采用小波变换和同相位补偿的不间断动态电压恢复器

Uninterrupted Dynamic Voltage Restorer (UDVR) Using Wavelet Transform and In-phase Compensation

为消除瞬时电压扰动,提高电压质量,在介绍了不间断运行动态电压恢复器(UDVR)的工作原理、拓扑结构、工作模式及电压补偿策略后,提出了应用小波变换来检测动态电压恢复器中电压畸变特征量的方法,该算法对电源电压发生跌落、骤升、三相不平衡、伴随谐波等运行工况实现了畸变分量幅值和相位的无延时检测。以最新的三单相电压源型逆变电路独立补偿主电路取代传统的三相同时补偿,对UDVR在不同工况下的动态电压补偿特性进行了仿真实验研究。结果表明采用小波变换的UDVR具有较好的实时性和补偿灵活度,可以有效地抑制电网中各种电压暂态扰动,是解决电压型电能质量问题的有效手段,能满足敏感电力负荷在复杂电压暂态环境下的不间断运行。

The work principle,topologic structure,operation pattern and voltage compensation strategy of an uninterrupted dynamic voltage restorer（UDVR） are introduced in detail,respectively.The wavelet transform is used detecting distortion voltage components of UDVR.The proposed detecting method based wavelet transform algorithm can detect the magnitude and phase angle of the distortion components of the source voltage instantaneously under sag,swell,unbalanced and harmonics conditions.The traditional main circuit of three-phase simultaneous compensation is improved by replacing with three independent single-phase compensations based on voltage source inverter circuit.The dynamic compensation characteristics of UDVR are applied to voltage transient disturbance analysis under various run conditions.Simulation results prove that the proposed method is correct and has better real-time and compensation flexibility.The UDVR can mitigate many kinds of voltage transient disturbances in power system.It is an effective means to solve power quality problems and can satisfy the uninterrupted run of sensitive loads under various voltage transient conditions.