Power management in disasters: Application of loadshedding and wind turbine controller

Electric infrastructure is vulnerable to damage during disasters and the downstream microgrid may be left without electricity for a long time. Even networks with distributed generators (DG) will fail due to immediate frequency fluctuations that are the results of mismatch between electrical demand and generation. This paper studies the campus of The University of British Columbia´s electrical network, and analyses its future expansion needs in terms of expanded local generation to meet the demand growth while reducing greenhouse emissions. In particular, local biomass CHP and wind generation are standard while working together with the main power grid supply. The paper introduces a load and generation management method for the campus during and after disasters to mitigate campus-wide power outages. The methodology is a combination of two-stage loadshedding and wind turbine regulation to reduce the islanding duration time while maintaining frequency at normal level. Immediately after a power outage, the wind turbine maintains the frequency close to normal until primary loadshedding completes and a few seconds later the island is reconnected to the grid. If multiple synchronization and reconnection attempts are unsuccessful, the second stage of loadshedding occurs at the same time that the wind turbine controller disconnects. Once the wind turbine returns to its initial operation, loads that were disconnected in the second phase are restored and the microgrid continues its operation with the least number of loads disconnected. A load priority scheme is considered to exist for the load shedding and restoration scheme.