Pilot Protection Method of Flexible DC Grid Based on Linear Regression
Shu Hongchun1,2, Dai Yue1,2, An Na1,2, Tang Yutao1, Bo Zhiqian1
1. State Key Laboratory of Collaborative Innovation Center for Smart Grid Fault Detection Protection and Control Jointly Kunming University of Science and Technology Kunming 650500 China; 2. Faculty of Mechanical and Electrical Engineering Kunming University of Science and Technology Kunming 650500 China
Abstract：When a fault occurs in a flexible DC grid line, the line protection device needs to quickly and reliably remove the faulty line to ensure that the healthy line can operate normally to improve the safety and reliability of the transmission system. In this paper, a linear regression method for fast pilot protection of flexible DC grid is proposed. Firstly, the physical boundary formed by the modular multilevel converter (MMC) equivalent impedance and the smoothing reactor is analyzed for the attenuation of the high frequency components, and secondly, the current loop and the current flow of the healthy line are analyzed for the single-pole and double-pole faults of the transmission line, and then the regression coefficient of the short-time window current is used for the identification of faults inside and outside the area and the selection of the faulted pole according to the energy of the voltage mutation of the transmission line as the protection activation criterion. A simulation model of the flexible DC network is built on PSCAD to verify the protection scheme. The simulation results show that the protection method can reliably and accurately screen faults with good quick action, and has good transition resistance and applicability.
束洪春, 代月, 安娜, 唐玉涛, 薄志谦. 基于线性回归的柔性直流电网纵联保护方法[J]. 电工技术学报, 2022, 37(13): 3213-3226.
Shu Hongchun, Dai Yue, An Na, Tang Yutao, Bo Zhiqian. Pilot Protection Method of Flexible DC Grid Based on Linear Regression. Transactions of China Electrotechnical Society, 2022, 37(13): 3213-3226.
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2022, Vol. 37 
