Single-end Electrical Quantity Protection Scheme for MTDC Power Grid Based on Specific Frequency Band Transient Energy Ratio on Both Sides of Current-limiting Reactor
Flexible DC transmission technology is conducive to the future integration of a large amount of distributed energy in power grid,and the construction of fast and reliable protection schemes is the key to flexible DC technology development.According to the equivalent model of DC grid,this paper proposes a single-end electrical quantity-based fault area identification method based on the difference of transient energy ratio in the specific frequency band of voltage on both sides of current-limiting reactor.This method calculates the voltage ratio on both sides of the current-limiting reactor with Berilong equivalent model,extracts the voltage in the specific frequency band on both sides of the current-limiting reactor through generalized S transform,and realizes fault pole selection according to the difference of voltage amplitude between positive and negative current-limiting reactors during faults.Finally,a simulation model is built on PSCAD/EMTDC platform.The analysis shows that there is obvious difference when faults occur inside and outside the area,with strong resistance to transition resistance and noise interference.
multi terminal flexible DC power gridtransient energy ratiosingle ended electrical quantity protectionline protectionfault pole selection
NETL
NSTL
万方数据
维普
