network is proposed. A typical distribution system example is used to verify the algorithm. The Monte Carlo harmonic power flow analysis method is compared with the calculated results of the proposed algorithm, which is based on completeness and conservatism. The proposed algorithm is evaluated from four aspects: convergence and computational speed. A harmonic power flow algorithm with DG distribution network is proposed. Because DG is connected to distribution network through grid-connected inverter, it will interact with distribution network and affect the harmonic distribution of power network, so the output impedance model of grid-connected inverter is used to model DG, and it is used to calculate harmonic power flow. It can take into account the power network structure, power network background harmonics DG access location and other factors. The harmonic power flow of DG using output impedance model and constant current source model is calculated for typical distribution system examples. The harmonic distribution and DG injected harmonic current in DG distribution network are calculated and analyzed, and the DG access position is studied. The influence of harmonic level on DG injection harmonic current and harmonic distribution. Aiming at the uncertainty of DG output force, the output impedance complex affine model of DG grid-connected inverter is established, which is applied to harmonic power flow calculation at the same time as the complex affine model of harmonic source constant-current source. A forward push-back iterative affine algorithm for uncertain harmonic power flow with DG distribution network is proposed. By comparing the calculation results of the algorithm with the Monte Carlo harmonic power flow analysis method, the performance of the uncertain harmonic power flow algorithm with DG distribution network is evaluated by a typical distribution system example.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM744

【参考文献】