Which characteristic is essential for an isochronous governor?

The essential characteristic of an isochronous governor is its ability to maintain a constant frequency. This type of governor is designed to control the speed of a generator or turbine to remain constant despite variations in load. By controlling the output to match the load demand, the isochronous governor ensures that the generator frequency does not fluctuate, thus providing stability to the grid.

A key aspect of this function is its role in balancing generation and load in real time, which is crucial for maintaining the integrity and reliability of the electric power system. Unlike governors with a droop characteristic, which allow for some frequency variation proportional to load changes, the isochronous governor is specifically designed to operate without any allowed frequency droop, keeping the system frequency steady at a predetermined set point.

In contrast, a droop setting above 0% is actually a characteristic of governors that are designed to let frequency vary with load changes, making them unsuitable for the constant frequency requirements of isochronous operation. Operating during outages and enhancing system efficiency are important considerations in power system operation but do not specifically define the fundamental characteristic of an isochronous governor.