A Study Of Scheme On Low-frequency Load Shedding In Tai’an Power Grid

As the last defense line of the three lines of ensuring the power grid safety operation, low-frequency load shedding is a special means of ensuring the stability by cutting off some loads after major accidents. When the system frequency is falling, it’s very important to cut off loads to keep the power supply and load rebalance in order to prevent power system collapse from frequency greatly increasing. Meanwhile, it also makes big difference to ensure important loads power supply and prevent power system collapse and large area blackout from extreme cases of small probability. Low-frequency load shedding is widely applied and studied in power system.In this thesis, the research case is Tai’an grid which is a receiving power network. The influence factors of low-frequency load shedding operating reliably and sufficiently are deeply studied. The adaptability of low-frequency load shedding in Tai’an grid is also a part of study. Based on the scheme of low-frequency load shedding in the whole power grid, the scheme of regional power grid is adjusted appropriately. In consideration of the small thermal power low-frequency disconnection fixed value’s relationship, the scheme of "basic round+special round +localized special round" on low-frequency load shedding in Tai’an power grid is established. It gives reference to set up the last defense line of ensuring the power grid safety and reliability, prevents power system large area blackout and economic loss from partial failure. The ultimate goal is to ensure the Tai’an power grid security and the power supply reliability.