典型非线性负荷接入电网电能质量特性分析与评估

发布时间：2018-03-26 08:55

本文选题：电能质量　切入点：非线性负荷　出处：《华北电力大学》2014年硕士论文

【摘要】：随着非线性负荷以及间歇性新能源大量接入电网,电能质量问题一直是近些年来供用电双方所关注的重点。深入了解不同非线性负荷的电能质量特性,进行非线性负荷接入电网的电能质量评估,可为电力公司对负荷的管理以及制定相应的治理措施提供依据。在典型非线性负荷的电能质量特性方面,本文主要研究了五类在电网中常见的典型非线性负荷,包括化工整流负荷、轧机、电弧炉、中频炉和电气化铁路牵引负荷。从负荷特性情况、主要电能质量问题及补偿治理方案三方面进行分析,给出了各类负荷电能质量指标的计算方法,以及五类负荷所产生的特征谐波含有率的建议取值。对于电气化铁路牵引负荷,针对机车速度对谐波含量的影响,将典型车型的速度与谐波含量间关系进行拟合,给出了拟合后的函数关系式。对于轧机负荷的补偿,综合考虑补偿效果、投资成本、无功变化情况以及负荷情况四个方面因素,给出相应的轧机谐波补偿和治理方案选取方法。在非线性负荷干扰性综合评估方面,借鉴对系统侧的电能质量综合评估方法对负荷的干扰性进行评估,先基于层次分析法(AHP)与DS证据理论求取各指标对电网影响程度的权重值,并针对其主观性强的缺点进行改进,淡化了算法中的人为主观性,同时使计算过程得到简化；再将指标权重结合灰色关联分析法给出非线性负荷与标准负荷间的关联度,以关联度的大小来表示负荷对于电网的干扰程度。
[Abstract]:With nonlinear load and intermittent new energy connected to power grid, power quality problem has been the focus of attention of both power supply and power supply in recent years. The power quality assessment of the nonlinear load connected to the power network can provide the basis for the power company to manage the load and formulate the corresponding treatment measures. In the aspect of power quality characteristic of typical nonlinear load, this paper mainly studies five kinds of typical nonlinear load, including chemical rectifier load, rolling mill, arc furnace, etc. The traction load of intermediate frequency furnace and electrified railway is analyzed from three aspects: load characteristic, main power quality problem and compensation treatment scheme, and the calculation method of various load power quality indexes is given. For the traction load of electrified railway, according to the influence of locomotive speed on harmonic content, the relationship between typical vehicle speed and harmonic content is fitted. The fitting function relation is given. Four factors, compensation effect, investment cost, reactive power change and load condition, are considered synthetically for the load compensation of rolling mill, and the corresponding selection method of harmonic compensation and treatment scheme for rolling mill is given. In the aspect of nonlinear load disturbance comprehensive evaluation, the power quality comprehensive evaluation method on the system side is used to evaluate the disturbance of load. First, based on AHP (Analytic hierarchy process) and DS evidence theory, the weight value of the influence degree of each index on the power network is calculated, and its subjective disadvantage is improved, the artificial subjectivity in the algorithm is desalinated, and the calculation process is simplified. Then the correlation degree between nonlinear load and standard load is given by combining index weight with grey correlation analysis. The magnitude of correlation degree is used to express the interference degree of load to power network.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM711

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