改进的单相两点跌落电压检测新方法

Improved Single-Phase Two-Point Sag Voltage Detection Method

分析了目前常用的电压跌落单相瞬时电压dq变换检测法,在此基础上提出两种能实时准确获得电网电压幅值信息的算法:单相两点检测法和αβ-dq变换两点检测法。此两种方法计算简洁、实用性高,适用于DVR等电能质量补偿装置的跌落电压快速实时检测。理论分析了电网电压含有谐波和电网频率波动两种情况下,单相两点检测法的性能,并用PSCAD进行相应的仿真。理论分析和仿真结果均表明,在单相电压发生骤降的情况下,改进优化后的电压检测法能有效获取电网电压实时信息,更快速地检测出跌落电压,具有令人满意的动态响应速度和检测精度。

This paper analyzed the common single-phase instantaneous voltage dq transform method,and proposed two methods which can real-time and accurately obtain the grid voltage： single phase two-point method,andαβ-dq transform two-point method.The two methods are simple calculating,high practical,and suitable for rapid real-time voltage detection in power quality compensation device such as DVR.Confronting the two cases such as the harmonics and the power grid frequency fluctuation,the paper theoretically analyzed the performance of the singlephase two-point detection,then used the PSCAD to simulate the corresponding situation.The theoretical analysis and simulation results show that,in the situation of the single-phase voltage sag,the improved voltage detection method can effectively obtain the power grid voltage real-time information and detect the voltage sag more rapidly.The improved voltage detection method has satisfying dynamic response speed and detection accuracy.