Optimisation-based algorithm for constructing first zone of distance protection for flexible power lines

• Published in: IET generation, transmission & distribution Vol. 14; no. 21; pp. 4666 - 4674
• Main Authors: Davydova, Nadezhda, Shchetinin, Dmitry, Hug, Gabriela
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 02.11.2020
• Subjects: conventional zone construction algorithms; distance protection; engineering experience; fault parameters; flexible power lines; grid model; nonlinear protection; optimal zone characteristic; optimisation; optimisation‐based algorithm; optimised settings; over‐voltage protection; power grids; power system simulation; power system stability; power transmission control; power transmission lines; power transmission protection; power transmission reliability; proposed zone construction algorithms; Research Article; separable internal faults; series compensation devices; zone coverage; power transmission lines; power system stability; distance protection; power system simulation; separable internal faults; flexible power lines; over-voltage protection; nonlinear protection; power transmission control; grid model; zone coverage; optimisation; proposed zone construction algorithms; conventional zone construction algorithms; power transmission protection; fault parameters; series compensation devices; power grids; optimal zone characteristic; engineering experience; optimised settings; optimisation-based algorithm; power transmission reliability
• ISSN: 1751-8687; 1751-8695
• DOI: 10.1049/iet-gtd.2019.1765

The conventional first zone characteristic of distance protection is constructed mainly based on engineering experience, which limits its coverage of internal faults. The zone coverage is also adversely affected by the installation of series compensation devices with over-voltage protection. Despite research efforts to overcome these problems, developing an algorithm for constructing an optimal first zone characteristic that encloses only all separable internal faults remains a challenging task. This study addresses this issue by presenting an optimisation-based algorithm for constructing an adaptive optimal first zone characteristic for power lines. The algorithm takes into account different locations of the compensation devices along the line, their non-linear protection, and the inaccuracies in measurements and considered grid model. The proposed and conventional zone construction algorithms are compared using a grid model in MATLAB Simulink. The results demonstrate that the proposed algorithm is robust to input parameters and thus able to construct an optimal zone characteristic for a specified range of grid operating points and fault parameters. Moreover, the first zone obtained by the proposed algorithm covers substantially more internal faults than the conventional zone with optimised settings.