计及衰减直流分量的基频电压半周期检测

衰减直流(DDC)分量、高次谐波等干扰信号的存在,使得对电网畸变信号中基频分量的幅值、相位检测存在一定误差,其中DDC分量的时间常数通常超过45 ms,持续时间较长.为此,文中首先针对畸变信号中DDC分量提出一种半周期四点采样检测算法,缩短了DDC分量的检测响应时间.其次,针对同时含有DDC分量与高次谐波的畸变信号,提...

Half-cycle Detection for Fundamental-frequency Voltage Considering Decaying DC Component

The existence of interference signals, such as decaying direct current (DDC) components and high-order harmonics, makes certain errors in detecting the amplitudes and phases of fundamental frequency component in the distortion signals of the power grid. The time constant of the DDC component usually exceeds 45 ms, and its duration is long. To solve this problem, this paper proposes a half-cycle four-point sampling detection algorithm for DDC components in distorted signals. The proposed algorithm can greatly shorten the detection response time for the DDC component. For the distorted signals that contain both DDC components and high-order harmonics, the above DDC component detection algorithm is combined with the high-order harmonic detection algorithm in the dq coordinate system after the half-cycle integration of the distorted signals. The influence of interference signal can be filtered out at the same time in a half-cycle of the power frequency, and the fundamental-frequency component in the distorted signal can be detected accurately. Finally, a semi-physical real-time simulation model in MATLAB/Simulink is built to verify the effectiveness of the proposed algorithm in terms of detection accuracy and response time.