2006-12-21 05:43:04 · 5 answers · asked by Sky Guy 3 in Science & Mathematics ➔ Engineering
1.Suppose two generators are started in parallel, and generator rating are different , then frequency synchronization is a vital factor before transmission of supply , otherwise it would go out of step and may get tripped of.
http://adsabs.harvard.edu/abs/1987MiJo...30..331S
http://216.239.59.104/search?q=cache:sN3HWCHPnngJ:www.apcmedia.com/salestools/TDOY-5UQVC7_R1_EN.pdf+frequency+synchronization+of+generators&hl=en&ct=clnk&cd=4
(Generator Synchronization Synchronization is essential for running generators on a parallel bus with other generators or the utility. The generator must be synchronized to the bus voltage reference before the paralleling switchgear will close it onto the bus. This is accomplished using a synchronizer unit, which drives the generator’s governor to control its engine speed and output voltage frequency. A generator synchronizer is also used with all closed transition transfer switches. The synchronizer will sync the generator when a utility reference ispresented to the line side of the transfer switch. This accommodates the closed transition from generator to utility. This technology has been used for many years and has evolved to greater speed of action with advancements in electronic synchronization control andgovernors over mechanical units. A generator synchronizer unit can also be used to hold distributed generators in sync with the utility or each other. This assures the up-stream synchronization required in a distributed redundant design that utilizes Delta Conversion Technology. A PLC controller is used to sense each of the generator and utility voltage references. If a valid utility reference is available, the PLC will provide this reference to the synchronizer units that are connected to the distributed generators. If no utility is available, the PLC will pick an operating generator and use its output as the reference for the others. )
2.An adaptive out-of-step relay [for power system protection]:
Adaptive relaying seeks to make adjustments to the relay characteristics as power system conditions change, thereby making the relay more attuned to the prevailing power system conditions. The work described here began as a theoretical examination of the out-of-step relaying application, its possible shortcomings, and the opportunities to make adaptive improvements. It is shown that for a system that behaves primarily as a two-machine power system, the out-of-step relay could be made more secure by applying the principle of equal area criterion. The newly developed technology of synchronized phasor measurements plays an important role in the realization of this relay.
http://en.wikipedia.org/wiki/Relay
http://www.answers.com/topic/relay
2006-12-21 06:30:29 · answer #1 · answered by Anonymous · 3⤊ 0⤋
Step Generator
2016-12-18 08:38:14 · answer #2 · answered by ? 4 · 0⤊ 0⤋
Well, when alternating current generators are operating in parallel with each other, their frequency must be the same or they will not share the electrical load properly. The problem arises when starting a generator and paralleling it with the ones already operating. If the oncoming generator is not at the same frequency as the operating generators - it jumps to get in step. Sometimes with dramatic results if the frequency is really off.
2006-12-21 05:49:45 · answer #3 · answered by jack w 6 · 0⤊ 2⤋
Out of step ==>> Out of Sync...
You maybe referring to the process of placing more than one generator onto a buss.
In order to place generators in parallel onto an electric distribution system the AC generators must be synchronized with each others frequency and phase.
If the oncomming generator is "not in step" or synchronized with the frequency and phase of the buss it will cause big problems.
Attempting to place a Gen online which is not closely matched frequency wise will cause it to either grab load from other generators or become a load (motorized) itself. . This grabbing or loading of electrical buss upsets the balance with the other generators and can cause generators to trip off line. (Possibly in a cascade effect)
Phase mismatch causes high current spikes which will trip breakers
2006-12-21 06:00:22 · answer #4 · answered by MarkG 7 · 0⤊ 2⤋
If u have 2 generators u must get them in phase sync to combined there power. if they are not in sync. they will fight each other.
2006-12-21 08:21:42 · answer #5 · answered by JOHNNIE B 7 · 0⤊ 1⤋