What types of generators typically require a voltage schedule?

The need for a voltage schedule is primarily associated with larger generators, particularly individual units that are greater than 20 MVA. These generators have the capability to influence the stability and reliability of the electricity grid significantly due to their size. By requiring a voltage schedule, operators can ensure that these larger units operate within predefined voltage limits, helping to maintain the overall stability of the transmission system.

Voltage scheduling is crucial for larger units as they can affect voltage levels in their vicinity and across wider areas in the grid. The management of their output voltage can help avoid overvoltages or undervoltages, which can compromise grid stability and the performance of other equipment connected to the system. Smaller generators and backup generators typically do not have the same level of impact on grid voltage and, as such, have different operational requirements. This is why larger generators specifically are the focus when discussing the necessity for a voltage schedule.