Black-start Safety Analysis Of Dandong Grid

In recent years,introduction of new technology and equipment in the power system has improved the stability of power system,but also added a lot of unstable factors to power system.At the same time,blackout accident happens frequently as a result of natural disaster and human factor,causing huge loss of economy and society.While we enhance the power system stability,it is necessary to study black-start problem after blackout.In the event of an emergent power outage,we must take decisive measures to resume normal power supply,or delaying the recovery process may lead to accident expanding and more severe loss.Black-start refers to the process to restore power system after the system blackouts.To draft the safe black-start scheme is the effective means to ensure the system quickly recover after blackout.In this paper,combined with the actual situation of Dandong grid,choose a proper black-start power supply and the black-start path in the region.The key problems in the process of Dandong grid black-start,such as the generator self-excitation,transmission line overvoltage,and the auxiliary load start-up's impact to the voltage and current of the small restored system,has carried on the theoretical analysis and simulation study.Based on the electromagnetic transient software PSCAD/EMTDC,the article analyzes the excitation problem of Dandong power grid black-start scheme,the no-loaded transmission line charging overvoltage in three modes,and the auxiliary engine start-up problem in two modes.Analyze the simulation results to verify the feasibility of Dandong power grid black-start scheme.Compare the relative merits of all kinds of charging and start-up modes.The theories and simulation in this paper have an important reference value to the power system black-start scheme drafting,and supplement the power system security defense system and the national emergency management system.