What does it mean for a governor to be isochronous?

An isochronous governor is one that maintains a constant speed of the generator regardless of changes in load. It achieves this by having a droop of 0%. In technical terms, droop is a percentage that indicates how much the speed (or frequency) of the generator falls as the load increases. A governor with 0% droop will not allow any frequency drop when the load changes, thus keeping the generator's speed constant.

This is essential in ensuring that power supply and demand remain balanced, particularly in systems where maintaining frequency is critical to stability. Isochronous governors are typically used in scenarios where precise control of system frequency is necessary, such as in auxiliary systems operating parallel to the main grid or in small isolated systems.

Understanding the role of droop is fundamental in differentiating governor types, and it helps to grasp how they interact within the power system to achieve consistency in operation.