适用于双馈风机的并网电压波动与闪变检测系统的研究

Research on Grid-Connected Voltage Fluctuation and Flicker Detection System Suitable for Doubly-Fed Fan

风电因电能质量问题影响使其发展受到制约,电压波动及闪变是其中之一。使用目前的闪变仪对风电机组并网引起电压闪变进行检测,发现在检测低频段波动引起的闪变时误差较大,而这也是风电并网产生闪变的主要频段。因此,如何使低频段检测误差减小是该文研究的意义。根据IEC标准,在Matlab平台建立数字闪变检测系统仿真模型,并利用双线性方法求得系统的参数。针对上述情况,分析其误差产生的原因,通过对检测的瞬时闪变视感度S(t)引入参数校正以减小低频检测误差,使其满足风电并网闪变值检测的要求。最后将修正系数后的检测系统运用在一个双馈风力发电系统实例中,证明该风电场满足我国电压闪变值要求。

The development of wind power is constrained by its power quality, and the influence of voltage fluctuation and flicker is one of factors which affect the power quality. At present, the flicker meter is often used to detect the voltage flicker which is caused when wind turbines are connected to the power grid. It is found the error is bigger when the flicker caused by the low frequency fluctuation is detected, and this is also the main frequency band where flickers occur when wind turbines are connected to the power grid. Therefore, this paper aims at how to reduce the low frequency band detection error.According to the IEC standard, the digital flicker detection system simulation model is built in the Matlab platform, using the bi-linear method to obtain the parameters of the system.According to the above situation, the paper analyzes the causes of the error, and based on the instantaneous flicker visual sensitivity in detection of S( t) correction parameters are introduced to reduce the low frequency error so that the require-ments for the wind power grid flicker value detection are met.Finally, the detection system with coefficients corrected is applied in the actual case of the doubly-fed wind power generation system, and it has proved that the wind farm satisfies the requirement of the voltage flicker value in our country.