What phenomenon occurs when there is a significant difference in voltage between two connected electrical systems?

The phenomenon that occurs when there is a significant difference in voltage between two connected electrical systems is synchronization failure. When two electrical systems with different voltage levels, frequency, or phase angle are connected, it can create instability and result in the systems being unable to synchronize with each other. This lack of synchronization can lead to damaging power flows and potentially result in equipment failures or power outages.

In the context of transmission systems and their operation, achieving synchronization is crucial for the stability and reliability of the electric grid. Systems must match in terms of frequency and phase to ensure a secure and efficient power transfer, and failure to achieve this can lead to operational problems.

While inrush current refers to the surge of current that occurs when electrical devices are first turned on, voltage sag denotes a temporary drop in voltage levels, and harmonic distortion refers to the presence of unwanted frequencies in the electricity supply, none of these directly address the issue of connecting systems with differing voltage levels or the specific consequences of synchronization failure.