The bulk power system is the large-scale network that generates, transmits, and moves electricity across regions and interconnections. It includes major transmission lines, substations, generation resources, and control equipment that keep the grid synchronized and stable. It is different from local distribution systems that deliver power to homes and small businesses.
In cyber security, the bulk power system matters because disruption at a few critical nodes can ripple across a wide area, causing outages, instability, or recovery delays. Attackers may target its monitoring, control, or protection systems to hide faults, alter operations, or amplify physical damage. Defenders treat it as a cyber-physical environment: they use segmentation, strong access control, monitoring, and risk-based physical protection to reduce the chance that one compromised site can affect the wider grid.