电容式电压互感器电路参数对电网谐波电压测量的影响

发布时间：2018-05-13 05:13

本文选题：电容式电压互感器 + 级联分级分析　；参考：《中国电机工程学报》2014年28期

【摘要】：针对66 kV以上等级电网大多采用电容式电压互感器(capacitor voltage transformer,CVT)、其谐波传变特性定量规律不明、不宜进行谐波电压测量的现状,论证谐波条件下的CVT可等效为一线性电路,并以此为基础提出级联分级分析方法。结合实际参数对每级谐波传变特性进行分析,获得CVT电路参数对其谐波传变特性的定量影响规律,即明确利用CVT测量谐波电压的影响因素。仿真结果表明:中间变压器一次侧线圈的等效杂散电容将导致CVT幅频特性在1 kHz之后的某频率点发生放大;阻尼器参数影响50 Hz以上频段的频率特性变化率;负荷在1~10倍额定负荷范围变化以及中间变压器励磁阻抗在0.1~1倍额定参数范围变化时对CVT频率特性的影响可忽略。所得结论对CVT产品设计及利用其测量谐波电压具有借鉴意义。
[Abstract]:In view of the fact that capacitors voltage transformers are mostly used in 66 kV or above power networks, the quantitative law of harmonic transmission characteristics is unknown and it is not suitable to measure harmonic voltage. It is proved that the CVT under harmonic condition can be equivalent to a linear circuit. On this basis, a cascade hierarchical analysis method is proposed. Based on the analysis of the harmonic transmission characteristics of each order based on the actual parameters, the quantitative influence of CVT circuit parameters on the harmonic transmission characteristics is obtained, that is, the influence factors of measuring harmonic voltage by CVT. The simulation results show that the equivalent stray capacitance of the primary side coil of the intermediate transformer will result in the amplification of the CVT amplitude-frequency characteristic at a frequency point after 1 kHz, and the damper parameters will affect the frequency characteristic change rate of the frequency band above 50 Hz. The influence of load range of 10 times rated load on the frequency characteristics of CVT can be neglected when the excitation impedance of intermediate transformer changes in the range of 0.1 times rated parameters. The conclusions can be used for reference in the design of CVT products and the measurement of harmonic voltage.
【作者单位】：中国电力科学研究院;
【基金】：国家电网公司科技项目(SGTGY JSFW(2012)346)~~
【分类号】：TM451.2

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