What monitors AC generator output to provide voltage regulation and control and to protect the generator and its electrical load?

The Generator Control Unit (GCU) is responsible for monitoring the AC generator's output to ensure proper voltage regulation and control. It continuously measures the voltage and current produced by the generator, adjusting the excitation system as needed to maintain the desired output voltage level. This regulation is crucial not only for stable performance but also for protecting both the generator and the connected electrical load from anomalies such as voltage surges or drops, which could lead to equipment damage or operational failures.

The GCU also plays an essential role in system diagnostics and performance monitoring, providing critical information that helps technicians identify issues and maintain the integrity of the electrical system. Its functions typically include overload protection, under/overvoltage protection, and maintaining synchronism with other power sources when needed.

While other options may involve aspects of generator operation, none fulfill the specific role of monitoring and regulating generator output as comprehensively as the GCU. Voltage regulators tend to focus more directly on maintaining the output voltage level rather than providing the broad control and monitoring capabilities of the GCU.