Improvement of Power System Stability by Changes in the Network

Changes in the network such as connecting shunt- resistor brakes, disconnecting generators or load, and inserting series capacitors, each rapidly accomplished under suitable control, can counteract other sudden, undesired changes in the network (short circuits or accidental loss of loads or generators) which threaten the stability of interties. The countermeasures taken should match the disturbance with respect to location, amount, duration, and dependence on angular difference. Such measures can improve stability of interties more economically than can construction of additional circuits.