Zone 3 Relay Blocking Scheme to Prevent Cascaded Events

Defense systems are needed to prevent catastrophic failures of a power grid due to cascaded events. Cascaded events can be attributed to improper operations of protective relays. The most challenging problem for the design and implementation of a defense system is the performance in accuracy and speed in a real time environment. Protective devices are normally designed to operate fast in order to isolate the fault（s）. This paper proposes a new methodology to distinguish line overloads from actual faults for distance relays. In order to distinguish between line flow transfers from a line outage and an actual fault, the line outage distribution factor （LQDF） and generation shift factor （GSF） based power flow estimation method, and a secure peer to peer （P2P） communication structure are adopted. Computer simulations of cascaded events for a 6-bus system and the Korean power grid have been performed to establish the feasibility of the proposed scheme.

Generating Baikal-GVD high energy cascade-like neutrino events with a GEANT4-based simulation toolkit

Using the GEANT4 and Cosmic Ray Monte Carlo(CRMC)software packages,we developed a new simulation toolkit for astrophysical neutrino telescopes.By configuring the Baikal-GVD detector and comparing the vertex position and direction of incident particles,as well as the channel-by-channel signals,to the events detected by Baikal-GVD,we successfully generated 13 high-energy cascade neutrino events with the toolkit.Our analysis revealed a systematic offset between the reconstructed shower position and the true interaction position,with a distance close to the scale of the shower maximum of−0.54±1.29 m.We achieved a good linear relationship between the photoelectron number of neutrino events obtained by simulation and the real data measured by Baikal-GVD.The simulation toolkit could serve as a reliable basis for studying the performance of astrophysical neutrino telescopes.

Nonlinear Energy Cascading in Turbulence during the Internal Reconnection Event at the Sino-United Spherical Tokamak

The characteristics of the energy transfer and nonlinear coupling among edge electromagnetic turbulence in thermal quench sub-period of the internal reconnection event （IRE） are studied at the sino-united spherical tokamak device using multiple Langmuir and magnetic probe arrays. The wavelet bispectral analysis and the modified Kim method are applied to investigate linear growth/damping and nonlinear energy transfer rates, along with multi-field turbulence interactions. The results show a multi-field nonlinear energy transfer from electrostatic to magnetic turbulence that results in two-mode coupling in magnetic turbulence, which may play a crucial role to trigger the IRE.