中文摘要：

动态电压恢复器（DVR）是有效解决电压跌落问题的一种电力电子装置。为获得精确的电压补偿信号,快速准确的电压跌落检测是DVR控制的重要前提。分析了现有电压跌落检测方法,并因电网谐波畸变不同按电压跌落深度、跌落相位、相位跳变、谐波等综合因素,提出了无谐波电网以电压dq分量一阶导数之和检测基波电压幅值的方法,对含谐波电网提出半周期实时计算dq分量平均值的方法,其取样窗口宽度固定不变,采样时刻自动变化,实时计算电网电压基波幅值。通过不同条件下的仿真和物理实验,对所提方法进行了验证。在不同电压跌落深度、跌落相位、相位跳变、谐波畸变等综合情况下,基波幅值检测波动小,检测时间短,精确稳定,易于实现,无复杂运算;此方法不需要锁相环、低通滤波器、查表计算,实时性强;对于含谐波畸变电网,可满足快速检测要求,具有较好的动态响应。

英文摘要：

Dynamic voltage restorer, as a power electronic device, is effective to solve the problem of the voltage sag. Rapid and accurate voltage sag detection is an important prerequisite for DVR control, depending on which, accurate voltage compensation signal can be obtained. In this paper, the existing voltage sag detection methods have been introduced and a new method has been proposed under various conditions considering all possible cases such as different amounts of voltage sag depth, voltage sag phase, phase jump and harmonic distortion. In the proposed method considering non-harmonic cases, by solving the derivation of d-q components, the fundamental voltage amplitude can be calculated. Meanwhile, in harmonic cases, it can also be obtained by solving the average value of d-q components in a fixed sampling window width automatically changed. According to simulation and experimental results under various conditions, the proposed method is verified. Under various voltage sag depth, voltage phase, phase jump and harmonic distortion, advantages of the proposed method are as follow： small ripple of the calculated fundamental voltage amplitude, short detection time, precise and stable detection, ease of implementation and computation, no need of phased locked loop, lookup table and low-pass filter, strong real-time performance. Finally, for a distorted power grid, the method can meet the requirements of fast detection and receive a better dynamic response.