Governor control study at the time of a black start

The power system of Kyushu Electric Power Company Inc. (KEPCO), whose size is about 19 GW, belongs to the Western Japan interconnected power system of 110 GW. Its grid system is made up of 500 and 220 kV transmission lines in a looped configuration. When the KEPCO power system falls into a blackout, it will be restored from a small-scale power system to the extent that it cannot be compared with its grid size (110 GW) usually operated. First some prespecified hydro-generators will be started and interconnected with each other, and then a load will be added step by step to configure a small-scale power system. The governor type of those hydro generators to be used for a black start will be a mixture of PID governors and PD governors (proportional control with transient droop). This work reports a frequency stability study for such a small-scale power system with hydro generators at the time of a black start.