基于阻抗归一化趋势判别的谐波发射水平估计  

Assessing Harmonic Emission Level Based on the Impedance Gathering Trend Discrimination

作　　者：惠锦[1] 杨洪耕[1] 叶茂清[2] 

机构地区：[1]四川大学电气信息学院,四川省成都市610065 [2]四川省电力试验研究院,四川省成都市610072

出　　处：《中国电机工程学报》2011年第10期73-80,共8页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51077095)~~

摘　　要：首先分析利用谐波电压电流自然波动量之比来计算系统谐波阻抗及谐波发射水平的要点及关键问题,理论上分析并证明基于波动量比值实部符号判别的阻抗计算方法(简称"符号判别法")是不完备且有较大局限性的。其样本筛选过程只能排除一部分相角不正确的结果,却剔除了一部分相对误差较小的结果,同时误保留了一些实部为正但误差较大的结果。从两侧谐波电流波动的随机特性出发,提出一种基于阻抗归一化趋势判别的谐波发射水平估计方法,通过判别阻抗趋势图中的盲区和聚合区,筛选出更有价值的阻抗计算样本点。仿真及实际工程算例验证该方法的准确性和有效性,同时说明了符号判别法的局限性。This paper first analyzes the essentials and crucial problems in measuring harmonic impedance by calculating the ratio of natural harmonic voltage fluctuation to harmonic current fluctuation. Theoretical analysis shows that the traditional approach which is based on the sign judgment of the real part of the ratio of two fluctuations （＂symbolic discriminated method＂） is incomplete and has great limitations, it only excludes those impedance samples whose phase angles are theoretically incorrect; at the same time, some valuable results with small relative errors are excluded and some inaccurate results with positive resistances are kept. Starting from the random characteristic of harmonic fluctuation, this paper presents a novel approach for harmonic impedance and emission calculation, it selects more valuable impedance samples from all the measured ones at the point of common coupling （PCC） by discriminating the blind zone and aggregation zone from the impedance gathering trend figure. Simulation and field tests show that the proposed approach is accurate and effective, and has applications; meanwhile the strong prospects in practical limitations of ＂symbolic discriminated method＂ are illustrated .

关 键 词：电能质量 公共连接点 谐波发射水平 谐波阻抗 非干预式 

分 类 号：TM72[电气工程—电力系统及自动化]