It was found that hidden failures in protection schemes caused the disconnection of power system elements in an incorrect and undesirable manner contributing to the disturbance degradation.

The disconnection from power network of power plants under emergency conditions may cause serious frequency drop and then large area outage, even power network collapse.

House load operation of gas turbine is described as an operation with station-service power under the condition of disconnection to main power grid, which can make a power plant operate safely.