Pei Liu

TL;DR: In this paper, the possibility of nonoperation of second-harmonic restraint differential protection in the case of internal faults of power transformers was studied and modified schemes for improved operation for internal faults were presented.

TL;DR: In this article, a fast unblocking scheme for distance protection to identify symmetrical faults occurring during power swings has been proposed, where the change rate of three-phase active power and reactive power being the cosine function and the sine function with respect to the phase difference between the two power systems during power swing has been demonstrated.

TL;DR: In this paper, a comprehensive scheme to study transmission vulnerability based on the fault chain theory of security science is proposed, where the cascading failure process and its generic features are described according to a fault chain and a new vulnerability assessment index is presented to identify critical lines and sections contributing to failure extension and system instability.

TL;DR: In this article, an improved waveform correlation coefficient between the first half-cycle and the latter-half-cycle of the above measurand is used to distinguish between inrush and internal faults in the transformer.

TL;DR: In this article, a dual-window transient energy ratio (ER) based on mode current was proposed to implement the adaptive autoreclosure of transmission lines, which is more flexible and the relative factors of the structure element can be regulated according to the desirable effects.