How is voltage regulation stability tested under load?

• A. Run the generator at no load and rely on automatic regulation only.
• B. Increase ambient temperature and observe voltage drop.
• C. Apply load with a load bank and monitor AVR response and voltage changes.
• D. Temporarily disconnect the governor and observe voltage drift.

Answer: (C)

Voltage regulation stability under load is tested by applying a controlled load and watching how the automatic voltage regulator responds and how the terminal voltage settles. Using a load bank provides a repeatable way to introduce different load levels, then you observe the AVR’s reaction—how quickly it adjusts excitation to restore the set voltage—and check the voltage behavior during the change. A good test shows the transient response (speed, any overshoot or oscillations) and the steady-state voltage at the new load, confirming the system can hold voltage within spec as the load varies. This approach directly evaluates the regulator’s ability to maintain voltage under real operating conditions. In contrast, testing with no load doesn’t stress the regulation mechanism, changes in ambient temperature aren’t a controllable electrical test, and removing the governor would remove the control loop entirely, not assess how the AVR stabilizes voltage.