Simulation and research on reducing voltage sags for important users during a special period

Some important power consumers have many voltage-sensitive loads and require high voltage quality especially in a special period. From the perspective of electricity utility, power supply model for a important customer is established with EMTDC/PSCAD. The impact of faults with different locations, different types and different duration on the voltage of customer is simulated. With the simulation results, the vulnerability of the power grid could be analyzed. Then the voltage sag for important customers could be avoid with some solutions, such as optimizing operation modes, using automatic voltage control system and arranging patrol reasonably by classifying equipments. Thus the probability of voltage sags could be decreased and the supply reliability could be improved in a short time for important users during a special period.