What is characterized by the ability of the system to withstand small changes without loss of synchronization?

The ability of a system to withstand small changes without losing synchronization is best characterized by steady state stability. This concept refers to the system's capability to maintain equilibrium under normal operating conditions, even when faced with minor disturbances such as load changes or slight fluctuations in system parameters.

Steady state stability is crucial for the reliable operation of power systems, ensuring that they can respond to routine variations without resulting in significant fluctuations that might lead to instability. When a power system is in a steady state stable condition, it means that any small perturbations will not cause the system to deviate significantly from its operating point, thereby preserving the synchronism of all generators connected to the grid.

In contrast, transient instability typically refers to the system's response to large disturbances or faults and its ability to remain stable immediately after such events. Primary stability involves the immediate behavior of the system right after a disturbance, while dynamic stability generally refers to how the system behaves over a longer time frame after a disturbance. Both transient and dynamic stabilities focus on different aspects and behaviors of the system under larger disruptions rather than small changes.