1.School of Electrical Engineering, Xinjiang University, Urumqi 830047, China;2.College of Electrical Engineering and Automation, Fuzhou University, Fuzhou 350116, China;3.School of Automation, Nanjing Institute of Technology, Nanjing 211167, China
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.
This work is supported by National Natural Science Foundation of China (No. 51667021) and Regional Collaborative Innovation Project from Xinjiang Uygur Autonomous Region of China (Science and Technology Aids Program) (No. 2018E02072).
|||ZHANG Jianxin, XIE Lirong, DU Liwei, et al. Half-cycle Detection for Fundamental-frequency Voltage Considering Decaying DC Component[J]. Automation of Electric Power Systems,2021,45(14):158-164. DOI:10.7500/AEPS20200925009|