AMPS Technical Committee One of the more important aspects of generating set performance is the ability to accept step loads. The AMPS Technical Committee Task Group, led by Chris Whitworth of Newage, has for some time been studying the effect of load pick-up and the resulting transient effect on voltage and frequency. The ac generator is the first to see the initial change of current when a new load or a change in load is instantly applied at the generating set output terminals. The results of this sudden change are not always expected.
Many criteria can have an effect upon the result.
The Task Group is therefore investigating published performance standards to establish whether they include sufficient information regarding transient behavior for assessment to be made by the manufacturer and customer. Some of the existing standards define transient performance capabilities in different ways. These are VR0 to VR3 and nominate categories that identify certain capabilities within each of the grades. Part 16 does not specify grades of performance, but in section 48 does cover voltage deviation and recovery time. It should be noted that all of these standards are based upon performance when the electrical machine under test is driven at substantially constant speed.