【作者】 康健；

【导师】 张培铭； 邵振国；

【作者基本信息】 福州大学 ， 电机与电器， 2010， 博士

【摘要】 随着电力系统冲击性负荷的急剧增加，某些电网的电压波动、闪变达到了非常严重的程度，进行闪变传播的相关研究，对于闪变限值的计算以及闪变污染源的定位、治理都具有重要的意义。鉴于闪变检测是闪变分析的基础，首先提出一种改进的闪变值检测算法。该算法可解决数字式闪变值检测中闪变频率较大时测量误差增大的问题。针对闪变在电网的传播问题，提出了基于动态相量法的电网闪变传播系数的计算方法。现有方法采用稳态电路或者稳态潮流的计算方法来描述闪变的传播规律，缺乏具有针对性的闪变传播规律的描述方法。本文首先应用动态相量法建立面向闪变研究的电力系统基本元件的动态相量模型，然后依据动态相量域的基尔霍夫电压电流定律建立起面向闪变研究的电网模型，并最终推导出简化的闪变传播规律。将上述电压闪变传播规律与已有的闪变传播计算方法相比较，分析表明：已有闪变传播计算方法在电网中各阻抗参数的相角接近的前提下具有较高精度，而本文提出的方法具有更一般性。为研究电动机负荷对闪变传播的影响，提出了面向闪变研究的三相感应电动机的动态相量模型。该模型的理论基础为三相感应电动机的电压方程、电磁转矩方程和基本运动方程。利用该模型推导了波动电源电压情况下，电动机电流的间谐波频率分量和转子机械角速度变动量；并以此为基础，深入研究了电动机负荷对闪变传播影响的频率特性。研究结果表明：电网中存在感应电动机的情况下，闪变传播具有明显的频率特性，此时的闪变传播系数与电压波动中的各闪变频率分量的组成有关；在绝大部分闪变频率下，感应电动机负荷对闪变具有抑制作用。为了分析电弧炉运行造成电压闪变的机理，提出了一种新的电弧炉动态模型。该模型是一种由多值伏安特性描述的电弧炉动态模型，可以体现弧长变化对伏安特性曲线的实际影响。最后，在此基础上深入进行了电弧炉闪变的影响因素分析。更多还原

【Abstract】 With the rapidly increase of impulse loads in power system, the voltagefluctuations and flicker of some areas have reached a very serious level. It ismeaningful for calculation of flicker limit,location and governance of flickersource to study flicker propagation.An improved detection algorithm of flicker value was proposed firstly asflicker detection was the basis of flicker analysis. The algorithm can solve theproblem that the measurement errors increased with higher flicker frequencies.A calculation method of flicker transfer factors based on dynamic phasorsmethod was proposed to study flicker transfer in power system. The existingmethods adopted calculation methods of steady circuit or steady power flow todescribe flicker propagation rules, lacking special study method of flickerpropagation rule.The dynamic phasor models of the general components of powersystem which are suitable in flicker study were established by dynamic phasorsmethod. With the Kirchhoff’s voltage and current law in dynamic phasor domain，the dynamic phasor models of the electric power grids were established and asimplified flicker transfer regularity were derived finally. The above flickertransfer regularity was compared with the current flicker transfer calculationmethods. The analysis shows that the current flicker transfer calculation methodsare more accurate only when the impedance angle of various impedances of powersystem are close and the method proposed in this paper is more generic.To study the effect of induction motor on flicker transfer,the dynamic phasemodel of three-phase induction motor applicable for flicker study was established.The basis of the model was the voltage equations, electromagnetic torque equationsand basic equations of motion. In the case of fluctuant source voltage, the modelrealized the quantitative calculation of stator current inter-harmonics componentsand variation quantity of rotor mechanical angular velocity of induction motors. Onthe basis of that, the frequency characteristics of flicker transfer under motor loadswere deeply studied. The study shows that when induction motors exist in powersystem, the flicker transfer from the source to the motor shows obvious frequencycharacteristics and the flicker transfer coefficients are concerned with the distribution of various flicker frequency components. The analysis also shows thatfor most flicker frequencies the induction motors help attenuation of flicker.To study the mechanism of voltage flicker caused by arc furnace operation, annew arc furnace model was proposed. The new model was dynamic model of arcfurnace described by multiple value volt-ampere characteristic curves, reflectingthe actual influence of arc length variation on volt-ampere characteristic curves. Onthe basis of that, the influencing factors of arc furnace flicker were furtheranalyzed.更多还原