动态电压恢复器仿真与应用研究

发布时间：2018-09-09 16:33

【摘要】：随着电力电子技术的快速发展,电网中的敏感负荷日益增多,电力用户对电能质量的要求也越来越高。电能质量的保障是电网安全经济生产的前提,而电压暂降则是电网中频发的电能质量问题,波及范围广,危害程度高。目前,动态电压恢复器是抑制电压暂降问题的最有效的手段之一。首先,本文根据动态电压恢复器的工作原理,对动态电压恢复器拓扑结构进行了研究。其中,主要介绍了动态电压恢复器的几种典型拓扑,并分析不同类型的拓扑的特点及应用场合。在此基础上,对动态动态电压恢复器进行数学描述,建立相应的数学模型,从而得到动态电压恢复器的等效传递函数。其次,在电压检测方面,采用基于求导法的单相αβ-dq派克变换电压幅值和相角的检测方法,这种算法适用于单相电压的检测,计算量较小。在正负零序电压的分离方面,基于双向旋转的派克变换对正负序分离进行了分离,对于零序分离采用了三相叠加法。在锁相技术方面,分别对开环锁相和闭环锁相技术原理进行了分析。然后,对于动态电压恢复器的控制回路,采用比例谐振控制器控制下的复合控制策略,通过该控制策略的频域特性曲线,分析了该控制策略的优点。同时,对比例谐振控制器进行了改进,使其选频特性更加灵活,从而具有谐波补偿功能。最后,通过MATLAB/Simulink建模仿真,在复合控制策略的基础上,分别对电网电压跌落、相位移动、谐波干扰等的补偿问题进行了模拟实验,验证了该控制策略的合理性。与此同时,结合实际工程的DVR应用现状,说明DVR在实际抑制电压暂降问题的实用型和经济性。
[Abstract]:With the rapid development of power electronics technology, the sensitive load in power grid is increasing day by day. The guarantee of power quality is the premise of safe and economical production of power grid, and voltage sag is a frequent power quality problem in the power network, which has a wide range of spread and high degree of harm. At present, dynamic voltage restorer is one of the most effective methods to restrain voltage sag. Firstly, according to the principle of dynamic voltage restorer, the topology of dynamic voltage restorer is studied. Among them, several typical topologies of dynamic voltage restorer are introduced, and the characteristics and applications of different types of topologies are analyzed. On this basis, the mathematical description of the dynamic voltage restorer is carried out, and the corresponding mathematical model is established, and the equivalent transfer function of the dynamic voltage restorer is obtained. Secondly, in the aspect of voltage detection, the single-phase 伪尾 -dq Parker transform voltage amplitude and phase angle detection method based on the derivation method is adopted. This algorithm is suitable for the detection of single-phase voltage, and the calculation is relatively small. For the separation of positive and negative zero-sequence voltages, the positive-negative sequence separation is separated based on the bidirectional rotation Pike transform, and the three-phase superposition method is used for the zero-sequence separation. In the aspect of phase locking technology, the principle of open loop phase locking and closed loop phase locking are analyzed respectively. Then, for the control loop of dynamic voltage restorer, the compound control strategy under the control of proportional resonance controller is adopted, and the advantages of the control strategy are analyzed through the frequency domain characteristic curve of the control strategy. At the same time, the proportional resonance controller is improved to make its frequency selection more flexible, so it has harmonic compensation function. Finally, through MATLAB/Simulink modeling and simulation, based on the compound control strategy, the simulation experiments of voltage drop, phase shift and harmonic interference compensation are carried out respectively, and the rationality of the control strategy is verified. At the same time, combined with the application status of DVR in practical engineering, the practical and economical application of DVR in restraining voltage sag is demonstrated.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM714.2;TM761

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