The Fault Direction Determination Method for the Near Area of the Outgoing Line of Photovoltaic Power Plant

Due to the large number of new energy access, the fault characteristics of the power grid have changed, resulting in the risk of incorrect operation of the directional components in the near area of the outgoing line of the photovoltaic power plant. To solve this problem, a fault direction discrimination principle based on the comparison of negative sequence current amplitude and positive sequence current amplitude is proposed in this paper. Based on the difference of the output sequence current amplitude between the photovoltaic power plant and the traditional synchronous generator during the fault period, the adjustment basis of the negative sequence current amplitude and the positive sequence current amplitude is given through theoretical analysis. Finally, a typical 110kV transmission system of photovoltaic power plant is established in PSCAD for verification. The simulation results show that the proposed protection criterion can judge the fault direction reliably and sensitively under different fault conditions.