一种具有频率变化适应性的并网逆变器改进型重复控制方法

发布时间：2018-01-05 00:34

本文关键词：一种具有频率变化适应性的并网逆变器改进型重复控制方法　出处：《电工技术学报》2014年06期 　论文类型：期刊论文

【摘要】：随着分布式发电系统的不断应用,并网逆变器的输出功率品质受到了大量的关注。重复控制技术由于具有优秀的稳态跟踪性能和极低的总谐波失真(THD),在逆变器系统中得到了广泛的应用。然而在分布式发电系统中,电网频率存在一定的波动,此时系统采样频率与电网频率的比值不能保持为整数,导致重复控制的谐振频率偏离了电网实际的基波与谐波频率。传统重复控制在这种系统中的性能将会显著的降低。本文提出了一种改进型重复控制方法,其采用了一个基于线性插值法的数字滤波器,而此数字滤波器能够逼近于由频率比值小数部分构成的延时环节,从而使重复控制的谐振频率与电网实际的基波及谐波频率相吻合。本文提出的方法,通过根据电网实际频率快速调整此数字滤波器参数的方式,使系统达到了理想重复控制应有的稳态跟踪性能和THD,从而实现了系统对电网频率变化的适应。最后,仿真与实验结果验证了该方法的有效性。
[Abstract]:With the continuous application of distributed generation system, the output power quality of grid connected inverter has attracted a lot of attention. The repetitive control technology because total harmonic distortion has good tracking performance and low (THD), has been widely used in inverter system. However, in the distributed generation system, the grid frequency has certain fluctuation at this time, not the ratio of system sampling frequency and the frequency of the grid to maintain the integer fundamental and harmonic frequency leads to the resonant frequency of repetitive control deviates from the actual power grid. The performance of traditional repetitive control in this system will be significantly reduced. This paper proposes an improved repetitive control method, which uses a digital filter based on linear interpolation method, the digital filter can approximate to link the ratio of frequency components of the fractional delay, so that the repetitive control of Xie Zhenpin The rate of fundamental and harmonic frequency and power actual coincide. The method proposed in the paper, through the rapid adjustment of the digital filter parameters according to the actual power frequency, allowing the system to achieve the ideal of repetitive control should be steady tracking performance and THD, so as to realize the adaptive system of power grid frequency variation. Finally, simulation and experimental results to verify the effectiveness of the method.

【作者单位】：浙江大学电气工程学院;
【分类号】：TM464
【正文快照】： 1引言随着近年来新能源的不断发展和利用,应用于新能源的分布式发电系统受到了广泛的关注和研究。而并网逆变器则是其中的一个重要组成部分。为了减小对电网的污染,并网逆变器必须提高其输出功率因数,减小其输出电流的总谐波失真(Total Harmonic Distortion,THD)。为此多种针

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