What is the stability of parallel operation for diesel generator sets?

The stability of parallel operation refers to the ability of the power generation unit to maintain synchronous operation when subjected to disturbances. Just like in industrial large-scale power systems, the parallel operation of diesel generating sets and their electrical equipment, connected through distribution equipment and cables, form a complete power system. This system also faces issues of static and dynamic stability. Static stability pertains to the system's ability to return to a stable operating condition before the disturbance (such as minor changes in generator load or low-force-torque disturbances from diesel engines), while dynamic stability concerns the ability of the generating set to maintain synchronous operation after a severe and sudden disturbance. For instance, events like power grid short circuits, startup of high-power asynchronous motors, sudden tripping of a parallel generating set, or high-frequency differences or large error angles during paralleling, can cause significant disturbances to the power station. After such disturbances, the generating set should continue to operate synchronously after a certain amount of oscillation, which is referred to as dynamic stability.